Simulation on the high current interruption principle for hybrid circuit breaker of vacuum interrupter and CO2 gas interrupter

CO2 gas is a possible substitute for SF6 gas in circuit breaker with relatively superior arc interruption performance. To enhance the interruption capacity of the circuit breaker which employs CO2 gas as its arc interruption dielectric, the interruption principle of the hybrid circuit breaker composed of vacuum interrupter and CO2 gas interrupter is studied. Based on the black-box arc models of hybrid circuit breaker built in ATP-EMTP, the interactions characteristics of vacuum interrupter and CO2 gas interrupter and the transient recovery voltage distribution between two interrupters during the interruption process are analyzed. The influence of voltage-dividing capacitors on transient recovery voltage distribution is discussed. The interruption capacity of hybrid circuit breaker and CO2 gas circuit breaker are compared. The results of simulation demonstrate that preferable transient recovery voltage distribution can be obtained under suitable control strategy while interrupters paralleled with voltage-dividing capacitors. The vacuum interrupter series connected with CO2 gas interrupter can assist in enhancing the high current interruption capacity of gas interrupter.