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1

Al-Anfaji, Ahmed Suaal Bashar. "The optimization of combined power-power generation cycles." Thesis, University of Hertfordshire, 2015. http://hdl.handle.net/2299/15485.

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An investigation into the performance of several combined gas-steam power generating plants’ cycles was undertaken at the School of Engineering and Technology at the University of Hertfordshire and it is predominantly analytical in nature. The investigation covered in principle the aspect of the fundamentals and the performance parameters of the following cycles: gas turbine, steam turbine, ammonia-water, partial oxidation and the absorption chiller. Complete thermal analysis of the individual cycles was undertaken initially. Subsequently, these were linked to generate a comprehensive computer model which was employed to predict the performance and characteristics of the optimized combination. The developed model was run using various input parameters to test the performance of the cycle’s combination with respect to the combined cycle’s efficiency, power output, specific fuel consumption and the temperature of the stack gases. In addition, the impact of the optimized cycles on the generation of CO2 and NOX was also investigated. This research goes over the thermal power stations of which most of the world electrical energy is currently generated by. Through which, to meet the increase in the electricity consumption and the environmental pollution associated with its production as well as the limitation of the natural hydrocarbon resources necessitated. By making use of the progressive increase of high temperature gases in recent decades, the advent of high temperature material and the use of large compression ratios and generating electricity from high temperature of gas turbine discharge, which is otherwise lost to the environment, a better electrical power is generated by such plant, which depends on a variety of influencing factors. This thesis deals with an investigation undertaken to optimize the performance of the combined Brayton-Rankine power cycles' performance. This work includes a comprehensive review of the previous work reported in the literature on the combined cycles is presented. An evaluation of the performance of combined cycle power plant and its enhancements is detailed to provide: A full understanding of the operational behaviour of the combined power plants, and demonstration of the relevance between power generations and environmental impact. A basic analytical model was constructed for the combined gas (Brayton) and the steam (Rankine) and used in a parametric study to reveal the optimization parameters, and its results were discussed. The role of the parameters of each cycle on the overall performance of the combined power cycle is revealed by assessing the effect of the operating parameters in each individual cycle on the performance of the CCPP. P impacts on the environment were assessed through changes in the fuel consumption and the temperature of stack gases. A comprehensive and detailed analytical model was created for the operation of hypothetical combined cycle power and power plant. Details of the operation of each component in the cycle was modelled and integrated in the overall all combined cycle/plant operation. The cycle/plant simulation and matching as well as the modelling results and their analysis were presented. Two advanced configurations of gas turbine cycle for the combined cycle power plants are selected, investigated, modelled and optimized as a part of combined cycle power plant. Both configurations work on fuel rich combustion, therefore, the combustor model for rich fuel atmosphere was established. Additionally, models were created for the other components of the turbine which work on the same gases. Another model was created for the components of two configurations of ammonia water mixture (kalina) cycle. As integrated to the combined cycle power plant, the optimization strategy considered for these configurations is for them to be powered by the exhaust gases from either the gas turbine or the gases leaving the Rankine boiler (HRSG). This included ChGT regarding its performance and its environmental characteristics. The previously considered combined configuration is integrated by as single and double effect configurations of an ammonia water absorption cooling system (AWACS) for compressor inlet air cooling. Both were investigated and designed for optimizing the triple combination power cycle described above. During this research, tens of functions were constructed using VBA to look up tables linked to either estimating fluids' thermodynamic properties, or to determine a number of parameters regarding the performance of several components. New and very interesting results were obtained, which show the impact of the input parameters of the individual cycles on the performance parameters of a certain combined plant’s cycle. The optimized parameters are of a great practical influence on the application and running condition of the real combined plants. Such influence manifested itself in higher rate of heat recovery, higher combined plant thermal efficiency from those of the individual plants, less harmful emission, better fuel economy and higher power output. Lastly, it could be claimed that various concluding remarks drawn from the current study could help to improve the understanding of the behaviour of the combined cycle and help power plant designers to reduce the time, effort and cost of prototyping.
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2

Chan, Siu Man. "Improved speaker verification with discrimination power weighting /." View abstract or full-text, 2004. http://library.ust.hk/cgi/db/thesis.pl?ELEC%202004%20CHANS.

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Thesis (M. Phil.)--Hong Kong University of Science and Technology, 2004.<br>Includes bibliographical references (leaves 86-93). Also available in electronic version. Access restricted to campus users.
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3

Colella, W. G. "Combined heat and power fuel cell systems." Thesis, University of Oxford, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.411153.

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4

Starfelt, Fredrik. "From Combined Heat and Power to Polygeneration." Doctoral thesis, Mälardalens högskola, Framtidens energi, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-28442.

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In order to reach targets on reducing greenhouse gas emissions from fossil resources it is necessary to reduce energy losses in production processes. In polygeneration, several processes are combined to complement each other to avoid sub-optimization of the standalone processes. This thesis addresses polygeneration with focus on Combined Heat and Power (CHP) production integrated with other processes. Biomass-fired CHP plants are commonly dimensioned to have surplus heat production capacity during periods with lower heat demand. At the same time, production of biomass based vehicle fuels and fuel upgrading are heat demanding processes. The opportunity to combine CHP with ethanol production from lignocellulosic feedstock and torrefaction with the aim of replacing fossil fuels are used as cases during the evaluation of polygeneration. Simulation models are used to investigate the performance of CHP integrated with production of ethanol and torrefaction. Measured data from commercial CHP plants have been used to reflect the operation boundaries. The findings show that polygeneration can compete with stand-alone production in both energy and economic performance. Polygeneration offers a wider operating range where reduced minimum load gives increased annual operating time. Therefore, under limited heat demand more renewable electricity production is possible due to increased operating hours and steam extraction from the turbine during part-load operation. Resource availability and fluctuations in fuel price have the largest impact on the profit of polygeneration. Other aspects that have substantial effects on the economy in polygeneration are the electricity spot price and subsidies. Furthermore, it has been proven that the yield of each product in a multiproduct process plant, the size of the plant and the heat demand have a large impact on the economy. Polygeneration turns by-products into buy-products.
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5

Bengtsson, Sara. "Modelling of a Power System in a Combined Cycle Power Plant." Thesis, Uppsala universitet, Elektricitetslära, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-149318.

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Simulators for power plants can be used for many different purposes, like training for operators or for adjusting control systems, where the main objective is to perform a realistic behaviour for different operating conditions of the power plant. Due to an increased amount of variable energy sources in the power system, the role of the operators has become more important. It can therefore be very valuable for the operators to try different operating conditions like island operation. The aim of this thesis is to model the power system of a general combined-cycle power plant simulator. The model should contain certain components and have a realistic behaviour but on the same time be simple enough to perform simulations in real time. The main requirements are to simulate cold start, normal operation, trip of generator, a controlled change-over to island operation and then resynchronisation. The modelling and simulations are executed in the modelling software Dymola, version 6.1. The interface for the simulator is built in the program LabView, but that is beyond the scope of this thesis. The results show a reasonable performance of the power system with most of the objectives fulfilled. The simulator is able to perform a start-up, normal load changes, trip of a generator, change-over to island operation as well as resynchronisation of the power plant to the external power grid. However, the results from the changing-over to island operation, as well as large load losses during island operation, show an unreasonable behaviour of the system regarding the voltage magnitude at that point. This is probably due to limitations in calculation capacity of Dymola, and the problem has been left to further improvements due to lack of time. There has also been a problem during the development of a variable speed regulated induction motor and it has not been possible to make it work due to lack of enough knowledge about how Dymola is performing the calculations. Also this problem has been left to further improvements due to lack of time.
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6

Rosso, Stefano. "Power Plant Operation Optimization Economic dispatch of combined cycle power plants." Thesis, KTH, Skolan för industriell teknik och management (ITM), 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-264350.

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As electricity production from renewable sources increases, higher flexibility is required by fossil fuel generation to cope with the inherent fluctuations of solar and wind power. This results in shorter operating cycles and steeper ramps for the turbines, and more uncertainty for the operators. This thesis work applies mathematical optimization and statistical learning to improve the economic dispatch of a combined cycle power plant composed by two separate blocks of two gas turbines and one steam turbine. The goal is to minimize the input fuel to the gas turbines while respecting a series of constraints related to the demand the plant faces, power generation limits etc. This is achieved through the creation of a mathematical model of the plant that regulates how the plant can operate. The model is then optimized to reduce fuel consumption at a minimum. Machine learning techniques have been applied to sensor data from the plant itself to realistically simulate the behavior of the turbines. Input-Output curves have been obtained for power and exhaust heat generation of all the turbines using ordinary least squares on monthly data with a ten minutes sampling rate. The model is cross-validated and proven statistically valid. The optimization problem is formulated through generalized disjunctive programming in the form of a mixed-integer linear problem (MILP) and solved using a branch-and-bound algorithm. The output of the model is a one-week dispatch, in fifteen minutes intervals, carried out for two months in total. Lower fuel consumption is achieved using the optimization model, with a weekly reduction of fuel consumed in the range of 2-4%. A sensitivity analysis and a correlation matrix are used to highlights the demand and the maximum available capacity as critical parameters. Results show that the most efficient machines (alternatively, the ones with highest available capacity) should be operated at maximum load while still striving for an efficient utilization of the exhaust gas.<br>När elproduktionen från förnybara källor ökar krävs högre flexibilitet av fossil bränsleproduktion för att hantera fluktuationerna från sol- och vindkraft. Detta resulterar i kortare driftscykler och brantare ramper för turbinerna och mer osäkerhet för operatörerna. Detta avhandlingsarbete tillämpar matematisk optimering och statistisk inlärning för att förbättra det ekonomiska utnyttjandet av en kombicykel i ett kraftverk som består av två separata block med två gasturbiner och en ångturbin. Målet är att minimera bränsleförbrukningen hos gasturbinerna samtidigt som man tar hänsyn till en serie av villkor relaterade till efterfrågan som anläggningen står inför, kraftproduktionsbegränsningar etc. Detta uppnås genom skapandet av en matematisk modell för anläggningen som reglerar hur anläggningen kan fungera. Modellen är sedan optimerad för minsta möjliga bränsleförbrukning. Maskinteknik har använts på sensor data från själva anläggningen för att realistiskt simulera turbinernas beteende. In och utdata kurvor har erhållits för kraftproduktion och avgasvärmeproduktion med hjälp av ordinary least squares (OLS) med månads data och med en tio minuters samplingshastighet. Modellen är korsvaliderad och bevisad statistiskt giltig. Optimeringsproblemet formuleras genom en generaliserad disjunktiv programmering i form av ett mixed-integer linear problem (MILP) och löses med hjälp av en Branch-and-Bound algoritm. Resultatet från modellen är en veckas värden, med femton minuters intervall, totalt i två månader. Lägre bränsleförbrukning uppnås med hjälp av optimeringsmodellen, med en vecka minskad bränsleförbrukning i intervallet 2-4%. En känslighetsanalys och en korrelationsmatris används för att visa efterfrågan och den maximala tillgängliga kapaciteten som kritiska parametrar. Resultaten visar att de mest effektiva maskinerna (alternativt de med högsta tillgängliga kapacitet) bör drivas med maximal belastning medan de fortfarande strävar efter ett effektivt utnyttjande av avgaserna.
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7

Harnoto, Monica. "Value of distribution-level reactive power for combined heat and power systems." Thesis, Massachusetts Institute of Technology, 2020. https://hdl.handle.net/1721.1/126901.

