Double-break vacuum circuit breaker used for 66 KV

Abstract

The invention provides a double-break vacuum circuit breaker used for 66 KV. The vacuum circuit breaker comprises two break devices with the same structure, each break device is arranged in a vacuum arc-extinguishing chamber, the break device comprises a static contact and a moving contact, a vacuum gap is reserved between the static contact and the moving contact, tail portions of the moving contacts at two sides are connected in series through a connecting rod, the connecting rod is provided with a bidirectional repulsive force mechanism and a permanent magnet maintenance mechanism in sequence, the bidirectional repulsive force mechanism comprises a metal repulsive force disc, the connecting rod is also provided with an upper fixing plate and a lower fixing plate parallel to the metal repulsive force disc, the metal repulsive force disc is located between the upper fixing plate and the lower fixing plate, the lower end surface of the upper fixing plate is fixedly connected with a switch-off coil, and the upper end surface of the lower fixing plate is provided with a switch-on coil. The beneficial effects of the vacuum circuit breaker are that the on-off 66 KV voltage level is realized through double breaks, the double breaks are linked by employing an electromagnetic repulsive force, a mechanical locking structure is avoided, fault sources are less, the usage reliability is high, the operation precision and the synchronism of the break devices are high, and the reaction can reach a microsecond level.

Description

technical field [0001] The invention belongs to the field of vacuum circuit breakers, in particular to a double-break vacuum circuit breaker for 66KV. Background technique [0002] In the 66kV voltage level, sulfur hexafluoride (SF 6 ) circuit breakers account for the vast majority of this voltage level, while SF 6 As a greenhouse gas, its impact exceeds that of CO 2 It is 25,000 times higher than that, causing great harm to the environment, while vacuum circuit breakers will not affect the greenhouse effect, which belongs to the direction of sustainable development, but it is difficult for a single-break vacuum circuit breaker to achieve a voltage level of 66KV; [0003] In vacuum circuit breakers, the breakdown voltage of the vacuum gap has a clear relationship with the gap. Experiments show that: when the gap distance is less than 0.5cm, the breakdown voltage U increases linearly with the increase of the gap distance; When the gap distance is large, the relationship be...

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Problems solved by technology

That is to say, there is a saturation effect between the breakdown voltage and the gap length. Under the long vacuum gap, the withstand voltage level of the vacuum circuit breaker cannot be obtained by simply increasing the length of the vacuum gap. Therefore, at the 66kV voltage level, the single-break vacuum circuit breaker The device cannot meet the requirements

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