Aiming at the problem of excessive local temperature rise in UHV air-core reactors working under highcurrent operating conditions

this paper takes a 1 100 k V UHV oil-immersed air-core reactor as the research objectand constructs a two-dimensional axisymmetric calculation model of electromagnetic field-flow field-temperaturefield of the reactor at an ambient temperature of 20 °C. In the model

the convective heat transfer process of the inter-nal insulating oil adopts a flow-heat coupling method

and the heat exchange process between the outer air and theouter wall of the reactor as well as the bottom of the reactor and the earth is described by adding a corresponding con-vective heat transfer coefficient

thereby the distribution of hot spots inside the reactor and the distribution of the ve-locity of the insulating oil are calculated. The results show that the insufficient flow of insulating oil is the cause of lo-cal overheating. The temperature distribution can be effectively optimized by reducing the viscosity of the insulatingoil and widening the top oil passages.