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Thesis: M.B.A., Massachusetts Institute of Technology, Sloan School of Management, in conjunction with the Leaders for Global Operations Program at MIT, May, 2020<br>Thesis: S.M., Massachusetts Institute of Technology, Department of Civil and Environmental Engineering, in conjunction with the Leaders for Global Operations Program at MIT, May, 2020<br>Cataloged from the official PDF of thesis.<br>Includes bibliographical references (pages 56-59).<br>As the U.S. electric grid continues to experience an increase in the penetration of distributed energy resources (DER), electric utilities are evaluating new approaches for utilizing DER to help cost-effectively maintain grid resilience and reliability. One such approach is to create a transactive market for DER to provide grid services, which are services required to support reliable grid operation. Though work has been done to understand some of the technical mechanisms of this type of market, gaps still exist in understanding the value and market opportunity of ancillary services at the distribution level. One type of ancillary service - reactive power - is of particular interest because of the theoretic ability to source from existing assets on the distribution network. This paper aims to build understanding of the value of procuring reactive power from one of these assets: Combined Heat and Power (CHP) systems. The value of procuring reactive power from a CHP system will be quantified by 1) characterizing CHP systems' capacity to produce and absorb reactive power, 2) assessing the annual cost of procuring reactive power from CHP systems, and 3) comparing the CHP system technical capability and cost to the utility's conventional solution: capacitor banks. This study finds that, while there are promising scenarios in which CHP systems can technically and economically provide reactive power in a comparable or slightly advantaged manner to capacitor banks, the overall statistics for the 29 CHP systems analyzed in the New York fleet do not conclusively demonstrate an advantage that supports outright replacement of capacitor banks. Further assessment of CHP systems as a complementary source of reactive power and site-specific case studies are recommended to inform the next step in the decision making process for determining whether this path should be pursued as a source of reactive power.<br>by Monica Harnoto.<br>M.B.A.<br>S.M.<br>M.B.A. Massachusetts Institute of Technology, Sloan School of Management<br>S.M. Massachusetts Institute of Technology, Department of Civil and Environmental Engineering
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8

Nalmpantis, Dimitrios. "Combined adaptive power-rate control in CDMA systems." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2001. http://handle.dtic.mil/100.2/ADA397142.

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Thesis (M.S. in Systems Engineering)--Naval Postgraduate School, Sept. 2001.<br>Thesis advisors, Ha, Tri T. ; Tighe, Jan. "September 2001." Includes bibliographical references (p. 35). Also available in print.
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9

Smith, Martin Alan. "Small scale and micro combined heat and power." Thesis, De Montfort University, 1999. http://hdl.handle.net/2086/4178.

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10

Day, Harriet Laura Lavinia. "Sex differences in cued fear discrimination : a combined behavioural, computational and electrophysiological study." Thesis, University of Nottingham, 2018. http://eprints.nottingham.ac.uk/49696/.

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Women are up to twice as likely to suffer from post-traumatic stress disorder (PTSD) than men. Failure to discriminate between cues predicting threat and safety is associated with PTSD, yet sex differences in fear discrimination remain poorly understood. Here, we examined sex differences in auditory fear discrimination in rats using a combination of behavioural, computational and electrophysiological methods. In the initial behavioural study, males and naturally cycling females underwent 1-3 days of discrimination training, consisting of pairings of one tone (CS+) with shock and presentations of another tone (CS-) alone. After one day of training, females, but not males, discriminated between the CS+ and CS-. With 2-3 days of training, however, males discriminated and females generalised between the CS+ and CS-. Further testing also revealed that males successfully encode the CS- as a safety signal, whereas females do not. Using reduced computational models, we investigated how both ‘discrimination’ and ‘generalisation’ phenotypes can be generated in silico. We achieved this through a simulation of neural activity produced via ‘fear’ and ‘safety’ neural sub-populations of the basolateral amygdala (BLA) in response to CS+ and CS- cues. By using a model representation of extended fear discrimination training and retrieval, we found that generalisation between the CS+ and CS- could be produced from reduced inhibition, or increased excitation, of fear neurons. Due to their involvement in regulating learned fear, we additionally aimed to investigate the roles of the prelimbic (PL) and infralimbic (IL) cortices of themedial prefrontal cortex in fear discrimination. By concurrently recording activity from the PL, IL and BLA in awake behaving animals during retrieval of the CS+ and CS- after extended discrimination training, we examined the individual contributions and functional interactions of these regions during this learning paradigm. We found that, in males, the PL showed an increase in power at both theta (4-12 Hz) and gamma (30-120 Hz) frequencies during presentations of the CS- compared to the CS+, whereas this increase was largely absent in females. Taken together, these results indicate that, while females show fear discrimination with limited training, they generalise with extended training. We hypothesised that this generalisation in females is likely due to impaired safety learning, which may result, in part, from sex differences in the neural circuitry underlying fear discrimination.
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11

Liang, Hua. "Viability of stirling-based combined cycle distributed power generation." Ohio : Ohio University, 1998. http://www.ohiolink.edu/etd/view.cgi?ohiou1176484842.

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12

Dogan, Osman Tufan. "Performance Of Combined Cycle Power Plants With External Combustion." Thesis, METU, 2003. http://etd.lib.metu.edu.tr/upload/1223288/index.pdf.

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13

Lome, Ingrid Brandtsegg. "Validation of a Combined Wind and Wave Power Installation." Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for marin teknikk, 2014. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-25638.

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To meet the increasing energy demand of the world it is important to develop technology for harvesting energy from renewable sources. One of the largest renewable energy sources is the world&#146;s oceans, where wind, wave and thermal energy are considered the main sources. Offshore wind and wave technology is emerging; several designs are under development and prototype testing of some technologies has given positive results. It is beneficial to install wind turbines and wave converters on the same foundation as this can reduce costs and facilitate connection to shore.A validation of the combined wind and wave power production platform W2Power has been carried out in this thesis. W2Power is a triangular semi-submersible platform with two wind turbines and ten wave energy converters along the sides. The work has consisted of planning and performing an experimental campaign and making numerical simulation models of the platform. For the experimental campaign only one side of the platform has been considered, this to reduce costs and increase test model accuracy. The main objectives of the experimental campaign were estimation of power production and investigation of the interaction between the wave energy converters. The wave energy converters were tested for operational conditions, both regular and irregular waves. A total of three simulation models have been made using the softwares GeniE, HydroD (Wadam) and SIMA. Of these, two models are of the experimental set-up, where one is tuned to produce the same results as the model tests and one is untuned for comparison, and one model of the entire platform. The two wind turbines integrated in the W2Power design have not been taken into account. The model tests were not performed with optimal load resistance in the air cylinders due to a calculation error made in the beginning of the experimental campaign. This resulted in the air cylinders acting more as springs than dampers, overestimating the actual forces and slightly underestimating the responses of the buoys. Some measurements with optimal load resistance exist, and the estimation of produced power was done based on these. An electricity production of 10 &#150; 400 GWh per year was estimated as a total for all ten wave converters connected to the platform. The expected electricity output of the platform should be in the range of 1 &#150; 10 GWh per year, when compared with other wave energy devices, making the estimations unexpectedly high. The RAOs computed in Wadam for the buoys alone, i.e. not connected to the platform framework, concord with the calculated RAOs from the model test. The heave peak period in Wadam is 6 seconds versus 5.5 seconds for the measured results, while the surge peak periods are 5 versus 5.5 seconds. The heave peak amplitudes varies from 1.9 m/m for 0o incoming angle to 1.3 m/m for 90o and from 0.7 m/m to 0.4 m/m in surge. This concordance implies that the hydrodynamics of the buoys is correctly modelled. The responses measured during the model test and the calculated RAOs revealed that a shadowing effect between the buoys exist: the buoy interacting with the incoming waves first have higher response and forces than the other buoys.The analyses done with the numerical simulation model in SIMA did not give satisfactory results. The rotation point was modelled so that the rotation arms of the buoys were flexible instead of stiff arms rotating about a point. To achieve correct responses large forces were applied to the fixed elongation couplings representing the air cylinders. This led to large vertical forces on the rotation arm that were not consistent with the measured forces. However, the simulated horizontal forces acting on the platform framework were of equal magnitude as the measured for most conditions analysed. The response of the buoys had to be reduced to simulate correct vertical forces, making the numerical model inconsistent with the measured responses. Based on the model test and the estimation of produced power, it was concluded that the W2Power design is feasible.
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14

Homon, Bohdan. "Combined power supply system converting unit with renewable sources." Thesis, Дніпропетровський національний університет залізничного транспорту ім. академіка В. Лазаряна, 2017. https://er.knutd.edu.ua/handle/123456789/9329.

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The article deals with the implementation of renewable energy sources in local electrical systems such as solar battery, wind turbines. The improvement and wide spread of the sources of distributed generation renewable energy sources is one of the ways to improve the energy security of the country.<br>Стаття присвячена питанню впровадження відновлювальних джерел енергії (сонячна батарея, вітрові турбіни) в місцевих електричних системах. Покращення та широке розповсюдження поновлюваних джерел енергії розподіленої генерації є одним із способів підвищення енергетичної безпеки країни.<br>Статья посвящена вопросу внедрения возобновляемых источников энергии (солнечная батарея, ветровые турбины) в местных электрических системах. Улучшение и широкое распространение возобновляемых источников энергии распределенной генерации является одним из способов повышения энергетической безопасности страны.
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15

Rajasekeran, Sangeetha. "Enabling Grid Integration of Combined Heat and Power Plants." Thesis, Virginia Tech, 2020. http://hdl.handle.net/10919/99730.

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In a world where calls for climate action grow louder by the day, the role of renewable energy and energy efficient generation sources has become extremely important. One such energy efficient resource that can increase the penetration of renewable energy into the grid is the Combined Heat and Power technology. Combined Heat and Power (CHP) plants produce useful thermal and electrical power output from a single input fuel source and are widely used in the industrial and commercial sectors for reliable on-site power production. However, several unfavorable policies combined with inconsistent regulations have discouraged investments in this technology and reduced participation of such facilities in grid operations. The potential benefits that could be offered by this technology are numerous - improving grid resiliency during emergencies, deferring transmission system updates and reducing toxic emissions, to name a few. With increased share of renewable energy sources in the generation mix, there is a pressing need for reliable base generation that can meet the grid requirements without contributing negatively to the environment. Since CHP units are good candidates to help achieve this two-fold requirement, it is important to understand the present barriers to their deployment and grid involvement. In this thesis work, we explore some of these challenges and propose suitable grid integration technology as well as market participation approaches for better involvement of distributed CHP units in the industrial and commercial sectors.<br>Master of Science<br>Combined Heat and Power is a generation technology which uses a single fuel source to produce two useful outputs - electric power and thermal energy - by capturing and reusing the exhaust steam by-product. These generating units have much higher efficiencies than conventional power plants, lower fuel emissions and have been a popular choice among several industries and commercial buildings with a need for uninterrupted heat and power. With increasing calls for climate action and large scale deployment of renewable based energy generation sources, there is a higher need for reliable base-line generation which can handle the fluctuations and uncertainty of such renewables. This need can be met by CHP units owing to their geographic distribution and their high operating duration. CHPs also provide a myriad of other benefits for the grid operators and environmental benefits, compared to the conventional generators. However, unfavorable and inconsistent regulatory procedures have discouraged these facility owners from actively engaging in providing grid services. Therefore, it is imperative to look into some of the existing policies and understand where the changes and incentives need to be made. In this work, we look into methods that can ease CHP integration from a technological and an economic point of view, with the aim of encouraging grid operators and CHP owners to be more active participants.
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16

Yilmaz, Oguz. "Participation Of Combined Cycle Power Plants To Power System Frequency Control: Modeling And Application." Master's thesis, METU, 2006. http://etd.lib.metu.edu.tr/upload/12607228/index.pdf.

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This thesis proposes a method and develops a model for the participation of a combined cycle power plant to power system frequency control. Through the period of integration to the UCTE system, (Union for Coordination of Transmission of Electricity in Europe) frequency behavior of Turkey&rsquo<br>s grid and studies related to its improvement had been a great concern, so is the reason that main subject of my thesis became as &ldquo<br>Power System Frequency Control&rdquo<br>. Apart from system-wide global control action (secondary control)<br>load control loops at power plants, reserve power and its provision even at the minimum capacity generation stage, (primary control) are the fundamental concerns of this subject. The adjustment of proper amount of reserve at the power plants, and correct system response to any kind of disturbance, in the overall, are measured by the quality of the frequency behaviour of the system. A simulator that will simulate a dynamic gas turbine and its control system model, together with a combined cycle power plant load controller is the outcome of this thesis.
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17

Lown, Mark. "An integrated combined governor/AVR system." Thesis, Queen's University Belfast, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.268229.

