A Multiple Improved Notch Filter Based Control for Single Stage PV System Tied to Weak Grid

Abstract-In this paper, a control scheme based on improvement in generalized integrator is implemented on a three phase single stage grid tied solar photovoltaic system with the distribution static compensator capabilities under grid abnormal conditions of voltage distortion and voltage unbalance. The photovoltaic-voltage source converter system compensates for the reactive power consumed by nonlinear load at point of common coupling provides load balancing and mitigates harmonics. The proposed multiple-improved-notch-filter based quadrature signal generator control approach extracts the load current fundamental component, independent of the grid voltage. This control has better DC offset and harmonics component rejection capability in comparison to a conventional second order generalized integrator algorithm. The perturb and observe based maximum power point tracking algorithm is applied for the extraction of maximum power from the photovoltaic array. The system is analyzed under different abnormal conditions of voltage distortions, voltages unbalance, the voltage swell, voltage sag, load currents unbalance and insolation change on a prototype developed in the laboratory. The system performance is found to be satisfactory, within limits as described in an IEEE519 standard while feeding active power to distribution network and connected loads.