Implementation of Finite Control State Model Predictive Control with Multiple Distributed Generators in AC Microgrids

Abstract

Microgrids enable high insertion of renewable energy sources in the main electricity grid, however advanced control is required to coordinate the powerflow between these sources and the grid. Model predictive control has become lately very attractive for power electronics applications, especially in the control of inverters. This includes grid-connected and islanded inverters as well as those creating microgrids systems. The finite control set model predictive controller allows the control to be implemented in a series of discrete time steps for converter control. The finite control set model predictive control method is implemented in both inter-connected and islanded modes of operation for multiple distributed generators in this article, where each generator has its own controller. In the grid-connected mode, the focal control is of power contribution from each distributed generator while voltage magnitude and frequency are regulated in the islanded mode of operation. The control and process variables consequently change contingent upon the mode of operation. Results have been presented on the ability of the controller to track varying power generation as well as dynamic load change. The proposed control algorithm has been simulated with linear loads and step changes in a Matlab/SIMULINK based microgrid model.