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Circuit model-based single-phase earth fault section location method

A single-phase-to-ground fault, segment location technology, applied in the fault location, fault detection by conductor type, measurement devices, etc., can solve the difficulty of zero-sequence current single-phase-to-ground fault segment location, and cannot determine power distribution deterministically Network fault location, increase professional equipment and other issues, to achieve high economic value and social significance, reduce the scope of location, improve the effect of reliability

Active Publication Date: 2018-09-14
STATE GRID FUJIAN ELECTRIC POWER CO LTD +2
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, for the system where the neutral point is grounded through the arc-suppression coil, the weak and uncertain zero-sequence current makes it difficult to locate the single-phase ground fault section. The method can make the characteristics of the single-phase ground fault between the two data acquisition devices obvious, and then realize the section location of the single-phase ground fault, but this kind of method requires additional professional equipment
At present, the zero-sequence transient power method, zero-sequence transient current amplitude method, zero-sequence current waveform correlation method, etc., which use the characteristics of electrical quantity changes during single-phase ground faults to realize the location of single-phase ground fault sections, are subject to many practical applications in the field. Due to the influence of various factors, it is still impossible to determine the location of the fault section of the distribution network with certainty. If there is strong interference, human auxiliary analysis is still required for judgment.

Method used

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  • Circuit model-based single-phase earth fault section location method
  • Circuit model-based single-phase earth fault section location method
  • Circuit model-based single-phase earth fault section location method

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Embodiment Construction

[0027] The present invention will be described in further detail below in conjunction with the accompanying drawings and specific embodiments.

[0028] This embodiment includes the following steps:

[0029] (1) When a single-phase ground fault occurs somewhere in the distribution network, according to the data of the fault recording device (usually the transient fault recording device TFR), the bus at the power supply end of the area (denoted as M terminal, The fault zero-sequence voltage u of the next monitoring point far away from l is marked as N terminal) M0 and zero sequence current i M0 The sampling value of .

[0030] (2) Using the Mcquart method, the zero-sequence voltage u M0 and zero sequence current i M0 The discrete sampled values ​​are fitted to obtain the continuous time function u M0 (t), i M0 (t).

[0031] (3) Using the distributed parameter circuit model:

[0032] A section of single-phase line is regarded as composed of infinitely many microelements c...

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Abstract

The invention provides a circuit model-based single-phase earth fault section location method, which comprises the following steps: in case of a single-phase earth fault at a certain position in a power distribution network, acquiring sampling values of a zero sequence voltage uM0 and a zero sequence current iM0 of the fault of a bus position (which is recorded as M end, and a next monitoring endaway from the M end by 1 is an N end) of a power supply end of the region according to data of a fault recording device; fitting the discrete sampling values of the zero sequence voltage uM0 and the zero sequence current iM0 by using the maquart method to acquire continuous time functions uM0(t) and iM0(t); calculating a zero sequence voltage uN0(t)c and a zero sequence current iN0(t)c of the nextmeasurement point N which is 1 away by using a distributed parameter circuit model; respectively comparing the calculated zero sequence voltage uN0(t)c and zero sequence current iN0(t)c of the N endwith a zero sequence voltage uN0(t) and a zero sequence current iN0(t)c which are obtained by sampling and fitting at the position N, and if the voltages and the currents are consistent, determining that the MN section is not a fault section, and continuously searching the next line; if the voltages and the currents are not consistent, determining that the MN section is a fault section. The methodcan locate a single-phase earth fault section on the basis of not increasing the hardware investment.

Description

technical field [0001] The invention belongs to the field of daily maintenance of electric power, and in particular relates to a criterion and a method for realizing the location of a single-phase ground fault section of a distribution network based on a line model. Background technique [0002] At present, most of the section location methods for distribution network faults are realized through the data acquisition devices installed on the lines. For single-phase ground fault, for the neutral point grounded by small resistance or neutral point ungrounded system, through the comparison of two adjacent zero-sequence currents on the line, it can be clearly judged whether the single-phase ground fault occurs in the two data between acquisition devices, so the above method is available. However, for the system where the neutral point is grounded through the arc-suppression coil, the weak and uncertain zero-sequence current makes it difficult to locate the single-phase ground fa...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G01R31/08
CPCG01R31/086G01R31/088
Inventor 郑欢林红阳唐元春林文钦陈力梁开栋柏强李扬森冯波
Owner STATE GRID FUJIAN ELECTRIC POWER CO LTD
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