Device and method for cutting off short-circuit current

Abstract

The invention discloses a device and a method for cutting off short-circuit current. The device can improve the arc extinguishing performance of a circuit breaker, improve the cut-off capacity of the circuit breaker and shorten the arc extinguishing time of the circuit breaker. The device comprises the circuit breaker, a high-voltage switch and a magnetic saturation reactor. The high-voltage switch is connected in parallel with the magnetic saturation reactor and then connected in series with the circuit breaker. The device for cutting off the short-circuit current is connected in series with a power supply loop. When a power system runs normally, the high-voltage switch of the device for cutting off the short-circuit current is closed, and the circuit breaker is also closed. When the power system runs normally, the device for cutting off the short-circuit current has zero loss. When the power system is short-circuited and the short-circuit current needs to be cut off, the high-voltage switch of the device is first tripped, and the magnetic saturation reactor is connected into a short-circuit current loop. The magnetic saturation reactor reduces the current values of the short-circuit current in sections surrounding a zero crossing point and prolongs the time of the current in low-current sections surrounding the zero crossing point. Then the circuit breaker is tripped to cut off the short-circuit current.

Description

[0001] technical field [0002] The invention relates to the field of power transmission and transformation in power systems, in particular to a device and method for cutting off short-circuit current. Background technique [0003] With the continuous development of the power system and the continuous increase of power generation capacity, the short-circuit current caused by the short-circuit of the power system increases accordingly. The increase of the short-circuit current has great harm to the stability of the power system and the safety of the equipment. The ability of the circuit breaker to cut off the short-circuit current is limited. When the short-circuit current exceeds the maximum cut-off current value of the circuit breaker, the circuit breaker cannot cut off the short-circuit current. The development of high-voltage and large-capacity circuit breakers has become a difficult subject in the field of switching appliances. [0004] The short-circuit current limite...

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Problems solved by technology

However, the manufacturing cost of the method proposed by this patent is still relatively high

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