Electrical Tree Defect Diagnosis Technology for XLPE Cable Based on Spectrum Characteristics of Leakage Current
The online diagnosis of cable electrical tree defects is of great significance for the stable operation of the power system.Leakage current contains rich insulation information and meets the needs of the online detection,making it a highly promising detection method that can achieve online monitoring and diagnosis.This paper conducts research on XLPE cable electrical tree defect diagnosis technology based on leakage current spectrum characteristics,and carries out related work from both experimental research and simulation analysis.Firstly,an XLPE electrical tree cultivation and leakage current detection platform was established to conduct experimental research on the morphology of the electrical tree,as well as the amplitude and spectral characteristics of leakage current,throughout the entire process of electrical tree defects from initiation to breakdown.Then,a physical field simulation model for electrical tree defects was established to calculate the distribution of electric fields under different forms,and the correlation between electric field characteristics and leakage current spectrum characteristics was analyzed.The research results indicate that around 15 minutes before the breakdown,the amplitude of the leakage current changes from 585.3 μA in a short period to above 1 200 mA,THD increases from 7.7％to over 35％.Using the amplitude of leakage current and THD as characteristic parameters,it is possible to diagnose and warn of electrical tree defects before breakdown.The correlation analysis results indicate that THD is positively correlated with electric field strength,and THD has the potential as a diagnostic parameter for cable defect types.
XLPE cableelectrical tree defectdiagnosisleakage currentharmonic characteristic
万方数据
维普
