Application of flexible control methods for D-STATCOM in mitigating voltage sags and swells

This paper proposes three control methods for D-STATCOM (Distribution Static Compensator) control system. The operation of these control methods enables D-STATCOM to mitigate every type of voltage distortions, intelligently (caused by load variations and three-phase fault). This paper validates the performance of a D-STATCOM system in improving distribution system performance under all types of system related disturbances. The proposed system is simulated in PSCAD/EMTDC software. Simulations for the first and second methods are implemented and the results of simulations for these two methods are compared. Finally, the third method is proposed as a “Hybrid Solution”. The third method comprises all advantages of two mentioned methods and mitigates all their disadvantages. The reliability and robustness of the control schemes in the system response to the voltage disturbances caused by load variations and three-phase faults are obviously proved in the simulation results.