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[attachment=4529]
Power Upgrading of Transmission Line
by Combining AC DC Transmission
H. Rahman and B. H. Khan, Senior Member, IEE
abstract
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 load ability 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. Index Terms Extra high voltage (EHV) transmission, flexible ac transmission system (FACTS), power system computer-aided design (PSCAD) simulation, simultaneous ac dc power transmission.
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[attachment=5268]
AC and DC Power Transmission,1991. International Conference on
Digital simulation of HVDC transmission and its correlation to simulator studies
Abstract
In order to investigate the behaviour of HVDC transmission in a power system, suitable simulation models are required. A detailed commutation model with simulation of the thyristor bridges, while very precise, requires considerable time for calculation. Simplified models, on the other hand, do not always provide sufficiently accurate results. Simplified and detailed HVDC simulation models are described and compared. In order to provide a yardstick for comparison, the HVDC Benchmark model study of the FGH analog simulator at Mannheim-Rheinau was used as a reference. The NETOMAC digital simulation program which was employed for all calculations, is a powerful and flexible tool by means of which practically all problems of electrical energy transmission including control algorithms can be investigated. The variable time step of NETOMAC is of particular relevance for investigation of HVDC transmission and static VAr compensators thus ensuring that the continuity conditions are always satisfied while a thyristor is fired
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PLEASE SEND ME THE DETAILS ABOUT THE TOPICS
LOADMONITORING
DISTRIBUTION SYSTEM RELAYING
PROTECTION OF TRANSMISSION SYSTEM BY USING THE GLOBAL POSITIONIG SYTEM
BIOMASS FUELLED POWER PLANT
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hello,
i want full report on "POWER UPGRADING OF TRANSMISSION LINE BY COMBINING AC-DC TRANSMISSION".so pls anyone post the full report
