Small-sized and high-reliability circuit breaker structure

Abstract

The invention discloses a small-sized and high-reliability circuit breaker structure. The structure comprises a rotating assembly (1), contact assemblies (2), a base assembly (3) and / or a built-in bridge connection piece, each contact assembly comprises at least one movable contact piece and at least one static contact piece, circuit planes which are arranged on the contact assembly at the same layer and penetrate through the corresponding static contact pieces and the rotating axis are parallel to the side surface of a shell, and wiring pieces connected with the static contact pieces are arranged at the two sides of each circuit plane respectively; when two or more layers of contact assemblies need to be in bridge connection, one contact piece of the built-in bridge connection piece is arranged at a static contact piece position at one layer, the other contact piece is arranged at a contact piece position at the adjacent layer, and therefore the two layers are connected in series in the product.

Description

technical field [0001] The invention relates to a circuit breaker structure with small size and high reliability, which belongs to electrical equipment. Background technique [0002] At present, the electrical circuit breaker based on the opening and closing of the brake contact and the static contact is very common, but when it is necessary to break the high-voltage direct current, because the direct current does not reach the zero point, the arc stretches longer when it is disconnected, and the switch is required to have a relatively Good arc extinguishing performance; especially in new energy photovoltaic applications, the internationally defined next-generation photovoltaic system DC voltage is 1.5KV, such a high voltage puts forward high requirements on the performance of the circuit breaker. Especially when the disconnect switch is built into the inverter, as the trend of inverter miniaturization is increasingly required by the market, the disconnect switch also needs ...

AI Technical Summary

Problems solved by technology

[0005] 1. Poor arc extinguishing ability

The arc extinguishing device cannot extinguish the arc in a short period of time, and even cannot extinguish the arc if the time is too long, resulting in burnt parts and short service life of the product

[0006] 2. Large heat loss

In some existing products, in order to limit the external size of the product and reduce the friction of the dynamic and static contact pieces, the dynamic and static contact pieces adopt a smaller contact area, and some products have adjacent contact layer contact pieces at the same position, so that multi-layer contact At the same time, the heating position of each layer is the same, so that the heat of the product is superimposed on each other; the large current heating loss is not conducive to improving the power conversion efficiency of application equipment (such as inverters)

[0007] 3. External bridges reduce reliability

When the product is applied to high voltage, it is mostly by increasing the number of contact layers, and then using external bridges to connect multiple layers in series. The external bridges are fixed by screws at the wiring position, which increases the risk of screw loosening during transportation and installation. , which reduces the stability of the product

Another disadvantage of the external bridge is that the wiring position of the bridge needs to be exposed outside the product, which reduces the creepage distance of the product, especially in the environment of electrical pollution or high humidity, which cannot meet the requirements of high voltage creepage distance

[0008] 4. The rotation locking structure is fixed on the plastic casing by screws, resulting in low reliability

This seriously reduces the stability and reliability of the product; in the high temperature and high humidity environment of some applications, the hardness of the plastic shell decreases. At this time, the fixing screws are easy to loosen when the force is applied. Work

This requires the selection of very high temperature resistant plastic shell materials to increase the bonding strength with the screws in extreme application environments, and the cost of the product will also increase

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