• Title/Summary/Keyword: Negative power

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Grid-connected Inverter Control Algorithm for Torque Ripple Compensation in Doubly-Fed Induction-type Wind Power Generation System (전원 전압 불평형시 이중여자 유도형 풍력발전 시스템의 토크 리플 저감을 위한 계통연계 인버터 제어 알고리즘)

  • Jeong, Byoung-Chang;Song, Seung-Ho
    • Proceedings of the KIEE Conference
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    • 2005.10c
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    • pp.317-319
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    • 2005
  • In this paper, control algorithm for torque ripple compensation in DFIG wind power generation system is proposed. A simple PI controller is designed for the negative sequence voltage cancellation using negative sequence currents in the grid-side converter. As a result, the stator voltage contains only the positive sequence components and the torque pulsation of the generator is effectively compensated. Propose algorithm is confirmed with PSCAD simulation model.

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A 200MHz high speed 16M SDRAM with negative delay circuit (부지연 회로를 내장한 200MHz 고속 16M SDRAM)

  • 김창선;장성진;김태훈;이재구;박진석;정웅식;전영현
    • Journal of the Korean Institute of Telematics and Electronics C
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    • v.34C no.4
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    • pp.16-25
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    • 1997
  • This paper shows a SDRAM opeating in 200MHz clock cycle which it use data interleave and pipelining for high speed operation. We proposed NdC (Negative DEaly circuit) to improve clock to access time(tAC) characteristics, also we proposed low power WL(wordline)driver circit and high efficiency VPP charge-pump circit. Our all circuits has been fabricated using 0.4um CMOS process, and the measured maximum speed is 200Mbytes/s in LvTTL interface.

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Microwave-Induced Negative-Differential Resistance Observed in Josephson Junction (마이크로파가 조셉슨 접합에서 유발하는 부의 미분저항)

  • Kim, Kyu-Tae;Koutovoi, Viatcheslav D.;Hong, Hyun-Kwon
    • 한국초전도학회:학술대회논문집
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    • v.9
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    • pp.237-237
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    • 1999
  • We have observed that a stable and reproducible Negative Differential Resistance(NDR) is induced by external microwave at low power in Nb/AlO$_x$/Al/Alo$_x$/Nb junctions. To study the erratic and pozzling NDR observations we have simulated Stewart-McCumber model in the region. Experimental results and simulation results will be presented with a discussion to draw a dynamic interpreration of the NDR.

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A Study on the Binding Power of Interim Measures and the Effect of Interim Measure Non-Compliance in ICSID Arbitration (ICSID 중재의 임시적 처분 구속력과 미준수 효과에 관한 연구)

  • Ha, Hyun-Soo
    • Journal of Arbitration Studies
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    • v.30 no.2
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    • pp.3-21
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    • 2020
  • This study focuses on the binding power of the interim measures of the arbitral tribunal in ICSID arbitration and the effects of non-compliance. Upon consideration of the intentions of those who made these rules, given the interpretation of the provisions of Article 47 of the ICSID Convention and Article 39 of the ICSID Arbitration Rules, it was found reasonable to consider that the interim measures made by the arbitral tribunal in ICSID arbitration were not binding. However, in actual ICSID arbitration, most arbitral tribunals approve the binding power of the interim measures based on the purposes and the characteristics of the interim measures. As such, there is a certain distance between the legislative intention for interim measures in ICSID arbitration and the judicial practice, but considering the demand for maintaining the integrity of the arbitration procedure, it is reasonable to consider that the interim measures are binding. In addition, the fact that the interim measures have binding power can increase the possibility that the party will comply with the interim measures. Thus, the binding power of interim measures not only encourages voluntary compliance to the interim measures of the party, but can also cause negative consequences for the party if it is not met. In other words, the arbitral tribunal will be able to form negative inferences against the party who does not comply with it in a procedural side, and in the practical side, the party who does not comply with the interim measures will be compensated for the additional damages for non-compliance.

STUDY ON THE POSITIVE POWER IN INTERPERSONAL RELATIONSHIP - (II) THE ISSUE OF TRUST - (대인관계(對人關係)에 있어서 긍정적(肯定的)인 힘에 대(對)한 연구(硏究) - (II) 신뢰(信賴) -)

  • Cho, Soo-Churl
    • Journal of the Korean Academy of Child and Adolescent Psychiatry
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    • v.7 no.1
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    • pp.3-13
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    • 1996
  • All human being can not exist by oneself That is, all human being depend on intimate attachment for their survival. Physical and psychological powers are prerequisites fir one's survival and these serve important functions hi interpersonal relationships. There are two kinds of powers. One is positive power which helps one survive effectively. Another one is negative power which disturbs one's effective survival. In this paper, the author reviewed the precept of 'trust' which is described in 'Bible' and oriental classical books such as 'The Analects of Confuicus' and 'Tao Te Ching' etc. and tried to integrate this precept with the importance in everyday life, 'How to communicate' is closely related to 'trust' and one's speech is closely related to one's thinking or emotion. Thus in order to keep trustful communication, one has to introspect oneself to understand one's own emotional reaction.

