Experimental verification of a multi-level inverter with H-bridge clamp circuit for single-phase three-wire grid connection

A multilevel inverter with a H-bridge clamp circuit is proposed for single-phase three-wire (1P3W) utility connected applications such as PV systems. The proposed inverter consists of two n-level inverters and a H-bridge clamp circuit. The proposed inverter requires only 12 controllable switches to obtain a 5-level output voltage though conventional multi-level converters with grounded neutral point of the DC-bus require 16 switches. The control strategy for the proposed circuit is also discussed in this paper. Moreover, a numerical parameter design method is established and then verified by experiments. Finally, the grid connected operation is presented by experimental results.