Unified Power Quality Conditioner Analysis Design and Control

The protection of sensitive loads from various current and voltage related problems can be achieved by using Unified Power Quality Conditioner (UPQC). In this paper, a control algorithm based on instantaneous symmetrical component theory (ISCT) is proposed for switching of Series Active Power Filter (SEAPF). The series voltage injected by the SEAPF effectively controls the load end voltage against various voltage related problems such as sag, swell and harmonics. The Shunt Active Power Filter (SHAPF) is controlled using power balance theory to compensate the reactive power demand, harmonic current and unbalanced loads. These SEAPF and SHAPF are controlled through derived reference load voltages and reference source currents respectively. These reference source currents are estimated using sensed load terminal voltage and DC bus voltage connected in between SEAPF and SHAPF. The proposed system is modeled in MATLAB environment and its performance is obtained under non-linear loads for harmonic compensations, voltage sag and swells. Experimental results are obtained on develop prototype to confirm findings of simulation results.