Recognition and location method of oscillatory wave partial discharge in asynchronous double-ended power cable

Abstract

The invention discloses an oscillation wave partial discharge identifying and positioning method for an asynchronous double-end power cable. The method disclosed by the invention comprises the following specific steps: respectively installing oscillation wave partial discharge signal acquisition devices at the two ends of the cable; obtaining the voltage and partial discharge capacity signals at the two ends of the detected cable through data acquisition; recording and converting the corresponding data to obtain a waveform file which is needed for failure positioning; calling a partial discharge positioning algorithm to carry out the failure positioning; and computing the accurate position of a failure point generating partial discharge signals. The positioning analysis result obtained by the invention is more accurate; the error rate is small; the wave velocity does not need to be known, thereby reducing the errors caused by computing the wave velocity; the excessive manual intervention is needed; the problems of large data quantity, inaccuracy in positioning and the like because different pulses under the voltage of each experiment are matched are avoided; and the rapid and accurate failure positioning course of the method is beneficial to the timely repair of faulty lines and the reduction of loss caused by power failure.

Description

technical field [0001] The invention belongs to the field of power systems, relates to power system signal processing application technology, in particular to an asynchronous double-ended power cable oscillation wave partial discharge identification and positioning method. Background technique [0002] Power cable fault location is an important measure to ensure the safe and economical operation of the power grid. Due to the concealment of power cable lines and the limitations of detection equipment, the rapid and accurate location and search technology of fault points is not yet perfect. [0003] At present, there are mainly the following methods used in power cable fault location at home and abroad: traveling wave fault location, energy search algorithm fault location, double-terminal traveling wave location method and GPS fault traveling wave location method, etc. Among them, the fault location of the traveling wave method needs to match the incident wave and the reflect...

AI Technical Summary

Problems solved by technology

Among them, the fault location of the traveling wave method needs to match the incident wave and the reflected wave. Since the signals collected during the transmission of the cable include the incident wave, the reflected wave, the reflected wave of the incident wave, the reflected wave of the reflected wave and other interference Signal, so the incident wave and reflected wave generated by the same partial discharge point are difficult to match correctly; while the positioning method based on the energy search algorithm, the positioning error is centimeter level, but when the partial discharge signal propagation path occurs refraction and reflection, The effectiveness of this positioning method is poor; the double-terminal traveling wave positioning method is based on the initial traveling wave generated by the detection of faults at both ends of the line, and the fault distance is obtained by calculation using the time difference of the traveling wave arriving at both ends and the wave velocity. The main defects of the method are: The problem of time synchronization must be solved; the GPS fault traveling wave positioning method is an ideal time synchronization technology. Using the synchronous clock output of GPS, the time synchronization of the positioning devices at both ends is accurate to one microsecond. Communication link and GPS system to achieve time synchronization, the investment cost is relatively high, and when used in oscillatory wave signal acquisition devices, it needs to be carried out indoors, and indoor GPS signals are weak or even unreceivable

[0004] All of the above methods have measurement errors and large limitations to varying degrees, difficulty in matching incident waves and reflected waves, inability to determine the precise position of partial discharge in power cables, and high costs, which limit their application in the detection of partial discharge in power cable oscillatory waves. Further applications in the field

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