A line longitudinal differential protection method based on current zero-crossing for synchronization

A longitudinal differential protection and zero-crossing technology, applied in emergency protection circuit devices, electrical components, etc., can solve the problems of high channel performance requirements, complex technology, high communication speed requirements, etc., and meet the communication speed and channel performance requirements. Low, less dependent, economical effect
CN113270856BActive Publication Date: 2022-07-26STATE GRID HENAN ELECTRIC POWER ELECTRIC POWER SCI RES INST +5
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Patents(China)
Current Assignee / Owner
STATE GRID HENAN ELECTRIC POWER ELECTRIC POWER SCI RES INST
Publication Date
2022-07-26

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Abstract

The present application discloses a line longitudinal differential protection method based on current zero-crossing point for synchronization, including: detecting and classifying the zero-crossing point of the current before the fault; after the protection starting element acts, selecting a zero-crossing point as a reference point, and virtualizing a zero-crossing point The sine wave is used as the reference phasor; the amplitude and phase of the current phasor are calculated with the virtual reference phasor as the reference; the time difference between the current sampling time and the reference point is used as the time label; the amplitude, phase and time of the current phasor are included The current information of the current side of the label and the zero-crossing point type is sent to the opposite side; the current information of the current side and the opposite side is compared, and the current information of the opposite side is processed; the current information of the current side and the opposite side with the same time tag is used to calculate the differential current and Braking current to achieve synchronization of current on both sides. The present invention is not affected by the inconsistency of the delay of the receiving and sending channels, has low requirements on the communication rate and channel performance, is not strongly dependent on the longitudinal channel, and has the advantages of strong economy and high reliability.
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Description

technical field

[0001] The invention belongs to the technical field of power system relay protection, and relates to a line longitudinal differential protection method for synchronization based on current zero-crossing point. Background technique

[0002] The longitudinal current differential protection has the advantages of stable protection range, high sensitivity, fast action speed, and little influence by the change of system operation mode. It has been widely used in high-voltage transmission lines. However, the correct action of the pilot current differential protection is premised on the precise synchronization of the current on the current side and the opposite side.

[0003] The traditional differential protection synchronization method is based on the data channel for synchronization, which requires consistent delay of the receiving and transmitting channels, high channel performance requirements, complex technology and high cost, which limits the application of lo...

Claims

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