Analysis and Implementation of a 5-Level Hybrid Inverter with Reduced Switching Devices Using Phase-Shifted PWM

Abstract

The demand for high reliability and the performance-to-size ratio of multilevel inverters (MLIs) have triggered rapid growth in MLIs with the reduced number of controlled-switching devices, isolated dc sources, gate driver circuits, and voltage stress across the switching devices. However, the development of alternative MLIs away from traditional MLI mostly comes at the trade-offs amongst structural and control complexity, power loss, and industrial practicality as the number of voltage levels increase. Thus, this paper presents and analyzes a modest two-stage single-phase hybrid MLI with a high performance-to-size ratio, which generates a five-level voltage waveform across the load with a unity voltage gain, and reduced switches. In the first stage of inverter topology, the controlled-switching devices and gate drivers have been reduced by half as compared to its counterparts. Moreover, the inverter topology's advantages have been demonstrated on an experimental setup using a recently developed phase-shifted PWM strategy.