Cogging Torque Estimation of Permanent Magnet Motors Resulting from Magnetic Anisotropy of Non-oriented Electrical Steel Sheets

Observer-Based Rejection of Cogging Torque Disturbance for Permanent Magnet Motors

In order to prove the speed regulation for permanent magnet motor systems, a control method is proposed to reject the disturbance by cogging torque, which arises from the interaction of the rotor magnets with the steel teeth on the stator. Toward this aim, we present a state observer with an internal model which has harmonics of sinusoids, and it follows from the proposed observer that the info...

Direct Torque Control of Permanent Magnet Synchronous Motors

Cogging Torque Minimization of Surface-Mounted Permanent Magnet Synchronous Machines Using Hybrid Magnet Shapes

This paper deals with the magnet pole shape design for the minimization of cogging torque in permanent magnet synchronous machines (PMSM). New shapes of permanent magnet are proposed. The magnet shape is modeled analytically by a set of stacked and well dimensioned layers relatively to the height and opening angle. The final shape of magnet is configured by using three models in view of obtaini...

Cogging Torque Reduction of Sandwiched Stator Axial Flux Permanent Magnet Brushless DC Motor using Magnet Notching Technique

Cogging torque reduction of axial flux permanent magnet brushless dc (PMBLDC) motor is an important issue which demands attention of machine designers during design process. This paper presents magnet notching technique to reduce cogging torque of axial flux PMBLDC motor designed for electric vehicle application. Reference axial flux PMBLDC motor of 250 W, 150 rpm is designed with 48 stator slo...

Cogging Torque Control in Brushless Dc Motors

During the past five years, cogging torque in HDD spindle motors has decreased drastically as designers and manufacturers have developed a better understanding of the cogging phenomenon. This paper examines various methodologies of cogging torque reduction. Timing techniques such as dead zones and tooth notching, smoothing techniques such as sinusoidal magnetization, and geometric techniques su...