Electric power line pilot protection decision method based on fault component positive sequence synthetic impedance

A fault component and comprehensive impedance technology, applied in the direction of automatic disconnection of emergency protection devices, circuit devices, emergency protection circuit devices, etc. Effect
CN101295874AInactive Publication Date: 2008-10-29DONGFANG ELECTRONICS
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Patent Information

Authority / Receiving Office
CN · China
Current Assignee / Owner
DONGFANG ELECTRONICS
Publication Date
2008-10-29
Estimated Expiration
Not applicable · inactive patent

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Abstract

The invention discloses a judgment method for the pilot protection of a transmission line based on the synthesized impedance of a positive-sequence fault component. Two protection devices are arranged at the two sides of a protected line segment; a communication channel is arranged between the two protection devices; the voltage phasor Delta U<m1> of the positive-sequence fault component and the current phasor Delta I<m1> of the positive-sequence fault component which are at the side are calculated, and the communication channel is utilized to obtain the voltage phasor Delta U<n1> of the positive-sequence fault component and the current phasor Delta i<n1> of the positive-sequence fault component which are at the same time and at the opposite side. The synthesized impedance of the positive-sequence fault component is calculated (refer to formula (1)), wherein, Delta U<cdl> is shown in formula (2). According to the size relation between the module value and the fixed value of the synthesized impedance of the positive-sequence fault component, whether the line segment has fault is distinguished so as to control the action of the protection devices.
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Description

technical field

[0001] The invention relates to a method for judging the longitudinal protection of power system lines in the field of relay protection of power systems, in particular to a method for judging the longitudinal protection of transmission lines based on fault component positive sequence comprehensive impedance, Background technique

[0002] Line current differential protection has been widely used in power systems. But affected by the capacitive current, the sensitivity of differential protection is low. At present, the method of reducing distributed capacitive current is generally to use compensation reactor or phasor compensation method, and some literatures have proposed some new longitudinal protection principles, such as the principle of line longitudinal protection based on the comprehensive impedance of the fault component. This principle does not require Compensate the capacitive current without being affected by the transition resistance. It can be use...

Claims

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