Generalized shipboard microgrid power flow incorporating hierarchical control

Abstract

Modern shipboard microgrids (SMGs) incorporating distributed energy resources (DERs) enhance energy resilience and reduce carbon emissions. However, the hierarchical control schemes of DERs bring challenges to the traditional power flow methods. This paper devises a generalized three-phase power flow approach for SMGs that integrate hierarchically controlled DERs. The main contributions include: (1) a droop-controlled three-phase Newton power flow algorithm that automatically incorporates the droop characteristics of DERs; (2) a secondary-controlled three-phase power flow method for power sharing and voltage regulation; and (3) modified Jacobian matrices to incorporate various hierarchical control modes. Numerical results demonstrate the effectiveness of the devised approach in both balanced and unbalanced three-phase hierarchically controlled SMG systems with arbitrary configurations.