A Rule-based Energy Management Strategy with Current Estimation for Controlling Grid Connected Hybrid Energy Storage System

The design of an appropriate energy management strategy (EMS) is the most important challenge in the hybrid energy storage system (HESS). This paper presents a novel control strategy based on a combination of rule-based EMS (RB-EMS) and a current estimator for a battery/supercapacitor (SC) HESS in a DC microgrid that is connected to the AC grid. Versus the previous RB-EMS, the proposed strategy has no need to sense the power of loads and generation units, due to the use of the grid-required current estimator. In the proposed EMS, the amount of excess or deficit power that must be compensated by HESS is estimated by the use of a Kalman Filter. Furthermore, the proposed EMS ensures the effective power allocation between the battery/SC and AC grid, DC link voltage stabilization, controlling the Battery and SC State of charge (SoC), and improving the battery life span by responding to the SC to sudden power fluctuations. Eventually, the validity of the proposed EMS is investigated by simulation results that are carried out in MATLAB/SIMULINK.