Rapid fault current limiter

Abstract

The invention provides a rapid fault current limiter. The current limiter comprises a current limiting reactor, a super-speed mechanical switch, a switch control system, a capacitor, a lightning arrester, a current transformer and an insulation cabinet. A main controller controls the super-speed mechanical switch to be turned off and turned on. When the circuit current is in stable state, the super-speed mechanical switch is turned off, and the current limiting device shows low impedance externally. The circuit suffers from short-circuit fault or overcurrent, the switch control system detectsthat the circuit current exceeds the threshold value, the super-speed mechanical switch is turned off in a high speed and the fault current limiter shows high impedance externally, thereby achieving the function of effectively inhibiting the short-circuited current. When the first big half-wave of the current passes the zero point, the circuit recovers to operate normally.

Description

technical field [0001] The invention relates to the field of high-voltage electrical switchgear, in particular to a fast fault current limiter. The current limiter is suitable for automatic and rapid current limiting processing when a short circuit fault or overcurrent occurs in the power system and traction power supply system. Background technique [0002] With the rapid development of the national economy, the high-voltage and large-capacity power supply system has been further developed, and the short-circuit current level of the system is also increasing. When a power failure occurs at the outlet of the power system substation or traction substation, the maximum short-circuit current can reach more than 100kA , while the breaking current of the more commonly used vacuum circuit breakers in China is below 63kA, which has far exceeded the breaking capacity of the circuit breaker, and there is a great potential safety hazard. If the short-circuit current is not limited in...

AI Technical Summary

Problems solved by technology

Due to its high cost and immature technology, superconducting current limiters are not suitable for large-scale application at present; solid-state current limiters and series resonant current limiters are the main hot spots of current development, but solid-state current limiters are The solid-state switch has poor voltage resistance and high on-state loss. The series resonant fault current limiter has high cost and operation and maintenance problems of the control system, and the mechanical switch type fault current limiter also has a short switching time. long wait question

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