The Experts below are selected from a list of 408 Experts worldwide ranked by ideXlab platform

Pan Wenxia - One of the best experts on this subject based on the ideXlab platform.

  • calculation and analysis of grounding body of typical tower foundation for UHV Power Transmission
    Power system technology, 2013
    Co-Authors: Pan Wenxia
    Abstract:

    To research the impacts of artificial horizontal grounding body on grounding resistance and current divergence of tower foundation for UHV Power Transmission,based on CDEGS software a simulation model for typical tower foundation for UHV Power Transmission and its artificial horizontal grounding body is built,and simulation computation of resistance-reducing rate and current divergence ratio under different soil resistivity,different lengths of horizontal grounding body and horizontal grounding body with different number of electrodes is performed.Simulation results show that the effect of horizontal grounding body on grounding resistance reduction of tower foundation for UHV Power Transmission is not so evident,so the effect of natural grounding body should be fully utilized to the foundation grounding of towers for UHV Power Transmission.Current densities in foundation grounding bodies of three typical towers for UHV Power Transmission are calculated,and calculation results show that the current density in vertical single-pile grounding body is the maximum.When the grounding current is 10A,the maximum current density appears at the bottom segment of the grounding body and the maximum current density at non-bottom segment of the grounding body is 1.156 A/m.

Fan Jianbin - One of the best experts on this subject based on the ideXlab platform.

  • summary of experimental study on switching impulse flashover characteristics of typical air gaps in ehv UHV Transmission systems
    Power system technology, 2011
    Co-Authors: Fan Jianbin
    Abstract:

    In the design of EHV/UHV Power Transmission projects,the selection of air gaps is very important for it impacts on the sizes of Transmission towers and distances among various electrified constructional elements within substations or converter stations.Rational design of air gap not only concerns secure and stable operation of Power system,but also direcly bears up on construction cost of the project.Generally speaking,the air gap to withstand switching overvotlage needs maximum air gap length than those withstanding Power frequency overvoltage,DC overvoltage or lightning surge,thus the switching impulse flashover characterisitics of typical air gaps of Transmission tower,and those in substations and converter stations is one of the important factors impacting on security and economy of Transmission projects,and is also the main foundation in the design of EHV/UHV AC/DC Transmission projects.The discharging characteristic of air gap under switching overvoltage is related to such factors as the form of electrode,distance between electrodes,the waveform of the applied votlage and so on.To provide reference for more in-depth researches in future in this field,the experimental studies on switching impulse flashover characteristics of air gaps home and abroad are summarized,including various switching impulse flashover characteristics and factors impacting the characteristics.

Huiru Zhao - One of the best experts on this subject based on the ideXlab platform.

  • risk evaluation of a UHV Power Transmission construction project based on a cloud model and fce method for sustainability
    Sustainability, 2015
    Co-Authors: Huiru Zhao, Nana Li
    Abstract:

    In order to achieve the sustainable development of energy, Ultra High Voltage (UHV) Power Transmission construction projects are being established in China currently. Their high-tech nature, the massive amount of money involved, and the need for multi-agent collaboration as well as complex construction environments bring many challenges and risks. Risk management, therefore, is critical to reduce the risks and realize sustainable development of projects. Unfortunately, many traditional risk assessment methods may not perform well due to the great uncertainty and randomness inherent in UHV Power construction projects. This paper, therefore, proposes a risk evaluation index system and a hybrid risk evaluation model to evaluate the risk of UHV projects and find out the key risk factors. This model based on a cloud model and fuzzy comprehensive evaluation (FCE) method combines the superiority of the cloud model for reflecting randomness and discreteness with the advantages of the fuzzy comprehensive evaluation method in handling uncertain and vague issues. For the sake of proving our framework, an empirical study of “Zhejiang-Fuzhou” UHV Power Transmission construction project is presented. As key contributions, we find the risk of this project lies at a “middle” to “high” level and closer to a “middle” level; the “management risk” and “social risk” are identified as the most important risk factors requiring more attention; and some risk control recommendations are proposed. This article demonstrates the value of our approach in risk identification, which seeks to improve the risk control level and the sustainable development of UHV Power Transmission construction projects.

  • risk evaluation on UHV Power Transmission construction project based on ahp and fce method
    Mathematical Problems in Engineering, 2014
    Co-Authors: Huiru Zhao
    Abstract:

    Ultra high voltage (UHV) Power Transmission construction project is a high-tech Power grid construction project which faces many risks and uncertainty. Identifying the risk of UHV Power Transmission construction project can help mitigate the risk loss and promote the smooth construction. The risk evaluation on “Zhejiang-Fuzhou” UHV Power Transmission construction project was performed based on analytic hierarchy process (AHP) and fuzzy comprehensive evaluation (FCE) method in this paper. After the risk evaluation index system was built, the AHP was used to determine the weights of risk indicators, and the FCE method was to perform the risk evaluation. The evaluation result shows that (1) “Zhejiang-Fuzhou” UHV Power Transmission construction project has moderate risk, which indicates the occurrence probability of project risk is medium and the risk occurrence will cause general loss for project, (2) “society risk” has the highest level, and the next is “policy and law risk,” “technique risk,” “natural environmental risk,” and “Management risk,” respectively, and it should keep main eye on the social risk, policy and law risk, and technique risk. Finally, according to the risk evaluation result, the specific risk control recommendations were proposed for the smooth construction of this project.

Zhao Liang - One of the best experts on this subject based on the ideXlab platform.

  • research on modes of connecting bulk Power bases to Power grids by UHV Transmission systems
    Power system technology, 2009
    Co-Authors: Zhao Liang
    Abstract:

    The development and operation situation of ultra high voltage(UHV) Transmission systems home and abroad are described in brief,the reasonability and feasibility of directly connecting bulk Power base to Power grid by UHV Transmission system are analyzed,and the economy of the two connecting modes,i.e.,directly connecting bulk Power base with UHV Transmission system and connecting bulk Power base to Power grid via twice step-up,are compared.Comparison conclusion shows that how to connect bulk Power base with UHV Power Transmission system should be determined according to actual conditions,different grid-connecting modes should be adopted under different conditions.

Yang Fengli - One of the best experts on this subject based on the ideXlab platform.

  • selection of calculation model for steel tubular tower of UHV Power Transmission line
    Power system technology, 2010
    Co-Authors: Yang Fengli
    Abstract:

    Based on the simplified model of integral space truss,the member stress of UHV steel tubular tower is calculated by bar elements.Due to the assumption that the element only sustains axial force while the action of bending moments at its both ends are neglected,there are diffenrences between calculation results and actual conditions.Taking the steel tubular tower for 1 000 kV Power Transmission project from South Anhui to Shanghai,in which the double circuits on the same tower mode is adopted,as analysis object and by use of three computation models,namely the bar element model in general program for tower design,the beam-bar and beam element models in general program for finite element computation ANSYS,the static and dynamic performances of tubular tower are calculated and compared.Calculation result comparison shows that the axial force of legs and natural vibration of the tower are almost the same;the bar end bending moments respectively calculated by beam-bar hybrid element model and beam element model are similar.Thus,it is recommended that the stress of steel tubular tower for UHV Power Transmission project can be calculated by integral space truss method in beam-bar hybrid element model,and in the design of the steel tubular tower the effects of bending moment at member end on the stress of tower leg should be considered.