Optimal operation of Unified Power Quality Conditioner (UPQC) in order to simultaneous voltage unbalance and load reactive power compensation

This paper introduces a methodology for optimal utilization of unified power quality conditioner (UPQC). In this method, series active power filter (Se APF) of UPQC is controlled by using instantaneous power theory (also named p-q theory) and power angle control method (PAC) to compensate unbalanced voltage (asymmetrical voltage sag/swell with phase-angle jumps) and load reactive power sharing with the shunt active power filter (Sh APF) simultaneously. Since voltage variations like voltage sag/swell is a short duration power quality problem in distribution systems, therefore under normal operating conditions, the series inverter is not utilized effectively. By using the proposed method, optimal utilization of series inverter and also reduction in the shunt inverter rating, will be achieved. A mathematical based analysis for the approach is presented and results are verified using Matlab/Simulink.