A cost effective voltage sag compensator for distribution system

In a large power system voltage sag is considered to be the most common and critical power quality (PQ) issue. With the advent of power-semiconductor devices many PQ devices came into existence. Dynamic voltage restorer (DVR) and distribution static compensator (D-STATCOM) are normally employed as voltage sag mitigation devices. This paper presents a low cost alternative for voltage sag compensation. The proposed device does not require any energy storage device and has only one gate turn-off switch per phase for pulse width modulation, unlike DVR and D-STATCOM that employ DC-to-AC converter topology. Simulation analysis of three phase compensator is performed in MATLAB/Simulink environment and the total harmonic distortion of load voltage when the compensator is functioning during disturbance condition is within the acceptable limits. © 2015, The Society for Reliability Engineering, Quality and Operations Management (SREQOM), India and The Division of Operation and Maintenance, Lulea University of Technology, Sweden.