强电磁场对1000 kV 等电位在线验电器的影响和防护措施

摘要

等电位在线验电器在运行过程中受强电磁场的干扰。在1000 kV的特高压线路上，干扰尤为明显。其现象包括LED亮起后无法完全关断、闪烁间隔时间不稳定等。从强电磁场对等电位在线验电器的干扰入手，根据高压试验测量的数据，分析强电磁场对LED元件和控制元件的影响，并寻求相应的防护措施。试验结果表明，加装屏蔽防护金属网和采取多芯片堆放再厚膜封装的电路集成，可有效减少强电场对验电器的干扰。通过优化电路板设计、增加铁磁材料金属箔、前端增加瞬变抑制二极管等辅助措施，可进一步保证1000 kV等电位在线验电器在强磁场和瞬时过电流的环境下仍能正常、稳定工作。%Equipotential on-line electroscope is prone to the interference by high electromagnetic ( EM) field during its opera-tion, especially in 1 000 kV UHV transmission line.The interference makes LED cannot be completely switched off and leads to irregular LED flashing .In order to overcome these problems , the influence of high EM field on LED components and control components is analyzed according to the measured data of HV test , and the corresponding protective measures are found out . Test results show that it can effectively reduce the interference to electroscope from high EM field by installing metallic mesh as shielding and using the integration of circuits with multi -chip module and thick -film package .Through optimizing the de-sign of circuit board , adding metal foil of ferro-magnetic material and installing transient voltage suppressor , it can ensure the normal and stable operation of 1 000 kV equipotential on -line electroscope under the interference of high EM field and transi-ent over-current.