环氧树脂高频松弛的交流电导与双极性方波击穿特性

doi:10.19595/j.cnki.1000-6753.tces.222129

摘要
图/表
参考文献
相关文章 (15)

全文: PDF (768 KB)
输出: BibTeX | EndNote (RIS)

摘要

高频非正弦电压下环氧树脂击穿表现出较强的频率依赖性,并且存在复杂的宽频电-热耦合特性。高频电压下环氧树脂交流电导,特别是载流子非线性输运过程是理解高频绝缘击穿的关键。本文以两种电工环氧树脂为研究对象,采用宽频介电谱研究了环氧试样交流电导的频率与温度依赖关系,通过Almond-West模型分析得到低频下交流类直流电导率与温度的关系,低频电导随温度变化更符合Vogel-Fulcher-Tammann 模型。基于Havriliak-Negami复合介质多分散松弛极化理论,分析了高频、高温下的松弛行为,认为高频交流电导率主要由松弛过程α产生的极化损耗引起。通过高频双极性方波击穿测试平台,测试了重复频率双极性方波电压(500Hz, 1kHz, 2kHz, 3kHz)下环氧试样的击穿场强,基于三参数Weibull分布统计分析了特征击穿场强随频率的关系,发现击穿场强与频率呈负相关。研究提出了考虑Poole-Frenkel效应的高频高场交流电导模型,并建立了高频自由体积随频率变化的击穿模型。研究指出高频下分子链段振动效应增强,导致交流电导增强;高频下分子链运动滞后于频率响应,导致总体自由体积增大,造成高频击穿场强下降。研究结果对高频绝缘破坏与可靠性研究具有重要意义。

	服务

	把本文推荐给朋友
	加入我的书架
	加入引用管理器
	E-mail Alert
	RSS
	作者相关文章
	蒋起航
	王威望
	钟禹
	李盛涛
	徐永生

关键词 ：环氧树脂, 交流电导, 双极性方波, 自由体积, 高频击穿特性

Abstract：

As one of the solid insulation materials of high frequency transformer (HFT), epoxy resin presents good performance under high frequency non-sinusoidal electrical voltage. Its insulation performance depends strongly on voltage frequency. Due to the local temperature rise in high frequency transformer, electrothermal effect can increase the conductivity of epoxy resin. Nevertheless, the AC conductivity from the dielectric spectrum measurement cannot be equivalent to the AC conductivity characteristics under high-frequency non-sinusoidal voltage. Therefore, this paper studies the AC conductivity characteristics under high-frequency square voltage by the Fourier decomposition. By improving the free volume breakdown theory, the mechanism underlying the AC conductivity of epoxy resin on breakdown at high frequency is discussed. The relationship between the AC conductivity and the high frequency breakdown of epoxy resin is analyzed by the high frequency relaxation characteristics and high frequency and high field conduction theory.
Two kinds of epoxy resin samples E1 and E2 were prepared using the same preparation process and method. According to the results of glass transition temperature T_g and AC conductivity, the Almond-West (A-W) model and Havriliak-Negami (H-N) multi-dispersion relaxation polarization model were used to fit and analyze the AC conductivity spectrum at different temperatures, and the DC conductivity of epoxy resin at different temperatures was also obtained. Then, the temperature and frequency dependence of relaxation process α and relaxation process δ are analyzed according to the fitting results of H-N model. According to the insulation breakdown measurement results, the breakdown characteristics of two epoxy samples within 500-3000Hz were analyzed. Based on the statistical results of three-parameter Weibull distribution, the relationship between the featured breakdown field strength and the frequency was obtained. According to Jonscher's universal dielectric response model, Poole-Frenkel effect, DC conductivity, the effects of frequency and electric field on AC conductivity under bipolar square wave voltage are analyzed. The free volume breakdown model under high frequency electric field is proposed to analyze the influence of frequency on the AC conductivity and high frequency breakdown in the epoxy resin samples.
According to the fitting results of the A-W model and the H-N model, the AC conductivity is mainly determined by the polarization loss caused by the relaxation process α above T_g. The relaxation process α depends on the dipole turning polarization, and the dipole concentration in the epoxy resin sample with high epoxy value is higher. The relaxation process δ is determined by the DC conductivity process, and δ process is related to the carrier migration across the barrier. The breakdown strengths of two epoxy resin samples decrease with the increase in frequency. The breakdown strength of E1 sample is greater than that of E2.
According to the measured results, fitting results and model analysis, we can obtain the conclusions. (1) The AC conductivity at high frequency and high field includes dipole conductivity at low field, Poole-Frenkel emission of charge carriers under high frequency electric field and the DC conductivity. The AC conductivity increases with the increase in frequency or electric field. (2) The hysteresis effect of movements of molecular chain segments under high-frequency electric field become obviously as the frequency increases. The maximum length of the unoccupied equivalent free volume between the molecular chains increases, resulting in the reduction of breakdown strength at high frequency voltage. In addition, the molecular group spacing decreases with the increase in frequency, leading to the decrease of carrier hopping potential barrier and the increase in AC conductivity of epoxy resin samples.

