• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.77-78
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• 2006

Post industrial technologies have improved human standard of living, however, a host of negative environmental consequences from the unlimited industrial appetite have posed serious global challenges. Remanufacturing is an industrial manufacturing process that is to restore old products to perform like a new and to save energy, natural resources, landfill space and to reduce air pollution by less re-smelting. By extending product life cycle, remanufacturing gives us enormous opportunities for sustainable development of our society. This paper introduces current state of the art and future perspective in the field of automotive remanufacturing focusing on alternator and start motor. The results could be used as a basic information for further remanufacturing applications in Korea.

• Journal of Electrical Engineering and Technology
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• v.1 no.4
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• pp.490-495
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• 2006

In this research, the design procedure and the design method of a single-phase line-start permanent magnet motor (LSPM) are proposed. In the design procedure, the permanent magnet is designed first and the windings and capacitors are designed later. As well, the points of design of each design parameter are explained. In the design of the single-phase LSPM, the equivalent circuit method is combined with the finite element method (FEM) because it has a shorter analysis time than FEM. The 400 watts single-phase LSPM is designed and manufactured. The characteristics of the manufactured single-phase LSPM are analyzed and experimented. From the analysis result and the experiment result, it is verified that the design procedure and the design method of the single-phase LSPM is valid.

• Proceedings of the KIEE Conference
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• 2006.07b
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• pp.763-764
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• 2006

In this paper, optimized model was designed for the starting characteristic of the Single-Phase Line-Start Permanent Magnet Synchronous Motor by using the Design of Experiment. A field pole angle, thickness and distance from center axis of permanent magnet were selected as design factor. We executed the transient state characteristic analysis of 8 test models. The transient state characteristic analysis was executed by using the 2 dimensional Finite Element Method and the Time Difference Method. We checked the fact that the selected design factor affected starting characteristic of the Line-Start Permanent Magnet Synchronous Motor. Depend on this result we found the optimized design point by using the response optimization.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.55 no.3
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• pp.131-137
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• 2006

This paper deals with the conductor bar design to improve starting stability of line start synchronous reluctance motor(LSSynRM). As design variables, the number and the shape of conductor bars of rotor are chosen. The starting characteristics are calculated by finite element method(FEM) and the conductor bars are designed to improve the starting torque according to the initial starting rotor position. Finally, the starting characteristic of the designed model are compared with that of the initial model.

• Journal of Electrical Engineering and Technology
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• v.9 no.2
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• pp.508-513
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• 2014

Heavy load start but light load operation is a common case in practical drive applications. When an induction motor is employed for such applications, its rated power is usually chosen according to the heavy load start. Then, during light load operation, its efficiency and power factor are low. To solve this problem, it is proposed to adjust the motor windings from the startup to the normal operation conditions. In this paper, arrangement of the adjustable windings is introduced, air gap field with different windings is investigated, and steady state operation performance under various loads is examined. It can be seen that by using proper winding arrangement both startup and operation performances are satisfactory.

• Journal of IKEEE
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• v.22 no.2
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• pp.258-265
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• 2018

This paper proposes an algorithm for reducing the starting current when the single-phase induction motor starts and analyzes its operation. Generally, the single-phase induction motors require several starters to generate the starting torque due to their structural characteristics. In this paper, a capacitor-start / capacitor-run method of the single-phase induction motor is basically adopted. This conventional method is efficient and has a large starting torque, but it generates about 5 ~ 6 times of inrush current at startup. As a result, the freezer starting device and peripheral devices are damaged and life time may be reduced. To reduce the inrush current, the current control algorithm based on the virtual dq model is presented to control the starting current. In addition, it validates the proposed algorithm through experiments to smooth transit from start-up operation to the rated operating region.

• Transactions of the Korean Society of Automotive Engineers
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• v.8 no.1
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• pp.32-39
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• 2000

To optimize the cold start process of a 4-stroke, 8 cylinder Diesel engine, a dynamic simulation model from cranking to idle speed is developed. Physically-based first order starter motor dynamics are used to model the performance of starting process which is very complex. These equations are solved using numerical schemes(Petzold-Gear BDF method) to describe the starting process of diesel engine and to study the effects of starting parameters. The validity of this model is examined by start test. This model can be served as a tool for computer aided control systems design to improve cold improve cold start performance.

• Journal of Hydrogen and New Energy
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• v.20 no.3
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• pp.224-231
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• 2009

The improvement of cold start capability is one of the most challenging tasks to be solved for commercialization of fuel cell vehicle. In this study, cold start test and ice blocking test(IBT) of fuel cell stack were carried out under various operating conditions. This fuel cell stack can be thawed from -20$^{\circ}$C within 25s and the voltage change was found to be comprised of 4 steps; the first step is the voltage decrease by overpotential, the second step is the voltage increase by the cell temperature increase, the third step is the voltage decrease by ice blocking, and the last step is the voltage increase by thawing. Bootstrap startup was failed after shutdown at temperature under 40$^{\circ}$C because of much condensed water in the fuel cell. Quantitative estimation of cold start capability have been demonstrated by ice blocking test(IBT). In the results, it was found that cold start capability was improved double every 10$^{\circ}$C from 30$^{\circ}$C to 65$^{\circ}$C and enhanced by 30% at the condition of SR 3/4 compared to SR 1.5/2.0 and enhanced by 20% with dry purge condition compared to with RH 50% purge condition.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.52 no.8
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• pp.373-380
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• 2003

This paper consists of a study in post-assembly magnetization of LSPM (Line Start Permanent Magnet Motor). Recently, LSPM is noted as an alternative to the induction motor because it offers a very high efficiency and unity power factor, And it is necessary for permanent magnets to be magnetized by means of post-assembly magnetization in LSPMS because of the manufacturing cost involved. The manufacturing process is also simpler in post-assembly magnetization than in pre-assembly magnetization. Generally, permanent magnet motors are magnetized by their own stator coil or by magnetizing fixtures. However, the permanent magnet in a LSPM is scarcely magnetized by using them because of the eddy current of the rotor bar. Hence, it is necessary to design a magnetizing fixture that overcomes this problem. In this paper, the author analyses the post-assembly magnetization of a LSPM and proposes a method for designing the magnetizing fixture. The method that the author proposes is to make the number of coil turns greater in order to reduce the effect of the eddy current of the rotor bars.

• Proceedings of the KIEE Conference
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• 2005.04a
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• pp.12-14
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• 2005

This study investigates the characteristic analysis of Line-start Permanent Magnet Synchronous Motor considering skew effect. The effects of the skew on machine characteristic are analyzed by using direct co-simulation of Matlab Simulink and Flux2D. Validity of analysis method is confirmed by the analysis result of Non-skew Model.