This paper presents a model predictive control (MPC) approach for energy management of a hybrid energy storage system (HESS), in an electric vehicle (EV). HESS constitutes the battery and the supercapacitor (SC) where the latter is used as an auxiliary source to reduce stress on the battery. Hence, an appropriate control strategy should be formulated for allocating low-frequency power fluctuations to the battery and high-frequency power fluctuations to SC. The conventional PI-based control strategy has a difficult tuning process, and its performance is affected when the operating point fluctuates. Therefore, an MPC-based control strategy is proposed because of its simplicity, intuitiveness, ease of implementation, and inclusion of nonlinearities and constraints.

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A novel control strategy for a hybrid energy storage system (HESS) is outlined and examined in this paper. In the proposed system, the battery is utilized to stabilize the moderate changing of power surges, whereas supercapacitor is utilized to stabilize the rapidly changing of power surges. A two-loop proportional-integral controller is designed for the closedloop operation of HESS. The source power and load power is not balanced because of the fluctuating conditions of photovoltaic (PV) power generation and load demand. This power imbalance causes fluctuations in direct current (DC) grid voltage. The DC bus voltage variations are mitigated using HESS, which is connected to DC grid through bi-directional DC-DC converter to enables the bidirectional power flow between energy storage devices and the DC bus. To enhance the life span and to reduce the current stress on the battery, the proposed method is employed with charge/discharge rate control feature. The proposed control procedure is realized in MATLAB/Simulink and the results are presented for different case studies. Experimental results are obtained for a two-input bi-directional converter at the sudden change in PV generation and load demand with the proposed controller. The proposed control strategy is effective for maintaining constant DC microgrid voltage under source and load fluctuations.

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This paper presents an advanced controller for multi-input bidirectional DC-DC power converter (MIPC) for hybrid energy storage system (HESS).When batteries are used for energy storage, their rates of charge and discharge are low, and this sets up current stress on the battery, decreasing its life. Supercapacitors (SC), with their higher power density, can react immediately to sudden fluctuations and can take care of this issue. However, SC alone cannot be used for storage, as they cannot supply power for longer durations. In HESS, batteries and supercapacitors are used together, as their contrasting characteristic makes them a perfect combination for energy storage. The HESS is interfaced with DC microgrid using MIPC. MIPC provides decoupled control of battery and SC power and also facilitates energy exchange between storage devices within the system. A controller is designed for DC microgrid application, with its operation modified to control both HESS charging and discharging operation, making it a unified controller. Conventional control schemes neglect uncompensated power from the battery system, and power sharing depends entirely on a low-pass filter (LPF). In the control scheme proposed in this paper, uncompensated power from the battery system is utilized to improve the SC system. This approach reduces the current stresses, increases the life cycle of the battery, improves the overall system performance to the step change in PV generation and load demand, and provides faster DC grid voltage regulation. Simulation and experimental results are developed for the proposed controller by varying photovoltaic (PV) generation and load demand, providing faster DC link voltage regulation.