Key words： Epoxy resin AC conductivity bipolar square wave voltage free volume high frequency breakdown

收稿日期: 2022-11-11

PACS:

TM215.1

基金资助:

国家自然科学基金面上资助项目（52177025）、陕西省自然科学基础研究计划青年项目（2020JQ-045）和电力设备电气绝缘国家重点实验室中青年基础研究创新基金项目（EIPE21314）资助

通讯作者: 王威望男,1987年生,博士,副教授,研究方向为绝缘介质理论与应用,高频磁件设计与绝缘可靠性。E-mail：weiwwang@xjtu.edu.cn

作者简介: 蒋起航男,1998年生,硕士,研究方向为聚合物介电与击穿性能。E-mail：jqhang@stu.xjtu.edu.cn

引用本文:

蒋起航, 王威望, 钟禹, 李盛涛, 徐永生. 环氧树脂高频松弛的交流电导与双极性方波击穿特性[J]. 电工技术学报, 0, (): 124-124. Jiang Qihang, Wang Weiwang, Zhong Yu, Li Shengtao, Xu Yongsheng. AC Conductivity with High Frequency Relaxation and Breakdown Characteristics of Epoxy Resin Under Bipolar Square Wave Voltage. Transactions of China Electrotechnical Society, 0, (): 124-124.

链接本文:

https://dgjsxb.ces-transaction.com/CN/10.19595/j.cnki.1000-6753.tces.222129 https://dgjsxb.ces-transaction.com/CN/Y0/V/I/124

