Dissertations / Theses on the topic 'Maximum Power Point Tracking System'

An investigation into the design of a stand-alone photovoltaic water pumping system for supplying rural areas is presented. It includes a study of system components and their modelling. The PV water pumping system comprises a solar-cell-array, DC-DC buck chopper and permanent-magnet DC motor driving a centrifugal pump. The thesis focuses on increasing energy extraction by improving maximum power point tracking (MPPT). From different MPPT techniques previously proposed, the perturb and observe (P&O) technique is developed because of its ease of implementation and low implementation cost. A modified variable step-size P&O MPPT algorithm is investigated which uses fuzzy logic to automatically adjust step-size to better track maximum power point. Two other MPPT methods are investigated: a new artificial neural network (ANN) method and fuzzy logic (FL) based method. These use PV source output power and the speed of the DC pump motor as input variables. Both generate pulse width modulation (PWM) control signals to continually adjust the buck converter to maximize power from the PV array, and thus motor speed and the water discharge rate of a centrifugal pump. System elements are individually modelled in MATLAB/SIMULINK and then connected to assess performance under different PV irradiation levels. First, the MP&O MPPT technique is compared with the conventional P&O MPPT algorithm. The results show that the MP&O MPPT has faster dynamic response and eliminates oscillations around the MPP under steady-state conditions. The three proposed MPPT methods are implemented in the simulated PV water pumping system and compared. The results confirm that the new methods have improved energy extraction and dynamic tracking compared with simpler methods.

This thesis proposes a new maximum power point tracking (MPPT) method for photovoltaic (PV) systems using Kalman filter. The Perturbation & Observation (P&O) method is widely used due to its easy implementation and simplicity. The P&O usually requires a dithering scheme to reduce noise effects, but the dithering scheme slows the tracking response time. Tracking speed is the most important factor for improving efficiency under frequent environmental change. The proposed method is based on the Kalman filter. An adaptive MPPT algorithm which uses an instantaneous power slope has introduced, but process and sensor noises disturb its estimations. Thus, applying the Kalman filter to the adaptive algorithm is able to reduce tracking failures by the noises. It also keeps fast tracking performance of the adaptive algorithm, so that enables using the Kalman filter to generate more powers under rapid weather changes than using the P&O. For simulations, a PV system is introduced with a 30kW array and MPPT controller designs using the Kalman filter and P&O. Simulation results are provided the comparison of the proposed method and the P&O on transient response for sudden system restart and irradiation changes in different noise levels. The simulations are also performed using real irradiance data for two entire days, one day is smooth irradiance changes and the other day is severe irradiance changes. The proposed method has showed the better performance when the irradiance is severely fluctuating than the P&O while the two methods have showed the similar performances on the smooth irradiance changes.<br>Master of Science

