Investigation on the characteristics of a high speed repulsion mechanism for wide-range operation of resistive type SFCL

The fault current in a large-scale power system is higher and difficult for conventional breakers to interrupt it. Resistive type high temperature superconducting fault current limiter (HTSFCL) can reduce fault current and achieve a fast operation which makes it a good supplement for conventional breakers. High speed repulsion mechanism driven by the short circuit current through the parallel reactor was used to drive the vacuum interrupter to cut off the current of superconductor side in 10~15ms to prevent it from destroy. According to this, we did some simulation about the key parameters which may influence its electromagnetic force, velocity and movement. Also, as the short circuit current was different, the velocity and movement of the repulsion mechanism varied a lot. Thus, proper parameters for the design of repulsion mechanism are very necessary for wide-range operation. According to this, we did some experiments to investigate the key parameters and came out with a prototype and succeeded. At last, interrupting test with recovery voltage was done to ensure its wide-range operation ability.