Reactive Power Enhancement of a PLL less PV inverter for AC Micro-grids

The Photovoltaic (PV) based distributed generators largely depend on the amount of solar power received during day time. The intermittent nature of solar insolation makes the grid-connected PV inverters to be underutilized during the day time and completely unutilized during night time. This paper presents a PLL-Iess PV inverter control strategy in which the entire inverter capacity is used as STATCOM during night time and supplies the real power requirements during the day time. The control strategy is developed to sustain voltage sag/swell conditions and regulating the voltage at the point of common coupling (PCC). The mathematical modeling and MATLAB/SIMULINK based simulations are presented under variable insolation and temperature as well as voltage sag and swell conditions to validate the proposed concept.