GIS金属法兰孔处的VFTO测量系统设计

内置式VFTO的测量传感器体积大、安装困难,不适用于在运的特高压GIS。针对以上缺陷,文中设计了一种适用于GIS金属法兰孔处的VFTO测量系统。该系统采用FPC电容分压与二次阻容分压器结合的方案,实现了GIS外置小型化的VFTO测量。根据金属法兰孔的尺寸及测量系统的性能要求,对FPC进行结构、尺寸设计,研制了电容分压探头。为改善测量系统的性能,设计了宽频阻容分压器,并通过实测的方式对匹配电阻与同轴电缆的参数进行优化。试验结果表明,VFTO测量系统的带宽为22.45 Hz~111.45 MHz,分压比为112 790,可以准确溯源波形,满足VFTO测量要求。

Design of VFTO Measuring System at the Metal Flange Hole

The measurement sensor of the built-in sensor for VFTO is large in size and difficult to install, and cannot be applied to GIS in operation. In order to solve these problems, the VFTO measurement system for GIS metal flange holes is designed. The system adopts the scheme of combining FPC capacitor voltage divider and secondary resistance-capacitor voltage divider to realize VFTO measurement with external miniaturization of GIS. According to the size of the metal flange hole and the performance requirements of the measurement system, the structure and size of the FPC are designed, and the capacitance partial pressure probe is developed. In order to improve the performance of the measurement system, a broadband resistance-capacitance voltage divider is designed, and the matching resistance and the parameters of the coaxial cable are optimized through actual measurement. The results show that the bandwidth of VFTO measurement system is 22.45 Hz~111.45 MHz, and voltage division ratio is 112 790, indicating that the proposed system can accurately trace the source waveform and meet the requirements of VFTO measurement.