Fault section location method of distribution network based on differential offset degree

A line fault and section positioning technology, applied in the direction of fault location, information technology support system, etc., can solve problems such as failure, complex information acquisition, and high requirements for transformers, and achieve weak fault current, simple data acquisition, and strong applicability Effect

CN104865496BInactive Publication Date: 2018-02-13STATE GRID CORP OF CHINA +2
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Patents(China)
Current Assignee / Owner
Publication Date
2018-02-13
Estimated Expiration
Not applicable · inactive patent

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Abstract

The invention discloses a distribution network line fault segment positioning method based on differential offset degree. An earth fault is positioned through analyzing the phase current characteristics of a fault phase current before fault occurrence and during the period from fault occurrence to action of an arc extinguishing coil, extracting a fault characteristic quantity from the phase current characteristic and utilizing the full-course waveform differential offset degree. The distribution network line fault segment positioning method only requires measurement for the fault phase current of the line and has advantages of simple solution and high applicability. The distribution network line fault segment positioning method can well settle problems of weak fault current, low reliability and low sensitivity which commonly exist in single-phase earth fault of a small-current earth system. Furthermore an interference to the system is prevented.
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Description

technical field

[0001] The invention relates to a method for diagnosing a distribution network line fault, in particular to a method for locating a distribution network line fault section based on a differential offset degree. Background technique

[0002] According to statistics, during the operation of the power system, power outages caused by distribution network faults account for more than 95% of the total power outages, of which 70% are caused by single-phase ground faults or busbar faults. The neutral point of domestic and foreign distribution networks widely adopts non-effective grounding (small current grounding) to avoid power supply interruption when a single-phase grounding fault occurs. For single-phase-to-ground faults in distribution networks, due to weak fault characteristics, there has been a lack of reliable fault line selection and location methods. With the improvement of people's requirements for distribution network automation level, it is more urgent ...

Examples

Embodiment Construction

[0055] The fault waveform required by the present invention comes from the distributed fault section positioning system, and the system architecture is as follows figure 2 shown. The distribution network fault section location system consists of a monitoring master station, a substation (busbar) measurement device, and node fault location devices distributed throughout the distribution line. The fault location node divides the line into several sections topologically, and each node installs three sets of measuring devices to collect the three-phase current and voltage of the line synchronously in real time.

[0056] According to the fault location method invented, different types of faults are set in the 10kV distribution network simulation system. The system structure diagram is as follows image 3 As shown, ①, ②, ③ are section numbers, and faults are set on section ②. The sampling frequency is 20kHz (N = 400 data points per cycle), the fault occurrence time is 0.7s, the ...