The Research Of Coordination Between Voltage Compensation Superconducting Fault Current Limiter And Relay

With the development of power system, the short-circuit current level of powergrid is constantly growing. In order to improve the situation, installing thesuperconducting fault current limiter (SFCL) in power grid has been the most idealmeasure. But the normal work of relay devices in power system will be affected bythe shifty impedance characteristics of SFCL. In terms of practical application, thecoordination between SFCL and relay is one of the key issues. Therefore, thecoordination problem is studied in this thesis.Firstly, the structure and work theory of voltage compensation SFCL aredescribed. Based on the current limiting mode and pulse width modulation (PWM)current control method, the simulation model of this SFCL is build. The currentlimiting performance is analysed through simulation. The influences of SFCL onpower system and power equipment are deeply researched with the transientstability, automatic reclosing device and relay. This thesis proposes a solution tosolve the coordination between voltage compensation SFCL and the current relay,distance relay and zero-sequence relay.In this thesis, 10KV and 110KV systems as examples, the influences of relayunder short-circuit fault with SFCL and without SFCL were simulated respectively.The simulation shows that the reach of protection slightly downsized throughresetting relay, but the coordination between relay is not affected. And whenshort-circuit fault appears in any place of power system, the relay can cut-off thefault in 0.5s. It realizes the coordination between voltage compensation SFCL andrelay, the results show the effectiveness of the solution.