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18

Tiba, Eman. "Arab Americans: The Power of Creative Expression to Combat Discrimination." The Ohio State University, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=osu1524072265195156.

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19

Zheng, J. "Combined pinch and exergy analysis for commercial power plant design." Thesis, University of Manchester, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.532908.

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This thesis addressesth e analysisa nd design of commercial power plants by using the Combined Pinch and Exergy Approach. Current practice in design for commercial power plants heavily relies on experience and computer simulation and lacks systematic design methodologies. On the contrary, Pinch Technology allows systematic and generic approaches to chemical process design in which targets are set prior to design. These approaches can address issues related to process integration and optimisation. This thesis exploits the analogy between power plant design and chemical process design and applies the philosophy of Pinch Technology to the field of power plant design. In this thesis, the "onion" model used to represent the hierarchy of chemical process design is applied to power plant design. This model decomposes the whole design problem into three relatively simple tasks, including turbine system selection, heat exchanger network (HEN) design and fuel supply determination. Complex interactions exist between these individual components. To describe the complex interactions between the different components, a qualitative tool called the Combined Pinch and Exergy Representation (CPER) has been developed. The CPER allows engineers to visualise the overall performance of a power plant and the interactions between components. This diagram can also help engineers to screen design options. A quantitative tool, called the shaftwork targeting approach, has been developed in this thesis to evaluate each possible design option and identify the most promising one ahead of detailed simulation and designA tool called the Exergy Remaining Problem Analysis (ERPA) has been developed to guide HEN design. This allows the design to achieve the shaftwork targets. By evaluating the impact of individual matches on the remaining problem, the ERPA can determine the influence of individual matches on shaftwork generation. By detecting inappropriate matches, the ERPA can ensure that the HEN design meets the shaftwork targets. Based on the "onion" model of power plant, a systematic and generic approach to power plant design has been developed. In this approach, power plant design starts with the turbine system, then moves to the heat exchanger network and the fuel supply. This approach is entirely general which can be applied for design of different power plants. The significance of the new approach is that it enables engineers to screen possible design options with physical understanding and identify the most promising design option ahead of detailed simulation and design. This speeds up the overall design process and ensures that an optimal solution is obtained. vi
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20

Kazuz, Ramadan. "Hybrid solar thermo-electric systems for combined heat and power." Thesis, Cardiff University, 2014. http://orca.cf.ac.uk/72508/.

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Solar energy has been extensively used in the renewable technology field, especially for domestic applications, either for heating, electrical generation or for a combination of heat and power (CHP) in one system. For CHP system solar photoelectric/thermal (PV/T) is the most commonly used technology for roof top applications. However, combination between solar hot water and thermoelectric generators has become an attractive for CHP system, this is due to its simplicity of construction and its high reliability. Moreover, this technology does not rely simply on sunlight and it can work with any other heat source, such as waste heat. However, its main drawback is its low efficiency. Recent publications by Kraemer et al (2011) and Arturo (2013) have shown that the efficiency of solar thermoelectric systems has improved dramatically, especially when combined with a solar concentrator system, as well as within a vacuum environment. The project recorded in this thesis focused on the design, construction and investigation of an experimental solar thermoelectric system based on a flat plate solar absorber. The aim was to study the technical feasibility and economical viability of generating heat and electric power using a solar thermoelectric hot water system. The design procedure involved on determining the heat absorbed and emitted, as well as the electrical power that was generated by the system. It began by obtaining the efficiency of the solar absorber, including selecting its paint, this was done through an experimental technique to determine the heat absorbed by the absorber, and the results obtained were verified by direct measurements of the light intensity. xvi An intensity meter was used, and results from both the experimental and theoretical models showed good agreement. The process also included calculating the heat from the system that was gained, lost and generated, as well as the electrical power provided. This was done to provide the system optimal size optimization to obtain the best and most economical system. Further improvement was made to the system by assembling a vacuum cavity, to improve the system’s efficiency. Although the maximum electrical efficiency obtained was relatively low (0.9%), compared to results recorded in the literature (Kraemer et al ,2011 and Arturo, 2013). However, the results of the electrical power output, under a vacuum level of 5 x 10-2mbar, increased approximately three times compared to the results obtained under normal (atmospheric) conditions. Additionally, the thermal power increased by 37% at this level of vacuum. The process involved determining the best thermoelectric geometries to achieve the optimum power outcome under different environmental conditions. The results showed that the system, which included the Thermoelectric device (TEG) with a larger geometric size, produced the best thermal power among other sizes. It was concluded that the system with the smallest TEG geometric size provided the best electrical power output.
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Tichagwa, Anesu. "Micro combined heat and power management for a residential system." Master's thesis, University of Cape Town, 2013. http://hdl.handle.net/11427/16914.

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Fuel cell technology has reached commercialisation of fuel cells in application areas such as residential power systems, automobile engines and driving of industrial manufacturing processes. This thesis gives an overview of the current state of fuel cell-based technology research and development, introduces a μCHP system sizing strategy and proposes methods of improving on the implementation of residential fuel cell-based μCHP technology. The three methods of controlling residential μCHP systems discussed in this thesis project are heat-led, electricity-led and cost-minimizing control. Simulations of a typical HT PEMFC -based residential μCHP unit are conducted using these control strategies. A model of a residential μCHP system is formulated upon which these simulated tests are conducted. From these simulations, equations to model the costs of running a fuel-cell based μCHP system are proposed. Having developed equations to quantify the running costs of the proposed μCHP system a method for determining the ideal size of a μCHP system is developed. A sizing technique based on industrial CHP sizing practices is developed in which the running costs and capital costs of the residential μCHP system are utilised to determine the optimal size of the system. Residential thermal and electrical load profile data of a typical Danish household are used. Having simulated the system a practical implementation of the power electronics interface between the fuel cell and household grid is done. Two topologies are proposed for the power electronics interface a three-stage topology and a two-stage topology. The efficiencies of the overall systems of both topologies are determined. The system is connected to the grid so the output of each system is phase-shifted and DC injection, harmonic distortion, voltage range and frequency range are determined for both systems to determine compliance with grid standards. Deviations between simulated results and experimental results are recorded and discussed and relevant conclusions are drawn from these.
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Sheikhi, Mehrabadi Elham. "Multi-Objective Optimization of Combined Heat and Power Industrial Microgrid." Thesis, The University of Sydney, 2020. https://hdl.handle.net/2123/21868.

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With the advent of distributed energy resources (DERs), such as solar photovoltaic (PV), distributed storages (DSs), and combined heat and power (CHP) generators, an opportunity was given to various customers to be satisfied with their local electricity and heat providers. Microgrid is a small-scale, localized power network that encompasses DERs, loads, and controllers. Microgrids could be a promising alternative for the conventional power system to solve environmental and economic concerns. Recently, CHP-based microgrids have widely attracted attention due to the cost effectiveness and pollution reduction. Most of the recent studies attempted to simplify microgrid components, loads, and constraints to decrease the analysis complexity; however, in this work, a comprehensive study of an industrial microgrid (IMG) comprising natural gas-based CHPs with different generation limits, PVs with intermittent outputs, PV storages, and boilers is taken into the consideration to totally satisfy variant electrical and heat demand over 24-hour period. Emission and cost are conflicting concerns in microgrid generation scheduling optimization and simultaneous optimization of these objectives was challenging. Optimization process is viable using various algorithms and techniques. Among all different approaches, NSGA-II and PSO are among the top-rated algorithms. In this innovative study, NSGA-II and PSO have been developed to reduce cost and emission objectives simultaneously with applying the most critical constraints and variable loads. The practical ability of the optimization process using the applied algorithms are demonstrated by analyzing two scenarios at the presence and absence of PV systems. Although both methods could satisfy electrical and thermal demands, the NSGA-II presented an improved solution compared to PSO method. Also, PV system effect on cost and pollution reduction was significant.
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Aghaeimeybodi, Mehdi. "Optimum Prime Mover Sizing in Combined Heat and Power Systems." Thesis, The University of Sydney, 2013. http://hdl.handle.net/2123/10298.

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Combined heat and power (CHP) systems due to their high efficiency compared to the conventional power generation systems have received considerable attention as they have less harmful impact on the environment. Optimum selection of prime movers in CHP systems is of crucial importance due to the fact that inappropriate choices reduce the benefits of CHP systems considerably. In the selection procedure the performance characteristics of prime movers as well as economic parameters should be taken into consideration. As a variant of CHP systems, trigeneration systems are formed by adding an absorption chiller to combined heat and power systems to convert some of the recovered heat into required cooling loads. This results in a more efficient use of energy as the heat demand is subject to seasonal variations. In this thesis, thermo-economic approaches to selecting the optimum prime movers of small and medium scale CHP and turbine-based trigeneration systems as well as planning their operational strategy are studied. The prime movers considered include microturbine, gas turbine, internal combustion engines, and Stirling engine. Appropriate relations for estimating thermodynamic and economic parameters of the system in the context of Net Annual Cost (NAC) as well as Net Present Worth (NPW) criteria are introduced. As the commonly applied methods of dealing with the environmental concerns, the impact of a carbon tax as well as an emissions trading scheme has also been studied. For the purpose of demonstration, the developed methodologies have been used to optimally size potential prime movers of a number of operational case studies and to determine their operational strategy. Further, to determine the sensitivity of results to input parameters (e.g. electricity price) comprehensive sensitivity analyses have been conducted.
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24

Pearce, James Michael. "Combined heat and power in the home : a realistic concept?" Thesis, University of Manchester, 1995. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.488114.

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Al-Hamdan, Qusai Zuhair Mohammed. "Design criteria and performance of gas turbines in a combined power and power (CPP) plant for electrical power generation." Thesis, University of Hertfordshire, 2002. http://hdl.handle.net/2299/14041.

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The simple gas turbine engine Operates on the basic Joule-Brayton cycle and it is notorious for its poor thermal efficiency. Several modifications have been made to the simple cycle in order to increase its thermal efficiency but, within the thermal and mechanical stress constrains, the efficiency still ranges between 28 and 35%. However, higher values of energy utilisation efficiency have been claimed in recent years by using low grade heat from the engine exhaust either for district heating or for raising low pressure steam for chemical processes. Both applications are not very attractive in hot countries. The concept of using the low grade thermal energy from the gas turbine exhaust to raise steam in order to drive a steam turbine and generate additional electricity, i. e. the combined power and power or CPP plant would be more attractive in hot countries than the CHP plant. It was hypothesized that the operational parameters, hence the performance of the CPP plant, would depend on the allowable gas turbine entry temperature. Hence, the exhaust gas temperature could not be decided arbitrarily. This thesis deals with the performance of the gas turbine engine operating as a part of the combined power and power plant. In a CPP plant, the gas turbine does not only produce power but also the thermal energy that is required to operate the steam turbine plant at achievable thermal efficiency. The combined gas turbine-steam turbine cycles are thermodynamically analysed. A parametric study for different configurations of the combined gas-steam cycles has been carried out to show the influence of the main parameters on the CPP cycle performance. The parametric study was carried out using realistic values in view of the known constraints and taking into account any feasible future developments. The results of the parametric study show that the maximum CPP cycle efficiency would be at a point for which the gas turbine cycle would have neither its maximum efficiency nor its maximum specific work output. It has been shown that supplementary heating or gas turbine reheating would decrease the CPP cycle efficiency; hence, it could only be justified at low gas turbine inlet temperatures. Also it has been shown that although gas turbine intercooling would enhance the performance of the gas turbine cycle, it would have only a slight effect on the CPP cycle performance. A graphical method for studying operational compatibility, i.e. matching, between gas turbine components has been developed for a steady state or equilibrium operation. The author would like to submit that the graphical method offers a novel and easy to understand approach to the complex problem of component matching. It has been shown that matching conditions between the compressor and the turbine could be satisfied by superimposing the turbine performance characteristics on the compressor performance characteristics providing the axes of both were normalised. This technique can serve as a valuable tool to determine the operating range and the engine running line. Furthermore, it would decide whether the gas turbine engine was operating in a region of adequate compressor and turbine efficiencies. A computer program capable of simulating the steady state off-design conditions of the gas turbine engine as part of the CPP plant has been developed. The program was written in Visual Basic. Also, another program was developed to simulate the steady state off-design operation of the steam turbine power plant. A combination of both programs was used to simulate the combined power plant. Finally, it could be claimed that the computer simulation of the CPP plant makes significant contribution to the design of thermal power plants as it would help in investigating the effects of the performance characteristics of the components on the performance of complete engines at the design and off-design conditions. This investigation of the CPP plant performance can be carried out at the design and engineering stages and thus help to reduce the cost of manufacturing and testing the expensive prototype engines.
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26

Mihailescu, Virgiliu. "Regulatory issues related to the operation of combined heat and power plants in liberalised markets : Policy suggestions for Moldova District heating combined heat and power plants." Thesis, University of Dundee, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.505591.

