An Accurate Nonlinear Model for Design of DFIGMs Considering Saturation Effects Based on Subdomain Method and Morphology

This article presents a nonlinear model (NLM) of electromagnetic characteristics (ECs) for the doubly fed induction generator motors (DFIGMs) under multiple conditions, used in marine power systems. The proposed model combines the accurate subdomain method (ASM) for linear EC calculation with mathematical morphology (MM) for saturated feature extraction. In detail, the B–H network tables of the soft magnetic material and the morphological operator dilation and erosion calculations are used to correct the magnetic flux density caused by teeth saturation. It also greatly simplifies the model construction and computation. Furthermore, the analytical merits and applicability of the model are discussed. Finally, multicondition experiments are conducted on a 10-MW DFIGM to verify the validity of the model. The results indicate that this model can ensure computational accuracy and reduce computation load with the generic nature of the proposed methodology.