La creixent demanda energètica, l’esgotament dels combustibles fòssils i l’augment de l’escalfament global a causa de l’emissió de carboni ha donat lloc a la necessitat d’un sistema energètic alternatiu, global i respectuós amb el medi ambient. L’energia solar es considera una de les formes d’energia més inesgotables d’aquest univers, però té el problema de la baixa eficiència a causa de les diferents condicions ambientals. El panell solar presenta un comportament no lineal en condicions climàtiques reals i la potència de sortida fluctua amb la variació de la irradiació solar i la temperatura. El canvi de les condicions meteorològiques i el comportament no lineal dels sistemes fotovoltaics suposen un repte en el seguiment de diferents PowerPoint màxims. Per tant, per extreure i lliurar contínuament la màxima potència possible del sistema fotovoltaic, en determinades condicions ambientals, s’ha de formular l’estratègia de control de seguiment del punt de potència màxima (MPPT) que funcioni contínuament el sistema fotovoltaic al seu MPP. Es necessita un controlador no lineal robust per garantir el MPPT mitjançant la manipulació de les línies no lineals d’un sistema i el fa robust contra les condicions ambientals canviants. El control de mode lliscant (SMC) s’utilitza àmpliament en sistemes de control no lineals i s’ha implementat en sistemes fotovoltaics (PVC) per rastrejar MPP. SMC és robust contra les pertorbacions, les incerteses del model i les variacions paramètriques. Representa fenòmens indesitjables com el xerramec, inherent al fet que provoca pèrdues d’energia i calor. En aquesta tesi, en primer lloc, es formula un controlador SMC d’ordre sencer per extreure la màxima potència d’un sistema solar fotovoltaic en condicions climàtiques variables que utilitzen l’esquema MPPT de pertorbació i observació (P \ & O) del sistema fotovoltaic autònom proposat. El sistema proposat consta de dos esquemes de bucles, a saber, el bucle de cerca i el bucle de seguiment. P&O MPPT s’utilitza al bucle de cerca per generar el senyal de referència i un controlador SMC de seguiment s’utilitza a l’altre bucle per extreure la màxima potència fotovoltaica. El sistema fotovoltaic es connecta amb la càrrega mitjançant el convertidor d’alimentació electrònic DC-DC de potència. Primer es deriva un model matemàtic del convertidor d’augment i, basat en el model derivat, es formula un SMC per controlar els impulsos de la porta del commutador del convertidor d’augment. L’estabilitat del sistema de bucle tancat es verifica mitjançant el teorema d’estabilitat de Lyapunov. L’esquema de control proposat es prova amb diferents nivells d’irradiació i els resultats de la simulació es comparen amb el controlador de derivades integrals proporcionals clàssiques (PID). El SMC clàssic representa fenòmens indesitjables com el xerramec, inherent al fet que provoca pèrdues d’energia i calor. A la següent part d’aquesta tesi, es discuteix el disseny del controlador de mode lliscant adaptatiu (ASMC) per al sistema fotovoltaic proposat. El control adoptat s’executa mitjançant un ASMC i la millora s’actualitza mitjançant un algorisme d’optimització MPPT de mètode de cerca de patrons millorats (IPSM). S’utilitza un MPPT IPSM per generar la tensió de referència per tal de comandar el controlador ASMC subjacent. S’ha dut a terme una comparació amb altres dos algoritmes d’optimització, a saber, Perturb \ & Observe (P&O) i Particle Swarm Optimization (PSO) amb IPSM per MPPT. Com a estratègia no lineal, l’estabilitat del controlador adaptatiu es garanteix mitjançant la realització d’una anàlisi de Lyapunov. El rendiment de les arquitectures de control proposades es valida comparant les propostes amb la del conegut i àmpliament utilitzat controlador PID.<br>La creciente demanda de energía, el agotamiento de los combustibles fósiles y el aumento del calentamiento global debido a la emisión de carbono han hecho surgir la necesidad de un sistema energético alternativo, de eficiencia general y respetuoso con el medio ambiente. La energía solar se considera una de las formas de energía más inagotables de este universo, pero tiene el problema de la baja eficiencia debido a las diferentes condiciones ambientales. El panel solar exhibe un comportamiento no lineal en condiciones climáticas reales y la potencia de salida fluctúa con la variación de la irradiancia solar y la temperatura. Las condiciones climáticas cambiantes y el comportamiento no lineal de los sistemas fotovoltaicos plantean un desafío en el seguimiento de la variación máxima de PowerPoint. Por lo tanto, para extraer y entregar continuamente la máxima potencia posible del sistema fotovoltaico, en determinadas condiciones ambientales, se debe formular la estrategia de control de seguimiento del punto de máxima potencia (MPPT) que opere continuamente el sistema fotovoltaico en su MPP. Se requiere un controlador no lineal robusto para asegurar MPPT manejando las no linealidades de un sistema y haciéndolo robusto frente a condiciones ambientales cambiantes. El control de modo deslizante (SMC) se usa ampliamente en sistemas de control no lineales y se ha implementado en sistemas fotovoltaicos (PVC) para rastrear MPP. SMC es robusto contra perturbaciones, incertidumbres del modelo y variaciones paramétricas. Representa fenómenos indeseables como el parloteo, inherentes a él, que provocan pérdidas de energía y calor. En esta tesis, en primer lugar, se formula un controlador SMC de orden entero para extraer la máxima potencia de un sistema fotovoltaico solar en condiciones climáticas variables empleando el esquema MPPT de perturbar y observar (P&O) para el sistema fotovoltaico autónomo propuesto. El sistema propuesto consta de dos esquemas de bucles, a saber, el bucle de búsqueda y el bucle de seguimiento. P&O MPPT se utiliza en el bucle de búsqueda para generar la señal de referencia y se utiliza un controlador SMC de seguimiento en el otro bucle para extraer la máxima potencia fotovoltaica. El sistema fotovoltaico está conectado con la carga a través del convertidor elevador DC-DC electrónico de potencia. Primero se deriva un modelo matemático del convertidor elevador y, en base al modelo derivado, se formula un SMC para controlar los pulsos de puerta del interruptor del convertidor elevador. La estabilidad del sistema de circuito cerrado se verifica mediante el teorema de estabilidad de Lyapunov. El esquema de control propuesto se prueba bajo diferentes niveles de irradiancia y los resultados de la simulación se comparan con el controlador clásico proporcional integral derivado (PID). El SMC clásico describe fenómenos indeseables como el parloteo, inherente a él, que causa pérdidas de energía y calor. En la siguiente parte de esta tesis, se analiza el diseño del controlador de modo deslizante adaptativo (ASMC) para el sistema fotovoltaico propuesto. El control adoptado se ejecuta utilizando un ASMC y la mejora se actualiza utilizando un algoritmo de optimización MPPT del Método de búsqueda de patrón mejorado (IPSM). Se utiliza un IPSM MPPT para generar el voltaje de referencia para controlar el controlador ASMC subyacente. Se ha realizado una comparación con otros dos algoritmos de optimización, a saber, Perturb \ Observe (P&O) y Particle Swarm Optimization (PSO) con IPSM para MPPT. Como estrategia no lineal, la estabilidad del controlador adaptativo está garantizada mediante la realización de un análisis de Lyapunov.<br>The increasing energy demands, depleting fossil fuels, and increasing global warming due to carbon emission has arisen the need for an alternate, overall efficiency, and environment-friendly energy system. Solar energy is considered to be one of the most inexhaustible forms of energy in this universe, but it has the problem of low efficiency due to varying environmental conditions. Solar panel exhibits nonlinear behavior under real climatic conditions and output power fluctuates with the variation in solar irradiance and temperature. Changing weather conditions and nonlinear behavior of PV systems pose a challenge in the tracking of varying maximum PowerPoint. Hence, to continuously extract and deliver the maximum possible power from the PV system, under given environmental conditions, the maximum power point tracking (MPPT) control strategy needs to be formulated that continuously operates the PV system at its MPP. A robust nonlinear controller is required to ensure MPPT by handling nonlinearities of a system and making it robust against changing environmental conditions. Sliding mode control (SMC) is extensively used in non-linear control systems and has been implemented in photovoltaic systems (PV) to track MPP. SMC is robust against disturbances, model uncertainties, and parametric variations. It depicts undesirable phenomena like chattering, inherent in it causing power and heat losses. In this thesis, first, an integer order SMC controller is formulated for extracting maximum power from a solar PV system under variable climatic conditions employing the perturb and observe (P&O) MPPT scheme for the proposed stand-alone PV system. The proposed system consists of two loops schemes, namely the searching loop and the tracking loop. P&O MPPT is utilized in the searching loop to generate the reference signal and a tracking SMC controller is utilized in the other loop to extract the maximum PV power. PV system is connected with load through the power electronic DC-DC boost converter. A mathematical model of the boost converter is derived first, and based on the derived model, an SMC is formulated to control the gate pulses of the boost converter switch. The closed-loop system stability is verified through the Lyapunov stability theorem. The proposed control scheme is tested under varying irradiance levels and the simulation results are compared with the classical proportional integral derivative (PID) controller. Classical SMC depicts undesirable phenomena like chattering, inherent in it causing power and heat losses. In the next part of this thesis, the design of the adaptive sliding mode controller (ASMC) is discussed for the proposed PV system. The adopted control is executed utilizing an ASMC and the enhancement is actualized utilizing an Improved Pattern Search Method (IPSM) MPPT optimization algorithm. An IPSM MPPT is used to generate the reference voltage in order to command the underlying ASMC controller. Comparison with two other optimization algorithms, namely, a Perturb & Observe (P&O) and Particle Swarm Optimization (PSO) with IPSM for MPPT has been conducted. As a non-linear strategy, the stability of the adaptive controller is guaranteed by conducting a Lyapunov analysis. The performance of the proposed control architectures is validated by comparing the proposals with that of the well-known and widely used PID controller. The simulation results validate that the proposed controller effectively improves the voltage tracking, system power with reduced chattering effect, and steady-state error. A tabular comparison is provided at the end of each optimization algorithm category as a resume quantitative comparison. It is anticipated that this work will serve as a reference and provides important insight into MPPT control of the PV systems.

Av den frigjorda energin för en lastbils bränsle är omkring 30% i form avspillvärme i avgassystemet. Med implementation av ett spillvärmeåtervinningsystem går det att återvinna en del av den frigjorda energin i form av elektricitet till lastbilens elsystem. Två termoelektriska generatorer använder avgaserna som värmekälla och ett kylmedel som kall källa för att åstakomma en temperaturdifferans i generatorerna. Med hjälp av Seebeck-effekten går det att omvandla temperaturdifferansen till elektricitet och på så sätt avlastas motorns generator vilket medför en lägre bränsleförbrukning. Detta examensarbete innefattar utvecklandet av en funktion som maximerar nettoeffekten utvunnen från systemet. Funktionen som utvecklats är döpt till Maximum Net-power Point Tracking (MNPT) och har som uppgift att beräkna referensvärden som styrningen av systemet skall uppnå för att få ut maximal nettoeffekt. En simuleringmiljö i Matlab/Simulink är uppbyggd för att kunna implementera en kontrollstrategi för styrningen av kylmedlet samt avgasledning via bypass-ventiler. Systemet har blivit implementerat i en motorstyrenhet på en testrack somkommunicerar via CAN där givare så som temperatur och tryck avläses. Systemet har ej blivit implementerat på lastbilen då samtliga fysiska komponenter ej blev färdigställda under examensarbetets gång. En fallstudie genomfördes i simuleringsmiljön och resultaten visade att användningen av en MNPT-funktion tillät upp till 300% ökning av den återinförda nettoeffekten till lastbilens elsystem jämfört med utan användning av kontrollalgoritmer, och upp till 50% ökning jämfört med statiska referensvärden.<br>About 30% of the released energy of a truck’s fuel is waste heat in the exhaustsystem. It is possible to recover some of the energy with a waste heat recovery system that generates electricity from a temperature difference by utilising the Seebeck-effect. Two thermoelectric generators are implemented on a truck and utilises the exhaust gas as a heat source and the coolant fluid as a cold source to accomplish a temperature difference in the generators. The electricity is reintroduced to the truck’s electrical system and thus reducing the load on the electrical generator in the engine which results in lower fuel consumption. This thesis includes the construction of a function that maximises the netpowerderived from the system. The function developed is named Maximum Net Power Point Tracking (MNPT) and has the task of calculating reference values that the controllers of the system must achieve in order to obtain maximumnet-power. A simulation environment has been developed in Matlab/Simulink in order to design a control strategy to three valves and one pump. The system has been implemented on a engine control unit that has been mounted on a test rack. The engine control unit communicates through CAN to connected devices. The system has not been implemented on the truck due that all the physical components were not completed during the time of the thesis. A case study has been conducted and the results proves that the use of an MNPT-function allows up to 300% increase in regenerated net power into the trucks electrical system compared with no control algorithms, and up to 50% compared with static reference values.

