Boosting Nine-Level Operation of Seven-Level Hybrid-Clamped (7L-HC) Converter

Seven-level hybrid clamped topology, which is a multilevel topology proposed in recent years, is a promising solution for motor drive systems due to its capability to operate in a wide frequency range. This letter enhances its favorable features by enabling the boosting nine-level operation, i.e., producing nine output voltage levels; wherein the peak phase voltage can be four-third of the dc voltage. This operation method does not require modifications to the topology or change in the voltage stress on capacitors and power switches. Instead, only minor modifications to the modulation are applied. This leads to the increase of the ac voltage range without any cost on hardware. This method shows great potential in speed expansion of the motor drive system. Experimental results validate the feasibility and performance of this method. This letter is accompanied by a video file demonstrating the speed expansion performance of the proposed method.

Automated summary

This paper introduces a seven-level hybrid clamped topology and enhances its performance by enabling a nine-level operation. The method does not require modifications to the topology and only minor modifications to the modulation are needed to expand the speed range of the motor drive system. Experimental results demonstrate the feasibility and performance of this method.