Fault Ride-Through Operation of Grid Interfaced Solar PV System with Power Quality Improvement

Abstract

This treatise proposes a generalized integrator (GI) based control scheme for low voltage ride-through operation of solar photovoltaic array (SPVA) with power quality (PQ) improvement features in the distribution grid. Under balanced/unbalanced grid voltage faults, the proposed strategy controls DC-DC converter in such a way that voltage source converter (VSC) currents are achieved within its permissible limits. Moreover, according to the recommended by the revised IEEE 1547.4 standard, the SPVA coupled VSC is adaptively supplied reactive power to the grid based on depth of grid voltage sag. The GI algorithm is proposed here to estimate accurate fundamental load component (FLC) even under the presence of DC offset. Moreover, the effectiveness of the GI algorithm is illustrated with frequency domain analysis and Lissajous plot to extract FLC. Simulation results are exhibited to illustrate the capability of the proposed strategy for the line to ground fault in the grid side network. Experimental results demonstrate the satisfactory performance under various cases such as load currents imbalancing, a variation of irradiations, SPVA-DSTATCOM mode and line to ground fault.