Model-based Location of Segmental Aging for Underground Power Cables in Distribution Grids

Power cable in distribution grids usually operates in nonuniform environments, leading to segmental aging of cable insulation. Location of segmental aging is highly desirable for early maintenance of power distribution grids, which can avoid severe insulation faults and improve system reliability. In this paper, a novel segmental aging location method based on voltage and leakage current measurements under multi-frequency common-mode (CM) monitoring signal injection is proposed. Segmental aging models for various types of cables are first developed, and a model-based location algorithm of segmental aging is then designed. Comprehensive simulations and case studies in PSCAD/EMTDC are conducted to prove the effectiveness of the proposed method. Compared with existing approaches, the proposed method achieves more accurate location of aging accounting for various measurement noises, parameter uncertainties, and distribution grid structures.