Mitigation of Power Quality Problems with Reduced Switches Using Unified Power Quality Conditioner

This paper presents a control strategy for a three phase unified power quality (UPQC) for an improvement of different power quality problems. The UPQC is realized by integration of series and shunt compensation system. The shunt and series system is realized using a three phase, three leg voltage source inverter (VSI). A control technique based on unit vector tempulate technique (UTT) is used to get the reference signals for transmission line, while Icosφ algorithm is used for the control of shunt, series transsformer. The performance of the implemented control algorithm is evaluated in terms of voltage sag, swell and voltage dip in a three phase transmission system for different combination of linear and non linear loads. In this control method, the current voltage control is applied over the fundamental supply currents/voltage instead of fast changing current s voltages, thereby reducing the computational delay and the required sensors. MATLAB simulink based simulations results are obtained, which support the functionality of the UPQC.