Operating faraway from maximum power point decreases the generated power from photovoltaic (PV) system. For optimum operation, it is necessary to continually track the maximum power point of the PV solar array. However with huge changes in external influences and the nonlinear relationship of electrical characteristics of PV panels it is a difficult problem to identify the maximum power point as a function of these influences. Many tracking control strategies have been proposed to track maximum power point such as perturb and observe, incremental conductance, parasitic capacitance, and neural networks. These proposed methods have some disadvantages such as high cost, difficulty, complexity and nonstability. This thesis presents a novel approach based on Adaptive NeuroFuzzy Inference System (ANFIS) to predict the maximum power point utilising the actual field data, which is performed in different environmental conditions. The short circuit current and open circuit voltage are used as inputs to PV panels instead of solar irradiation and cell junction temperature. The predicted $V_{max}$from ANFIS model is used as a reference voltage for fuzzy logic controller (FLC). The FLC is used to adjust the duty cycle of the electronic switch of two types of DC-DC converter. These DC-DC converters are used to interface between the load voltage and PV panels. The duty cycle of the electronic switch of the DC-DC converter is adjusted until the input voltage of the converter tracks the predicted $V_{max}$of the PV system. FLC rules and membership functions are designed to achieve the most promising performance at different environmental conditions, different load types and different rate of changes in the duty cycle of Buck-Boost and Buck converters. The membership functions and fuzzy rules of FLC are designed to balance between different required features such as quick tracking under different environmental conditions, high accuracy, stability and high efficiency.

The increase in demand for renewable energy sources has been exponential in recent years and is mainly driven by factors that include the growth of greenhouse emissions and the decline in fossil fuel reservoirs. Photovoltaic (PV) energy, one of the more prominent renewable energy sources, produces electricity directly from sunlight, noiselessly and harmlessly to the environment. Additionally, PV energy systems are easy to install and financially supported by many governments, which has helped disseminate PV technology worldwide. The total generated power from PV installations (and the number of installations) has increased more than two-fold during the past 3 years, so that now more than 177 GW of PV-generated power is delivered per year. Researchers have been led to work on the obstacles facing PV systems from different perspectives, including: installation cost, inconsistency, and conversion and interface efficiency. The aim of this thesis is to design a high-efficiency PV inverter system configuration. The contribution to the knowledge in this thesis can be divided into two parts. The first part contains a critical analysis of different maximum power point tracking (MPPT) techniques. The second part provides a detailed design of the inverter system, which consists of a boost converter and a low-frequency H-bridge. Together, the three parts in this contribution present a complete high efficiency PV inverter system. The proposed system maintains high-efficiency energy delivery by reducing the number of high-frequency switches, which waste a significant amount of energy and reduce system efficiency. In order to show the superiority of the proposed configuration, a power loss analysis comparison with the other existing configurations is presented. In addition, different scenarios have been simulated with Matlab/Simulink. The results of these simulations confirm the distinction of the proposed configuration as well as its low-loss, high-efficiency characteristics which is rated at 98.8%.

Satellites need a source of power throughout their missions to help them remain operational for several years. The power supplies of these satellites, provided primarily by solar arrays, must have high efficiencies and low weights in order to meet stringent design constraints. Power conversion from these arrays is required to provide robust and reliable conversion which performs optimally in varying conditions of peak power, solar flux, and occlusion conditions. Since the role of these arrays is to deliver power, one of the principle factors in achieving maximum power output from an array is tracking and holding its maximum-power point. This point, which varies with temperature, insolation, and loading conditions, must be continuously monitored in order to react to rapid changes. Until recently, the control of maximum power point tracking (MPPT) has been implemented in microcontrollers and digital signal processors (DSPs). While DSPs can provide a reasonable performance, they do not provide the advantages that field-programmable gate arrays (FPGA) chips can potentially offer to the implementation of MPPT control. In comparison to DSP implementations, FPGAs offer lower cost implementations since the functions of various components can be integrated onto the same FPGA chip as opposed to DSPs which can perform only DSP-related computations. In addition, FPGAs can provide equivalent or higher performance with the customization potential of an ASIC. Because FPGAs can be reprogrammed at any time, repairs can be performed in-situ while the system is running thus providing a high degree of robustness. Beside robustness, this reprogrammability can provide a high level of (i) flexibility that can make upgrading an MPPT control system easy by merely updating or modifying the MPPT algorithm running on the FPGA chip, and (ii) expandability that makes expanding an FPGA-based MPPT control system to handle multi-channel control. In addition, this reprogrammability provides a level of testability that DSPs cannot match by allowing the emulation of the entire MPPT control system onto the FPGA chip. This thesis proposes an FPGA-based implementation of an MPPT control system suitable for space applications. At the core of this system, the Perturb-and-observe algorithm is used to track the maximum power point. The algorithm runs on an Alera FLEX 10K FPGA chip. Additional functional blocks, such as the ADC interface, FIR filter, dither generator, and DAC interface, needed to support the MPPT control system are integrated within the same FPGA device thus streamlining the part composition of the physical prototype used to build this control system.<br>M.S.E.E.<br>Department of Electrical and Computer Engineering<br>Engineering and Computer Science<br>Electrical Engineering

The thesis is concerned with a small-scale compressed air energy storage (SS-CAES) system. Although these systems have relatively low energy density, they offer advantages of low environmental impact and ease of maintenance. The thesis focuses on solving a number of commonly known problems related to the perturb and observe (P&O) maximum power point tracking (MPPT) system for SS-CAES, including confusion under input power fluctuation conditions and operating point dither. A test rig was designed and built to be used for validation of the theoretical work. The rig comprised an air motor driving a permanent magnet DC generator whose power output is controlled by a buck converter. A speed control system was designed and implemented using a dSPACE controller. This enabled fast convergence of MPPT. Four MPPT systems were investigated. In the first system, the air motor characteristics were used to determine the operating speed corresponding to MPP for a given pressure. This was compared to a maximum efficiency point tracking (MEPT) system. Operating at the maximum power point resulted in 1% loss of efficiency compared to operating at the maximum efficiency point. But MPPT does not require an accurate model of the system that is needed for MEPT, which also requires more sensors. The second system that was investigated uses a hybrid MPPT approach that did not require a prior knowledge system model. It used the rate of change of power output with respect to the duty cycle of the buck converter as well as the change in duty cycle to avoid confusion under input power fluctuations. It also used a fine speed step in the vicinity of the MPP and a coarse speed step when the operating point was far from the MPP. Both simulation and experimental results demonstrate the efficiency of this proposed system. The third P&O MPPT system used a fuzzy logic approach which avoided confusion and eliminated operating point dither. This system was also implemented experimentally. A speed control system improved the controllable speed-range by using a buck-boost converter instead. The last MPPT system employed a hybrid P&O and incremental inductance (INC) approach to avoid confusion and eliminate operating point dither. The simulation results validate the design. Although the focus of the work is on SS-CAES, the results are generic in nature and could be applied to MPPT of other systems such as PV and wind turbine.

