Mechanical Design Considerations of a Light-Weight Rotor for Brushless Double Fed Machines

This paper presents an optimised mechanical design aimed at reducing the rotor mass of a Brushless Doubly-Fed Machine (BDFM). The focus is on the rotor back iron, identifying specific areas where iron materials can be removed without compromising the magnetic performance of the rotor. Mechanical stress and vibration analyses are conducted using the Finite Element (FE) method in Ansys software to evaluate the feasibility of the proposed design. The study is performed on a prototype D400 250-kW BDFM, showing that the rotor mass can be reduced by approximately 24% while maintaining acceptable electromagnetic and mechanical performance under rated operating conditions.