To see the other types of publications on this topic, follow the link: Low voltage power distribution.
Dissertations / Theses on the topic 'Low voltage power distribution'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic 'Low voltage power distribution.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
Youssef, Rida Daniel. "Interactive graphic design of low voltage distribution systems." Thesis, University of Manchester, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.260933.
Full text
2
Salomonsson, Daniel. "Modeling, Control and Protection of Low-Voltage DC Microgrids." Doctoral thesis, Stockholm : Elektriska energisystem, Electric Power Systems, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-4666.
Full text
3
Hölling, Matthias. "Adaptive current and voltage measurement device for low voltage distribution in power nets /." [S.l.] : [s.n.], 2000. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=13985.
Full text
4
Squarzoni, Nicolò. "Metrological Characterization of a Low Power Voltage Transformer Embedded in Distribution Switchgears." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2017.
Find full textAbstract:
This paper presents an experimental campaign carried out on the Accusense voltage sensors for medium
voltage distribution grids, developed in partnership with Altea Solutions.
The project involves G&W Electric Company, switchgear manufacturer, Altea Solutions, sensor
manufacturer, and the University of Bologna.
The entire project has been carried out by the senior graduate power engineering student Nicolo’
Squarzoni, under supervision of Nenad Uzelac and Blair S. Kerr from G&W Electric side and under
supervision of Prof. Lorenzo Peretto from both Altea Solutions and University of Bologna side.
The aim of the project was to design and build highly accurate measuring systems in order to carry out
accuracy tests on multiple samples of Accusense active and passive sensors under different operating
conditions, eventually collecting results for comparison and marketing purposes.
5
Li, Yun. "Voltage balancing on three-phase low voltage feeder." Thesis, University of Manchester, 2015. https://www.research.manchester.ac.uk/portal/en/theses/voltage-balancing-on-threephase-low-voltage-feeder(4320ec9a-f287-4e83-86fd-c8e29e8d49f4).html.
Full textAbstract:
Voltage imbalance in low voltage (LV) networks is expected to deteriorate as low carbon technologies, e.g. electric vehicles (EVs) and heat pumps (HPs) are increasingly deployed. The new electrical demand attributable to EVs and HPs would increase the voltage magnitude variation, increasing the possibility of voltages moving outside the statutory LV magnitude limits. Moreover, the single-phase nature of EVs and HPs, which will be connected via a single-phase 'line & neutral' cable to a 3-phase four-wire LV mains cable buried beneath the street, further entangles this voltage management problem; the non-balanced voltage variations in the three phases boost the levels of voltage imbalance. Excessive voltage imbalance and magnitude variation need to be mitigated to limit their adverse effects on the electric network and connected plant. The voltage imbalance in LV networks is conventionally reduced by reinforcing the network, generally at a high cost. Some modern methods for voltage imbalance mitigation have been introduced in recent years. The power electronic converter based methods are inadequate due to the generation of harmonics, significant power losses and short lifetime. Besides, automatic supply phase selection and smart EV charging rely on an advanced smart communication system, which currently is not available. This project aims to develop alternative solutions that mitigate the voltage imbalance seen in LV networks. A voltage balancing method based on Scott transformer (ST) is proposed. This method does not generate harmonics and is independent of the smart communication system. Computer simulations demonstrated the proposed method is able to convert a non-balanced 3-phase voltage into a balanced 3-phase voltage at either a point on the LV feeder or a 3-phase load supply point with the predefined voltage magnitude. Besides, a physical voltage balancing system was created based on the proposed method and it was tested in an LV network in the laboratory. The test results show the balancing system is capable of maintaining a low level of voltage imbalance on the LV feeder by rapidly compensating for the voltage rises and sags caused by single-phase load variations. This voltage balancing method is a potential solution for the network utilities to accommodate the significant penetration of low carbon technologies without breaching the network voltage limits. The impact of EVs and HPs on the LV network voltages is investigated based on a Monte Carlo (MC) simulation platform, which comprises a statistical model of EV charging demand, profiles generators of residential and HP electrical demand, and a distribution network model. The MC simulation indicates the impact of EVs and HPs is related to their distribution; when more than 21EVs and 13HPs are non-evenly distributed on a 96-customer LV feeder, the voltage limits are likely to be violated. Moreover, the effectiveness of the ST based voltage balancing method and the demand response based TOU tariff, implemented either alone or together, in mitigating the impact of EVs and HPs is investigated based on the established MC simulation platform. The results indicate the ST based balancing method alone is able to completely mitigate the voltage limit violations regardless of the penetration levels of EVs and HPs. Moreover, using both of the two investigated methods further enhances the balancing effectiveness of the ST based voltage balancing method.
6
Bernal, Alzate Efrain [Verfasser]. "Central reactive power control for smart low-voltage distribution grids / Efrain Bernal Alzate." Ulm : Universität Ulm, 2017. http://d-nb.info/1148551085/34.
Full text
7
Chen, Fang. "Control of DC Power Distribution Systems and Low-Voltage Grid-Interface Converter Design." Diss., Virginia Tech, 2017. http://hdl.handle.net/10919/77532.
Full textAbstract:
DC power distribution has gained popularity in sustainable buildings, renewable energy utilization, transportation electrification and high-efficiency data centers. This dissertation focuses on two aspects of facilitating the application of dc systems: (a) system-level control to improve load sharing, voltage regulation and efficiency; (b) design of a high-efficiency interface converter to connect dc microgrids with the existing low-voltage ac distributions, with a special focus on common-mode (CM) voltage attenuation.
Droop control has been used in dc microgrids to share loads among multiple sources. However, line resistance and sensor discrepancy deteriorate the performance. The quantitative relation between the droop voltage range and the load sharing accuracy is derived to help create droop design guidelines. DC system designers can use the guidelines to choose the minimum droop voltage range and guarantee that the sharing error is within a defined range even under the worst cases.
A nonlinear droop method is proposed to improve the performance of droop control. The droop resistance is a function of the output current and increases when the output current increases. Experiments demonstrate that the nonlinear droop achieves better load sharing under heavy load and tighter bus voltage regulation. The control needs only local information, so the advantages of droop control are preserved. The output impedances of the droop-controlled power converters are also modeled and measured for the system stability analysis.
Communication-based control is developed to further improve the performance of dc microgrids. A generic dc microgrid is modeled and the static power flow is solved. A secondary control system is presented to achieve the benefits of restored bus voltage, enhanced load sharing and high system efficiency. The considered method only needs the information from its adjacent node; hence system expendability is guaranteed.
A high-efficiency two-stage single-phase ac-dc converter is designed to connect a 380 V bipolar dc microgrid with a 240 V split-phase single-phase ac system. The converter efficiencies using different two-level and three-level topologies with state-of-the-art semiconductor devices are compared, based on which a two-level interleaved topology using silicon carbide (SiC) MOSFETs is chosen. The volt-second applied on each inductive component is analyzed and the interleaving angles are optimized. A 10 kW converter prototype is built and achieves an efficiency higher than 97% for the first time.
An active CM duty cycle injection method is proposed to control the dc and low-frequency CM voltage for grounded systems interconnected with power converters. Experiments with resistive and constant power loads in rectification and regeneration modes validate the performance and stability of the control method. The dc bus voltages are rendered symmetric with respect to ground, and the leakage current is reduced. The control method is generalized to three-phase ac-dc converters for larger power systems.Ph. D.
8
Tong, Yajian. "Multiple-input multiple-output converters for future low-voltage DC power distribution architectures." Thesis, University of British Columbia, 2015. http://hdl.handle.net/2429/52780.
Full textAbstract:
Multiple-input multiple-output (MIMO) converters have been identified as a cost-effective approach for energy harvesting and dispatching in hybrid power systems such as those envisioned in future smart homes and DC microgrids. Compared with relatively complex set-up of single-input single-output (SISO) converters linked at a common DC bus to exchange power, the MIMO converters possess promising features of fewer components, higher power density, and centralized control. This thesis addresses various issues regarding the development of MIMO converters. Both non-isolated and isolated MIMO converter topologies are proposed. Steady-state analysis and dynamic modeling of MIMO non-inverting buck–boost and flyback converters are introduced and presented in detail. Specific switching strategies are proposed and appropriate control algorithms are presented to enable power budgeting between diverse sources and loads in addition to regulating output voltages. Furthermore, a simple method is put forward for deriving the non-isolated MIMO converters with DC-link inductor (DLI) and DC-link capacitor (DLC). Based on a basic structure, a set of rules is listed for the synthesis of MIMO converters. Using the time-sharing concept, multiple sources provide energy in one period, and multiple loads draw energy in the subsequent period. In the end, general techniques are introduced for extending the SISO converters to their MIMO versions, where parts of the conventional SISO converters are replaced with multiport structures. It is envisioned that MIMO converters presented in this thesis will find their acceptance in the future in various applications with DC distribution, which are becoming increasingly accepted by industry.Applied Science, Faculty of
Electrical and Computer Engineering, Department of
Graduate
9
Navarro, Espinosa Alejandro. "Low carbon technologies in low voltage distribution networks : probabilistic assessment of impacts and solutions." Thesis, University of Manchester, 2015. https://www.research.manchester.ac.uk/portal/en/theses/low-carbon-technologies-in-low-voltage-distribution-networks-probabilistic-assessment-of-impacts-and-solutions(cc5c77df-54fe-4c1c-a599-3bbea8fbd0c1).html.
