Mehmet Gulec

Reduction of Cogging Torque in Double-Rotor Axial-Flux Permanent-Magnet Disk Motors: A Review of Cost-Effective Magnet-Skewing Techniques With Experimental Verification

Minimizing cogging torque in designing axial-flux permanent-magnet (AFPM) motors is one of the main issues which must be considered during the design process. This paper presents several cost-effective magnet-skewing techniques to minimize cogging torque components in double-rotor AFPM motors. Rotor-side cogging torque minimization methods are examined in detail with major focus on magnet-skewing approach, and several cost-effective alternative skewing techniques are proposed. A detailed comparison of magnet-skewing approaches is provided. A prototype AFPM motor with different rotor structures is built based on the analyses. Analyses are then validated with experimental results, and the influence of cogging torque component on torque quality of AFPM motors is explored. The results confirm that the proposed magnet-skewing approaches can significantly reduce the cogging component as opposed to reference AFPM motor with unskewed magnets and help to improve the torque quality of the disk motors.

Design and validation of a 24-pole coreless axial flux permanent magnet motor for a solar powered vehicle

This paper is about modelling, design and validation of a 24 pole coreless axial flux permanent magnet motor for solar powered vehicle applications. A double-rotor coreless axial flux surface mounted permanent magnet motor is investigated in this study. Coreless axial flux permanent magnet (AFPM) motor is analytically modelled by magnetic equivalent circuit, and the design is finalized by 3-D finite element analyses (FEA). Prototype of coreless AFPM motor is built to validate simulation results. No-load and on-load performance tests for the built motor are performed. Back EMF and initial on-load results obtained from FEA and test set-up are in good agreement.

A New Coreless Axial Flux Interior Permanent Magnet Synchronous Motor With Sinusoidal Rotor Segments

Axial flux permanent magnet (AFPM) motors are frequently used in many applications. Axial gap coreless motors with surface-mounted magnets are the most noteworthy ones due to their potentially higher efficiency and smaller axial length. In this paper, a new spoke-type AFPM coreless disk motor with dual rotor and single stator is proposed with sinusoidal rotor segments. This new disk-type motor is an interior PM (IPM) motor with spoke-type rotor and variable air gap to obtain sinusoidal back Electro-Motive Force waveform. It is shown that it is possible to increase the air-gap flux density in the proposed new coreless AF-IPM motor and increase the torque output compared with the conventional surface-mounted AFPM motors.

Influence of magnet grouping in reduction of cogging torque for a slotted double-rotor axial-flux PM motor

This study is about minimization of cogging torque in an axial flux permanent magnet (AFPM) motor with integer number of slots per pole per phase with the focus on pole shifting or grouping. The analyses of cogging torque component are presented and compared with other cogging torque minimization methods and a reference AFPM motor with standard fan-shaped magnets. It is shown that magnet grouping is an effective method to eliminate cogging torque component in AFPM motors.

Design and control of an 8-slot radial flux magnetic bearing

This work presents the design and control of an 8-slot radial flux magnetic bearing. Design of magnetic bearing is carried out with coupled magnetic equivalent circuit model and finite element analysis (FEA). The magnetic design is verified with 2D FEA and good agreement between the two is obtained. Designed magnetic bearing is assembled into a system and fuzzy logic control is applied to the magnetic bearings to adjust the currents in order to balance the system shaft. The control is performed at the equilibrium position under different disturbances and detailed information about the working space of the designed magnetic bearings is provided.

Modelling and analysis of a new axial flux permanent magnet biased eddy current brake

This paper describes a novel axial flux permanent magnet (AFPM) biased eddy current brake (ECB). Structure, principles of operation and benefits of the proposed AFPM-ECB compared to conventional ECBs are presented. A non-linear magnetic equivalent circuit based design model is generated for the proposed AFPM-ECB. Detailed 3D finite element models (FEM) are created to see more accurate breaking torque capability of the system. The work is also compared with a conventional ECB which was built and tested. It was shown that more torque capability and faster response time can be achieved with the proposed AFPM-ECB.