68 / 2024-04-09 08:27:03

Research on Breaking Conditioning Method of Vacuum Interrupter Based on Multiple Re-strikes

vacuum interrupter; dynamic breaking; multiple re-strike; breaking conditioning; dielectric recovery strength

The breaking conditioning of vacuum circuit breakers significantly improves the withstand voltage level and rapid insulation recovery of the vacuum interrupter chamber, which is crucial for successfully switching capacitor banks in 12kV vacuum interrupter. This paper introduces a dynamic breaking conditioning test method for vacuum interrupter chambers based on the competitive relationship between the rate of recovery voltage rise applied across the contacts of the vacuum circuit breaker and the rate of recovery of the arc gap insulation. By inducing multiple consecutive re-strikes on the contact surface during the breaking process, weak points on the contact surface are eliminated, leading to a gradual increase in dielectric recovery strength. A dynamic breaking conditioning test platform for vacuum interrupter chambers was constructed, featuring an average contact separation speed of 0.89m/s, a rise time of 0.5ms for the recovery voltage at the contact separation point, and a breaking voltage of 40kV. Dynamic breaking tests were conducted on different specifications of CuCr contacts in a simulated vacuum interrupter chamber with detachable contacts. The test results show that the resistance to re-strikes of vacuum interrupters has improved - the number of breakdowns has decreased, the withstand voltage level has significantly increased, and adverse factors on the contact surface have been eliminated. Additionally, The test process also assessed the dielectric recovery strength of the vacuum interrupter chamber at different times and states without causing damage to the electrodes.