Magnetic Circuit Model of a Distributed-Winding Brushless DC Motor for Use in SPICE (Applied Magnetics)

This paper presents a method for calculation of the dynamic characteristics of a brushless dc motor (BLDCM) with a distributed winding. The calculation method is based on reluctance network analysis (RNA). In the analysis, the stator, rotor, and gap are expressed as a reluctance network circuit and controlled voltage sources for the magnetomotive force of the permanent, magnets of the rotor. By combining a driving inverter circuit and controlled system with a reluctance network circuit, we can readily calculate the dynamic characteristics of the BLDCM, including the distribution of flux density inside the BLDCM. The calculated results agree well with the experimental data. The calculation method proposed here is useful for optimum design of BLDCMs.