Three-Level PWM Inverter Based on the Battery Discharge System

Three-level PWM rectifier is suitable for medium voltage and high power with unity power factor, bidirectional power applications. This paper put forward a power accumulator battery charge/discharge system based on the three-level inverter and a AC filter design method differ from the traditional way. Because the voltage source PWM converter is rooted from the boost circuit, the topology of both its DC side and AC side is vital for its performance, the additional filter of the system should not alter the main topology of the converter. According to the standard of input current harmonic limit, a corresponding filter design method based on Fourier analysis is proposed, and the simulation of the second unit three-level charging/discharging system is established. Simulation results showed that the filter design method is feasible and the system can work with low current ripples and high power factor.