Improvement of Voltage Profile using D-STATCOM – Simulation under sag and swell condition

Abstract: The study of shunt connected FACTS devices is a connected field with the problem of reactive power compensation and better mitigation of transmission related problems in today‟s world. In this paper we study the shunt operation of FACTS controller, the STATCOM, and how it helps in the better utilization of a network operating under abnormal conditions. Voltage sags and a swell in the medium and low voltage distribution grid impact on sensitive loads is severe. In this paper, the performance of voltage-source converter-based shunt 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. This research paper described DSTATCOM 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 DSTATCOM under voltage sags/swells conditions. The MATLAB simulation verification of the results derived has been obtained using a model of the three-phase DSTATCOM.

Keywords: Voltage Source Converter(VSC), Distributed Static Compensator (DSTATCOM), Flexible Alternating Current Transmission System, (FACTS), load voltage control, Transient, nonlinear load, swell condition.