Improved Testing Method Using the Multi-Transformers Synthetic Circuit to Verify Capacitive Charging Current Switching Capability of High-Voltage Circuit Breakers

Abstract

To perform a capacitive current switching test (CCT) at AC extra-high-voltage (EHV) and above level, this paper proposes a new multi-transformer synthetic circuit (MTSC) test method that replaces the general synthetic test method using capacitor banks. An MTSC method has a simpler circuit structure compared to other synthetic testing methods and has higher equivalence (especially recovery voltage and TRV) and validity. Using this method, CCTs for circuit breakers (CBs) of the AC 420 kV voltage class were performed as a field test using the IEC 62271-100 standard. To verify that the test method was valid, test results were analyzed and compared with the requirements of a standard. Consequently, the MTSC method completely covered the requirements of the standard.

Keywords

• capacitive current switching test
• multi-transformer
• synthetic test
• high-voltage circuit breaker