Research On Load Restoration Decision-making In Power System Restoration After Blackout

The ultimate target of power system restoration after blackout is to restore the power supply to consumers and reduce the outage loss. Therefore, the optimization decision-making of the load restoration scheme is of great significance to the formulation of reasonable system restoration scheme. Research on the load restoration in power system restoration has been done in this paper. A multi-objective optimization decision-making method for large-scale load restoration after network reconfiguration is proposed considering the requirements of load restoration. Meanwhile, the method of maximum restorable load calculation at a single node is proposed considering the influence of cold load characteristics on the load restoration.System frequency variation level together with recoverable load amount and load importance degree is introduced into the multi-objective optimization functions. The load restoration multi-objective optimization model is established,which considers the cold load characteristic constraint,the frequency-included steady-state power flow constraint,etc. The fast and elitist non-dominated sorting genetic algorithm is applied to obtain the optimization model established and the Pareto optimal solutions of load restoration scheme are obtained. The subjective and objective weights of each objective function are calculated by the unascertained rational number and information entropy method,the combined subjective and objective weight is calculated by the least square method,and the grey incidence decision-making model is employed to finally obtain the best solution. The example of New England 10-unit 39-bus system verifies the effectiveness of the proposed method.According to the optimization of single node load model, the model for calculating restoration amount of cold load is established based on the influence of such three factors as environment temperature, power outage time and temperature controlled load proportion on the cold load pickup. The generalized model of load restoration with the objective of maximizing the recoverable load amount and the practical constraints of transient frequency is established by combining two types of bus load classification which are electricity body and start-up characteristics of load. The steady state and transient state process of load restoration are studied by the expanded flow calculation, transient energy function calculation and power system analysis software PSD-BPA simulation. The reasonableness of the proposed method is verified by simulation results of power system.