• Proceedings of the KIPE Conference
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• 2003.07b
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• pp.828-831
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• 2003

This paper presents a novel design technique and characteristic analysis of Magnet for dual air-gap axial-flux type permanent-magnet synchronous generator. The process of magnet design is applied to the motor design and steady state analysis considering output voltage waveforms and magnetic flux waveforms. Design and construction of an axial-flux permanent-magnet generator with power output at 60 [Hz], 300[r/min] is introduced. Finite-element (FE) method is applied to analyze magnet shape characteristics. The results of FE analysis show generator is feasible for use with dual air-gap axial-flux permanent- magnet synchronous generator.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.2
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• pp.223-230
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• 2012

This paper deals with an design of axial flux electric machine which is a key element for a compact size in a portable and manual generator system. It is expected that the generator system with an axial flux electric machine is more light and has higher efficiency than other types of generator systems. And it is used the soft magnetic composite core instead of silicon steel core in the axial flux electric machine for more compact size. The weight and efficiency of the generator system are the main keys to select the value of design variables. In this paper, the overall design process to meet the design goals, and the design results are presented with experiment results.

• Journal of Magnetics
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• v.19 no.3
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• pp.273-281
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• 2014

This paper presents an innovative design for a low-speed, direct-drive, axial-flux permanent-magnet (AFPM) generator with a coreless stator and rotor that is intended for application to small wind turbine power generation systems. The performance of the generator is evaluated and optimized by means of comprehensive 3D electromagnetic finite element analysis. The main focus of this study is to improve the power output and efficiency of wind power generation by investigating the electromagnetic and structural features of a coreless AFPM generator. The design is validated by comparing the performance achieved with a prototype. The results of our comparison demonstrate that the proposed generator has a number of advantages such as a simpler structure, higher efficiency over a wide range of operating speeds, higher energy yield, lighter weight and better power utilization than conventional machines. It would be possible to manufacture low-cost, axial-flux permanent-magnet generators by further developing the proposed design.

• Proceedings of the KIEE Conference
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• 2003.07b
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• pp.1063-1066
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• 2003

This paper presents the design and characteristics analysis of axial-flux permanent-magnet (PM) synchronous generator of two air-gap. Dual axial-flux type PM synchronous generator commonly appears in applications where the generator axial dimension is more limited than the radial dimension. The strengths of dual axial-flux generator include ; (1) by employing two air-gaps, the rotor-stator attractive forces are balanced and no net axial or thrust load appeals on the generator hearings ; (2) heat produced by the stator windings appears on the outside of the generator, making it relatively easy to remove, and so on. In this paper, the simple magnetic equivalent circuit approach is used for initial design iteration, and the finite-element method is applied to analyze the detailed characteristics. The test results of driving characteristics are presented as well. The results are very similar to predicted performance of design.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.12
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• pp.1820-1827
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• 2012

This paper is to present a new method of cogging torque reduction for axial flux PM machines of multiple rotor surface mounted magnets. In order to start softly and to run a power generator even the case of weak wind power, reduction of cogging torque is one of the most important issues for a small wind turbine, Cogging torque is an inherent characteristic of PM machines and is caused by the geometry shape of the machine. Several methods have been already applied for reducing the cogging torque of conventional radial flux PM machines. Even though some of these techniques can be also applied to axial flux machines, manufacturing cost is especially higher due to the unique construction of the axial flux machine stator. Consequently, a simpler and low cost method is proposed to apply on axial flux PM machines. This new method is actually applied to a generator of 1.0kW, 16-poles axial flux surface magnet disc type machine with double-rotor-single-stator for small wind turbine. Design optimization of the adjacent magnet pole-arc which results in minimum cogging torque as well as assessment of the effect on the maximum available torque using 3D Finite Element Analysis (FEA) is investigated in this design. Although the design improvement is intended for small wind turbines, it is also applicable to larger wind turbines.

• Proceedings of the KIPE Conference
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• 2002.11a
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• pp.78-81
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• 2002

The paper discuses characteristics of an axial-flux permanent-magnet generator for a gearless wind energy system which aims to be satisfied with variable operating conditions. Design and construction of an axial-flux permanent- magnet generator with power output at 60[Hz], 300[r/min] for wind energy system is introduced. Finite-element method (FEM) is applied to analyze generator performance at variable load. The results of FE analysis show this generator Is feasible for use with a wind turbine.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.1071-1072
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• 2011

The axial flux machine has higher power density than conventional radial flux machine, so it is widely applied to various industrial area, for instance, low speed wind power generator. For the conventional radial flux machine, 2D finite element method (FEM) is generally applied, but axial flux machine has to employ 3D FEM with long analysis time due to its own structural characteristic. This paper deals with the performance comparison of axial flux machine according to volume.

• Proceedings of the KIEE Conference
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• 2001.04a
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• pp.455-458
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• 2001

This paper presents an axial flux permanent magnet synchronous generator with a high power-to-weight ratio, dedicated for small-scale gearless wind power generation plants. For this purpose, a specific design is necessary to meet the imposed requirements. In this paper the design technique for the specifications is presented. The aim of the paper is also to discuss some of the first obtained test results and the involved demagnetizing problem (i.e. short-circuit).

• Journal of Electrical Engineering and Technology
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• v.7 no.1
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• pp.69-74
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• 2012

This paper presents a distributed winding type axial flux permanent magnet synchronous generator (AFPMSG) with reduced the total harmonic distortion (THD), suitable for wind turbine generation systems. Although the THD of the proposed distributed winding type is more reduced than the concentrated winding type, the unbalance of the phase back EMF occurs. To improve the unbalance of the phase back EMF and the output power of the distributed winding type AFPMSG, the Kriging based on the latin hypercube sampling (LHS) is utilized. Finally, these optimization results are confirmed by experimental results. As a result, the unbalance of the phase back EMF and the output power of the distributed winding type AFPMSG were improved while maintaining the total harmonic distortion (THD) and the average phase back EMF.

• Journal of Magnetics
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• v.21 no.4
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• pp.577-585
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• 2016

In this paper, model of the axial-flux permanent magnet synchronous generator (AFPMSG) having arc-shaped trapezoidal permanent magnets (PM) is presented. The proposed model reduces the cogging torque and torque ripple, at the expense of lowering the average output torque. Optimization of the proposed model is performed by considering the asymmetric overhang configuration of the PMs, as to make the output torque of the proposed model competitive with the conventional model. The time stepped 3D finite element analysis (FEA) is performed for the comparative analysis. It is demonstrated that the torque ripple of the optimized model is highly reduced as well as average output torque is increased.