The research on distributed dynamic power flow based on asynchronous iteration mode considering frequency change

In modern power system, power systems are being interconnected into a unified system. The structure of the power grid is more and more complex, and the relation between different regional power grids is more closed. In order to achieve a joint power grid scheduling, incident handling and fault simulation, objectively, the control centers are required to use distributed algorithm. But the distributed Energy Management System (EMS) and Dispatcher Training Simulator (DTS) used now are not mature and the frequency changes are not considered in the distributed algorithms. This makes impossible to obtain an accurate simulation of the actual power system operation status in the distributed EMS/DTS. Because the dynamic flow algorithm can reflect the actual system more exactly, a new method called distributed dynamic power flow based on asynchronous iteration mode considering frequency change is proposed in this paper. The whole idea of the algorithm is given. The generator unit in dynamic power flow, considering frequency changes, can be modeled in coordinate layer and used to calculate frequency changes and the power sent to the network. The network modeled in coordinate layer and subsystems, is used to calculate power flow and unbalance power of the interconnected system. By a dozen times iterative solution between generator unit and network unit, the unbalanced power are distributed in generator and load nodes finally. In this article, we take the IEEE 9 node system as an example to authenticate this method. The simulation results are the same as the real ones hence showing that the new algorithm is real and effective.