Quasi-Z源逆变器特性及空间电压矢量调制研究

为了改善Z源逆变器性能以满足不同的应用,利用小信号模型分析了Quasi-Z源逆变器电容、电感参数变化对系统动态响应的影响。研究了直通零矢量被平均分成4段(SVPWM4)和6段(SVPWM6)的空间电压矢量调制策略,对比分析了两种矢量调制方法对Quasi-Z最大直通占空比、最大升压系数、最大电压增益性能等指标的影响。相比SVPWM6,SVPWM4可插入的直通零矢量能达到最大,开关电压应力小,最大电感电流纹波低,性能指标更优。最后通过仿真验证了理论分析的正确性。

Research on Quasi-Z Source Inverter Characteristics andSpace Voltage Vector Modulation

In order to improve the performance of Z-source inverters to meet different application requirements, by using small-signal model, an analysis has been made of the influence of capacitance and inductance parameters of Quasi-Z source inverters on the dynamic response of the system, followed by a research on the space voltage vector modulation (SVPWM) strategy, which divides the shoot-through vector into four segments (SVPWM4) and six segments (SVPWM6), as well as a comparison and analysis of the effects of two vector modulation methods on the maximum through duty cycle, maximum boost coefficient and maximum voltage gain performance of Quasi-Z. Compared with SVPWM6, the shoot-through zero vector of SVPWM4 is characterized with such advantages as the maximum value, a relatively small switching voltage stress, a low maximum inductance current ripple, and a better performance index. Finally, the correctness of the theoretical analysis can be verified by simulation.