一种基于零矢量调节的五桥臂逆变器调制方法

A Modulation Method for a Five-Leg-Inverter Based on the Zero Vector Adjustment

针对五桥臂逆变器传统调制方法存在的电压利用率低、有大量电压反向脉冲、开关损耗大等问题,提出一种基于零矢量调节的调制方法,该方法借鉴空间矢量脉宽调制(SVPWM)技术,通过调节整合两逆变器的零矢量分布,统合考虑公共桥臂脉宽需求,使其同时满足两台交流电机的需求。仿真和实验结果表明,该方法能实现两台交流电机在不同转速下的独立控制,且与传统调制方法相比,逆变器的电压利用率可提高一倍,电压反向脉冲和一个采样周期内开关动作次数均显著减少,从而验证了所提方法的有效性。

In order to solve problems such as the low utilization ratio of voltage, a large number of voltage reverse pulse and high switching loss, caused by the conventional modulation method for the five-leg-inverter, a modulation method based on zero vector adjustments is proposed in this paper. In this method, pulse widths of voltage vectors are calculated according to space vector pulse width modulation（SVPWM） theory. The distribution of vectors is adjusted and optimized, especially the extra zero vectors are considered and inserted while the needs of the common leg for both motors collide, as a result, requirements from both motors can be satisfied at the same time. Simulation and experimental results show that both motor can operate at different speeds independently by using the proposed modulation method. Compared with the conventional half-cycle PWM method, the voltage transfer ratio of voltage increases twice, moreover, reverse voltage pulses and switching times in one sampling period are reduced effectively, which demonstrate the effectiveness of the proposed method.