In grid connected photovoltaic (PV) generation systems, inverters are used to convert the generated DC voltage to an AC voltage. An additional dc-dc converter is usually connected between the PV source and the inverter for Maximum Power Point Tracking (MPPT). An iterative MPPT algorithm searches for the optimum operating point of PV cells to maximise the output power under various atmospheric conditions. It is desirable to be able to represent the dynamics of the changing PV power yield within stability studies of the AC network. Unfortunately MPPT algorithms tend to be nonlinear and/or time-varying and cannot be easily combined with linear models of other system elements. In this work a new MPPT technique is developed in order to enable linear analysis of the PV system over reasonable time scales. The new MPPT method is based on interpolation and an emulated-load control technique. Numerical analysis and simulations are employed to develop and refine the MPPT. The small-signal modelling of the MPPT technique exploits the fact that the emulated-load control technique can be linearised and that short periods of interpolation can be neglected. A small-signal PV system model for variable irradiation conditions was developed. The PV system includes a PV module, a dc-dc boost converter, the proposed controller and a variety of possible loads. The new model was verified by component-level time-domain simulations. Be cause measured signals in PV systems contain noise, it is important to assess the impact of that noise on the MPPT and design an algorithm that operates effectively in pr esence of noise. For performance assessment of the new MPPT techniques, the efficiencies of various MPPT techniques in presence of noise were compared. This comparison showed superiority of the interpolation MPPT and led to conclusions about effective use of existing MPPT methods. The new MPPT method was also experimentally tested.

Solar power is becoming ever more popular in a variety of applications. It is particularly attractive because of its abundance, renewability, and environment friendliness. Solar powered spacecraft systems have ever-expanding loads with stringent power regulation specifications. Moreover, they require a light and compact design of their power system. These constraints make the optimization of power harvest from solar arrays a critical task. Florida Power Electronics Center (FPEC) at UCF set to develop a modular fault-tolerant power system architecture for space applications. This architecture provides a number of very attractive features including Maximum Power Point Tracking (MPPT) and uniform power stress distribution across the system. MPPT is a control technique that leads the system to operate its solar sources at the point where they provide maximum power. This point constantly moves following changes in ambient operating conditions. A digital controller is setup to locate it in real time while optimizing other operating parameters. This control scheme can increase the energy yield of the system by up to 45%, and thus significantly reduces the size and weight of the designed system. The modularity of the system makes it easy to prototype and expand. It boosts its reliability and allows on-line reconfiguration and maintenance, thus reducing down-time upon faults. This thesis targets the analysis and optimization of this architecture. A new modeling technique is introduced for MPPT in practical environments, and a novel digital power stress distribution scheme is proposed in order to properly distribute peak and thermal stress and improve reliability. A 2kW four-channel prototype of the system was built and tested. Experimental results confirm the theoretical improvements, and promise great success in the field.<br>M.S.E.E.<br>Department of Electrical and Computer Engineering<br>Engineering and Computer Science<br>Electrical Engineering

This item is only available in print in the UCF Libraries. If this is your Honors Thesis, you can help us make it available online for use by researchers around the world by following the instructions on the distribution consent form at http://library.ucf<br>Bachelors<br>Engineering and Computer Science<br>Electrical Engineering

碩士<br>國立彰化師範大學<br>電機工程學系<br>98<br>This paper proposed a high- power- factor wind energy maximum power point tracking system, which is composed of three “Single Phase Power-Controlled Power Factor Correctors(PFC)” and one “Maximum Power Point Tracking Controller(MPPTC)”. With PFC and MPPTC, the proposed system can increase the power factor in the circuit and obtain the maximum energy from the three-phase wind generator. Each “Single Phase Power-Controlled Power Factor Correctors” is composed of one single-phase rectifier, one full bridge converter, and one power factor corrector (PFC) IC UC3854; and “Maximum Power Point Tracking Controller” is implemented by one microchip “HT46R24” with maximum power point tracking (MPPT) algorithm. The proposed system has advantages that modulizes the system、increases the wind generator efficiency and decreases the noise of the wind generator. At last, the proposed system will be verified by implementation of a 600W prototype As experiment results, the proposed “high- power- factor wind energy maximum power point tracking system” not only reach a high power factor at 0.98, but also operate at the mpp under different wind velocity conditions, which improves the efficiency of the wind energy system effectively.

碩士<br>國立宜蘭大學<br>電機工程學系碩士班<br>102<br>The purpose of this study is to develop solar energy control system with the functions of solar tracking and maximum power point tracking.Solar tracking system aims to track the position of the sun with the purposes of making the sun and solar panels form right-angled projection to obtain the maximization of solar energy. Solar tracking system designed in this study belongs to passive axis control system which means to control the dual-axis motor by means of longitude, latitude and time to calculate the angles of elevation and azimuth of the sun.The principles of maximum power point tracking are to adjust the duty cycle of the boost converter, aiming to change the output voltage and current of the solar cell to obtain the maximum power point. On literatures, the common maximum power point tracking method is incremental conductance.Proportion Integration Differentiation Like Fuzzy Control (PIDFC) was proposed in this research to improve the track efficiency of the maximum power point.Additionally, the conversion efficiency of the solar energy is susceptible to environmental temperature. Therefore, the temperature compensation mechanism was proposed with the purposes of adjusting dynamically the control command of the PIDFC and further achieving better power efficiency for the output power of the system. Finally, the differences between PIDFC maximum power point track control algorithm with the temperature compensation mechanism and the traditional MPPT as well as PID-MPPT were compared in this research. The results showed that system power, response time and stability were improved obviously.

碩士<br>國立成功大學<br>航空太空工程學系碩博士班<br>97<br>Due to the energy crisis, renewable energy sources have been suggested as the possible solution. Among these sources, solar energy is pollution free and inexhaustible. Therefore it is a fairly good energy to generate electric power. However, the efficiency of solar cell is still very low, for that matter how to make the photovoltaic power system works in maximum power point is important. This thesis focuses on the maximum power point tracking control of photovoltaic power system. Owing to nonlinear I-V characteristics of photovoltaic cells, a maximum power point tracking algorithm is adopted to maximize the output power. In this thesis, An approach for maximum power point tracking using the sliding mode control is proposed. The proposed controller is robust to harsh environment changes and the performance of the controller is verified through simulations.

Photo voltaic installations in urban areas operate under uneven lighting conditions. For such a system to achieve its peak efficiency,each solar panel is connected in series through a micro-converter, a dc-dc converter that performs per-panel distributed maximum power point tracking (DMPPT). Normally solar panel have lower efficiency so to maximize the efficiency of PV cell we use MPPT controller, different technique are used to maximize power of PV cell like P & O Algorithm and Extremum seeking controller etc. The objective of this thesis is to design a compensator for the DMPPT micro-converter. And observe which one is batter in performance and reliable with speed and accuracy. The output power of PV cell in generally low to make useful we use a boost converter so that voltage level increase upto certain value. A novel, systematic approach to plant modelling is presented for this system, together with a framework for characterizing the plant’s uncertainty. Finally output of boost converter is apply in inverter and observe the output with both single phase inverter and three phase inverter with 180 degree conduction mode.and design of current mode PI controller for single phase PWM inverter. The controller is comprised of inductor current as the inner loop and voltage as outer feedback loop, to evaluate the performance of the designed controller objective of this thesis is to design a compensator for the DMPPT micro-converter. The simulation of all system give the result which justify the theoretical data.

碩士<br>國立高雄應用科技大學<br>電機工程系碩士班<br>95<br>The fossil fuels have been widely used to due the fast development of the industry, and it results in the problem of the exhaustion of fossil fuels and the damage of environment. The development of renewable energy sources will be the trend from the viewpoints of protecting environment and obtaining more energy sources. Wind power is one of the important renewable energy sources. If the wind energy can be used widely and effectively, the problems of energy demand, environment pollution and greenhouse effect can be relieved. Power converter interface is one of the key technologies for the wind power generator system, and the maximum power point tracking is one of the key technologies for power converter interface of the wind power generator system. In this thesis, a maximum power point tracking method for the permanent magnet synchronous wind power generator is proposed. A prototype is developed and tested to verify the performance of the proposed maximum power point tracking method. The experimental results show that the performance of proposed method can effectively track the maximum power of the permanent magnet synchronous wind power generator.

