Research On Multi-objective Optimal Power Flow For Hybrid AC/DC Systems With VSC-HVDC Considering Security Constraints

In recent year,as a new generation of direct current transmission technology,VSC-HVDC has developed rapidly.And the requirements of system operation are also increasing.For this purpose,MOPF is suitable for the operation analysis of hybrid AC/DC system,since it can coordinate multiple optimization objectives.Meanwhile,with the continuous expansion of the scale of the power system,the system is increasingly running close to its stability limits.SC-MOPF ensures the security and stability of power system,due to it can adjust the opreating state within the time limit that the system can endure in the contingency state.First,the mathematical model of MOPF problem is built to coordinate the economy,environment,and safety benefits for hybrid AC/DC grids,based on VSC-HVDC steady-state model.Furtherly,the model of SC-MOPF problem is built.Then,a two-stage approach for optimization and decision is presented,based on the hybrid AC/DC grids and the MOPF model.In the first stage,PBCE-IBEA algorithm,which uses the parallel computing embed into MOEAs,is used for finding Pareto-optimal solutions;in the second stage,FCM clustering and GRP method is applied to choose the best compromise solutions,providing references to operators.Particularly,the correction control methods are adopted and the contingencies are filtered based on the regression learning algorithm,and thereby the Pareto-optimal solutions satisfying security constrains are obtained in the first stage for solving the SC-MOPF problem.Finally,the proposal is illustrated by solving MOPF and SC-MOPF problems in modified IEEE 14-bus,118-bus,and 300-bus test system.The effectiveness of the proposed approach is verified.