Impact of fast-switching fault current limiter on the transient recovery voltage characteristics of circuit breakers in 750 kV power systems

Excessive short-circuit current critically limits power grid development. The Fast-Switching Fault Current Limiter (FSFCL), a novel type of Inductive Fault Current Limiter (IFCL), can significantly influence the Transient Recovery Voltage (TRV) characteristics across circuit breaker contacts during current interruption. This study refines the existing theoretical model of the TRV for circuit breakers by incorporating the impact of the oscillatory process in the contact voltage occurring between fault occurrence and circuit breaker interruption. The accuracy of the theoretical model was verified using a 750 kV system simulation model, while the impacts of the current-limiting inductance and parallel capacitance of both conventional IFCL and FSFCL on the TRV were investigated comparatively. The results reveal a non-monotonic relationship between the current-limiting inductance L f and both the TRV peak and Rate of Rise of Recovery Voltage (RRRV) in the FSFCL system, with multiple local minimum points appearing. Furthermore, the study shows that increasing the parallel capacitance C p reduces the RRRV. For the circuit breaker TRV with the FSFCL installed, in order to satisfy the requirements of the T100 envelope, three representative combinations of L f and C p can be selected as follows: L f = 40 mH with C p = 10 nF; L f = 62 mH with C p = 30 nF; and L f = 132 mH with C p = 20 nF.