GIS隔离开关开合短母线型式试验方式1中VFTO测量系统构建及波形解析

Construction of VFTO Measurement System and Waveform Analysis for Switching Test Duty 1 of Short Busbar by GIS Disconnector

开合短母线方式1试验是考核GIS隔离开关电气性能的关键型式试验之一。在方式1试验中,需要准确测量隔离开关在试验操作过程中所产生的全过程对地瞬态电压。为此文中构建了基于电容分压传感的超宽频瞬态电压测量系统,用于方式1试验。系统包括VFTO传感器、监测终端以及控制单元,模拟带宽和系统采样率分别是100 MHz和250 MS/s。监测终端采用隔离变压器进行供电,有效提升了系统的抗干扰能力。文中以1100 kV GIS隔离开关作为试品,全过程监测了隔离开关方式1试验过程中交流侧和直流侧的瞬态电压波形。结合被试品的结构尺寸,分析了被试品两侧全过程瞬态电压的时域和频域特征。同时还分析了被试品的内部发生击穿时,隔离开关两侧所测电压信号的异常变化特征,形成了有效的内部击穿判据。通过1100 kV GIS隔离开关方式1试验,验证了文中所构建瞬态电压监测系统优异的测量和抗干扰性能,为GIS隔离开关的性能考核和优化设计提供了有力的支撑。

Switching test duty 1 of of short busbar is one of the key type tests to evaluate the electrical performance of GIS disconnector.In the test of test duty 1,it is necessary to accurately measure the whole process transient voltage to ground generated by the disconnector during the test operation.For this purpose,an ultra⁃wideband transient voltage measurement system based on capacitive voltage divider is constructed for test duty 1.The measurement system in⁃cludes VFTO sensors、monitoring terminals and control unit.The analog bandwidth and system sampling rate are 100 MHz and 250 MS/s,respectively.The monitoring terminals are powered by isolated transformers,which effec⁃tively improve the anti⁃interference ability of the system.In this paper,the 1100 kV GIS disconnector is taken as an example,the transient voltage waveforms of AC and DC side of 1100 kV GIS disconnector are monitored during test duty 1.Both time domain and frequency domain characteristics of the transient voltage on both sides of the proto⁃type during the whole period are analyzed in combination with the structural dimension of the prototype.At the same time,the abnormal variation characteristics of the voltage signals measured on both sides of the disconnector in case of internal breakdown are analyzed,and an effective internal breakdown criterion is formed.Throughout test duty 1 of 1100 kV GIS disconnector,the excellent measurement and anti⁃interference performance of the transient voltage monitoring system is verified,which provides a strong support for the performance assessment and design optimization of GIS disconnector.