Performance analysis of unified power quality conditioner under different power quality issues using d-q based control

Utility has to supply quality power to all consumers. electrical equipment like compressors and pumps take heavy inrush of current during starting,causing voltage sag/swell. on the other hand,usage of electric drives and switch mode power supplies generate harmonics in the supply system. in this paper,synchronous reference frame (srf) control applied to unified power quality conditioner (upqc) is presented to regulate the load voltage and supply currents against supply voltage distortion,voltage sag/swell under non-linear and unbalanced loads. using matlab/ simulink,a three-phase four wire system under distorted voltage supply,voltage sag/swell and unbalanced non-linear load was developed. active and reactive power flow analysis is also investigated in this study. capacitor voltage balancing is maintained using pi controller. this work is also extended to the abnormal and fault conditions. simulation results prove that under nonlinear unbalanced load conditions and abnormal fault conditions,upqc effectively compensates the voltage and current related power quality problems and thereby increasing power quality.