Enhancing Transient Voltage Quality in a Distribution Power System With SMES-Based DVR and SFCL

Conceptual design and performance evaluation of a voltage sag compensation scheme based on the superconducting fault current limiter (SFCL) and a MW-class dynamic voltage restorer (DVR) system integrated with superconducting magnetic energy storage (SMES) are presented and investigated. A pre-sag compensation strategy is introduced to lock the instantaneous magnitudes and phase angles of real-time line voltages for compensating the improper voltage components completely. A 0.3-H/1.76-kA SMES magnet is structurally designed for MW-class power exchange operations, and the SFCL's resistance is also estimated in detail. Various simulation cases with regard to voltage sag are carried out. The simulations have demonstrated that the proposed voltage sag compensation scheme is able to maintain the stabilizations of root-mean-square voltages, and mitigate the adverse effects of voltage sag on sensitive load. Furthermore, the compensated power injected to sensitive load by DVR is decreased owing to the additional voltage improvement provided by SFCL, thereby reducing the total capital costs of DVR.