Reconfigurable droop-based DC microgrids

This paper presents a mathematical formulation for loss minimization of reconfigurable and droop-based dc microgrids (dc MGs) during islanding. The objective is achieved by adjusting the droop settings of the distributed generators (DGs) and reconfiguring the topology of the islanded MG. The reconfiguration problem is formulated as a mixed-integer nonlinear optimization problem and solved via a metaheuristic technique: genetic algorithms (GAs). The proposed formulation takes into account: 1) the unavailability of a slack bus; 2) the droop controllability of DGs. The proposed model is tested on a six-bus islanded dc MG. The case studies demonstrate the effectiveness of the developed formulation in jointly optimizing the droop characteristics and MG topology for minimizing the power losses, and by product; improving the overall voltage profile.