• 한국신재생에너지학회:학술대회논문집
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• 2010.11a
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• pp.179.2-179.2
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• 2010

This research has been performed to provide fundamental design aspects of Permanent Magnet Synchronous Generators(PMSGs) for a kilowatt class wind turbine. When it comes to kilowatt class wind turbines, the typical type of generators are Axial Flux Permanent Magnet(AFPM) generators. However, Radial Flux Permanent Magnet(RFPM) generators have been optimally designed to study the output characteristics of a kilowatt class wind turbine in Graduate School of Wind Energy, POSTECH. An existing squirrel-cage rotor has been modified for another newly designed permanent magnet rotor to utilize the commercially existing stator rotor. Electromagnetic analysis utilizing Finite Element Methods tools(ANSYS, MAXWELL 2D) has been applied to analyze the system.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2000.10a
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• pp.547-552
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• 2000

This paper presents a developed squirrel cage induction motor for axial flow In. Nearly all of the induction motors for fan consists of two parts, rotor and stator, and the position of rotor is located inside of stator. This construction restricts the air flow rate, otherwise requires bending duct. But developed squirrel cage induction motor for axial flow fan exchanged the position each other. So, we can reduce the weight and size about 30%, and there are no bending duct to locate the fan motor.

• Journal of Magnetics
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• v.19 no.3
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• pp.309-313
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• 2014

This paper presents an eddy current loss analysis of a Mechanical Fixation (MF) made of 6061 aluminum alloy, which is used for an NS type double-rotor single-stator axial flux permanent magnet machine. The prototype MF made of aluminum alloy shows good mechanical performance, but poor electro-magnetic performance, since the machine's efficiency can decrease because of eddy current loss in the MF. In order to prevent efficiency decrease, a modification of the MF structure is also introduced. Three-dimensional finite element analysis (FEA) is used for magnetic field analysis, and eddy current losses are computed. The analysis results are compared to, and verified by the test results.

• Proceedings of the KSME Conference
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• 2007.05b
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• pp.2518-2523
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• 2007

In this paper, thermo-flow characteristics of an outer-rotor type of a BLDC motor are numerically analyzed using three-dimensional turbulence modeling. In an advance design of BLDC motor, cooling blades and holes are preferred for the enhanced cooling performances. Rotating the blades and holes generates axial air flow passing through stator slots, which cools down stator by forced convection. For the present study, a new design of the BLDC motor has been developed and major design parameters such as the arrangement of cooling holes, the area of cooling holes, and cooling blades and the cooling blade angle, are analyzed for the enhanced convective heat transfer rate. It is found that the convective heat transfer rate of the new BLDC motor model is increased by about 8.1%, compared to that of the reference model.

• Proceedings of the KIEE Conference
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• 2001.07b
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• pp.868-870
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• 2001

Salient pole rotor type single phase SRM(switched reluctance motor) can be use axial direction magnetic flux and radial direction magnetic flux at the same time. Then, it has higher energy density per unit volume and can be lessened the shaft length of motor or exciting magnetic force. Additionally, it's durability is good because it is simple structure and driving device. Prototype of Salient pole rotor type single phase SRM was fabricated by using parameters of three phase SRM and 3D FEM analysis. Also, driving device was fabricated for prototype. Speed and torque characteristic was confirmed through the experiments, and flux linkage, which is important parameter of SRM for generating torque, was measured. The induction emf was calculated by using ideal inductance graph and current graph. Calculated emf and measured emf was compared for confirming loss of prototype in this paper.

• International Journal of Fluid Machinery and Systems
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• v.6 no.1
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• pp.18-24
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• 2013

In order to apply the design method of diagonal flow fan based on axial flow design to the design of radial-outflow type diagonal flow fan which has lower specific speed of 600-700 [$min^{-1}$, $m^3/min$, m], radial-outflow type diagonal flow fan which specific speed was 670 [$min^{-1}$, $m^3/min$, m] was designed by a quasi three-dimensional design method. Experimental investigations were conducted by fan characteristics test, flow surveys by a five-hole probe and a hot wire probe. Fan characteristics test agreed well with the design values. In the flow survey at rotor outlet, the characteristic region was observed. Two flow phenomena are considered as the cause of the characteristic region, one is tip leakage vortex near rotor tip and another is pressure surface separation on the rotor blade.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.6
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• pp.730-737
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• 2018

This paper aims to design of a double stator axial field 12/10 SRM. Conventional and single stator axial field SRMs were reviewed to apply for automotive cooling fan. The axial field SRM has the advantage of shorter flux path, higher torque per volume and lower iron loss. However, there is axial eccentricity in single stator axial field SRM due to one side excitation. Therefore, a double stator type is designed in this paper to reduce the axial eccentricity. And the trapezoidal pole shape of the stator increases the flow of magnetic flux from stator to rotor and the torque region. The torque and efficiency are compared and tested with experiments.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.31 no.9
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• pp.772-779
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• 2007

In this paper, thermo-flow characteristics of an outer-rotor type BLDC motor are numerically analyzed using three-dimensional turbulence modeling. On the rotor of the BLDC motor, cooling blades and cooling holes are existed for the enhanced cooling performances. Rotating the blades and holes generates axial air flow streaming into inner rotor side and passing through stator slots, which cools down stator by forced convection. Operating tests are performed and the numerical temperature fields are found to be in good agreement with experimental results. A new design of the BLDC motor has also been developed and major design parameters such as the arrangement of cooling holes, the area of cooling holes and cooling blades, and the cooling blade angle, are analyzed for the enhanced convective heat transfer rate. It is found that the convective heat transfer rate of the new BLDC motor model is increased by about 8.1%, compared to that of the reference model.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.36 no.9
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• pp.898-906
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• 2008

A tested turbine consists of two stages, and an axial-type and a radial-type turbine are applied to the first and second stage, respectively. The mean diameter of the axial-type turbine rotor is 70 mm, and the outer diameter of the radial-type turbine is 68mm at the inlet. In this experiment, an axial-type turbine, two different radial-type turbines, and three different nozzle flow angles are applied to find the optimal design parameters. To compare the turbine performance, the net specific output torque is evaluated. The test results show that the nozzle flow angle on the first stage is a more important parameter than other design parameters for partially admitted small turbines to obtain high operating torque. For a 3.4% partial admission rate, the net specific output torque is increased by 13% with the addition of a radial-type rotor to the second stage when the turbine operates at $75^{\circ}$ nozzle flow angle.

• Proceedings of the KIEE Conference
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• 2001.04a
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• pp.123-125
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• 2001

Salient pole rotor type single phase SRM(switched reluctance motor) uses the magnetic fluxes of radial and axial direction at the same time. Therefore the output power per unit volumn is very high and shaft length can be shorter than any other types of SRM with same output. Also, It can be manufactured with low cost thanks to simple structure and driving circuit. We already designed and manufactured prototype using the dynamic output equation of general rotating machine but the effect by salient pole structure was not considered. The most optimal design parameters for salient pole rotor type single phase SRM will be selected by comparing and analyzing the results from 3D FEM analysis, experimental values of the torque versus speed characteristics. and the nux linkage of prototype. Results for the former 3D FEM analysis and torque vs. speed characteristics were already obtained. Finally, we will measure the nux linkage of salient pole rotor type single phase SRM.