摘要
采用电声脉冲法测量绝缘内部空间电荷分布时,应用仿真方法准确评估测量系统的特性有助于电荷结果的精确分析。针对测量过程中声波传播与转化这一电荷信号关键传递过程,结合传输线模型中的电压波传播原理,提出了声波信号的等效有损传输线模型的构建方法。基于电极记录点和传感器位置处的一致模拟结果与分析结果,验证了仿真模型的可靠性。针对实际测量过程中存在的反射杂波信号问题,指出脉冲激励频率过高时反射杂波可能会影响实际测量的有效信号。进一步仿真结果表明,半导电电极与试样声阻抗不匹配会影响上电极界面的声波幅值,而背衬吸声材料与传感器不匹配则会影响获得的测量波形形状。最后针对多层介质的模拟结果发现,测量所选背衬吸声材料的厚度也需远大于多层试样的厚度,以避免反射对有效测量信号的叠加影响。由此,仿真模型可以有效评估实际电声脉冲测量系统的声学特性。
When using the pulsed electro-acoustic(PEA) method to measure space charge inside insulation materials, a characteristic evaluation of measurement system based on simulation methods is beneficial to the accurate analysis of charge results. For the acoustic propagation and transition in the measurement process representing charge signal propagation process, the modeling method of the equivalent lossy transmission line model of acoustic waves was proposed combining with the propagation principle of voltage wave in transmission lines. Based on the consistent simulation results and theoretical analysis on the electrode record point and transducer, the reliability of the model was verified. For the actual situation of reflected clutter signals existing in the measurement results, it is pointed out that the clutter signals may affect the measured effective signals when the frequency of pulse excitation is excessively high. Further simulation results indicate that the mismatch of acoustic impedances between semiconducting electrode and sample can affect the measured acoustic amplitude on the interface of upper electrode. Moreover, the mismatch of sound-absorbing material and transducer can influence the shape of waveforms. Finally, the simulation results of multi-layer sample show that the thickness of the sound-absorbing material should be much larger than that of the multi-layer sample to avoid the superposition effect of reflection. And the acoustic characteristic of an actual PEA measurement system can be effectively evaluated by the simulation model.
作者
任瀚文
李庆民
李承前
高浩予
刘涛
REN Hanwen;LI Qingmin;LI Chengqian;GAO Haoyu;LIU Tao(State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources,North China Electric Power University,Beijing 102206,China;China Electric Power Research Institute,Beijing 100192,China)
出处
《高电压技术》
EI
CAS
CSCD
北大核心
2021年第4期1485-1494,共10页
High Voltage Engineering
基金
国家自然科学基金(51929701
51737005)
北京市自然科学基金(3202031)
中央高校基本科研业务费专项资金(2019QN113)
国家留学基金。
关键词
电声脉冲法
传输线模型
声学特性
反射信号
声阻抗
pulsed electro-acoustic method
transmission line model
acoustic characteristic
reflected signal
acoustic impedance
作者简介
任瀚文,1994-,男,博士生,主要从事固体绝缘材料中空间电荷测试方面的研究工作,E-mail:rhw112118@163.com;通信作者:李庆民,1968-,男,博士,教授,博导,主要从事高电压绝缘技术、放电物理等方面的研究工作,E-mail:lqmeee@ncepu.edu.cn。
