The Experts below are selected from a list of 249 Experts worldwide ranked by ideXlab platform

B H Khan - One of the best experts on this subject based on the ideXlab platform.

  • stability improvement of Power system by simultaneous ac DC Power Transmission
    Electric Power Systems Research, 2008
    Co-Authors: H Rahman, B H Khan
    Abstract:

    Abstract This paper presents a concept of improving the transient stability of Power system by simultaneous AC–DC Power Transmission through a Transmission line. A double circuit long Transmission line is converted to simultaneous AC–DC line for feasibility study. Loss of synchronism is prevented by quickly producing sufficient decelerating energy to counteract accelerating energy gained during fault and subsequently due to loss of line after clearing the fault. Fast controllability and modulation of DC component is utilized to achieve this feature. The system under consideration is found to remain stable under transient condition up to Transmission angle of 80°. Simulation study on PSCAD/EMTDC is carried out to validate the concept.

  • Power upgrading of Transmission line by combining ac DC Transmission
    IEEE Transactions on Power Systems, 2007
    Co-Authors: H Rahman, B H Khan
    Abstract:

    Long extra high voltage (EHV) ac lines cannot be loaded to their thermal limits in order to keep sufficient margin against transient instability. With the scheme proposed in this paper, it is possible to load these lines very close to their thermal limits. The conductors are allowed to carry usual ac along with DC superimposed on it. The added DC Power flow does not cause any transient instability. This paper presents the feasibility of converting a double circuit ac line into composite ac-DC Power Transmission line to get the advantages of parallel ac-DC Transmission to improve stability and damping out oscillations. Simulation and experimental studies are carried out for the coordinated control as well as independent control of ac and DC Power Transmissions. No alterations of conductors, insulator strings, and towers of the original line are needed. Substantial gain in the loadability of the line is obtained. Master current controller senses ac current and regulates the DC current orders for converters online such that conductor current never exceeds its thermal limit

Gao Liying - One of the best experts on this subject based on the ideXlab platform.

  • practice of energy conservation design for uhv DC Power Transmission project
    Power system technology, 2011
    Co-Authors: Gao Liying
    Abstract:

    Ultra high voltage DC(UHVDC) converter station possesses following features: large-scale,huge quantity of equipments and large building area,so energy conservation design of UHVDC project has demonstrative effect.In this paper the design idea and scheme in adopting high-capacity and energy conservation equipments which take less construction site,optimizing station site and plan layout,adopting energy conservation schemes in the design of buildings and accessory system are presented.

  • a survey on demonstration of uhv Power Transmission by state grid corporation of china in the year of 2005
    Power system technology, 2006
    Co-Authors: Gao Liying
    Abstract:

    At the end of 2004, State Grid Corporation of China (SGCC) put forward the strategic objective of developing UHV Power Transmission. Here, the demonstration process of developing UHV Power Transmission in China by SGCC since 2005 and the significance and necessity of carrying out such demonstration, the selection of demonstration project for UHV AC Power Transmission and the demonstration process of UHV DC Power Transmission from Xiluodu and Xiangjiaba hydroPower stations in Jinsha River valley, as well as the. research results on the key technologies of UHV Power Transmission, for instance the selection of voltage class for UHV Power Transmission, environment protection, AC over-voltage, etc., are presented. Above-mentioned substances show that the research and demonstration processes are scientific and democratic, the results of research and demonstration are reasonable and reliable, and these results can give strong and vigorous supports for the construction of domestic UHV Power Transmission.

W U Xiaochen - One of the best experts on this subject based on the ideXlab platform.

H Rahman - One of the best experts on this subject based on the ideXlab platform.

  • stability improvement of Power system by simultaneous ac DC Power Transmission
    Electric Power Systems Research, 2008
    Co-Authors: H Rahman, B H Khan
    Abstract:

    Abstract This paper presents a concept of improving the transient stability of Power system by simultaneous AC–DC Power Transmission through a Transmission line. A double circuit long Transmission line is converted to simultaneous AC–DC line for feasibility study. Loss of synchronism is prevented by quickly producing sufficient decelerating energy to counteract accelerating energy gained during fault and subsequently due to loss of line after clearing the fault. Fast controllability and modulation of DC component is utilized to achieve this feature. The system under consideration is found to remain stable under transient condition up to Transmission angle of 80°. Simulation study on PSCAD/EMTDC is carried out to validate the concept.

  • Power upgrading of Transmission line by combining ac DC Transmission
    IEEE Transactions on Power Systems, 2007
    Co-Authors: H Rahman, B H Khan
    Abstract:

    Long extra high voltage (EHV) ac lines cannot be loaded to their thermal limits in order to keep sufficient margin against transient instability. With the scheme proposed in this paper, it is possible to load these lines very close to their thermal limits. The conductors are allowed to carry usual ac along with DC superimposed on it. The added DC Power flow does not cause any transient instability. This paper presents the feasibility of converting a double circuit ac line into composite ac-DC Power Transmission line to get the advantages of parallel ac-DC Transmission to improve stability and damping out oscillations. Simulation and experimental studies are carried out for the coordinated control as well as independent control of ac and DC Power Transmissions. No alterations of conductors, insulator strings, and towers of the original line are needed. Substantial gain in the loadability of the line is obtained. Master current controller senses ac current and regulates the DC current orders for converters online such that conductor current never exceeds its thermal limit

Shu Lichun - One of the best experts on this subject based on the ideXlab platform.

  • external insulation of 800 kv uhv DC Power Transmission lines in china
    Power system technology, 2006
    Co-Authors: Shu Lichun
    Abstract:

    In China, the constructions of multi ±800 kV UHVDC Transmission projects are planned. Because the experiences in design and operation of such UHVDC Transmission line home and abroad are absent, the selection of external insulation of these projects under high altitude, contamination, ice coating, snow coating, acid rain and acid fog conditions is one of the key problem to be faced with. On the basis of existing research results home and abroad, the particularity in external insulation selection of domestic UHVDC Transmission lines, the effects of high altitude, contamination, ice coating, snow coating, acid rain and acid fog on discharge characteristics of insulators for domestic UHVDC Transmission lines as well as the discharge characteristics of long air gap under high altitude are expounded. It is pointed out that high altitude, contamination, ice coating, snow coating, acid rain and acid fog are important factors affecting the electrical performance of insulators, air gaps and the selection of external insulation of UHVDC Transmission lines, and it is proposed that when existing methods are used to select the external insulation of UHVDC Transmission lines, the effects of high altitude, contamination, ice coating, snow coating, acid rain and acid fog must be considered and these methods should be modified.