Full textAbstract:
The main outcome of this research is the development of a Probabilistic Impact Assessment methodology to comprehensively understand the effects of low carbon technologies (LCTs) in low voltage (LV) distribution networks and the potential solutions available to increase their adoption. The adoption of LCTs by domestic customers is an alternative to decreasing carbon emissions. Given that these customers are connected to LV distribution networks, these assets are likely to face the first impacts of LCTs. Thus, to quantify these problems a Monte Carlo-based Probabilistic Impact Assessment methodology is proposed in this Thesis. This methodology embeds the uncertainties related to four LCTs (PV, EHPs, µCHP and EVs). Penetration levels as a percentage of houses with a particular LCT, ranging from 0 to 100% in steps of 10%, are investigated. Five minute time-series profiles and three-phase four-wire LV networks are adopted. Performance metrics related to voltage and congestion are computed for each of the 100 simulations per penetration level. Given the probabilistic nature of the approach, results can be used by decision makers to determine the occurrence of problems according to an acceptable probability of technical issues. To implement the proposed methodology, electrical models of real LV networks and high resolution profiles for loads and LCTs are also developed. Due to the historic passive nature of LV circuits, many Distribution Network Operators (DNOs) have no model for them. In most cases, the information is limited to Geographic Information Systems (GIS) typically produced for asset management purposes and sometimes with connectivity issues. Hence, this Thesis develops a methodology to transform GIS data into suitable computer-based models. In addition, thousands of residential load, PV, µCHP, EHP and EV profiles are created. These daily profiles have a resolution of five minutes. To understand the average behaviour of LCTs and their relationship with load profiles, the average peak demand is calculated for different numbers of loads with and without each LCT.The Probabilistic Impact Assessment methodology is applied over 25 UK LV networks (i.e., 128 feeders) for the four LCTs under analysis. Findings show that about half of the studied feeders are capable of having 100% of the houses with a given LCT. A regression analysis is carried out per LCT, to identify the relationships between the first occurrence of problems and key feeder parameters (length, number of customers, etc.). These results can be translated into lookup tables that can help DNOs produce preliminary and quick estimates of the LCT impacts on a particular feeder without performing detailed studies. To increase the adoption of LCTs in the feeders with problems, four solutions are investigated: feeder reinforcement, three-phase connection of LCTs, loop connection of LV feeders and implementation of OLTCs (on-load tap changers) in LV networks. All these solutions are embedded in the Probabilistic Impact Assessment. The technical and economic benefits of each of the solutions are quantified for the 25 networks implemented.
10
Uriarte, Fabian. "Modeling, Detection, and Localization of High-Impedance Faults In Low-Voltage Distribution Feeders." Thesis, Virginia Tech, 2003. http://hdl.handle.net/10919/30810.
Full textAbstract:
High-impedance faults (HIFs) on distribution feeders are abnormal electrical conditions that cannot be detected by conventional protection schemes. These faults pose a threat on human lives when neighboring objects become in contact with the lineâ s bare and energized conductors. An accurate electrical model for a HIF is implemented to investigate typical patterns in the lineâ s current that allow for the detection of these faults. The occurrence of HIFs is detected with harmonic-current phase analysis and localized with recloser-sectionalizer technology as presented in this work. A sectionalizer algorithm is then presented showing the decision criteria for HIF declaration and shown to discriminate against nominal behavior in distribution feeders of similar harmonic content. Finally, it is shown that the algorithm will not produce a misreading when a current transformer enters saturation.Master of Science
11
Häggblom, Johan, and Jonathan Jerner. "Photovoltaic Power Production and Energy Storage Systems in Low-Voltage Power Grids." Thesis, Linköpings universitet, Fordonssystem, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-156875.
Full textAbstract:
In recent years, photovoltaic (PV) power production have seen an increase and the PV power systems are often located in the distribution grids close to the consumers. Since the distributions grids rarely are designed for power production, investigation of its effects is needed. It is seen in this thesis that PV power production will cause voltages to rise, potentially to levels exceeding the limits that grid owners have to abide by. A model of a distribution grid is developed in MathWorks MATLAB. The model contains a transformer, cables, households, energy storage systems (ESS:s) and photovoltaic power systems. The system is simulated by implementing a numerical Forward Backward Sweep Method, solving for powers, currents and voltages in the grid. PV power systems are added in different configurations along with different configurations of ESS:s. The results are analysed, primarily concerning voltages and voltage limits. It is concluded that addition of PV power production in the distribution grid affects voltages, more or less depending on where in the grid the systems are placed and what peak power they have. It is also concluded that having energy storage systems in the grid, changing the power factor of the inverter for the PV systems or lowering the transformer secondary-side voltage can bring the voltages down.På senare tid har det skett en ökning i antalet solcellsanläggningar som installeras i elnätet och dessa är ofta placerade i distributionsnäten nära hushållen. Eftersom distributionsnäten sällan är dimensionerade för produktion så behöver man utreda effekten av det. I det här arbetet visas det att solcellsproduktion kommer att öka spänningen i elnätet, potentiellt så mycket att de gränser elnätsägarna måste hålla nätet inom överstigs. En modell över lågspänningsnätet skapas i MathWorks MATLAB. Modellen innehåller transformator, kablar, hushåll, energilager och solcellsanläggningar. Systemet simuleras med hjälp av en numerisk Forward Backward Sweep-lösare som beräknar effekter, strömmar och spänningar i elnätet. Solcellanläggningarna placeras ut i elnätet i olika konfigurationer tillsammans med olika konfigurationer av energilager. Resultaten från simuleringarna analyseras främst med avseende på spänningen i elnätet utifrån dess gränser. De slutsatser som dras i arbetet är att solcellsproduktion kommer att påverka spänningen, mycket beroende på var i elnätet anläggningarna placeras och storleken hos dem. Det visas också att energilager, justering av effektfaktor hos solcellsanläggningarna eller en spänningssänkning på transformatorns lågspänningssida kan få ner spänningen i elnätet.
LiTH-ISY-EX--19/5194--SE
12
Gustafsson, Anton. "Case Study of Photovoltaics and Electric Vehicle Charging in a Low-Voltage Distribution Grid." Thesis, Uppsala universitet, Elektricitetslära, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-395972.
Full textAbstract:
This thesis investigates the effects from a grid connection of photovoltaics and electric vehicle charging in a low-voltage distribution grid. The study has taken place on behalf of Norrtälje Energi AB, and the object of study is a customer in one of their rural grids. Due to reported disturbances by the customer, a Magtech Voltage Booster (MVB) was installed at the point of common coupling. To evaluate the situation, three power quality measurements were analysed. Furthermore, a model of the distribution grid was developed in OpenDSS. The main conclusion of this thesis is that the disturbances seems to be caused by temporary voltage drops (below 195.5 V) during charging hours. This situation continues to create problems even though the MVB boosts and balances the voltage. The power quality measurements showed that the voltage unbalance, during charging hours, violated the limit both before and after the MVB-installation. Another significant conclusion in this thesis is that the MVB does not seem to improve the power quality, on the contrary it deteriorates the power quality with regards to rapid voltage change and harmonic content. Furthermore, the OpenDSS-model was able to predict the temporary voltage drops. And the model also resulted in voltage unbalance comparable to the measurements. The model also displayed how the voltage unbalance and harmonic content mitigated to other parts of the grid, and it became clear that it is only the closest neighbour that is in the risk of deteriorated power quality.
13
Bicer, Nazan. "A Current Source Converter Based Statcom For Reactive Power Compensation At Low Voltage." Master's thesis, METU, 2010. http://etd.lib.metu.edu.tr/upload/2/12612007/index.pdf.
Full textAbstract:
This research work is devoted to the analysis, design and development of the Current-Source Converter (CSC) based distribution-type Static Synchronous Compensator (D-STATCOM) for low-voltage applications in reactive-power control in order to achieve i) faster transient response in reactive-power control, ii) lower current harmonic distortion, iii) lower power losses and iv) minimum storage elements in comparison with conventional solutions. The developed CSC-D-STATCOM includes a low-pass input filter and a three phase forced-commutated CSC which is composed of six insulated gate bipolar transistors (IGBT) with built-in series diodes. The analysis and the control of the CSC-D-STATCOM are carried out in dq-synchronous reference frame in order to obtain the reference current waveform which is to be generated by switching the IGBTs at 3kHz with the use of space vector modulation.
14
Heunis, Schalk W. (Schalk Willem). "The analysis and quantifiaction of uncertainty for least life-cost electrical low voltage distribution design." Thesis, Stellenbosch : Stellenbosch University, 2000. http://hdl.handle.net/10019.1/51937.
Full textAbstract:
Dissertation (PhD)--University of Stellenbosch, 2000.ENGLISH ABSTRACT: The purpose of this dissertation is to provide methods for designing and managing low voltage residential feeders. These methods can be applied to the problem of planning residential networks under uncertainty while ensuring least life-cycle costs. By analysing collected load data from various communities in South Africa, a new probabilistic model for representing the load uncertainty of residential consumers was derived. This model uses the beta probability distribution to describe individual consumer loads over a period of time. Methods for combining the loads in linear combinations were used to derive a new probabilistic voltage regulation calculation procedure. This new method is different from previously developed voltage calculation methods in that it can be used to estimate the probable voltage performance of a feeder over a period of time. A simplification of the method is proposed which allows it to be implemented in any commercial spreadsheet program. The new probabilistic load model was also applied to the problem of calculating resistive losses in residential low voltage feeders. A new probabilistic method was formulated and this method can be used to estimate the probable range of resistive loss in a feeder for a period of time. This method is simple enough to implement in a commercial spreadsheet program. Probabilistic information about network and load parameter uncertainty is seldom available and these uncertainties are best modelled using fuzzy numbers. The probabilistic calculation methods cannot represent these uncertainties and only after applying a fuzzy-probabilistic approach can both types of uncertainties be used. This is a significant enhancement to the current methods and ensures that the uncertainty about the calculated results is realistically represented. The specification of load parameters for the methods was significantly simplified following a regression analysis of collected load data from South African communities. By specifying the distribution of the consumption of individual consumers in a community, the other load parameters can be estimated using a set of fitted linear regression equations. This greatly reduces the burden of specifying the load parameters and makes it possible for the proposed calculation methods to be applied to the design of new feeders in practice. The distribution of the consumption of individual consumers can be specified using the average and the standard deviation of the consumptions of individual consumers. Accurate estimates of these parameters can be obtained from sales information and can be used to manage existing networks effectively. Using the sales information with the proposed methods enables more cost-effective upgrades of existing feeders low voltage feeders. The identification of potential problems in existing low voltage networks is also possible if the layout of the feeders in a community is known. The use of the proposed methods is illustrated in step-by-step fashion. Typical input parameters are used and all the required calculations with intermediate results are presented.
