Real-Time Simulations for Testing of a Low-Voltage Microgrid with MMC-DSTATCOM

This paper presents a real-time simulation model of a low-voltage (LV) microgrid comprising renewable energy sources, a battery energy storage system (BESS) and a modular multilevel converter (MMC)-distribution static compensator (DSTATCOM) for reactive power compensation to support a distribution network and utility loads. The model is developed using MATLAB/Simulink® and the real-time test environment is composed of an OPAL-RT simulator. In offline and RT-Lab-based online simulations, the model is investigated for grid-feeding, grid-supporting, grid-following and grid-forming operations of the microgrid inverters. The MMC-DSTATCOM operation is tested for different reactive power control scenarios both in grid-following and grid-forming modes. In this study, one of the major challenges that affects real-time simulations is employing switching power electronic converter models and their controls with significantly low overruns in the RT-Lab platform. It is observed that microgrid and switching converter operations are successfully realized in real-time simulations with significantly low overruns for
$25\ \mu\mathrm{s}$
step-size.