A New Modular Micro-inverter with Sinusoidal Output Voltage Using GaN Switches for PV Modules

A new Interconnected Modular Multilevel Converter (IMMC) for photovoltaic (PV) applications is proposed in this paper. The proposed IMMC is a high power density converter that produces a sinusoidal output voltage. The sinusoidal output voltage and high power density of the converter makes it suitable to be proposed as a micro-inverter for PV applications. The IMMC has the following advantages: low EMI; sinusoidal output voltage; low voltage GaN switches can be employed due to its multilevel structure. The proposed system is modular in construction employing high frequency L-C components. Simulation results of a single-phase grid-connected IMMC micro-inverter including the Maximum Power Point Tracking (MPPT) operation and grid-tie control. Experimental results are presented to demonstrate the feasibility of the proposed micro-inverter.