A phase selection method for transmission line ground faults against the influence of distributed capacitive current and transition resistance

A transmission line and distributed capacitance technology, applied in fault location, fault detection according to conductor type, measurement of electricity, etc., can solve the problem of insufficient phase selection sensitivity of phase voltage sudden change, phase selection of three-phase short-circuit fault and high-resistance grounding short-circuit fault sensitivity Insufficient, phase current mutation amount is not enough phase selection sensitivity, etc., to achieve the effect of high phase selection sensitivity, correct and reliable fault phase information

CN105699852BInactive Publication Date: 2018-10-19STATE GRID FUJIAN ELECTRIC POWER CO LTD +2
9 Cites 0 Cited by

Patent Information

Authority / Receiving Office
CN · China
Patent Type
Patents(China)
Current Assignee / Owner
Publication Date
2018-10-19
Estimated Expiration
Not applicable · inactive patent

Smart Images

  • Figure 1
    Figure 1
Patent Text Reader

Abstract

The invention discloses a power transmission line grounding fault selection method capable of resisting distributed capacitive current and transition resistance effect. According to the power transmission line grounding fault selection method, a distributed parameter model is used as a physical model; phase relationship between a zero-sequence voltage difference and an A-phase negative-sequence current vector sum and phase relationship between the zero-sequence voltage difference and the A-phase positive-sequence current vector sum are utilized for forming a power transmission line grounding fault phase selection criteria, thereby accurately determining the type of a power transmission line grounding shortcircuit fault. According to the method of the invention, a distributed parameter model is used as the physical model; the method of the invention has natural capability for resisting the distributed capacitive current effect, and is suitable for superhigh-voltage and ultrahigh-voltage power transmission line. When high-resistance grounding shortcircuit fault occurs on condition that relatively large change of a weak power supply side and a system operation mode occurs. According to the method of the invention, a high-enough phase selection sensitivity is realized in the whole fault process of power transmission line grounding fault. A particular grounding fault phase can be accurately determined. Accurate and reliable fault phase information can be supplied for distance protection and correct action of an autoreclose circuit breaker.
Need to check novelty before this filing date? Find Prior Art

Description

technical field

[0001] The invention relates to the technical field of relay protection for power systems, in particular to a phase selection method for transmission line grounding faults against the influence of distributed capacitive currents and transition resistances. 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 The sensitivity of phase selection is good, but the sensitivity of three-phase short-circuit fault phase selection and high-resistance grounding sh...

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 The middle CT is a current transformer, and the CVT is a voltage transformer. The protection device measures the zero-sequence current at the protection installation at the m-end of the transmission line Zero sequence voltage Phase A negative sequence current A phase positive sequence current Phase A negative sequence voltage and A phase positive sequence voltage Measure the zero-sequence voltage at the n-terminal protection installation of the transmission line Phase A negative sequence current A phase positive sequence current

[0019] Protection device judgment and Whether it is established, and if it is established, the protection device judges that a single-phase ground short-circuit fault has occurred in ...