• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 A
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• pp.228-231
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• 1998

Canned-motor of 3-phase induction is to be used for MCP. Its design and analysis are performed considering the effect of eddy-current loss induced in the can. The effect of inverter of canned-motor is also considered as it is controlled by VVVF inverter for two operating points.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제49권5호
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• pp.320-326
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• 2000

The canned motor of 3-phase induction is used for main coolant pump(MCP). The type of motor is canned-motor that stator and rotor are welded by sealed can. So, cooling water flows in the air gap of the canned motor as an independent cycling cooling system from the air gap to yoke of the motor to prevent high temperature of stator can and to lubricate bearing. Heat exchange is occurred between cooling water in the air gap and cooling water from the exterior pump to prevent rising of temperature in the motor. I has to analyze the characteristics of can exactly because the loss and the heat in the can are very important to design MCP. Therefore, thermal analysis is studied considering the effect of eddy-current los induced in the can.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제49권5호
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• pp.297-304
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• 2000

The motor for torpedo propulsion is needed the compact and short rating high power characteristics. This paper describes the development of the motor through the theory and Finite Element Method(FEM) analysis for Brushless Direct Current Motor(BLDCM) of 7 phase 6 poles. Back EMF, inductance and eddy current loss were analyzed. The proposed methods like magnetic wedge acquired by these FEM analysis were introduced. Phase-leading angle using encoder was used. Test results on the motor of 7 phase 6 poles were showed the validity of proposed methods and phase-leading angle.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.23-25
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• 2005

This paper describes analysis of transformer sheet winding losses and temperature rise. Sheet windings are used if transformer rating currents are so high that one meets current density limit on windings. Unlike stranded windings, sheet windings may be locally healed due to R direction flux. Winding losses with eddy current effect are calculated by finite element electromagnetic analysis and temperature rise is also calculated by Computational Fluid Dynamics (CFD) with loss result.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 추계학술대회 논문집 학회본부A
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• pp.97-99
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• 1998

This paper presents a numerical study of the behavior of the transformer winding, when stressed by the standard impulse voltage. The mathematical model of the transformer takes several points into the account. Capacitance of not adjacent winding as well as adjacent winding, eddy current loss caused by self and mutual inductance given as the functions of frequency. Not like the previous approach where calculation of capacitance is performed, in average sense. In this paper, capacitance of both adjacent and not adjacent winding is calculated using the numerical approach(B.E.M.), so they can get the more accurate value of capacitance. Because of frequency dependency of inductance, numerical-laplace-transform technique is required. Finally, to validate this approach, a simple test winding is simulated.

• 한국반도체및디스플레이장비학회:학술대회논문집
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• 한국반도체및디스플레이장비학회 2005년도 추계 학술대회
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• pp.197-202
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• 2005

Due to high permeability of the ferrite core, the characteristics of the ICP are expected to be greatly improved. We investigated the effect of the ferrite cores on conventional inductively coupled plasma. It was observed that the current and voltage in ike ICP antenna are slightly decreased and the power transfer efficiency is increased. However, due to eddy current and hysterisis loss, plasma density in the ICP with the ferrite cores is not increased. It seems that the ICP with the ferrite cores at low frequency (${\~}$100kHz) will be greatly improved since the losses at the low frequency can be negligible.

• Journal of Magnetics
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• 제18권1호
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• pp.50-56
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• 2013

In this paper, the 6-switch inverter for the Flux-Reversal Motor (FRM) has been presented and compared to the 4-switch inverter for the FRM, which is more popular in cost effective applications. To analyze the FRM, we adopted the two-dimensional time-stepped voltage source finite element method (FEM) that uses the actual pulse width modulation (PWM) voltage waveforms as the input data. As the FRM characteristic analysis of actual pwm voltage input, the torque ripples and iron losses (eddy current and hysteresis loss) of the FRM can be precisely calculated. With the simulated and experimental results, the performance and limitations of the 4-switch FRM which is the cost effective drive compared to the 6-switch FRM drive are provided in more detail.

• Journal of Electrical Engineering and Technology
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• 제13권6호
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• pp.2292-2300
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• 2018

A field-circuit coupling model of a typical faulty generator is established to correct through-bolt end-region overheating and breakdown failure in a tubular hydro-generator. Using the model, eddy current loss and electromagnetic forces on through bolts under normal and failure conditions are analyzed and compared and the natural frequency of a through bolt is determined. Based on the analysis results, the causative mechanism of failure is revealed and targeted improvement design measures are proposed. The numerical results are found to be consistent with the actual fault characteristics, validating the design measure improvements. The results are useful in improving the design and manufacturing standards and enhancing the operational reliability of large tubular hydro-generators.

• 한국산업정보학회논문지
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• 제25권5호
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• pp.49-57
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• 2020

기존의 전기 모터는 큰 중량과 부피의 단점으로 항공기 적용에 적합하지 않다. 고온 초전도 (High-Temperature Superconducting: HTS) 모터는 전류 밀도와 자기장 밀도가 높으며 손실이 적어 일반 전기모터와 비교하여 크기와 무게를 크게 줄일 수 있다. 본 논문은 미래 항공기 전기 추진용 HTS 모터의 개념 설계 및 해석 결과를 제시한다. 회전속도가 7,200 RPM인 2.5 MW 용량의 HTS 모터를 설계하고 무게 대비 출력 비(kW/kg)를 분석하였다. HTS 모터 계자코일 (Field Coil)의 운전온도는 LH₂ (Liquid Hydrogen) 냉각을 고려하여 20K을 선정하였다. 고정자 권선 (Stator Winding)은 다상 구성 (Multi-Phase Configuration)으로 연결하였고 와전류 (Eddy Current) 손실을 최소화하기 위해 Litz 선을 사용하였다. 결과적으로 모터의 무게 대비 출력 비는 약 18.67 kW/kg으로 기존 모터보다 훨씬 높음을 확인하였다.

• 한국전자통신학회논문지
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• 제9권4호
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• pp.527-536
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• 2014

본 논문에서는 마이크로그리드 적용을 위한 50kW 풍력발전기를 설계하였으며, 발전기의 해석은 maxwell 2D 상용프로그램을 사용하였다. 특히 제안된 PMSG는 코깅토크를 줄이고자 offset과 skew를 적용하였다. 최적의 옵셋과 스큐는 2mm와 전기각 60도를 제안하였다. 부하운전시 모의결과는 평균 고조파 1.3%, 전압 322.41V, 전류 94.95A, 철손 9.73W, 와류손 73.68W, 동손 3.52kW로 나타났다. 계산된 발전기 용량은 61.56kW이며, 제안된 설계절차는 더 큰 용량의 발전기설계에 적용할 수 있다.