本文结合实际气体绝缘组合电器(GIS)结构、运行特点,设计了用于GIS局部放电检测的外置超高频微带贴片天线(MPA)传感器,该传感器安装在GIS盆式绝缘子处,接收盆式绝缘子处泄漏的电磁波,并对周围空间电磁干扰抑制;在选择天线基板的材料、厚度、形状,以及附加阻抗匹配网络等方面进行了频带展宽。计算和实测表明,天线的有效工作频带展宽为340~440MHz,中心频率为390MHz,相对带宽25.6%,达到宽频带天线范围,并且最大辐射和接收方向上的增益达到了5.38。实验室GIS模拟装置测量表明该天线传感器性能良好,具有较高灵敏度,可用于GIS局部放电在线监测。
Based on the structure and operating characteristic of Gas Insulation Substations (GIS), an outer UHF microstrip patch antenna (MPA) sensor for detecting the partial discharge in GIS was designed, the sensor is fixed at the basin insulator to receive the electromagnetic wave leaked from the basin insulator, and suppress the electromagnetic interference from surrounding environment. Some effective methods for expanding bandwidth are utilized in the design process, such as choosing the material, thickness and shape of the antenna base plate and adding impedance matching network. Calculation and testing show that the effective working bandwidth of the antenna is 340-440 MHz, the center frequency is 390 MHz, and the relative bandwidth is 25.6%, which reach the range of broadband antenna. Especially the gain reaches 5.38 in its maximum transmitting and receiving direction. Comparing with loop coupler built in GIS, the test results show that the proposed microstrip patch antenna satisfies the requirement of partial discharge detection; it can detect the PD signal in effective band with high sensitivity for on-line detecting in GIS.