基于可听声波的GIS击穿点定位方法

Location Method of Breakdown Points in GIS Based on Audible Sound Waves

为提高气体绝缘组合开关(GIS)击穿点定位的效率和有效性,基于空间可听声波提出了一种实施简单、定位准确的GIS击穿点二维定位方法。通过分析GIS击穿可听声波的特点,提出了确定声波信号到达不同传感器时延的峰值-阈值法。采用3个声波传感器的一形布置方式,结合空间算法搭建了无接触式的GIS击穿点数字化定位系统,并应用于330kV GIS现场试验。研究结果表明,GIS内部发生击穿时会向外辐射可听声波,声波的时域波形具有明显的高幅值脉冲,频域波形主要分布在2～8kHz,明显区别于背景噪声并为GIS击穿点的定位提供可用信息。330kV GIS的应用结果表明,定位系统的定位误差小于5%,与超声波、特高频等接触式定位方法相比降低了GIS击穿点定位的难度和成本,为GIS击穿点的现场定位提供了一种新的思路。GIS击穿点的定位结果受到声波传播衰减、传感器系统位置和遮挡物的影响,实际应用中需合理布置定位系统以提高定位结果的有效性和准确性。

Traditional contacted GIS breakdown point location methods require a large number of sensors and have poor anti-interference ability.In the withstand voltage test for a GIS,especially in the impulse voltage test,these methods cannot locate the breakdown point in most cases.In order to improve the efficiency and effectiveness of the positioning,this paper puts forward a simple and accurate two-dimensional location method of breakdown points in GIS based on the theory of spatial audible sound waves.By analyzing the characteristics of acoustic waves from the breakdown of GIS,a peak-threshold method to determine the time delay of a GIS breakdown sound wave arriving at different sensors is presented.The digital positioning system is set up by using the horizontal arrangement of three acoustic sensors,and the sensors have no physical contact with the detected GIS.Results show that the acoustic waveform caused by GIS breakdown has an obvious high amplitude impulse in time domain,and mainly distributes from 2 kHz to 8 kHz in frequency domain,which can be clearly distinguished from the background noise and provide useful information for localization.Experimental results of 330 kV GIS show that the location error of the proposed system is under 5%,and compared with the ultrasonic and UHF location methods,the audible sound method reduces the difficulty and cost in positioning of breakdown points in GIS.The attenuation of waveform,the position of the sensor system and the barrier between GIS and the positioning system may influence the positioning result,so the positioning system should be reasonably arranged in practical application.