A novel controller for a grid connected single phase PV system and its real time implementation

This paper presents a novel control philosophy for active and reactive power control of a single phase rooftop photovoltaic (PV) module connected to the grid based on a proportional along with sinusoidal signal integrator controller. For locking the inverter with the grid, Estimation-based enhanced PLL is employed and its performance has been validated over of a 3 kW PV module with single phase H-bridge inverter having maximum power point tracking (MPPT) capability. The controller has been designed in MATLAB/Simulink and its stability has been analyzed using the Direct Method of Lyapunov´s Stability criterion. By using the parallel processing technique of Opal-RT the real time simulation for the simulated model has been carried out under variable operating conditions like varying solar irradiation, load switching and other changes in the grid voltage or frequency.