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A Study on the Self-Excited Mixing effect of IMPATT Diodes (IMPATT 다이오드의 백여혼합에 관한 연구)

  • Park, Gyu-Tae;Lee, Jong-Ak;Lee, Tae-Ho
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.11 no.2
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    • pp.5-11
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    • 1974
  • Theoretical analysis is carried out for the beat frequency generation phenomena in the IMPATT diodes an4 the experimental studies are given in parrallel. The theory is based on the space charge modulation effect introduced to the multiplication process by the input signal. Computed results show that the beat frequency output power is linearly dependent upon the signal power and self oscillating power. Also the strong dependence of the output power with respect to the diode negative resistance is found and it turns out that the larger the negative resistance, the stronger the beat frequency output power. Experimental results show a good agreement with the theoretical values. Calculated conversion gain is about -0.4[db] at 10[GHz] and the experimental value shows -6.2[db] below this value. This difference between the theoretical and the experimental values is considered to be the results of the ineffective injection of signal power.

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A Study on the One-Stage 3-Dimensional Axial Turbine Performance Test with Different Incidence Angle (입사각 변경에 따른 단단 3차원 축류형 터빈의 성능시험에 관한 연구)

  • 조수용;박찬우
    • Journal of the Korean Society of Propulsion Engineers
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    • v.5 no.2
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    • pp.24-31
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    • 2001
  • An axial-type turbine design technology is developed. In order to design one-stage turbine, the preliminary design method is applied, and then design parameters are chosen after analyzing gas properties within the turbine passage using the streamline curvature method. Stator blade is designed using C4 profile, and rotor blade is designed using shape parameters. Stator is manufactured as an integral type and rotor is manufactured to be disassembled from the disc for changing blade incidence angle. The output power from the rotor is measured with various RPM and input power. Experimental results show that the maximum efficiency of turbine rotor is obtained on the design point, and the output power is proportionally decreased with the negative incidence angle even the test turbine is a reaction turbine. The efficiency of turbine rotor is decreased to 5% by $7.5^{\cire}$ negative incidence angle from the designed value.

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COMBUSTION STABILITY OF DIESEL-FUELED HCCI

  • Shi, L.;Deng, K.;Cui, Y.
    • International Journal of Automotive Technology
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    • v.8 no.4
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    • pp.395-402
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    • 2007
  • Homogeneous Charge Compression Ignition (HCCI) shows great potential for low $NO_x$ emission but is hampered by the problem of no direct method to control the combustion process. Therefore, HCCI combustion becomes unstable easily, especially at lower and higher engine load. This paper presents a method to achieve diesel-fueled HCCI combustion, which involves directly injecting diesel fuel into the cylinder before the piston arrives at top dead center in the exhaust stroke and adjusting the valve overlap duration to trap more high temperature residual gas in the cylinder. The combustion stability of diesel-fueled HCCI combustion and the effects of engine load, speed, and valve overlap on it are the main points of investigation. The results show that: diesel-fueled HCCI combustion has two-stage heat release rate (low temperature and high temperature heat release) and very low $NO_x$ emission, combustion stability of the HCCI engine is worse at lower load because of misfire and at higher load because of knock, the increase in engine speed aids combustion stability at lower load because the heat loss is reduced, and increasing negative valve overlap can increase in-cylinder temperature which aids combustion stability at lower load but harms it at higher load.

Inertial Control of a DFIG-based Wind Power Plant using the Maximum Rate of Change of Frequency and the Frequency Deviation

  • Lee, Hyewon;Kim, Jinho;Hur, Don;Kang, Yong Cheol
    • Journal of Electrical Engineering and Technology
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    • v.10 no.2
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    • pp.496-503
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    • 2015
  • In order to let a wind generator (WG) support the frequency control of a power system, a conventional inertial control algorithm using the rate of change of frequency (ROCOF) and frequency deviation loops was suggested. The ROCOF loop is prevailing at the initial stage of the disturbance, but the contribution becomes smaller as time goes on. Moreover, its contribution becomes negative after the frequency rebound. This paper proposes an inertial control algorithm of a wind power plant (WPP) using the maximum ROCOF and frequency deviation loops. The proposed algorithm replaces the ROCOF loop in the conventional inertial control algorithm with the maximum ROCOF loop to retain the maximum value of the ROCOF and eliminate the negative effect after the frequency rebound. The algorithm releases more kinetic energy both before and after the frequency rebound and increases the frequency nadir more than the conventional ROCOF and frequency loops. The performance of the algorithm was investigated under various wind conditions in a model system, which includes a doubly-fed induction generator-based WPP using an EMTP-RV simulator. The results indicate that the algorithm can improve the frequency drop for a disturbance by releasing more kinetic energy.

An Electrical Repair Circuit for Yield Increment of High Density Memory (고집적 메모리의 yield 개선을 위한 전기적 구제회로)

  • 김필중;김종빈
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.13 no.4
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    • pp.273-279
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    • 2000
  • Electrical repair method which has replaced laser repair method can replace defective cell by redundancy’s in the redundancy scheme of conventional high density memory. This electrical repair circuit consists of the antifuse program/read/latch circuits, a clock generator a negative voltage generator a power-up pulse circuit a special address mux and etc. The measured program voltage of made antifuses was 7.2~7.5V and the resistance of programmed antifuses was below 500 Ω. The period of clock generator was about 30 ns. The output voltage of a negative voltage generator was about 4.3 V and the current capacity was maximum 825 $mutextrm{A}$. An antifuse was programmed using by the electric potential difference between supply-voltage (3.3 V) and output voltage generator. The output pulse width of a power-up pulse circuit was 30 ns ~ 1$mutextrm{s}$ with the variation of power-up time. The programmed antifuse resistance required below 44 ㏀ from the simulation of antifuse program/read/latch circuit. Therefore the electrical repair circuit behaved safely and the yield of high densitymemory will be increased by using the circuit.

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