| Metal Oxide Surge Arrester(MOA)is to guarantee the safe operation of the power system, one of the important equipment is mainly used for limits caused by line from lightning overvoltage or operation of internal overvoltage. It has a fast response, flat volt-ampere characteristics, stable performance, big flow capacity, low residual, long service life, the advantages of simple structure, widely used in power generation, transmission, substation, power distribution system. Increases with the increase of voltage level, equipment capacity, equipment failure maintenance time longer and longer, cost more and more is also high, seriously affect the reliability of power supply. MOA to security, stability and economic operation of the power system is of great significance.In the operation of MOA due to long-term directly under power frequency voltage function degradation phenomenon, cause the change of MOA resistance characteristics and current increase. In addition, the structure is bad, and make the lightning arrester internals and untight seal valve slice of be affected with damp be affected with damp, also causes in the operation of MOA impedance component current has increased dramatically, ultimately damaged due to overheating, serious when can cause the explosion of the arrester, causing large area power outage. Therefore, in order to discover the defect to fundamentally solve the problem of MOA of safe and reliable, need for real-time online monitoring of lightning arrester, implement effective real-time condition monitoring of zno arrester, in turn, determine its health, provide guarantee for the safe operation of the MOA.At present, power metal zinc oxide lightning arrester performance testing mainly used in detection is given priority to, because in the state overhaul mode and equipment under high reliability requirement, the future state of arrester inspection gradually by the power failure test to charged. Contrast is the principle of MOA within the substation insulation monitoring and resistance current measurement method, determine the impedance current calculation method is adopted in this paper. Developed using micro wear heart type zero flux current sensor to collect current signal arrester insulation online monitoring hardware system, at the same time using a set of fibre-optical data acquisition system based on fibre-optical digital monitoring lightning arrester leakage current signal and arrester actions count.Through debugging and running, the scene of the system has the function of each part has reached the design requirements. |
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