Optimization Method for Unit Restarting during Power System Black-Start Restoration

Unit restarting is the basis of the whole restoration control and is also the guarantee for the fast network reconfiguration and load recovery during power system black-start restoration. In this paper, an optimization method for unit restarting during power system black-start restoration is studied. An hierarchical optimal strategy is proposed based on the layered feature of unit restarting which treated the unit restarting process as two-layer restoration process - the network-layer unit restarting and the plant-layer unit restarting, the hierarchical optimal model of unit restarting is built on analyzing the mutual influence of network-layer unit restarting and the plant-layer unit restarting, then the algorithm of backtracking was adopted to determine the best unit restarting sequences. The proposed optimization method can determine the restarting sequence of all the units, so it can eliminate the shortcomings of the previous in which a power plant is treated as a single unit or only one unit of each plant is considered, and it also realizes the coordinative optimization of network reconfiguration and plant unit restarting. The effectiveness of the proposed method is validated by the numerical results of a restoration example based on the New England 10-unit 39-bus power system.