Controle preditivo baseado em modelo para conversores formadores de rede com operação ilhada

Abstract

A Microgrid is composed by distributed generation, storage systems and local loads. However, its control and operation are complex, especially in islanded mode. In this condition, grid forming converters are responsible for maintaining microgrid proper operation by controlling voltage amplitude and frequency according to the reference. Currently, the use of predictive control has been growing, especially in power electronics converters. There are several types of predictive control, in particular, the finite control set model predictive control. It preditcts the future behavior of the control variables and, with this information, selects the best switching state according to the cost function optimization. This work consists of developing a grid forming converter, which operates in islanded mode and uses the finite control set model predictive control. A validation of this system is performed from simulations using the MATLAB/Simulink and prototype testing. The grid forming converter is tested with linear and nonlinear loads and with voltage and load variations. The results show the dynamic response of the algorithm is very fast, of about 1,17ms for voltage variations, for example. It is also noted the control is capable of harmonic rejection and it is robust to model parameter mismatches. In addition, the voltage is always regulated regardless of the type and magnitude of loads.