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27

Hassan, Mohamed Elhafiz. "Power Plant Operation Optimization : Unit Commitment of Combined Cycle Power Plants Using Machine Learning and MILP." Thesis, mohamed-ahmed@siemens.com, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-395304.

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In modern days electric power systems, the penetration of renewable resources and the introduction of free market principles have led to new challenges facing the power producers and regulators. Renewable production is intermittent which leads to fluctuations in the grid and requires more control for regulators, and the free market principle raises the challenge for power plant producers to operate their plants in the most profitable way given the fluctuating prices. Those problems are addressed in the literature as the Economic Dispatch, and they have been discussed from both regulator and producer view points. Combined Cycle Power plants have the privileges of being dispatchable very fast and with low cost which put them as a primary solution to power disturbance in grid, this fast dispatch-ability also allows them to exploit price changes very efficiently to maximize their profit, and this sheds the light on the importance of prices forecasting as an input for the profit optimization of power plants. In this project, an integrated solution is introduced to optimize the dispatch of combined cycle power plants that are bidding for electricity markets, the solution is composed of two models, the forecasting model and the optimization model. The forecasting model is flexible enough to forecast electricity and fuel prices for different markets and with different forecasting horizons. Machine learning algorithms were used to build and validate the model, and data from different countries were used to test the model. The optimization model incorporates the forecasting model outputs as inputs parameters, and uses other parameters and constraints from the operating conditions of the power plant as well as the market in which the plant is selling. The power plant in this mode is assumed to satisfy different demands, each of these demands have corresponding electricity price and cost of energy not served. The model decides which units to be dispatched at each time stamp to give out the maximum profit given all these constraints, it also decides whether to satisfy all the demands or not producing part of each of them.
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28

Huang, Belinda. "Gender, race, and power : the Chinese in Canada, 1920-1950." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape11/PQDD_0002/MQ43885.pdf.

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29

Tamm, Gunnar Olavi. "Experimental investigation of an ammonia-based combined power and cooling cycle." [Gainesville, Fla.]: University of Florida, 2003. http://purl.fcla.edu/fcla/etd/UFE0000802.

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30

Han, Song. "Regional Energy Systems with Retrofitted Combined Heat and Power (CHP) Plants." Doctoral thesis, Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-15966.

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Fossil fuel depletion, economic development, urban expansion and climate change present tough challenges to municipal- and regional-scale energy systems. Regional energy system planning, including waste treatment, renewable energy supply, energy efficiency, and climate change, are considered essential to meet these challenges and move toward a sustainable society. This thesis includes studies on energy system from municipal waste, potential for a fossil fuel-independent regional energy system with increased renewable energy products using waste as one of energy sources, and the performance of biomass-fired combined heat and power (CHP) plants. A top-down method is adopted to organize the studies, from national waste-to-energy (WtE) scenarios to individual energy plants. The first study considers the overall potential contribution of WtE to energy supply and greenhouse gas (GHG) emissions mitigation in Sweden until 2050 under several different scenarios. Depending on WtE scenario considered, the study shows that WtE can supply energy between 38 and 186 TWh and mitigate between CO2 of 1 and 12 Mt per year by 2050 based on the baseline of year 2010. At a regional level, static and dynamic optimization models with a focus on WtE are developed for two regions in Sweden and Finland. The former is used to investigate the possibilities of optimal positioning of new energy plants, retrofitting existing energy plants and planting energy crops. The latter case study is on regional heat and power production using biogas generated from agricultural and livestock wastes. Centralized biogas production units perform better than distributed production regarding energy and carbon balance though the net energy output is negligible. However, a significant GHG emission can be reduced compared to the present status. Retrofitting existing conventional CHP plants is another option for improving regional energy system. The study shows that integrating heat-demanded processes such as drying, bioethanol and pellet production with existing CHP plants can improve overall energy efficiency and power output, increase annual operation time and reduce production cost as well as mitigate GHG emissions.  It is recommended that building new WtE/energy plants at optimum sites, upgrading the existing energy plants, expanding the agricultural/forestry waste/residues output (biomass) and planting more energy crops shall be taken into considerations for the future regional energy systems.<br>Utarmning av fossila bränslekällor, ekonomisk utveckling, städernas utbredning och klimatförändring är svåra utmaningar för kommunala- och regionala energisystem. Planering av det regionala energisystemet, inklusive avfallshantering, förnyelsebara energikällor, energieffektivisering och hänsyn till klimatförändringar, anses avgörande för att möta dessa utmaningar och gå mot ett hållbart samhälle. Denna avhandling innehåller studier av energisystem centrerad kring hushållsavfall, potentialet för fossilbränslefria regionala energisystem som utnyttjar ökad andel förnyelsebara energiprodukter med avfall som en energikälla och prestandautvärdering av ett biomassa-eldat kraftvärmeverk. Studierna har organiserats efter storlek på system, från nationella avfall-till-energi scenarier till enskilda kraftverk.   Den första studien behandlar övergripande möjligheten att genom avfall-till-energi bidra till energiförsörjningen och begränsa utsläppet av växthusgaser i Sverige till 2050 under flera olika scenarier. Beroendet på avfall-till-energiscenario visar studien att genom att utnyttja avfall kan mellan 38 och 186 TWh energi levereras och dessutom kan koldioxidutsläppen reduceras med 1-12 miljoner ton till år 2050 med 2010 som basår.   På den regionala nivån, statiska och dynamiska optimeringsmodeller, med fokus på avfall-till-energi, är utvecklats för två regioner, en i Sverige och en i Finland. Det första modellen används för hitta den optimala placeringen av nya energianläggningar, anpassning av befintliga anläggningar och placering av odlingar av energigrödor. Den senare ingår i en fallstudie av den regionala kraft- och värmeproduktionen genom utnyttjande av biogas producerad från jordbruksavfall och djurgödsel. Centraliserade biogasanläggningar presterar bättre än decentraliserad anläggningar när det gäller energi – och kolbalanser även om i båda fallen så är skillnaden mellan konsumerad mängd bränsle, värme och el och producerad värme och el försumbar. Däremot kan en betydande mängd av växthusgasutsläppet i båda fallen undvikas jämfört med nuläget.   Anpassning av befintliga konventionella kraftvärmeverk är ett annat alternativ för att förbättra det regionala energisystemet. Studien visar att genom att integrera värmekrävande processer såsom torkning, bioetanol- och pelletsproduktion med befintliga kraftvärmeverk kan den totala energieffektiviten och uteffekten förbättras, öka den årliga drifftiden och minska produktionskostnaderna och utsläppen av växthusgaser.   Rekommendationen är att för de framtida regionala energisystemen överväga att bygga nya avfall-till-energianläggningar med optimal placering, uppgradera befintliga energianläggningar utöka insamlandet av avfall/restprodukter från jord- och skogbruk och plantera mer energigrödor.
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31

Karrari, M. "Modelling and adaptive regulation of combined heat and power (CHP) systems." Thesis, University of Sheffield, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.339930.

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32

Kandil, Sherif M. "Analysis and optimization of a jet-pumped combined power/refrigeration cycle." [Gainesville, Fla.] : University of Florida, 2006. http://purl.fcla.edu/fcla/etd/UFE0013733.

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33

Bhatt, Dhruv. "Economic Dispatch of the Combined Cycle Power Plant Using Machine Learning." Thesis, KTH, Skolan för elektroteknik och datavetenskap (EECS), 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-266110.

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Combined Cycle Power Plant (CCPP)s play a key role in modern powersystem due to their lesser investment cost, lower project executiontime, and higher operational flexibility compared to other conventionalgenerating assets. The nature of generation system is changing withever increasing penetration of the renewable energy resources. Whatwas once a clearly defined generation, transmission, and distributionflow is shifting towards fluctuating distribution generation. Because ofvariation in energy production from the renewable energy resources,CCPP are increasingly required to vary their load levels to keep balancebetween supply and demand within the system. CCPP are facingmore number of start cycles. This induces more stress on the gas turbineand as a result, maintenance intervals are affected.The aim of this master thesis project is to develop a dispatch algorithmfor the short-term operation planning for a combined cyclepower plant which also includes the long-term constraints. The longtermconstraints govern the maintenance interval of the gas turbines.These long-term constraints are defined over number of EquivalentOperating Hours (EOH) and Equivalent Operating Cycles (EOC) forthe Gas Turbine (GT) under consideration. CCPP is operating in theopen electricity market. It consists of two SGT-800 GT and one SST-600 Steam Turbine (ST). The primary goal of this thesis is to maximizethe overall profit of CCPP under consideration. The secondary goal ofthis thesis it to develop the meta models to estimate consumed EOHand EOC during the planning period.Siemens Industrial Turbo-machinery AB (SIT AB) has installed sensorsthat collects the data from the GT. Machine learning techniqueshave been applied to sensor data from the plant to construct Input-Output (I/O) curves to estimate heat input and exhaust heat. Resultsshow potential saving in the fuel consumption for the limit on CumulativeEquivalent Operating Hours (CEOH) and Cumulative EquivalentOperating Cycles (CEOC) for the planning period. However, italso highlighted some crucial areas of improvement before this economicdispatch algorithm can be commercialized.<br>Kombicykelkraftverk spelar en nyckelroll i det moderna elsystemet pågrund av den låga investeringskostnaden, den korta tiden för att byggaett nytta kraftverk och hög flexibilitet jämfört med andra kraftverk.Elproduktionssystemen förändras i takt med en allt större andel förnybarelproduktion. Det som en gång var ett tydligt definierat flödefrån produktion via transmission till distribution ändrar nu karaktärtill fluktuerande, distribuerad generering. På grund av variationernai elproduktion från förnybara energikällor finns ett ökat behov avatt kombicykelkraftverk varierar sin elproduktion för att upprätthållabalansen mellan produktion och konsumtion i systemet. Kombicykelkraftverkbehöver startas och stoppas oftare. Detta medför mer stresspå gasturbinen och som ett resultat påverkas underhållsintervallerna.Syftet med detta examensarbete är att utveckla en algoritm för korttidsplaneringav ett kombicykelkraftverk där även driften på lång siktbeaktas. Begränsningarna på lång sikt utgår från underhållsintervallenför gasturbinerna. Dessa långsiktiga begränsningar definieras som antaletekvivalenta drifttimmar och ekvivalenta driftcykler för det aktuellakraftverket. Kombikraftverket drivs på den öppna elmarknaden.Det består av två SGT-800 GT och en SST-600 ångturbin. Det främstamålet med examensarbetet är att maximera den totala vinsten förkraftverket. Ett sekundärt mål är att utveckla metamodeller för attskatta använda ekvivalenta drifttimmar och ekvivalenta driftcyklerunder planeringsperioden.Siemens Industrial Turbo-machinery AB (SIT AB) har installeratsensorer som samlar in data från gasturbinerna. Maskininlärningsteknikerhar tillämpats på sensordata för att konstruera kurvor för attuppskatta värmetillförseln och avgasvärme. Resultaten visar en potentiellbesparing i bränsleförbrukningen om de sammanlagda ekvivalentadrifttimmarna och de sammanlagda ekvivalenta driftcyklernabegränsas under planeringsperioden. Det framhålls dock också att detfinns viktiga förbättringar som behövs innan korttidsplaneringsalgoritmenkan kommersialiseras.
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34

Yevalkar, Amol. "Integrated Combined Heat and Power Plant with Borehole Thermal Energy Storage." Thesis, KTH, Skolan för industriell teknik och management (ITM), 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-266787.

