Author : Priyanka Chhabra

Modern power utilities have to respond to a number of challenges such as growth of electricity demand especially in non-linear loads in power grids, consequently, some policies about the power with a higher quality should be considered. This paper deals with conceptual study of power quality improvements methods used to mitigate the voltage sag, swell, voltage dip suppression and removal of harmonics distortion like UPFC (Unified Power Flow Controller)which works to improve the power quality at demand side by power conditionings for harmonic elimination and simultaneous compensation of voltage and current, which improves the power quality offered for other harmonic sensitive loads, DPFC (Distributed power flow controller) is used to mitigate the voltage deviation and improve power quality. (UPQC) unified power quality conditioner for harmonic elimination and simultaneous compensation of voltage and current, which improves the power quality offered for other harmonic sensitive loads. DSTATCOM (Static Synchronous Reactive Compensator) is a shunt connected compensator to absorb or supply reactive current against voltage disturbances such as voltage sag, swell and flicker. DVR (Dynamic Voltage Restorer) is used for improving power quality & reduce the harmonics distortion of sensitive load. DVR Proposed not only to improve PQ but also to reduce HD due to the presence of non-linear load. Combined system constructed by Shunt Active Power Filter (SAPF) and Static Var Compensator (SVC) to improve the power Quality of the island microgrid, in which SAPF uses the positive sequence method for harmonic detection.

Keywords: Power Quality, Distribution System, Sag, Swell .Unified Power Quality Conditioner (UPQC), DPFC (Distributed power flow controller harmonics, active power filter, power quality. Microgrid, power quality, PQ control method; SAPF; SVC; positive sequence method FACTS, custom power and power quality, mitigation, DVR (Dynamic Voltage Restorer)

Article published in International Journal of Current  Engineering  and Technology, Vol.3,No.2 (June- 2013)