冲击电压激励下变压器套管介电响应快速测量方法

Fast Measurement Method of Dielectric Response of Transformer Bushing Under Impulse Voltage Excitation

油纸绝缘套管作为变电站内极为重要的电力设备之一,其绝缘状态对于电力系统的安全稳定运行至关重要。频域介电谱法可实现套管绝缘状态的无损检测,但传统扫频测试耗费时间长,为频域介电谱的现场应用带来不便。文中提出一种冲击电压激励下变压器套管介电响应快速测量方法,利用冲击电压信号中包含的丰富频率分量作为激励信号,获取套管末屏响应电流并进行数据处理与计算,从而得到频域介电响应信息。文中基于扩展德拜模型,搭建冲击电压激励下介电响应仿真平台,并利用任意波形发生器、高压功率放大器等设备搭建实验测试平台,验证了冲击电压激励下介电响应快速测量方法的可行性与准确性,对于缩短变压器停电检修时间窗口,提高现场套管绝缘状态诊断效率具有重要意义。

The insulation state of oil-paper insulating bushing,as one of the most important power equipment in substations,is very important to safe and stable operation of power system.The frequency domain dielectric spectroscopy can achieve the non-destructive test of the insulation state of the bushing.However,the traditional sweep frequency test takes a long time and brings inconvenience to the field application of the frequency domain dielectric spectroscopy.In this paper,a kind of fast measurement method for dielectric response of transformer bushings under impulse voltage excitation is proposed.The abundant frequency components contained in impulse voltage signals is used as excitation source to obtain the response current at the end screen of the bushing and perform data processing and calculation,thus obtaining response information of the frequency domain spectroscopy.Based on the extended Debye model in this paper,the simulation platform for dielectric response under impulse voltage excitation is set up and such equipment as arbitrary waveform generators and high-voltage power amplifiers are used to set up an experimental test platform to verify the feasibility and accuracy of the fast measurement method of dielectric response under impulse voltage excitation.The work in this paper is of great significance for shortening the power-off time window for transformer power maintenance and improving the diagnosis efficiency of bushing insulation status on site.