A Method and Device for Identifying the Risk of Insulation Aging of Distribution Network Cable Lines

Abstract

The invention provides a method and device for identifying the insulation aging risk of distribution network cable lines. According to the pre-established equivalent circuit model of distribution network cable lines, the method obtains the three-phase voltage, current, Acquisition values ​​of active power and reactive power; calculate T time period and time interval T based on the collected values ​​of voltage, current, active power and reactive power i The leakage current value and the average value of the leakage current in the cable line; determine the leakage current prediction value according to the leakage current value; judge whether the cable line is at the insulation aging risk at the current moment according to the leakage current historical data and prediction data, and the insulation aging risk identification criterion state. The technical solution provided by the invention effectively realizes the real-time monitoring and prediction of the leakage current of the distribution network, can accurately warn the insulation aging risk of the distribution cable line, and provides technical support for the operation and maintenance of the cable line by the power grid operators.

Description

technical field [0001] The invention belongs to the field of electric power systems and automation thereof, and in particular relates to a method and a device for identifying the aging risk of insulation of distribution network cable lines. Background technique [0002] At present, my country is in a period of rapid development of the distribution network. With the increase of the distribution network scale, the user's power load level is increasing rapidly, and the requirements for the reliability of the power grid are also increasing. With the continuous increase of power load, the operating environment of power cables is becoming more and more complex, and because the cables are arranged underground and in shafts, their potential defects and aging are not easy to be found. Decreased flow rate, accelerated insulation aging, lowered insulation level, or short circuit causes power failure or even fire, which seriously spreads to other equipment, resulting in large-scale and ...

AI Technical Summary

Problems solved by technology

[0004] The current insulation aging monitoring methods mainly include DC component method, DC voltage superposition method, partial discharge method, etc.: The DC component method is easily affected by the stray current in the ground, making insulation monitoring inaccurate; the DC voltage superposition method needs to install additional At the same time, due to the influence of stray current, the measurement error is relatively large; although the partial discharge method is currently the most commonly used method in cable insulation monitoring, due to the large interference in actual monitoring, online monitoring of partial discharge is also relatively Difficulties, these methods have certain deficiencies in practical application

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