Real-time adaptive control of the permanent-magnet synchronous motor

The authors develop a fully digital adaptive velocity controller for the permanent-magnet synchronous motor. The critical issues addressed during the development of this controller include discretization and global linearization of the nonlinear motor system, nonlinearities in the inverter, nonminimum phase behavior due to sampling, sampling rate restrictions, robust mechanical state estimation, persistent excitation of the mechanical states, mechanical parameter estimation and validation of these estimates, and unmodeled dynamics. The resulting adaptive controller is implemented in real time using a computer system based on the Motorola 68020 microprocessor. Experimental results demonstrate that the adaptive controller maintains the desired control over velocity in the presence of varying mechanical parameters