变电站局放监测的电磁干扰特征及标准化测试研究

发布时间：2019-02-11 21:49

【摘要】：变电站复杂的电磁干扰环境是造成当前局部放电在线检测技术出现误报漏报的重要原因,也是长期以来困扰局放在线检测技术发展应用的关键瓶颈。本文在分析了国内外局放检测抗干扰技术的基础上,系统研究了变电站内影响局部放电检测的电磁干扰信号的特征、来源及影响因素,提出了干扰模拟和分级的方法,建立了针对局部放电检测设备抗电磁干扰性能检验和评价的标准化测试方案。主要内容如下:选取了代表性的变电站和测试点,采用UHF和高频电流检测手段通过现场实测的方式研究了典型电磁干扰信号的特征以及来源,并采用TEV法对开关柜作了相应测试。研究发现:移动通讯和变电站设备外部的放电是局放UHF检测最主要的电磁干扰形式,原始信号幅值最大至200mV以上,频带均在UHF检测内;高频检测干扰信号的幅值在5.8~501mV范围内,频谱一般分布在90MHz以下;50%以上变电站的开关柜存在脉冲信号。通过数据关联分析的方法,研究了电磁干扰信号的动态变化与气象条件(温度、湿度)、负荷状况之间的关联关系,采用对比的方式研究了地理位置、电压等级对电磁干扰动态变化的影响。结果表明,变电站电磁干扰信号受温度因素影响最大,尤其是放电类干扰,特征关联度均值在0.9以上,湿度次之,负荷最小;地理位置和电压等级会间接影响电磁干扰信号的类型、幅值以及信号发生的概率。借鉴EMC标准分级方法,结合局放监测装置的工作特点和易受影响的程度,根据电磁干扰信号的来源、类型、强度、发生频度等指标,提出了典型电磁干扰模拟和分级的方法以及局放监测装置标准化的干扰测试平台搭建的方案,并给出了相应的评价指标。
[Abstract]:The complex electromagnetic interference (EMI) environment in substations is an important reason for the misinformation and underreporting of the current PD on-line detection technology, and it is also the key bottleneck of the development and application of the on-line detection technology for a long time. Based on the analysis of anti-jamming technology of PD detection at home and abroad, this paper systematically studies the characteristics, sources and influencing factors of electromagnetic interference signals affecting PD detection in substations, and puts forward the methods of jamming simulation and classification. A standardized test scheme for testing and evaluating the performance of PD detection equipment against electromagnetic interference is established. The main contents are as follows: the typical substation and test points are selected, and the characteristics and sources of typical electromagnetic interference signals are studied by means of UHF and high frequency current detection. The TEV method is used to test the switchgear. It is found that the external discharge of mobile communication and substation equipment is the most important form of electromagnetic interference in PD UHF detection. The original signal amplitude is larger than 200mV and the frequency band is within UHF detection. The amplitude of the high frequency detection interference signal is in the range of 5.8~501mV, the frequency spectrum is generally distributed below 90MHz, and the pulse signal exists in the switchgear of more than 50% substation. By means of data correlation analysis, the relationship between the dynamic change of EMI signal and meteorological conditions (temperature, humidity) and load condition is studied. The influence of voltage level on the dynamic change of electromagnetic interference. The results show that the electromagnetic interference signal of substation is most affected by temperature factors, especially the discharge type interference, the average of characteristic correlation degree is more than 0.9, the humidity is the second, and the load is the least. Geographical location and voltage level indirectly affect the type, amplitude and probability of EMI signal. Based on the standard classification method of EMC, combined with the working characteristics and vulnerable degree of PD monitoring device, according to the source, type, intensity and frequency of electromagnetic interference signal, The methods of simulation and classification of typical electromagnetic interference and the scheme of setting up a standardized interference test platform for PD monitoring device are put forward, and the corresponding evaluation indexes are given.
【学位授予单位】：华北电力大学(北京)
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM63;TM855

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