Electrical characteristics of high energy density MLC for pulse power application

Abstract

High energy density capacitor is a very important component to supply energy in pulse power source. Owing to its high dielectric constant (up to 10/sup 5/ or more), ceramic material is regarded as a sound dielectric for producing high energy density capacitors. With the energy density under the same order of several hundred J/L, ceramic capacitors can endure higher inverse voltage (>70%) and have longer life (shot times >10/sup 6/) compared with metallized film. Multilayer ceramic capacitors (MLC) of low rated voltage have been used for power decoupling and bypass in telecommunication equipments for many years. In this paper, MCL samples of high voltage have been produced, and their electrical characteristics tested in a pulse energy discharge circuit. From the result, the relations between the changes of capacitance, dielectric loss, the charge frequency, and the lifetime have been deduced. The features in discharge wave are also presented. Some failure mechanisms for these capacitors are put forward in this paper. In conclusion, MLC is suitable for making high energy density capacitor, which can endure high reverse voltage, high current and possesses long lifetime.