The Electric-Thermal Characteristics of 110 kV Transformer RIP Bushings Based on Electromagnetic-Thermal-Fluid Analysis

As the key electrical equipment of substation, it is necessary to study the electric heating characteristics of RIP bushing in order to ensure its safe and stable operation. In this paper, the multi-layer structure of the capacitor board is established by the calculation method of equal capacitance, and the distribution characteristics of the electric heating field of RIP bushing are determined by the finite element simulation software. The results show that at rated voltage, the internal electric field intensity of the capacitor core exhibits a U-shaped distribution. The surface field strength of the capacitor core near the guide bar is the highest, which is 1.69 kV/mm. Along the axial direction, the overall temperature of RIP bushing is high in the middle and lower parts and low at both ends. High in the middle and low at both ends along the radial direction. The highest temperature is 98℃, which appears in the middle and lower part of the central current-carrying guide rod. The design of air gap between the inner and outer guide bars can effectively reduce the temperature distribution. The research results can provide theoretical and practical basis for the optimal design of high voltage AC RIP bushing.