Torque calculation of electrical machines based on distributions of surface forces along the stator boundary as well as volume forces inside conducting and iron domains

The generated mechanical torque of an electrical machine can be determined in several ways from electromagnetic field quantities, e.g. with the virtual work or the Maxwell stress tensor methods. The difficulty of allocating local acting force densities is skipped with both methods. Instead, the performed investigation proposes a novel formulation for the mechanical torque calculation which is based on local volume force densities in current carrying conductors and iron domains as well as distributions of surface force densities along stator boundaries.