碩士<br>中原大學<br>電機工程研究所<br>93<br>The wind-turbine generation system (WTGS) exhibits a nonlinear characteristic and thus its maximum power point varies with changing atmospheric conditions. In order to have the WTGS operate at maximum power points under different wind speeds, the thesis proposes two maximum-power-point-tracking (MPPT) control methods of the slope-comparing (SC) and the power-difference-product (PDP) algorithms to be used in the WTGS. In the thesis, load models of the WTGS under different wind speeds are first built up for design of control rules and feasibility studies of the proposed MPPT methods. Based on the traditional current-type perturbation & observation (P&O) as well as the three-point-weighting comparison (TPWC) algorithms, comparisons are made for the proposed SC and PDP methods. In the practical system implementations, the MPPT methods are integrated in the TMS320C240 digital signal processor (DSP) to adjust the duty ratios of the buck-boost converter to control the WTGS working with maximum power output. To compare and verify the effectiveness of the four MPPT control methods mentioned above, a practical WTGS has been used. The WTGS includes a small wind turbine with three 1.17m diameter blades and a three-phase, 12-pole, 100W, small permanent-magnet synchronous generator. The experimental results show that the proposed PDP controller achieves the best performance in terms of maximum power tracking capabilities among the four MPPT algorithms, though all the four MPPT algorithms can reach maximum power points in different wind-speed conditions.

碩士<br>中原大學<br>電機工程研究所<br>99<br>This report analyzes the differences of maximum power point tracking (MPPT) methods by using MATLAB simulations. Considering the small wind power system composed of a small wind turbine, permanent-magnet synchronous generator, three-phase full bridge rectifier, DC/DC converter, MPPT power controller, and load, we will find the problems for using traditional MPPT methods. Here the fuzzy logic control method as well as perturbation and observation method is utilized for the MPPT control under several cases with step, fixed, and variable speed wind. By the MATLAB simulation tests, the fuzzy logic control MPPT method is better than the perturbation and observation method.

碩士<br>國立中央大學<br>電機工程學系<br>107<br>This thesis mainly establishes a high-efficiency solar power conversion system, and cooperates with maximum power point tracking control and DC/DC boost converter with soft switching characteristics to improve the efficiency of the overall solar power generation system. The system proposed in this thesis is mainly divided into two parts. The first part is the discussion of the maximum power point tracking strategies. It analyzes the characteristics, advantages and disadvantages of various maximum power point tracking technologies. The second part is an investigation of DC/DC boost converter with soft switching characteristics to achieve maximum power point tracking and improve the input solar source to the voltage value required at the DC bus. Using zero-voltage switching technology, the voltage of the main circuit switch is first reduced to zero and then turned on to minimize the switching loss through the second auxiliary switch and the resonant circuit. The operation time of the second auxiliary switch is determined by the algorithm in the single chip to determine the best switching time. The soft-switching technology minimizes its switching loss, and combing the two parts to achieve a high-efficiency conversion system for the solar source.

碩士<br>國立彰化師範大學<br>機電工程學系<br>96<br>To improve the energy problems and environmental pollutions，the solar energy is valuable to investigate. Taiwan relies much on the energies imported，so the other energy studied is very important. Solar energy is a clean, contamination-free resource which can be inexhaustible, hence, it is focused to study in this article. the different degrees of intensity of the heat with every changing season, it is good for generating electrical power. At present, the efficiency of solar cell is quite low, how to make it to absorb maximum power from sun is very important. We designed a maximum power tracking system using two small Spv .to measure the position of sun .and we also measure the solar power at different face angles and to find out the best face angles. We analyze the effect and efficiency of the solar power system to achieve the maximum power. using different DC/AC converters，8051micro-processor, amplifier connection types and to show by LED .to start step moter or servo moter. We achieve several results in this study. Point 1: save action power. Point 2:save the fees of equipment. point 3: to suit a small type or a family type to accomplish a compact and easy-to use SPV. Keywords: Solar Power cell, 8051micro-processor, DC/AC Converter. Amplifier.

碩士<br>國立臺灣大學<br>電機工程學研究所<br>101<br>An autonomous distributed maximum power point tracking (DMPPT) photovoltaic (PV) system is proposed in this thesis. The proposed DMPPT PV system is a two-stage circuit topology, which consists of a set of series-connected micro-converters and a single-phase grid-tied inverter. The four-switch buck-boost converter (FSBBC) with three operation modes and a smooth transition method is adopted to realize the maximum power point tracking (MPPT) function for each PV module. The single-phase grid-tied inverter with bipolar sinusoidal pulse width modulation (SPWM) control and ac line current regulation are utilized to control the inverter output current and input voltage. Besides, the autonomous start-up and protection procedures are well-developed for the success of the system operation. The small-signal ac model is derived to analyze the dynamic behavior and the stability of the autonoumous PV module (APVM) which consists of a PV module and a FSBBC. Moreover, the proportion-integral-resonant (PIR) compensator is developed to compensate the 120Hz ripple voltage from the ac mains and to achieve better MPPT performances. Finally, computer simulations and hardware experimental results are presented to verify the performances of the propoed DMPPT PV system.

Photovoltaic power generation has two major problems: the conversion efficiency of existing PV modules is less and amount of power generated by PV system changes with weather conditions. Also, the PV cell I-V characteristics are non-linear due to complex relationship of voltage and current and varies with change in temperature or insolation. There is only one point on P-V or I-V curve called Maximum Power Point at which PV system operates at maximum efficiency and produces maximum output power. Failure to track MPP causes significant power loss. So, Maximum Power Point Tracking MPPT are required to operate PV system at MPP. The P&O algorithm and INC algorithm are commonly used methods to track MPP by adjusting duty cycle of DC-DC converter. The existing methods use microcontroller or DSP controller to implement MPPT algorithm.FPGA provides number of advantages over sequential machine microcontroller as FPGA does concurrent operation i.e. instructions executed continuously and simultaneously. DSP does DSP related calculation only so, with FPGA numbers number of components required are less. Also, FPGA is faster than DSP. Thus, the size of components required for power converter decreases. The MPPT algorithm is implemented on FPGA and programmed through LabVIEW. The programmed FPGA track MPP continuously.

Solar renewable energy harvesting is the demand of the century because of the huge energy requirement of the world today. India being a home to a huge population witnesses high Incident Solar radiations throughout the year. Planning has been made to produce at least 20 Gigawatts of high quality solar power by the year 2020. Energy harvested from the sun is a necessarily a valuable source but still most it part goes unutilised in Indian subcontinent although being a tropical region. The main obstacle for the wide usage of solar Photovoltaic systems is their efficiency which is very low (20-25% for single crystal 10-15% for polycrystalline and 3-5% for amorphous silicon solar cells) and high cost of manufacturing. In main objective behind the work in this thesis lies in extracting maximum harvestable power from a Photovoltaic module and use the energy for a DC application as well as the grid connection of the generated power so that the surplus power unutilised in the load can be transferred to the grid. Maximum Power Point Tracking (MPPT), use of Boost converter and the importance of bridge inverter have been the main investigation in this project. Also the grid connection along with supply to a three phase load using bridge inverter and PWM has been shown. First SIMULINK software is used to model the photovoltaic cell. Then MPPT interfacing is done with a boost converter and resistive load and finally through an inverter connected to the 3 phase grid. All simulations have been done in SIMULINK software of MATLAB

碩士<br>國立聯合大學<br>電機工程學系碩士班<br>97<br>In this paper, we study the issue of maximum power tracking control in a wind power generation system. A fuzzy maximum power point tracking (Fuzzy MPPT) control with self-tuned scaling factor is proposed to improve the tracking response of the perturbation and observation (P&O) method. As applying P&O method in maximum power point tracking, a fast tracking would result in large oscillation around the operating point. Hence one has to make a compromise between the tracking speed and the stability of operating point. The proposed method provides a means to resolve this dilemma. In addition, in response to step change in the velocity of the wind, the proposed scheme also outperforms the P&O method. This feature makes the proposed wind power generation system being more applicable. In addition, only output voltage and current, without sensing the wind velocity, rotation speed and torque of the wind turbine, are required in implementing the proposed Fuzzy MPPT, which could reduce the cost and increase applicability in practice. The performance of the proposed Fuzzy MPPT is first verified by computer simulation with MATLAB/SIMULINK software. For experimental verification, a wind power generating system with utility parallel interface is built, in which an eZdsp F28335 development kit is employed to realize the three MPPT controllers: self-tuned and fixed scaling factor Fuzzy MPPT, and P&O method. The experimental results of these MPPT controllers are documented, and comparisons are made to illustrate the feasibility and superiority of our approach.

