Stabilization of wind farm by PWM voltage source converter and chopper controlled SMES

This paper proposes a control methodology for Superconducting Magnetic Energy Storage (SMES) unit, 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 using IGBT is proposed as a controllable energy storage device. The objective of the proposed SMES control strategy is to smooth the wind farm output power and terminal voltage by absorbing or providing both real and reactive powers. Thus the control methodology of SMES system is suitable for two objectives stated above. The performances of the proposed system are evaluated by dynamic simulations using a test power system. Real wind speed data are used in the simulation analyses, which validate 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.