Research On Load Restoration Under Different Reconfiguration Schemes

Load recovery, the final stage of power system black-start restoration is investigated in this paper. With the consideration of the diversity of load type in actual systems, the loads are divided into the industry load, the commercial load, the residential load, the government load, the agricultural load, and the public entrepreneurial load. Different locations and types of loads have different impacts on the system frequency because of the different load characteristics. Even if the same capacity is restored, the influence on the grid will be different. So, when load recovery is researched based on the reconfigured network, this paper represented each kind of load characteristic with a synthesized power-function load model. The maximized amount of the load restoration is taken as the optimization objective function to obtain the optimal load recovery plan. Furthermore, the full load recovery in the late restoration process of a blackout power system is also investigated to build an optimization method for determining the load restoration plans from the ending state of network reconfiguration. By dividing the full load recovery process into several sequential restoration stages, the maximized amount of the load restoration in each stage is taken as the objective function, with consideration of the diversity of load types and outage loss at each load bus, the optimization of the load restoration is treated as a0-1knapsack problem, and the backtracking algorithm is used to solve it. Considering that power outage loss of users is a great portion of accident loss, the differences of the load types and the power outage loss on different buses are taken into account in the optimized model for load recovery and the load restoration strategies are designed with a balance between the rapid recovery of urgency load and outage costs of different types of users. A comparison analysis is carried out to evaluate the differences of load restoration effects on the different reconfigured networks. Finally, the IEEE30bus test system is employed to verify the effectiveness of the proposed optimized method for load restoration.