A New Shape Optimization Approach for Lightweighting Electric Machines Inspired by Additive Manufacturing

Conference · 22 July 2022

DOI:https://doi.org/10.1109/INTERMAG39746.2022.9827714· OSTI ID:1888038

Sethuraman, Latha; Vijayakumar, Ganesh

Minimizing the mass in electric machines while maintaining superior performance is a new requirement for the advancement of drivetrains used in wind energy and electric mobility. Topology optimization (TO) for lightweighting electric machines using traditional approaches typically explores a restricted design space allowed by standard parametrizable geometry and manufacturing, while advanced methods, such as cell-based density approaches, suffer from a lack of robust manufacturability constraints during the optimization process. To overcome these drawbacks, we explore a grid-independent, boundary optimization where the outer shape of the magnet is parameterized using Bezier curves. We conduct a design of experiments (DOE) to study the effect of different magnet shapes on machine performance by varying the control points on the Bezier curves. A machine-learning-based surrogate model is constructed using the data from the DOE to quantify the relationship between the control points, air-gap torque, and mass. The control points are then optimized to maximize the torque density. The approach is used for minimizing electrical steel mass in the International Energy Agency (IEA) 15-MW radial flux direct-drive wind turbine generator. The new approach to shape optimization resulted in smooth and concise shapes that can be easily additively manufactured with up to a 20-ton reduction in electrical steel mass.

• Research Organization: National Renewable Energy Laboratory (NREL), Golden, CO (United States)
• Sponsoring Organization: USDOE Office of Energy Efficiency and Renewable Energy (EERE), Wind Energy Technologies Office (EE-4W)
• DOE Contract Number: AC36-08GO28308
• OSTI ID: 1888038
• Report Number(s): NREL/CP-5000-84010; MainId:84783; UUID:0d399547-2237-4643-906f-1890ee6129da; MainAdminID:65493
• Country of Publication: United States
• Language: English

Related Subjects

Bezier curves
ENGINEERING
WIND ENERGY
additive manufacturing
parametric design
topology optimization