基于ANSYS的金属化膜脉冲电容器放电过程热仿真与分析

Thermal simulation and analysis of discharge process of metallized film pulse capacitor with ANSYS

在金属化膜脉冲电容器放电过程中,脉冲电流通过金属化电极层产生焦耳热量,导致电容器内部温度升高,当温度超过一定值时,电容器可能会受损。该文将脉冲电流强度与电极电流分布规律相结合,计算出脉冲电流通过金属化电极层不同区域的热生成率;采用ANSYS软件对一个金属化聚丙烯膜脉冲电容器的放电过程进行了热仿真分析;其中稳态热仿真结果表明,在脉冲电流重复作用下,最高温度点出现在电容器中心位置,且电容器各部位温度随充放电频率提升而升高;瞬态热仿真结果表明,在峰值为5060 A的单次脉冲放电电流作用下,金属化膜上的最高温升约0.5℃,单次脉冲电流在电极层上形成的温升较低,电容器内部的温升应是脉冲电流重复作用的结果。分析结果揭示了金属化膜脉冲电容器的内部发热规律,对提升脉冲电容器可靠性设计具有一定的参考意义。

During the discharge process of metallized film pulse capacitor,the pulse current produces joule heat through the metalized electrode layer,which increases the internal temperature of the capacitor.When the internal temperature exceeds certain degree,the capacitor might be damaged.In this article,combining the distribution of pulse current and electrode current,the pulse current heating rate from different metalized layers was calculated.The ANSYS software was used for thermal simulation of a metalized polypropylene pulse capacitor discharging process.The steady-state thermal simulation result indicates that,under the affection of the pulse current,the maximum temperature point appears in the center of capacitor and the temperature of capacitor increases with increasing charge and discharge frequency.The transient thermal simulation result indicates that,under single peak 5060 A pulse current,the maximum temperature of the metalized film rises about 0.5℃.And single pulse current caused temperature rising is lower.The internal temperature rising of the capacitor is the result of pulse current affection.This result discloses the internal heating regulation of the metalized film pulse capacitor,and is helpful to improve the reliable design of the pulse capacitor.