Method for reducing number of tripping times of circuit breaker by fault current limiting device

Abstract

The invention relates to a method for reducing the number of tripping times of a circuit breaker by a fault current limiting device, which aims to reduce the number of operation times of the circuit breaker and improve the power supply reliability and stability of an alternating current system. When the line has a fault, the fault current limiter is put into operation to reduce the fault current.But the fault current is still high compared with the current in normal operation, and a tripping command sent to the circuit breaker by a relay protection device is delayed after the line protectionis started. If the fault disappears in the delay time, the relay protection device does not send a tripping command to the circuit breaker after the delay; if the fault still exists, the relay protection device sends a tripping command to the circuit breaker to realize the fault isolation. According to the method, the circuit breaker does not switch off or switch on under the transient fault thatthe fault current borne by the power grid disappears in the continuous operation time, reduces the loss of the circuit breaker, also avoids the secondary impact on the system by reclosing and improvesthe operation stability of the system.

Description

technical field [0001] The invention belongs to the field of relay protection of electric power systems, and in particular relates to a method for reducing the number of tripping of a circuit breaker by using a fault current limiting device. A fault causes the circuit breaker to trip. Background technique [0002] In recent years, with the close interconnection of major power grids and the increase in power load, the scale of the power grid has continued to expand, resulting in an increase in the level of short-circuit current in the line. In order to limit the short-circuit current of the line, a common method is to install a current limiting device on the line. The current limiting device can limit the short-circuit capacity, reduce the impact of fault current on the dynamic and thermal stability of power grid equipment, improve the ability of the line to withstand the impact of fault current, and make the power grid continue to run longer in the event of a fault than wit...

AI Technical Summary

Problems solved by technology

[0003] The transmission and distribution lines of the power system are exposed to the external environment for a long time, and transient short-circuit faults caused by lightning, strong winds, birds and tree branches are prone to occur, which makes the circuit breaker open and close in a short time, reducing the use of circuit breakers life, reducing power supply reliability

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