Fast solution method for evaluation of long-term dynamic processes in power systems with provision for island operation

1991 ◽  
Vol 21 (3) ◽  
pp. 217-224 ◽  
Author(s):  
Dragan P. Popović ◽  
Miodrag B. Djukanović
Author(s):  
Mikhail V. Gordin ◽  
Valery I. GUROV ◽  
Anton N. Varyukhin ◽  
Alexander V. Geliev ◽  
Elena V. SHCHERBAKOVA

This article presents Russia’s main achievements of over the past 65 years in the development of an advanced scientific and technical groundwork for the introduction of hydrogen as a fuel in various energy systems. On the basis of the obtained world-class results, the authors argue for the necessity of creating a Center for Hydrogen Innovative Development (CVIR) with the decisive participation of enterprises with real experience in obtaining liquid hydrogen (H2l) with the possibility of its long-term storage. A concept has been formulated for the development of breakthrough technological solutions for the widespread use of hydrogen as an efficient and environmentally friendly (without the formation of carbon oxides) fuel in various power systems within the framework of the CVIR. In particular, the strategic direction of the CVIR project was developed in order to create a developed infrastructure for the reliable provision of vehicles with the required amount of fuel in a limited period of time. This can be achieved by applying the method of cryogenic filling of transport cylinders, taking into account the real properties of hydrogen in the ultra-high pressure region (70 MPa and above). The results have revealed possibilities for further building up the advanced scientific and technical groundwork for the broad promotion of hydrogen in the energy complex of Russia, which is presented in the CVIR project. In addition, the authors have compared the developed technologies with foreign analogues.


Author(s):  
Peter Carter ◽  
Douglas L. Marriott

Design for cyclic loading is emerging as a key question for next generation power systems. Recent developments in techniques for cyclic stress analysis have significant implications for high temperature design. In the same way that limit load analysis is now being used to overcome the difficulties and guesswork of stress classification for steady primary loads, so shakedown and ratcheting analysis can eliminate the more difficult problems of stress classification for cyclic loads. The paper shows how reference stresses defined for shakedown and ratcheting provide rapid and conservative information for design against rupture and creep damage, deformation and strain accumulation, and ratcheting. These techniques will provide additional insights to designers and are likely to augment rather than replace, existing options. These ideas have existed in the research literature for some time, but have now become more accessible by the general industry with a new analysis technique in a commercial finite element code. Examples are given which demonstrate the methodology for nozzles having non-thermal secondary stresses, and prediction of long-term distortion in thermal shock problems.


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