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Countries like Sweden, that experience temperatures below 0 𝑜C, have a high heating demand during winters. The heating demand in Sweden is satisfied through district heating, electric heating, heat pumps and biofuel boilers. The fossil fuels account for around 5 % of the heating market. Sweden is currently looking for alternative solutions in order to replace the fossil fuels. One of the solutions being studied is to have a Borehole Thermal Energy Storage (BTES) system that can store the excess heat produced from a Combined Heat and Power (CHP) plant during the summer. In previous studies, a dynamic model of BTES system was developed which was limited for a specific case. In order to design the BTES systems for different cases as well, a generic steady-state sizing model was developed. This generic steady-state sizing model is flexible can be used to determine the size of BTES in terms of number of boreholes, borehole depth, etc. as per the requirements of the user. Few key results for different input parameters from the newly developed steady-state sizing model and the existing dynamic model were compared for several simulations in order to validate the new steady-state model. The results for a reference case of 240 m borehole depth and 0.8 kg/s mass flow rate in the borehole loop were presented. Further a sensitivity analysis was done by varying the borehole depth and the mass flow rate in the borehole loop. It showed that the Net Present Value (NPV) of the entire system after 20 years and BTES efficiency were higher for lower borehole depth and higher mass flow rate in the borehole loop.<br>Länder som Sverige, som upplever temperaturer under 0 𝑜C, har ett högt värmebehov under vintrarna. Värmebehovet i Sverige tillgodoses genom fjärrvärme, elvärme, värmepumpar och pannor eldade med biobränsle. Fossila bränslen står för cirka 5 % av värmemarknaden. Sverige letar för närvarande efter alternativa lösningar för att ersätta de fossila bränslena. En av lösningarna som studeras är att ha värmelagring i borrhål (Borehole Thermal Energy Storage, BTES) som kan lagra överskottsvärmen som produceras från en kraftvärmeanläggning under sommaren. I tidigare studier utvecklades en dynamisk modell av ett BTES-system som var begränsat till ett specifikt fall. För att utforma BTES-system även för andra fall, utvecklades en generisk modell. Denna generiska dimensioneringsmodell för stabiliseringsstatus är flexibel och kan användas för att bestämma storleken på BTES när det gäller antalet borrhål, borrhålsdjup etc. enligt användarens krav. Några nyckelresultat för olika ingångsparametrar från den nyutvecklade statiska dimensioneringsmodellen och den befintliga dynamiska modellen jämfördes för flera simuleringar för att validera den nya statiska modellen. Resultaten för ett referensfall på 240 m borrhålsdjup och 0,8 kg/s massflödeshastighet i borrhålslingan presenterades. Dessutom utfördes en känslighetsanalys genom att variera borrhålens djup och massflödeshastigheten i borrhålslingan. Det visade sig att både nettonuvärdet (net present value, NPV) för hela systemet efter 20 år och BTES-effektiviteten var högre för lägre borrhåldjup och högre massflödeshastighet i borrhålsslingan.
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35

Sayyah, Ali Afkari. "The design of power combined oscillators suitable for millimetre-wave development." Title page, contents and abstract only, 1997. http://web4.library.adelaide.edu.au/theses/09PH/09phs275.pdf.

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36

Qur'an, Omar Ali Sammour. "Design criteria and performance of steam turbines in a CPP plant for electrical power generation." Thesis, University of Hertfordshire, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.247306.

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37

Bouzguenda, Mounir. "Study of the combined cycle power plant as a generation expansion alternative." Thesis, Virginia Polytechnic Institute and State University, 1987. http://hdl.handle.net/10919/101165.

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Analysis of future alternatives for US utilities is needed as a part of evaluating the impact of combined cycle and phased-construction of integrated coal gasifier power plants on generation expansion. The study encompassed both large and small electric utilities and long-run, least-cost expansion plan for the generating system and studies of the short-run production cost of electrical generation for selected years. The long-run studies were carried out using the Wien Automatic System Planning Package (WASP-II). The optimal combined cycle penetration level was determined for a set of assumptions that involve economics, new technology trends, and feasibility as well as the utility's existing capacity and load forecast. Additional cases were run to account for phased construction and coal gasification. Two electric utilities were selected in this study. These are a U.S. southeastern utility the Bangladesh Electric Utility. The former was chosen as the large utility. The latter was considered a small size utility. WASP-II enhancements enabled us to run cases using IBM-RT and to account for phased construction. The sensitivity studies involved the penetration levels, the fuel supply (oil and natural gas), and economic dispatch of coal gasifiers in particular, and combined cycle power plants in general. Load forecast, and availability of hydroelectric energy were kept uniform. However, adding new power plants and retiring old ones were considered to achieve a more economical and reliable planning strategy while considering issues of technical feasibility.<br>M.S.
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38

Child, D. "Long-term performance modelling of a combined energy generation system." Thesis, Loughborough University, 1996. https://dspace.lboro.ac.uk/2134/32392.

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The installation of the combined energy generation system at West Beacon Farm, Loughborough, Leicestershire commenced in 1988, since when it has steadily grown in both generating capacity and operating complexity. It now consists of three electrical generating sources: two 25kW fixed speed horizontal axis wind turbines, a 6kWp photovoltaic array consisting of both monocrystalline and polycrystalline cells and a 15kW combined heat and power unit which also provides 38kW of thermal energy. Electricity is stored in a 184kWh lead acid battery, and also imported and exported from the grid. Previous research on the system was limited, due to lack of detailed system information and time. Therefore the aim of this research project has been to develop a more detailed and accurate computer model of the system that enables the present operating strategy to be evaluated, together with the effects on the system of changing this strategy. The outcome will be to optimize the generating cost and to provide a model with the flexibility to investigate the conditions in other hybrid systems.
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39

Sinha, Ashok. "A simulation model of a combined wind/reservoir/diesel power generation scheme." Thesis, University of Cambridge, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.335785.

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40

Raja, Nouman Saeed. "Combined source-channel coding for a power and bandwidth constrained noisy channel." Texas A&M University, 2003. http://hdl.handle.net/1969.1/1589.

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This thesis proposes a framework for combined source-channel coding under power and bandwidth constrained noisy channel. The framework is then applied to progressive image coding transmission using constant envelope M-ary Phase Shift Key (MPSK) signaling over an Additive White Gaussian Channel (AWGN) channel. First the framework for uncoded MPSK signaling is developed. Then, it’s extended to include coded modulation using Trellis Coded Modulation (TCM) for MPSK signaling. Simulation results show that coded MPSK signaling performs 3.1 to 5.2 dB better than uncoded MPSK signaling depending on the constellation size. Finally, an adaptive TCM system is presented for practical implementation of the proposed scheme, which outperforms uncoded MPSK system over all signal to noise ratio (Es/No) ranges for various MPSK modulation formats. In the second part of this thesis, the performance of the scheme is investigated from the channel capacity point of view. Using powerful channel codes like Turbo and Low Density Parity Check (LDPC) codes, the combined source-channel coding scheme is shown to be within 1 dB of the performance limit with MPSK channel signaling.
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41

Horkeby, Kristofer. "Simulation of Heat Recovery Steam Generator in a Combined Cycle Power Plant." Thesis, Linköpings universitet, Institutionen för systemteknik, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-75836.

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This thesis covers the modelling of a Heat Recovery Steam Generator (HRSG) in a Combined Cycle Power Plant(CCPP). This kind of power plant has become more and more utilized because of its high efficiency and low emissions. The HRSG plays a central role in the generation of steam using the exhaust heat from the gas turbine. The purpose of the thesis was to develop efficient dynamic models for the physical components in the HRSG using the modelling and simulation software Dymola. The models are then to be used for simulations of a complete CCPP.The main application is to use the complete model to introduce various disturbances and study their consequences inthe different components in the CCPP by analyzing the simulation results. The thesis is a part of an ongoingdevelopment process for the dynamic simulation capabilities offered by the Solution department at SIT AB. First, there is a theoretical explanation of the CCPP components and control system included in the scope of this thesis. Then the development method is described and the top-down approach that was used is explained. The structure and equations used are reported for each of the developed models and a functional description is given. Inorder to ensure that the HRSG model would function in a complete CCPP model, adaptations were made and tuning was performed on the existing surrounding component models in the CCPP. Static verifications of the models are performed by comparison to Siemens in-house software for static calculations. Dynamic verification was partially done, but work remains to guarantee the validity in a wide operating range. As a result of this thesis efficient models for the drum boiler and its control system have been developed. An operational model of a complete CCPP has been built. This was done integrating the developed models during the work with this thesis together with adaptations of already developed models. Steady state for the CCPP model is achieved during simulation and various disturbances can then be introduced and studied. Simulation time for a typical test case is longer than the time limit that has been set, mainly because of the gas turbine model. When using linear functions to approximate the gas turbine start-up curves instead, the simulation finishes within the set simulation time limit of 5 minutes for a typical test case.
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42

Shaneb, Omar Ali. "Optimisation and operation of residential micro combined heat and power (μCHP) systems". Thesis, Durham University, 2012. http://etheses.dur.ac.uk/4432/.

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In response to growing concerns regarding global warming and climate change, reduction of CO2 emissions becomes a priority for many countries, especially the developed ones such as the UK. Residential applications are considered among the most important areas for substantial reduction of CO2 emissions because they represent a major part of the total consumed energy in those countries. For instance, in the UK, residential applications are currently accountable for about 150 Mt CO2 emissions, which represents approximately 25% of the whole CO2 emissions [1-2]. In order to achieve a significant CO2 reduction, many strategies must be adopted in the policy of these countries. One of these strategies is to introduce micro combined heat and power (μCHP) systems into residential energy systems, since they offer several advantages over traditional systems. A significant amount of research has been carried out in this field; however, in terms of integrating such systems into residential energy systems, significant work is yet to be conducted. This is because of the complexity of these systems and their interdependency on many uncertain variables, energy demand of a house is a case in point. In order to achieve such integration, this research focuses on the optimisation and operation of μCHP systems in residential energy systems as essential steps towards integration of these systems, so it deals with the optimisation and operation of a μCHP system within a building taking into account that the system is grid-connected in order to export or import electricity in certain cases. A comprehensive review that summarises key points that outline the trend of previous research in this field has been carried out. The reviewed areas include: technologies used as residential μCHP units, modelling of the μCHP systems, sizing of μCHP systems and operation strategies used for such systems. To further this, a generic model for sizing of μCHP system’s components to meet different residential application has been developed by the author. Two different online operation strategies of residential μCHP systems, namely: an online linear programming optimiser (LPO) and a real time fuzzy logic operation strategy (FLOS) have been developed. The performance of the novel online operation strategies, in terms of their ability to reduce operation costs, has been evaluated. Both the LPO and the FLOS were found to have their advantages when compared with the traditional operation strategies of μCHP systems in terms of operation costs and CO2 emissions. This research should therefore be useful in informing design and operation decisions during developing and implementing μCHP technologies in residential applications, especially single dwellings.
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43

Moradi, Mohammed Hasan. "New modelling and control methods with application to combined cycle power plants." Thesis, University of Strathclyde, 2002. http://oleg.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=21157.

