Modulation Strategy and Controller for Grid-Tied Trinary Hybrid Multilevel Inverter

This article deals with the modulation and control of a trinary hybrid multilevel inverter (THMI), which is a cascade multilevel converter that maximizes the number of levels per full-bridge. The modulation presented defines the duty cycle of switches as piecewise functions of the desired output voltage, minimizing the processing time. In order to control this converter, it is modeled as a linear system with bounded disturbance. A quasi-sliding mode control (QSMC) is designed, simulated, and experimentally verified for the THMI operating in grid-tie mode obtaining better results when compared to a classic proportional-integral (PI) controller.