Transient Recovery Voltage Characteristics of Fast Switch in 500 kV Systems Equipped with Fast-switching Fault Current Limiter

As a prominent countermeasure to address the issue of exceeding short-circuit current levels in power systems, the Fast-Switching Fault Current Limiter (FSFCL) is highly susceptible to reignition during its fast interruption process due to the Transient Recovery Voltage (TRV) generated. Based on an in-depth derivation of the TRV mechanism of the fast switch, this paper establishes a 500 kV system simulation model equipped with FSFCL and analyzes the impact of fault inception time on the fast switch TRV. The effects of the parallel capacitor, current-limiting reactor, and fault distance on the fast switch TRV were investigated. The results indicate that under terminal faults, the fast switch TRV is the most severe when a short-circuit fault occurs at the peak of the bus voltage. Selecting reactor with a large inductance can increase the Rate of Rise of Recovery Voltage (RRRV) across the fast switch, whereas increasing the capacitance can serve as a measure to suppress the RRRV. As the fault distance increases, the time required for the TRV to reach its first peak gradually increases. Both the peak of TRV and the RRRV across the fast switch decrease gradually as the fault distance increases.