Pre-twisted wire breakage contact resistance experimental measuring method based on thermoelectric conversion

Abstract

The invention discloses a pre-twisted wire breakage contact resistance experimental measuring method based on thermoelectric conversion. The method comprises the following steps: obtaining an accuratethermal parameter by calculation; according to the thermoelectric analogy theory and the temperature heat balance principle, establishing a heat circuit model for a ground wire and the pre-twisted wire fracture; designing a temperature rise experiment to obtain the temperature distribution of discrete points in the axial direction of the ground wire and the pre-twisted wire fracture; according tothe established heat circuit model and the temperature distribution of discrete points obtained by the temperature rise experiment, calculating the contact resistance of the ground wire and the interior of the pre-twisted wire fracture. The method of the invention obtains the AC contact resistance, can effectively avoid the magnetic field interference encountered by an electrical measurement method, only needs to detect the temperature distribution of discrete points of the overall structure, does not need to detect the impedance angle for the detection of AC resistance, requires less apparatus, facilitates online monitoring, and has significance of universal promotion and use.

Description

technical field [0001] The invention relates to the technical field of ground wire measurement, in particular to an experimental measurement method for contact resistance at a fracture of a pre-twisted wire based on thermoelectric conversion. Background technique [0002] The occurrence of disconnection accidents due to overheating of the ground wire often leads to power outages in large areas of the power grid, and even leads to secondary disasters, seriously affecting the safe and stable operation of the power grid and personal safety. Existing studies have shown that the ground wire suspension string (structure such as figure 1 As shown) the inside of the pre-twisted wire fracture is a major heating "bottleneck" point, and the contact resistance is an important factor leading to the disconnection of the ground wire. Therefore, the accurate measurement of the internal contact resistance of the pre-twisted wire fracture is an important basis for studying and analyzing its ...

AI Technical Summary

Problems solved by technology

If this method is implemented in the form of AC, there are two problems as follows. One is that it is necessary to introduce detection equipment and instruments such as oscilloscopes and other impedance angles to obtain the phase difference between the measured current and voltage.

The second is that the alternating current generates a magnetic field in the surrounding space, causing interference to the voltage measuring equipment

[0004] Based on this, it is necessary to solve the problems that the above-mentioned existing experimental measurement methods cannot obtain AC contact resistance, and at the same time avoid the introduction of instruments such as oscilloscopes for detecting impedance angles, and propose an experimental measurement method for contact resistance at the fracture of pre-twisted wire based on thermoelectric conversion

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