AFRIKAANSE OPSOMMING: Die doel van hierdie proefskrif is die daarstelling van residensiële laagspanningsnetwerk ontwerp- en bestuursmetodes. Hierdie metodes kan toegepas word vir die beplanning van residensiële laagspanningsnetwerke waar onsekerheid bestaan oor toekomstige kragverbruik en die spesifikasie van die netwerkparameters. Lasdata, wat versamel is in verskeie Suid Afrikaanse gemeenskappe, is geanaliseer en 'n nuwe probabilistiese modellering van die onsekerheid oor die kragverbruik van residensiële verbruikers is ontwikkel. Gebruik is gemaak van die beta waarskynlikheidsdightheidsfunksie om die tydsgebonde kragverbruik van die verbruikers voor te stel. 'n Nuwe probabilistiese spanningsvalberekeningsmetode is ontwikkel en die metode maak gebruik van liniêre kombinasies van die lasstrome van die verbruikers. Die verskil tussen hierdie metode en bestaande metodes is dat dit die tydsgebonde waarskynlikheid van die spanningsregulasie van 'n kabel kan bereken. 'n Vereenvoudiging van die metode is ook verkry en dit kan in enige kommersiële sigblad geïmplementeer word. Die probabilistiese lasstroommodel is ook gebruik om 'n nuwe probabilistiese energieverliesberekeningsmetode te ontwikkel. Hierdie metode kan gebruik word om die tydsgebonde waarskynlikhede van 'n reeks van moontlike energieverlieswaardes te bereken. Die metode is eenvoudig genoeg om in enige kommersiële sigblad te implementeer. Onsekerheid oor die spesifikasie van die parameters van die nuwe metodes asook die netwerkparameters kan nie met probabilistiese metodes voorgestel word nie, aangesien inligting oor die waarskynlikhede van parameters selde beskikbaar is. Hierdie onsekerhede kan beter voorgestel word deur die gebruik van sogenaamde "fuzzy"-metodes. Die voorgestelde probabilistiese metodes is aangepas om hierdie tipe onsekerhede ook in ag te neem. "Fuzzy-probabilistic" metodes is gebruik vir dié aanpassings en word beskou as 'n noemenswaardige verbetering van die metodes. Die verbeterde metodes verkaf meer realistiese voorstellings van die onsekerheid oor berekende resultate. 'n Statisitiese analise van Suid Afrikaanse lasdata het 'n vereenvoudiging van die spesifisering van die parameters van die nuwe metodes tot gevolg gehad. Die waarskynlikheidsverspreiding van die energieverbruik van huishoudelike verbruikers kan gebruik word om akkurate skattings van die ander parameters te verkry. Hierdie vereenvoudiging het tot gevolg dat die nuwe metodes vir praktiese netwerkontwerp gebruik kan word. Die waarskynlikheidsverpreiding van die energieverbruik van verbuikers is beskikbaar in die vorm van energieverkope en kan gebruik word vir die effektiewe bestuur en opgradering van bestaande netwerke. As die uitleg van die bestaande netwerke in 'n gemeenskap beskikbaar is, kan die inligting wat bevat is in die energieverkope gebruik word om probleme in bestaande netwerke te identifiseer. Al die voorgestelde metodes is stap vir stap uiteengesit met voorbeelde van al die berekeninge met tipiese waardes.
15
Danisman, Batuhan. "Analysis Of Conventional Low Voltage Power Line Communication Methods For Automatic Meter Reading And The Classification And Experimental Verification Of Noise Types For Low Voltage Power Line Communication Network." Master's thesis, METU, 2009. http://etd.lib.metu.edu.tr/upload/12610469/index.pdf.
Full textAbstract:
In this thesis, the conventional low voltage power line communication methods is
investigated in the axis of automated meter reading applications and the classification
and experimental verification of common noise types for low voltage power line
communication network. The investigated system provides the real time transmission
of electricity consumption data recorded by electricity meters, initially to a local
computer via a low voltage line through a low speed PLC (Power Line Carrier)
environment and subsequently to a corporate network through a high speed data
transmission medium. The automated meter system provides a more effective
tracking and data acquisition, a more detailed and vigorous knowledge about
consumer behavior for subscriber assessment in electricity distribution in association
with a brand new management and system supervision concept in electricity
distribution control and management technology. The theoretical studies are
experimentally verified for the Turkish low voltage power infrastructure through
laboratory experiments performed in METU Electrical and Electronics Engineering
Department, Electrical Machines and Drives Laboratory and R&D Laboratories of MAKEL facilities in Hadimkö
y. The single phase voltage of the mains line between the phase and neutral is monitored to exhibit the disturbing effects of various noise sources. The resulting voltage spectrum is logged by using digital data acquisition devices in time and frequency domain. The waveforms are converted to frequency domain using the Fast Fourier Transform (FFT) functions of the MATLAB. The experimental results are compared to the theoretical findings obtained through literature survey.
16
Gutierrez, Lagos Luis Daniel. "Advanced voltage control for energy conservation in distribution networks." Thesis, University of Manchester, 2018. https://www.research.manchester.ac.uk/portal/en/theses/advanced-voltage-control-for-energy-conservation-in-distribution-networks(2718dcf1-f5db-45df-84e2-4890956ba8b1).html.
Full textAbstract:
The increasing awareness on the effect of carbon emissions in our planet has led to several countries to adopt targets for their reduction. One way of contributing to this aim is to use and distribute electricity more efficiently. In this context, Conservation Voltage Reduction (CVR), a well-known technique that takes advantage of the positive correlation between voltage and demand to reduce energy consumption, is gaining renewed interest. This technique saves energy by only reducing customer voltages, without relying on customer actions and, therefore, can be controlled by the Distribution Network Operator (DNO). CVR not only brings benefits to the electricity system by reducing generation requirements (fewer fossil fuel burning and carbon emissions), but also to customers, as energy bill reductions. The extent to which CVR can bring benefits mainly depends on the customers load composition and their voltages. While the former dictates the voltage-demand correlation, the latter constraints the voltage reduction that can be applied without violating statutory limits. Although CVR has been studied for many years, most of the studies neglect the time-varying voltage-demand characteristic of loads and/or do not assess end customer voltages. While these simplifications could be used to estimate CVR benefits for fixed and limited voltage reductions, realistic load and network models are needed to assess the performance of active CVR schemes, where voltages are actively managed to be close to the minimum limit. Moreover, distribution networks have been traditionally designed with limited monitoring and controllability. Therefore, CVR has been typically implemented by adopting conservative voltage reductions from primary substations, for both American and European-style networks. However, as new infrastructure is deployed in European-style LV networks (focus of this work), such as monitoring and on-load tap changers (OLTCs), the opportunity arises to actively manage voltages closer to end customer (unlocking further energy savings). Although these technologies have shown to effectively control voltages in LV networks, their potential for CVR has not been assessed before. Additionally, most CVR studies were performed in a context where distributed generation (DG) was not common. However, this has changed in many countries, with residential photovoltaic (PV) systems becoming popular. As this is likely to continue, the interactions of residential PV and CVR need to be studied. This thesis contributes to address the aforementioned literature gaps by: (i) proposing a simulation framework to characterise the time-varying voltage-demand correlation of individual end customers; (ii) developing a process to model real distribution networks (MV and LV) from DNO data; (iii) adopting a Monte Carlo-based quantification process to cater for the uncertainties related to individual customer demand; (iv) assessing the CVR benefits that can be unlocked with new LV infrastructure and different PV conditions. To accomplish (iv), first, a simple yet effective rule-based scheme is proposed to actively control voltages in OLTC-enabled LV networks without PV and using limited monitoring. It is demonstrated that by controlling voltages closer to customers, annual energy savings can increase significantly, compared to primary substation voltage reductions. Also, to understand the effect of PV on CVR, a centralized, three-phase AC OPF-based CVR scheme is proposed. This control, using monitoring, OLTCs and capacitors across MV and LV networks, actively manages voltages to minimize energy consumption in high PV penetration scenarios whilst considering MV-LV constraints. Results demonstrate that without CVR, PV systems lead to higher energy imports for customers without PV, due to higher voltages. Conversely, the OPF-based CVR scheme can effectively manage voltages throughout the day, minimising energy imports for all customers. Moreover, if OLTCs at secondary substations are available (and managed in coordination with the primary substation OLTC), these tend to regulate customer voltages close to the minimum statutory limit (lower tap positions), while the primary OLTC delivers higher voltages to the MV network to also reduce MV energy losses.
17
Dkhili, Nouha. "A model-based predictive control strategy for low-voltage power distribution grids with prolific distributed generation in Occitania." Thesis, Perpignan, 2020. https://theses-public.univ-perp.fr/2020PERP0037.pdf.
Full textAbstract:
Le terme « réseau électrique intelligent » fait référence à un réseau électrique en présence d’une abondante production décentralisée et redirigeant les flux de puissance afin que soit maintenu l’équilibre entre production et consommation électrique en temps réel. Son fonctionnement est conditionné par le respect de contraintes de stabilité, sécurité et qualité de service. Il tire profit d'une observabilité améliorée, utilise les outils de contrôle/commande avancé et offre la possibilité d’une gestion avancée de la demande.Dans le contexte du projet Smart Occitania, dont l'objectif est d’évaluer la faisabilité du concept de réseau électrique intelligent en zones rurales et péri-urbaines, ces travaux de thèse proposent une stratégie fondée sur la théorie de la commande prédictive et la gestion de charges pilotables (ici, un méthaniseur et un château d'eau) afin de maintenir l'équilibre entre production et consommation électrique dans le réseau, tout en respectant des contraintes en tension prédéfinies. La stratégie de contrôle inclue des prévisions infra-journalières de plusieurs grandeurs stochastiques qui interviennent dans le système, obtenues par le biais d’une régression non paramétrique par processus Gaussien.La contribution principale de cette thèse est double : la formulation d’un problème d'optimisation pour gérer la commande tout ou rien du château d'eau sans avoir recours à la programmation non linéaire mixte en nombres entiers ou à une relaxation et l'utilisation d'intervalles de confiance fournis par le module de prévision pour réduire les dépassements de tension dus aux erreurs de prévision.Les résultats obtenus témoignent du potentiel de la commande prédictive pour la gestion de charges pilotables dans une optique de réduction de l'écart entre production et consommation, tout en respectant des contraintes en tensionThe term ''smart grid'' refers to a modern power grid that successfully integrates prolific distributed generation with end loads and efficiently reroutes power flows to balance supply and demand in real time with respect to stability, quality, and safety constraints. It relies on improved observability and advanced control techniques, and offers the possibility of advanced demand side management.In the context of the Smart Occitania project, which aims to study the feasibility of the smart grid concept for rural and suburban power distribution grids, this work proposes a model-based predictive control strategy based on flexible asset management (herein a biogas plant and a water tower) that aims to balance power supply and demand within the power grid while maintaining voltage levels within prescribed margins. The control scheme incorporates intraday forecasts of various stochastic quantities that impact the system, procured through Gaussian process regression.The main contribution of this thesis is twofold: the predictive controller's optimisation problem is formulated in such a way that the ON/OFF of the water tower is handled without recourse to mixed-integer nonlinear programming or relaxation, and the confidence intervals provided by the forecast module are utilised to minimize voltage overshooting due to forecasting errors.The results illustrate the promise of a predictive controller relying on renewable-energy-based flexible assets to reduce the gap between power supply and demand, while upholding the power grid's voltage constraints
18
Tinarwo, David. "Design of village power and micro-grids for rural areas of Zimbabwe with specific attention to voltage regulation on low voltage meshed distribution grids." Kassel Kassel Univ. Press, 2008. http://d-nb.info/992891205/04.
