Alfredo Vagati

Design criteria of high performance synchronous reluctance motors

The main problems related to the design of a synchronous reluctance servomotor are examined. The most suitable rotor structure is identified among different alternatives. A simplified but general algorithm is found for calculating the internal optimized anisotropy ratio. Optimization algorithms are given regarding minimization of the q-axis magnetic flux and maximization of torque for given outside diameter and power dissipation capability. A maximum torque design is illustrated in the general case, practical involvements of this design are pointed out and discussed.<<ETX>>

Evaluation of torque ripple in high performance synchronous reluctance machines

Synchronous reluctance motors with multiple-segment rotor structures are considered. The presence of stator slots is taken into account with respect to torque ripple. An analytical model is presented, based on magnetic interaction between d and q axes, due to stator toothing. The effect of skewing is also considered. Its partial effect on torque ripple reduction due to the rotor anisotropy is shown. A closed expression for the torque is obtained, giving the torque ripple as a function of design parameters. Experimental verification of the proposed model is given based on measurements on prototype motors.<<ETX>>

About the gain choice of flux observer in induction servo-motors

A reduced-order observer is considered for the estimation of the rotor flux in field oriented controlled servomotors. The influence of the observer gain choice on the system performance is analyzed in detail. Sensitivity to thermal variations is taken into account, as well as the influence of the error dynamics. Experimental results are given for a real drive, showing the effects of the different proposed gain choices on the drive behavior.<<ETX>>