Reliability of DC-link capacitor in pulsed power supply for accelerator magnet

作     者：Jie Wang Da-Qing Gao Wan-Zeng Shen Hong-Bin Yan Li-Jun Mao 

作者机构：Institute of Modern PhysicsChinese Academy of Sciences School of Nuclear Science and TechnologyLanzhou University School of Nuclear Science and TechnologyUniversity of Chinese Academy of Sciences 

出 版 物：《Nuclear Science and Techniques》 (核技术(英文版))

年 卷 期：2024年第09期

页      面：70-82页

核心收录：

学科分类：080801[工学-电机与电器] 0808[工学-电气工程] 08[工学] 082701[工学-核能科学与工程] 0827[工学-核科学与技术] 

基　　金：supported by the National Key Research and Development Program of China (No. 2019YFA0405402) 

摘      要：Capacitors are widely used in pulsed magnet power supplies to reduce ripple voltage, store energy, and decrease power variation. In this study, DC-link capacitors in pulsed power supplies were investigated. By deriving an analytical method for the capacitor current on the H-bridge topology side, the root-mean-square value of the capacitor current was calculated, which helps in selecting the DC-link capacitors. The proposed method solves this problem quickly and with high accuracy. The current reconstruction of the DC-link capacitor is proposed to avoid structural damage in the capacitor’s current measurement, and the capacitor’s hotspot temperature and temperature rise are calculated using the FFT transform. The test results showed that the error between the calculated and measured temperature increases was within 1.5℃. Finally, the lifetime of DC-link capacitors was predicted based on Monte Carlo analysis. The proposed method can evaluate the reliability of DC-link capacitors in a non-isolated switching pulsed power supply for accelerators and is also applicable to film capacitors.