Full text
19
Vai, Vannak. "Planning of low voltage distribution system with integration of PV sources and storage means : case of power system of Cambodia." Thesis, Université Grenoble Alpes (ComUE), 2017. http://www.theses.fr/2017GREAT044/document.
Full textAbstract:
La consommation d'énergie augmente d'année en année en raison de la croissance de la population et des conditions économiques. Afin de répondre aux besoins de la population et de la société d'utiliser l'électricité, le Gouvernement Cambodgien a mis en place la politique de promotion et d'encouragement du développement de l’électrification ; tous les villages auront de l'électricité d'ici 2020 et au moins 70% des domiciles auront accès à la bonne qualité du réseau électrique d'ici 2030. Pour réussir ces objectifs, l'étude et le développement de la méthodologie du réseau de distribution basse tension (BT) sont étudiés. Cette thèse étudie la planification du réseau de distribution BT avec intégration de Photovoltaïque (PV) et de stockage d’énergie de batterie (BES). La première partie est développée la méthode de planification à long terme pour tacler le défi de l'incertitude sur la charge en zone urbaine ;le nouvel algorithme a été développé pour rechercher l'architecture optimale de minimisation du coût d’investissement (CAPEX) et d’exploitation (OPEX) qui respecte l'ensemble de contraintes topologies et électriques (courant et tension) grâce à la programmation linéaire mixte en nombres entiers à contraintes quadratiques (PLMNECQ), le plus court chemin , first-fit bin-packing, et la méthode de Monte-Carlo. La deuxième partie est traité de l'extension de la zone de couverture de l'électricité avec deux solutions possibles, sont le renforcement du réseau et l'intégration de PV-BES pour le village rural ; l'algorithme génétique (GA) et la technique itérative ont été codés pour rechercher l’emplacement et la capacité. La dernière partie du travail est concentrée sur la planification du réseau de distribution résidentielle BT pour les zones non électrifiées aux rural et urbain grâce à l'architecture optimale et l'intégration de PV-BES sur l'horizon de planificationThe energy consumption is increasing year by year due to the growth of population and the economic conditions. In order to meet the need of population and society to use electricity, the Cambodian government has established the policy to promote and encourage the development of electrification; all the villages will have electricity by the year 2020, and at least 70% of households will have access to grid quality by the year 2030. To achieve these goals, the study and development of methodology on the Low-Voltage (LV) distribution system are investigated. This thesis studies the planning of LV distribution system with integration of Photovoltaic (PV) and Battery Energy Storage (BES). The first part is developed the long-term planning method to tackle the challenge of load demand uncertainty in urban area; the novel algorithm was developed to search for the optimal architecture of minimizing the capital expenditure (CAPEX) and the operation expenditure (OPEX) which respects to the set of topology and electrical (current and voltage) thank to mixed integer quadratically constrained programming (MIQCP), shortest-path, first-fit bin-packing, and Monte-Carlo method. The second part is dealt with the extension of electricity coverage area with two possible solutions which are grid reinforcement and integration of PV-BES for rural village; the Genetic algorithm (GA) and iterative technique were coded to search for location and sizing. The last part is concentrated on the planning of residential low-voltage distribution system in both rural and urban for non-electrified area thanks to the optimal architecture and PV-BES integration over the planning horizon
20
Tinarwo, David [Verfasser]. "Design of village power and micro-grids for rural areas of Zimbabwe with specific attention to voltage regulation on low voltage meshed distribution grids / David Tinarwo." Kassel : Kassel University Press, 2009. http://d-nb.info/1006972293/34.
Full text
21
Squaiella, Davi José Ferreira. "Planejamento agregado em redes de distribuição secundária - modelo alternativo para empresas com cadastro de redes reduzido." Universidade de São Paulo, 2004. http://www.teses.usp.br/teses/disponiveis/3/3143/tde-09082005-074944/.
Full textAbstract:
As redes secundárias de distribuição são item de extrema importância no processo de levar a energia produzida de uma fonte até o consumidor final. Dentro de uma Empresa Concessionária de Distribuição de Energia Elétrica o setor de planejamento, juntamente com o grupo técnico, deve realizar o planejamento dos investimentos necessários nos níveis de alta, média e baixa tensão, sendo que para a baixa tensão (redes secundárias de distribuição), normalmente utilizam-se os dados históricos e a média de investimentos dos últimos anos (de três a cinco últimos anos). Em geral não são encontrados nestas Empresas os cadastramentos das redes secundárias de distribuição ou então, quando estes existem, muitas vezes não são confiáveis. Neste ponto, esta dissertação de mestrado apresentará, aplicará e discutirá os resultados de uma metodologia de geração de redes secundárias de distribuição a partir dos dados das redes primárias de distribuição (média tensão) e dos ativos da Empresa, tendo como foco os investimentos necessários para estas dentro do planejamento agregado de investimentos. O trabalho proposto visa criar condições para que as Empresas enquadradas na situação anterior possam realizar o seu planejamento de baixa tensão valendo-se da aplicação de uma metodologia capaz de gerar tais redes. Uma vez criadas, tais redes serão inseridas dentro de um software de planejamento agregado de investimentos que fornecerá o valor total das aplicações necessárias para os próximos dez anos (planejamento decenal longo prazo). Ao final do processo, poderá ser observado que os resultados obtidos são muito próximos dos valores esperados para as redes secundárias reais e, com isto, a dissertação discutirá como a metodologia foi implementada, os detalhes da aplicação e, até mesmo, todo o processo de planejamento para três Empresas Concessionárias de Distribuição de Energia Elétrica. Já de posse dos resultados, poderá afirmar-se que o processo produziu valores de muito boa aderência e, assim, os investimentos obtidos para as redes secundárias poderão ser aceitos pelo grupo de planejamento da Empresa. Como conseqüência dos valores de investimentos obtidos para os dez anos, poderão ser observados ainda, guardadas algumas considerações especiais, os valores dos custos marginais de baixa tensão, item de grande importância no planejamento de redes de distribuição.The low voltage distribution networks are an item of extreme importance in the process of delivering the produced energy from a plant (supply) to the final consumer. In an Electric Power Distribution Company the planning group (sector), together with the technical group, must accomplish the planning of the necessary investments in the high voltage, medium voltage and low voltage levels, and for low voltage distribution networks, usually the historical data and the average of investments of the last years are used (from three to last five years). In general the databases of low voltage networks are not found in these Companies or then, when these exist, a lot of times they are not reliable. For this, this article will show, apply and discuss the results of a methodology for generating low voltage distribution networks starting from the database of the medium voltage distribution networks and of the assets of the Company, having as focus the necessary investments for these networks in planning of investments. The proposed work wishes to create conditions so that the Companies that are in the previous situation can accomplish their planning on low voltage distribution networks using a methodology capable to generate such nets. Once created, such nets will be inserted in a software of planning of investments that will supply the total amount of investments for them for the next ten years (long period planning). In the end of the process, it will be observed that the obtained results are very close to the expected values for the real low voltage distribution networks and, with this, the article will discuss how the methodology was implemented, the details of the application and, even, the whole planning process for three Electric Power Distribution Companies. With the results, it will be affirmed that the process produces values of very good adherence and, for this, the investments obtained for low voltage distribution networks can be accepted by the planning group in the Company. As a consequence of the investments values obtained for the ten years, it will be able to be observed, kept some special considerations, the values of the marginal costs of low voltage, item of great importance in the planning of distribution networks.
22
López, Claudio David. "Shortening time-series power flow simulations for cost-benefit analysis of LV network operation with PV feed-in." Thesis, Uppsala universitet, Elektricitetslära, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-242099.
Full textAbstract:
Time-series power flow simulations are consecutive power flow calculations on each time step of a set of load and generation profiles that represent the time horizon under which a network needs to be analyzed. These simulations are one of the fundamental tools to carry out cost-benefit analyses of grid planing and operation strategies in the presence of distributed energy resources, unfortunately, their execution time is quite substantial. In the specific case of cost-benefit analyses the execution time of time-series power flow simulations can easily become excessive, as typical time horizons are in the order of a year and different scenarios need to be compared, which results in time-series simulations that require a rather large number of individual power flow calculations. It is often the case that only a set of aggregated simulation outputs is required for assessing grid operation costs, examples of which are total network losses, power exchange through MV/LV substation transformers, and total power provision from PV generators. Exploring alternatives to running time-series power flow simulations with complete input data that can produce approximations of the required results with a level of accuracy that is suitable for cost-benefit analyses but that require less time to compute can thus be beneficial. This thesis explores and compares different methods for shortening time-series power flow simulations based on reducing the amount of input data and thus the required number of individual power flow calculations, and focuses its attention on two of them: one consists in reducing the time resolution of the input profiles through downsampling while the other consists in finding similar time steps in the input profiles through vector quantization and simulating them only once. The results show that considerable execution time reductions and sufficiently accurate results can be obtained with both methods, but vector quantization requires much less data to produce the same level of accuracy as downsampling. Vector quantization delivers a far superior trade-off between data reduction, time savings, and accuracy when the simulations consider voltage control or when more than one simulation with the same input data is required, as in such cases the data reduction process can be carried out only once. One disadvantage of this method is that it does not reproduce peak values in the result profiles with accuracy, which is due to the way downsampling disregards certain time steps in the input profiles and to the averaging effect vector quantization has on the them. This disadvantage makes the simulations shortened through these methods less precise, for example, for detecting voltage violations.
