New generation of outdoor vacuum circuit breakers with rated voltage up to 40.5 kV

The paper describes design peculiarities of the novel compact vacuum circuit breaker with rated voltage 40.5kV. Design incorporates several novel technical solutions: polycarbonate support insulation, mono-stable magnetic actuator, labyrinth pulling insulator, core-type flexible contact and new compact vacuum interrupter (VI). For current and voltage sensing Rogowsky coil and capacitive dividers are applied. The module is encapsulated into silicon rubber providing required creepage distance and excellent tracking resistance. These novelties together with the extensive modeling of the mechanical and electrical fields followed by design optimization allowed reducing weight by more than 50% compared with alternatives available in the market.