• Title/Summary/Keyword: Phase Balance

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Scale Down Design on Experiment Facility of the Water/Steam Receiver for Solar Power Tower (타워형 태양열 흡수기의 열전달 특성 실험장치에 관한 연구)

  • Seo, Ho-Young;Kim, Jong-Kyu;Kang, Yong-Heack;Kim, Yong-Chan
    • 한국신재생에너지학회:학술대회논문집
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    • 2007.06a
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    • pp.676-679
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    • 2007
  • This paper describes an experiment facility to measure the circulation characteristics of a water/steam receiver at various heat fluxes. The natural circulation type receiver was considered in this study. The experiment facility was designed to satisfy circulation balance with an appropriate scale down. As a result, riser tube inner diameter was 7.4 mm and water circulation was 0.319 kg/s. Downcomer tube inner diameter by circulation balance was 9.52 mm and the quality was from 0 to 0.23.

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A Technique for Accurate Measurement of Power System Frequency (전력설비의 정밀주파수진단을 위한 기법)

  • Nam, S.B.;Lee, H.G.
    • Proceedings of the KIEE Conference
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    • 2006.05a
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    • pp.66-70
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    • 2006
  • Frequency is an important operating parameter of a power system. Electric power systems sustain transient frequency swings whenever the balance between generation and load does not no longer hold. To cope with this Constraints, il requires an accurate and high speedy frequency deviation estimation technique and suitable adjustment to obtain the power system energy balance. This paper describes the design, computational aspects and implementation of an iterative technique for measuring power system. The rate change of the phase angle is used for estimation. To confirm the validity of the proposed algorithm, the simulation studies carried out on a typical 154[KV] double T/L system by using EMTP software. Some test results are presented in the paper.

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Design of tall residential buildings in Singapore for wind effects

  • Balendra, T.;Ma, Z.;Tan, C.L.
    • Wind and Structures
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    • v.6 no.3
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    • pp.221-248
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    • 2003
  • The design of high-rise building is often influenced by wind-induced motions such as accelerations and lateral deflections. Consequently, the building's structural stiffness and dynamic (vibration periods and damping) properties become important parameters in the determination of such motions. The approximate methods and empirical expressions used to quantify these parameters at the design phase tend to yield values significantly different from each other. In view of this, there is a need to examine how actual buildings in the field respond to dynamic wind loading in order to ascertain a more realistic model for the dynamic behavior of buildings. This paper describes the findings from full-scale measurements of the wind-induced response of typical high-rise buildings in Singapore, and recommends an empirical forecast model for periods of vibration of typical buildings in Singapore, an appropriate computer model for determining the periods of vibration, and appropriate expressions which relate the wind speed to accelerations in buildings based on wind tunnel force balance model test and field results.

A Technique for Fast and Accurate Measurement of Power System Frequency (전력계통 주파수의 고속.정밀측정을 위한 기법)

  • Nam, S.B.;Lee, H.G.;Ma, S.B.
    • Proceedings of the KIEE Conference
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    • 2004.07e
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    • pp.68-71
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    • 2004
  • Frequency is an important operating parameter of a power system. Electric power systems sustain transient frequency swings whenever the balance between generation and load does not no longer hold. To cope with this Constraints, it requires an accurate and high speedy frequency deviation estimation technique and suitable adjustment to obtain the power system energy balance. This paper describes the design, computational aspects and implementation of an iterative technique for measuring power system. The rate change of the phase angle is used for estimation. To confirm the validity of the proposed algorithm, the simulation studies carried out on a typical 154[KV] double T/L system by using EMTP software. Some test results are presented in the paper.

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An Iterative Technique for Fast and Accurate Measurement of Power System Frequency (전력계통 주파수의 고속.정밀측정을 위한 반복기법)

  • Nam, S.B.
    • Proceedings of the KIEE Conference
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    • 2003.07e
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    • pp.92-95
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    • 2003
  • Frequency is an important operating parameter of a power system. Electric power systems sustain transient frequency swings whenever the balance between generation and load does not no longer hold. To cope with this Constraints. it requires an accurate and high speedy frequency deviation estimation technique and suitable adjustment to obtain the power system energy balance. This paper describes the design, computational aspects and implementation of an iterative technique for measuring power system. The rate change of the phase angle is used for estimation. To confirm the validity of the proposed algorithm, the simulation studies carried out on a typical 154[KV] double T/L system by using EMTP software. Some test results are presented in the paper.

