Transformerless interleaving multilevel NPC inverter for photovoltaic systems

This paper proposes a transformerless multilevel NPC (Neutral Point Clamped) inverter for grid-connected photovoltaic systems, applying the concept of high power density, using Gallium Nitride power transistors and employing interleaving strategy for reducing the weight/volume of the passive filter elements. It also presented an equivalent circuit, it is possible to study the issue of ripple in output current, circulating current and inductor current. Are shown results of theoretical analysis as well as simulation results for power 1kW.