Three-Phase Five-Level Grid Synchronized PV Inverter with MPPT for Micro-Grid Application

This paper develops an interesting converter for three phase grid interface for photovoltaic panels. Here a new topology having least number of power semiconductor switches in the five level category is used. The converter consists of three basic sections viz. the photovoltaic source, a two phase inverter and a Scott-T transformer that converts the two-phase inverter output to three phases and connects to the grid. The control system is in the d-q reference frame which provides fast dynamic control response. A maximum power point tracking mechanism (MPPT) is used to generate the direct axis current reference in order to inject the maximum available power into the grid for any insolation. The converter has been designed and developed for 1kW. This is also experimentally validated.