Wind power smoothing scheme using SMES with reduced capacity

Due to random variations of wind speed, the output power and terminal voltage of a fixed-speed wind generator fluctuates continuously. In this paper, it is reported that the SMES system with a voltage-source IGBT converter and a DC chopper can smooth the line power and can also maintain the terminal voltage of fixed-speed wind generator at desired level, as it has both real and reactive power control abilities. For wind generator output power smoothing, constant output power reference is not a good choice, because sufficient power cannot be obtained when wind speed is very low, hence, more energy storage capacity is needed to smooth the wind farm (WF) output power. Therefore, among the various methods, a suitable method for selection of reference line power is presented. Finally, it is verified that the low pass filter (LPF) approach is very effective to smooth the line power with reduced energy storage capacity. It is also presented that SMES can improve the power quality of wind farm.