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ABSTRACT: When metallized capacitors are applied to pulsed power applications with frequency less than 1 Hz, heat induced by current can be ignored. However, it is necessary to consider the accumulation effect of heat on temperature rise of capacitors which are applied to repetitive pulsed systems. The paper mainly study the influence of frequency and line current density on temperature rise of metallized capacitors applied to repetitive pulsed systems. The experiment results show that temperature increases with line current density and frequency increasing, and when surface temperature of capacitor is higher than 110degC, the melted PP film would blow out from the middle location of capacitors, and the highest temperature in the capacitor is calculated. The capacitor segment location and line current density on the single discharge energy of the capacitor are influenced and has been analyzed by ATP. Temperature rise of each segment location of capacitor caused by single discharge was calculated, the results show that temperature rise is very small.
IEEE Transactions on Dielectrics and Electrical Insulation 09/2009; · 1.09 Impact Factor
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ABSTRACT: High energy density capacitor is a key device in power supply source in electromagnetic gun (EMG) system. The increase of energy density of capacitor is beneficial from emerge of metallized technology in electrode and advancement in manufacturing. The paper studies a kind of high energy density capacitor made of polypropylene with metallized electrode. The self-healing ability is improved by optimization of the structural parameter of the metal electrode. First, aimed to be used in EMG, experiments such as lifetime test and voltage withstand test are carried out to study the performance of the capacitor. The metallized film capacitor has an energy density of 1.6 J/cm<sup>3</sup> under 10 kV. And the lifetime test finds its lifespan of 2000 shots. Then, the influences of different impregnating materials on the voltage drop are compared in the paper for manufacture improvement purpose. Last, voltage maintaining test are carried out to observe the voltage drop of the capacitor. The output precision of the launch system will be consequently influenced. In order to obtain a stable voltage, a constant current and micropower charge control technique is applied to realize fast and high accuracy charge of capacitor to avoid fluctuation of output energy. Using micropower charge control, the voltage deviation in maintaining stage is less than plusmn1<sup>0</sup>/<sub>00</sub>. And the charge system has a repeat accuracy of 0.520<sup>0</sup>/<sub>00</sub> with high reliability.
Electromagnetic Launch Technology, 2008 14th Symposium on; 07/2008
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ABSTRACT: The pressure intensity between layers of capacitors is related to capacitor’s self-healing characteristics. This paper describes how to calculate the pressure intensity between the layers of capacitors before and after heat treating, and the influence of the pressure on inter-metallized and aluminum-metallized layers in the process of self-healing. The experiment results indicate that with the increase of pressure the diameter of self-healing point and the energy consumed in this process decrease. But diameter, energy and voltage tend to be stable after the pressure has reached a certain value. The diameter and energy of self-healing point are larger in aluminum-metallized layers than those in inter- metallized layers.
Pulsed Power Conference, 2007 16th IEEE International; 07/2007
