Voltage Sag Compensation and Harmonic Reduction Using STATCOM based DVR with Phase Alternate Fuzzy Controller for Distribution Grid

Abstract

 The modern industrial equipments are more sensitive to Power Quality (PQ) problems and it is necessary to maintain better quality of electrical power. PQ   is affected due to the disturbances in distribution lines of the power system network. The voltage sag is a major concern in the distribution system due to the disturbance at remote bus. The harmonic currents are generated by non-linear loads present in the system. Superconducting Magnetic Energy Storage (SMES) coil based Dynamic Voltage Restorer (DVR) with phase alternate fuzzy controller is proposed to improve the PQ. The proposed controller uses least active power which is stored in the SMES system for voltage sag compensation. It reduces Total Harmonic Distortion (THD) and sag compensation time during extreme variation in the phase. The proposed controller is based on phase adjustment as pre-sag compensation to restore amplitude and phase angle of the sensitive load voltage. Further it uses the phase change approach based on direct quadratic (d-q) synchronous reference frame to determine DVR reference voltage. This paper analyses the operation principle of the SMES based DVR, and designs the DVR with phase alternate fuzzy control method using MATLAB SIMULINK, the models of the SMES based DVR with phase alternate fuzzy controller  is established, and the simulation tests are performed to evaluate the system performance.