FCS-MPC-Based DC Microgrid-Fed Shunt-Connected Multi-functional Converter Under Dynamic Operation Scenarios

The aim of this study is to investigate the power management algorithm (PMA)-based finite control set-model predictive controller (FCS-MPC) for effective and flexible operation of the DC microgrid-fed shunt-connected multi-functional converter (SCMFC). The DC microgrid encapsulates a solar photovoltaic (SPV) system, hybrid energy storage (HES), and localized DC-loads. A simple rule-based PMA is developed to estimate the reference currents for associated converters in the system under grid-connection and grid-islanded mode operation. On the other hand, the FCS-MPC is formulated based on the optimal switching vectors (OSVs) of corresponding converters in the system for current tracking control. Furthermore, with the PMA-based OSV-MPC strategy, the performance indices such as maximum peak overshoot, settling time, and steady-state error of the DC-bus voltage have been improved as compared to the conventional control techniques. Besides that, the THD of utility source current is maintained at < 5%, recommended by the IEEE-519 standards. The efficacy and performance of the system under study are verified and validated through MATLAB/Simulink and real-time simulation results using the OPAL-RT OP4510 real-time simulator under various dynamic operating conditions. The variations in SPV generation and DC-load on the DC-side, availability of grid, electricity pricing, and abrupt variation in linear (balanced and unbalanced), and nonlinear loads on the AC-side are considered for the result analysis.