23
Bassi, Welson. "Estudo de surtos em redes secundárias de distribuição devido a descargas atmosféricas diretas na rede primária." Universidade de São Paulo, 1999. http://www.teses.usp.br/teses/disponiveis/3/3143/tde-10102017-100131/.
Full textAbstract:
Este trabalho apresenta uma análise dos surtos em redes aéreas secundárias de distribuição causados por descargas atmosféricas diretas no circuito primário. Alguns trabalhos publicados sobre o fenômeno são comentados, sendo também analisados vários outros estudos relativos à modelagem de componentes. No trabalho, os principais componentes da rede foram modelados e incluídos na representação de uma topologia típica (com as linhas primária e secundária). Assim, foram considerados: transformador de distribuição, isoladores, pára-raios, cargas (consumidores) e resistências de aterramento. Os modelos foram validados, quando possível, através de ensaios em laboratório. Algumas alternativas de proteção da rede secundária foram consideradas. Foi verificada a influência de alguns parâmetros relevantes tais como amplitude e tempo de frente da corrente da descarga, resistências de aterramento, modelos de cargas e posição da descarga. Os resultados foram obtidos por simulações computacionais realizadas através do programa ATP (Alternative Transients Program). São apresentadas formas de onda de sobretensões nos consumidores. Também são apresentados e discutidos valores de corrente e energia nos dispositivos de proteção, fornecendo informações sobre as alternativas de proteção.This work presents an evaluation of surges in low-voltage overhead distribution lines caused by direct lightning strikes in medium voltage lines. Some publications concerning the phenomenon are commented and several other studies used during the process of modeling of the components are also analysed. The main components of the distribution system were modeled and included. So, a typical distribution network topology (with the primary and secondary lines) was represented including its components: distribution transformer, insulators, surge arresters, loads and ground resistances. The performance of the developed models, whenever possible, was verified by laboratory tests. Some possibilities of the secondary protection were included. Parameters having major effect on the results, such as the lightning current amplitude and front time, the values of grounding resistances, the models of the loads and the lightning strike position were taken into consideration in the study. The results were obtained by simulations performed using the ATP (Alternative Transients Program). Waveforms are presented in order to provide information on the characteristics of the overvoltages in the consumers along the line. Currents, as well as energy absorbed by the low-voltage surge arresters are aldo presented and discussed, providing useful information about the performance of some protection alternatives.
24
Bassi, Welson. "Caracterização de equipamentos e instalações residenciais de baixa tensão aplicada ao estudo de transitórios de origem atmosférica." Universidade de São Paulo, 2005. http://www.teses.usp.br/teses/disponiveis/3/3143/tde-10102017-111817/.
Full textAbstract:
Este trabalho apresenta um estudo de caracterização das impedâncias de entrada, em função da frequência, de instalações residenciais de baixa tensão e diversos equipamentos eletro-eletrônicos comumente encontrados. As respostas em frequência medidas são ajustadas e modeladas por redes RLC simples, mas efetivas, que podem ser utilizadas em qualquer programa computacional para simulações de transitórios. A faixa de frequências, até 5 MHz, permite o uso desses modelos em estudos associados a transitórios atmosféricos ou causados por chaveamentos. É importante ressaltar a existência de muito poucos trabalhos nesse assunto, pois, usualmente, as instalações de baixa tensão, ou os equipamentos conectados, são representadas por simples elementos concentrados, resistores, indutores ou capacitores. Por outro lado, sabe-se que os níveis de sobretensões em um sistema, ou instalação, são fortemente dependentes das cargas conectadas e, quanto mais precisos os modelos, melhores e mais confiáveis simulações são obtidas. Este trabalho inclui simulações com o programa computacional ATP utilizando os modelos desenvolvidos para avaliação de surtos em uma rede de distribuição típica submetida a descargas atmosféricas diretas no circuito primário. Além disso, utilizando o programa Pspice, são realizadas simulações da resposta interna de uma instalação residencial, com diversos equipamentos conectados, e submetida a surtos atmosféricos em sua entrada. O trabalho concentra informações práticas e úteis sobre estudos de surtos em sistemas e instalações de baixa tensãoThis work presents a study of impedance characteristics, over a wide range of frequencies, of residential low-voltage installations and electric-electronic appliances, commonly found in residential installations. The measured frequency responses are fitted and modeled by simple, but effective, RLC networks, that can be used in any software for transient simulations. The range of frequencies, up to 5 MHz, allows the use of these models considering lightning or switching studies. It is of importance to point the lack of publications focusing this topic, because usually the low-voltage installations, or connected equipment, are represented by simple lumped components inductances, resistances or capacitances. Otherwise, it is well known that the overvoltage level of a system, or installation, is strongly dependent on the connected loads and for more precise models, better and more reliable simulation results are obtained. This work includes ATP software simulations using the developed models for evaluation of surges in a typical distribution network subjected to direct lightning strikes at the primary circuit. Furthermore, simulations of internal response of a low-voltage installation with connected equipment and subjected to lightning surges in its entrance is performed using the Pspice software. The work summarizes practical and useful information about the low-voltage surge studies on low-voltage systems.
25
Foltýn, Petr. "Řešení elektrizace nové lokality elektrickou energií." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2011. http://www.nusl.cz/ntk/nusl-219030.
Full textAbstract:
This master’s thesis is concerned with the proposal of new locality electrification. There are 59 detached houses. The thesis is divided into theoretical part and computational part. In the theoretical part, there are all documents necessary for the successful proposal of the electrification. In the computational part is drafted distribution substation, high voltage power cable, proposal of low voltage power cables and protection. Each part is made for two versions (for the degree of electrification A and for the degree of electrification C) and recorded in cadastral maps. The proposal of distribution substation and high voltage power cable is made by traditional method - all calculations are processed by the designer. Low-voltage power cables and protection are implemented in a computer program Sichr (version 11.01) OEZ company.
26
Jestřáb, Tomáš. "Vliv akumulace na provoz distribuční sítě." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2017. http://www.nusl.cz/ntk/nusl-317079.
Full textAbstract:
This diploma thesis introduces the reader to the possible types of electric energy storage technologies, their comparisons and utilization. After its introduction, it follows the description of individual technologies and principles that are currently meaningful and useful in practice. The thesis continues with the part characterizing the ways of using the accumulation in the grid. However, the main points of this thesis include the analysis of the influence of the photovoltaic installation on the specified distribution grid operation at the low voltage level and the analysis of the influence on the grid with connected accumulation. Another important objective was the model for the calculation of steady-state, which was programmed on the basis of the theory supported by the principles of production from intermittent sources and the principle of accumulation function. The outputs of the model in the form of the calculated voltage ratios at the individual supply points and current flows at the distribution transformer point were used to evaluate the analyzes mentioned above. The courses of the calculated parameters are broken down by different scenarios (according to the period, the degree of integration of production and the accumulation or the power output of the production), graphically processed and compared from the point of view of voltage fluctuations and changes in the power (or current) balance of the supply transformer.
27
Pedral, Jacques, and Josef Abriren. "Analys av lågspänningsfördelning till signalanläggningar." Thesis, KTH, Data- och elektroteknik, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-192837.
Full textAbstract:
I denna rapport utreds hur systemdesignen av lågspänningsfördelningen för järnvägen kan kostnadseffektiviseras. I dagsläget har det utarbetats en norm kring systemdesignen som tenderar att efterbildas från år till år vilket har medfört brist på innovation inom området. Syftet med arbetet var att designa två typstationer med signalställverken M11 respektive M95, där placering samt nominell storlek av UPS:er skulle fastställas för att tillhandahålla en kostnadseffektiv lösning. Dessutom skulle kablage dimensioneras för typstationerna samt se över möjligheten att ersätta UPS:er med likriktarsystem. Stationerna baserades på två redan existerande driftplatser, Fagersta C (M11) och Skänninge (M95). Slutligen skulle olika energilagringsalternativ för UPS-system jämföras för att tillhandahålla det lämpligaste alternativet. Genom simuleringar och beräkningar i bland annat datorprogrammet El-Vis har lågspänningsfördelningen dimensionerats för typstationerna. Arbetet visar på att ett distribuerat UPS-system är att föredra ur ett ekonomiskt perspektiv gentemot ett centraliserat UPS-system. Vidare har det konstaterats att likriktarsystemet Rectiverter kan ersätta UPS:er samt att ackumulatorer är det mest passande energilagringsalternativet.This report identifies how the system design of low voltage power distribution of the railway can be more cost effective. In the current situation there is a norm on the system design that tends to be replicated each year. This has brought a lack of innovation in the field. The purpose of the thesis was to come up with two model stations with the interlocking system M11 respectively M95, where the positioning and nominal size of the UPS:s would be determined to provide a cost effective solution. Furthermore, the cable dimensioning of the model stations was computed as well as the possibility of replacing UPS-systems with rectifier-systems. The model stations were based on two already existing operating sites, Fagersta C (M11) and Skänninge (M95). Lastly, different energy storage alternatives for UPS-systems were compared to acquire the most appropriate choice. Through simulations and calculations in, inter alia, the computer program El-Vis, the low voltage power distribution was dimensioned for the model stations. The thesis shows that a distributed UPS-system is preferred in an economical point of view compared to a centralized UPS-system. Furthermore, the thesis establishes that the rectifier system Rectiverter can replace UPS:s. It also states that accumulators are the most suitable alternative for energy storage.
28
Saint-Laurent, Martin. "Modeling and Analysis of High-Frequency Microprocessor Clocking Networks." Diss., Georgia Institute of Technology, 2005. http://hdl.handle.net/1853/7271.
Full textAbstract:
Integrated systems with billions of transistors on a single chip are a now reality. These systems include multi-core microprocessors and are built today using deca-nanometer devices organized into synchronous digital circuits. The movement of data within such systems is regulated by a set of predictable timing signals, called clocks, which must be distributed to a large number of sequential elements. Collectively, these clocks have a significant impact on the frequency of operation and, consequently, on the performance of the systems. The clocks are also responsible for a large fraction of the power consumed by these systems.
The objective of this dissertation is to better understand clock distribution in order to identify opportunities and strategies for improvement by analyzing the conditions under which the optimal tradeoff between power and performance can be achieved, by modeling the constraints associated with local and global clocking, by evaluating the impact of noise, and by investigating promising new design strategies for future integrated systems.
29
Račuch, Marek. "Analýza a návrh náhrady konkrétního venkovního vedení distribuční sítě." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2017. http://www.nusl.cz/ntk/nusl-319302.
