The traditional tie-line schedule is entirely based on the electricity transaction

hence it is loosely coupled with power grid operation all along and relatively independent from the generation scheduling. These cause difficulties in adjusting tie-line schedule and lack of capacity in global allocation of resources. In face of these problems

a hierarchical tie-line schedule model based on network-wide coordination is proposed by resorting to the existing tie-line planning. The upper model gets the ideal tie-line schedule through the economical dispatch constrained by the whole network security. The lower model uses the ideal tie-line schedule as the optimization objective

and takes electricity transactions as constraints to achieve the tie-line schedule. This model has achieved automatic preparation and flexible adjustment of tie-line scheduling

while providing an available manner that combines the schedule with the grid operating state. The proposed algorithm is applied to the tie-line schedule of Central China power grid

while the comparison between the proposed method and the traditional method showing the correctness and effectiveness of the proposed algorithm.