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Wettability Analysis of Liquid Phase in Partial Melted Solders Using Wetting Balance

  • Park, J.Y.;Ha, J.S.;Kang, C.S.;Kim, M.I.;Shin, K.S.;Jung, J.P.
    • Proceedings of the International Microelectronics And Packaging Society Conference
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    • 2000.04a
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    • pp.81-86
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    • 2000
  • To evaluate the possibility of the partial melting soldering. wettability of partial melted solders was measured using wetting balance. Off eutectic Sn-Pb allows are wettable in their partial melting zone. Especially, Pb rich alloys showed excellent wettability while wettability of Sn rich alloys were adequate or poor. It is found that wettability increases over $200^{\circ}C$ regardless of composition liquid fraction and phases of the original alloy Sn-7Ag alloy showed good wettability in their partial melting zone, while Sn-65Bi alloy was non-wettable under their melting points.

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Interface Deformation and Lippmann-Young equation in Electrowetting (전기습윤현상에서의 계면 변형과 Lippmann-Young 식)

  • Hong, Jin-Seok;Kang, Kwan-Hyoung;Kang, In-Seok
    • 한국전산유체공학회:학술대회논문집
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    • 2008.03b
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    • pp.589-592
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    • 2008
  • For the system of a droplet on an insulator-coated electrode, the Lippmann-Young equation is derived by considering the deformation of interface near the three-phase contact line. The equation governing the deformation of interface, which describes the local balance of the Maxwell stress and the capillary pressure, is integrated along the interface. The integration leads to the Lippmann-Young equation which is shown to represent the macroscopic balance of horizontal force acting on entire meniscus. Young's angle is assumed to be not affected by the Maxwell stress. The meaning and validity of the assumption are discussed.

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Galloping Algorithm of Quadruped Robots on Irregular Surface (비평탄면에서의 4 족 로봇의 갤로핑 알고리즘)

  • Shin, Chang-Rok;Park, Jong-Hyeon;Yoo, Hong-Hee
    • Proceedings of the KSME Conference
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    • 2008.11a
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    • pp.888-893
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    • 2008
  • In This paper proposes the control algorithm for quadruped robots on irregularly sloped uneven surface. Body balance is important in stable running locomotion. Since the body balance is determined by the forces applied at the feet during touchdown phase, the ground reaction force is controlled for stable running. To control the forces at each foot, the desired force is generated. The generated desired force is compared with actual contact force, then, the difference between them modifies the foot trajectory. The desired force is generated by combination of the rate change of the angular and linear momentum at flight. Then the rate change of momentum determines each force distribution. The distribution of the force is carried out by fuzzy logic. The computer simulation is carried out with the commercial software RecurDyn$^{(R)}$. Dynamic model simulation program show that the stable running on the irregularly sloped uneven surface are accomplished by the proposed method.

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A study on neutral-point voltage balance with harmonic component injection for single phase three-level NPC converter (고조파 주입을 통한 단상 3레벨 NPC 컨버터 중성점 전압 밸런싱 연구)

  • Kang, Kyoung Pil;Kim, Ho-Sung;Cho, Jintae;Cho, Younghoon
    • Proceedings of the KIPE Conference
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    • 2018.07a
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    • pp.316-317
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    • 2018
  • This paper propse the DC link capacitor voltage balancing control for three level neutral point clamped converter with harmonic component injection method. The injcetion voltage consists of harmonic component and DC link capacitor voltage difference. Theoretical analysis is provided to balance the DC link voltage, and it shows that harmonic component compensates the unbalanced condition between the capacitors. Both simulations and experiments are carried out to show that the voltage unbalance have been decreased by the proposed method.

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A Technique for Fast Measurement of Power System Frequency (전력계통 주파수의 고속측정을 위한 기법)

  • Nam, S.B.;Kim, Jin-Su;Ma, Seok-Beom
    • Proceedings of the KIEE Conference
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    • 2005.10a
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    • pp.145-149
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    • 2005
  • Frequency is an important operating parameter of a power system. Electric power systems sustain transient frequency swings whenever the balance between generation and load does not no longer hold. To cope with this Constraints, it requires an accurate and high speedy frequency deviation estimation technique and suitable adjustment to obtain the power system energy balance. This paper describes the design, computational aspects and implementation of an iterative technique for measuring power system. The rate change of the phase angle is used for estimation. To confirm the validity of the proposed algorithm, the simulation studies carried out on a typical 154[KV] double T/L system by using EMTP software. Some test results are presented in the paper.

  • PDF