Full textAbstract:
The diploma thesis deals with the issue of the reconstruction of outdoor cables of low voltage distribution network in exchange for the cable line. It analyzes the important factors which are necessary for the preparation of the project documentation for the issue of the territorial consent. The thesis is divided into 4 main chapters. After the first chapter there is introduced chapter 2, which shows the differences between cable and outdoor cables with their advantages and disadvantages. Chapter 3 deals with the guiding principles for low-voltage cable design and the types of equipment needed for the proper operation of a particular distribution network while respecting the requirements of valid PNEs and ČSNs. Chapter 4 explains the chronology of the process leading to the formulation of a basic technical proposal, which is further addressed in Chapter 5, which deals with the complete formulation of the project documentation for the issue of territorial consent.
30
Thomas, Lee James. "Connection imbalance in low voltage distribution networks." Thesis, Cardiff University, 2015. http://orca.cf.ac.uk/84259/.
Full textAbstract:
On British electricity distribution networks, the phase to which single phase loads and generators are connected is, in most cases, unknown. There is concern that large imbalances in connection will limit the capacity of the network to support distributed generation as well as the electrification of heating and transport. The roll-out of Smart Metering in Britain, expected to be completed by the end of 2020, provides Distribution Network Operators with a means to predict the phase of single phase connections and more accurately assess the impact of increased distributed generation. This thesis examines these possibilities. There are three main sections: 1. Development of a steady state LV feeder modelling program allowing for flexible definition of connection imbalance and suitable for use with a supercomputer. 2. Development of a stochastic method to assess the combined influence (on voltages, currents and losses) of connection imbalance and photovoltaic generation. 3. Creation of an algorithm for the prediction of phase connections using Smart Meter Data, based on the GB smart metering proposals. The LV feeder model uses an unbalanced load flow based on network reduction and re-expansion with nodal analysis. It was validated using PSCAD. The feeder model uses a TNS earthing arrangement; this was shown to be equivalent to TN-C-S in normal operation, allowing for simpler modelling. A metric for connection imbalance was introduced – the highest proportion of houses connected to any phase. The model is capable of varying connection imbalance by changing the phase to which each house is connected. The connection imbalance was varied by randomly allocating houses to different phases. Demand profiles were created stochastically and PV generation was added to a varied proportion of houses (0 to 100% in 10% steps). More than 19 million unbalanced load flow calculations were performed using a supercomputer. It was found that, for a typical urban feeder serving residential properties, connection imbalance is not a significant problem for DNOs until it becomes severe (>60% of houses on one phase). The phase identification algorithm combines two methods found in the literature; voltage measurement clustering and solution of the subset sum problem. It uses vii smart meter voltage profiles and active power profiles with current measured at the supply substation. It correctly predicted the phase connection for 97% of smart meters, using simulated data representing a set 100 different connection configurations, across 6 different days (different sets of demand profiles) with a measurement averaging timeframe of 30 minutes.
31
Park, Byeong-Ha. "A low-voltage, low-power, CMOS 900MHZ frequency synthesizer." Diss., Georgia Institute of Technology, 1997. http://hdl.handle.net/1853/16686.
Full text
32
Chen, Mingdeng. "Low-voltage, low-power circuits for data communication systems." Diss., Texas A&M University, 2003. http://hdl.handle.net/1969.1/1585.
Full textAbstract:
There are growing industrial demands for low-voltage supply and low-power consumption circuits and systems. This is especially true for very high integration level and very large scale integrated (VLSI) mixed-signal chips and system-on-a-chip. It is mainly due to the limited power dissipation within a small area and the costs related to the packaging and thermal management. In this research work, two low-voltage, low-power integrated circuits used for data communication systems are introduced. The first one is a high performance continuous-time linear phase filter with automatic frequency tuning. The filter can be used in hard disk driver systems and wired communication systems such as 1000Base-T transceivers. A pseudo-differential operational transconductance amplifier (OTA) based on transistors operating in triode region is used to achieve a large linear signal swing with low-voltage supplies. A common-mode (CM) control circuit that combines common-mode feedback (CMFB), common-mode feedforward (CMFF), and adaptive-bias has been proposed. With a 2.3V single supply, the filters total harmonic distortion is less than 44dB for a 2VPP differential input, which is due to the well controlled CM behavior. The ratio of the root mean square value of the ac signal to the power supply voltage is around 31%, which is much better than previous realizations. The second integrated circuit includes two LVDS drivers used for high-speed point-to-point links. By removing the stacked switches used in the conventional structures, both LVDS drivers can operate with ultra low-voltage supplies. Although the Double Current Sources (DCS) LVDS driver draws twice minimum static current as required by the signal swing, it is quite simple and achieves very high speed operation. The Switchable Current Sources (SCS) LVDS driver, by dynamically switching the current sources, draws minimum static current and reduces the power consumption by 60% compared to the previously reported LVDS drivers. Both LVDS drivers are compliant to the standards and operate at data rates up to gigabits-per-second.
33
Balasubramanian, Sidharth. "Low-voltage and low-power libraries for Medical SoCs." The Ohio State University, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=osu1259776639.
Full text
34
Yu, Yue. "Low-power low-phase-noise voltage-controlled oscillator design." The Ohio State University, 2006. http://rave.ohiolink.edu/etdc/view?acc_num=osu1413475974.
Full text
35
Gutnik, Vadim. "Variable supply voltage for low power DSP." Thesis, Massachusetts Institute of Technology, 1996. http://hdl.handle.net/1721.1/36088.
Full text
36
Li, Wei Ph D. Massachusetts Institute of Technology Department of Electrical Engineering and Computer Science. "Very-high-frequency low-voltage power delivery." Thesis, Massachusetts Institute of Technology, 2013. http://hdl.handle.net/1721.1/82352.
Full textAbstract:
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2013.Cataloged from PDF version of thesis.
Includes bibliographical references (p. 217-223).
Power conversion for the myriad low-voltage electronic circuits in use today, including portable electronic devices, digital electronics, sensors and communication circuits, is becoming increasingly challenging due to the desire for lower voltages, higher conversion ratios and higher bandwidth. Future computation systems also pose a major challenge in energy delivery that is difficult to meet with existing devices and design strategies. To reduce interconnect bottlenecks and enable more flexible energy utilization, it is desired to deliver power across interconnects at high voltage and low current with on- or over-die transformation to low voltage and high current, while providing localized voltage regulation in numerous zones. This thesis introduces elements for hybrid GaN-Si dc-de power converters operating at very high frequencies (VHF, 30-300 MHz) for low-voltage applications. Contributions include development of a new VHF frequency multiplier inverter suitable for step-down power conversion, and a Si CMOS switched-capacitor step-down rectifier. These are applied to develop a prototype GaN-Si hybrid dc-dc converter operating at 50 MHz. Additionally, this thesis exploits these elements to propose an ac power delivery architecture for low-voltage electronics in which power is delivered across the interconnect to the load at VHF ac, with local on-die transformation and rectification to dc. With the proposed technologies and emerging passives, it is predicted that the ac power delivery system can achieve over 90 % efficiency with greater than 1 W/mm² power density and 5:1 voltage conversion ratio. A prototype system has been designed and fabricated using a TSMC 0.25 [mu]m CMOS process to validate the concept. It operates at 50 MHz with output power of 4 W. The prototype converter has 8:1 voltage conversion ratio with input voltage of 20 V and output voltage of 2.5 V. To the author's best knowledge, this is the first ac power delivery architecture for low-voltage electronics ever built and tested.
by Wei Li.
Ph.D.
37
Urquhart, Andrew J. "Accuracy of low voltage electricity distribution network modelling." Thesis, Loughborough University, 2016. https://dspace.lboro.ac.uk/2134/21799.
Full textAbstract:
The connection of high penetrations of new low carbon technologies such as PV and electric vehicles onto the distribution network is expected to cause power quality problems and the thermal capacity of feeder cables may be exceeded. Replacement of existing infrastructure is costly and so feeder cables are likely to be operated close to their hosting capacity. Network operators therefore require accurate simulation models so that new connection requests are not unnecessarily constrained. This work has reviewed recent studies and found a wide range of assumptions and approximations that are used in network models. A number of these have been investigated further, focussing on methods to specify the impedances of the cable, the impacts of harmonics, the time resolution used to model demand and generation, and assumptions regarding the connectivity of the neutral and ground conductors. The calculation of cable impedances is key to the accuracy of network models but only limited data is available from design standards or manufacturers. Several techniques have been compared in this work to provide guidance on the level of detail that should be included in the impedance model. Network modelling results with accurate impedances are shown to differ from those using published data. The demand data time resolution has been shown to affect estimates of copper losses in network cables. Using analytical methods and simulations, the relationship between errors in the loss estimates and the time resolution has been demonstrated and a method proposed such that the accuracy of loss estimates can be improved. For networks with grounded neutral conductors, accurate modelling requires the resistance of grounding electrodes to be taken into account. Existing methods either make approximations to the equivalent circuit or suffer from convergence problems. A new method has been proposed which resolves these difficulties and allows realistic scenarios with both grounded and ungrounded nodes to be modelled. In addition to the development of models, the voltages and currents in a section of LV feeder cable have been measured. The results provide a validation of the impedance calculations and also highlight practical difficulties associated with comparing simulation models with real measurement results.
38
Twining, Erika. "Voltage compensation in weak distribution networks using shunt connected voltage source converters." Monash University, Dept. of Electrical and Computer Systems Engineering, 2004. http://arrow.monash.edu.au/hdl/1959.1/9701.
Full text
39
Ma, Stanley Jeh-Chun. "A low-power low-voltage second-order [Sigma Delta] modulator." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape17/PQDD_0028/MQ34136.pdf.
Full text
40
Hitko, Donald A. (Donald Anthony). "A low power, low noise, 1.8 GHz voltage-controlled oscillator." Thesis, Massachusetts Institute of Technology, 1997. http://hdl.handle.net/1721.1/43316.
Full text
41
Zhang, Chenglong. "LOW-POWER LOW-VOLTAGE ANALOG CIRCUIT TECHNIQUES FOR WIRELESS SENSORS." OpenSIUC, 2014. https://opensiuc.lib.siu.edu/dissertations/982.
