A Method for Performance Degradation and State Evaluation of AC Contactor

Abstract

The invention belongs to the field of electrical intelligence, in particular to a data-driven AC contactor performance degradation and state evaluation method and system. It can more accurately realize the evaluation of its performance degradation state. The following steps are included: (1) Obtain data from the full-life test system of the AC contactor under AC‑4 conditions, and perform feature extraction on the data. (2) Preprocess the feature parameters. (3) Based on the full life test data, establish the state classification of AC contactors, and divide each contactor state into several groups with the same number of tests according to the test sequence. Each group is established with the breaking current phase angle as the independent variable. (4) Dimensionality reduction is performed on the characteristic parameters of each group in each state. (5) Carry out EMD decomposition to get several IMF components. (6) Establish feature vector matrix. (7) Build a hidden semi-Markov model for each state. (8) According to the evaluation results, the maintenance strategy of the AC contactor is given.

Description

technical field [0001] The invention belongs to the field of electrical intelligence, in particular to a data-driven AC contactor performance degradation and state evaluation method. Background technique [0002] The AC contactor is used to frequently switch on and off the AC main circuit and large-capacity control circuit at a long distance. It is a very versatile and very important low-voltage electrical appliance. The smart grid is an automated power supply network, and each node of it can be monitored in real time. The realization of the intelligence of the AC contactor will promote the development of the smart grid, which is reflected in the monitoring of its real-time working status and its own detection. Normally, the mechanical life of the AC contactor is very long, and the electrical life is much shorter than the mechanical life, which is an important indicator for evaluating the reliability of the AC contactor. The main factor affecting its electrical life is the ...

AI Technical Summary

Problems solved by technology

[0003] At present, there are many methods for evaluating the performance degradation and state of AC contactors. When the contactor is actually running and breaking, the phase angle of the arcing current at each breaking is random. There is no relatively suitable method on how to deal with this problem. The accuracy of the state assessment model needs to be improved

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