The Problems Emerging in Developing the Huge Power Grid

In this paper the problems emerging during the process of developing the huge power grid are presented and discussed respectively. The first is the short circuit current which improves with the installation capacity. So in order to limit the short circuit current some concerning methods are taken while on the contrary some methods sacrifice the reliability of the whole power system. Second the power flow in the power grid is not easy to judge immediately so it will make the dispatch under the fault situation becomes difficult and more of the fault may be induced by the not proper dispatching. Third problem is the criterion of the N-l. Under fault situation this criterion can be changed to N-K. The fourth problem is of the second side equipment. The telecommunication board itself can make four or even more of the transmission lines to trip though the system on the high voltage side can fulfill the N-l criterion.