Design and Implementation of an Embedded Control System for the Interconnection of a DC Microgrid to the AC Main Network

This paper presents the design of an embedded control system and its implementation on a DC-AC bidirectional converter for the interconnection of a DC Microgrid (MG) with the AC Main Network (MN). This control system was designed in LabVIEW and implemented on the NI myRIO platform, and it was used for the synchronization of the MG with the MN. Its main goal is to keep the stability of the DC bus when energy is supplied to or extracted from the MN. The MG is composed of two 500 W photovoltaic panel arrays (PAs), each with a Boost DC-DC converter to generate a DC bus of 190 V, and a DC-AC bidirectional converter that interconnects the MG with the MN. The control system was tested considering nonl-inear loads such as computers, commercial fluorescent lamps, and LED, with the aim to analyze the response of the system to real life conditions. Results show that the embedded control system is capable to stabilize the DC bus at a voltage level of 190 V ± 5% when interacting with the different non-linear loads connected to the MG. This is an improvement on the control of the voltage variation previously presented in the literature of 190 V ± 10%.