考虑中性点电位的三电平虚拟空间矢量窄脉冲抑制

Narrow Pulse Suppression of Three-Level Virtual Space VectorConsidering Neutral-Point Voltage Balancing

三电平逆变器虚拟空间矢量脉宽调制(VSVPWM)应用广泛,但由于是三电平控制,在某些区域会产生窄脉冲,从而带来不必要的开关损耗和热量积累。分析了VSVPWM的窄脉冲分布,利用差模电压和共模电压对窄脉冲进行了抑制,同时将中性点电位控制在小范围内波动。仿真和试验证明了该方法能够抑制绝大部分窄脉冲,并且不会造成输出波形畸变和谐波增加。

Virtual space vector pulse width modulation(VSVPWM)of three-level inverter is widely used.But due to the three-level inverter control,narrow pulses are generated in certain region,which results in unnecessary switching loss and heat accumulation.The narrow pulse distribution of VSVPWM is analyzed,and the narrow pulses are suppressed by the injection of the differential mode voltage and the common mode voltage with the neutral-point voltage controlled within a small range.Simulation and experiment prove that the proposed method can suppress most of the narrow pulses without causing distortion of the output waveform and increase of harmonics.