Simulation of the Filling of Epoxy in Resin Impregnated Paper Bushings : Analysis of Temperature Measurements during Filling of Epoxy and the Generation of New Filling Recipes to Avoid Cavities in the RIP Bushing

Abstract: The goal of the project was to create a model in COMSOL Multiphysics that can simulate thefilling of resin (epoxy) in Resin Impregnated Paper (RIP) bushings. Using the model new fillingrecipes that avoid problematic double-fronts and thereby avoid the creation of cavities in thebushings should be designed. Another goal was to use Thermocouples and Fiber optics tomeasure the temperature at different positions during the filling to get a better understanding ofthe filling. The first step was to design and determine functions, parameters (such as thepermeability), boundary conditions etc. for the simulation model in COMSOL Multiphysics and tocalibrate the model to align with measurements of fillings previously done. The second part wasto increase the filling time to minimize the maximum difference between filling fronts in thebushings and thereby decrease the risk of problematical double-fronts that create cavities,which decrease the bushing's dielectrical properties. The simulation model aligned somewhatwith the measured data but there is a lot of uncertainty both in the measurements and due toassumptions made in the simulation model. The measurements from Thermocouples and Fiberoptics where almost identical and they indicated that the filling of the bushing is symmetric.