摘要
电声脉冲法受接触式压电传感器的工作温度限制,难以实现极端环境温度下聚合物介质内的空间电荷检测,因此有必要探究新的检测方法和技术。该文基于电声脉冲法的电-声转换原理,采用非接触式的激光多普勒测振法代替接触式压电检测,并开展正弦激励下基于激光测振的聚合物电荷积累量评估研究。通过对各物理量间关系的理论推导,提出基于电荷-声波-振动信号转换的理论模型。根据激光多普勒测振仪关键性能参数,搭建正弦激励下基于激光测振的空间电荷试验平台,并对激光多普勒测振仪输出端进行灵敏度实验,确定速度端口作为系统的测量端口。通过接触式压电传感器和激光测振的比对检测,分析直流场下电极表面的声波和振动特性,验证所提声波-振动理论模型的准确性。最后,以聚酰亚胺为检测对象,测量直流场下的空间电荷和电极表面振动,发现平均体电荷密度特征量和速度幅值与极化电场呈近似线性关系,去除界面极化电荷的界面平均体电荷密度特征量和去除界面极化电荷作用的速度幅值,均随极化电场变化呈现三段式分布。这表明非接触式激光测振和传统压电传感器检测具有很好的一致性,均可应用于聚合物空间电荷的评估。
It is difficult for pulsed electro-acoustic(PEA)method to detect space charge in polymer media at extreme ambient temperature due to its limitation of working temperature of contact piezoelectric materials.Therefore,it is necessary to explore new detection methods and technologies.Based on the electroacoustic conversion principle of PEA method,this paper adopts non-contact laser Doppler vibration measurement instead of contact piezoelectric detection method to conduct research on the evaluation of polymer charge accumulation based on laser vibration measurement under sinusoidal excitation.A theoretical model based on charge-acoustic-vibration signal conversion is proposed through theoretical derivation of the relationship between various physical quantities.According to the key performance parameters of laser Doppler vibrometer(LDV),a space charge experiment platform based on laser vibration measurement under sinusoidal excitation is built,and the LDV output sensitivity experiment is conducted.The velocity port is determined as the LDV measurement port.By comparing the detection of contact piezoelectric sensors and laser vibration measurement,the acoustic and vibration characteristics of the electrode surface under DC field are analyzed,and the accuracy of the proposed acoustic-vibration theoretical model is verified.Finally,the space charge and electrode surface vibration under DC field are measured with polyimide as the detection object.PEA space charge test and LDV lower electrode vibration test are both conducted for polyimide.It is found that the characteristic quantity of average bulk charge density and velocity amplitude are both appro-ximately linear with polarized electric field,and the characteristic quantity of interfacial average bulk charge density after removing interface polarized charge and velocity amplitude after removing interface polarized charge both present a three-segment distribution with the change of polarized electric field,which indicates that non-contact laser vibration measurement an
作者
孙国强
沈鑫
吴建东
尹毅
SUN Guoqiang;SHEN Xin;WU Jiandong;YIN Yi(Department of Electrical Engineering,Shanghai Jiao Tong University,Minhang District,Shanghai 200240,China)
出处
《中国电机工程学报》
EI
CSCD
北大核心
2024年第11期4556-4565,I0033,共11页
Proceedings of the CSEE
基金
国家自然科学基金项目(52022059)。
关键词
聚合物
空间电荷
激光测振
振动信号
体电荷密度
polymer
space charge
laser vibration measurement
vibration signal
bulk charge density
