三相Vienna整流器的载波断续脉宽调制优化算法

Optimized Carrier-based Discontinuous PWM Schemes for Three-phase Vienna-type Rectifiers

文中以三相Vienna整流器为对象,提出过零箝位型和峰值箝位型两种改进载波断续脉宽调制(optimized carrierbased discontinuous PWM,OCB-DPWM)策略。通过判断三相正弦调制波瞬时值中间值的正负号及三相正弦调制波最值,即可合成所需注入的零序分量,简化了零序分量的计算步骤。分析所提两种OCB-DPWM策略与其对应的空间矢量DPWM策略的等效性。最后,搭建一台10kW的三相Vienna整流器样机,验证所提两种OCB-DPWM策略的正确性。实验表明:OCB-DPWM1具有更优的THD性能,OCB-DPWM2具有更高的变换效率。此外,相对于传统CB-DPWM1和SV-DPWM2,所提两种OCB-DPWM算法可大幅缩短程序运行时间。

Two optimized carrier-based discontinuous PWM(OCB-DPWM)schemes,including zero-crossing clamping type and peak clamping type,were proposed.By identifying the sign of the median value of the three-phase sinusoidal modulation signals and the maximal and minimal value of the intermediary variable,the zero-sequence components(ZSCs)could be calculated directly.Thus,the calculation process of ZSCs was simplified.The equivalence between the proposed two OCB-DPWM schemes and their corresponding space-vector DPWM(SV-DPWM)schemes were analyzed.Finally,a 10kW three-phase Vienna-type rectifier prototype was built to verify the correctness of the proposed OCB-DPWM schemes.Experimental results show that the OCB-DPWM1 scheme has lower THD performance,and the OCB-DPWM2 scheme has higher efficiency.Compared with the conventional CB-DPWM1 and SV-DPWM2,the proposed OCB-DPWM schemes can greatly shorten the program execution time in digital control.