500 kV电容式电压互感器受潮故障原因

Reasons for 500 kV Capacitive Voltage Transformer Damped Fault

CVT由于具有性能稳定,不会引起电网铁磁谐振等诸多优点,在电网中得到了越来越多的应用。但是CVT生产中因工艺处理不当、运行维护不到位等原因进水受潮,严重威胁到电网安全、稳定和可靠运行。然而常规受潮故障分析手段仅针对CVT介质损耗或者电容量的变化趋势,缺乏系统性和全面性。针对同型号6组500 kV CVT,结合1台新的同型号产品,从一/二次绕组的绝缘电阻、中间变压器的电容及介损、中间变压器的耐压、绝缘油色谱、淋雨等方面做比对性试验,系统全面地分析CVT受潮原因。

Due to its stable performance and many advantages such as no ferromagnetic resonance of the power grid,CVT has been used more and more in the power grid.However,due to improper process treatment and inadequate operation and maintenance in its production,the influent water is damp,which seriously threatens the safety,stability and reliable operation of the power grid.The conventional moisture fault analysis methods are only based on the change trend of its dielectric loss or capacitance,which lacks systematic and comprehensive.For 6 groups of 500 kV CVTs of the same model,combined with a new product of the same model,From the insulation resistance of the primary/secondary winding,the capacitance and dielectric loss of the intermediate transformer,the withstand voltage of the intermediate transformer,the chromatography of insulating oil,and the rain,etc.,the comparative test is carried out to systematically and comprehensively analyze the cause of the CVT damp.