Low current electric arc magnetic blow-out device and arc-blowing method of medium-pressure direct current breaker

Abstract

The invention discloses a low current electric arc magnetic blow-out device and an arc-blowing method of a medium-pressure direct current breaker. According to the device, a V-shaped arc extinguish chamber grid sheet is adopted, a magnet exciting coil is arranged on the side surface of an arc extinguish chamber shell, which is parallel to the grid sheet, the magnet exciting coil is externally connected with a low current detecting and judging system, and a piece of Y-shaped magnetism enhancing armature iron is arranged at each of the two sides of the arc extinguish chamber shell, which correspond to the regions of movable and fixed contacts and an arc running channel. According to the magnetic blow-out device, the magnetic fields of the regions of the contacts and the arc running channel are effectively enhanced, thereby playing obvious effects on the facts that lower current electric arcs in the contact region can fast enter the grid sheet, the electric arcs can be broken successfully, and the fault probability of the device can be reduced. In addition, the device is compact in structure, can reasonably utilize optimizable breaker spatial layout and results in the reduction of the volume.

Description

technical field [0001] The invention designs a quick tripping device applied to a DC circuit breaker, and in particular relates to a small current arc magnetic blowing device and an arc blowing method for a medium-voltage DC circuit breaker. Background technique [0002] With the continuous advancement of the modernization process, the DC power supply system has become more and more closely related to industrial development and people's daily life. At present, many important industries such as urban rail transit, solar power generation, smelting, chemical industry, ship power, and mining have adopted DC power supply systems. power supply system. Among them, the DC circuit breaker has the protection function of reliably cutting off the fault current of the DC circuit, which is the guarantee for the safe operation of the DC power supply system. With the rapid development of our country's economy and the gradual modernization of the industrial and transportation sectors, the r...

AI Technical Summary

Problems solved by technology

In addition, when the breaking current value is large, the magnetic field intensity of the contact and the arc running area is relatively large, and the effect of the magnetic blowing arc is obvious, so the large current arc is easier to break

However, when breaking the small current arc, the magnetic blowing effect is obviously weakened, and the electromotive force of the transverse magnetic field received by the small current arc is too small, so that the arc cannot quickly enter the grid for cooling and cutting, but stays between the contacts for a long time Burning, resulting in severe ablation of the moving and static contacts, material loss, and local concentration of metal droplets on the surface of the contacts splashing, eventually leading to breaking failure

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