Research on the Application of Cascaded Trans-Z-Source Inverter in Wind- Photovoltaic Hybrid Power Generation

Due to the change of external environment, wind-photovoltaic hybrid generation system faces the problem of insufficient output voltage and unstable power output. Cascaded trans-z-source inverter is z-source inverter with improved impedance network structure. Compared with the traditional inverter, it can accommodate multiple voltage sources and boost the output of the inverter system while improving the circuit efficiency. Therefore, the cascaded trans-z-source Inverter is applied in the wind-photovoltaic hybrid generation scenario. The household wind-PV hybrid generation system and different working status of the system containing working mode change logic are designed in this paper. Open and closed loop control for cascaded trans-z-source network are also proposed. The simulation results have shown that the inverter system including cascaded trans-z-source network has stable voltage output and large output voltage range. The designed inverter system takes into account the characteristics and challenges of the distributed wind-PV hybrid power generation, and to some extent solves the problems of low energy utilization efficiency, grid connection difficulty and complex inverter system structure. This can contribute to improving regional renewable energy utilization and peak-load shifting of the power grid.