Control Techniques of Packed U-Cell Multilevel Inverter: A Comprehensive Review

The importance of multilevel inverter is increasing continuously in recent decades from medium to high-level power conversion systems. Packed U-Cell MLI introduced recently is gaining increasing attention due to the reducing device count, lower THD and better power quality. Packed U-Cell has lesser number of devices to generate the same number of levels in the output voltages as compared to the other reduced device count MLI’s reported in the literature. This paper focusses on seven level PUC inverter, which has been practically realised in many works. The basic operation, along with modulation strategies reported in the literature, has been presented. The later part of the paper deals with a detailed review regarding the control strategies, their implementation, and discussion on the future scope of the said inverter topology.