零电压开关多谐振三电平直流变换器的控制策略

零电压开关多谐振三电平直流变换器具有功率器件电压应力低、实现软开关范围宽、输出滤波器小的优点。该变换器的两只开关管采用相位差π脉冲频率调制的控制方式。该文将介绍交错控制方案的实现。在实际应用中由于控制电路和／或驱动电路有差异，使得两只分压电容不均压，该文提出一种均压方法，细微地调节开关管的关断时间，确保分压电容均压。论文最后给出实验结果，以验证上述方法的有效性。

CONTROL STRATEGY FOR ZERO-VOLTAGE-SWITCHING MULTI-RESONANT THREE-LEVEL CONVERTERS

Zero-Voltage-Switching Multi-Resonant Three-Level Converters have some advantages such as; reduced voltage stress on switches and diodes; ZVS achieved in a wider range and significantly reduced filter. This converters use the interleaved Pulse-Frequency-Modulation (PFM) control strategy. This paper presents the implementation of the interleaved PFM control strategy. Due to slight difference between the control circuits and drive circuits of the switches, there is slight difference between the duty cycles on the switches, which results in the unbalance of the voltages of the divided capacitors. This paper proposes a voltage-sharing method, which adjusts turn-off time of the switches, to ensure the voltage on the divided capacitors be balanced. The experimental results are presented to verify the effectiveness of the proposed methods.