油纸绝缘介质损耗与局部放电关联特性研究

发布时间：2018-10-24 20:23

【摘要】：介质损耗及局部放电是衡量油纸绝缘绝缘性能的重要指标,研究油纸绝缘介损与局放关联特性对提高基于介损及局放的油纸绝缘状态监测及诊断水平,实现基于多元信息融合的油纸绝缘状态评估,具有重要意义。本文搭建了油纸绝缘介损、局放测量实验平台,实现了介损值及局放统计参量精确计算,分析了局放发展过程中介损值、介损值增量及局放统计参量变化特性,研究了油纸绝缘介损值、介损值增量与局放统计参量的关联特性。设计了油纸绝缘沿面放电缺陷模型,得到了绝缘纸板含水率不同的油纸绝缘试品;搭建了油纸绝缘介损及局放测量实验平台,满足了介损测量用信号及局放信号采集需求;提出了一种基于迭代匹配追踪的介损角计算方法,仿真结果表明,该方法可实现介损值精确、稳定计算。基于升压法实验,得到各试品介损及局放统计参量变化规律。结果表明:对于局部放电,随着电压升高,总放电量、最大放电量、平均放电量逐渐增大;总放电次数、平均放电脉冲长度先增大后振荡下降;各谱图偏斜度,Hn(q)谱图峭度、Weibull分布?系数规律性较强;绝缘纸板含水率对总放电量、最大放电量、平均放电量、?系数影响较大,同一电压,绝缘纸板含水率越高,上述参量数值越大、增长越快。对于介损,随着电压升高,各试品介损值增量先升高后稳定或后下降、各试品介损值逐渐增大,但电压较高时介损值上升速率明显放慢,且有饱和趋势,绝缘纸板含水试品介损值甚至出现下降趋势。构建了含局部缺陷的绝缘介质介损变化数学模型,解释了局放影响下各试品介损值变化规律。分析了介损值与局放统计参量的关联关系,研究了介损值增量与局放50Hz基波分量的关联特性。结果表明,随着局放发展,介损值变化规律受局部缺陷处介损值增大及局部缺陷范围扩大影响;介损值与局放总放电量,总放电次数,平均放电量,最大放电量,平均放电脉冲长度,Hn(q)谱图偏斜度、陡峭度及Weibull分布?系数关联性较强,但并非单调线性相关,且受绝缘纸板含水率影响,难以建立介损值与单一局放统计参量间简单关联关系。局放信号50Hz基波分量对介损值增量有重要影响,两者基本单调相关,且局放50Hz基波分量受平均放电量、总放电次数及放电脉冲持续时间影响,在上述统计参量共同作用下,各试品介损值增量呈特定变化规律。
[Abstract]:Dielectric loss and partial discharge are important indexes to measure the insulation performance of oil-paper. The correlation between dielectric loss and partial discharge of oil-paper insulation is studied to improve the monitoring and diagnosis level of oil-paper insulation based on dielectric loss and partial discharge. It is of great significance to realize the evaluation of oil-paper insulation based on multiple information fusion. In this paper, an experimental platform for oil paper insulation dielectric loss and partial discharge measurement is set up. The accurate calculation of dielectric loss and partial discharge statistical parameters is realized. The variation characteristics of intermediate loss value, dielectric loss increment and partial discharge statistical parameters during partial discharge development are analyzed. The correlation characteristics of dielectric loss value, dielectric loss increment and partial discharge statistical parameters of oil-paper insulation are studied. The defect model of oil-paper insulation along the surface discharge is designed, and the oil-paper insulation test material with different moisture content is obtained, and the experimental platform of oil-paper insulation dielectric loss and partial discharge measurement is built to meet the needs of signal acquisition for dielectric loss measurement and partial discharge signal. A method for calculating dielectric loss angle based on iterative matching tracing is proposed. The simulation results show that the method can calculate the dielectric loss accurately and stably. Based on the booster test, the variation of dielectric loss and partial discharge statistical parameters of each sample is obtained. The results show that for partial discharge, the total discharge, the maximum discharge and the average discharge increase with the increase of voltage, and the total discharge times and the average discharge pulse length increase first, and then the oscillation decreases. , Hn (q) spectral kurtosis, Weibull distribution? The coefficient is regular, the moisture content of insulating paperboard has great effect on the total discharge, maximum discharge, average discharge,? The same voltage, the higher the moisture content of insulating paperboard, the greater the value of the above parameters and the faster the growth. For dielectric loss, with the increase of voltage, the increment of dielectric loss increased first and then stabilized or decreased. The dielectric loss value of each sample gradually increased, but the increasing rate of dielectric loss value slowed down obviously when the voltage was higher, and had the tendency of saturation. The dielectric loss value of the water-containing test material of insulating paperboard even showed a downward trend. A mathematical model of dielectric loss change in insulating medium with local defects is established, and the variation law of dielectric loss value of each sample under the influence of partial discharge is explained. The correlation between dielectric loss and PD statistical parameters is analyzed, and the correlation characteristics between the increment of dielectric loss and the fundamental component of PD 50Hz are studied. The results show that with the development of PD, the variation of dielectric loss is affected by the increase of dielectric loss and the expansion of local defect, the dielectric loss and the total discharge quantity, the total discharge number, the average discharge quantity, the maximum discharge quantity, the total discharge number, the average discharge quantity and the maximum discharge quantity of partial defect. Average discharge pulse length, Hn (q) spectrum deflection, steepness and Weibull distribution? The correlation of coefficient is strong, but it is not monotone linear correlation, and affected by moisture content of insulating paperboard, it is difficult to establish a simple correlation relationship between dielectric loss value and single partial discharge statistical parameter. The fundamental component of PD signal 50Hz has an important effect on the increment of dielectric loss, and the fundamental component of PD 50Hz is affected by the average discharge quantity, the total discharge number and the duration of the discharge pulse. The increment of dielectric loss value of each sample showed a specific variation rule.
【学位授予单位】：华北电力大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM855

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