Design and Implementation of the High-Efficiency Hybrid PV Power System

• Main Authors: Neng-Yi Chu, 朱能億
• Other Authors: Liang-Rui Chen
• Format: Others
• Language: zh-TW
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/39778736890499410202

博士 === 國立臺灣科技大學 === 電機工程系 === 102 === This dissertation proposes two hybrid PV power systems which increases the power efficiency of the PV power system. They are current-sharing PV power system with ripple reducing and cascaded module integrated PV power system, respectively. In this dissertation, first, we are discussing the power efficiency effect of the PV modules affected by the PV modules construction and the low-frequency ripple current of the dc/ac inverter. Addition, we are discussing the operation principle of the battery balance circuit. To learn about the direction of the hybrid solar power system can be improved the current. Next, the circuit operation principle, design considerations of each proposed system are all detailed in this dissertation. Finally, the experimental results were confirmed in the proposed system to enhance the efficiency of power generation with the overall hybrid PV power system and stability of the power supply system. The major features of the two proposed system are summarized as follows: Current-sharing PV power system with ripple reduction is mainly constructed by a series-connected PV module, which is parallel with a bidirectional dc/dc converter. By controlling the compensation current of the bidirectional dc/dc converter, the system can really track the maximum power point of the PV module, regulate the output load energy and reduce current ripple at the same time. In this dissertation, the small signal of the proposed system is derived. By the bode plot, the stability of the proposed system can be verified. The lead compensator is used to reduce the current ripple compensation error and improve the response speed of the system. Finally, a 1200W prototype is implemented to verify the performance and the advantage. From experiment result, the proposed system can track the maximum power point of the PV module, improving the stability of the proposed system. Addition, the output current ripple of the PV module can be reduced to 3% of the tradition PV power system. The power efficiency of the PV modules is increased. Cascaded module integrated PV power system is composed of cascaded module integrated construction which can increase the power efficiency of the PV power system and multilevel inverter with battery balancing. The battery balance and reduction the harmonics component of the output ac voltage controlled by the combination of the discharge battery and conduction angle of the multi-level inverter. a prototype is realized to verify the feasibility and advantage by Simulink simulation and a 1kW prototype is implemented to verify the performance of the proposed system. From the simulation and experimental result, we can obtain that the proposed system can control the discharge period of each battery cell of the system, so that the battery balance function can be realized. At the same time, the base frequency voltage of the AC output is limited between 110V ±8%, and the 3rd. and 5th. harmonics are suppressed. Therefore, the output power quality can be improved. Besides, this paper uses the small capacity battery to verify the battery aging experiments. From the experimental result, comparing with the traditional inverter without battery balance function, the proposed system can be improved the battery energy usage by 39.3%, and the working time of the system can be extended 1.405 times.