Nonlinear control of wound-rotor synchronous-motor

The problem of controlling wound rotor synchronous motors is considered. First, a nonlinear model of the controlled motor is developed in the Park (d, q)-coordinates. Then, a nonlinear regulator is designed using the backstepping technique. The resulting closed-loop is proved to be asymptotically stable and the motor speed is shown to achieve its reference trajectory. These theoretical results are confirmed by simulations which, in addition, show that the proposed regulator has an important rejection capability with respect to load torque changes