Magnetic Eddy-Current, Fluid and Thermal Coupled Model for the Finite Element Behavior of Gas-Insulated Bus Bars

Abstract

This paper describes a coupled magnetic eddy-current, fluid and thermal finite-element model to analyze the steady and transient thermal behavior of a three-phase gas-insulated bus bar (GIB). The magnetic eddy-current field is indirectly coupled into the fluid and thermal fields through the power loss density while considering the temperature dependent electrical conductivity. As a new methodology, multiple species transport technique is introduced into the thermal model using computational fluid dynamics (CFD), circumventing the difficulty of applying temperature and geometry dependent heat transfer coefficient on the model boundaries. Good agreement is found between the CFD and experimental results. The proposed methodology is further used to predict the steady and transient thermal behaviors of the GIB under the effects of various gas pressures, gas types, electrical loads, and ambient temperatures, which provides useful sensitivity information for GIB designers in the product development process.