碩士<br>淡江大學<br>航空太空工程學系碩士班<br>103<br>This thesis presents the development of an integrated computer simulation program for solar power maximum power point tracking system. The simulation framework mainly con-sists of three major parts, a PV simulation model, dynamic model of the SEPIC/Zeta/Synchronous four-switch type buck-boost converters, and fuzzy logic based maximum power point tracking algorithms. The maximum power point is achieved by con-tinuously adjust the duty ratio command for the power converter. First, we integrate the PV model and dynamic model of the converter in pure computer program. The simulation re-sults demonstrate the solar power system is feasible by using pure MATLAB computer pro-gram. Perturb and observe method, incremental conductance method, and fuzzy logic based MPPT controllers are then integrated into the simulation program. Final MATLAB based graphic user interface is designed to facilitate understanding of the MPPT system. The sys-tem can be used for both engineering and education purposes.

Solar photovoltaic (PV) systems are distributed energy sources that are an environmentally friendly and renewable source of energy. However, solar PV power fluctuates due to variations in radiation and temperature levels. Furthermore, when the solar panel is directly connected to the load, the power that is delivered is not optimal. A maximum peak power point tracker is therefore necessary for maximum efficiency. A complete PV system equipped maximum power point tracking (MPPT) system includes a solar panel, MPPT algorithm, and a DC-DC converter topology. Each subsystem is modeled and simulated in a Matlab/Simulink environment; then the whole PV system is combined with the battery load to assess the overall performance when subjected to varying weather conditions. A PV panel model of moderate complexity based on the Shockley diode equation is used to predict the electrical characteristics of the cell with regard to changes in the atmospheric parameter of irradiance and temperature. In this dissertation, five MPPT algorithms are written in Matlab m-files and investigated via simulations. The standard Perturb and Observe (PO) algorithm along with its two improved versions and the conventional Incremental Conductance (IC) algorithm, also with its two-stage improved version, are assessed under different atmospheric operating conditions. An efficient two-mode MPPT algorithm combining the incremental conductance and the modified constant voltage methods is selected from the five ones as the best model, because it provides the highest tracking efficiencies in both sunny and cloudy weather conditions when compared to other MPPT algorithms. A DC-DC converter topology and interface study between the panel and the battery load is performed. This includes the steady state and dynamic analysis of buck and boost converters and allows the researcher to choose the appropriate chopper for the current PV system. Frequency responses using the state space averaged model are obtained for both converters. They are displayed with the help of Bode and root locus methods based on their respective transfer functions. Following the simulated results displayed in Matlab environment for both choppers, an appropriate converter is selected and implemented in the present PV system. The chosen chopper is then modeled using the Simulink Power Systems toolbox and validates the design specifications. The simulated results of the complete PV system show that the performances of the PV panel using the improved two-stage MPPT algorithm provides better steady state and fast transient characteristics when compared with the conventional incremental conductance method. It yields not only a reduction in convergence time to track the maximum power point MPP, but also a significant reduction in power fluctuations around the MPP when subjected to slow and rapid solar irradiance changes.<br>Thesis (M.Sc.Eng)-University of KwaZulu-Natal, Durban, 2011.

碩士<br>國立中正大學<br>電機工程研究所<br>107<br>This thesis applies the taguchi fractional order particle swarm optimization (TFPSO) with a 2kW series buck-boost converter and TI control circuit, which is self-developed and has functions of buck and boost, as the maximum power tracker (MPPT) of the solar photovoltaic system combine with solar power prediction. No matter under ideal environmental conditions or partial shading condition(PSC), the converter can operate at maximum power point. We train parameters to be the best for MPPT on computer simulation by using Taguchi method. To verify its performance, we conducted experiment base on single- peak power curve, double-peak power curve, triple-peak power curve, quadruple-peak power curve, insolation variations, and temperature variations. Results show that the proposed TFPSO has better performance then FPSO. Considering that 2kW polycrystalline solar photovoltaic panels are prone to aging problems, Therefore, the use of convolutional neural networks (CNN) for solar power prediction, and Compare and analyze the ideal power and predicted power. Keywords：Taguchi fractional order particle swarm optimization, CNN, MPPT

碩士<br>崑山科技大學<br>電機工程研究所<br>97<br>This work implements a solar power battery energy storage system（BESS）with maximum power point tracking（MPPT）under substantial variation in temperature and intensity of illumination. The tracker was designed using the perturbation and observation method to track rapidly the maximum power point of the energy output of the solar cells. The power generation data were transmitted to computers via RS232 for analysis and a battery charger was realized using a dsPIC30F chip. The maximum power was output following photovoltaic transformation under varying intensity of illumination and the power generated by the solar cells was fed back to the lead-acid battery to supply the load.

碩士<br>國立臺灣大學<br>電子工程學研究所<br>97<br>Abstract Consciousness of environmental protection and soaring oil price spur worldwide demand for photovoltaic power systems, ranging from million K watt power plants to handy devices like notebook PC, mobile phone…. In the past years, the yearly world market growth rate for photovoltaics was an average of more than 40%, which makes it one of the fastest growing industries at present. Business analysts predict the market volume to increase to �� 40 billion in 2010. To evaluate PV system under various conditions such as environmental temperature drift or irradiance level fluctuation, we need models to fit the electrical characteristics of solar cells, and these models will be taken into our designs of the maximum power point tracking system. For different solar cell types, the I-V curves have different model parameters due to the material, manufacturing process, dimension,.. ., therefore, the solar cell equivalent models should be derived from I-V data to match solar cells’ electrical characteristics as accurately as possible. Traditional PV system maximum power point tracking, MPPT, converters are u proposed with a digital controller (MCU or DSP ) in many works. However, for low power applications, such controllers in the MPPT system are costly and the power consumption overhead is also too high. Moreover, for long term point of view, a compact MPPT device may be integrated into the PV cells/module with the advanced process technologies. In this work, we present a compact and cost-effective solar power MPPT system. A couple of op amplifiers and some logics are employed to track the maximum output power of the solar string. We simulated the proposed MPPT scheme under various conditions, and the results show that it is reliable and can track maximum power point correctly.

碩士<br>國立成功大學<br>系統及船舶機電工程學系<br>103<br>The research evaluates and compares the application of two Multivariate Maximal Power Point Tracking Methods on Distributed Photovoltaic System. These two algorithms are Steepest Descent Method and Particle Swarm Optimization (PSO). Since these types of tracking methods reduce the elements needed in distributed photovoltaic system hardware, the practical application would then reduce the cost of photovoltaic system. The paper will focus on the MPPT experiments of the stimulation systems according to different series-parallel combinations of photovoltaic system. There are two programs used to simulate systems: Multisim and Labview; in order to simulate transient changes of circuit and then further evaluate the best algorithm and hardware collocations. In addition, through tracking with various series-parallel combinations, the algorithm can achieve certain performance with different configurations. The experiment is composed of four CSSS-090A photovoltaic panels. Through different series-parallel combinations to implement both Maximum Power Point Tracking Methods, the results show that both Steepest Descent Method and Particle Swarm Optimization are able to track, and the results are close to stimulations, while the Steepest Descent Method has shown a better tracking efficiency.

