A fuzzy-based control method for smoothing power fluctuations in substations along high-speed railways

The use of superconducting magnetic energy storage (SMES) for smoothing power fluctuations in a railway substation has been discussed. This paper proposes a smoothing control method based on fuzzy reasoning for reducing the SMES capacity at substations along high-speed railways. The proposed smoothing control method comprises three countermeasures for the reduction of the SMES capacity. The first countermeasure involves modification of rule 1 for smoothing out the average electric power to its average values. The other countermeasures involve the modification of the central value of the stored energy control in the SMES and revision of the membership function in rule 2 for the reduction of the SMES capacity. The SMES capacity in the proposed smoothing control method is reduced by 49.5% compared to that in the nonrevised control method. Computer simulations confirm that the proposed control method is suitable for smoothing out power fluctuations in substations along high-speed railways and for reducing the SMES capacity.