多层陶瓷电容器在脉冲条件下寿命特性的研究

 主要研究了高储能密度多层陶瓷电容器（MLC）在不同充放电频率、充电电压、充放电占空比和放电反峰系数等条件下的寿命特性，并对其失效机理进行分析。实验发现，正常情况下MLC试品的击穿需要经过局部放电通道不断发展，绝缘逐渐被破坏的过程，寿命较长，发热和试品内部的交变应力是推动局部放电通道不断发展的根本因素。充放电频率的升高使试品发热加剧，寿命缩短；充电电压和放电反峰系数的增大使发热和介质内应力加剧，可以使寿命缩短90％以上。改善散热可以有效提高试品寿命，如当充放电频率为136 Hz时，采用油浸散热比空气自然换流散热寿命延长300％。

Life characteristic of multilayer ceramic capacitors under pulse conditions

This paper mainly discusses the life characteristic and failure mechanism of the multilayer ceramic capacitor(MLC) under various working conditions such as charge-discharge frequency,charge voltage,charge-discharge duty radio and discharge inverse peak factor.Experiments discover that the breakdown of MLC is the result of continuous extending of partial discharge.Exothermicity and alternating internal stress are the key factors which make partial discharge channels keep on growing.The increase of charge-discharge frequency shortens the life of MLC by accelerating the heat production.The increase of charge voltage and discharge inverse peak factor make the life of MLC over 90% shorter by enhancing both heat production and internal stress of the dielectric.An effective method to increase the life of MLC is to improve the way of heat dispersion.Dipping in oil makes the MLC have a life of 300% longer than that of only exposing in air under the frequency of 136 Hz.