Calculation of Active Material’s Torque Contributions for a Flux Switching Machine

A new calculation method for the torque contribution of an arbitrary point or element in an electric machine's geometry is developed. The local torque contributions (LTCs) and their visualizations provide insights into the iron utilization and possible machine geometry improvements. The flux tubes created from the magnetic vector potential's equipotential lines are interpreted as a set of local magnetic circuits (LMCs). Each LMC that crosses the air gap contributes to the machine's torque, which is quantifiable by applying the Maxwell stress tensor to the LMC's air-gap intersections. The torque contributions are mapped to all finite elements belonging to each LMC, for each transient calculation's rotor step. Furthermore, the torque contribution data are briefly discussed and a harmonic analysis is performed, focusing on the mean and ripple components of the torque. Finally, a brief example of a topological optimization with the calculated torque contributions as optimization criteria is presented and evaluated.