Shape optimization of coronashield geometry : Simulation techniques for minimizing electricfield with COMSOL 6.0

Sammanfattning: This report focuses on the practicality and results of using the COMSOL 6.0 Optimization Module on a HVDC bushing corona shield model provided by Hitachi Energy to minimize electric field. The Optimization Module has several functions and parameters for altering the geometry of a model. Parameter Optimization, Polynomial Boundary and Free Shape Boundary was the primary methods used. The best results in minimizing the electric field was found with the Polynomial Boundary. The optimized shape decreased the maximum electric field by about 15% and when run with constraints to the change in volume the optimization showed similar results. Tests with Parameter Optimization did decrease the electric field but lacked the ability to fine-tune the shape like Polynomial Boundary can. Free Shape Boundaryseemed to have great potential in the documentation but we did not finda successful way of implementing the method. Through testing of different setups for methods and solvers we have concluded that the Optimization Module is both useful and practical for the given model and a clear improvement in electric field was observed in the new shape. Polynomial Boundary is the best option for the given model but more research is needed about Free Shape Boundary.