• Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
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• 2003.02a
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• pp.266-268
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• 2003

The neon liquefier by using GM cryocooler is designed and in process of manufacturing for the cooling of 100 hp high temperature superconductor (HTS) motor. It was used the principle of thermosyphon that the rotor of the motor is cooled by the latent heat of liquidized neon. The cold-box was designed to minimize heat loss by conduction, convection, radiation. Two heat exchanger were made to liquefy neon by the direct contact of neon gas on the cold head. As a first stage of our project, evaporation apparatus will be setup in the inner field of the cold-box and then the performance of neon liquefier will be test.

• Proceedings of the KIEE Conference
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• 2006.07b
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• pp.865-866
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• 2006

Bearingless Switched Reluctance Motor(SRM) have combined characteristics of SRM and magnetic bearing. Production of radial force for rotor shaft magnetic suspension is explained with differential stator windings. Bearingless SRM is simple structurally because the permanent magnet does not exist and bearing does not take the influence at the environment because it does not exist and has strong torque, and loss of bearing by bearing current has the advantage not to exist. In this paper, a design method of bearingless SRM for suspension power and starting torque is proposed. The design model is implement by maxwell.

• Proceedings of the KIEE Conference
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• 2006.07b
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• pp.673-674
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• 2006

This study investigates the dynamic characteristics of Synchronous Reluctance Motor (SynRM), with segmental rotor structure, using finite element method in which the moving mesh technique is considered. The focus of this paper is the sensorless vector control parameters estimation of SynRM under saturation and iron loss. Comparisons are given with dynamic characteristics of normal single B-H nonlinear solutions and those of proposed FEM & Preisach model of synchronous reluctance motor, respectively.

• Proceedings of the KIEE Conference
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• 2006.07b
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• pp.775-776
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• 2006

Based on the requirement of high power and efficiency in automobile systems, this paper describes an investigation for the optimum design of a permanent magnet reluctance motor(PRM), and then the characteristics of this kind of motor is compared with that of a interior permanent magnet(IPM) motor. The IPM of 4-pole with 6-slot is redesigned into a PRM, which has the same stator and different rotor structure with IPM. Through finite element analysis(FEA) and equivalent circuit method, the PRM has higher salient ratio, higher efficiency at high speed, and lower iron loss compared with IPM.

• 유체기계공업학회:학술대회논문집
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• 2004.12a
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• pp.119-124
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• 2004

In this study, a rotor blade of a Curtis turbine is investigated. Bezier curve is generally used to define the profile of turbine blades. However, this curve gives a feature of global control, which is not proper to a supersonic impulse turbine blade. Thus, a blade design method is developed by using B-spline curve so that local control is possible to obtain an optimized blade section. To design a Curtis turbine blade section systematically, the blade section has been changed by varying three design parameters using central composite design method. Flow analyses have been carried out for the blade sections, and the effects of design parameters are evaluated.

• Proceedings of the KIEE Conference
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• 1999.07a
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• pp.394-396
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• 1999

ADD has developed a special BLDCM(brushless d.c. motor) that has small size and high power density. The model of BLDCM is like that of advanced nation. Design, production and test carried out by ADD and HYOSUNG Corp.. We simulated back EMF of phase, inductance of line and eddy current loss of rotor after we tested the motor at 80 Kw. According to analysis we have established the performance of 100Kw power recently. There are the same results that we designed.

• Proceedings of the KIEE Conference
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• 1999.07a
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• pp.318-320
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• 1999

Electric motor transforms electric power into mechanical power. It is important to increase efficiency of motor to save energy and to decrease operating cost. In this paper, some parameters and losses of high-efficiency induction motor and standard induction motor are measured by blocked-rotor test and no-load test. Operational parameters of high-efficiency induction motor that are compared with those of standard motor.

• Proceedings of the KSME Conference
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• 2004.04a
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• pp.2163-2166
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• 2004

For designing high Tc superconductor proceeding bearing(HTSJB) which is used on a flywheel energy storage system which requests the free of the bearing loss caused by the friction, it is necessary to understand the basic characteristics of the classical superconductor proceeding bearing because the mechanical characteristics of the HTSJB are identified by the magnetic relationships between the permanent magnet(PM) and the high Tc superconductor(HTS). In this paper, using the method, frozen image model, the force problems between the PM and the HTS were solved and then the dynamic characteristics of the rotor inside of the HTSJB can be expected in advance by using the basic characteristics between the PM and the HTS. The coefficient of friction of the HTSJB was measured in the vacuum environment. From the results, the mechanical characteristics of HTSJB can be identified using the numerical models.

• Proceedings of the KSME Conference
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• 2004.04a
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• pp.840-845
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• 2004

In many applications, piezoelectric motor has been used in the areas where excellent controllability, fine position resolution are required or magnetic field noise should be eliminated. However the piezoelectric motor has two major demerits. One is difficulty in maintaining vibration amplitude constantly with temperature rise and wear, and the other is heat generation induced by dielectric and mechanical loss. In this thesis, piezoelectric motor to overcome these problems is proposed. And proposed piezoelectric motor is operated using momentum exchange between bimorph and rotor. To maximize steady state velocity and static torque of proposed motor, the guideline is established using two bimorph models. Then the guideline is partially proved by comparison between simulation and experiment. There was no heat generation in the few hours of experiments.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.49 no.5
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• pp.320-326
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• 2000

The canned motor of 3-phase induction is used for main coolant pump(MCP). The type of motor is canned-motor that stator and rotor are welded by sealed can. So, cooling water flows in the air gap of the canned motor as an independent cycling cooling system from the air gap to yoke of the motor to prevent high temperature of stator can and to lubricate bearing. Heat exchange is occurred between cooling water in the air gap and cooling water from the exterior pump to prevent rising of temperature in the motor. I has to analyze the characteristics of can exactly because the loss and the heat in the can are very important to design MCP. Therefore, thermal analysis is studied considering the effect of eddy-current los induced in the can.