Fuzzy Logic Based UPQC by Addition of a Superconducting Magnetic Energy Storage System

Abstract

Modern power grids must be highly reliable and provide power with a high quality. Power quality issues like voltage sags or current harmonics must be minimized, in order to achieve high levels of reliability in the system. One possible way to overcome such problems is through the utilization of active power filters like a Unified Power Quality Conditioner (UPQC).As the demand of electricity is increasing day by day, it is necessary to supply a good quality of power to customers. In the future, distribution system operators could decide to supply their customers with different PQ levels and at different prices. Due to the presence of nonlinear loads in the system many problems like fluctuations, flickers, voltage sag, voltage swell etc. comes in the system.Series compensator which is meant for voltage restoring is controlled by a fuzzy logic controller. Shunt compensator’s operation is controlled by extracting d and q axis current from load current and DC link voltage is maintained through a fuzzy logic controller. The performance of UPQC mainly depends upon how quickly and accurately compensation signals are derived. Thus, the combination of weak grids, wind power fluctuation and system load changes produce disturbances in the PCCvoltage, worsening the Power Quality is stability. In this paper, a fuzzy logic controller with reference signal generation method is designed for UPQC. This is used to compensate current and voltage quality problems of sensitive loads. The results are analyzed and presented using Matlab/Simulink software.