Design and Optimization of a 4-6 Brushless Doubly Fed Induction Generator

This paper provides an outline of the brushless doubly fed (induction) machine (BDFM) design process, introducing modifications to the comprehensive BDFM power ratings formula. The modifications introduced seek to simplify the calculation methodology for the D2L design coefficient, offering a more simplified approach. In this paper, insights regarding the selection process involving the stack length ratio, electric loading, and airgap flux density and distribution are presented. The analytical design methodology is subsequently applied to an 11 kW BDFM housed in a D225M frame, followed by optimization using the NSGA-II (Non-Dominated Sorting Genetic Algorithm II). This BDFM features a nested loop rotor, enabling unity power factor on the grid-connected winding.