Research On Metal Oxide Surge Arrester On-line Monitoring Principle And System

With the increasing quality of power supply requirements, the requirements are also increasing the safety and reliability of the power system. Wherein zinc oxide surge arresters (Metal Oxide Surge Arrester, MOA) as an important overvoltage electrical appliances, can effective protection of other electrical equipment. Because it also has the reaction speed, flow capacity, small size, and many other advantages, the power system has been applied widely. Therefore, the performance of the pros and cons of zinc oxide surge arresters directly affect the safe operation of the power system. At present, the analysis and judgment of zinc oxide surge arresters whether there is a fault, the most effective method is resistive current monitoring arrester leakage current.This paper first introduces the structure, electrical characteristics and equivalent circuit of the metal zinc oxide surge arresters (MOA) on monitoring arrester resistive current methods and principles of the characteristic quantities such as third harmonic law, compensation law, Xilin bridge dielectric loss measurement method, harmonic analysis on the various principles of analysis proposed algorithm applies occasions, for the study of high precision, full-featured arrester line monitoring and fault diagnosis device provides a theoretical basis.The system studied by the hardware and software parts, wherein the hardware part of the current sampling unit, a voltage sampling unit, a signal processing unit and other components; place mainly to complete the data acquisition, digital to analog conversion, computing and communication functions, provides redundant fiber I interface, to achieve inter devices and devices and back-end systems (including CAC) communications. Software part of a distributed real-time database, interactive interface and other components, all of the data elements collected summarize, considering various confounding factors, while, according to the wavelet transform, gray correlation analysis, mathematical morphology, fuzzy neural network, combined with lightning expert judgment, the experience of the manufacturer of a comprehensive line arrester monitoring and fault diagnosis.Engineering application of this system may malfunction before arrester for real-time condition assessment and analysis, we found the internal device arrester latent failures in the first time, thus preventing failure or in the event of a fault condition can be targeted, rapid troubleshooting, and then to safe and reliable operation of the power system to provide effective protection...