基于SVPWM技术的单相多电平逆变器均压策略研究

Capacitor Voltage Balancing Strategy Based on SVPWM Technology for Single-Phase Mutil-Level Inverters

多电平逆变器存在直流侧分压电容不均压问题,这会引起输出电压和电流波形畸变,使电路性能恶化或系统失控,甚至导致电平数跌落,使其失去多电平逆变器原有的诸多优点。本文分析了单相三电平正激隔离逆变器的直流侧不均压问题,并提出一种基于单相SV。PWM技术的均压策略。该均压策略不增加原逆变器拓扑复杂度,仅在SVPWM控制中加入判断环节,即可实现分压电容均压目的。最后经仿真实验验证了该均压策略可靠性,仿真实验在Power Simulation环境下进行。

DC capacitor voltage unbalance causes the distortion of output voltage wave and the degenerate of voltage levels in multi-lever inverters. This issue of single- phase three-level inverter is analyzed and a voltage balancing control strategy based on single-phase SVPWM is proposed. This control strategy realizes the voltage balancing without any auxiliary circuit by choosing switching patterns and deciding their duration appropriately. The reliability and validity of this control strategy have been verified by the simulation results which carried in the Power Simulation environment.