The research of coordination between voltage compensation superconducting fault current limiter and current relay

In this paper, based on structure and work theory of voltage compensation SFCL, the influences that voltage compensation SFCL brings to the current relay were studied in detail, and a solution was proposed. When taking place a fault in the power network, the short circuit current decreases because of the limiting impedance of SFCL, the current relay may be caused to malfunction because the line current may be less than its action current. Therefore, it is necessary to resetting the action current of the current relay to realize protecting whole line. As an example, 10KV isolated neutral distribution network system, the influences of current relay under three-phase short-circuit with SFCL and without SFCL were simulated respectively, and the results show the effectiveness of the solution.