Modeling and parametrization of DC motor winding inductances
Purpose - The purpose of this paper is to compare several methods to calculate solenoid inductances regarding their applicability to model the inductance of DC motor armature windings. Special attention is given to the influence of wiring insulation and current distribution and the axial length of the solenoid. Design/methodology/approach - Expressions for the self- and mutual-inductance of current filament and wire combinations are derived from basic inductance formulas. Combining these expressions allows expressing the inductance of arbitrary shaped solenoids (e.g. polygons). Findings - Accurately describing self- and mutual-inductances is a very complex topic. However, in the case of motor armature windings, several simplifications can be applied to lower the calculation cost significantly. Plus, differences in inductances between regular polygonial solenoids and similar circular shapes were found to be rather small. Thus, many windings' inductances can well be approximated by using expressions for circular solenoids. Originality/value - A new way to calculate the inductance of arbitrary polygonial shapes is presented, and an example is given for hexagonal shapes.
inductance simulation electric motors