Automatic resetting method and system for station service power supply quick switching device

Abstract

The invention discloses an automatic resetting method and system for a station service power supply quick switching device. According to the method, when a power supply quick switching device is locked after receiving a protection locking external contact signal, if a switching starting instruction is continuously received and other conditions causing the device to be locked do not exist, the device automatically resets and quickly has a switching function; and if a grounding fault occurs in a station service power supply working branch, a relay protection system high-station transformer branch zero-sequence over-current protection first time limit action sends out a command for tripping the branch circuit breaker and locking station service power, along with tripping of the branch circuitbreaker, a protection device judges that a fault point is located in a high-voltage station service transformer branch, the branch zero-sequence over-current protection second time limit action continues to start standby power supply switching, the power supply rapid switching device achieves automatic resetting, auxiliary power supply switching is completed, and unit safety is guaranteed.

Description

technical field [0001] The invention belongs to the technical field of relay protection and safety automatic devices in power plants, and specifically relates to an automatic reset method and system for a plant power fast switching device, which is suitable for use between the plant system working power supply and the backup power supply in the power plant generator set accident state Quickly switch places. Background technique [0002] During the normal operation of the generator set in the power plant, the high-voltage plant transformer has its own plant power system to drive many plant auxiliary machines. In the event of an accident shutdown, in order to ensure the safe shutdown of the unit, the factory power needs to be switched to the backup power supply. This switching operation needs to be completed by the power supply fast switching device. That is to say, it is necessary to issue a switch command to start the plant power through the relay protection device, and the...

AI Technical Summary

Problems solved by technology

Therefore, even if the protection device operates correctly and trips the branch circuit breaker within the first time limit, and it is judged that the fault is between the branch circuit breaker and the high power substation, the fast switching device is immediately blocked and waits for manual reset, and the second time limit will be restarted after 200ms~500ms The switching of the backup power supply has no practical significance, and it will cause the loss of the power supply of the entire plant busbar, which will seriously affect the safety of the unit

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