Method and system for positioning cable fault based on Kalman filtering

Abstract

The invention discloses a method and a system for positioning a cable fault based on Kalman filtering, and belongs to the technical field of cable fault diagnosis. The method comprises the steps of selecting an incident wave and a reference wave of a diagnosis cable according to the length of a to-be-detected cable, and injecting the incident wave into the cable; after the incident wave is injected into the cable, collecting a reflected wave of the incident wave passing through the cable; obtaining the product of the reflected wave and the reference wave, and taking the product as a mixed signal; inputting the mixed signal into a low-pass filter for low-pass filtering processing, and outputting a low-pass filtering signal; constructing a state equation and a measurement equation of a fault position according to the low-pass filtering signal, and constructing state variables for the state equation and the measurement equation; and performing edge filtering processing on the state variable, and positioning the fault of the electric quantity according to the state variable after filtering processing. According to the method, the fault of the cable is accurately positioned, and the method is superior to a time domain waveform reflection method.

Description

technical field [0001] The present invention relates to the technical field of cable fault diagnosis, and more specifically, to a method and system for locating cable faults based on Kalman filtering. Background technique [0002] With the continuous advancement of urban construction, in order to better show the city's appearance, the construction of overhead lines into the ground and other projects will make (superconducting) cables gradually replace traditional lines and become the main force of urban transmission networks. [0003] Due to the structural differences between (superconducting) cables and overhead lines, their fault location methods are very different. The time domain waveform reflection method (TDR) currently used for cable fault location has low positioning accuracy and difficult identification of fault points. The problem, the typical detection results, using the step waveform injected into the cable body, and the detection results obtained through the ref...

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Problems solved by technology

[0003] Due to the structural differences between (superconducting) cables and overhead lines, their fault location methods are very different. The time domain waveform reflection method (TDR) currently used for cable fault location has low positioning accuracy and difficult identification of fault points. The problem, the typical detection results, using the step waveform injected into the cable body, and the detection results obtained through the reflection of the time domain waveform, the location of the fault point is not obvious. When there is a large external noise, the fault location is difficult to detect. Possibility of identification

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