测量快速暂态过电压的宽带预埋环传感器的研制

Development of Broadband Sensor Using Floating Ring Electrode Embedded in a Spacer for Measuring VFTO

为解决现有测量快速暂态过电压(VFTO)的盆式绝缘子预埋环传感器带宽较窄(2MHz)的问题,研制出带宽较宽的预埋环传感器,以传感器的等效电路为基础,分析了影响传感器测量带宽的主要因素,提出了提高带宽的多种措施,最终研制出了一种±3dB带宽为10Hz～16MHz的宽带预埋环VFTO传感器。应用该传感器对750kV官亭变电站GIS内特定情况下的VFTO进行了测量,测到的VFTO最大值为947kV(标幺值为1.45),最大陡度为5.3kV/ns,主要频率成分为430kHz和3MHz。研究结果表明,通过减小传感器寄生电感因素、合理选择传感器电容,可以设计出带宽更宽的预埋环式传感器,使得其可以适应一定条件下对VFTO的测量。

The bandwidth of existing VFTO sensor based on the floating ring electrode embedded in a spacer was excessively narrow（2 MHz）,so the factors of affecting the bandwidth were analyzed based on the equivalent circuit of the sensor.A series of improvement measures were taken to broaden the bandwidth of the sensor,and the method of determining parameters of the sensor was given.Moreover,a new VFTO sensor based on the embedded ring in a spacer was developed,which had a wider bandwidth.The demarcated sensor had a bandwidth of 20 Hz^16 MHz（±3 dB）.By using this system,the VFTO on the power supply side under special operating conditions of a 750 kV substation was measured.According the measurement data,the maximum VFTO of 6 operations was 947 kV.The typical VFTO oscillation had a rise time of 60 ns,a steepness of 5.3 kV/ns,and a primary frequency constitution of 430 kHz and 3 MHz.The results show that,by reducing the parasitic inductance of the sensors and choosing a reasonable value of capacitance sensors,a wider bandwidth sensors based on an embedded ring can be designed,and the sensor can be adapted to the measurement of VFTO on certain conditions.