基于离子运动和离子扩散效应的电解电容建模

Electrolytic capacitor modeling based on ion movement and ion diffusion effects

电解电容器是电力电子电路中最薄弱的环节,电解电容器的状态监测对于电路系统的设计和分析具有重要意义。针对电解电容器状态监测问题,跟踪等效串联电阻(ESR)可以很好地反映电解电容器的健康状态。在传统电解电容器模型基础上,考虑电容器在工作过程中的离子运动和离子扩散现象,引入分数阶环节,建立新的分数阶等效电路模型。同时使用差分进化(DE)算法对分数阶模型进行参数辨识,跟踪ESR和阻抗Z的变化,并在Matlab中将传统等效电路模型与改进后的模型进行仿真比较。仿真结果表明,改进的电解电容器等效模型是有效的,其减少了预测误差,提高了监测精度。

The electrolytic capacitor is the weakest one in power electronic circuit.The state monitoring of the electrolytic capacitor is of great significance to the design and analysis of circuit systems.For the condition monitoring of electrolytic capacitors,to track equivalent series resistance(ESR)can well reflect the healthy state of electrolytic capacitors.On the basis of the traditional models of electrolytic capacitors,a new fractional order equivalent circuit model is established by introducing fractional order and considering the ion movement and diffusion phenomena in the working process of capacitors.The differential evolution(DE)algorithm is used to identify the parameters of fractional order model,track the changes of ESR and impedance(Z),and execute simulation comparison between the traditional equivalent circuit models and the improved model in Matlab.The simulation results show that the improved equivalent model of electrolytic capacitor is effective,can reduce the prediction error and improve the monitoring accuracy.