Fundamental frequency modulated multilevel inverter for three-phase stand-alone photovoltaic application

This paper presents a fundamental frequency modulated multilevel inverter scheme for use with a three-phase stand-alone photovoltaic (PV) system. The system consists of four series connected PV arrays, a five-level diode-clamped multilevel inverter (DCMLI) generating fundamental modulation staircase three-phase output voltages, and a three-phase induction motor as the load. In order to validate the proposed concept, simulation studies and experimental measurements, done using a small-scale laboratory prototype, are also presented. The results show the feasibility of the fundamental switching application in three- phase stand-alone PV power systems.