碩士<br>大葉大學<br>電機工程學系碩士班<br>94<br>This thesis presents the method of maximum power point tracking (MPPT) of the photovoltaic at any operating conditions. The photovoltaic works on the maximum power point that makes the load to get high efficiency by the Boost DC/DC converter. First of all, "Perturbation and Observation method" and "Three points weighting method" are compared, and combine the both methods with their advantages. Then, add the determinative program to track photovoltaic's MPPT stably and quickly by voltage and current feedback controller. In the software, the program is written by MPLAB. In the hardware, a microprocessor (Microchip PIC16F877) is chosen in order to reduce hardware components and achieve MPPT purpose.

碩士<br>淡江大學<br>電機工程學系<br>89<br>A single chip based converter for photovoltaic (PV) to obtain maximum output power at any operating conditions is proposed in this thesis. This controller is adopted perturbation and observation method to obtain the maximum power tracking of the PV. Firstly, the output duty cycle of the converter is added a prescribed small disturbance. Then the output voltage and current of the PV are measured and used to calculate the output power. By comparison the output power among successive sampling intervals, one can determine the tendency of the output power, and use it as a performance index to adjust the duty cycle of the converter to the direction that can achieve maximum power point tracking. Since this method is very easy to be affected by the environment and causes the undesired disturbance. In order to improve this, a three points weighting compared scheme is proposed. This scheme can distinguish the undesired disturbance and reduce the sampling interval of controller properly. Through this improved control scheme, the PV can be operated in the neighborhood of the maximum power at different operating conditions. The designed methodology of the converter will be introduced in this thesis, and the effectiveness of the proposed methods will be demonstrated by some experimental results.

碩士<br>國立交通大學<br>電控工程研究所<br>100<br>A compact-size analog maximum power point tracking (AMPPT) technique is proposed in this thesis for high power efficiency in the photovoltaic (PV) system. Several MPPT techniques are studied at first to compare their pros and cons. The characteristics of solar array are introduced as well to address the difficulties when utilizing the solar energy. Combining the existing MPPT approaches, the thesis presents a fast and accurate tracking performance. The shading effect, which undermines the efficiency of solar array, is also discussed. The proposed MPPT technique can be further improved by global maximum power tracking (GMPPT) algorithm to guarantee its robustness. Here, a wide-range current multiplier, which tracks the maximum power point (MPP) in the solar power system, is implemented to detect the power slope condition of solar array. Simulation and experiment results show that the proposed MPPT technique can rapidly track the MPP with a high tracking efficiency of 97.3%. Furthermore, the proposed system can connect to the grid-connected inverter to supply AC power.

碩士<br>國立臺北科技大學<br>電能轉換與控制產業碩士專班<br>101<br>This thesis focuses on distributed PV solar power systems. Common central power generation has worse efficiency when shading effect occurs. This motivates us on distributed PV solar systems. Distributed solar power connects a boost converter on every solar module to make every solar module with maximum power point tracking (MPPT) function. This can enhance overall output power even when shading effect exists. Microprocessor Arduino is applied in this study as a system controller. The maximum power point tracking applied at this study is a combination of the Perturbation and Observation method (P&O) and the moving average method, whereby MPPT can be achieved successfully. This method only needs one controller. Hence, the quantity and the cost of controllers can be reduced. Finally, we use Zigbee module to do wireless data transmission and save the data in computer as excel file. Moreover, an LCD panel is used to display the shading position of solar modules and many other functions. Finally, experimental results show that the developed distributed structure and the MPPT method can precisely enhance solar power generation efficiency.

碩士<br>國立臺灣科技大學<br>電子工程系<br>98<br>A photovoltaic (PV) module has a nonlinear characteristic caused by a change in atmospheric condition. Therefore, maximum power point tracking (MPPT) methods are used to extract the maximum power of the PV module. The conventional method, such as perturbation and observation (P&O) and incremental conductance (INC), has drawbacks such as oscillation at the MPP during power fast tracking and power divergence under rapidly changing atmospheric condition. Thus, fuzzy logic controller (FLC) is implemented in the PV system to avoid the conventional problem. FLC method has not only fast response under rapidly changing atmospheric conditions but also small oscillation at the MPP. However, FLC presents difficulty of modification and tuning of control rules. The research shows that the FLC disadvantages can be reduced using single-fuzzy logic controller (S-FLC) without degrading performance. Furthermore, the control algorithm on DSP can be simplified. In the implementation, the MPPT system includes DSP TMS320F2808 as the controller, a boost DC/DC converter and resistive load. The experiment results prove that the S-FLC MPPT method performs similarly to the FLC MPPT method, and the expected MPPT efficiency can be achieved.

The recent upsurge in the demand of PV systems is due to the fact that they produce electric power without hampering the environment by directly converting the solar radiation into electric power. However the solar radiation never remains constant. It keeps on varying throughout the day. The need of the hour is to deliver a constant voltage to the stand-alone system of the variation in temperatures and solar insolation.Here we intend to examine a schematic to draw out maximum obtainable solar power from a PV module for use in a DC application. The concept of Maximum Power Point Tracking is to be implemented which results in appreciable increase in the efficiency of the Photovoltaic System. In this paper, a new MPPT has been developed consisting of a Buck-type dc-dc converter, which is controlled by a micro-controller based unit. Based on the non-linear characteristics of PV, these thesis designs a VSS controller to realize the maximum power output of PV arrays. Comparing to the other techniques used in the past, the use of proposed MPPT control improves the PV system performance.

碩士<br>國立中興大學<br>電機工程學系所<br>98<br>In the global trend of energy saving and carbon emission reduction, the renewable energy development and greenhouse gas reduction have become one of the important issues for world electricity supply. Owing to the geometrical conditions of Taiwan, power generation using ocean current, solar and wind energy are the most promising. However, ocean current power generation technology has not been used effectively, while wind power applications are limited due to supply instability, environmental conditions and some high cost factors. In consideration of the natural environments and technology maturity under such conditions, solar photovoltaic power generation has been proven powerful in developing alternative energy. The purpose of this thesis is dedicated to develop maximum power point tracking (MPPT) controllers for solar photovoltaic cell arrays under no shading and under wind situations. After the development of the complete model of photovoltaic cells with the thermal dynamic model, such MPPT controllers are designed using sliding mode control method, gradient decent approach and fuzzy control logics. The effectiveness and merit of the proposed MPPT controllers are exemplified by conducting several simulations via Matlab/Simulink modeling.

碩士<br>龍華科技大學<br>電機工程研究所<br>99<br>In recent centuries, the rise of industry and consciousness technology makes the Earth's surface temperature increasing, and causes serious climate changes and natural disasters. To avoid rapid depletion of energy resources and environmental deterioration, it is global trend and urgent priority to search for available clean energy sources. Since solar power technology has advantages of clean, inexhaustible and easy to acquire, it obtains more and more attention to the international and scientific community. The purpose of this paper is to compare three maximum power point tracking (MPPT) algorithms in a photovoltaic simulation system. The Matlab/Simulink is used in this paper to establish a model of photovoltaic system with MPPT function. This system is developed by combining the models of established solar module and DC-DC boost converter with the algorithms of perturbation and observation (P&O), incremental conductance (INC) and hill climbing (HC), respectively. The system will be simulated under different climate conditions and MPPT algorithms. According to the comparisons of the simulation results, it can be observed that the photovoltaic simulation system can track the maximum power accurately using the three MPPT algorithms discussed in this paper. HC MPPT algorithm possesses fast dynamic response, but P&O MPPT algorithm is well regulated PV output voltage and power than HC algorithm. Since the deterministic process of INC algorithm is more complicated than the other two algorithms, therefore, the tracking time spent by INC algorithm is also a little longer than the other two algorithms. The HC method is suitable for the cases of battery charging which doesn't need to care about the output stability, and the P&O method is more suitable for the system with sophisticated electric devices. Furthermore, the INC method is adaptable to the cases of fast changing weather conditions owing to its advantage of no misjudgment.

