Optimisation of network reconfiguration based on a two-layer unit-restarting framework for power system restoration

An optimisation method of network reconfiguration is proposed by introducing a two-layer unit-restarting framework for power system restoration. The unit restarting during the network reconfiguration is treated as a two-layer restoration process - network-layer unit restarting and plant-layer unit restarting. Based on the two-layer framework, the optimisation of the network reconfiguration is modelled as a multi-objective optimisation problem, in which the network-layer unit restarting, the plant-layer unit restarting and restoration of the important loads are separately modelled as three optimisation sub-problems with their own models and solving algorithms. The lexicographic optimisation method is then used to solve the multi-objective optimisation problem by integrating the solving processes of the three sub-problems. The proposed optimisation method of network reconfiguration can determine the restarting sequence of all the units and realise the coordinative optimisation of the unit restarting and restoration of the important loads. The effectiveness of the proposed method is validated by the numerical results of a restoration example based on the New England 10-unit 39-bus power system.