• Journal of the Korean Solar Energy Society
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• v.34 no.2
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• pp.8-15
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• 2014

The objective of this paper is to suggest a design topology of permanent magnet synchronous generator with 2,000kW capacities for wind turbine. The suggested topology is to provide 3 split magnet PMSG instead of single magnet, and performed an analysis of eddy current loss and iron loss for suggested type using ansoft maxwell commercial program. The simulation results of suggested magnet type show there duction of eddy current loss as 13.87kW with loadless conditions and23.48kW with rated conditions, but iron loss for rotor yoke show the in creasing trend as2.2kW with loadless conditions and 0.2kW with rated conditions. The suggested 3 split maget type is to identified as more useful for 2,000kW PMSG.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.50 no.10
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• pp.509-516
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• 2001

Isolated phase bus(IPS) has a special structure for carrying large current generated by a generator to a main transformer. In the analysis of IPB, the understanding of the magnetic field distribution generated by large current is important. Especially, while the bus conductor current is flowing, almost same amount of current as bus conductor current is induced in the enclosures under the influence of time varying magnetic field, and therefore the large electric loss and the deterioration of insulating capability might occur due to Joule heating effect. Hence for the optimal design of IPB satisfying the condition to minimize the loss, the accurate analysis of magnetic field distribution and the eddy current characteristics of three phase isolated phase bus have been investigated. In the analysis of time varying magnetic field, instead of finite difference method(FDM) which is generally used, finite element method with phasor concept is investigated under the assumption that the bus current is purely sinusoidal. The characteristics is studied along the phase angle by comparing the effect of eddy current on the magnetic field distribution with the case that eddy current is not considered, and also the effect of material, thickness and radius of enclosure on the eddy current distribution is discussed.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.24 no.3
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• pp.33-38
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• 2010

In this paper, the nature of iron loss in electrical steel during alternating field excitation is investigated more precisely. The exact definition of AC iron loss is cleared by accurately measuring the iron loss for conditions of both the sinusoidal magnetic field and sinusoidal magnetic flux density. The results of this approach to iron loss calculations in electrical steel are compared to experimentally-measured losses. In addition, an inverse hysteresis model considering eddy current loss was developed to analyze the iron loss when the input is the voltage source. With this model, the inrush current in the inductor or transformer as well as the iron loss can be calculated.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.28 no.8
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• pp.508-512
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• 2015

Some insulating materials are tested and analyzed with variables to obtain the reliable pressboard which is located to core and coil of high voltage transformer. The high voltage transformer is used in electrical power system and operating reliability. Optimization possibility of pressboard shape including electrical insulation performance could be achieved by analysis simulation. Using insulating pressboard, which is made by mold applied eddy current loss, it could be measured the influences of moisture content for electrical properties. As a result, it is to contribute to improve the performance and ensure the reliability of the pressboard by investigating electrical strength according to the variation oil temperature. In addition pressboard thickness is important design factor to ensure electrical strength in high voltage transformer.

• Proceedings of the KIEE Conference
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• 2005.07b
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• pp.987-989
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• 2005

Axi-periodic analysis using magnetic vector potential is formulated in time harmonic field and applied to the field analysis for the end region of large turbo generator in this paper. By using axi-periodic analysis, the effect of flux shield, one of the structure placed in the end region of large turbo generator to prevent stator end from thermal damage, is studied, and eddy current loss in the flux shield is estimated for operation conditions. 3D FEA is used for the verification of presented analysis method. Because 3D flux distribution can be calculated with 2D modeling, magnetic field showing 3D distribution can be effectively calculated by axi-periodic analysis comparing with 3D FEA.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.48 no.1
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• pp.29-33
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• 1999

Superconducting tape is being developed for electrical equipment such as superconducting transformers and generators etc. AC loss reduction is primary concerned in the development of such high-efficiency equipment. AC losses in Bi-2223 silver-sheathed tapes, both single and multi-filamentary, were investigated by means of AC magnetization techniques when longitudinal fields are applied. The experiment resultswere compared with the hysteresis loss equation based on Bean model and the eddy current loss equation. The AC loss of the mono-filamentary tape was dominated by the hysteresis. On the contrary, the AC loss of the multi-filamentary tape was substantially dominated by the eddy current loss in the silver matrix.

• Journal of Magnetics
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• v.18 no.3
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• pp.268-275
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• 2013

This paper shows the characteristics of performance for interior permanent magnet machine (IPM) considering driving conditions such as maximum torque per ampere (MTPA) and flux-weakening control especially in terms of harmonic loss. In particular, based on finite element analysis (FEA), permanent magnet (PM) eddycurrent loss and the harmonic iron loss have been computed where the models have been intentionally designed to identify the effects of pole-slot combinations on the loss while maintaining the required power for electric vehicle. From the analysis results, it was shown that the rotor iron loss and PM eddy-current loss of machine employing fractional slot winding are extremely large at load condition. Furthermore, it was revealed that the harmonic iron loss at high-speed operation is mainly distributed over stator teeth and rotor surface, which may aggravate cooling system of the rotor structure in the vehicle.

• Proceedings of the Korean Magnestics Society Conference
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• 2014.05a
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• pp.105-105
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• 2014

• Journal of the Korean Magnetics Society
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• v.9 no.3
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• pp.149-153
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• 1999

Frequency and temperature dependence of magnetic loss has been investigated in Mn-Zn ferrites containing the sesistive temary compounds of $SiO_2-CaO-V_2O_5$. The Mn-Zn ferrite with the composition of $MnO:ZnO:Fe_2O_3=36:11:53$(by mol %) are prepared by self-propagating high-temperature synthesis. From the results of frequency dependence of core loss, it has been found that the hysteresis loss is dominant at low frequency and the eddy current loss becomes more dominant as the frequency increases. With the addition of resistive compound, the frequency dependence of core loss, it has been found that the hysteresis loss is dominant at low frequency and the eddy current loss becomes more dominant as the frequency increases. With the addition of resistive compound, the frequency region where the hysteresis loss is dominant becomes wide. The core-loss minimum occurs at about 4$0^{\circ}C$ in the specimens with the additive because of the reduction in eddy current loss.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.1073-1074
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• 2011

The loss is most important problems for the practical applications of permanent magnet synchronous motor(PMSM). In this paper, rotor sleeve and stator shape design of high speed permanent magnet motor for loss reduction. First, this paper found optimum sleeve thickness for calculation eddy current loss on the basis of analytical method, because eddy current is influenced by conductivity of material and area. Then, stator shape design is changed as maintain same slot area for reducing stator core loss. Finally, this paper compared analytical result with optimum sleeve thickness obtained from finite element(FE) method, and stator core loss is calculated from FE method.