http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
C.S.Ma,T J. Kim,D W. Kang,D.S. Hyun 전력전자학회 2003 JOURNAL OF POWER ELECTRONICS Vol.3 No.4
This paper proposes a simple control strategy based on the discontinuous PWM (DPWM) to balance the DC-link voltage of three-level neutral-point-clamped (NPC) inverter at low modulation index. It introduces new DPWM methods in multi-level inverter and one of them is used for balancing the DC-link voltage. The current flowing in the neutral point of the DC-link causes the flnctuation of the DC-link voltage of the NPC inverter. The proposed DPWM method changes the path and duration time of the neutral point current, which makes the overall fluctuation of the DC-link voltage zero during a sampling time of the reference voltage vector. Therefore, by using the proposed strategy, the voltage of the DC-link can be balanced fairly well and the voltage ripple of the DC-link is also reduced significantly Moreover, comparing with conventional methods which have to perform the complicated calculation, the proposed strategy is very simple The validity of the proposed DPWM method is verified by the experiment
SCHOTTKY PROPERTIES OF ION BEAM DEPOSITED W-Si-N REFRACTORY CONTACTS ON GaAs
Park, C. S.,Lee, J. S.,Yang, J. W.,Shim, K. H.,Lee, J. H.,Choe, Y. K.,Kang, J. Y.,Ma, D. S.,Lee, J. Y. 대한전자공학회 1989 ICVC : International Conference on VLSI and CAD Vol.1 No.1
We first tried low energy ion beam assisted deposition (IBAD) of refractory W-Si-N films onto GaAs for application to gate electrode of metal-semiconductor field effect transistors (MESFET). This ion beam technique provides lower process pressure, and less ion damage to substrates and films than conventional reactive sputter-deposition. The Schottky diode characteristics of W-Si-N contacts on GaAs and their thermal stability were investigated after annealing at 700-900℃ for 30 min. The Schottky barrier heights of W/, WN_(0 27)/, and WSi_(0 3)N_(0 4)/GaAs diodes annealed at 850 were 0.71, 0.84, and 0.76 eV respectively, which are comparable to those of the best results obtained by the conventional sputtering.
Current Transport Characteristics of 22.9 ㎸ High Temperature Superconducting Cable System
손송호(S. H. Sohn),임지현(J. H. Lim),류희석(H. S. Ryoo),양형석(H. S. Yang),최하옥(H. O. Choi),마용호(Y. H. Ma),김동락(D. L. Kim),류경우(K. W. Ryu),성태현(T. H. Sung),현옥배(O. B. Hyun),임성우(S. W. Lim),황시돌(S. D. Hwang) 대한전기학회 2008 대한전기학회 학술대회 논문집 Vol.2008 No.7(초록집)
Neutral-Point-Clamped 인버터의 저 변조지수에서 DC 링크 전압 균형을 위한 간단한 컨트롤 기법
마창수(C.S. Ma),김태진(T.J. Kim),강대욱(D.W. Kang),현동석(D.S. Hyun) 전력전자학회 2003 전력전자학술대회 논문집 Vol.2003 No.7(2)
This paper proposes a simple control strategy based on the discontinuous PWM(DPWM) to balance the DC-link voltage of three-level Neutral-Point-Clamped(NPC) inverters at low modulation index New DPWM methods in multi-level inverter are also introduced. The proposed DPWM method changes the path and duration to flow the neutral point current out of or into neutral point of the DC-link and it makes the overall fluctuation of the DC-link voltage zero during a sampling time of reference voltage vector Therefore, the voltage of the DC-link can be balanced fairly well and also the voltage ripple of the DC-link is reduced significantly Moreover, comparing with conventional methods, the proposed strategy is very simple. The validity of the proposed DPWM method is verified by experiment<br/>