Real-time position control in permanent magnet synchronous machine drives

A challenging problem in permanent magnet synchronous machine (PMSM) drives is position control in the presence of unknown disturbances. This paper proposes a low-computational-complexity cascade control structure for position control in PMSM drives. Model-Based Design is used to create an optimal controller in the error space of the outer loop of the cascade control structure. A state and disturbance observer is employed to estimate the load torque of the drive. A PI-based control algorithm is used in the inner current control loop. This paper presents real-time simulation results of the cascade control and PMSM drive model using a Speedgoat Performance real-time target machine. Finally, it compares those results to results obtained by using a traditional PI control approach.