Capacitor Energy Storage Synthetic Testing of H.V.D.C. Circuit Breakers

A capacitor energy storage circuit was designed and constructed to perform synthetic tests on H.V.D.C. breakers. The circuit was used to evaluate a module of a 500 kV 2.2 kA SF6 H.C.D.C. circuit breaker and a Metallic Return Transfer Breaker (MRTB) for the 400 kV, 2.2 kA d.c. inter-tie circuit of Bonneville Power Administration (BPA). An analysis of the circuit is presented and the operation of the circuit is discussed. Guidelines for selecting components and setup of the circuit are presented. Test results at 2.2 kA for a H.V.D.C. SF6 breaker with a recovery voltage of 170 kV and for a MRTB with a recovery voltage of 80 kV using this circuit are given. The MRTB results are compared with actual field tests showing that this synthetic circuit produced valid results. Synthetic circuits are extremely useful for development type tests on H.V.D.C. circuit breaker because of the simplicity and flexibility of the circuit.