Method for detecting interface pressure of medium-voltage cold-shrinkable cable joint

Abstract

The invention provides a method for detecting the interface pressure of a medium-voltage cold-shrinkable cable joint, which includes the following steps: S1, preparing and installing a test platform and sensors: selecting a number of cable core samples with standard cross sections according to the specification of the cable joint, wherein each cable core sample is equipped with a thin film pressure sensor; S2, installing the cable joint: installing the cable joint on the cable core sample with the smallest standard cross section, and allowing the cable joint to retract and become stable; S3, measuring the interface pressure: measuring the interface pressure of the cable joint by the corresponding thin film pressure sensor; S4, after the measurement in S3, pushing the cable joint to the next cable core sample with a standard cross section to test the distribution of the internal interface pressure of the cable joint; and S5, recycling the cable joint: after all tests are completed, connecting the cable core sample with the largest cross section with a support sleeve, and pushing the cable joint to the support sleeve through a hydraulic press to restore the cable joint to an unused state.

Description

technical field [0001] The invention relates to a method for detecting a cable joint, in particular to a method for detecting the interface pressure of a medium-pressure cold-shrinkable cable joint. Background technique [0002] At present, in the distribution network of most cities in my country, the intermediate joint of the cable is widely used to extend the length of the cable line and maintain the continuity and integrity of the cable, which plays a key role in the distribution network cable line. Among them, the cold shrink joint has been widely used because of its small size and convenient installation. However, a large part of the faults of today's cable lines often occur on the intermediate joints, and the parameters such as the sealing performance and dielectric strength of the intermediate joints are closely related to the interface pressure of the intermediate joints. This requires accurate measurement of the interface pressure of the cold-shrinkable intermediat...

AI Technical Summary

Problems solved by technology

[0004] Some researchers and manufacturers complete the entire connection process of the real cable after installing the sensor on the interface of the cold-shrinkable cable joint, and then read the interface pressure of the cable joint. There are also many materials and tools, which cannot achieve the purpose of simple and convenient measurement of the interface pressure of the cable joint

Some researchers have also proposed to use photoelastic materials or aluminum tubes to simulate cable joints, but these simulations can not fully reflect the interface pressure of real cold-shrinkable cable joints.

There are also researchers who use simulation tests to calculate the interface pressure of cold-shrinkable cable joints through finite element simulation, but the simulation model is too idealized to perfectly simulate the actual cable joint situation, and the results are not convincing.

[0005] The cable section that can be matched by the medium voltage cable joint often has a certain range, and when the cable is installed with the joint, there are structures of semi-conductive fracture, joint fracture and crimping tube, and its outer diameter is not consistent with the cable. The interface pressure requirement is more stringent, if the pressure is insufficient, the electric field will not be uniform or the electric strength will be reduced

Images