Research on the Influence of 500 kV Fault Current Limiter on Line Distance Protection

Fault current limiters(FCLs) are effective measures to limit short-circuit current(SCC). However, traditional FCLs have a relatively long operating time. This article proposes an economical fault current limiting device with a large capacity and fast switch in parallel with a high impedance current limiting reactor. It takes 6 to 20 ms from fault occurrence to reactor operation, and the duration is far less than 60 to 100 ms needed for general relaying and circuit breaker on-off at least; At the same time, the operational features of the new FCL were analyzed, and the mechanism of the change in line parameters caused by the connection of the FCL, which in turn affects distance protection, was studied. Finally, a simulation analysis was conducted on a real power grid to demonstrate the validity of the proposed measure.