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This thesis reports the analysis and modelling required to build a software simulation of combine cycle power plants. A new MIMO PID controller tuning method and a novel predictive PID controller design method for MIMO systems are also described in the thesis. The emphasis of this work is on simulation; identification and controller design methods. The thesis begins with an account of the combined cycle power plant modelling and simulation development. This culminates in a library of different blocks and subsystems of combined cycle power plants. The simulation development shows how the steady state and dynamic behaviour of combined cycle power plants can be simulated and implemented in the SMULINK and MATLAB environment using per unit models, which are suitable for control design. In the identification stage, the relay identification method is used to identify the critical points of the system for a newly defined criterion at bandwidth frequency. Then, the identified critical points are used to tune PID controllers. The thesis then outlines multivariable PID tuning methods and makes a comparison between these methods and the new relay identification method concerning their robustness for MIMO systems. The last two chapter of thesis are concerned with a new predictive PID controller design method for both SISO and MIMO systems. This methodology is concerned with the design of PID controllers, which have similar features to the model-based predictive controller. Generalized Predictive Control (GPC) design principles are used to develop the PID control with predictive capabilities for both SISO and MIMO systems. The combined cycle power plant simulation, especially the boiler subsystem, is used as an example throughout the thesis.
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44

Araoz, Ramos Joseph Adhemar. "Thermodynamic analysis of Stirling engine systems : Applications for combined heat and power." Doctoral thesis, KTH, Kraft- och värmeteknologi, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-163048.

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Increasing energy demands and environmental problems require innovative systems for electrical and thermal energy production. In this scenario, the development of small scale energy systems has become an interesting alternative to the conventional large scale centralized plants. Among these alternatives, small scale combined heat and power (CHP) plants based on Stirling Engines (SE) have attracted the interest among research and industry due to the potential advantages that offers. These include low maintenance, low noise during operation, a theoretically high electrical efficiency, and principally the fuel flexibility that the system offers. However, actual engine performances present very low electrical efficiencies and consequently few successful prototypes reached commercial maturity at elevated costs.Considering this situation, this thesis presents a numerical thermodynamic study for micro scale CHP-SE systems. The study is divided in two parts: The first part covers the engine analysis; and the second part studies the thermodynamic performance of the overall CHP-SE system. For the engine analysis a detailed thermodynamic model suitable for the simulation of different engine configurations was developed. The model capability to predict the engine performance was validated with experimental data obtained from two different engines: The GPU-3 Stirling engine studied by Lewis Research Centre; and the Genoa engine studied on the experimental rig built at the Energy Department at the Royal Institute of Technology (KTH). The second part of the research complemented the study with the analysis of the overall CHP-SE system. This included numerical simulations of the different CHP components and the sensitivity analysis for selected design parameters.The complete study permitted to assess the different operational and design configurations for the engine and the CHP components. These improvements could be implemented for test field evaluations and thus foster the development of more efficient SE-CHP systems. In addition, the detailed thermodynamic-design methodology for the SE-CHP systems was established and the numerical tool for the design assessment was developed.<br><p>QC 20150327</p>
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45

Williams, Jonathan Mark. "Energy utilisation and combined heat & power sizing in the health service." Thesis, Cardiff University, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.273836.

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46

Smith, P. J. "Predicting hot corrosion rates under coal fired combined cycle power plant conditions." Thesis, Cranfield University, 1994. http://dspace.lib.cranfield.ac.uk/handle/1826/10512.

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Type 11 hot corrosion has been identified as a major life limiting factor of gas turbine components in the topping cycle of coal fired combined cycle power plant. Impurities in the coal combustion gases provide the environmental contaminants necessary for type 11 hot corrosion to occur. It is the purpose of the present study to develop corrosion lifting models such that corrosion rates and thus component lives in coal fired combined cycle plant gas turbines may be accurately predicted thus minimising efficiency losses and plant downtime due to corrosion related problems. Type 11 hot corrosion has been shown to follow bi11lodal distributions which cannot be modelled using the well known mathematical models. It has been shown that a probabilistic approach to modelling is appropriate and that the Gumbel Type I extreme value model of maxima can be used to model the maximum extreme corrosion data This is appropriate as it is the maximum extreme corrosion which in life limiting in the plant gas turbine. Basic corrosion data has been generated through a series of laboratory hot corrosion tests designed to simulate the ambient conditions within the plant gas turbine. The variables having most influence on the corrosion process have been identified as ; temperature, thermal cycling, alkali (Na + K) metal sulphate deposition rate, S02 and HCl in the ambient atmosphere. The corrosion models have been developed from this data which accurately predict the type 11 hot corrosion rates observed in the coal fired gas turbine of a combined cycle power plant .
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Ghashami, Bahman. "A New Power Storage, Cooling Storage, and Water Production Combined Cycle (PCWCC)." Thesis, Högskolan i Gävle, Energisystem, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-22725.

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Fresh water shortage and hot weather are common challenges in many countries of the world. In the other hand, the air conditioning systems which are used for indoor cooling cause peak electricity demand during high temperatures hours. This peak hour demand is very important since it is more expensive and mainly is supplied by fossil fuel power plants with lower efficiencies compare to base load fossil fuel or renewable owe plants. Moreover, these peak electricity load fossil fuel power plants cause higher green house gas emission and other environmental effects. So, all these show that any solution for these problems could make life better in those countries and all over the world.In this thesis, a new idea for a Power storage, Cooling storage, and Water production Combined Cycle (PCWCC) is introduced and reviewed. PCWCC is combination of two thermal cycles, Ice Thermal Energy Storage (ITES) and desalination by freezing cycle, which are merged together to make a total solution for fresh water shortage, required cooling, and high peak power demand. ITES is a well known technology for shifting the electricity demand of cooling systems from peak hours to off-peak hours and desalination by freezing is a less known desalination system which is based on the fact that the ice crystals are pure and by freezing raw water and melting resulted ice crystals, pure water will be produced. These two systems have some common processes and equations and this thesis shows that by combining them the resulted PCWCC could be more efficient than each of them. In this thesis, the thermodynamic equations and efficiencies of each PCWCC sub-systems are analyzed and the resulted data are used in finding thermodynamics of PCWCC itself. Also, by using reMIND software, which uses Cplex to find the best combinations of input/output and related processes, the cost of produced fresh water and cooling from PCWCC is compared with total cost of fresh water and cooling produced by each sub-systems of PCWCC in three sample cities all over the world, Kerman, Dubai, and Texas. These cities are chosen since they have similar ambient temperature trend with different electricity and fresh water tariff's. The results show that, the PCWCC is economical where there is a significant electricity price difference between ice charging and ice melting hours, off-peak and peak hours, of the day or when the fresh water price is high compare to electricity price. The results also show that how the revenue from fresh water could cover the used electricity cost and make some income as well.
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48

Allen, Robert William. "The reciprocating joule cycle engine for micro combined heat and power applications." Thesis, University of Plymouth, 2008. http://hdl.handle.net/10026.1/2683.

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Micro CHP has been identified as a means of reducing the carbon dioxide emissions from household energy consumption. Large scale field trials undertaken in the UK, with systems internal to a single dwelling and based on Stirling engines, were disappointing because of the low thermal efficiencies of such engines. Alternative engines/devices with higher thermal efficiencies are currently being evaluated in Japan but such systems are external to the dwelling. The reciprocating Joule cycle engine is proposed as an engine for a micro CHP system because of its potential to be more thermally efficient than a Stirling engine and at least as thermally efficient as an internal combustion engine. Such an engine has not previously been analysed in detail nor is there any information that such an engine has been built and operated, particularly at power output levels below 5 kW. Mathematical modelling of the RJC engine is used to determine power outputs and efficiencies taking into account frictional, thermal and pressure losses. Such modelling indicated an engine with a maximum thermal efficiency of 33% making it suitable for micro CHP applications. When the individual models are combined to model a CHP system, and using the engine exhaust heat to preheat the combustion air, an overall maximum system efficiency of 79% was indicated.
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49

Brossier, Pierre. "Combined analytical and empirical modelling of power losses in rolling element bearings." Thesis, Lyon, 2020. http://www.theses.fr/2020LYSEI081.

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Le développement de l’industrie du transport conduit la conception de transmissions mécaniques de puissance toujours plus légères et efficientes. Les composants de ces transmissions doivent supporter des efforts transmis dans des environnements de plus en plus restreints. Du fait que les carters soient devenus de plus en plus compacts, les systèmes de refroidissement se sont aussi complexifiés. C’est dans ce contexte que les paliers à roulement, plus communément appelés roulements, doivent produire moins de chaleur, opérer dans des espaces plus proches des engrènements, tout en ayant des durées de vie plus grandes. Le calcul des pertes énergétiques des roulements est essentiel pour quantifier la quantité d’huile à injecter pour refroidir ces composants. L’objectif de cette étude est donc de fournir des outils pour modéliser les pertes dans les roulements et leur comportement thermique. Dans un premier temps, une analyse bibliographique a été menée sur les pertes de puissance dans les roulements, incluant des modèles locaux et globaux de pertes de puissance. Un banc d’essais dédié a été utilisé afin d’analyser les puissances dissipées et la thermique de roulements à billes à gorge profonde. Les influences de la vitesse de rotation, du chargement, de la température d’injection, du débit d’huile injecté, des techniques de lubrification ont été examinées. Les modèles globaux précédemment investigués ont été comparés aux données expérimentales. Enfin, un modèle thermique a été développé pour comprendre l’influence des transferts de chaleur dans les pertes de puissance générées par les roulements. Des comparaisons entre différentes lubrifications et différentes géométries ont été faites. Une nouvelle formule du couple résistif a été proposée pour mieux prendre en compte la géométrie du roulement considéré<br>The development of the transport industry has led to design lighter and more efficient transmission systems. The components within these transmissions have to withstand the transmitted loads in closer environments. As the housing has become more compact than ever, the cooling system has also become more complex. In that context, Rolling Element Bearings (REBs) are required to produce less heat, to work closer to the gear meshes while having higher life-expectancies. The calculation of REB power loss is essential to quantity the amount of injected oil to cool off these components. This study therefore aims at providing tools to model REB power loss and their thermal behaviour. As a first step, a bibliographical survey was conducted on REB power losses, including local and global models. A dedicated test rig has been used to analyse the power losses and the thermal behaviour of Deep Groove Ball Bearings. The influence of rotational speed, load, oil injection temperature, oil flow rate and lubrication design has been investigated. The above-mentioned global models have been compared to the experimental data. Finally, a REB thermal model has been developed in order to understand the influence of heat-transfer within REBs on power losses. Comparisons between different lubrication designs and between different geometries have been done. A new formulation to better take into account the REB geometry in the global models has been proposed
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Maghsoudloo, Esmaeel, and Esmaeel Maghsoudloo. "Wireless power transfer for combined sensing and stimulation in implantable biomedical devices." Doctoral thesis, Université Laval, 2018. http://hdl.handle.net/20.500.11794/33348.

