http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
급속응고된 Fe-6.5wt% Si 강판의 미세조직과 자기적 특성에 미치는 열처리의 영향
황돈하,이갑호,이태행,구자명 ( D . H . Hwang,K . H . Lee,T . H . Lee,J . M . Koo ) 한국열처리공학회 1995 熱處理工學會誌 Vol.8 No.2
The alloying of 6.5wt% Silicon in iron decreases the magnetization and the anisotropy and minimizes the iron loss noticeably. But it is very difficult to make thin sheets because of its poor ductility which is due to an ordering reaction (body centered cubic to CsCl type crystal structure). However the ordering reaction can be suppressed by rapid solidification method. The cooling rate of rapidly solidified Fe-6.5wt% Si alloy is about 10³K/s and rapidly solidified structure are fine structure, cellular structure, dendrite and equiaxed grain from surface. The precipitates of DO₃Phase emerges on B₂matrix and the coercive force was 0.51 Oe (50cycle, 15KGauss) in Fe-6.5wt% Si alloy which was processed by heat treatment of 1150℃ for 1hr in high vacuum.
황돈하(D.H. Hwang),박도영(D.Y. Park),김용주(Y.J. Kim),김동희(D.H. Kim),구자윤(J.Y. Koo),이인우(I.W. Lee) 전력전자학회 2000 전력전자학술대회 논문집 Vol.2000 No.11
In this paper, the insulation characteristics test results of 25 low-voltage induction motors (3Φ, 5HP, 380V) are presented. Five different types of insulation techniques are applied to 25 motors. The maximum partial discharge (PD) magnitude (Qm), discharge inception voltage (DIV), dissipation factor tip-up (Δ tan δ), and rate of change in AC current (Δ I) are measured by PD and AC current tests Also, the insulation breakdown tests by high voltage pulse are performed, and the corresponding breakdown voltages are obtained.
횡자속형 영구자석 풍력발전기의 정상 및 과도상태 특성해석
황돈하(D.H. Hwang),강도현(D.H. Kang),김용주(Y.J. Kim),최경호(K.H.Choi),배성우(S.W. Bae),김동희(D.H. Kim) 전력전자학회 2002 전력전자학술대회 논문집 Vol.- No.-
The paper discuses characteristics of an axial-flux permanent-magnet generator for a gearless wind energy system which aims to be satisfied with variable operating conditions<br/> Design and construction of an axial-flux permanent- magnet generator with power output at 60 [Hz], 300 [r/min] for wind energy system is introduced. Finite-element method (FEM) is applied to analyze generator performance at variable load. The results of FE analysis show this generator is feasible for use with a wind turbine
IGBT PWM 인버터 구동 유도전동기의 절연성능 향상기술 연구
황돈하(D.H. Hwang),박도영(D.Y. Park),김용주(Y.J. Kim),이영훈(Y.H. Lee),김동희(D.H. Kim),이인우(I.W. Lee) 전력전자학회 2001 전력전자학술대회 논문집 Vol.2001 No.7
The recent advancements in power electronic switching devices have enabled high frequency switching operation and have improved the performance of pulse-width modulated (PWM) inverters for driving induction motors. But, the insulation failures of stator winding have attracted much concern due to high dv/dt of IGBT PWM inverter. In this paper, the test results for evaluation on the stator winding insulation of low-voltage induction motors for IGBT PWM inverter applications are presented The insulation characteristics are analyzed with partial discharge and dissipation factor tests. Also, insulation breakdown tests by switching pulse voltage are performed. An effective insulation technique to enhance the insulation strength is suggested from the test results.<br/>