Excitation system is one of the significant elements affecting the dynamic performance of electric power systems. The power engineering as area of science and industry is subjected to rapid modernization, which is cau...Excitation system is one of the significant elements affecting the dynamic performance of electric power systems. The power engineering as area of science and industry is subjected to rapid modernization, which is caused by technological progress. However, not all elements of the power system are developing simultaneously. The old type of elements sometimes is sufficient to adapt old system to the new operational conditions. The work developed and proposed in this paper deals with analysis of possible optimization of synchronous generator＇s excitation system. Authors examined influence of excitation system＇s parameters to the dynamics of transient processes in the power system. Authors investigated optimal parameters of excitation system of the Kegums hydro power plant. For optimization of parameters objective functions were used. The problem of the mutual influence of excitation systems of neighbor power plants was investigated. Investigation of transient processes using developed model proved that optimization of excitation parameters improves efficiency of regulation of excitation system, damping of active power oscillation and in some cases can prevent out-of-step condition.展开更多
The present paper studies the sources of economic growth and the nature of structural change in the Chinese economy from 1987 to 2008. Using a methodology that evaluates the contribution o fan industry to economic gro...The present paper studies the sources of economic growth and the nature of structural change in the Chinese economy from 1987 to 2008. Using a methodology that evaluates the contribution o fan industry to economic growth, the present paper shows that the post-2000 subperiod marked an increased reliance on the services sector as a source of growth in the Chinese economy. Much of the acceleration in real GDP or aggregate labor productivity growth in China in the post-2000 subperiod compared to the pre-2000 period can be traced to an increased contribution from service-producing and high-technology exporting manufacturing industries. The evidence indicates that the Chinese economy has been rebalancing toward domestic consumption and shifting its export sector toward high- technology manufacturing industries.展开更多
文摘Excitation system is one of the significant elements affecting the dynamic performance of electric power systems. The power engineering as area of science and industry is subjected to rapid modernization, which is caused by technological progress. However, not all elements of the power system are developing simultaneously. The old type of elements sometimes is sufficient to adapt old system to the new operational conditions. The work developed and proposed in this paper deals with analysis of possible optimization of synchronous generator＇s excitation system. Authors examined influence of excitation system＇s parameters to the dynamics of transient processes in the power system. Authors investigated optimal parameters of excitation system of the Kegums hydro power plant. For optimization of parameters objective functions were used. The problem of the mutual influence of excitation systems of neighbor power plants was investigated. Investigation of transient processes using developed model proved that optimization of excitation parameters improves efficiency of regulation of excitation system, damping of active power oscillation and in some cases can prevent out-of-step condition.
文摘The present paper studies the sources of economic growth and the nature of structural change in the Chinese economy from 1987 to 2008. Using a methodology that evaluates the contribution o fan industry to economic growth, the present paper shows that the post-2000 subperiod marked an increased reliance on the services sector as a source of growth in the Chinese economy. Much of the acceleration in real GDP or aggregate labor productivity growth in China in the post-2000 subperiod compared to the pre-2000 period can be traced to an increased contribution from service-producing and high-technology exporting manufacturing industries. The evidence indicates that the Chinese economy has been rebalancing toward domestic consumption and shifting its export sector toward high- technology manufacturing industries.
