PRACTICES OF DESIGNING 110 KV DEAD TANK TYPE VACUUM CIRCUIT BREAKERS

The up-to-date state of high-voltage dead tank type vacuum circuit breakers, distinctive features of dead tank circuit breakers are considered; a range of issues arising at the design of high-voltage dead tank type vacuum circuit breakers with voltage of 110 kV is presented. The possible ways of improving electric strength of a dead tank circuit breaker with vacuum arc-quenching chamber by means of electric-field distribution optimization inside the chamber considering its placement in the earthed tank are showed. The results of preliminary calculation and experimental research of electric strength of the gas gaps of prototype dead tank type vacuum circuit breaker pole are provided. The influence of the tank diameter on electric strength of the dead tank circuit breaker is indicated. The prototype thermal performance evaluation based on the benchmark study at vertical and horizontal positions of circuit breaker pole tank is reported. Thermal performance of the prototype dead tank type vacuum circuit breaker pole under continuous current of 3150 А is presented. The application features of spring drive in dead tank type vacuum circuit breakers are examined. The data of kinematic chain elements of a circuit breaker with spring drive, calculation estimates and experimental results of mechanical behaviour of prototype dead tank type vacuum circuit breaker pole with spring drive are provided.