Study On Small Power Photovoltaic Inverter

Photovoltaic inverter, which can transform DC power generated by photovoltaic panels to AC power, is an important part of photovoltaic (stand, grid-connected) power system.This thesis comprehensively analyzed the state of the art of inverter technology, particularly studied the topological structure of inverter. To meet the demand of small size, high efficiency principle, the paper designed a kind of small power inverter adopted high-frequency boost converter and full-bridge inverter mode. Then, computer simulation of the determined solution was carried out. The DC booster adopted the PWM controlled push-pull converter, which was equivalent to switching power supply. The converter achieves the advantages of simple structure, low components requirement. DSP is used in the inverter as the SPWM producer. And the full-bridge, which is the main topology, was composed of four power MOSFETs. The control unit introduced PI control strategy, which reduced the system harmonic component and improved the output waveform quality.Simulation was carried out using PowerSim, and then a prototype was designed according to the achieved scheme and the simulation results. The experiment waveform and the measured data in Lab show that the controlling scheme is correct and the design is reasonable, reaching the state grid standard.