• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.7
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• pp.971-977
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• 2015

The electric propulsion system requires more reliability and safety than the conventional propulsion system because any sudden changes of electric system would bring tremendous effects on the ship's safety and propulsion. So it is very important to consider the potential transient effects. This paper discusses one of the worst electric accident. That is, one or two of generators are out of service in normal seagoing condition. And the appropriate measures are simulated in order to prevent the frequency decline that can bring the other generator's tripping. In addition, the relation between the transient effects and the major factors(inertia of generator/motors, governor's drooping characteristic and response speed) are also identified using the ETAP software.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.11
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• pp.1595-1600
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• 2012

This paper shows an improvement of the WRSM (Wound Rotor Synchronous Motor) by satisfying the voltage limit condition at high speed. After that, it compares the performance of the improved WRSM to that of the IPMSM (Interior Permanent Magnet Synchronous Motor). The comparison has been made under the condition where the dimension of the motor is identical to that of the IPMSM, having the rotor switched to a wounded rotor form. Moreover, this paper compares the Basic Model of the two motor, and estimates the parameters of the WRSM, thereby proposing the method to improve high speed performance. Furthermore, this paper presents the feasibility of switching the conventional motor into rare-earth-free motors for traction purpose.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.11
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• pp.1601-1605
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• 2012

Three-phase voltage and current is applied to the three-phase alternating current motors which are commonly used in industry. Three phase variables of a, b, c are converted into d, q, 0 axis and the AC machines are modeled and analyzed. Basically the coordinate transformation or d-q transformation is used for convenience, a few steps are needed to analyze the motor performances - separating d and q components, establishing each equivalent circuit, and solving the differential equations of the circuits. In this study, a modeling technique of induction motor using complex vector is proposed and it can explain the induction motor physically. This method does not need the separating process of d and q components. With this technique, the model becomes simple, is easy to understand in physical, and can get the same results with those from the other models. These simulation results of the proposed model are compared with them for the conformation of the proposed method.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.1
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• pp.49-56
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• 2009

This paper shows the characteristic analysis of single-phase line start permanent magnet (LSPM) motors considering the overhang structure. To achieve the low-cost design of an LSPM motor, the overhang structure is adapted for the rotor with a constraint of a fixed magnet volume. To obtain the dynamic and steady performance of the motor, the circuit parameters are extracted using the 3D-static FEM(Finite Element Method) and the d-q equivalent circuit is used. The performance of the model with overhang is compared with the conventional model without overhang on the condition that both models have a fixed volume for the permanent magnet.

• Journal of Electrical Engineering and Technology
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• v.10 no.3
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• pp.1007-1014
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• 2015

An optimally designed six-phase induction motor (6PIM) is compared with an initial design induction motor having the same ratings. The Genetic Algorithm (GA) method is used for optimization and multi objective function is considered. Comparison of the optimum design with the initial design reveals that better performance can be obtained by a simple optimization method. Also in this paper each design of 6PIM, is simulated by MAXWELL_2D. The obtained simulation results are compared in order to find the most suitable solution for the specified application, considering the influence of each design upon the motor performance. Construction a 6PIM based on the information obtained from GA method has been done. Quality parameters of the designed motors, such as: efficiency, power losses and power factor measured and optimal design has been evaluated. Laboratory tests have proven the correctness of optimal design.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.697-698
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• 2008

This paper deals with finite element characteristic analysis of brushless DC motor according to magnetic property measurement methods. Magnetic property data for non-oriented (NO) electrical steel for electric motors are measured by the Epstein test which is considered as the international standards. Data from Epstein test may result in discrepancy from motor characteristic tests due to innate anisotropic property of NO electrical steel. Finite element analysis were performed for a BLDC motor by various measurement methods such as Epstein test, Ring test and single sheet test (SST), and calculated results were compared with considering anisotropic property conditions.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.669-670
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• 2008

본 논문에서는 발전소나 민간 사업소에서 쓰이는 3.3kV급 대용량 고압모터를 진단하기 위한 휴대장비 개발에 관하여 언급하였다. 본 과제에서 개발된 휴대장비는 모터에 입력되는 3상 전압 및 전류값을 체크하여 주파수 성분등의 Power Quality 성분을 분석하는 방식으로서 모터의 진동을 검사하는 방식과 병행하여 널리 쓰이고 있으며 여러 가지 해외 제품들이 존재한다. 본 과제에서는 이러한 해외 제품을 국산화하는데 초점이 맞추어져 있다.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.762-763
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• 2008

The purpose of this paper is to investigate and compare the inductance evaluation methods of interior permanent magnet synchronous motors (IPMSM). Three major finite element methods are discussed. Their detail calculation processes will be presented as well as their fundamental principles. Not only the results, but also their solving method, computation time and complexity also will be compared. Finally, the calculated results will be verified with an experiment.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.881-882
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• 2008

For the interior permanent magnet synchronous motor(IPMSM) drive to operate above the base speed in the constant horsepower region, the field weakening control is applied. However, the field weakening control was not almost applied to sensorless control of the interior permanent magnet synchronous motor. In this paper, the field weakening control is applied to the sensorless control of IPMSM based on the fuzzy controller. The effectiveness of the proposed system is verified by the experimental results.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.1712-1713
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• 2008

In this paper, we develop the vision control systems of auto tracking based on image processing techniques for video conference. The developed auto tracking vision control system consists of control hardware including vision, two dc motors and dc motor drivers. Image processing techniques are used to pixel of two images. Motion detection algorithm is applied to eliminate the noise. Experiment results are presented to illustrate the effectiveness and the applicability of the approaches proposed.