A fuzzy logic-controlled Superconducting Magnetic Energy Storage (SMES) unit for augmentation of transient stability

This paper presents a fuzzy logic switching of the thyristor controlled superconducting magnetic energy storage (SMES) unit to improve the transient stability of electric power system. In order to see how effective the proposed fuzzy logic-controlled SMES in improving the transient stability is, its performance is compared to that of a conventional PI (Proportional-Integral) controlled SMES scheme. Furthermore, a comparative study between the fuzzy controlled SMES method and fuzzy controlled braking resistor (BR) method is carried out. Simulation results of both balanced (3LG: Three-phase-to-ground) and unbalanced (1LG: Single-line-to ground) faults clearly indicate the effectiveness and validity of the proposed method in improving the transient stability. Moreover, the performance of fuzzy controlled SMES is found to be better than that of PI controlled SMES. Again, the performance of SMES is better than that of BR. Finally, it can be concluded that the proposed fuzzy controlled SMES strategy provides a very simple and effective means of transient stability enhancement of electric power system. © 2005 IEEE