Improvement of Voltage output for Distribution System under Transient Condition with Dynamic Voltage Restorer

Abstract

Abstract-Voltage sags and swells in the medium and low voltage distribution grid are considered to be the most frequent type of power quality problems based on recent power quality studies. Their impact on sensitive loads is severe. In this paper, the performance of voltage-source converter-based series compensators used for load voltage control in electrical power distribution network has been analyzed and compared, when a nonlinear load is connected across the load bus. Possible control schemes and their effects on the oscillation attenuation are also studied. Such studied control schemes include the commonly used single voltage loop control, voltage feedback plus reference feed forward control, and double-loop control with an outer voltage loop and an inner current loop. This research paper described DVR principles and voltage restoration methods for balanced and/or unbalanced voltage sags and swells in a distribution system. Simulation results were presented to illustrate and understand the performances of DVR under voltage sags/swells conditions. The MATLAB simulation verification of the results derived has been obtained using a model of the three-phase DVR