[1] 陈平, 王德中. 环氧树脂及其应用[M]. 化学工业出版社, 2004: 1, 23.
[2] 刘贺晨, 郭展鹏, 李岩, 等. 衣康酸基环氧树脂和双酚A环氧树脂性能对比研究[J]. 电工技术学报, 2022, 37(09): 2366-2376.
Liu Hechen, Guo Zhanpeng, Li Yan, et al.Comparative study on properties of itaconic acid based epoxy resin and bisphenol A epoxy resin[J]. Transactions of China Electrotechnical Society, 2022,37(09): 2366-2376.
[3] Pragyan Mohan.A Critical Review: The Modification, Properties, and Applications of Epoxy Resins[J]. POLYMER-PLASTICS TECHNOLOGY AND ENGINEERING, 2013, 52(2): 107-125.
[4] 王威望, 刘莹, 何杰峰, 等. 高压大容量电力电子变压器中高频变压器研究现状和发展趋势[J]. 高电压技术, 2020, 46(10): 3362-3373.
Wang Weiwang, Liu Ying, He Jiefeng, et al.Research status and development trend of medium and high frequency transformers for high-voltage and large capacity power electronic transformers[J]. High Voltage Engineering, 2020,46(10): 3362-3373.
[5] Wang W, He J, Liu Y, et al.Effects of Spike Voltages coupling with high dV/dt Square wave on Dielectric Loss and Electric-thermal field of High-Frequency Transformer. IEEE Access, 2021, 9: 137733-137743.
[6] 汪涛, 骆仁松, 文继峰, 等. 基于辅助绕组的高频变压器绕组损耗测量方法[J]. 电工技术学报, 2022, 37(10): 2622-2630+2655.
Wang Tao, Luo Rensong, Wen Jifeng, et al. Winding loss measurement method of high-frequency transformer based on auxiliary winding[J] Transactions of China Electrotechnical Society, 2022, 37 (10): 2622-2630+2655.
[7] Wang W, Liu Y, He J, et al.An Improved Design Procedure for A 10 kHz, 10 kW Medium-Frequency Transformer Considering Insulation Breakdown Strength and Structure Optimization[J]. IEEE Journal of Emerging and Selected Topics in Power Electronics, vol. 10, no. 4, pp. 3525-3540, Aug. 2022.
[8] 惠苏新, 王鹏, 吴琦, 等. 重复脉冲占空比对环氧树脂电树生长特性影响研究[J]. 中国电机工程学报, 2020, 40(16): 5383-5392.
Hui Suxin, Wang Peng, Wu Qi, et al.Study on the influence of repetitive pulse duty ratio on the growth characteristics of epoxy resin electrical trees[J]. Proceedings of the CSEE, 2020, 40(16): 5383-5392.
[9] 何东欣, 张涛, 陈晓光, 等. 脉冲电压下电力电子装备绝缘电荷特性研究综述[J]. 电工技术学报, 2021, 36(22): 4795-4808.
He Dongxin, Zhang Tao, Chen Xiaoguang, et al.Summary of research on insulation charge characteristics of power electronic equipment under pulse voltage[J]. Transactions of China Electrotechnical Society, 2021, 36(22): 4795-4808.
[10] 赵波, 张宁, 李琳, 等. 大容量高频变压器磁芯损耗特性分析及结构选择[J]. 磁性材料及器件, 2016, 47(01): 39-43.
Zhao Bo, Zhang Ning, Li Lin, et al.Analysis of core loss characteristics and structure selection of large capacity high-frequency transformer[J]. Journal of Magnetic Materials and Devices, 2016, 47(01): 39-43.
[11] 张宏亮, 张丝钰, 刘鹏, 等. 高温下纳米氧化石墨烯/环氧树脂复合材料的载流子特性[J]. 高电压技术, 2018, 44(12): 3814-3823.
Zhang Hongliang, Zhang Siyu, Liu Peng, et al.Carrier characteristics of nano graphene oxide/epoxy resin composites at high temperatures[J]. High Voltage Engineering, 2018, 44(12): 3814-3823.
[12] 陈向荣, 黄小凡, 王启隆, 等. 温度和频率对环氧树脂/碳化硅晶须复合材料交流非线性特性的影响[J]. 电工技术学报, 2022, 37(15): 3897-3912.
Chen Xiangrong, Huang Xiaofan, Wang Qilong, et al.Effect of temperature and frequency on AC nonlinear characteristics of epoxy resin/silicon carbide whisker composites[J]. Transactions of China Electrotechnical Society, 2022, 37(15): 3897-3912.
[13] Jilani W., Mzabi N., Gallot-Lavallée, O. et al. Study of AC electrical conduction mechanisms in an epoxy polymer[J]. Eur. Phys. J. Plus 130, 235 (2015).
[14] 王威望, 李盛涛. 工程固体电介质绝缘击穿研究现状及发展趋势[J]. 科学通报, 2020, 65(31): 3461-3474.
Wang Weiwang, Li Shengtao.Research Status and Development Trend of Engineering Solid Dielectric Insulation Breakdown[J]. Chinese Science Bulletin, 2020, 65(31): 3461-3474.
