Method for analyzing vibration force of power cable fault point

Abstract

The invention discloses a method for analyzing vibration force of a power cable fault point. The method comprises the following steps that firstly, a 110kVXLPE insulating power cable fault point serves as an ideal model, a fault point air gap is a cylindrical air gap with the radius being r and the height being h, and the weight of the fault point air gap can be estimated according to the density of ideal gas; secondly, a high-voltage pulse generator produces a secondary fault at the fault point, and it is assumed that energy is completely converted into internal energy of gas in the cable air gap; thirdly, other internal energy is instantly increased and expanded to act on the outside, and then a power cable relatively moves. The cable is changed into the state shown in the graph 2 from the state shown in the graph 1. On the premise that the energy conservation of the fault section of the cable in the ideal model is taken into consideration, average stress of a vibration section of the fault point of the cable is worked out based on the energy conservation and momentum conservation law. The method has the advantages that the purpose of calculating the impact force of discharging vibration is effectively achieved under the high-voltage pulse action of the power cable fault point.

Description

technical field [0001] The invention relates to a technique for studying the vibration force of a power cable grounding fault, in particular to a method for analyzing the vibration force of a power cable fault point. method of force. Background technique [0002] At present, there is no special calculation method applicable to the single-phase short-circuit ground fault vibration force of 110kVXLPE power cables in the world. Since most power cables are laid underground, single-phase short-circuit ground fault is the most common fault mode of power cables. Once a high-voltage power cable fails, it will cause large-scale power outages and affect the orderly development of social economy. This requires the power sector to quickly find the fault point and implement emergency repairs as soon as possible after the high-voltage power cable fails. Many of the methods for finding single-phase short-circuit fault points in power cables are based on non-electrical measurement princip...

AI Technical Summary

Problems solved by technology

Many of the methods for finding single-phase short-circuit fault points in power cables are based on non-electrical measurement principles, such as the accurate positioning method based on the acoustic wave method of fault point vibration and the method of measuring fault point vibration based on the principle of distributed optical fiber Rayleigh scattering. In the method, due to the attenuation of the vibration signal and the precision requirements of the measuring instrument, many problems have arisen in the measurement and location of the fault point of the high-voltage power cable. At present, there is no effective method to calculate the vibration force of the single-phase fault point of the 110kVXLPE power cable at home and abroad.

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