A DC microgrid integrated dynamic voltage restorer with model predictive control

This paper presents a DC microgrid integrated dynamic voltage restorer (DVR) system to mitigate the grid voltage sag and swell. The DC source of the DVR is the DC microgrid, including the PV array and hybrid energy storage system consisting of lithium-ion battery and supercapacitor. Compared to the conventional DVR supplied by pure energy storages, the DC microgrid will prolong the operation the DVR because the renewable energy source can supply the DVR or charge the HESS occasionally. The DVR is regulated by a model predictive control (MPC) method to conduct the compensation of voltage sag and swell. The design of the MPC method for DVR and controller for the system are presented in detail in this paper. In order to validate the performance of the DC microgrid integrated DVR system and the corresponding control method, several simulation studies are conducted including the scenarios of voltage sag and voltage swell. The simulation results indicate that the proposed system works effectively and achieve compensation of the grid voltage sag and swell successfully.