准Z源逆变器的小波调制方法

提出一种适用于准Z源逆变器的小波调制策略,通过改变传统小波调制采样点位置,增大直通占空比的调节范围.将直通矢量分为两等份,分别插入采样时刻两端,使其不需额外增加开关频率,且理论上可获得最大恒定直通占空比.对所提小波调制与两种传统准Z源逆变器调制策略进行比较,对准Z源逆变器不同调制策略的升压能力、效率、谐波、调制比进行了系统的理论分析,最后通过仿真对所提方法进行验证.理论与仿真均表明,所提小波调制具有谐波小、电压利用率高、升压能力强等优点.

A wavelet modulation method for a quasi-Z-source inverter

A wavelet modulation strategy applied to a quasi-Z-source inverter was proposed. The regulating range of the shoot-through duty ratio could be increased by changing the locations of the sampling points set using traditional wavelet-modulation. The proposed modulation strategy divided the shoot-through zero vector into two portions, which were then individually inserted into both ends of the sampling time. Under the proposed strategy, the quasi-Z-source inverter could obtain a theoretical maximum constant shoot-through duty ratio without any extra switching frequencies. In addition, the proposed strategy was compared with traditional mod-ulation strategies used in quasi-Z-source inverters. The boosting capacity, efficiency, harmonic and modulation ratio of the different modulation strategies for quasi-Z-source inverter were analyzed thoroughly. Finally, the performance of the proposed method was veri-fied by simulation. Both the simulation results and theory verify that the strategy can reduce harmonic, increase voltage utilization rate, and enhance the boosting capacity.