Research on Equivalence of Receiving-Ending System for ±800kV UHVDC From Hami to Chongqing

With the increasing scale of the interconnected power networks, electromagnetic transient simulation of an actual power system usually takes long time by PSCAD/EMTDC; it leads to heavy calculation burden. The actual power system has to be divided into three parts, namely the internal system, the external system and the boundary system, and then the equivalent simplification of the external system network is carried out. The flow equivalent method is put forward for the adjacent nodes of power system that exists coupling, can overcome the deficiency of the tradition methods effectively. Through the comparison of power flow distributions, the short circuit current of key buses and transient behavior variations of power grid before and after the equivalence, it is proved that the proposed equivalence scheme is reasonable and the simplified system is practicable.