Implementation of Control Strategy for Three Phase Grid Connected System with Distributed Generation Inverters

Abstract

Currently distributed generation systems are extensivelyinhabiting there place in the power generation.Gridcodes from the transmission system operatorspronounce the behaviour of the energy source,regulating voltage limits and reactive powerinjection to remain connected and supports the gridunder fault. Happening the basis that unlike kinds ofvoltage sags require different voltage supportstrategies, a flexible control scheme for three phasegrid-connected inverter is proposed here. For thethree phase balanced voltage sags, the invertershould inject reactive power in order to raise thevoltage in all phases. In one-phase or two-phasefaults, the main concern of the DG inverter is toequalize voltages by reducing the negativesymmetric sequence and clear the phase jump. Owingto system boundaries, a balance between these twoextreme policies is mandatory. Thus, over voltageand under voltage can be avoided, and the proposedcontrol scheme prevents disconnection whileachieving the desired voltage support service. Thechief contribution of this work is the introductionof a control algorithm for reference currentgeneration that provides flexible voltage supportunder grid faults.