• Proceedings of the KIEE Conference
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• 2001.07b
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• pp.974-976
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• 2001

This paper presents a method to reduce commutation torque ripples occurred during commutation in brushless do motor drives using a single DC-link current sensor. In brushless dc motor drives with a single dc current sensor instead of 3-phase line current sensors, it is noted that dc-link current sensor cannot give any information corresponding to the motor currents during line current commutation intervals. A new technique to resolve such a problem is dealt with based on a deadbeat current control in which motor armature voltage command is computed from a dc-link current reference, an actual current and counter emf voltage. The simulation results show that the proposed method reduces the torque ripple significantly.

• Proceedings of the KIEE Conference
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• 2001.07b
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• pp.834-836
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• 2001

This paper deals with analysis for demagnetization characteristic of a ferrite magnet line start motor using FEM. Maximum start and clock currents are calculated by transient state voltage and dynamic equation, and then, these currents are applied to FE analysis. The characteristics of motor according to partial demagnetization are analyzed from FE analytic results, and rotor shape is designed for improvement of demagnetization characteristic.

• Proceedings of the KIEE Conference
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• 2001.07b
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• pp.877-879
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• 2001

The switched reluctance motor (SRM) has a simple motor construction with no rotor windings. It also has simple concentrated windings on the stator windings. Thus it is expected to be a lower cost machine to manufacture than other motors. This paper has computed an optimal parameters asking for SRM drives using by PC-SRD that was programmed by T. J. E. Miller/M. Mcgilp. According to advanced angle and dwell angle, the output, efficiency, currents and torque were computed. The experiments with 8/6 SRM have tested.

• Proceedings of the KIEE Conference
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• 2001.07b
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• pp.1160-1164
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• 2001

The input voltage of linear Induction motors(LIMs) is involved with the time harmonics because most LIM is driven by inverter. Therefore the equivalent circuit for an inverter-fed LIM has to be modifided to represent every harmonic present in supply voltage. This paper describes that the dynamic characteristic can be used effectively for analyzing the characteristics of a linear induction motor position and speed control.

• Proceedings of the KIEE Conference
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• 2001.07b
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• pp.1169-1171
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• 2001

Synchronous reluctance motors(SynRM) for the application such as an electric vehicle, compressor drives of air conditioner and machine tool spindle drives require a wide field-weakening speed range. In order to improve the efficiency performance in such applications, this paper has examined the loss and the efficiency characteristics of SynRM mainly in the field-weakening speed region over the base speed. The control strategy in order to offer a efficiency optimization operation is shown and the copper and iron losses driven the equivalent circuit model of the machine is minimized. The usefulness of the proposed efficiency optimization control is verified through the SynRM durve system.

• Proceedings of the KIEE Conference
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• 2001.07b
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• pp.933-935
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• 2001

This paper presents a calculating method for inductance of the Switched Reluctance Motor(SRM) for torque characteristics and driving by analytical model. The approaches for calculating inductance have taken vary from detailed finite element analysis(FEA) and Fitting method in magnetization curves using complex nonlinear magnetic circuit models. But those methods have not satisfactory approach for machine performance calculations, because of having a long time and remodeling for analyses, therefore thus an alternative approach is required. So it is suggested simply calculating method of the inductance based on designed data of machinery by analytical model in unaligned and aligned rotor. In order to prove the calculating, there are compare with analytical FEM, direct measurement, this method, and simulation. The compared result is shown to obtain good accuracy.

• Proceedings of the KIEE Conference
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• 2001.07b
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• pp.813-815
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• 2001

Permanent magnet DC motor is widely used in electrical tools, automotive manufacturing systems, electric vehicles, OA system drives, aircrafts and home appliances PM motors are suited for such an application, since they can be designed for high torque-to-speed ratio and efficiency. This paper deals with permanent magnet DC motor which is used in an electrical wheelchair. The motor has 6 PMs and 25 slots, and is coupled to the wheel with gears. In this study, motor design was carried out using finite element method. This paper discusses the design and construction of the prototype system and reports experimental results achieved from laboratory tests.

• Proceedings of the KIEE Conference
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• 1999.11c
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• pp.549-551
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• 1999

Recently, Several type of motors are used more widely in Fan system because of their low cost and high reliability. Therefore, the importance of fault detection and isolation of fan system significantly increases. The motor is a important factor bring out the fan system fault. So the problem of a fault detection for motor based on a parameter identification will be considered in this paper. After an introduction into fault detection with parameter estimation, a mathematical model for motor with special emphasis on motor itself. In the fault detection system, current and motor speed are used as parameter. Finally, simulation results are used to demonstrate the efficiency of the fault detection system.

• Proceedings of the KIEE Conference
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• 2001.07b
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• pp.849-851
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• 2001

This paper presents experimental method of parameter measurement and starting characteristics of 3 phase induction motor. Equivalent circuit parameters measured by DC test, the blocked rotor test, and no load test were used as the input data for computer simulation. Starting characteristics, such as starting current and torque were analyzed through computer simulation by Matlab, and the simulation results were compared with experiment using strain gauge attached on motor shaft. We conform that experimental results are very similar to that of simulation.

• Proceedings of the KIEE Conference
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• 1998.11c
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• pp.749-751
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• 1998

In this study, the wind-mill type ultrasonic motor was fabricated, and then revolution and temperature characteristics of the ultrasonic motor were measured. Brass metal was pressed with umbrella-type using metal mold, then slot of 4 kind was processed in each of thickness. Among sixteen's ultrasonic motors, heat loss on applied voltage was much at stator of the highest resonant point, but heat loss on applied voltage was almost neglected at the lowest resonant point of stator. The thickener thickness of elastic body, revolution speed was decreased. The more slot of elastic body, revolution speed was increased. Applied voltage was changed from $10V_{max}$ to $100V_{max}$. When applied voltage was under $20V_{max}$, ultrasonic motor was not rotated. When applied voltage was over $90V_{max}$, revolution of ultrasonic motor was saturated. Maximum revolution speed was 510[rpm].