Voltage Regulation of DC Microgrid by Robust Back-stepping Control Technique of Voltage Source Converter

Abstract

DC micro-grids are gaining wide acceptance in the smart grid paradigm. Integration of renewable and clean energy resources either in the transmission or distribution systems require effective control strategy for system operation and stability. This work presents a robust control strategy for a Voltage Source Converter (VSC) interfacing an integrated system comprising of Photo-Voltaic (PV) array and a battery unit with grid. Such a system is associated with intermittent output power and uncertain demand of the PV and load units, respectively. In order to make the control strategy robust to the power exchange through the point of common coupling (PCC), a new control design of VSC is proposed and theoretically validated. Detailed Lyapunov synthesis has been done to design a control strategy so that the system experiences stable DC link voltage despite of external disturbances. Extensive simulation studies have been carried out to ensure robust tracking performance and system stability against disturbance seen at the PCC.