Nonlinear multirate adaptive control of a synchronous motor

The nonlinear adaptive digital control of a synchronous motor using a nonlinear modelization in the (d, q) frame is discussed. It is shown that a multirate control strategy provides an appropriate framework for achieving speed regulation, thereby ensuring the stability of the whole control system. When parametric uncertainties on the resistance of the stator windings and the load torque occur, this scheme is completed with an adaptation law deduced from hyperstability concepts. This results in the asymptotic satisfaction of the control objectives at the sample instants. Simulation results are presented