Design Of Single Phase Isolated Push-pull Photovoltaic Inverter

Solar energy resource,as one of the most environmentally friendly and safe new energy sources,has received more and more experts’ attention and in-depth research in recent years.As one of the most critical equipment in the solar power generation system,the performance of the photovoltaic inverter is directly related to the conversion efficiency between the solar energy resources and the output energy.Studying the structure and control algorithm of photovoltaic inverter is one of the important steps to improve the efficiency of photovoltaic energy conversion.In this paper,we design a single phase isolated type push-pull photovoltaic inverter,this paper through the analysis and comparison the photovoltaic inverter common booster,inverter,filtering circuit topological structure at all levels,USES determines the push-pull is type DC-DC booster circuit,full bridge DC-AC inverter circuit and LC filter as photovoltaic inverter main circuit topology.Through modeling and simulation of solar cells,the principle of maximum power tracking point(MPPT)and common algorithms are introduced.Particle swarm intelligence algorithm is used to improve the traditional algorithm,and MATLAB modeling and simulation are used to verify the speed and efficiency of the improved algorithm.In this design,STM32F103C8T6 chip is used as the main control chip of photovoltaic inverter.According to the topological circuits at all levels,the parameters of components are calculated and selected,and the main circuit of the inverter is designed.Sampling circuit,driving circuit,auxiliary power circuit and protection circuit are designed according to the designed main circuit.After the inverter circuit schematic diagram is designed,the prototype PCB board is designed.After the inverter software program design,including inverter main program design,ADC sampling,A/D conversion program design,each circuit driver program design and MPPT algorithm program.Finally,the designed inverter prototype was debugged with hardware and software.The driving waveform and output power quality of the inverter prototype were analyzed and verified through the simulation experimental platform built in the laboratory.The structure shows that the prototype inverter meets the design requirements.