Full textAbstract:
This research investigates lower-power lower-voltage analog circuit techniques suitable for wireless sensor applications. Wireless sensors have been used in a wide range of applications and will become ubiquitous with the revolution of internet of things (IoT). Due to the demand of low cost, miniature desirable size and long operating cycle, passive wireless sensors which don't require battery are more preferred. Such sensors harvest energy from energy sources in the environment such as radio frequency (RF) waves, vibration, thermal sources, etc. As a result, the obtained energy is very limited. This creates strong demand for low power, lower voltage circuits. The RF and analog circuits in the wireless sensor usually consume most of the power. This motivates the research presented in the dissertation. Specially, the research focuses on the design of a low power high efficiency regulator, low power Resistance to Digital Converter (RDC), low power Successive Approximation Register (SAR) Analog to Digital Converter (ADC) with parasitic error reduction and a low power low voltage Low Dropout (LDO) regulator. This dissertation includes a low power analog circuit design for the RFID wireless sensor which consists of the energy harvest circuits (an optimized rectifier and a regulator with high current efficiency) and a sensor measurement circuit (RDC), a single end sampling SAR ADC with no error induced by the parasitic capacitance and a digital loop LDO whose line and load variation response is improved. These techniques will boost the design of the wireless sensor and they can also be used in other similar low power design.
42
Zhang, Yan. "Cost reflective network pricing for high voltage and low voltage distribution networks." Thesis, University of Bath, 2012. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.558863.
Full text
43
Mesgarzadeh, Behzad. "Low-Power Low-Jitter Clock Generation and Distribution." Doctoral thesis, Linköpings universitet, Elektroniska komponenter, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-14896.
Full textAbstract:
Today’s microprocessors with millions of transistors perform high-complexitycomputing at multi-gigahertz clock frequencies. Clock generation and clockdistribution are crucial tasks which determine the overall performance of amicroprocessor. The ever-increasing power density and speed call for newmethodologies in clocking circuitry, as the conventional techniques exhibit manydrawbacks in the advanced VLSI chips. A significant percentage of the total dynamicpower consumption in a microprocessor is dissipated in the clock distributionnetwork. Also since the chip dimensions increase, clock jitter and skew managementbecome very challenging in the framework of conventional methodologies. In such asituation, new alternative techniques to overcome these limitations are demanded. The main focus in this thesis is on new circuit techniques, which treat thedrawbacks of the conventional clocking methodologies. The presented research in thisthesis can be divided into two main parts. In the first part, challenges in design ofclock generators have been investigated. Research on oscillators as central elements inclock generation is the starting point to enter into this part. A thorough analysis andmodeling of the injection-locking phenomenon for on-chip applications show greatpotential of this phenomenon in noise reduction and jitter suppression. In thepresented analysis, phase noise of an injection-locked oscillator has been formulated.The first part also includes a discussion on DLL-based clock generators. DLLs haverecently become popular in design of clock generators due to ensured stability,superior jitter performance, multiphase clock generation capability and simple designprocedure. In the presented discussion, an open-loop DLL structure has beenproposed to overcome the limitations introduced by DLL dithering around the averagelock point. Experimental results reveals that significant jitter reduction can beachieved by eliminating the DLL dithering. Furthermore, the proposed structuredissipates less power compared to the traditional DLL-based clock generators.Measurement results on two different clock generators implemented in 90-nm CMOSshow more than 10% power savings at frequencies up to 2.5 GHz. In the second part of this thesis, resonant clock distribution networks have beendiscussed as low-power alternatives for the conventional clocking schemes. In amicroprocessor, as clock frequency increases, clock power is going to be thedominant contributor to the total power dissipation. Since the power-hungry bufferstages are the main source of the clock power dissipation in the conventional clock distribution networks, it has been shown that the bufferless solution is the mosteffective resonant clocking method. Although resonant clock distribution shows greatpotential in significant clock power savings, several challenging issues have to besolved in order to make such a clocking strategy a sufficiently feasible alternative tothe power-hungry, but well-understood, conventional clocking schemes. In this part,some of these issues such as jitter characteristics and impact of tank quality factor onoverall performance have been discussed. In addition, the effectiveness of theinjection-locking phenomenon in jitter suppression has been utilized to solve the jitterpeaking problem. The presented discussion in this part is supported by experimentalresults on a test chip implemented in 130-nm CMOS at clock frequencies up to 1.8GHz.Mikroprocessorer till dagens datorer innehåller hundratals miljoner transistorersom utför åtskilliga miljarder komplexa databeräkningar per sekund. I stort settalla operationer i dagens mikroprocessorer ordnas genom att synkronisera demmed en eller flera klocksignaler. Dessa signaler behöver ofta distribueras överhela chippet och driva alla synkroniseringskretsar med klockfrekvenser pååtskilliga miljarder svängningar per sekund. Detta utgör en stor utmaning förkretsdesigners på grund av att klocksignalerna behöver ha en extremt högtidsnoggranhet, vilket blir svårare och svårare att uppnå då chippen blir större.Idealt ska samma klocksignal nå alla synkroniseringskretsar exakt samtidigt föratt uppnå optimal prestanda, avvikelser ifrån denna ideala funktionalitet innebärlägre prestanda. Ytterliggare utmaningar inom klockning av digitala chip, är atten betydande andel av processorns totala effekt förbrukas i klockdistributionen.Därför krävs nya innovativa kretslösningar för att lösa problemen med bådeonoggrannheten och den växande effektförbrukningen i klockdistributionen. att lösa de problem som finns i dagens konventionella kretslösningar förklocksignaler på chip. I den första delen av denna avhandling presenterasforskningsresultat på oscillatorer vilka utgör mycket viktiga komponenter igeneringen av klocksignalerna på chippen. Teoretiska studier avfaslåsningsfenomen i integrerade klockoscillatorer har presenterats. Studiernahar visat att det finns stor potential för reducering av tidsonoggrannhet iklocksignalerna med hjälp av faslåsning till en annan signal. I avhandlingensförsta del presenteras även en diskussion om klockgeneratorer baserade påfördröjningslåsta element. Dessa fördröjningslåsta elementen, kända som DLLkretsar, har egenskapen att de kan fördröja en klocksignal med en bestämdfördröjning, vilket möjliggör skapandet av multipla klockfaser. En nykretsteknik har introducerats för klockgenerering av multipla klockfaser vilken reducerar effektförbrukningen och onoggranheten i DLL-baseradeklockgeneratorer. I denna teknik används en övervakningskrets vilken ser till attalla delar i klockgeneratorn utnyttjas effektivt och att oanvända kretsarinaktiveras. Baserat på experimentalla mätresultat från tillverkade testkretsar ikisel har en effektbesparing på mer än 10% uppvisats vid klockfrekvenser påupp till 2.5 GHz tillsammans med en betydande ökning av klocknoggranheten. I avhandlingens andra del diskuteras en klockdistributionsteknik som baseraspå resonans, vilken har visat sig vara ett lovande alternativ till konventionllabufferdrivna klockningstekniker när det gäller minskande effektförbrukning.Principen bakom tekniken är att återanvända den energi som utnyttjas till attladda upp klocklasten. Teoretiska resonemang har visat att storaenergibesparingar är möjliga, och praktiska mätningar på tillverkadeexperimentchip har visat att effektförbrukingen kan mer än halveras. Ettproblem med den föreslagna klockningstekniken är att data som används iberäkningarna kretsen direkt påverkar klocklasten, vilket även påverkarnoggranheten på klocksignalen. För att komma till rätta med detta problemetpresenteras en teknik, baserad på forskning inom ovan nämndafaslåsningsfenomen, som kan minska onoggrannheten på klocksignalen medöver 50%. Både effektbesparingen och förbättringen av tidsnoggranheten harverifierats med hjälp av mätningar på tillverkade chip vid frekvenser upp mot1.8 GHz.
44
Lorentz, Vincent. "Bidirectional DC voltage conversion for low power applications." Université Louis Pasteur (Strasbourg) (1971-2008), 2008. https://publication-theses.unistra.fr/public/theses_doctorat/2008/LORENTZ_Vincent_2008.pdf.
