Online monitoring method for contact resistance of multiple key contact points in medium-voltage switch cabinet

Abstract

The invention discloses an online monitoring method for the contact resistance of multiple key contact points in a medium-voltage switch cabinet, and relates to the technical field of power equipment.Finite element software is adopted to analyze and solve the temperature rise under different contact resistance distributions. During simulation calculation, the influence of the contact resistance of each point location on the temperature rise can be fully considered by reasonably setting the contact resistance distribution of different point locations. And neural network training is performed by taking data obtained by simulation as a sample, so the accuracy of a neural network prediction result can be ensured. And finite element software is adopted to analyze and calculate the relationshipbetween the temperature rise of each temperature measurement point and the effective value of the load current. Temperature rise data under different loads are calculated through finite element simulation, and the result obtained through the method is accurate. And fitting is performed according to the obtained data, and the obtained relational expression is accurate and reliable. By adopting theprediction method of the neural network, the contact resistance of multiple key points in the switch cabinet can be predicted at the same time, the prediction result is accurate, the process is rapid, and the problem that the contact condition in the switch cabinet cannot be monitored online is solved.

Description

technical field [0001] The invention relates to the technical field of electric power equipment, in particular to an online monitoring method for contact resistance of multiple key contact points in a medium-voltage switchgear. Background technique [0002] With the continuous growth of my country's power generation and electricity consumption in recent years, the output of medium-voltage distribution switchgear has continued to increase, and the continuous development of economy and society has put forward higher requirements for the reliability of medium-voltage switchgear. In recent years, accidents caused by the deterioration of switchgear contact conditions have been emerging. During the operation of the medium voltage switchgear, the contact resistance has a decisive influence on its temperature rise and heat generation. When current flows through the contact, the current line shrinks, and contact resistance occurs. In the switchgear, the contact resistance between t...

AI Technical Summary

Problems solved by technology

This method can measure the size of the contact resistance value of the switchgear, but it has the following disadvantages: 1) The measurement result of the loop resistance tester is the entire loop resistance, which cannot accurately measure the size of the contact resistance value, and there are errors

2) Since the test principle is Ohm's law, the loop resistance tester is only suitable for offline testing and cannot be used for online monitoring

For the switchgear in operation, it needs to be shut down to detect, and the cost is high

3) The loop resistance tester can only test one contact resistance at a time, and the contact resistance in each switch cabinet needs to be tested separately, and the test process is complicated

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