Dogodkovno osnovano vodenje motorja s trajnimi magneti : doktorska disertacija

slovenian

doktorska dela

2009

Univerza v Mariboru, Fakulteta za elektrotehniko računalništvo in informatiko

The first part of this thesis presents a method for evaluating the torque ripple of a surface mounted permanent magnet synchronous motor due to the mutual and cogging torque. The ripple in mutual torque is caused by non-sinusoidal stator flux linkage distribution which is in direct correlation with the motor back-EMF. A least squares approximation method is applied to estimate the back-EMF harmonic content from experimental data for back-EMF, rotor speed and rotor position. The least squares method is also used to evaluate the cogging torque from a torque disturbance signal which is estimated using a closed-loop observer from the calculated mutual torque and measured rotor speed. The second part of the thesis deals with current control which plays a key role in controller-based design techniques for minimizing the torque ripple. The proposed event driven current control present an alternative to the conventional hysteresis control which uses three independent controllers, one for each phase. As distinguished from the conventional hysteresis control the even driven control introduces additional information about voltage sector. The comparison between this two control techniques is given regarding to different performance criteria like current error, number of inverter switching's and deviation from the reference current-speed motor characteristics. The discussed current control is also applied in the torque ripple minimization scheme where a speed controller in combination with current feedforward loop is used as design techniques for minimizing the torque ripple. Described concepts are verified with experimental results.

07.08.2023