To improve the reliability and efficiency of a T-type three-level inverter,a discontinuous pulse width modulation(DPWM) strategy is proposed to reduce the common-mode voltage while reducing the switching loss,which is also named as the RCVDPWM strategy. According to the mechanism of switching sequence in the T-type three-level topology which acts on the common-mode voltage,five DPWM clamping methods for common-mode voltage reduction are summarized. It can be found that there is at least one clamping method for common-mode voltage reduction at any modulation ratio or phase angle. For those phase angle regions where multiple clamping methods exist,the switch tube of the phase with the largest absolute value of current is preferentially selected for clamping to reduce the switching loss. Meanwhile,the proposed strategy can ensure that the DC component of neutral-point voltage is zero,and thus the neutral point shows a self-balancing capability. Experimental results verify the feasibility and effectiveness of the proposed RCVDPWM strategy.
关键词
非连续脉宽调制/开关损耗/共模电压/中性点
Key words
Discontinuous pulse width modulation(DPWM)/switching loss/common-mode voltage/neutral point
维普
万方数据