【作者】 谢颜斌；

【导师】 唐炬；

【作者基本信息】 重庆大学 ， 电气工程， 2010， 博士

【摘要】 由于气体绝缘组合电器(Gas Insulated Switchgear,简称GIS)内部产生局部放电(Partial Discharge,简称PD)是引发事故的重要因素之一,因此,为了保证GIS的安全可靠运行,国内外对GIS PD在线监测技术开展了大量的研究,但到目前为止,PD信号数学模型和超高频(Ultra High Frequency,简称UHF)信号与其放电量关联分析等问题还是一个尚待深入研究的前沿课题。为此,本文在分析国内外GIS PD检测、数学模型构建和放电量标定研究状况的基础上,结合UHF PD源信号等效测试实验方法,建立了典型缺陷产生PD源信号的组合高斯数学模型,通过研究UHF PD信号各种参量与其放电量之间的内在关联,构建了通过UHF PD信号特征确定其放电量大小的理论与方法,同时,研究了UHF PD信号检测中复小波去噪的复阈值算法。具体工作如下:①在深入研究灵敏度测试实验方法的基础上,通过改进其实验步骤,以高斯函数为标准注入波形,结合多参数调节,并以检测信号的一致性为判定PD源信号精度的条件,建立实验获取UHF PD源信号波形的等效测试法。同时,根据GIS设备绝缘缺陷放电的形式和特点,对设计的四种GIS绝缘缺陷物理模型进行了大量的等效源信号测试实验,获得了真实可靠的源信号波形样本,并研究了各种模拟缺陷在不同实验条件下的PD源信号波形特征,对其做了深入研究和系统分析;②通过分析等效源信号测试实验结果,构建了四种缺陷产生PD源信号的组合高斯数学模型,归纳统一了数学模型的基本形式,只要调节该数学模型中的参数值,便可得到与四种典型缺陷下产生的PD源信号波形相吻合的数学解析式,并且每个参数都具有实际的物理意义,同时通过波形和频谱误差分析,定量计算了模型误差,对该模型的正确性进行了充分论证;③将PD等效源信号数学模型应用于PD源信号多脉冲分离、GIS内电磁波传播特性、信号去噪等领域的研究中,进一步检验了模型的正确性与科学性;同时提出了独立处理实部与虚部的复阈值算法,创新了复小波变换的复阈值理论,解决了不同噪声下对不同UHF PD信号去噪效果的最优化问题;④针对GIS内四种典型绝缘缺陷,结合天线理论,电磁场理论和IEC60270测试方法,通过理论推导证明了UHF信号参量与其放电量之间的内在联系,同时,通过UHF法和IEC60270方法同时采集信号,由实验结果进一步验证理论的正确性,最终构建确定四种典型缺陷UHF PD信号放电量大小的理论与方法。通过完成上述研究内容,最终建立了UHF PD源信号数学模型和根据UHF PD信号特征确定其放电量的新理论与方法。本文旨在通过对UHF PD数学模型与放电量的研究,能够为UHF法理论研究和基于UHF法的在线监测设备的研制奠定理论基础,解决在该领域尚未完全解决的数学模型与UHF PD信号与放电量关联的难题奠定基础。更多还原

【Abstract】 Partial discharge (PD) in Gas Insulated Switchgear (GIS) is one of the important factors for the fault, and therefore the on-line monitoring PD in GIS has been being researched at home and abroad in order to guarantee the safe operation of GIS. At the same time, mathematical model and calibration of the discharge quantity of Ultra High Frequency (UHF) signals are still an advanced problem to be studied. Therefore, on the basis of analysis of the researches about PD detection in GIS, establishment of mathematical model and calibration of the discharge quantity of UHF PD signals, combined with experiments of equivalent source, a Gaussian mathematical model of typical insulation defects are established. The inner relationship between UHF PD signal and its discharge quantity is studied deeply, a theory and method for calibration of discharge quantity is proposed in this paper in order to calibrate discharge quantity by the UHF PD waveform. At the same time, the complex threshold algorithm of complex wavelet transform is studied and used in de-noising of UHF PD signals. The main achievements are as follows.①Based on technique of the sensitivity test, by improving the experimental procedure, combining with multiply parameters adjustment, experiments of equivalent source is established which could acquire PD waveform of PD source directly. At the same time, according to the features of PD of insulation defects in GIS, four types of insulation defects of GIS are devised and a lot of PD data are acquired by various PD experiments of equivalent source. Meanwhile, the waveform features of different types of insulation defects under different experimental conditions are studied deeply.②Gaussian mathematical model is established for all types of PD of simulation insulation defects by analysis of data from experiments of equivalent source. Gaussian mathematical model have identical expression for four types of PD of simulation insulation defects and every parameter in this model has physical meaning. The mathematical models are verified by waveform error analysis and spectrum error analysis.③Gaussian mathematical models of typical defects are used in source separation of multi-signals, study of propagation features of UHF signal in GIS, de-noising of PD signals and so on. These applications verify the correctness of these Gaussian mathematical models. At the same time, algorithm of complex threshold of complex wavelet transform is proposed in this paper, which could de-noise PD signals in different noise level.④Combined with antenna theory, electromagnetic field theory and IEC60270, relationship between UHF signal and its discharge quantity is studied. And then, UHF signals and signals from method of IEC 60270 are acquired for four types of PD of simulation insulation defects at the same time. The relationship between UHF PD signal and its discharge quantity is studied deeply and a theory and method for calibration of discharge quantity by waveform of UHF PD is established.A new theory and method of mathematical model and calibration of discharge quantity by waveform of UHF PD are established by completing studies above. The purposes of these studies is to lay a foundation of studies of UHF monitoring and the developing of the UHF PD online monitoring system and solve the problems of mathematical model and calibration of discharge quantity.更多还原