Effects of the excitation system parameters on power system transient stability studies

The excitation system parameters of large synchronous generators have great effects on power system stability studies. It is pointed out in this paper that by using the excitation system parameters identified from the field data by means of modern identification technology can represent the actual responses of the excitation system more accurately. Therefore, it is necessary to adopt the parameters identified from the field data in real power system stability studies. The comparison results of three kinds of excitation system models, i.e. the electromagnetic force E_q^\´ constant model, typical parameter model, and real model identified from field data, are also presented. The results demonstrate that the adjusting effects may be exaggerated by using the E_q^\´ constant model in power system stability studies to represent the conventional excitation system with time constant t=0.5", conceal the stability risk, while for fast response excitation system, the transient stability limits may be reduced by using E_q^\´ constant model, and thus conceal the potential of stability limits. The optimization of the excitation system parameters and their effects on power system transient stability studies are also given in this paper