Method for ZVS Implementation in High‐Voltage Arbitrary Waveform Generators Based on CHB Topology

This paper introduces a novel approach to achieve ZVS without an auxiliary resonant circuit when using the CHB topology for arbitrary waveform generation. Existing CHB‐based arbitrary waveform generators typically employ hard switching and carrier‐based drive signals, with switching frequencies significantly higher than the output frequency, leading to lower efficiency. To mitigate switching losses, this paper employs a nonmodulation method to generate the CHB drive signal, aligning the switching frequency with the output waveform frequency. By setting an appropriate asymmetric dead time, half of the MOSFETs in the CHB can achieve ZVS. The paper details the ZVS implementation principle, dead time calculation, and drive signal generation scheme and validates the proposed approach through simulation and experimentation. Two types of SiC MOSFETs were used to design 21‐level arbitrary waveform generator prototypes, and efficiency comparisons were conducted for output frequencies ranging from 1 to 1000 kHz, offering design guidance for high‐voltage, low‐current applications. Experimental results demonstrate that the proposed ZVS method can enhance the overall efficiency of the power supply by approximately 4% for output frequencies below 100 kHz.