Stochastic Expansion Planning of AC/DC Transmission Network Based on Benders Decomposition

In this paper, the random scenario simulation method was employed to describe the stochastic outage accidents of units and transmission lines as well as load prediction errors. Additionally, a stochastic expansion planning method of AC/DC hybrid transmission network was proposed based on Benders decomposition. Firstly, the comprehensive cost objectives of AC/DC transmission line investment cost, loss of load cost and system operation cost were established. The mixed integer linear programming model of AC/DC hybrid transmission network was decomposed into the main planning problem and the subproblems of reliability verification and economic scheduling through Benders decomposition. The simulation results of the six-bus system and the modified IEEE-118 bus system demonstrate that, in comparison to the AC transmission system, expanding the DC transmission line yields greater cost savings. The selection of an AC/DC transmission line can enhance the controllability and economy of the transmission power flow, thereby reducing load loss in the DC line.