Distribution network traveling wave fault positioning method based on multi-terminal data

Abstract

The invention discloses a distribution network traveling wave fault positioning method based on multi-terminal data. A terminal node of a used measurement terminal is located at a tail end position of each branch of the distribution network. The method comprises steps: the fault initial wave front time of each terminal node is calculated; according to the fault initial wave front time of each terminal node and the length of a branch circuit, the fault initial wave front time of each virtual node corresponding to each terminal node on a trunk circuit is calculated; according to the wavelet transform modulus value of each terminal node, the fault initial wave front time of each virtual node and the circuit length data, a reference node on the trunk circuit is determined; according to the fault initial wave front time of adjacent two virtual nodes of the reference node and the circuit length data, whether a fault point is in the trunk circuit or the branch circuit is judged; and the position of the fault point is calculated. According to the method of the invention, fault in the trunk circuit and the branch circuit can be accurately positioned, and the system has high reliability.

Description

technical field [0001] The invention relates to a method for locating traveling wave faults of distribution networks based on multi-terminal data. Background technique [0002] 3 ~ 66kV medium and low voltage distribution network mostly adopts the operation mode of ungrounded neutral point or grounded through arc suppressing coil (collectively referred to as small current grounding system). The low-current grounding system has high power supply reliability, low fault current amplitude, and can continue to operate for a certain period of time after a fault. However, due to the weak fault current and complex line structure, it is difficult to locate the distribution network after a fault. [0003] At present, the main research direction in the field of distribution network fault location is fault section location, which can be divided into two categories according to different principles: active fault location and passive fault location. [0004] The basic principle of the ac...

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Problems solved by technology

[0005] The active fault location method is mainly used to locate the fault branch, but cannot accurately locate the fault point, and the equipment is complex and costly, so it is not suitable for long-distance lines, especially the signal generation equipment still has certain safety hazards in operation

[0006] Passive fault location methods include: using FTU or fault indicators, etc., but there are the following problems: the system cost is high, and it needs to be laid out step by step; and it is greatly affected by the fault type and fault transition resistance

[0009] (1) The complex line structure of the distribution network, there are a large number of T-connections

If the traditional double-ended method is used, a large number of sampling terminals are required to be deployed, and sampling terminals are mostly arranged on the main line, so it is impossible to locate the fault of the branch line

At the same time, a large number of T connections also lead to serious attenuation of the traveling wave signal and severe waveform distortion, which reduces the accuracy of wave head recognition and increases the probability of bad data.

[0010] (2) Limited by device cost and on-site installation conditions, the reliability of terminal devices installed on site is relatively low, and the probability of GPS missing satellites and abnormal sampling is high

[0011] Generally speaking, the above factors affect the accuracy and reliability of the distribution network traveling wave fault location system, and limit its practical application.

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