Hierarchical Coordinated Optimisation of the Restoration Decision-Making for Multi-Voltage-Level Power Systems With Wind Power Integration

In power system restoration (PSR), networks with various voltage levels have different decision-making constraints and restoration characteristics. Specifically, the restoration plan for the lower voltage level network is more adaptable to uncertainty of wind power output, owing to its greater flexibility. First, the restoration scheme decision-making is divided into two parts for the main network level (MNL) and the regional network level (RNL) respectively, according to the voltage levels. Second, a hierarchical coordinated optimisation model is established based on a two-stage framework. In the first stage, the plants/lines restoration sequence of the MNL and the subsystem partitioning scheme are determined. Furthermore, the plants/lines restoration sequence of the RNL and the restoration power scheduling scheme of the MNL and RNL are obtained in the second stage of optimisation, which can be flexibly adjusted to adapt to uncertain wind power outputs. The coordination and allocation of frequency regulation resources across subsystems are considered. Finally, the nested column and constraint generation algorithm is applied to solve the two-stage robust model. Case studies using the IEEE standard and a provincial system in China show that the algorithm converges in 2–3 iterations. Compared to non-hierarchical approaches, the proposed method improves cumulative restored energy by 2% and 5.3% in case 1 and case 2, respectively, while maintaining robustness against wind power uncertainty, highlighting its effectiveness in multi-level PSR.