Full-current differential protection braking coefficient adaptive regulating method for transmission line

Abstract

The invention provides a full-current differential protection braking coefficient adaptive regulating method for a transmission line. The method comprises the following steps of: acquiring the current on the two sides of a line; and adaptively regulating a braking coefficient of full-current differential protection according to the intensity of a load current and whether the line is a weak feed line in four situations. By the method, the braking coefficient of the full-current differential protection is adjusted in real time according to the load of the line, so that the sensitivity of the full-current differential protection and the adaptability of protection criterion can be improved, and the action performance of a relay protection device can be improved.

Description

technical field [0001] The invention belongs to the field of relay protection of electric power systems, and in particular relates to an adaptive setting method of braking coefficient of full current differential protection. Background technique [0002] The full current differential protection criterion of the transmission line is composed of the action amount and the braking amount, and the action amount is the modulus of the sum of the current phasors on both sides of the line The braking amount is the modulus of the current phasor difference on both sides of the road The product of braking coefficient K when When, the differential protection action, when , the differential protection does not operate. The braking coefficient generally adopts a fixed value, which is set by the manufacturer inside the device. [0003] The load current of the line will affect the operating performance of the full current differential protection. When the line is grounded through h...

AI Technical Summary

Problems solved by technology

[0003] The load current of the line will affect the operating performance of the full current differential protection. When the line is grounded through high resistance, the fault current component is small, and the load current is greater than the fault current component. If the brake coefficient is not selected properly, it may cause a fault in the zone, and the full current differential protection will refuse to operate.

[0004] To sum up, for the changing load current, the full current differential protection adopts a fixed braking coefficient, which has poor adaptability. For faults in the heavy load area, the sensitivity of the full current differential protection will decrease.

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