Affiliations: [a] Liaoning Key Lab of Modern Electrical Equipment Theory and Common Technologies, Shenyang University of Technology, Shenyang, China | [b] TBEA Shenyang Transformer Group Co. Ltd, Shenyang, China
Correspondence:
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Corresponding author: Baodong Bai, Shenyang University of Technology, China. E-mail: baibd@sut.edu.cn
Abstract: The dielectric parameters of oil-immersed insulation paper, semi-conductive paper and mineral oil were measured at different temperature. The quantitative analysis about the influence of the equalizing cage density on the Inverted-type Oil-immersed Current Transformer (IOCT) electric field distribution was studied, and the temperature dependence of the insulation material dielectric parameters were taken into consideration. In high temperature conditions, the oil-paper damage of IOCT insulation system is generally not caused by electric breakdown but heat aging. The maximum electric field strength of oil-paper I is approximately reduced by 12.84%, and that of the oil-paper II is reduced by 0.35%, after the equalizing cage density is increased. The increasing of the equalizing cage density will be beneficial to the electric field equidistribution of the IOCT insulation system.
Keywords: IOCT, electric field equilibrium characteristics, equalizing cage, insulation parameter
