Dc microgrid clusters and method of controlling the system

Abstract

A power generation system for operating a direct current (DC) microgrid (MG) cluster comprises a DC MG cluster including a plurality of DC MGs interconnected via tie-lines for transferring electric power based on bus voltage differences. Each DC MG includes a plurality of distributed generation units (DGUs) supplying local loads. The power generation system also includes a distributed hierarchical control system comprising a primary controller, a secondary controller, and a tertiary controller controls the operation of the DC MG cluster. A two-layered cyber network supports communication between DGUs and MGs via lower and upper layers, respectively, with pinning links enabling inter-layer communication. The tertiary controller minimizes total generation cost, the secondary controller ensures optimal power allocation, and the primary controller performs droop control. A user-defined control parameter sets a predefined upper limit for convergence time, enabling prescribed performance-based predefined time (PP-PDT) control across the DC MG cluster.