非隔离三电平变换器中分压电容均压的一种方法

A METHOD TO BALANCE THE VOLTAGE OF THE DIVIDED CAPACITORS IN NON-ISOLATED THREE-LEVEL CONVERTERS RUAN

在非隔离三电平变换器中,分压电容必须是均压的,以保证开关管电压应力相等。在实际应用中,由于控制电路和/或驱动电路有差异,开关管的导通时间不完全相等,使得分压电容不均压,这样开关管电压应力不相等。为了解决这个问题,该文提出一种均压方法,它通过调整开关管的导通时间,确保分压电容均压,论文最后给出实验结果,以验证本方法的有效性。

The voltage of the divided capacitors of the non-isolated Three-Level (TL) converter should be balanced in order that the voltage stress of the switches is balanced. However, due to slight differences of the control and drive circuits, there is slight difference between the duty cycle of the switches, which results in the unbalance of the voltage of the divided capacitors. This paper proposes a method to adjust the duty cycle of the switches such that the voltage of the divided capacitors is balanced. The experimental results are presented to verify the effectiveness of the proposed method.