Modeling And Solving Method Of Black-start Partitioning Schemes Optimization Based On Mathematical Programming

After the blackout accident,the power system needs a reasonable black start scheme to guide the restoration.How to quickly restore the power supply of the system is the core content of the black start scheme.Parallel restoration of multiple black start regions is conducive to reducing the complexity of subsystems,speeding up the black start process and improving the restoration reliability.In this paper,the modeling and solution of black start partition problem are studied in the following aspects.(1)The basic model of mixed integer linear programming for partition restoration optimization is established.Taking the maximum load recovery as the goal,and also considering the balance of system partition scale,the single objective function is established by using the weighting method;the AC power flow constraint is expressed as the DC power flow constraint by linearization,the connectivity constraint within the subsystem is established based on the Network Flow Theory,and the subsystem separation constraint is established by the variables of nodes in the subsystem input state;A mixed integer linear programming model for partition restoration optimization is established by integrating objective function and constraint set.IEEE 39 node system and118 node system are used as examples to solve the partition scheme.Through the analysis of the final zoning scheme,it is found that the partition optimization model has high efficiency and generality,can form reliable partition around the preset black start units,and can quickly solve the large-scale system to get the optimal solution of the objective function,which has guiding significance for the formulation of the actual black start partition scheme of the power system.(2)A multi-objective optimization method for system partition restoration based on normalized normal constraint method is proposed.This paper constructs a double objective function which considers the active power balance and the restoration cost balance among the sub-systems.Combined with the partition optimization constraint set proposed earlier,the black start partition restoration model of the double objective co-optimi-zation is established.A group of Pareto solutions are obtained by using the Normalized Normal Constraint method.The solution set is optimally selected based on the Variation Coefficient method,and the optimal partitioning scheme is finally obtained.The double objective optimization strategy can eliminate the subjective weight of objective function and the influence of dimension and order of magnitude difference on the result tendency,and get a more reasonable optimization result.(3)The partition optimization model considering the static security constraints of the system is established.Based on the weighted single objective function constructed above,considering the N-1 static security constraints,the static security flow constraints are established,and the normal operation conditions of each N-1 fault scenario are constrained.Combined with the connectivity constraints within subsystem and subsystems separation constraints,the partition optimization model considering the N-1static security constraints is established,and use mathematical programming algorithm to solve the model.Using IEEE 39 node standard system as an example,and the bearing capacity of the partition scheme for the contingency(N-1 disconnection)is analyzed,thus the conclusion of the rationality of the partition model is obtained.