非接触式局部放电检测天线的设计和优化研究

Design and Optimization Study of Detection Antenna for Noncontact Partial Discharge

为实现基于超高频(UHF)法非接触式检测一定范围内电气设备局部放电(PD),需要研制合适的天线作为超高频(UHF)传感器。锥形天线具有宽频带、高增益和水平面(H面)全向性的特点,文章选取该型天线进行分析,研究其尺寸参数对天线性能的影响,得出该天线的设计规律。通过天线性能分析再结合PD检测的要求,最终选择锥高30cm、锥角45°的锥形天线作为非接触式PD检测的UHF传感器。经测试该天线频带为200MHz^2GHz以上,在200MHz^2GHz频带内平均增益达4.5dB以上,在对较远距离外模拟放电信号的接收试验中表现出良好的UHF信号接收能力,完全达到设计要求。基于该天线可以开发出固定式或车载式PD监测系统,该系统可以监测整个变电站设备PD情况并且其工作时不与设备发生接触。

For noncontact detecting partial discharge of electrical equipments within range limit based on ultra-high frequency method,suitable antenna needs to be developed as UHF sensor.Cone antenna has advantages of wideband,good gain and horizontal plane omnidirectional,this paper analyzed this kind of antenna,researched the relation of the size and the antenna performance,concluded the design rule of cone antenna.Cone antenna with cone height 30cm and cone angle 45° was chosen as UHF sensor for noncontact detecting PD according to performance analysis combined with PD detecting demand.The measurement result showed that the bandwidth of the cone antenna is from 200MHz to above 2GHz,the average gain from 200MHz to 2GHz can get to above 4.5dB and showed good performance on UHF signals receiving after test of detecting analog discharge signals from far away,satisfied the design demand.Fixed and mounted PD monitoring system can be developed based on this antenna,the system can monitor PD of electrical equipments within substation and can be noncontact to equipments.