Voltage Dip/Swell Mitigation and Imaginary Power Compensation in Low Voltage Distribution Utilizing Improved Unified Power Quality Conditioner (I-UPQC)

The main purpose of this work is to introduced power quality improvement in low voltage distribution networks with the application of Improved Unified Power Quality Conditioner (I-UPQC). Ordinarily, in the normal UPQC, the series inverter handles active injection while the shunt inverter provides load imaginary power injection. However, in the case of I-UPQC, the series inverter of the UPQC performs two functions concurrently as a sag and swell compensator and assists the shunt inverter in load reactive power requirements. The reactive power sharing is achieved by the integration of the Power Angle Control (PAC) of UPQC to coordinate imaginary power-sharing between the two inverters. With the view that the series inverter produces active and reactive power, this concept is named I-UPQC. Full mathematical analysis to extend the PAC method to I-UPQC has been carried out in this work. The simulation and results produced in the MATLAB / SIMULINK environment and discussion to support the developed concept are also presented. The result from the proposed concept is confirmed by comparing the concept with operation unified power quality conditioner in steady-state.