高速铁路牵引变电所220 kV干式电流互感器介质损耗值在线监测研究

为了解决离线预防性试验监测京广高铁牵引变电所220 kV干式电流互感器存在的诸多问题，依据绝缘介损的物理模型，采用过零监测比较法，设计一套220 kV干式电流互感器实时在线监测装置。在设计过程中，认真分析了电流传感器、高次谐波、过零比较器失调电压和零漂以及环境温湿度等因素对tanδ值测量精度的影响。并针对影响精度的不同因素，提出了相应的技术改进措施。现场运行情况表明，装置实时在线监测tanδ值结果与设备离线实测结果完全吻合，且运行稳定，工作可靠，满足现场运行的要求。

Research on high speed railway traction substation 220 kV dry type current transformer dielectric loss value on-line monitoring

In order to solve some problems of the off-line preventive test monitoring of Beijing-Guangzhou high-speed rail traction substation 220 kV dry type current transformer, and on the basis of the insulation dielectric loss of physical model, this paper uses the zero monitoring comparison method and designs a set of 220 kV dry type current transformer real-time online monitoring device. In the design process, it carefully analyzes influence on the tan delta value measurement precision caused by current sensor, high order harmonic, zero-crossing comparator offset voltage, zero drift, environmental temperature and humidity, etc. According to the different factors influencing the accuracy, the corresponding technical improvement measures are put forward. Field operation shows that the tan delta value results of real-time online monitoring accord with that of offline measurements, it has stable running and reliable work, and can meet the requirements of field operation.