Research on Robust Control Strategy for Hybrid Energy Storage of DC Micro-Grid System

Abstract

DC Micro-grid system is drastically dependent on energy storage system that will provide compatible power required between power output of new energy and the loads. This article addresses the new type of robust control strategy specifically designed for the hybrid energy storage system of batteries and super capacitor for the DC micro-grid. For the purpose of such robust control strategy, the batteries are used to supply the energy in a stabilized manner while the super capacitor is used to supply the energy with fast transients. This method is used for stabilized energy filtered by conventional low-pass filter using fuzzy rule based controllers are used for further energy filtration at the sharp end. Compared with conventional control strategy, it will further reduce the current stress for battery while improving battery life time. In addition, it is featured with simple control, less computations and easy-to-realize. Furthermore, such system also incorporates energy control algorithm that will retain the state of charge of both batteries and super capacitor within the limit, thereby preventing the hybrid energy storage system from overcharge or over discharge so that the life time of hybrid energy storage system can be guaranteed. In the end, the simulation test platform established in Matlab/Simulink for DC micro-grid system will be used to verify the effectiveness of the control strategy as put forth.