System and method for distributed control of a direct current microgrid

Abstract

A method and a system for distributed control of a direct current (DC) microgrid having a plurality of distributed generators (DGs) coupled to a DC bus through a plurality of converters includes measuring local voltage and current of each DG and computing, via a distributed voltage observer, an estimated average bus voltage using neighbor information exchanged over a communication network. Incremental cost (IC) consensus and bus voltage regulation errors are determined and constrained within time-varying performance bounds using an adjustable prescribed performance function (APPF). Control inputs are computed for convergence within a fixed time independent of initial conditions. An event-triggered communication mechanism minimizes data exchange by transmitting updates only when a triggering condition is satisfied. The droop references of the converters are updated to equalize DG ICs within power limits to regulate the estimated average bus voltage of the microgrid towards the nominal bus voltage.