超小型内置柔性宽频带UHF单极子天线传感技术

Sensing Technology for Ultra-small Built-in Flexible Wideband UHF Monopole Antenna

特高频(ultra high frequency,UHF)法是电力设备局部放电(partial discharge,PD)绝缘缺陷常用的检测方法,在内置安装空间受限的情况下保证UHF天线具有良好的PD高频电磁波信号感知性能至关重要,基于聚亚酰胺(polyimide,PI)柔性基底设计了一种小型化UHF单极子天线,尺寸仅为58 mm×36.8 mm×0.3 mm,相较于传统单极子天线结构缩小了50.4%,并且通过对辐射区镂空和弯折处理改善了天线的低频性能。仿真和实测表明,设计的柔性天线在绝缘油和SF6绝缘气体中的有效带宽分别达到360 MHz~2.35 GHz与440 MHz~1.78 GHz,可全向接收PDUHF信号且弯曲形变后天线能保持良好的辐射性能。最后,搭建220kV真型气体绝缘组合电器和变压器PD模拟实验平台,对柔性天线在不同绝缘缺陷下的PD检测性能进行实测。结果表明,柔性天线内置后能有效检测到低放电量下的PD UHF信号,具有较高的灵敏度,可满足电力设备PD检测需求。

Ultra-high frequency(UHF)method is commonly used to detect partial discharge(PD)insulation defects of transformers,gas insulated switchgear(GIS),etc..It is very important to ensure that UHF antenna has good PD high-frequency electromagnetic signal sensing performance under the limited built-in installation space.In this paper,a miniaturized UHF monopole antenna is designed based on polyimide(PI)flexible base.Its size is only 58 mm×36.8mm×0.3 mm,which is 50.4%smaller than that of the traditional monopole antenna,and its low-frequency performance is improved by hollowing out and bending the radiation area.Simulation and measurement results show that the effective bandwidth of the flexible antenna in insulating oil and SF6 gas can reach 360 MHz~2.35 GHz and 440 MHz~1.78 GHz,respectively.It can receive PD UHF signals omnidirectionally and keep good radiation performance after bending.Finally,a 220 kV real GIS and transformer PD simulation test platform is built to verify the PD detection performance of the antenna under different insulation defects.The results show that the built-in flexible antenna can effectively detect PD UHF signals under low discharge magnitude,which has high sensitivity and meet the PD detection demands of power equipment.