• Title/Summary/Keyword: Load Combination

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Calculation of Loss of Load Expectation and Loss of Load Frequency using a Moment matching method (모멘트 대입법에 의한 전력부족 기대치와 빈도수의 산정)

  • Yoo, Hyun-Ho;Kim, Jin-O
    • Proceedings of the KIEE Conference
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    • 1998.07c
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    • pp.1076-1078
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    • 1998
  • This paper proposes a new approach for calculating frequency and duration by using the moment matching technique. Two separate expressions are derived, one for the loss of load expectation(LOLE) and the other for the loss of load frequency(LOLF). These expressions are combination of exponentials and are therefore easily integrable and can be readily evaluated. The proposed approach is quite comparable of with the other methods at the aspect of accuracy and efficiency.

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Load Modeling of Electric Locomotive Using Parameter Identification

  • Kim, Joo-Rak;Shim, Keon-Bo;Kim, Jung-Hoon
    • Journal of Electrical Engineering and Technology
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    • v.2 no.2
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    • pp.145-151
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    • 2007
  • Electric load components have different characteristics according to the variation of voltage and frequency. This paper presents the load modeling of an electric locomotive by the parameter identification method. The proposed method for load modeling is very simple and easy for application. The proposed load model of the electric locomotive is represented by the combination of the loads that have static and dynamic characteristics. This load modeling is applied to the KTX in Korea to verify the effectiveness of the proposed method. The results of proposed load modeling by the parameter identification follow the field measurements very exactly.

Modal Combination Method Considering Higher Mode Effects (고차모드 효과를 고려한 모드조합법)

  • Eom, Tae-Sung;Lee, Hye-Rin;Park, Hong-Gun
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2005.03a
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    • pp.185-192
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    • 2005
  • Using existing static methods, it is possible to estimate accurately the reponses of structures governed by the fundamental mode. However, these methods do not provide reliable estimates for the structure where higher mode effects are significant. Parametric study was performed to analyze the dynamic characteristics of the structure with long vibration period. Based on the investigations, a new modal combination method using modal combination coefficients, Factored Modal Combination, was developed, and static earthquake load patterns addressing higher mode effects reasonably were proposed. Existing modal combination methods, such as SRSS and CQC, lack a theoretical basis to be applied to inelastic structures. In contrast, the proposed method can be applied conveniently in inelastic range as well as in elastic range.

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An Intelligent Fault Detection and Service Restoration Scheme for Ungrounded Distribution Systems

  • Yu, Fei;Kim, Tae-Wan;Lim, Il-Hyung;Choi, Myeon-Song;Lee, Seung-Jae;Lim, Sung-Il;Lee, Sung-Woo;Ha, Bok-Nam
    • Journal of Electrical Engineering and Technology
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    • v.3 no.3
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    • pp.331-336
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    • 2008
  • Electric load components have different characteristics according to the variation of voltage and frequency. This paper presents the load modeling of an electric locomotive by the parameter identification method. The proposed method for load modeling is very simple and easy for application. The proposed load model of the electric locomotive is represented by the combination of the loads that have static and dynamic characteristics. This load modeling is applied to the KTX in Korea to verify the effectiveness of the proposed method. The results of proposed load modeling by the parameter identification follow the field measurements very exactly.

Load shedding case study of the refinery plant power system considering dynamic characteristic (정유공장 전력계통 동특성을 고려한 부하차단 적용 사례연구)

  • Lee, Kang-Wan;Lim, Joo-Il;Kim, Hyung-Tae
    • Proceedings of the KIEE Conference
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    • 2000.07a
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    • pp.61-65
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    • 2000
  • This paper presents the load shedding case studies and recommendations of load shedding scheme For improving the reliability to suit the requirements of LG-Caltex refinery plant power sγstem. It is recommended for LG-Caltex to decrease the total generation for the economic dispatch. When the LG-Caltex refinery is isolated from KEPCO utility system, the proper load shedding scheme should be implemented since total generation in LG-Caltex refinery plant is less than the load demand. According to the studies carried out the logic-based load shedding is recommended as the main protection scheme, with the combination of the under-frequency relay load shedding.

