Research Of 3KW Hybrid Photovoltaic Inverter

Today the petrochemical energy is decreasing and the ecological environment is being destructed. Renewable energy such as solar energy is becoming a hot issue. The hybrid photovoltaic inverter designed in this article has the advantages of both grid-connected mode and off-grid mode. It can work in grid-connected mode, off-grid mode or downtime mode and switch each other between the three models. Equipped with energy storage device, the hybrid photovoltaic inverter can also provide users with electricity whether in normal..abnormal, or the night. The main contents of this article are as follows.1、The research background, the grid-connected photovoltaic inverter and off-grid photovoltaic inverter working principle are introduced in this article.2、The hardware circuit of the hybrid photovoltaic inverter is designed in this article, including main circuit, control circuit, sampling circuit, drive circuit and protect circuit, liquid crystal display circuit, communication circuit and so on. The PCB drawing and debugging are both completed.3、The flow chart of software is designed and the control software is also written. The off-grid mode, grid-connected mode downtime mode and the judgment of the conditions of the switching method are studied in this article. The intermittent reactive power perturbation method is selected to detect island. The simulation is built and the simulation results show that this kind of detection method is more reliable, the non-detection zone is smaller, and the pollution to grid is also smaller.4、The experimental prototype is developed and it adopts two levels of structure. The experimental prototype uses TMS320F2808 as its main control chip. The related experiments are conducted in laboratory and experimental waveforms are given.