• Proceedings of the KSR Conference
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• 2011.05a
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• pp.1092-1096
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• 2011

The "standard regulation" of the vehicles from "urban transit law" are being adopted to electric multiple unit in domestic. In the standard regulation, there are two types for EMU. One is heavy EMU for Seoul. The other is large EMU for Pusan, Daegu, Gwangju, Daejeon, Incheon. Korea Railroad Research Institute, with the assistance of the Ministry of Land, Transport and Maritime Affairs, "advanced EMU development project" are progressed, and 6th year started at September, one unit to six cars is completed. Now "urban transit vehicle performance tests are on the current progress. The main characteristics of AUTS(Advanced Urban Transit System) are as follows. One inverter control one motor, DDM(Dircet Drive Motor), no driving gear, plug door and steps, mounting and maintenance costs down, passenger convenience improvement. This paper describes the key features the next generation EMU, and performance test results, and the commercial success method of national R&D business.

• Proceedings of the KIEE Conference
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• 1998.11b
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• pp.448-450
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• 1998

Global competition of automotive market and affordable prices of electronic components become the major reason that automotive industries rapidly employ a large number of electric and electronic systems to improve vehicle performance and to meet various regulations such as emission, fuel efficiency, and safety. Especially, the provision of a motor-driven steering column (MDSC) for luxury vehicle is getting popular for drivers' convenience. In this study, an MDSC is developed, which provides several intelligent features such as the manual operation for tilting and telescoping the steering wheel, and the save/recall operation for three different steering wheel positions. In addition, the fault detection algorithm is developed.

• Proceedings of the KIEE Conference
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• 1996.07b
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• pp.1222-1224
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• 1996

The Hong Ik Direct Drive Arm(HIDDA) is a SCARA typed direct drive manipulator with two degrees-of-freedom(DOF) using the direct drive motor of the NSK company. The direct NSK motors are used to give a large torque directly to the link, to reduce the modeling errors from the gears and chains. But, since the nonlinear coupling torques are transferred to the motor shaft without any reduction, we must consider a dynamic control algorithm. In this paper, we designed a robot controller for the HIDDA using a TMS320C31, which has the highest performance among the third DSP chips in the TI company. And we developed the integrated environment software of the robot management system to give the users an easy way of programming, running and simulation of the robot on the PC.

• Journal of Power Electronics
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• v.17 no.5
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• pp.1203-1210
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• 2017

This paper presents an improved switching selection method for the direct torque control (DTC) of five-phase induction motors (IMs). The proposed method is conducted using optimal switching selection. A five-phase inverter has 32 voltage vectors which are divided into 30 nonzero voltage vectors and two zero voltage vectors. The magnitudes of the voltage vectors consist of large, medium, and small voltage vectors. In addition, these vectors are related to the torque response and torque ripple. When a large voltage vector is selected in a drive system, the torque response time decreases with an increased torque ripple. On the other hand, when a small voltage vector is selected, the torque response time and torque ripple increase. As a result, this paper proposes an optimal voltage vector selection method for improved DTC of a five-phase induction machine depending on the situation. Simulation and experimental results verify the effectiveness of the proposed control algorithm.

• Journal of Power Electronics
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• v.16 no.4
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• pp.1355-1366
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• 2016

In the present paper, a speed control algorithm with fast response characteristics is proposed to reduce the shift shock of medium/large-sized electric vehicles equipped with a two-speed AMT. Shift shocks, which are closely related with to the vehicles' ride comfort, occur due to the difference between the speed of the motor shaft and the load shaft when the gear is engaged. The proposed speed control method for shift shock reduction can quickly synchronize speeds occurring due to differences in the gear ratios during speed shifts in AMT systems by speed command feed-forward compensation and a state feedback controller. As a result, efficient shift results without any shift shock can be obtained. The proposed speed control method was applied to a 9 m- long medium- sized electric bus to demonstrate the validity through a simulated analysis and experiments.

