UPQC: An Exhaustive Solution to Improve Power Quality

To improve power quality in the distribution system, various custom power devices like dynamic voltage restorer (DVR), distribution static synchronous compensator (D-STATCOM), and unified power quality conditioner (UPQC) are used. DVR takes care of voltage related problems viz. voltage sag, swell, interruption. D-STATCOM either generates or absorbs the reactive current and provides reactive power compensation. So, DVR and D-STATCOM can handle either voltage related problems or current related problems and they don't filter the harmonics. For that active or passive filters are installed. But UPQC can tackle the current and voltage related power quality issues and also filter the harmonics. So, there is no need to install so many devices in the distribution system to alleviate power quality issues and UPQC can be considered as an exhaustive solution. In this paper, UPQC is introduced as an exhaustive device to improve power quality with its working principle. The design and control of series and shunt compensator of UPQC have been done with the help of reference frame (dq) theory. The simulation of UPQC, its series, and shunt compensator have been done in the PSIM environment. FFT analysis of results is also shown to clarify the results.