Design and analysis of double‐sided slotless axial‐flux permanent magnet machines with conventional and new stator core

This study proposes a two-phase single-air-gap axial flux permanent magnet (AFPM) motor that offers a trapezoidal back-electromotive force (EMF) waveform to improve the performance of the only-pull drive technique compared with the radial flux PM (RFPM) motor. The only-pull drive technique provides the benefit of allowing the use of thin magnets in the motor without suffering from irreversible demagnetisation. In the proposed motor, the design geometry is primarily considered to achieve the desired trapezoidal shape of back-EMF. The effects of the geometry are explained with the help of air-gap flux density, flux linkage, and the leakage flux. Both the radial flux and the proposed motor adopt the same design concept and hold equal electromagnetic loadings. The profile of back-EMF and the electromagnetic torque driven by the only-pull drive technique are compared with that of RFPM motor with non-trapezoidal back-EMF. Furthermore, the split configuration is proposed for the AFPM motor to reduce torque ripples. The demagnetisation analysis is performed to confirm the operating point of the magnets in a split-AFPM motor. The results reveal that the AF motor is a good candidate for the only-pull drive technique.

Section: Introductionmentioning

confidence: 99%

Electromagnetic design and performance analysis of a two‐phase AFPM BLDC motor for the only‐pull drive technique

Yazdan

Kwon

2018

“…Two-dimensional FEA modelling of AFPM motors can be realised in several manners. Modelling AFPM motors with several 2D linear motors, which can also be called 'linear motor modelling approach (LMMA)', is the only approach used in the literature [13][14][15][16][17][18][19][20]. The 2D FE modelling with LMMA is not investigated thoroughly for such AFPM motors.…”

Section: Introductionmentioning

confidence: 99%

Implementation of different 2D finite element modelling approaches in axial flux permanent magnet disc machines

Güleç

Aydın

2017

Three-dimensional (3D) finite element (FE) modelling of axial flux permanent magnet (AFPM) motors is one of the time-consuming tasks which must be completed before manufacturing the prototype motor. A simple, fast, accurate, and effective numerical modelling approach for such 3D problems would be particularly useful for researchers. This study presents simple and effective 2D FE modelling approaches for AFPM motors with good accuracy with less computational effort. The modelling approaches are based on a number of 2D models or planes with inner rotor, outer rotor, or linear motor topologies. All the 2D planes with either topology are superposed together to represent the real AFPM machine. These approaches are examined in detail with various types of experimentally verified AFPM motors. Results obtained from the proposed modelling approaches are verified with 3D FE analyses and experimental data. The results indicate that the proposed 2D modelling approaches can significantly reduce the computation time with good accuracy as opposed to conventional 3D FE modelling of AFPM motors.

“…It has separately calculated the total iron loss of machine regardless of its interaction with the other performance characteristics. Hekmati et al [20] and Maloberti et al [21] have employed the magnetic equivalent circuits for modelling of AFPM machine, which cannot yield the accurate time waveforms and harmonic contents of various performance characteristics. In some more comprehensive approaches, both the magnets and armature currents have been modelled as equivalent current sheets, yielding the magnetic field distributions based on the solution of Laplacian/quasi-Poissonian field equations in two-dimensional (2D) coordinates [22][23][24][25].…”

Section: Introductionmentioning

confidence: 99%

Detailed analytical method for predicting the steady‐state time variations and entire harmonic contents of principal performance characteristics in a non‐slotted axial flux permanent magnet motor, considering a precise iron loss model

Baghayipour

Darabi

Dastfan

2017

The harmonic contents of principal performance characteristics in an electrical machine are important due to several reasons, especially because they influence the machine acoustic noise generation capability. Therefore, they should be accurately calculated considering the various electromagnetic effects involved in the machine operation. Accordingly, this study proposes a detailed analytical model for predicting the time waveforms and harmonic contents of the principal performance characteristics of a double-sided TORUS-type non-slotted axial flux permanent magnet motor with surface-mounted magnets at steady state under any given loading conditions. The armature-reaction magnetic field and inductances are exactly calculated considering both the effects of coil sides and end windings as well as that of the winding distribution. Most notably, the aggregate iron loss of machine and its influence on armature currents is precisely modelled based on the magnetic field distribution in iron parts. By establishing and solving the differential equation system of motor in the two cases with or without the neutral wire, the armature currents, speed and torque ripples, input/output powers, and copper and iron losses are all achieved with the entire harmonic content and highest accuracy. The comparison of results with those of finite element analysis and real test then validates the model.