Energy-based Modeling of AC Motors
  We propose an approach to modeling of AC motors entirely based on analytical mechanics. Symmetry and connection constraints are moreover incorporated in the energy function from which the models are derived. The approach is especially suited to handle magnetic saturation, but also directly recovers the standard unsaturated models of the literature. The theory is illustrated by some experimental data. 
Pascal Combes, Al Kassem Jebai, Fran\c{c}ois Malrait, Philippe Martin,   Pierre Rouchon
math.OC