• Proceedings of the KIEE Conference
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• 2003.10b
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• pp.9-11
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• 2003

This paper deals with the comparison of rotor eddy current losses In two types of permanent magnet high-speed machines. The analytical method and two dimensional finite element analysis have been used to evaluate the rotor eddy current loss with the rotor magnetization Pattern. It is shown that the Halbach array produce rotor loss less than parallel magnetization.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.101-102
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• 2011

The attraction force is an important parameter for permanent-magnet(PM) linear machines. This paper aims to analysis lumped magnetic circuit model of a magnetic levitation system. It accounts for the fringing effect and leakage flux which may greatly affect the accuracy of the analytical model for the optimal lumped magnetic circuit model. consequentially it will be able to apply to prospective permanent-magnet(PM) linear machines for accurate analysis.

• Proceedings of the KIEE Conference
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• 2007.04c
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• pp.56-58
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• 2007

This paper deals with analytical prediction for the cogging torque of permanent magnet machines with multi-pole rotor First. open-circuit field solutions are derived using a magnetic vector potential and a two-dimensional (2-d) polar coordinate systems. On the basis of derived open-circuit field solutions and 2-d permeance functions. we also derive the analytical solutions for the open-circuit field considering stator slotting effects and cogging torque. All analytical results are shown in goof agreement with those obtained from finite element (FE) analyses.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.1617-1620
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• 2005

The current control for interior permanent magnet machines is more complicate than surface permanent magnet machine because of its torque characteristic depending on the reluctance. For high performance torque control, it requires state decoupling between the d-current and q-current dynamics. However the variation of the inductances, which couples the state dynamics of the currents, makes the state decoupling difficult. So some decoupling methods have developed to cope this variations and each current can be regulated independently. This paper presents a novel approach for fully decoupling the states cross-coupling using parameter adaptation. The adaptation method is based on the error between reference currents and the currents with state decoupling which have to follow the references. This method is more object-oriented than the other online parameter estimation methods in IPM machine and other electrical machines

• Journal of international Conference on Electrical Machines and Systems
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• v.2 no.1
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• pp.51-56
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• 2013

With the active development of hybrid electric vehicle (HEV), the application of interior permanent magnet synchronous motor (IPMSM) has been expanded. As wide driving region of IPMSM for electric vehicle (EV) traction motor is required, many studies are conducted to improve characteristics of a motor in both low and high-speed driving regions. A motor in high-speed driving region generates (produces) large stress to the rotor. Thus, the rotor needs to be designed considering the mechanical safety. Therefore, in this paper, we conducted stress analysis and electromagnetic analysis to determine the centerpost's distance which is considered important during the design of IPMSM for EV traction motor in order to secure mechanical safety and satisfy specifications of output requirement.

• Journal of international Conference on Electrical Machines and Systems
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• v.2 no.1
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• pp.16-22
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• 2013

This paper presents the analysis and optimization of air-core permanent magnet linear synchronous motor with overlapping concentrated windings to achieve high thrust density, high thrust per copper losses and low thrust ripple. For the motor design, we adopt equivalent magnetizing current (EMC) method to analyze the magnetic field and give analytical formulae for calculation of motor parameters such as no-load back EMF, dynamic force, thrust density and thrust per copper losses. Further, we proposed a multi-objective optimization by genetic algorithm to search for the optimum parameters. The design optimization is verified by 2-D Finite Element analysis (FEA).

• Journal of international Conference on Electrical Machines and Systems
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• v.1 no.1
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• pp.17-22
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• 2012

This paper presents analyzed results of a permanent magnet motor by using complex E&S modeling. The calculated results are compared with ones from the conventional E&S modeling for verification. Combinations of the numbers of slots and poles are investigated to reduce total iron loss. The results demonstrate that the complex E&S modeling is very useful in design under consideration of rotational magnetic field and magnetic anisotropy.

• Proceedings of the KIEE Conference
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• 2003.07b
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• pp.939-941
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• 2003

High Speed permanent magnet machines are currently being developed for a number of applications including gas turbine power plants, air conditioning systems, machine tools, gas pumps, high performance vacuum pumps, flywheel energy storage systems, aircraft fuel pumps, and so on. Using a high-speed machine eliminates the necessity of the mechanical gearbox and could certainly increase the system efficiency and reduce the total cost. In addition, a high-speed machine has the advantage of small dimension and low weight, i.e. low weight to power and volume to power ratio. This paper presents a review of some important applications (mostly still under development) where high-speed machines arc used, highlighting the advantages of the technology in each case.

• Journal of Electrical Engineering and Technology
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• v.13 no.6
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• pp.2329-2334
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• 2018

This paper discusses the thermal effect of the number of permanent-magnet (PM) layers in an outer rotor machine. Depending on the number of axial-layer of PM, the operating temperature is compared analytically and experimentally. The electromagnetic analysis is performed using 3-dimensional time varying finite element method to get the heat sources depending on axial-layered PM models. Then thermal analysis is conducted using the lumped-parameter-thermal-network method for each case. Two outer rotor machines, which have the different number of axial-layer of PM, are manufactured and tested to validate the analysis results.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.5
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• pp.765-771
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• 2017

This paper presents concurrent design methods of surface permanent magnet synchronous machines for saliency-tracking self-sensing position estimation. Magnetic saliency for the self-sensing is created by stator pole saturation due to the rotor zigzag leakage flux. The power conversion properties such as saliency ratio, torque ripple, and efficiency vary according to motor design. The property change due to design modification is analysed by using finite element analysis, and with the appropriate design modification, proper saliency is created while preserving their power conversion capabilities.