Mitigation of Power Quality Problems in Distribution System under Non Sinusoidal Supply Condition with UPQC using Mixed Mode Control Strategy
Keywords:
Unified Power, Quality Conditioner (UPQC), Active Power Filter (APF), Series Active Power Filter (SAPF), Parallel Active Power Filter (PAPF), Sinusoidal Pulse Width Modulation (SPWM), Hysteresis control, PSCAD/EMTDC.Abstract
A mixed mode control strategy for Unified Power Quality Conditioner (UPQC), which
involves no transformation, is presented and demonstrated for compensating the power
quality problems under non sinusoidal supply condition in a three phase distribution system.
UPQC is a combination of Series Active Power Filter (SAPF) and Parallel Active Power
Filter (PAPF) with a common dc link. The series compensation voltage and shunt
compensation current are controlled in the present work by SPWM switching of SAPF and
hysteresis control of PAPF respectively. Exhaustive simulation studies are carried out using
PSCAD/EMTDC to validate the performance of UPQC with mixed mode control under non
sinusoidal supply condition for compensating voltage sag, swell, unbalance in supply voltage
and the effect of sudden load change. The effectiveness of mixed mode control is confirmed by
comparing the results of hysteresis control applied to both APFs while mitigating the power
quality problems.
