The modal analysis method is utilized to study the influence of doubly-fed induction generator(DFIG)on electromechanical oscillations.On this basis,the small signal stability region(SSSR)of power systems with DFIG in ...The modal analysis method is utilized to study the influence of doubly-fed induction generator(DFIG)on electromechanical oscillations.On this basis,the small signal stability region(SSSR)of power systems with DFIG in injection space is evaluated and the corresponding relationship between SSSR boundary and electromechanical oscillations is analyzed.The effects of the locations of DFIG on SSSR are considered.It is found that the boundary of SSSR consists of several smooth surfaces,which can be approximated with hyper-planes in engineering application.With the integration of DFIG,SSSR becomes smaller,thus indicating the deterioration of the small signal stability of the system.The 11-bus system with four generators is used to illustrate the proposed method.展开更多
In a changing transition economy, Chinese government regulations that adopt the relatively simple bright line rule formula are enforceable in practice. Taking the early reform-oriented policies of the China Securities...In a changing transition economy, Chinese government regulations that adopt the relatively simple bright line rule formula are enforceable in practice. Taking the early reform-oriented policies of the China Securities Regulatory Commission(CSRC) as an example, we find that the CSRC did not consider local enthusiasm for reform when allocating IPO resources because of the high enforcement costs involved. We also find that CSRC listed company regulations were enforced due to the lower costs involved in verifying regulatory violations, and that listed companies that completed the reform process were given priority in public refinancing. We present empirical evidence supporting the theoretical basis for the hypotheses outlined above. We also conclude that companies that completed the reform process in 2005 were of significantly higher quality and that the SEO regulation did not affect stock market efficiency. These findings enhance our understanding of the efficiency of government regulation in a transition economy.展开更多
基金This work is supported by National Basic Research Program of China(973 Program)(No.2009CB219701).
文摘The modal analysis method is utilized to study the influence of doubly-fed induction generator(DFIG)on electromechanical oscillations.On this basis,the small signal stability region(SSSR)of power systems with DFIG in injection space is evaluated and the corresponding relationship between SSSR boundary and electromechanical oscillations is analyzed.The effects of the locations of DFIG on SSSR are considered.It is found that the boundary of SSSR consists of several smooth surfaces,which can be approximated with hyper-planes in engineering application.With the integration of DFIG,SSSR becomes smaller,thus indicating the deterioration of the small signal stability of the system.The 11-bus system with four generators is used to illustrate the proposed method.
基金supported by the National Natural Science Fund (grant no. 70602011)the National Social Science Fund (grant no. 08CJY009)+2 种基金the support we have received from the IAPHD Project of Nanjing Universitythe Institution of Accounting and Finance of Shanghai University of Finance and EconomicsResearch Project 985 of the Institution of Economic Transition and Development of Nanjing University
文摘In a changing transition economy, Chinese government regulations that adopt the relatively simple bright line rule formula are enforceable in practice. Taking the early reform-oriented policies of the China Securities Regulatory Commission(CSRC) as an example, we find that the CSRC did not consider local enthusiasm for reform when allocating IPO resources because of the high enforcement costs involved. We also find that CSRC listed company regulations were enforced due to the lower costs involved in verifying regulatory violations, and that listed companies that completed the reform process were given priority in public refinancing. We present empirical evidence supporting the theoretical basis for the hypotheses outlined above. We also conclude that companies that completed the reform process in 2005 were of significantly higher quality and that the SEO regulation did not affect stock market efficiency. These findings enhance our understanding of the efficiency of government regulation in a transition economy.
