Affiliations: [a] State Key Laboratory of Power Transmission Equipment & System Security and New Technology, Chongqing University, Chongqing, China | [b] State Grid Shandong Electrical Engineering & Equipment Group Company, Ltd., Shandong, China | [c] State Grid Zhejiang Electric Power Company, Ltd., Zhejiang, China
Correspondence:
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Corresponding author: Liu Heng, State Key Laboratory of Power Transmission Equipment & System Security and New Technology, Chongqing University, Chongqing 400044, China. Tel.: +86 18883480505; Fax: +86 023 65102434; E-mail: liuheng_sw@cqu.edu.cn
Abstract: The special working condition of shore power cable is more likely to form a crack air gap in insulating medium, which will cause gap discharge. The continuous gap discharge will cause local temperature rising and stress concentrating, which will lead to cable insulation deterioration. The electro-thermal-stress coupling method, in this paper, is used to establish the finite element model of the shore power cable. The electric, temperature and stress field distribution for the shore power cable with a crack air gap in the insulating medium is also studied, and the correctness of temperature and stress field distribution is verified by experiments. In addition, this paper investigated the variation law of the ampacity for shore power cable under different discharge energy. The results show that the maximum electric field is equal to the electric field intensity (36.1 kV/cm) at the inner edge of the insulating medium when the gap length d = 2 mm and that the temperature and stress of the cable are quadratic with load current, linear with the gap discharge energy. The research results of this paper have an engineering significance for monitoring shore power cables.
Keywords: Shore power cable, multi-physics field, discharge energy, ampacity
