Relay protection method based on the principle of amplitude comparison

Abstract

The invention relates to an amplitude comparison principle-based relay protection method. A protection apparatus carries out sampling filtering on a current waveform of a mutual inductor by utilizing a feature that current amplitudes are equal in an external short circuit state; currents at two sides of protected equipment are obtained by using a communication way; and on the basis of comparison of the two-side current amplitudes, the amplitude comparison principle-based relay protection method is formed. According to the relay protection method, enough security is provided for an external fault and enough sensitivity is provided for an internal fault; and the requirement for consistency of fiber channel route is loosened. The influence of the system equivalent impedance angle difference at the two sides of the fault point can be eliminated. And when a fault occurs at power angle spreading at the two sides of the system during oscillation, the amplitude comparison principle-based relay protection method can realize the good performance. Therefore, the provided amplitude comparison principle-based relay protection method has the wide application space and can be widely applied to transmission line protection, generator protection, transformer protection, and bus protection and the like.

Description

Technical field

[0001] The invention belongs to the field of electric power systems, and more specifically relates to a method of relay protection. Background technique

[0002] In ultra-high voltage transmission lines, optical fiber differential protection has been widely used as the main protection.

[0003] The principle of optical fiber differential protection is advanced, but the transmission and reception routes of the optical fiber channel are required to be consistent. The typical criterion of differential protection is based on the proportional braking differential between "phasor sum" and "phasor difference". If the transmission line has a fault in the area, if the system equivalent impedance angle difference on both sides of the fault point is large, or when the transmission system is oscillating, when the power angle of the system on both sides of the oscillation fails, the sensitivity of the traditional differential protection will be generated. To a certain extent, ...

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