三相Vienna整流器的不连续空间矢量脉宽调制及电压谐波分析方法

Discontinuous Pulse Width Modulation and Voltage Harmonic Analysis Method for Three-phase Vienna-type Rectifiers

研究一种兼顾低开关损耗和中点电位平衡的三相Vienna整流器不连续空间矢量优化调制方式,通过冗余钳位模式来调节中点电位,给出冗余钳位模式和矢量作用序列选择依据。提出一种适用于三电平调制的新型谐波分析算法,将傅里叶分析与数字控制的思想相结合,通过分段累加的方式分析三电平调制的交流侧电压谐波含量。最后,搭建一台10kW的三相Vienna整流器样机,验证了所提调制方式可以兼顾中点电位平衡和低开关损耗,与空间矢量脉宽调制(space vector pulse width modulation,SVPWM)相比提高了效率,并仿真验证所提谐波分析算法的准确性。

An optimized discontinuous space vector pulse width modulation(DPWM) scheme was studied with the advantages of low switching losses and neutral-point(NP) voltage balance capability. The NP voltage was regulated by redundant clamping modes, and both of the redundant clamping modes and switching states sequence were presented. Moreover, a novel Fourier analysis algorithm was proposed for the three-level modulation scheme. The proposed harmonic analysis algorithm was based on the combination of digital control and Fourier analysis. The AC side voltage harmonics was calculated by the way of piecewise accumulation. Finally, a 10 kW three-phase Vienna-type rectifier prototype was built. Experimental results show that the proposed scheme can regulate the NP voltage balance effectively, and the efficiency of the proposed DPWM is higher than that of the conventional SVPWM. Further, the accuracy of the proposed voltage harmonic analysis algorithm was verified by simulation results.