This paper presents a simplified heat transfer analysis of the generator armature bar region near a resistance temperature detector (RTD). During generator operations, heat is generated in the generator due to the various losses. With conventional indirect cooling, heat is removed from copper conductors to the steel core through the conductor insulation. It is desired to minimize the thermal resistance to achieve the highest heat transfer rate.
Heat transfer characteristics in the generator armature bar region were obtained using an FEM model. Results show that the RTD temperature is primarily determined by the boundary temperatures on the copper conductor and silicon-iron walls, and thermal conductivity of RTD and armature bar insulations. Sensitivity studies have been performed to help engineers to optimize generator designs.