Improvement of Power Quality Using Facts and DFACTs Devices

Abstract

Power Quality is a measure of to which extent a system supports reliable operation to its loads. A powerldisturbance involveslvoltage, current, or frequency variations. Powerldisturbanceslcan originate inlconsumer power systems, consumer loads, or the utilitylbecause of non-linearlloads, adjustable speed drives, traction drives, start of large motor loads, arc furnace, lightning etc. Typical power quality disturbances are voltage variation (voltage swelling, voltage sag) frequencylvariation & waveform distortion.DSTATCOM is used tolimprove qualitylof the powerlin the distribution systemlby using an adaptive leastlmean square basedlcontrol algorithm for a 3-phaseldistribution staticlcompensator (DSTATCOM) to mitigate multiple power quality problemslsuch as reactive power, currentlharmonics, load unbalancing, and solon with self-supportingldc bus voltage of voltagelsource converterlused as a DSTATCOM. Thelproposed control algorithmlis implemented forlthe extraction ofltuned weighted valueslof fundamental activeland reactive powerlcomponents of distortedlload currents whichlare major componentslin referencelsupply currents. DevelopedlDSTATCOM is operated underlvarious operating conditions andlits performance islfound satisfactory. Power qualitylis an issue that islbecoming increasinglylimportant tolelectricity consumers at allllevels of usage. Sensitivelequipment andlnon-linear loads arelcommon place in bothlthe industrial andldomestic environmentland disturbanceslcan originate fromlthese loads whichlincludes non-linearlloads like adjustablelspeed drives, tractionldrives, starting of largelinduction motor etc., typical powerlquality disturbancelare voltage fluctuation, flickering, sag, swellland spikeslin waveforms, harmonicldistortion and unbalance.