A detection method for phase failure of starting standby transformer based on optical ct

Abstract

The invention discloses an optical CT-based detection method for phase failure of a starting backup transformer. The start-up backup transformer of the power plant is used as a backup power source and is under no-load conditions for a long time; once a single-phase failure occurs, the voltage phasor and voltage sequence components on each side do not change significantly; A major threat to the safe operation of the plant. The present invention uses optical CT to detect the three-phase current at the high-voltage side of the starting backup transformer. When the current meets the phase failure criterion, it is determined that a phase failure has occurred. After a delay, an alarm signal is given and the operator is notified to deal with it in time, which improves the power generation. The operational reliability of the factory start-up backup transformer system.

Description

technical field [0001] The invention relates to the field of protection and monitoring of a start-up backup transformer system in a power plant, and more particularly relates to a detection method for a phase failure of a start-up backup transformer system in a power plant. Background technique [0002] In the power system, non-full-phase operation due to various reasons will cause the generator to overheat or burn out, resulting in abnormalities in the power system of the power plant, which is not only a major loss to the power plant, but also affects the safe operation of the power system. Therefore, how to prevent non-full-phase operation accidents in the power system must arouse our attention. [0003] The World Association of Nuclear Operators (WANO) highlighted several phase failures of nuclear power plants and the resulting serious consequences in their experience feedback (SOER 2015-1 Safety Challenges from Open Phase Events) in 2015, hoping to attract the attention ...

AI Technical Summary

Problems solved by technology

However, this method cannot point out the phase difference of the open-phase fault; and there is a certain overlap with the characteristics of the single-phase ground fault of the standby transformer (at this time, the ground current will also flow on the primary side Y connection line), and the identification of the open-phase fault is not unique. ; The Rogowski coil it uses has no relevant description on the measurement range and effect of the ground zero-sequence current

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