Optimal control and variable structure combination using a permanent-magnet synchronous motor

Optimal control theory is applied to design of the position and speed controllers for an AC servomotor drive using a permanent-magnet synchronous motor. In the proposed scheme, stator currents are controlled by an inner loop based on the principle of predictive control. Performances and robustness of the outer loops are examined and the structure variable is added to it to provide better performance in a wide range. The proposed scheme has been implemented on an experimental 1.5 kW servomotor drive using a floating-point DSP (TMS320C30). Experimental results are presented and discussed