碩士<br>國立勤益科技大學<br>電機工程系<br>107<br>The purpose of this thesis was to develop a photovoltaic system that stores energy for use in direct current micro-grid systems or to supply electric power to consumers living in remote areas. If the photovoltaic module array is shaded, the signals of conventional maximum power point trackers (MPPT) may be trapped at local maximal power. Therefore, this thesis developed a smart maximum power point tracker to track the maximum power point (MPP). The control method adopted an improved teaching learning based optimization (TLBO) algorithm. To adjust the energy flow direction of the direct current load terminal, this thesis proposed an energy accumulation and release strategy that used a dc/dc high-boost/buck-ratio bidirectional converter to control the battery charge and discharge for energy accumulation and release. Some simulation and experimental results are made to verify the feasibility of the proposed system.

碩士<br>朝陽科技大學<br>資訊工程系碩士班<br>97<br>The averaged perturb-and-observe (P&O) maximum power point tracking (MPPT) algorithm is presented in this paper, and its main advantage is to adopt the moving average calculate of voltage and output power of solar cell. Its can reduce tracking time, swing range on maximum power point and high frequency noise. In general P&O algorithm is direct feed-back signal to controller. It is easy make the controller work not correct and algorithm fault. The averaged P&O algorithm is improved from P&O algorithm, and its main advantage is to average voltage and output power. The solar module voltage and current signal is averaged by proposed algorithm to achieved MPPT. The averaged P&O algorithm can avoided the high frequency noise, and made the system more reliability. The solar system is contains solar penal, boost dc/dc converter and MPPT controller, and simulated by using OrCAD Pspice. We simulated focus on variation current source and load of single solar module, and the simulated results are shown the efficiency of the system. The MPPT system not only reduces the swing range and tracking time but also decrease noise influenced of nature. The MPPT system can use to single, series and parallel solar modules.

碩士<br>國立成功大學<br>系統及船舶機電工程學系<br>102<br>In order to solve the problems of partial shading effect on the centralized photovoltaic system, a distributed photovoltaic system is proposed by setting up a DC-DC converter on each solar panel output terminal and a MPPT controller adjusting the reference voltage to do maximum power point tracking. In this system, even with certain panel breakdown, other panels can also operate at maximum power point. In general, a distributed photovoltaic system usually uses a high-level central controller responsible for all calculations, including the MPPT operation, PI regulation control and data collection. This research intends to use three micro-controllers designing a distributed MPPT controller which has the same function with the high-level central controller. As a result, the cost is reduced for the entire distributed PV system. Moreover, the proposed distributed MPPT controller takes advantage of the PV power directly, therefore the convenience and low price will make this work more competitive in the market. During the course of simulation, this work uses LabVIEW to simulation the control variables and also acts as a digital PV panels. For real electricity output, the solar power is generated by the Solar Array Simulator. Then the distributed MPPT controller is used to perform MPPT operation, and to test the MPPT efficiency and stability. In the experimental part, this study first uses two polysilicon photovoltaic panels to charge the lead-acid battery for system function testing. Lastly, we use eight polysilicon photovoltaic panels connecting to the power grid to test the proposed distributed photovoltaic system for a longer period of time for system stability evaluation.

碩士<br>南台科技大學<br>機械工程系<br>98<br>Due to its abundant availability, cleanness, safety, noise free and simplicity, solar energy is considered as a promising alternative energy source in the near future. The main challenges related to solar energy utilization, especially photovoltaic (PV), are concerning its high installation cost and low energy conversion efficiency. Maximum power point tracking (MPPT) is an approach that is used to optimize the utilization of PV panel, thus energy emitted from the sun can be extracted maximally. The main objective of this work is to implement some MPPT methods by using low-cost hardware. In this case, microcontroller PIC18F4431 was chosen for this purpose. Beside some widely used MPPT methods such as Perturbation & Observation (P&O) and Incremental Conductance (INC), new alternative of low-cost MPPT methods were proposed as well. They are Single-Input Fuzzy Logic Control (S-FLC) and Single-Input Cerebellar Model Articulation Control (S-CMAC). The main advantage of the use of S-FLC is reduction of number of input that results in simpler computation compared to traditional FLC, while S-CMAC can be considered as a simple form of artificial neural network-based MPPT which is more possible for lowcost hardware implementation. Some simulations in MATLAB and experiments were conducted to evaluate the performance of each method. The simulation results showed that the proposed methods could perform very well at the beginning of tracking process and also during steady state. The oscillation that occurred and become one of drawbacks of P&O can be greatly reduced and hence it can reduce power loss. In term of efficiency, the proposed methods also obtained higher efficiency than P&O. The experiment results were also in a good agreement with simulation results. The overall results showed that the proposed methods have good performance and can be considered as an alternative of low-cost MPPT methods.

碩士<br>國立臺灣科技大學<br>電機工程系<br>103<br>Photovoltaic cells exhibit nonlinear V-I characteristic curve, which vary with insolation and temperature. When partial shading occurs, there may exist multiple maximum points in the P-V characteristic. To extract the maximum power, the development of a maximum power point tracking (MPPT) system is necessary. In this thesis, we design an MPPT system with a DC-DC converter whose MPPT control algorithm is based on a meta-heuristic method, known as simulated annealing (SA). Although SA has been adapted for MPPT control in the literature, their tracking times to obtain the global maximum point are excessively long. This thesis essentially improves the existing SA methods to drastically reduce the tracking time without compromising the MPPT efficiency.

碩士<br>中原大學<br>電機工程研究所<br>105<br>The solar modules will have a number of local maximum power point under partial shading conditions, such that the traditional maximum power point tracking (MPPT) methods will lead to some local maximum power points and reduce energy conversion efficiency. In order to avoid this problem, this thesis proposes a hybrid method by combining shuffled frog leaping algorithm (SFLA) and incremental conductance method (IncCond) for a multi-module DC solar power system. In this system, a master boost converter is used as a voltage regulator for the DC load, while the other slave boost converters perform the maximum power point tracking with Arduino control board. Finally, Matlab simulation and circuit implementation are carried out to verify the proposed hybrid method to achieve the global maximum power point tracking under partial shading conditions.

碩士<br>中原大學<br>電機工程研究所<br>99<br>The purpose of this thesis is to develop a distributed maximum power tracker for a solar cell. The tracker can coordinate the maximum power point of the solar cell as following illumination condition changing. This thesis proposes a method to obtain maximum output power at all operating condition for the an application specific integrated circuit (ASIC) based converter for photovoltaic (PV) system .This controller adopts perturbation and observation method to obtain the maximum power tracking of the PV. Firstly, the output duty cycle of the converter is added a prescribed small disturbance. Then the output voltage and current of the PV are measured and used to calculate the output power. By comparing the output powers among successive sampling intervals, it can determine the tendency of the output power variation, and use the parameter as a performance index adjusting the duty cycle of the converter to achieve maximum power point tracking. An hardware scheme with software algorithm is implemented established to fulfill the design for maximum power tracking .and experimental data are collected to validate the proposed scheme.