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Design loads for floating solar photovoltaic system: Guide to design using DNV and ASCE standards

  • Gihwan Kim;Moonsu Park
    • Structural Engineering and Mechanics
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    • v.89 no.2
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    • pp.171-179
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    • 2024
  • The market of the floating solar photovoltaic system is rapidly growing around the world with the rise of renewable energy that can replace fossil energy. While the floating solar photovoltaic system is operating and being installed in several countries, the system is exposed to the risk in terms of structural safety due to the absence of the proper design guideline. In this paper, design loads suitable for the floating solar photovoltaic system are presented. Utilizing the existing reliable design standards such as ASCE 7-16 (ASCE 7-16 2016) and DNV-RP-C205 (DNV-RP-C205 2010), the appropriate design loads for the floating solar photovoltaic system are presented. The proper load combinations are also presented by putting wave load based on DNV standards (DNV-OS-C101 2015 and DNV-OS-C201 2015) into the load combinations in ASCE standards (ASCE 7-16 2016). We present the load combinations for the allowable stress design and load and resistance factor design, respectively.

Thermomechanical interactions in a transversely isotropic thermoelastic media with diffusion due to inclined load

  • Parveen Lata;Heena
    • Structural Engineering and Mechanics
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    • v.90 no.3
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    • pp.263-272
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    • 2024
  • This research deals with the study of two-dimensional deformation in transversely isotropic thermoelastic diffusion medium. This investigation integrates the effect of diffusion and thermal effects in transversely isotropic thermoelastic solids under inclined load. Inclined load is taken as linear combination of normal load and tangential load. Laplace and Fourier transformation techniques are employed to transform the physical domain and then transformed solutions are inverted with the aid of numerical inversion techniques. Concentrated and distributed load are considered to exemplify its utility. Graphical representation of variation in displacement, stresses, temperature and concentration distribution with distance is depicted by taking inclination at different angles. Some particular cases are studied.

Effect of the Combination of Point Loads on the Design Flexural Capacity for Fiber Reinforced Concrete Floor Slab (집중하중 조합에 의한 섬유 보강 콘크리트 바닥슬래브의 설계 휨 내력)

  • Lee, Jong-Han;Cho, Baik-Soon;Kim, Jung-Sik;Cho, Bum-Gu;Ki, Han-Sik
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.4 no.1
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    • pp.47-54
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    • 2016
  • In this study, the flexural capacity of fiber reinforced concrete floor slabs were evaluated using main design loads, racking and moving loads. Based on design standards and guidelines, the magnitude and loaded area of each load were determined, and its relationship was assessed. For the application of a single load, flexural capacity should be evaluated in the edge of a floor slab. In addition, the slab with thickness and concrete strength, greater than 180mm and 35MPa, respectively, sufficiently satisfied flexural capacity with a minimum of equivalent flexural strength ratio. The combination of racking loads required the largest equivalent flexural strength ratio to satisfy the flexural capacity of the floor slab. The combination of racking and moving loads showed equivalent flexural strength ratio smaller than the case of combination of racking loads, but larger than the application of single racking or moving loads. The results of this study indicated that the flexure of fiber reinforced concrete floor slabs should be designed using the combination of design loads.

Effect of thermal laser pulse in transversely isotropic Magneto-thermoelastic solid due to Time-Harmonic sources

  • Lata, Parveen;Kaur, Iqbal;Singh, Kulvinder
    • Coupled systems mechanics
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    • v.9 no.4
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    • pp.343-358
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    • 2020
  • The present research deals with the time-harmonic deformation in transversely isotropic magneto thermoelastic solid with two temperature (2T), rotation due to inclined load and laser pulse. Generalized theory of thermoelasticity has been formulated for this mathematical model. The entire thermo-elastic medium is rotating with uniform angular velocity and subjected to thermally insulated and isothermal boundaries. The inclined load is supposed to be a linear combination of a normal load and a tangential load. The Fourier transform techniques have been used to find the solution to the problem. The displacement components, stress components, and conductive temperature distribution with the horizontal distance are computed in the transformed domain and further calculated in the physical domain using numerical inversion techniques. The effect of angle of inclination of normal and tangential load for Green Lindsay Model and time-harmonic source for Lord Shulman model is depicted graphically on the resulting quantities.