Control of solar energy integrated active power filter in weak grid system

Abstract

In this work, a novel control of unified active power filter integrated with solar photovoltaic array (UAPF-PV) based on a modified symmetrical sinusoidal integrator (MSSI) is proposed. It is a three-phase four-wire single stage UAPF-PV system where the solar photovoltaic (PV) array is directly integrated with the DC-bus of UAPF-PV system. Two positive sequence extractors based on MSSI are used to extract fundamental positive sequence signals of distorted load currents and point of common coupling (PCC) voltages which are then used for generation of the reference signals for the shunt active filter and series active filter respectively. The shunt active filter maintains the grid currents balanced and sinusoidal while also extracting maximum power from PV array. The series compensator maintains load voltage sinusoidal and in phase with PCC voltage irrespective of harmonic distortions and sag in PCC voltages. The system performance is extensively analysed through Matlab Simulation under conditions of unsymmetrical loading, harmonic distortion and sag in PCC voltage and change in irradiation of solar PV array.