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...

Nowadays, magnetic gears (MGs) have become an alternative choice for mechanical gears because of their low maintenance, improved durability, indirect contact between inner and outer rotors, no lubrication, and high efficiency. Generally, although these advantages, MGs suffer from inherent issues, mainly the cogging torque. Therefore, cogging torque mitigation has become an active research area....

Most small wind turbines use permanent magnet (PM) generators. The generators are usually direct-drive (i.e., no gearbox is required). Direct-drive PM generators are characterized by low maintenance and high efficiency. Small wind turbines are usually self-starting and require very simple controls. Cogging torque is an inherent characteristic of PM generators and is caused by the geometry of th...

Smooth motion is critical to some robotic applications such as haptics or those requiring high precision force control. These systems are often direct-drive, so any torque ripple in the motor output must be minimal. Unfortunately, low inherent torque ripple motors are expensive. Low cost brushless DC motors are becoming more prevalent, especially from the hobby RC community. These motors often ...

This paper investigated a 12-slot/11-pole flux switching permanent magnet (FSPM) machine used for electric vehicles (EVs). Five novel rotor teeth shapes are proposed and researched to reduce the cogging torque and torque ripple of the FSPM machine. These rotor teeth shapes are notched teeth, stepped teeth, eccentric teeth, combination of notched and stepped teeth, and combination of notched and...

We present an analytic method to efficiently calculate the torque constant and cogging torque of a hybrid stepping motor. The feature of the proposed method is its computational efficiency in that it is a useful tool for the motor design which is aimed at reducing the level of cogging torque or increasing the torque constant. This method is verified by comparing with the 3D finite element metho...

In this paper, one of the main cogging torque minimization methods, magnet skew, is examined in detail for Axial Flux Permanent Magnet (AFPM) disc motor. Various magnet skewing methods, types, and effects on the machine performance are also investigated using 3D Finite Element Analysis. The results are compared with a reference AFPM motor, and the improvements on cogging torque component are de...

In electric power steering (EPS), spoke type brushless ac (BLAC) motors offer distinct advantages over other electric motor types in terms of torque smoothness, reliability and efficiency. This paper deals with the shape optimization of spoke type BLAC motor, in order to minimization cogging torque. In this paper examines, 3 step skewing rotor angle, optimizing rotor core edge and rotor overlap...

This paper deals with a comprehensive study on reducing cogging torque generated in Brushless DC motor drives (BLDC). In such drives, cogging torque suppression techniques that are practically effective in low speed as well as high speed regions are scarcely found in literature. A well-known skewing technique is adapted in the stator slots to reduce the cogging torque using CAD package Magnet 6...

In this paper the influence of some design parameters on the cogging torque development by a surface mounted permanent magnet motor is investigated. The investigation is focused on the implementation of stator core skewing and dummy slots in the stator teeth and their influence on the cogging torque reduction of the motor. The cogging torque is calculated numerically for the different motor sol...