The modeling problem associated with brushless DC motors (BLDCMs) with nonuniform air gaps which operate in a range where magnetic saturation may exist is addressed. The mathematical model, includes the effects of reluctance variations and magnetic saturation to guarantee proper modeling of the system. An experimental procedure is developed and implemented in a laboratory environment to identify the electromagnetic characteristics of a BLDCM in the presence of magnetic saturation. It is demonstrated that the modeling problem associated with this class of BLDCM can be formulated in terms of mathematically modeling a set of multidimensional surfaces corresponding to the electromagnetic torque function and the flux linkages associated with the motor phase windings. The accuracy of the mathematical model is checked against experimental measurements


Mechanical and Aerospace Engineering

Keywords and Phrases

DC Motors; Brushless DC Motors; Electromagnetic Characteristics; Electromagnetic Torque Function; Flux Linkages; Machine Theory; Magnetic Saturation; Mathematical Model; Nonuniform Air Gaps; Phase Windings; Reluctance Variations

Document Type

Article - Journal

Document Version

Final Version

File Type





© 1990 Institute of Electrical and Electronics Engineers (IEEE), All rights reserved.

Publication Date

01 Jan 1990