Computational Modeling and Solution Methods for power Flow in Multilevel Grids

Based on the basic structure of transmission and distribution network, this chapter analyzes the output characteristics of dispatchable resources such as renewable energy, conventional generator set, interruptible load and energy storage device in detail, and establishes the basic model of each dispatchable resource participating in grid dispatching. A global model for the calculation of power flow of transmission and distribution collaboration is established. When calculating power flow of transmission network, the equivalent load of distribution network is processed as constant value; when power flow calculation of distribution network is required, the power grid is often processed as equivalent voltage source [1]-[2]. After the distributed power is injected into the distribution system, the distributed model is used to describe the transmission and distribution cooperative system, and the global power flow is calculated by alternating iteration between the transmission and distribution system. Finally, two kinds of solving algorithms are analyzed through a numerical example to verify that when the distributed power supply is connected to the distribution network, the appropriate A-node serial number is selected, which makes the power flow calculation convergence performance of the transmission and distribution collaborative system better, effectively meets the power flow calculation requirements of the transmission and distribution network in practical applications, and provides theoretical and model basis for the subsequent research on the collaborative optimization of transmission and distribution network.