The condition diagnosis of XLPE cable insulation based on fuzzy clustering method

The condition diagnosis of XLPE cable insulation was studied in this paper. The AC breakdown test and differential scanning calorimetry (DSC) measurement were conducted to investigate the dependence of ageing state on thermal and dielectric parameters. The results show that the breakdown strength increases slightly at first and then decreases significantly with the ageing time, which is closely related to the crystallinity. Besides, it is shown that a strong correlation exists between macro properties and microscopic parameters. Then the effective parameters obtained from various parameters according to two-dimensional fuzzy clustering for diagnosing the condition of XLPE cable insulation include tensile strength, breakdown strength, activation energy and carbonyl index. Finally, a comprehensive model for evaluating the state of cable insulation based on fuzzy diagnosis is proposed, which is proved applicable via case study.