High-power switch with current limiter

Abstract

The invention provides a high-power switch with a current limiter. The high-power switch comprises a main conducting loop and an arc extinction branch circuit. The main conducting loop is composed of hollow tubular main conductors, inner connecting bodies, outer connecting bodies, main static contacts, an annular dynamic main contact and the like. The arc extinction branch circuit is composed of an on-off device with the arc extinction function, the current limiter and the like. The arc extinction branch circuit is connected with the main conducting loop in parallel. The current limiter serves as a switch constitution element to be located in the main conductors. When the short circuit current is switched on / off through the switch, the main conducting loop is firstly switched off, the current is transferred to the arc extinction branch circuit, the short circuit current is limited within the on-off capacity of the on-off device through the current limiter, the short circuit current with a larger value can be accordingly switched on / off through the on-off device on the basis that the size is not increased and the design complexity is not improved, the design cost and the manufacturing cost of the switch are controlled within the more reasonable range, and the economic benefits of the product are increased.

Description

【Technical field】 [0001] The invention relates to the technical field of electrical switches, in particular to the design and manufacture of high-power switches. 【Background technique】 [0002] At present, high-power switches (such as generator circuit breakers) generally adopt the parallel design of the current-carrying circuit and the arc-extinguishing branch. The arc extinguishing chamber breaks the rated short-circuit current. When the peak value of the short-circuit current is very high, the strong current arc generated when the contacts in the arc extinguishing chamber are separated will burn the contacts. After the current crosses zero, the plasma between the contacts has a high concentration and temperature, causing the contacts to The thermal breakdown between them will cause the arc to re-ignite in the arc extinguishing chamber, resulting in failure to break the short-circuit current. If only by increasing the size of the arc extinguishing chamber or increasing t...

AI Technical Summary

Problems solved by technology

When the peak value of the short-circuit current is very high, the strong current arc generated when the contacts in the arc extinguishing chamber are separated will burn the contacts. After the current crosses zero, the plasma between the contacts has a high concentration and temperature, causing the contacts to The thermal breakdown between them will cause the arc to re-ignite in the arc extinguishing chamber, resulting in failure to break the short-circuit current

If only by increasing the size of the arc extinguishing chamber or increasing the volume of the arc blowing chamber to improve the breaking capacity of the arc extinguishing chamber, it will increase the weight of the entire switch, increase the cost, and increase the burden on the operating mechanism, etc.

At the same time, for this type of switch, re-development of a new interrupter with a larger breaking capacity will bring high technical risks and development costs, and require a long development time. If the demand is not large, it will bring High cost pressure, unable to achieve good technical and economic results

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