【作者】 高强；

【导师】 李和明； 律方成；

【作者基本信息】 华北电力大学（河北） ， 高电压与绝缘技术， 2010， 博士

【摘要】 电力系统污闪事故时有发生,所造成的损失是巨大的,监测绝缘子表面污秽情况可有效进行预警并指导线路检修,对于绝缘子污秽检测的研究一直是个热点与难点课题。本文根据微波辐射理论,系统地研究了绝缘子污秽检测技术和方法,完成的主要工作和取得的创新成果如下:1、提出了微波辐射测量绝缘子污秽的方法。从理论上推导了辐射计测量污秽的天线温度计算公式、污秽的辐射亮温反演计算公式,确定了理论计算和技术实施方案。2、提出了污秽的辐射亮温模型。分析研究了模型中的参数对辐射亮温的影响,这些参数包括发射率、污层厚度、绝缘子材质、工作频率、极化方式和测量角度等。研究了污秽物的等值盐密(ESDD)与辐射亮温的关系、复介电常数与ESDD的关系,研究表明污秽物的复介电常数变化是引起污秽辐射亮温变化的内在因素。通过实验进一步验证了ESDD与复介电常数的关系。3、基于拟合技术,建立了辐射亮温与等值盐密/等值灰密(NSDD)的关系。通过回归方程检验了模型的正确性。模型表明辐射亮温与ESDD/NSDD之间满足幂函数关系;用干燥和湿润条件下的测量结果,可求解ESDD和NSDD。实验研究了XP-70绝缘子的人工污秽,研究结果表明施加高电压对天线温度没有直接影响,验证了自然污秽与人工污秽的辐射亮温一致性。4、研制了8mm微波辐射计。该辐射计的设计充分考虑了绝缘子及其污秽的特点,具有低噪声前端和窄波束天线设计的特点。辐射计的主要性能指标如线性度、灵敏度、稳定度和定标方程等满足测量要求。5、提出了污秽多维监测方法。分析了工程实践中污秽监测的问题,采取多维技术来减少监测误差,给出了区域污秽监测系统的技术方案。更多还原

【Abstract】 Power system pollution flashover occurs frequently, and the loss is enormous. Insulator surface contamination monitoring the situation can be effective early warning and guidance to line maintenance. For detection of insulator contamination has been a hot and difficult topic. According to microwave radiation theory, in this paper, the insulator contamination detection technologies and methods is researched systematic, and the major jobs and innovations are made as follows:1. A microwave radiation measurement method to detect insulator contamination is proposed. A formula to calculate antenna temperature of insulator contamination and inversion formula of brightness temperature are derived theoretically, the theoretical and technical implementation is determined.2. A model of the brightness temperature of radiation contamination is proposed. The model parameters are analysised. These parameters include the emission rate, contamination layer thickness, insulator material, operating frequency, polarization, and angle measurement. The relationship between brightness temperature and ESDD and the relationship between complex dielectric constant and ESDD are researched. The study shows that the complex dielectric constant of contamination is internal basis to change contamination brightness temperature of radiation. The relationship between ESDD and the complex dielectric constant is studied further by experimental.3. A mathematical model to calculate ESDD/NSDD with brightness temperature is proposed. The model tested by the regression equation is correct. The model shows that relationship between brightness temperature and ESDD/NSDD meet the power function. The ESDD and NSDD can be solved with measurements data under wet and dry conditions. The relationship between the brightness temperature and ESDD or NSDD for XP-70 type is researched by experiment. The results show that the applied high voltage has no direct impact on the antenna temperature, natural and artificial dirty brightness temperature has the same characteristics. The microwave radiation to detecte insulator contamination has a project value.4. An 8mm microwave radiometer has been developed. The radiometer is designed with low-noise of the first circuit and the narrow-beam antenna taking into account the characteristics of insulator contamination. The main performance of linearity, sensitivity, stability and calibration equation meet the needs of measurement.5. A multi-dimensional method for pollution monitoring is proposed. Analysis of the project to detect pollution problems in practice is made. A multidimensional detection method is adopted to reduce the testing error. A technology program of regional contamination detection system is given.更多还原