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Actuellement, il existe une forte demande de Headstage et de microsystèmes intégrés implantables pour étudier l’activité cérébrale de souris de laboratoire en mouvement libre. De tels dispositifs peuvent s’interfacer avec le système nerveux central dans les paradigmes électriques et optiques pour stimuler et surveiller les circuits neuronaux, ce qui est essentiel pour découvrir de nouveaux médicaments et thérapies contre des troubles neurologiques comme l’épilepsie, la dépression et la maladie de Parkinson. Puisque les systèmes implantables ne peuvent pas utiliser une batterie ayant une grande capacité en tant que source d’énergie primaire dans des expériences à long terme, la consommation d’énergie du dispositif implantable est l’un des principaux défis de ces conceptions. La première partie de cette recherche comprend notre proposition de la solution pour diminuer la consommation d’énergie des microcircuits implantables. Nous proposons un nouveau circuit de décalage de niveau qui convertit les niveaux de signaux sub-seuils en niveaux ultra-bas à haute vitesse en utilisant une très faible puissance et une petite zone de silicium, ce qui le rend idéal pour les applications de faible puissance. Le circuit proposé introduit une nouvelle topologie de décaleur de niveau de tension utilisant un condensateur de décalage de niveau pour augmenter la plage de tensions de conversion, tout en réduisant considérablement le retard de conversion. Le circuit proposé atteint un délai de propagation plus court et une zone de silicium plus petite pour une fréquence de fonctionnement et une consommation d’énergie donnée par rapport à d’autres solutions de circuit. Les résultats de mesure sont présentés pour le circuit proposé fabriqué dans un processus CMOS TSMC de 0,18- mm. Le circuit présenté peut convertir une large gamme de tensions d’entrée de 330 mV à 1,8 V et fonctionner sur une plage de fréquence de 100 Hz à 100 MHz. Il a un délai de propagation de 29 ns et une consommation d’énergie de 61,5 nW pour les signaux d’entrée de 0,4 V, à une fréquence de 500 kHz, surpassant les conceptions précédentes. La deuxième partie de cette recherche comprend nos systèmes de transfert d’énergie sans fil proposé pour les applications optogénétiques. L’optogénétique est la combinaison de la méthode génétique et optique d’excitation, d’enregistrement et de contrôle des neurones biologiques. Ce système combine plusieurs technologies telles que les MEMS et la microélectronique pour collecter et transmettre les signaux neuronaux et activer un stimulateur optique via une liaison sans fil. Puisque les stimulateurs optiques consomment plus de puissance que les stimulateurs électriques, l’interface utilise la transmission de puissance par induction en utilisant des moyens innovants au lieu de la batterie avec la petite capacité comme source d’énergie.<br>Actuellement, il existe une forte demande de Headstage et de microsystèmes intégrés implantables pour étudier l’activité cérébrale de souris de laboratoire en mouvement libre. De tels dispositifs peuvent s’interfacer avec le système nerveux central dans les paradigmes électriques et optiques pour stimuler et surveiller les circuits neuronaux, ce qui est essentiel pour découvrir de nouveaux médicaments et thérapies contre des troubles neurologiques comme l’épilepsie, la dépression et la maladie de Parkinson. Puisque les systèmes implantables ne peuvent pas utiliser une batterie ayant une grande capacité en tant que source d’énergie primaire dans des expériences à long terme, la consommation d’énergie du dispositif implantable est l’un des principaux défis de ces conceptions. La première partie de cette recherche comprend notre proposition de la solution pour diminuer la consommation d’énergie des microcircuits implantables. Nous proposons un nouveau circuit de décalage de niveau qui convertit les niveaux de signaux sub-seuils en niveaux ultra-bas à haute vitesse en utilisant une très faible puissance et une petite zone de silicium, ce qui le rend idéal pour les applications de faible puissance. Le circuit proposé introduit une nouvelle topologie de décaleur de niveau de tension utilisant un condensateur de décalage de niveau pour augmenter la plage de tensions de conversion, tout en réduisant considérablement le retard de conversion. Le circuit proposé atteint un délai de propagation plus court et une zone de silicium plus petite pour une fréquence de fonctionnement et une consommation d’énergie donnée par rapport à d’autres solutions de circuit. Les résultats de mesure sont présentés pour le circuit proposé fabriqué dans un processus CMOS TSMC de 0,18- mm. Le circuit présenté peut convertir une large gamme de tensions d’entrée de 330 mV à 1,8 V et fonctionner sur une plage de fréquence de 100 Hz à 100 MHz. Il a un délai de propagation de 29 ns et une consommation d’énergie de 61,5 nW pour les signaux d’entrée de 0,4 V, à une fréquence de 500 kHz, surpassant les conceptions précédentes. La deuxième partie de cette recherche comprend nos systèmes de transfert d’énergie sans fil proposé pour les applications optogénétiques. L’optogénétique est la combinaison de la méthode génétique et optique d’excitation, d’enregistrement et de contrôle des neurones biologiques. Ce système combine plusieurs technologies telles que les MEMS et la microélectronique pour collecter et transmettre les signaux neuronaux et activer un stimulateur optique via une liaison sans fil. Puisque les stimulateurs optiques consomment plus de puissance que les stimulateurs électriques, l’interface utilise la transmission de puissance par induction en utilisant des moyens innovants au lieu de la batterie avec la petite capacité comme source d’énergie.<br>Notre première contribution dans la deuxième partie fournit un système de cage domestique intelligent basé sur des barrettes multi-bobines superposées à travers un récepteur multicellulaire implantable mince de taille 1×1 cm2, implanté sous le cuir chevelu d’une souris de laboratoire, et unité de gestion de l’alimentation intégrée. Ce système inductif est conçu pour fournir jusqu’à 35,5 mW de puissance délivrée à un émetteur-récepteur full duplex de faible puissance entièrement intégré pour prendre en charge des implants neuronaux à haute densité et bidirectionnels. L’émetteur (TX) utilise une bande ultra-large à impulsions radio basée sur des approches de combinaison, et le récepteur (RX) utilise une topologie à bande étroite à incrémentation de 2,4 GHz. L’émetteur-récepteur proposé fournit un débit de données de liaison montante TX à 500 Mbits/s double et un débit de données de liaison descendante RX à 100 Mbits/s, et est entièrement intégré dans un processus CMOS TSMC de 0,18-mm d’une taille totale de 0,8 mm2 . La puissance peut être délivrée à partir d’un signal de porteuse de 13,56-MHz avec une efficacité globale de transfert de puissance supérieure à 5% sur une distance de séparation allant de 3 cm à 5 cm. Notre deuxième contribution dans les systèmes de collecte d’énergie porte sur la conception et la mise en oeuvre d’une cage domestique de transmission de puissance sans fil (WPT) pour une plate-forme de neurosciences entièrement sans fil afin de permettre des expériences optogénétiques ininterrompues avec des rongeurs de laboratoire vivants. La cage domestique WPT utilise un nouveau réseau hybride de transmetteurs de puissance (TX) et des résonateurs multi-bobines segmentés pour atteindre une efficacité de transmission de puissance élevée (PTE) et délivrer une puissance élevée sur des distances aussi élevées que 20 cm. Le récepteur de puissance à bobines multiples (RX) utilise une bobine RX d’un diamètre de 1 cm et une bobine de résonateur d’un diamètre de 1,5 cm. L’efficacité moyenne du transfert de puissance WPT est de 29, 4%, à une distance nominale de 7 cm, pour une fréquence porteuse de 13,56 MHz. Il a des PTE maximum et minimum de 50% et 12% le long de l’axe Z et peut délivrer une puissance constante de 74 mW pour alimenter le headstage neuronal miniature. En outre, un dispositif implantable intégré dans un processus CMOS TSMC de 0,18-mm a été conçu et introduit qui comprend 64 canaux d’enregistrement, 16 canaux de stimulation optique, capteur de température, émetteur-récepteur et unité de gestion de l’alimentation (PMU). Ce circuit est alimenté à l’intérieur de la cage du WPT à l’aide d’une bobine réceptrice d’un diamètre de 1,5 cm pour montrer les performances du circuit PMU. Deux tensions régulées de 1,8 V et 1 V fournissent 79 mW de puissance pour tout le système sur une puce. Notre dernière contribution est un système WPT insensible aux désalignements angulaires pour alimenter un headstage pour des applications optogénétiques qui a été précédemment proposé par le Laboratoire de Microsystèmes Biomédicaux (BioML-UL) à ULAVAL. Ce système est la version étendue de notre deuxième contribution aux systèmes de collecte d’énergie.Dans la version mise à jour, un récepteur de puissance multi-bobines utilise une bobine RX d’un diamètre de 1,0 cm et une nouvelle bobine de résonateur fendu d’un diamètre de 1,5 cm, qui résiste aux défauts d’alignement angulaires. Dans cette version qui utilise une cage d’animal plus petite que la dernière version, 4 résonateurs sont utilisés côté TX. De plus, grâce à la forme et à la position de la bobine de répéteur L3 du côté du récepteur, la liaison résonnante hybride présentée peut correctement alimenter la tête sans interruption causée par le désalignement angulaire dans toute la cage de la maison. Chaque 3 tours du répéteur RX a été enveloppé avec un diamètre de 1,5 cm, sous différents angles par rapport à la bobine réceptrice. Les résultats de mesure montrent un PTE maximum et minimum de 53 % et 15 %. La méthode proposée peut fournir une puissance constante de 82 mW pour alimenter le petit headstage neural pour les applications optogénétiques. De plus, dans cette version, la performance du système est démontrée dans une expérience in-vivo avec une souris ChR2 en mouvement libre qui est la première expérience optogénétique sans fil et sans batterie rapportée avec enregistrement électrophysiologique simultané et stimulation optogénétique. L’activité électrophysiologique a été enregistrée après une stimulation optogénétique dans le Cortex Cingulaire Antérieur (CAC) de la souris.<br>Notre première contribution dans la deuxième partie fournit un système de cage domestique intelligent basé sur des barrettes multi-bobines superposées à travers un récepteur multicellulaire implantable mince de taille 1×1 cm2, implanté sous le cuir chevelu d’une souris de laboratoire, et unité de gestion de l’alimentation intégrée. Ce système inductif est conçu pour fournir jusqu’à 35,5 mW de puissance délivrée à un émetteur-récepteur full duplex de faible puissance entièrement intégré pour prendre en charge des implants neuronaux à haute densité et bidirectionnels. L’émetteur (TX) utilise une bande ultra-large à impulsions radio basée sur des approches de combinaison, et le récepteur (RX) utilise une topologie à bande étroite à incrémentation de 2,4 GHz. L’émetteur-récepteur proposé fournit un débit de données de liaison montante TX à 500 Mbits/s double et un débit de données de liaison descendante RX à 100 Mbits/s, et est entièrement intégré dans un processus CMOS TSMC de 0,18-mm d’une taille totale de 0,8 mm2 . La puissance peut être délivrée à partir d’un signal de porteuse de 13,56-MHz avec une efficacité globale de transfert de puissance supérieure à 5% sur une distance de séparation allant de 3 cm à 5 cm. Notre deuxième contribution dans les systèmes de collecte d’énergie porte sur la conception et la mise en oeuvre d’une cage domestique de transmission de puissance sans fil (WPT) pour une plate-forme de neurosciences entièrement sans fil afin de permettre des expériences optogénétiques ininterrompues avec des rongeurs de laboratoire vivants. La cage domestique WPT utilise un nouveau réseau hybride de transmetteurs de puissance (TX) et des résonateurs multi-bobines segmentés pour atteindre une efficacité de transmission de puissance élevée (PTE) et délivrer une puissance élevée sur des distances aussi élevées que 20 cm. Le récepteur de puissance à bobines multiples (RX) utilise une bobine RX d’un diamètre de 1 cm et une bobine de résonateur d’un diamètre de 1,5 cm. L’efficacité moyenne du transfert de puissance WPT est de 29, 4%, à une distance nominale de 7 cm, pour une fréquence porteuse de 13,56 MHz. Il a des PTE maximum et minimum de 50% et 12% le long de l’axe Z et peut délivrer une puissance constante de 74 mW pour alimenter le headstage neuronal miniature. En outre, un dispositif implantable intégré dans un processus CMOS TSMC de 0,18-mm a été conçu et introduit qui comprend 64 canaux d’enregistrement, 16 canaux de stimulation optique, capteur de température, émetteur-récepteur et unité de gestion de l’alimentation (PMU). Ce circuit est alimenté à l’intérieur de la cage du WPT à l’aide d’une bobine réceptrice d’un diamètre de 1,5 cm pour montrer les performances du circuit PMU. Deux tensions régulées de 1,8 V et 1 V fournissent 79 mW de puissance pour tout le système sur une puce. Notre dernière contribution est un système WPT insensible aux désalignements angulaires pour alimenter un headstage pour des applications optogénétiques qui a été précédemment proposé par le Laboratoire de Microsystèmes Biomédicaux (BioML-UL) à ULAVAL. Ce système est la version étendue de notre deuxième contribution aux systèmes de collecte d’énergie.Dans la version mise à jour, un récepteur de puissance multi-bobines utilise une bobine RX d’un diamètre de 1,0 cm et une nouvelle bobine de résonateur fendu d’un diamètre de 1,5 cm, qui résiste aux défauts d’alignement angulaires. Dans cette version qui utilise une cage d’animal plus petite que la dernière version, 4 résonateurs sont utilisés côté TX. De plus, grâce à la forme et à la position de la bobine de répéteur L3 du côté du récepteur, la liaison résonnante hybride présentée peut correctement alimenter la tête sans interruption causée par le désalignement angulaire dans toute la cage de la maison. Chaque 3 tours du répéteur RX a été enveloppé avec un diamètre de 1,5 cm, sous différents angles par rapport à la bobine réceptrice. Les résultats de mesure montrent un PTE maximum et minimum de 53 % et 15 %. La méthode proposée peut fournir une puissance constante de 82 mW pour alimenter le petit headstage neural pour les applications optogénétiques. De plus, dans cette version, la performance du système est démontrée dans une expérience in-vivo avec une souris ChR2 en mouvement libre qui est la première expérience optogénétique sans fil et sans batterie rapportée avec enregistrement électrophysiologique simultané et stimulation optogénétique. L’activité électrophysiologique a été enregistrée après une stimulation optogénétique dans le Cortex Cingulaire Antérieur (CAC) de la souris.