A Single-Stage Power Conversion System for the PV MPPT Application

The photovoltaic generator exhibits a non-linear I-V characteristic and its maximum power point varies with solar insolation. In this paper, a single-phase single-stage inverter capable of tracking maximum power from the photovoltaic array and injecting a sinusoidal current to the load is presented. Mathematical models are formulated and then a tracking algorithm is evolved. Combined photovoltaic system simulation model with maximum power point tracking is developed in the PSIM power electronic circuit simulator. For a given solar insolation, the tracking algorithm changes the duty ratio of the inverter such that the solar cell array voltage equals to the voltage corresponding to the maximum power point and also maintains a sinusoidal voltage across the load. The tracking effectiveness is verified through simulation studies. Experimental investigations are carried out, using a dsPIC Microcontroller, and the measurement results are presented here for validity of the proposed technique.