• Journal of Power Electronics
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• v.16 no.3
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• pp.936-945
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• 2016

Large magnitude common-mode voltage (CMV) and its variation dv/dt have an adverse effect on motor drives that leads to early winding failure and bearing deterioration. For matrix converters, the switch states that connect each output line to a different input phase result in the lowest CMV among all of the valid switch states. To reduce the output CMV for matrix converters, this paper presents a new space vector modulation (SVM) strategy by utilizing these switch states. By this mean, the peak value and the root mean square of the CMV are dramatically decreased. In comparison with the conventional SVM methods this strategy has a similar computation overhead. Experiment results are shown to validate the effectiveness of the proposed modulation method.

• Proceedings of the KIEE Conference
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• 1999.07f
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• pp.2526-2528
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• 1999

Parameters of equivalent circuit of IPMSM are varied according to current magnitude and current phase angle. Especially, Parameter variation of IPMSM for an electric vehicle(EV) is critical. Because current magnitude is very large. and current phase angle range also is wide. So, variation characteristics of $L_d$ and $L_q$ of the IPMSM are analyzed and verified through experiments. And then new parameter estimator of $L_d$ and $L_q$ that is constructed by neural network technique is suggested Using numerical method, the advanced characteristics of current controller of vector control algorithm is verified.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.1258-1259
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• 2008

In this paper, the variable tendency of the piezoelectric constant and resonance characteristics of the piezoelectric ceramics due to the electric field is studied. The practical application of piezoelectric ceramics is not only applied in field of small signal. For example, in case of an ultrasonic motor, 120 ${\sim}$ 130Vrms of driving voltage is needed. Therefore, to examine the characteristics of piezoelectric ceramics in large signal contributes to reducing the susceptibility to the multifarious application and securing the ease of the production of control circuit. These contributions may be connected to the expansion of industrial application. We fabricated disk-type piezoelectric ceramic samples by using conventional method and measured the resonance characteristics of these samples under from low to high voltage driving conditions. According to increasing the value of the input voltage, we measured the resonance frequency of the piezoelectric ceramic, and inquired into the cause of these phenomena.

• Transactions of the Korean Society of Automotive Engineers
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• v.19 no.6
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• pp.76-81
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• 2011

Fossil fuel, the energy source of internal combustion engine automobiles, is limited in resource and has caused environmental issues for decades. Accordingly, automobile manufacturers from many countries around the world are developing or producing eco-friendly vehicles that utilize alternative sources of energy. These vehicles are equipped with many electronic and electrical components which operate on high voltage and/or large current that were not used in conventional combustion engine automobiles. In this paper, in order to analyze the electro-magnetic interference noise, electric vehicles and fuel cell electric vehicles are tested under the guidelines of KMVSS (Korean Motor Vehicle Safety Standards) as well as under test modes that are not stipulated under the guidelines.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.1
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• pp.57-65
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• 2007

Along with the development of power electronics and magnetic materials, permanent magnet (PM) brushless direct current (BLDC) motors are now widely used in many fields of modern industry BLDC motors have many advantages such as high efficiency, large peak torque, easy control of speed, and reliable working characteristics. However, Compared with the other electric motors without a PM, BLDC motors with a PM have inherent cogging torque. It is often a principle source of vibration, noise and difficulty of control in BLDC motors. Cogging torque which is produced by the interaction of the rotor magnetic flux and angular variation in the stator magnetic reluctance can be reduced by sinusoidal air-gap flux density waveform due to reduction of variation of magnetic reluctance. Therefore, this paper will present a design method of magnetizing system for reduction of cogging torque and low manufacturing cost of BLDC motor with isotropic bonded neodynium-iron-boron (Nd-Fe-B) magnets in ring type by sinusoidal air-gap flux density distribution. An analytical technique of magnetization makes use of two-dimensional finite element method (2-D FEM) and Preisach model that expresses the hysteresis phenomenon of magnetic materials in order for accurate calculation. In addition, For optimum design of magnetizing fixture, Factorial design which is one of the design of experiments (DOE) is used.