[15] M. Ieda, M. Nagao and M. Hikita, High-field conduction and breakdown in insulating polymers. Present situation and future prospects[J]. IEEE Transactions on Dielectrics and Electrical Insulation, vol. 1, no. 5, pp. 934-945, Oct. 1994.
[16] 赵义焜, 张国强, 郭润睿, 等. 高频变压器用耐高温型匝间绝缘材料的击穿特性[J]. 高电压技术, 2020, 46(02): 657-665.
Zhao Yikun, Zhang Guoqiang, Guo Runrui, et al.Breakdown characteristics of high temperature resistant turn to turn insulation materials for high-frequency transformers[J]. High Voltage Engineering, 2020, 46(02): 657-665.
[17] Wang W, Wang X, He J, et al.Dielectric Breakdown Characteristics of Epoxy Resin Induced by High Frequency Electric Stress Used in Solid State Transformer[C]. 2020 IEEE 3rd International Conference on Dielectrics (ICD), 2020: 162-165.
[18] C. Zhanget al. Effect of Bipolar Square Wave Voltage with Varied Frequencies on Electrical Tree Growth in Epoxy Resin[J]. IEEE Transactions on Dielectrics and Electrical Insulation, vol. 28, no. 3, pp. 806-814, June 2021.
[19] 李盛涛, 谢东日, 闵道敏. 聚丙烯/Al₂O₃纳米复合介质直流击穿特性与电荷输运仿真研究[J]. 中国电机工程学报, 2019, 39(20): 6122-6130+6193.
Li Shengtao, Xie Dongri, Min Daomin. Simulation study on DC breakdown characteristics and charge transport of polypropylene/Al2O3 nanocomposites[J]. Proceedings of the CSEE, 2019, 39 (20): 6122-6130+6193.
[20] 谢东日, 刘晔, 黄印, 等. 聚丙烯/BN复合介质高频击穿性能提升与电荷输运仿真研究[J]. 高电压技术, 2020, 46(02): 648-656.
Xie Dongri, Liu Ye, Huang Yin, et al.Simulation Study on High Frequency Breakdown Performance Improvement and Charge Transport of Polypropylene/BN Composite Dielectric[J]. High Voltage Engineering, 2020, 46(02): 648-656.
[21] Dissado L A, Fothergill J C.Electrical degradation and breakdown in polymers[B]. Peter Peregrinus, 1992.
[22] 王威望, 李盛涛, 刘文凤. 聚合物纳米复合电介质的击穿性能[J]. 电工技术学报, 2017, 32(16): 25-36.
Wang Weiwang, Li Shengtao, Liu Wenfeng.Breakdown properties of polymer nanocomposite dielectrics[J]. Transactions of China Electrotechnical Society, 2017, 32(16): 25-36.
[23] Li Mingru, Cai Zhuoli, Niu Huan, et al.The effect of epoxide on molecular chain relaxation on bisphenol a epoxy resin after curing[C]//2021 International Conference on Electrical Materials and Power Equipment, Chongqing, China, 2021, pp. 1-4.
[24] ALMOND D P, DUNCAN G K, WEST A R.The determination of hopping rates and carrier concentrations in ionic conductors by a new analysis of AC conductivity[J]. Solid State Ionics, 1983, 8(2): 159-164.
[25] K. C. Kao, Dielectric phenomena in solids[M]. Elsevier: San Diego, California, pp. 77-97, 2004.
[26] DIAHAM S, LOCATELLI M-L. Concentration and mobility of charge carriers in thin polymers at high temperature determined by electrode polarization modeling[J]. Journal of Applied Physics, 2012, 112(1): 013710-1-6.
[27] Dudowicz J, Freed K F,Douglas J F. The Journal of Physical Chemistry B 2005 109(45), 21285-21292.
[28] DREMER F, SCHONHALS A.Broadband dielectric spectroscopy[M]. Germany: Springer, 2003: 77-117.
[29] Y. Huang, D. Min, S. Li, et al.Dielectric relaxation and carrier transport in epoxy resin and its microcomposite[J]. IEEE Transactions on Dielectrics and Electrical Insulation, vol. 24, no. 5, pp. 3083-3091, Oct. 2017.
[30] USHAKOV V.Impulse breakdown in liquids[M]. New York, USA: Springer, 2007.
[31] A. K. Jonscher.The ‘universal’ dielectric response[J]. Nature 267, 673-679, 1977.
[32] T. Tokoro, K. Tohyama. M.Nagao, et al. High-Field Dielectric Properties of Polyethylene in the High-Temperature Region[J]. Electrical Engineering in Japan. 112(6), 10-19, 1992.
[33] A. K. Jonscher.Energy losses in hopping conduction at high electric fields[J]. Phys. C: Solid State Phys. 4, 1331, 1971.
[34] A. K. Jonscher, C. K. Loh.Poole-Frenkel conduction in high alternating electric fields[J]. Phys. C: Solid State Phys. 4, 1341, 1971.