一种新型三电平变流器中点电压平衡算法

A Three-level Converter Neutral-point Voltage Balancing Algorithm

在分析空间矢量脉宽调制(SVPWM)策略中点电压可控区域的基础上,提出一种根据允许的中点电压波动幅值适当扩展可控区域的新型混合调制策略,以进一步降低虚拟空间矢量脉宽调制(VSVPWM)算法的作用区域,从而有效降低开关频率和损耗。实验结果表明,相比以前的方案,新型混合调制策略可以很好地平衡中点电压,同时有效降低了开关次数。

The neutral-point voltage controllable area of sapce vector pulse width modulation （SVPWM） is analyzed.On this basis,a new hybrid modulation strategy is proposed,which extends the controllable area according to the all- owable neutral-point voltage fluctuation amplitude.The area of VSVPWM is contracted, so the switching frequency and loss are reduced.The experimental results show that the new hybrid modulation strategy can balance the neutral-point voltage and reduce the switching frequency effectively compared to the former methods.