Transmission network structure optimization scheduling method and system

The invention discloses a power transmission network structure optimization scheduling method and system. The method comprises the steps of: taking the minimum output cost of a power transmission network unit as an overall objective function, dividing a power transmission network structure according to connection branches between regions, and constructing a power transmission network scheduling model for each region; performing hierarchical division after performing linear optimization processing on the power transmission network scheduling model, and taking a target quantity of a virtual load in an upper-layer model and a response quantity of a virtual generator in a lower-layer model as coupling variables between hierarchies; and introducing a penalty function to perform relaxation processing on the coupling constraint between the hierarchies, determining an objective function and a constraint condition corresponding to each region so as to solve the optimized power transmission network scheduling model, an