Design and Implementation of a Hybrid Single T-Type Double H-Bridge Multilevel Inverter (STDH-MLI) Topology

Abstract

Multilevel inverters are proficient in achieving a high-quality staircase output voltage waveform with a lower amount of harmonic content. In this paper, a new hybrid multilevel inverter topology based on the T-type and H-bridge module is presented. The proposed topology aims to achieve a higher number of levels utilizing a lower number of switches, direct current (dc) voltage sources, and voltage stresses across different switches. The basic unit of the proposed single T-type and double H-bridge multilevel inverter (STDH-MLI) produces 15 levels at the output using three dc voltage sources. The proposed topology can be extended by connecting a larger number of dc voltage sources in the T-type section. The nearest level control (NLC) switching technique is used to generate gate pulses for switches to achieve a high-quality output voltage waveform. In addition, a simplified way to achieve NLC is also described in the paper. A detailed comparison with other similar topologies is provided to set the benchmark of the proposed topology. Finally, experimental work is carried out to validate the performance of the proposed topology.

Keywords

• H-bridge
• hybrid inverter
• multilevel inverter
• nearest level control
• pulse width modulation (PWM)
• T-type
• reduced switch count
• PLECS