A Fractional Equivalent Circuit Model of Electrolytic Capacitor and Its Parameter Identification Method

Abstract

A fractional-order equivalent circuit model of an electrolytic capacitor and its parameter identification method. The equivalent circuit model includes the capacitor terminal foil joint resistance R 0 , Electrolyte resistance R 1 , the resistance R generated by ion movement and ion diffusion d , Fractional capacitance generated by ion movement and ion diffusion, terminal capacitance C t , Dielectric loss resistance R 2 , Dielectric loss capacitance C 1 . Where: α,R 0 , R 1 , R d ,C 1 , R 2 is the parameter to be identified; the parameter identification is performed by the fractional-order multi-objective offline parameter identification method based on the differential evolution algorithm. The present invention introduces the prediction of the equivalent capacitance value on the basis of the traditional research on ESR, so that the prediction is more comprehensive. In terms of fitting algorithm, the traditional differential evolution algorithm is improved. It provides a reference basis for circuit system design and reliability analysis containing such components.

Description

technical field [0001] The invention relates to the technical field of electrolytic capacitor monitoring and modeling, in particular to a fractional-order equivalent circuit model of an electrolytic capacitor and a parameter identification method thereof. Background technique [0002] Capacitors are indispensable basic components in electronic circuits. Electrolytic capacitors are widely used in filter circuits, automotive regulated power supplies, DC-DC converters and power electronics applications, accounting for about 40% of the total consumption of electronic components. It is widely used in all aspects of human life. However, its failure rate is the highest among power electronic devices. Therefore, monitoring and modeling the state of electrolytic capacitors is of great significance, with profound implications for the service life of the components, maintenance costs, and the safety of related applications. [0003] An increase in the equivalent series resistance (ES...

AI Technical Summary

Problems solved by technology

Most of the existing capacitor equivalent models are based on simple series-parallel connections of resistors and capacitors, and are modeled in the range of integer orders. There are problems such as low accuracy and lack of analysis of various phenomena caused by component parameter changes.

To a certain extent, it affects the monitoring of capacitor status, and even increases the probability of missing failure predictions for applications containing capacitors

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