高频下功率模块有机硅凝胶封装材料中电树枝生长及自愈特性  

Electrical Trees Growth and Self-healing Properties in Silicone Gel Encapsulation Materials for Power Module at High Frequencies

作　　者：王健 陈晨 闫豪生 李志辉 王伟[1] 邹亮[2] 张黎[2] 李庆民 WANG Jian;CHEN Chen;YAN Haosheng;LI Zhihui;WANG Wei;ZOU Liang;ZHANG Li;LI Qingmin(State Key Lab of Alternate Electrical Power System with Renewable Energy Sources(North China Electric Power University),Changping District,Beijing 102206,China;School of Electrical Engineering,Shandong University,Jinan 250061,Shandong Province,China)

机构地区：[1]新能源电力系统国家重点实验室(华北电力大学),北京市昌平区102206 [2]山东大学电气工程学院,山东省济南市250061

出　　处：《中国电机工程学报》2024年第10期4134-4144,I0033,共12页Proceedings of the CSEE

基　　金：国家重点研发计划项目(2021YFB2601404);国家自然科学基金项目(52077127)。

摘　　要：有机硅凝胶因其良好的电、热及机械性能,被广泛应用于多能变换装备中功率模块的封装绝缘,电树枝是由于局部放电而产生的树枝状放电通道,是功率模块封装绝缘系统较为常见的失效形式。基于此,该文搭建高频正弦电压激励下有机硅凝胶中电树枝生长实验平台,开展不同频率下的电树枝生长实验,探究高频下有机硅凝胶中电树枝的起始及传播机制,分析频率对电树枝特性的影响机理;进一步开展不同温度以及组分配比下的电树枝自愈实验,研究有机硅凝胶中电树枝自愈行为及其影响机制。实验结果表明,随着频率的升高,硅凝胶中电树枝形态将更加复杂,起树电压也会随之下降,18kHz下起树电压较8kHz下降了约17%。分析认为,麦克斯韦应力是导致高频下电树枝起始的主要原因,而有机硅凝胶中电树枝的传播特性也有别于传统固体电介质。针对自愈特性,温度升高有利于电树枝的自愈,但在100℃下将会抑制自愈,分析得到温度通过影响气体状态来影响自愈的不同阶段。同时,组分配比不同也会影响硅凝胶的形态及电树枝特性。Silicone gel is widely used in the package insulation of power module because of its good electrical,thermal and mechanical properties.Electrical trees are dendritic discharge channels due to partial discharges,constituting a prevalent failure mode in power module package insulation systems.On this basis,this paper builds an experimental platform for the growth of electric trees in silicone gel under high frequency sinusoidal voltage excitation,conducts experiments on the growth of electric dendrites at different frequencies,investigates the initiation and propagation mechanism of electric dendrites in silicone gel under high frequency,and analyzes the influence mechanism of frequency on the characteristics of electric trees.It also conducts experiments on the self-healing of electric trees at different temperatures and group distribution ratios,and investigates the self-healing behavior of electric trees in silicone gel and its influence mechanism.The self-healing behavior and its influence mechanism are investigated.The experimental results show that with the increase of frequency,the electric trees morphology in silica gel will be more complex and the starting voltage will also decrease,and the starting voltage at 18 kHz is about 17%lower than that at 8 kHz.The analysis suggests that Maxwell stress is the main reason for the initiation of electric trees at high frequencies,and the propagation characteristics of electric trees in silicone gels are different from those of conventional solid dielectrics.For the self-healing characteristics,the increase of temperature is favorable to the self-healing of the electric trees,but it will inhibit the self-healing at 100°C.The analysis obtains that the temperature affects the different stages of self-healing by influencing the gas state.Also,the composition ratio affects the morphology of the silica gel and the electrical tree properties.

关 键 词：有机硅凝胶 电树枝 自愈特性 功率模块 

分 类 号：TM215[一般工业技术—材料科学与工程]