一种新型半桥逆变器电容均压控制策略

A Novel Voltage Balance Control Strategy of Half-Bridge Inverter

传统半桥逆变电路中直流分压电容存在电压偏差,会引起输出电压和电流波形畸变,电路性能恶化,甚至导致系统失控。本文在不改变电路结构的基础上,提出了基于调制波反馈控制的电容均压控制策略,仿真和实验结果验证了该控制方法的正确性,将该控制策略运用到EPS(EmergencyPowerSupply)系统中,有效地消除了直流分压电容电压偏差。

A general problem in the half-bridge inverter is the voltage unbalance of the dc-link capacitors. This unbalance distorts the waveforms of the output voltage and current. Furthermore, it will lead to instability of the inverter system. Based on the detailed analysis for the unbalance problem, a novel half-bridge control strategy is proposed in this paper. The method avoids sensing the voltages of the dc-link capacitors and adding extra circuit. Simulation and experimental results on a 10 kW EPS system verify the theoretical analysis.