并联逆变器变开关频率交错零矢量PWM方法

Variable Switching Frequency Interleaved Zero-vector PWM Scheme for Paralleled Inverters

零序环流抑制是交错并联逆变器正常运行的一个关键技术问题,过大的零序环流峰值将会增大开关管的电流应力,降低系统效率。该文在传统交错空间矢量调制的基础上,提出一种变开关频率交错零矢量脉冲宽度调制(pulse width modulation,PWM)方法。建立交错零矢量PWM的零序环流时域模型,分析输出电流纹波特性以及电气参数差异对环流特性的影响。在保证最大零序环流峰值不变且输出电流纹波满足系统要求的前提下,引入变开关频率控制,并给出变开关频率交错零矢量PWM的实现方式。最后,实验验证所提方法的有效性。

The suppression of zero-sequence circulating current(ZSCC)is a critical issue for normal operation of interleaved inverter.Larger ZSCC will increase the current stress of power switches and reduce the system efficiency.Based on the conventional interleaved SVPWM(ISVM),this paper proposed a variable switching frequency interleaved zero vector PWM scheme.The ZSCC time-domain model,output current ripple characteristics and the influence of parameters mismatch on the ZSCC were established and analyzed with the proposed scheme.On the premise that the maximum ZSCC peak value remains unchanged and output current ripple meets the system requirements,variable switching frequency control interleaved zero vector PWM scheme was introduced,and the implementation of the method was further given.Finally,detailed experimental results were provided to validate the proposed method.