高压高频变压器寄生电容实验提取方法  

An Experimental Method for Extracting Parasitic Capacitances of High-voltage High-frequency Transformers

作　　者：刘晨[1] 齐磊[1] 崔翔[1] 赵国亮 

机构地区：[1]华北电力大学新能源电力系统国家重点实验室,北京102206 [2]全球能源互联网研究院,北京100192

出　　处：《华北电力大学学报（自然科学版）》2017年第1期1-8,共8页Journal of North China Electric Power University：Natural Science Edition

基　　金：国家自然科学基金资助项目(51277065)

摘　　要：高压高频变压器是大容量DC-DC变换器实现电气隔离和电压变换的关键装备。随着容量和电压等级的提高,高性能金属磁芯和油纸绝缘系统将应用于高压高频变压器以提高功率密度。高压大容量工况下金属磁芯和油箱均需接地以避免悬浮电位产生的局部放电,使得高压高频变压器绕组对地电容效应亟待研究。为了能够在不清楚变压器内部信息的情况下对寄生电容进行分析,提出了一种高压高频变压器寄生电容的实验提取方法。基于变压器的Y参数矩阵,利用直接测量和间接测量获得了一系列不同绕组端子条件下的电容约束方程。通过方程独立性分析,实现了高压高频变压器包括绕组对地电容在内共10个电容参数的有效提取。通过一台20 k Hz高压高频变压器原型机验证了所提方法的有效性。在此基础上分析了不同绕组接地情况下高压高频变压器的电压传输特性,结果表明绕组对地电容会显著影响电压传输特性的谐振频率以及工作频率下的实际电压变比。The high-voltage high-frequency transformer is the key equipment for the galvanic isolation and voltage transformation of high-capacity DC-DC converter. With the improvement of capacity and voltage level,high-performance metallic core and oil-paper insulation system may be used in order to enhance power density of the high-voltage high-frequency transformer. At high-voltage and high-capacity working condition,metallic core and oil tank have to be grounded in order to avoid partial discharge caused by floating potentials,which makes winding-to-earth capacitance effect of high-voltage high-frequency transformer urgent to be investigated. In order to analyze parasitic capacitance without knowing internal information of the transformer,an experimental method for extracting parasitic capacitance of high-voltage high-frequency transformer is proposed in this paper. Based on Y parameter matrix of the transformer,capacitance constraint equations under different winding conditions are deduced by direct and indirect measurements. By analyzing the independence of the equations,ten capacitance parameters of high-voltage high-frequency transformer including winding-to-earth capacitance can be effectively extracted. A 20 k Hz high-voltage high-frequency transformer prototype is used to verify the effectiveness of the proposed method. Besides,voltage transfer characteristics of highvoltage high-frequency transformer under different winding grounding conditions are analyzed,and the results indicate that winding-to-earth capacitance will significantly impact resonant frequency of voltage transfer characteristic and voltage ratio at operating frequency.

关 键 词：高频变压器 寄生电容 参数提取 传输特性 

分 类 号：TM42[电气工程—电器]