The Research And Development Of Photovoltaic Micro-grid Inverter

Gradual exhaustion of traditional energy sources and the deteriorating environment have seriously hampered the development of world economy, Humans have already could not wait to seek renewable green energy to replace traditional energy. The solar energy because of its clean environment and everlasting features, making solar power generation technology more and more popular with governments around the world strongly advocate support and invest in these fields.In order to maximize the use of solar energy, we should improve the efficiency of solar power generation system and the inverters, and achieve uninterrupted power supply of AC load, this dissertation proposed and designed a Photovoltaic Micro-grid inverter and the system which the energy can flow in dual directions The main contents and results of this study are as follows:(1) This dissertation analyzed the principle, research status and application of key technologies of solar power supplies apparatus.(2) The structure of dual power flow channel and the Photovoltaic Micro-grid inverter is designed. By comparing the structural characteristics of different topologies to determine the two-level voltage transformation that is first level with MPPT function and second level with ZVS phase-shifted full-bridge converter as the main topology of DC/DC channel. The backward stage is single phase full-bridge converter. The working states of the Photovoltaic Micro-grid inverter are analyzed, the hardware circuit is designed, and the main circuit components parameter calculation and selection are given. This dissertation also completed the design of isolation drive of converter, protection and signal sampling and other circuits.(3) The study of the control strategy for more than one micro-grid inverters connected in AC bus, through the phase lock loop and distributed control strategy to achieve multiple micro-grid parallel inverters phases in parallel.(4) The control system based on STM32F103ZET6 is designed, and the work process of the entire system, solar maximum power output control process, and the corresponding control program are given.(5) The Photovoltaic Micro-grid inverter apparatus prototype is manufactured, and the prototype is tested, the results indicate that the performance of the prototype has reached the design requirements.