A method for real-time detection of heating of overhead line fittings joints

Abstract

The invention discloses a method of detecting overhead line fitting joint heating in real time and belongs to the electric power system automation technology field. In the invention, based on a power transmission line equivalence impedance principle, through an alternating current resistance tester, a line-measurement alternating current resistance value is acquired. Based on a thermal equilibrium principle, through an environmental parameter and a line current, lead temperature data is acquired in real time. Through distinguishing a three-phase current balance condition, on a lead temperature-line alternating current resistor plane, contact resistances of each fitting during operation are acquired by using a mode of directly comparing or firstly carrying out straight-line fitting and then comparing the alternating current resistance values. Based on a temperature rise relation of the contact resistances and the joint, a phase line where the heating joint is located is positioned and a joint heating degree is determined. A fitting joint heating condition of a three-phase overhead transmission line can be determined in an on line mode, a heat defect fault can be rapidly and accurately positioned, heat defect degree information is analyzed and fed back, line operation reliability is increased and an auxiliary decision-making effect is achieved aiming at increasing an online carrying capacity of the line.

Description

technical field [0001] The invention belongs to the technical field of electric power system automation, and in particular the invention relates to a method for real-time detection of heating of an overhead line fitting joint. Background technique [0002] High voltage, extra high voltage, and extra high voltage transmission lines will have contact resistance on the contact surface when the wires are connected. If the contact is good, the contact resistance is small, which has little influence on the circuit. If the connection is not strong or the contacts are not in good contact due to other reasons, it will cause heat due to large contact resistance, which will intensify the oxidation of the contact surface, make the contact resistance continue to increase, the heat will be more intense, and the temperature will continue to rise, resulting in a vicious cycle. Discoloration or even melting of the metal at the connection point may result. Therefore, it is of great signific...

AI Technical Summary

Problems solved by technology

If the connection is not strong or the contacts are not in good contact due to other reasons, it will cause heat due to large contact resistance, which will intensify the oxidation of the contact surface, make the contact resistance continue to increase, the heat will be more intense, and the temperature will continue to rise, resulting in a vicious cycle. Discoloration or even melting of the metal at the connection point

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