Stabilization of Power System Including Wind Farm by PWM Voltage Source Converter and Chopper Controlled SMES

Abstract

This paper presents a dynamic model of Superconducting Magnetic Energy Storage (SMES) device developed, which can significantly decrease the voltage and power fluctuations of grid connected fixed speed wind generators. The SMES system with a voltage–source IGBT converter and two–quadrant DC–DC chopper is analyzed as a controllable energy source. The objective of the proposed SMES control strategy is to smooth the wind farm output by absorbing or providing real power. Moreover, its reactive power output can also be controlled to keep the wind farm terminal voltage constant. The control methodology of SMES system is suitable for the two objectives stated above. The performance of the proposed system is evaluated by dynamic simulations using a test power system. Real wind speed data is used in the simulation analyses, which validates the effectiveness of the proposed control strategy. Simulation results clearly show that the proposed control strategy can smooth well the wind generator output power and also maintain the terminal voltage at rated level. Key words: Minimization of fluctuations; superconducting magnetic energy storage (SMES); wind generator stabilization; voltage source converter (VSC); DC–DC chopper