The reliability of the gas-filled 110 – 750 kV circuit breaker units of substations

Statistical data on the operating reliability of 110 – 750 kV gas-filled circuit breaker units in the substations of the unified national electric power grid are analyzed. The structure of outages and planned downtimes of the elements of the units, namely, the circuit breaker and its actuator, the equipment of the unit (the current and voltage transformers, the disconnectors etc.), buses and secondary circuits, are presented. Proposals for increasing the reliability of distributors are substantiated.