Method of realizing line-to-ground fault phase selection by using sequence voltage phase characteristic

A technology of phase characteristics and line grounding, applied in emergency protection circuit devices, electrical components, etc., can solve the problem of insufficient phase selection sensitivity of phase voltage sudden change, insufficient sensitivity of three-phase short-circuit fault, and cannot be applied to high-resistance grounding short-circuit fault selection of transmission lines. Equal problem, to achieve the effect of high phase selection sensitivity

CN103368151AInactive Publication Date: 2013-10-23STATE GRID CORP OF CHINA +2
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Patent Information

Authority / Receiving Office
CN · China
Current Assignee / Owner
Publication Date
2013-10-23
Estimated Expiration
Not applicable · inactive patent

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Abstract

The invention discloses a method of realizing line-to-ground fault phase selection by using a sequence voltage phase characteristic. The method comprises the steps of firstly using the phase relation between zero-sequence voltage and A phase negative sequence voltage to form a criterion and accurately judging whether a transmission line fault is a grounded short circuit fault; secondarily using the magnitude relation between interphase fault impedance and setting impedance to form a criterion; and differentiating a single-phase grounded short circuit fault and a two-phase grounded short circuit fault. When a high impedance grounded short circuit fault occurs on a transmission line at a weak power source side and under the condition that the system operation mode is changed greatly, the method is high enough in phase selection sensitivity, the specific grounded fault phase can be accurately judged, the method is applicable to the fault phase selection of the whole fault process of the transmission line grounded short circuit fault, and is applicable to the fault phase selection of a climbing transmission line high impedance grounded short circuit, and accurate and reliable fault phase information can be provided for distance protection and automatic reclosing lock correct operation.
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Description

technical field

[0001] The invention relates to the technical field of electric power system relay protection, in particular to a method for realizing line grounding fault phase selection by utilizing sequence voltage phase characteristics. Background technique

[0002] Phase selection methods for transmission line faults mainly include phase selection of phase current mutation, phase selection of phase voltage mutation and comprehensive phase selection of voltage and current mutation. On the weak power supply side, the phase selection sensitivity of phase current mutation is not high enough; on the strong power supply side, the phase selection sensitivity of phase voltage mutation is insufficient; although the comprehensive phase selection method of voltage and current mutation has relatively high Good phase selection sensitivity, but there is insufficient sensitivity in phase selection for three-phase short-circuit faults. Since the methods of phase-current sudden change ...

Examples

Embodiment Construction

[0017] The technical solution of the present invention will be further described in detail according to the accompanying drawings.

[0018] figure 1 It is a schematic diagram of the line transmission system applying the present invention. figure 1 CVT is a voltage transformer, and CT is a current transformer. The protection device samples the voltage of the voltage transformer CVT and the current waveform of the current transformer CT at the installation place of the transmission line protection to obtain the instantaneous value of the voltage and current, and then the protection device uses the Fourier algorithm for the collected instantaneous value of the voltage and current Calculation of Zero Sequence Voltage at Transmission Line Protection Installation , Phase A negative sequence voltage , Phase A voltage , Phase B voltage , Phase C voltage and A current , Phase B current , Phase C current .

[0019] Protection device judgment and >l set x 1 Whethe...