Power distribution network fault positioning system and method based on transient information

Abstract

The invention discloses a power distribution network fault positioning system and method based on transient information. The system comprises a positioning master station which is installed in a transformer substation, collects the electrical information collected by each IED, and carries out the analysis through fault positioning software to judge a section where a fault is located; and intelligent IED equipment which is arranged at measuring points of a line in a power distribution network and is used for fault detection. The system is composed of the positioning master station and the intelligent IED equipment which communicate through a light Ethernet, and when a protected line has a grounding fault, the intelligent IED equipment can detect transient electrical quantity and start a fault positioning program of the positioning master station, so that a section where the fault is located is determined. The fault positioning problem that capture of transient quantity characteristics is difficult and easily interfered by noise is solved, a bus fault and a line fault can be effectively identified, the fault positioning accuracy is improved, and a grounding fault of a power distribution network can be rapidly and reliably identified.

Description

technical field [0001] The invention relates to the technical field of power equipment fault detection, in particular to a transient information-based power distribution network fault location system and method. Background technique [0002] With the massive access of power electronic equipment such as flexible DC and distributed power, the topological structure of modern distribution network is complicated, and the operation mode is changeable. Great difficulties and challenges also put forward higher requirements for power grid fault removal and power supply restoration. As a link between the transmission network and users, fault location technology is an important guarantee for improving the safe and stable operation of the system. [0003] At present, the main problems in the fault location of the distribution network are: (1) The steady-state characteristics are weak, and the application of strong background noise and arc suppression coils increases the difficulty of f...

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Problems solved by technology

[0003] At present, the main problems in the fault location of the distribution network are: (1) The steady-state characteristics are weak, and the application of strong background noise and arc suppression coils increases the difficulty of fault identification; it is difficult to capture transient current signals, and three-phase CT synthesis is often used to obtain them. The way to obtain transient zero-mode current, the application of electromagnetic transformer will increase the relative error, which is not conducive to the protection action

(2) It is difficult to accurately synchronize data transmission, and the transient signal exists for a short time, which puts forward higher requirements for the sampling and transmission accuracy of each measuring point

If the data is not uploaded and compared in real time, a delay of 0.5ms may result in different waveform directions

(3) Some methods have poor applicability. For the positioning method using steady-state quantities, due to the small signal amplitude, the discrimination based on the amplitude and phase difference may fail; for the transient quantity positioning method, the amplitude changes rapidly, and the acquisition Not easy, affected by the delay of the data signal, the fault tolerance is insufficient, and there may also be problems of inaccurate positioning

(4) The anti-interference ability needs to be improved. In actual operation, the high-order harmonics in the field environment will affect the detection of fault current

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