ENF Based Control for PV System Under Distorted Grid Condition

This paper deals with the control algorithm based upon an enhancement in notch filter (NF) applied to a grid connected single stage solar photovoltaic (PV) system during odd circumstances such as grid voltage distortions, PV insolation variation and fluctuation in the grid voltage etc. The enhanced-notch-filter (ENF) control extracts the positive sequence components from the grid voltages during voltage distortions and direct current (DC) offset. In single stage PV array system, during transients in the system, a Proportional-Integral (PI) controller with fixed gain doesn't give the suitable response. Therefore, a fuzzy based tuning of PI controller gains is implemented in order to overpower the shortcomings of the fixed gain PI controller. The voltage source converter provides the PV power to the grid. Tests are performed at different dynamic situations on a prototype for the validation of the system performance.