基于Fréchet相似度的套管频域介电谱诊断方法

Dielectric Spectrum Diagnosis Method of Bushing Frequency Domain Based on Fréchet Similarity

频域介电谱(frequency domain spectroscopy,FDS)测试具有无损化、频带宽、信息丰富等优点而广泛应用于充油设备诊断。但是,利用FDS测试曲线受套管结构、类型影响较大,对现场测试结果判断造成不便,为此提出了一种基于Fréchet相似度的FDS套管缺陷诊断方法。首先根据不同结构、电压等级对缺陷套管进行现场FDS测试;继而研究了套管电介质响应模型,揭示不同频段测试曲线所对应的不同缺陷类型,并提出基于Fréchet相似度的套管现场FDS测试诊断判据;最后结合套管现场FDS测试缺陷案例,得出套管FDS测试曲线在低频段(0.01 Hz以下)可以反映套管受潮缺陷,在中频段(0.01~10 Hz)反映套管油老化程度。

Frequency domain dielectric spectroscopy(FDS)test is widely used in oil-filled equipment diagnosis due to its advantages of lossless,frequency bandwidth and rich information.However,the FDS test curves are greatly affected by the bushing structures and types,which may cause inconvenient judgement of site test results.Therefore,this paper proposes a kind of diagnosis method for FDS bushing defect based on Fréchet similarity.Firstly,it carries out site FDS test according different structures and voltage levels.Afterwards it studies the bushing dielectric response model,reveals different defect types corresponding to different frequency band test curves and presents the diagnosis criteria for site FDS test based on Fréchet similarity.Finally,combining with the defect cases of site FDS test,it draws conclusions that the FDS test curves in the low frequency band(below 0.01 Hz)can reflect the damp defect of the bushing and reflect the aging degree of the bushing in the middle frequency band(within 0.01~10 Hz).