Design of a 21‐Level Wide‐Frequency Range High‐Voltage Arbitrary Waveform Generator

ABSTRACT This paper designs a 21‐level high‐voltage arbitrary waveform generator based on the cascaded H‐bridge (CHB) topology, capable of outputting frequencies from 1 kHz to 1 MHz and achieving an output voltage of up to 6 kV with customizable waveforms. A primary disadvantage of CHB multilevel converters is the need for multiple isolated DC sources. To overcome this, the paper proposes a solution that employs a series‐connected transformer to provide the necessary isolated supplies and a balanced discharge method across different levels of CHB to minimize the voltage difference between the supporting capacitors at each level. Additionally, to reduce switching losses and maintain the output waveform frequency in sync with the switching frequency, a nonmodulating pulse width modulation ( PWM) control method is used, which can achieve efficiencies up to 97%. The paper provides a detailed introduction to the circuit structure, control strategy, parameter design approach, and efficiency analysis of this arbitrary waveform generator. The superior performance of the proposed 21‐level high‐voltage arbitrary waveform generator is validated through simulations and testing of a prototype with a rated output power of 4 kW.