Full textAbstract:
Cette thèse se focalise sur la conversion de tension utilisée dans l’équipement mobile. Le concept présenté combine le convertisseur de tension avec l’unité de gestion de l’énergie en constituant un convertisseur de puissance intelligent (IPC) intégré dans la batterie et capable de fournir une tension régulée et ajustable, adaptable à tout équipement mobile. L’IPC doit permettre un flux d’énergie bidirectionnel car la batterie doit être rechargée. L’IPC a été conçu, simulé, tracé dans le layout et fabriqué avec une finesse de gravure de 0. 18μm dans une technologie mixed-signal CMOS de UMC. L’IPC possède une tension de fonctionnement de 1. 2V-3. 6V, un courant continu maximum de 2000mA, et une fréquence de fonctionnement de 100kHz-10MHz. Des solutions nouvelles ont été développées pour l’IPC. Premièrement, une méthode pour détecter automatiquement le chargeur de batterie a été développée. Deuxièmement, une boucle de régulation continue a été développée. Elle permet d’augmenter ou de diminuer la tension à convertir dans les deux directions et à des fréquences élevées. Troisièmement, le dimensionnement dynamique de MOSFET a été développé pour maximiser l’efficacité de conversion à faible charge. Quatrièmement, une méthode d’estimation du courant moyen à travers l’inductance a été développée pour des fréquences jusqu’à 10MHz. Cinquièmement, une interface I2C a été implémentée pour permettre la configuration de l’unité de gestion de l’énergie. Comme la batterie intelligente contient un système de management de batterie et offre une tension ajustable, elle peut être facilement remplacée. L’upgrade des batteries devient possible, et l’autonomie des équipements mobiles est allongéeThis thesis focuses on the voltage conversion used in mobile equipment. The novel concept exposed consists in combining the voltage conversion unit with the battery management unit, thus building an intelligent power converter (IPC), that is integrated into the battery and is able to provide a regulated and adjustable voltage directly to the mobile equipment, thus making it adaptable to every mobile equipment. Because the battery must also be recharged, the IPC must allow a bidirectional energy flow. The IPC has been designed, simulated, laid-out and manufactured in a 0. 18 μm mixed-signal CMOS technology from UMC. The IPC requires an operating voltage between 1. 2V-3. 6V, an average load current up to 2000mA, and an operating frequency in the range of 100kHz-10MHz. Novel solutions were developed for the IPC. First, a method was developed for detecting automatically the connection of a battery charger in parallel to the load. Second, a continuous regulation loop was developed, which enables highly efficient step-up and step-down conversion in both directions and at high switching frequencies. Third, dynamic MOSFET sizing was developed, to maximize the conver-sion efficiency at light load. Fourth, a current sensing method has been developed for estimating the average inductor current at switching frequencies up to 10MHz. Fifth, an I2C interface was imple-mented, to enable digital programming of the battery management. Since the intelligent battery contains a battery management and provides an adjustable voltage, it can be easily replaced. This enables battery upgrading, so that the operating time of the mobile equipment is extended
Batteriebetriebene Mobilgeräte sind ein wichtiger Tragpfeiler des heutigen Markts, besonders seit Mobiltelefone und Digitalkameras eingeführt wurden. Allerdings haben Mobilgeräte einen Nachteil: die Batterie verfügt über eine begrenzte Kapazität, die nur auf zwei Wege erweitert werden kann. Der erste Weg besteht in der Entwicklung von neuen Batteriechemien, um die Energiedichte zu erhöhen. Der zweite Weg besteht in einer effizienteren Nutzung dieser Energie durch ein intelligenteres Ener-giemanagement. Diese Dissertation befasst sich mit dem zweiten Ansatz, und zwar mit der Span-nungswandlung, die üblicherweise in Mobilgeräten benutzt wird. Ziel des vorgestellten Konzeptes ist es, den Spannungswandler mit dem Energiemanagement zu kombinieren, um damit einen intelligen-ten Leistungswandler (IPC) zu realisieren, der in die Batterie integriert wird. Diese intelligente Batterie liefert eine geregelte und einstellbare Spannung. Damit ist sie in jedem Mobilgerät einsetzbar. Der IPC muss einen bidirektionalen Energiefluss erlauben, um die Batterie aufladen zu können. Der IPC wurde entwickelt und simuliert. Ein Layout wurde erstellt und in einer 0. 18 μm-Mixed-signal CMOS-Technologie von UMC gefertigt. Ein auf Cadence- Software basierender Full-custom-Designfluss wurde erstellt. Zusätzlich zu den Modellen von UMC wurden Monte-Carlo-Modelle entwi-ckelt, um die Variationen des Herstellungsprozesses bei den Simulationen berücksichtigen zu können. Um Elektromigration zu verhindern, wurden Designregeln geschrieben, damit eine Stromüberlastung der Metallverbindungen im Leistungsteil vermieden wird. Die technischen Daten des IPCs sind ein Betriebsspannungsbereich von 1,2 V-3,6 V, ein konstanter Laststrom bis zu 2000mA und eine Be-triebsfrequenz im Bereich von 100 kHz bis 10 MHz. Mehrere neue Lösungen wurden für den IPC entwickelt. Erstens wurde eine Methode entwickelt, um ein Batterieladegerät zu erkennen, da die Richtung des Energieflusses durch die Anwesenheit dieses Ladegerät parallel zur Last bestimmt wird. Zweitens wurde eine kontinuierliche Regelungsschleife entwickelt, die es ermöglicht, bei hohen Frequenzen die gewandelte Spannung in beide Richtungen hoch- und herunterzusetzen. Drittens wurde eine dynamische Einstellung der Weite des MOSFETs entwickelt, um den Wirkungsgrad im Schwachlastbereich zu erhöhen. Bei Frequenzen über 1MHz wurde eine absolute Wirkungsgraderhöhung von 25% erreicht. Viertens wurde für Betriebsfrequenzen bis 10MHz eine Methode zur Abschätzung des Stromes durch die Induktivität entwickelt. Fünftens wurde eine digitale I2C-Schnittstelle implementiert, um das Konfigurieren des Energiemanagement-systems zu ermöglichen. Da die intelligente Batterie ein Batteriemanagementsystem enthält und eine einstellbare Spannung ausgibt, kann sie einfach ausgetauscht werden. Das Upgraden von Batterien wird möglich (z. B. Ande-re Chemie, höhere Energiedichte), so dass die Betriebsdauer erweitert wird. Die Integration der Elekt-ronik erlaubt es, zusätzlich Schutzfunktionen gegen Kurzschlüsse, Überladung oder Fälschungen unterzubringen
45
Chan, Tat Fu. "Low power low phase noise CMOS LC quadrature voltage-controlled oscillators /." View abstract or full-text, 2007. http://library.ust.hk/cgi/db/thesis.pl?ECED%202007%20CHANT.
Full text
46
Yehia, Ali Mustafa Doaa Mokhtar. "Deliverable Power Characteristics in Low-Voltage DC Distribution System Based on Voltage Stability." Thesis, 2011. http://hdl.handle.net/2237/16630.
Full text
47
Van, Rhyn Pierre. "Probabilistic low voltage distribution network design for aggregated light industrial loads." Thesis, 2015. http://hdl.handle.net/10210/13361.
Full textAbstract:
D.Ing.This thesis initially reviews current empirical and probabilistic electrical load models available to distribution design engineers today to calculate voltage regulation levels in low voltage residential, commercial and light industrial consumer networks. Although both empirical and probabilistic techniques have extensively been used for residential consumers in recent years, it has been concluded that commercial and light industrial consumer loads have not been a focus area of probabilistic load study for purposes of low voltage feeder design. However, traditional empirical techniques, which include adjustments for diversity to accommodate non-coincidental electrical loading conditions, have generally been found to be applied using in-house design directives with only a few international publications attempting to address the problem. This work defines the light industrial group of consumers in accordance with its international Standard Industrial Classification (SIC) and presents case studies on a small group of three different types of light industrial sub-classes, It is proposed and proved that the electrical load models can satisfactorily be described as beta-distributed load current models at the instant of group or individual maximum power demand on typical characteristic 24-hour load cycles. Characteristic mean load profiles were obtained by recording repetitive daily loading of different sub-classes, ensuring adequate sample size at all times. Probabilistic modelling of light industrial loads using beta-distributed load current at maximum demand is a new innovation in the modelling of light industrial loads. This work is further -complemented by the development of a new probabilistic summation algorithm in spreadsheet format. This algorithm adds any selected number of characteristic load current profiles, adjusted for scale, power factor, and load current imbalance, and identifies the combined instant of group or system maximum demand. This spreadsheet also calculates the characteristic beta pdf parameters per phase describing the spread and profile of the combined system loading at maximum demand. These parameters are then conveniently used as input values to existing probabilistic voltage regulation algorithms to calculate voltage regulation in single-, bi- and three-phase low voltage distribution networks.
48
Hsiao, Yu-Yi, and 蕭育宜. "Innovative Design of Smart and Safe Protection for Low Voltage Distribution Power System." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/8dmwj9.
Full textAbstract:
碩士國立臺灣科技大學
電機工程系
106
The purpose of this thesis is to study the design and planning an innovative smart and safe protection for low voltage distribution power system. Enormous and various home appliances are widely used to seek better quality of life and safer living environment during economy growth ages. However, if the overloaded existed in the distribution branches for a long time and the protective devices, such as No Fuse circuit Breaker (NFB), could not normally activated, disasters with high losses of life and property damage may occur, due to the electrical wiring malfunction. To prevent an electricity crisis, a set of safety and energy source management protection coordination mechanism has to be built into the power distribution system of the building. It can inform the uses indoor in advance. In this thesis, the load current of the socket outlet is measured by the instantaneous current measurement of the Hall effect sensor, and the signal is transmitted through the single-chip interface circuit to the internal power source distribution box by power line communication (PLC) to evaluate the overall load condition of the distribution branch, and then transmitting the safety margin message returns to the branch socket outlets, which will show the socket outlet load conditions with different color indication by LED. It is proven the protective algorithm and innovative design to inform the user not to use the overload socket outlets are helpful for achieving raising the overload protection of the branches, and reducing electric fire hazards.
49
Wu, Meng-Chun Merelda. "Investigation into the steady-state load sharing of weak sources in a low voltage three-phase islanded microgrid." Thesis, 2016. http://hdl.handle.net/10539/21052.
Full textAbstract:
A dissertation submitted to the Faculty of Engineering and the Built Environment,
University of the Witwatersrand, in ful lment of the requirements for the degree of
Master of Science in Engineering.
Johannesburg, 2016This research investigates the power sharing between distributed energy resources with voltage and frequency droop control. A case study based on voltage sources in an islanded microgrid is set up in the laboratory, referred to as: The Example Microgrid. The Example Microgrid consists of two synchronous generators, active and reactive power loads. A simulation model is constructed based on the laboratory set-up, where componentwise and system-wise testing are completed. The simulation results are validated with the experimental set-up, and it is concluded that the model accurately represents the physical system under steady-state conditions. Further simulation studies on conventional droop controllers are conducted based on the Example Microgrid model. The results indicate that the use of conventional droop control is inappropriate for small, low-voltage islanded microgrids. As a possible application of this work, three variations of adapted droop controllers are simulated and their performance evaluated. It is found that with the adapted droop controllers, the power sharing error can be minimised
M T 2016
50
Hwang, Jiing-Yi, and 黃景一. "A Case Study of Earth Leakage Currents and Ground Potential Distributions of Low Voltage Power Distribution System in The SRRC Plant." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/99kuyh.
Full textAbstract:
碩士中原大學
電機工程研究所
91
Abstract This thesis is to study a practical case of Earth Leakage Current and Ground Potential Distribution of Low Voltage Power Distribution System in The Synchrotron Radiation Research Center plant (SRRC). The distribution circuit to be studied is one of the circuits power supplying to the electron beam control system. A circuit model of the three-phase fire-wire distribution circuit is first constructed based on the “Decoupled Technique“ for the simulation. The Decoupled Technique will reduce the dimension of circuit model and increase the precision of simulation results. The simulations of earth leakage currents and potential distribution have done not only for the existent case but also for various affection parameters which include load variations, unbalance three phase loads, grounding resistances and the neutral lines and ground wires associated parameters. The simulation results have shown that the existent earth leakage current, and potentials can attain to several Ampere and over ten volt, respectively, due to the root causes of unbalance load and with multi-grounded neutral line. Higher earth leakage current can be found at the transformer neutral point. The simulation results of earth leakage current is agreement with the measurement data at some panel ground buses. This shows that the analysis results can provide valuable information of improving the performance of grounding system in SRRC.