13 - Hierarchical service restoration for active distribution networks based on alternating direction method of multipliers

Abstract

Chapter 13 proposes a hierarchical service restoration scheme to obtain service restoration plans based on the alternating direction method of multipliers (ADMMs). As a critical part of self-healing, service restoration aims to restore outage areas with minimal unsupplied demands. With the increasing complexity and size of active distribution networks, distribution system operators face a more complicated service restoration problem. Thus, it is important to obtain optimal service restoration plans and reduce computational complexity. To achieve this goal, a hierarchical service restoration scheme is proposed to obtain service restoration plans based on the ADMMs. Firstly, the optimal service restoration problem is formulated as an mixed-integer nonlinear programming (MINLP) model considering the switching sequence, distributed generation units, and controllable loads. Then, the MINLP model is transformed into an mixed-integer linear programming model by using linearization techniques, which is decomposed and solved using the proposed ADMM-based algorithm in a hierarchical manner. In the proposed scheme, each zone of the ADN has a local service restoration controller solving its subproblem with information from a central service restoration controller. The central controller solves a global coordination problem with information from all the zones. The proposed hierarchical service restoration strategy can obtain optimal service restoration plans and reduce computational complexity. By using the proposed hierarchical scheme, the computation time can be reduced substantially for large-scale active distribution networks.