Bifurcation of equilibria and chaos in permanent-magnet machines

The nonlinear dynamic characteristics of variable-speed permanent-magnet machines in the presence of reluctance variations are considered. A compact representation of the machines´ dynamics is presented and in turn incorporated in investigating the steady-state characteristics of the machines, subject to constant input voltages and load torques. It is shown that the systems under investigation possess multiple equilibria which profoundly affect their global stability and dynamic characteristics. Furthermore, conditions leading to chaotic behavior and Hopf bifurcation are presented and discussed. Finally, numerical simulations are presented to help verify the authors´ results