Zero-Voltage-Switching PWM Three-Level Converter with Interleaved Complementary Modulation

A novel interleaved complementary modulation strategy for zero-voltage-switching three-level (ZVS TL) converter is proposed, with which the two clamping diodes can be removed from the basic ZVS TL converter and all the advantages are kept. So the cost is saved and the reliability is enhanced. The charge balance of the flying capacitor is analyzed and a method to realize voltage balance is presented. The operation principle of the proposed control strategy is validated on a 600W prototype converter and the comparison with the basic ZVS TL converter is given.