金属化膜电容元件宽频特性研究  

Study on Broadband Characterization of Metallized Film Capacitor Element

作　　者：易承乾 李超然 张波[1] 贾华 盖斌 黄葵 邓光昭 吴云翼 李婉 YI Chengqian;LI Chaoran;ZHANG Bo;JIA Hua;GAI Bin;HUANG Kui;DENG Guangzhao;WU Yunyi;LI Wan(Department of Electrical Engineering,Tsinghua University,Beijing 100084,China;Xi’an High Voltage Apparatus Research Institute Co.,Ltd.,Xi’an 710077,China;Jiashan Sun King Power Electronic Capacitor Co.,Ltd.,Zehjiang Jiashan 314100,China;CTG Science and Technology Research Institute,Beijing 101199,China)

机构地区：[1]清华大学电机工程与应用电子技术系,北京100084 [2]西安高压电器研究院股份有限公司,西安710077 [3]嘉善赛晶电容有限公司,浙江嘉善314100 [4]中国长江三峡集团有限公司科学技术研究院,北京101199

出　　处：《电力电容器与无功补偿》2024年第1期164-168,共5页Power Capacitor & Reactive Power Compensation

基　　金：国家重点研发计划(2021YFB2401505)。

摘　　要：金属化膜电容器被广泛使用在换流阀等电工装备中,在电力电子开关快速动作的影响下,电容器将承受高频冲击,因此有必要研究宽频范围内电容器的特性。本文以单个电容元件为研究对象,使用数字电桥对20 Hz~2 MHz范围内电容元件的阻抗特性进行了测量,通过数据拟合和实验测量结合的方式建立了等效电路模型,并对不同频率下的阻抗特性和等效电路参数进行了分析。研究结果表明:在低频(<150 kHz)下,参数恒定的等效电路模型可准确地描述电容元件的阻抗特性和内部物理过程;而在高频(>150 kHz)下,电容元件内部不同区域的电流分布将发生变化,导致电容元件的等效电感和等效电阻等参数发生频变,引起阻抗特性发生变化。本文结果可对分析高频冲击下电容器劣化机理提供指导。Metallized film capacitor is widely used in such electrical equipment as converter valves and,under the influence of rapid operation of power electronic switches,will be subjected to high-frequency shocks,it is therefore necessary to study the characteristics of the capacitor in a wide frequency range.In this paper,the single capacitor elements is taken as the study object.The impedance characteristics of capacitor elements in the range of 20 Hz~2 MHz are measured by using a digital bridge.An equivalent circuit model is set up by a combination of data fitting and experimental measurements and the impedance characteristics and equivalent circuit parameters at different frequencies are analyzed.The study results show that at low frequencies(<150 kHz),the equivalent circuit model with constant parameters can accurately describe the impedance characteristics and internal physical processes of the capacitor element,while at high frequencies(>150 kHz),the current distribution in different areas inside the capacitor element will change,resulting in a frequency change of such parameters as equivalent inductance and equivalent resistance of the element,which causes a change in the impedance characteristics.The results of this paper can provide guidance for analyzing the degradation mechanism of capacitor under high-frequency shocks.

关 键 词：金属化膜电容器 宽频特性 等效电路 频变参数 

分 类 号：TM53[电气工程—电器] TM721.1