Improvement of power quality using a hybrid UPQC with distributed generator

This paper proposed a reduced rating star-connected transformer based unified power quality conditioner with distributed generator for power quality improvement. This work comprises of a three phase three wire UPQC, star connected transformer and LC filter. This hybrid approach significantly improves the performance of UPQC under unbalance source voltage condition. The UPQC adopted to compensate current and voltage-quality problems of sensitive loads and suppressing the load current harmonics under distorted supply conditions. The dc link control strategy is based on the fuzzy-logic controller. The proposed solution has analyzed and described, and a model of a 500-kVA grid is considered. The extensive simulation results have carried out in MATLAB/SIMULINK environment power system blockset toolboxes. From the results it has shown that hybrid UPQC with DG achieves superior capability of mitigating the effects of voltage sag/swell and suppressing the load current harmonics, phase current harmonics and neutral current under distorted supply conditions. To validate the results produced by the proposed method, it is compared with the conventional UPQC method and better results obtained from the hybrid approach.