<br>Our first contribution in the second part provides a smart home-cage system based on overlapped multi-coil arrays through a thin implantable multi-coil receiver of 1×1 cm2 of size, implantable bellow the scalp of a laboratory mouse, and integrated power management circuits. This inductive system is designed to deliver up to 35.5 mW of power delivered to a fully-integrated, low-power full-duplex transceiver to support high-density and bidirectional neural implants. The transmitter (TX) uses impulse radio ultra-wideband based on an edge combining approach, and the receiver (RX) uses a 2.4- GHz on-off keying narrow band topology. The proposed transceiver provides dual-band 500-Mbps TX uplink data rate and 100-Mbps RX downlink data rate, and it is fully integrated into 0.18-mm TSMC CMOS process within a total size of 0.8 mm2. The power can be delivered from a 13.56-MHz carrier signal with an overall power transfer efficiency above 5% across a separation distance ranging from 3 cm to 5 cm. Our second contribution in power-harvesting systems deals with designing and implementation of a WPT home-cage for a fully wireless neuroscience platform for enabling uninterrupted optogenetic experiments with live laboratory rodents. The WPT home-cage uses a new hybrid parallel power transmitter (TX) coil array and segmented multi-coil resonators to achieve high power transmission efficiency (PTE) and deliver high power across distances as high as 20 cm. The multi-coil power receiver (RX) uses an RX coil with a diameter of 1 cm and a resonator coil with a diameter of 1.5 cm. The WPT home-cage average power transfer efficiency is 29.4%, at a nominal distance of 7 cm, for a power carrier frequency of 13.56-MHz. It has maximum and minimum PTE of 50% and 12% along the Z axis and can deliver a constant power of 74 mW to supply the miniature neural headstage. Also, an implantable device integrated into a 0.18-mm TSMC CMOS process has been designed and introduced which includes 64 recording channels, 16 optical stimulation channels, temperature sensor, transceiver, and power management unit (PMU). This circuit powered up inside the WPT home-cage using receiver coil with a diameter of 1.5 cm to show the performance of the PMU circuit. Two regulated voltages of 1.8 V and 1 V provide 79 mW of power for all the system on a chip. Our last contribution is an angular misalignment insensitive WPT system to power up a headstage which has been previously proposed by the Biomedical Microsystems Laboratory (BioML-UL) at ULAVAL for optogenetic applications. This system is the extended version of our second contribution in power-harvesting systems. In the updated version a multi-coil power receiver uses an RX coil with a diameter of 1.0 cm and a new split resonator coil with a diameter of 1.5 cm, which is robust against angular misalignment. In this version which is using a smaller animal home-cage than the last version, 4 resonators are used on the TX side. Also, thanks to the shape and position of the repeater coil of L3 on the receiver side, the presented hybrid resonant link can properly power up the headstage without interruption caused by the angular misalignment all over the home-cage. Each 3 turns of the RX repeater has been wrapped up with a diameter of 1.5 cm, in different angles compared to the receiver coil. Measurement results show a maximum and minimum PTE of 53 % and 15 %. The proposed method can deliver a constant power of 82 mW to supply the small neural headstage for the optogenetic applications. Additionally, in this version, the performance of the system is demonstrated within an in-vivo experiment with a freely moving ChR2 mouse which is the first fully wireless and batteryless optogenetic experiment reported with simultaneous electrophysiological recording and optogenetic stimulation. Electrophysiological activity was recorded after delivering optogenetic stimulation in the Anterior Cingulate Cortex (ACC) of the mouse.<br>Our first contribution in the second part provides a smart home-cage system based on overlapped multi-coil arrays through a thin implantable multi-coil receiver of 1×1 cm2 of size, implantable bellow the scalp of a laboratory mouse, and integrated power management circuits. This inductive system is designed to deliver up to 35.5 mW of power delivered to a fully-integrated, low-power full-duplex transceiver to support high-density and bidirectional neural implants. The transmitter (TX) uses impulse radio ultra-wideband based on an edge combining approach, and the receiver (RX) uses a 2.4- GHz on-off keying narrow band topology. The proposed transceiver provides dual-band 500-Mbps TX uplink data rate and 100-Mbps RX downlink data rate, and it is fully integrated into 0.18-mm TSMC CMOS process within a total size of 0.8 mm2. The power can be delivered from a 13.56-MHz carrier signal with an overall power transfer efficiency above 5% across a separation distance ranging from 3 cm to 5 cm. Our second contribution in power-harvesting systems deals with designing and implementation of a WPT home-cage for a fully wireless neuroscience platform for enabling uninterrupted optogenetic experiments with live laboratory rodents. The WPT home-cage uses a new hybrid parallel power transmitter (TX) coil array and segmented multi-coil resonators to achieve high power transmission efficiency (PTE) and deliver high power across distances as high as 20 cm. The multi-coil power receiver (RX) uses an RX coil with a diameter of 1 cm and a resonator coil with a diameter of 1.5 cm. The WPT home-cage average power transfer efficiency is 29.4%, at a nominal distance of 7 cm, for a power carrier frequency of 13.56-MHz. It has maximum and minimum PTE of 50% and 12% along the Z axis and can deliver a constant power of 74 mW to supply the miniature neural headstage. Also, an implantable device integrated into a 0.18-mm TSMC CMOS process has been designed and introduced which includes 64 recording channels, 16 optical stimulation channels, temperature sensor, transceiver, and power management unit (PMU). This circuit powered up inside the WPT home-cage using receiver coil with a diameter of 1.5 cm to show the performance of the PMU circuit. Two regulated voltages of 1.8 V and 1 V provide 79 mW of power for all the system on a chip. Our last contribution is an angular misalignment insensitive WPT system to power up a headstage which has been previously proposed by the Biomedical Microsystems Laboratory (BioML-UL) at ULAVAL for optogenetic applications. This system is the extended version of our second contribution in power-harvesting systems. In the updated version a multi-coil power receiver uses an RX coil with a diameter of 1.0 cm and a new split resonator coil with a diameter of 1.5 cm, which is robust against angular misalignment. In this version which is using a smaller animal home-cage than the last version, 4 resonators are used on the TX side. Also, thanks to the shape and position of the repeater coil of L3 on the receiver side, the presented hybrid resonant link can properly power up the headstage without interruption caused by the angular misalignment all over the home-cage. Each 3 turns of the RX repeater has been wrapped up with a diameter of 1.5 cm, in different angles compared to the receiver coil. Measurement results show a maximum and minimum PTE of 53 % and 15 %. The proposed method can deliver a constant power of 82 mW to supply the small neural headstage for the optogenetic applications. Additionally, in this version, the performance of the system is demonstrated within an in-vivo experiment with a freely moving ChR2 mouse which is the first fully wireless and batteryless optogenetic experiment reported with simultaneous electrophysiological recording and optogenetic stimulation. Electrophysiological activity was recorded after delivering optogenetic stimulation in the Anterior Cingulate Cortex (ACC) of the mouse.<br>Currently, there is a high demand for Headstage and implantable integrated microsystems to study the brain activity of freely moving laboratory mice. Such devices can interface with the central nervous system in both electrical and optical paradigms for stimulating and monitoring neural circuits, which is critical to discover new drugs and therapies against neurological disorders like epilepsy, depression, and Parkinson’s disease. Since the implantable systems cannot use a battery with a large capacity as a primary source of energy in long-term experiments, the power consumption of the implantable device is one of the leading challenges of these designs. The first part of this research includes our proposed solution for decreasing the power consumption of the implantable microcircuits. We propose a novel level shifter circuit which converting subthreshold signal levels to super-threshold signal levels at high-speed using ultra low power and a small silicon area, making it well-suited for low-power applications such as wireless sensor networks and implantable medical devices. The proposed circuit introduces a new voltage level shifter topology employing a level-shifting capacitor to increase the range of conversion voltages, while significantly reducing the conversion delay. The proposed circuit achieves a shorter propagation delay and a smaller silicon area for a given operating frequency and power consumption compared to other circuit solutions. Measurement results are presented for the proposed circuit fabricated in a 0.18-mm TSMC CMOS process. The presented circuit can convert a wide range of the input voltages from 330 mV to 1.8 V, and operate over a frequency range of 100-Hz to 100-MHz. It has a propagation delay of 29 ns, and power consumption of 61.5 nW for input signals 0.4 V, at a frequency of 500-kHz, outperforming previous designs. The second part of this research includes our proposed wireless power transfer systems for optogenetic applications. Optogenetics is the combination of the genetic and optical method of excitation, recording, and control of the biological neurons. This system combines multiple technologies such as MEMS and microelectronics to collect and transmit the neuronal signals and to activate an optical stimulator through a wireless link. Since optical stimulators consume more power than electrical stimulators, the interface employs induction power transmission using innovative means instead of the battery with the small capacity as a power source.<br>Currently, there is a high demand for Headstage and implantable integrated microsystems to study the brain activity of freely moving laboratory mice. Such devices can interface with the central nervous system in both electrical and optical paradigms for stimulating and monitoring neural circuits, which is critical to discover new drugs and therapies against neurological disorders like epilepsy, depression, and Parkinson’s disease. Since the implantable systems cannot use a battery with a large capacity as a primary source of energy in long-term experiments, the power consumption of the implantable device is one of the leading challenges of these designs. The first part of this research includes our proposed solution for decreasing the power consumption of the implantable microcircuits. We propose a novel level shifter circuit which converting subthreshold signal levels to super-threshold signal levels at high-speed using ultra low power and a small silicon area, making it well-suited for low-power applications such as wireless sensor networks and implantable medical devices. The proposed circuit introduces a new voltage level shifter topology employing a level-shifting capacitor to increase the range of conversion voltages, while significantly reducing the conversion delay. The proposed circuit achieves a shorter propagation delay and a smaller silicon area for a given operating frequency and power consumption compared to other circuit solutions. Measurement results are presented for the proposed circuit fabricated in a 0.18-mm TSMC CMOS process. The presented circuit can convert a wide range of the input voltages from 330 mV to 1.8 V, and operate over a frequency range of 100-Hz to 100-MHz. It has a propagation delay of 29 ns, and power consumption of 61.5 nW for input signals 0.4 V, at a frequency of 500-kHz, outperforming previous designs. The second part of this research includes our proposed wireless power transfer systems for optogenetic applications. Optogenetics is the combination of the genetic and optical method of excitation, recording, and control of the biological neurons. This system combines multiple technologies such as MEMS and microelectronics to collect and transmit the neuronal signals and to activate an optical stimulator through a wireless link. Since optical stimulators consume more power than electrical stimulators, the interface employs induction power transmission using innovative means instead of the battery with the small capacity as a power source.
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