Simulation of Charge-Discharge Control Strategy of Bi-directional Inverter in Grid-Connected Mode

Bi-directional inverter is a device, which can be used in charging or discharging battery in a wind-solar-diesel hybrid power system based on pure AC bus. In this paper, through the study on charge-discharge control of bi-directional inverter in grid-connected mode, the double-loop control strategy has been used. And considering the effects of grid voltage fluctuation and load switching on voltage and current in the process of charge-discharge, the fuzzy control is introduced in the control system to improve the performance of the disturbance rejection and reliability and extend battery service life. The feasibility and validity of this control strategy are proved by simulating.