摘要
为研究电缆终端局部放电超声波检测时放电点深度对检测结果的影响,根据检测结果有效分析放电点位置及放电严重程度,采用理论分析、模拟计算、实验室模拟实验、现场应用等方式,结合超声波传播及衰减理论,分析了放电信号在电缆终端表面的沿切向、沿轴向衰减的分布规律,提出了通过迭代及最小二乘法进行局部放电点的源点深度及真实放电水平计算的方法。结果表明:信号量随轴向距离与夹角增大而减小,放电点深度对信号量随放电点与测量点间的轴向距离与夹角的变化率影响较大,放电点深度越小,变化率越大,反之变化率越小。模拟实验与现场应用表明,通过文中的迭代法得到的放电点深度及放电水平与实际基本相符。
This paper studies the influence of the discharge point depth on the ultrasonic detection results of partial discharge in cable terminals to find an effective method to analyze discharge position and discharge level according to the results of cable terminal discharge ultrasonic signal field test. With ultrasonic wave propagation and attenuation theory, this paper analyzes the tangential and longitudinal distribution pattern of discharge signals in cable terminal surface and puts forward a calculation method about the true depth and discharge level of partial discharge source on the cable terminal by the way of theory analysis, simulated calculation, laboratory test and field application. The result reveals that the detected ultrasonic signal level decreases as the axial distance or the central separation angle between the discharge point and the test point increases, and the depth of discharge point influences the change rate of the detected ultrasonic signal level along with the axial distance and the central separation angle. The lower depth means the larger change rate and the higher depth means the less change rate. It＇s also revealed that the measured discharge point depth and discharge level by the proposed iteration method are consistent with real situation.
出处
《重庆大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2014年第6期112-118,共7页
Journal of Chongqing University
基金
安徽省电力公司2009年科技项目(2009146)
关键词
电缆终端
局部放电
最小二乘法
放电点深度
放电水平
cable terminals
partial discharges
generalized least square
discharge point depth
dischargelevel
