Breaker

Abstract

The present invention provides a DC breaker. According to the breaker, connection directions at a leakage power source side and a load side are not limited. The breaker comprises a foundation (11), a static contact (27), a moving contact (23), an arc extinguishing device (50) and a pair of permanent magnets (54a, 54b), wherein the static contact is arranged on the foundation and has a static contact point (21), the moving contact has a moving contact point (22), the moving contact point (22) can contact with and separate from the static contact point, the arc extinguishing device (50) comprises multiple grid pieces (51), the grid portions have cutting portions (51a) and side foot portions (51b) which are formed close to one side of the moving contact, the cutting portions (51a) are U-shaped structures, the side foot portions (51b) are arranged at two sides of the cutting portions, the two contact points are surrounded, the static contact is configured at an inner side of the cutting portions (51a), the pair of permanent magnets are configured at two sides of the static contact point and are configured in a mode that same poles are opposite to each other.

Description

technical field [0001] The present invention relates to a circuit breaker (Circuit Breaker) which uses a permanent magnet to increase the driving force (ark driving force) for an arc. Background technique [0002] Since direct current does not have a zero potential, the direct current is interrupted, for example, by driving the arc with a pressure gradient (pressure difference) generated when the arc touches an insulating material arranged near the contacts, and the arc is guided to the grid. (grid) piece and is cut off, thereby cutting off the DC current. In addition, when the voltage is high, the arc voltage can be increased by increasing the number of grids, or the magnetic power (driving force provided by the magnetic field) can be increased by reducing the reluctance on the grid side. However, the necessary condition for using these methods is that the current to be cut off is relatively large (for example, above 100A), enough to allow the arc to reach the grid, and fo...

AI Technical Summary

Problems solved by technology

Therefore, in a circuit breaker that defines the connection direction between the power supply side and the load side, that is, in a circuit breaker that arranges permanent magnets with opposite poles near both sides of the two contacts, due to the flow direction of the return current Opposite to the predetermined current flow direction, so the arc is driven in the opposite direction to the arc chute, which may result in failure to cut off the current

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