Improved Performance of a Converter Operating as a Power Interface in Hybrid Microgrids Using Fractional Order PI Controller

The problem of maintaining a constant DC voltage in a slave microgrid connected by means of an interleaved three-phase converter to a master grid is of a well-known importance. Thus, starting from the detailed description of the topology and mathematical model of the converter operating as a power interface in hybrid microgrids, their transfer functions and the current and voltage controllers in this topology, this article shows that, by using a Fractional Order Proportional Integrator (FO-PI) controller the results obtained are superior as compared to the use of PI classic controllers. The tuning of the FO-PI controller is achieved by using the Fractional-order Modeling and Control (FOMCON) toolbox. The superiority of these controllers, both when there is a disturbance caused by the current flowing through the slave microgrid, and when there is no disturbance is demonstrated by numerical simulations performed in the Matlab/Simulink development environment.