Power Quality Improvement of GridInterconnection of renewable Energy Based Distribution System

Abstract

Renewable energy resources (RES) are being increasinglyconnected in distribution systems utilizing power electronicconverters. This paper presents a novel control strategy forachieving maximum benefits from these grid-interfacing inverterswhen installed in 3-phase 4-wire distribution systems. The inverteris controlled to perform as a multi-function device by incorporatingactive power filter functionality. The inverter can thus beutilized as: 1) power converter to inject power generated fromRES to the grid, and 2) shunt APF to compensate current unbalance,load current harmonics, load reactive power demand andload neutral current. All of these functions may be accomplishedeither individually or simultaneously. With such a control, thecombination of grid-interfacing inverter and the 3-phase 4-wirelinear/non-linear unbalanced load at point of common couplingappears as balanced linear load to the grid. This new controlconcept is demonstrated with extensive MATLAB/Simulink simulationstudies and validated through digital signal processor-basedlaboratory experimental results.