Published Paper Details:

Due to the widespread integration of renewable energy sources in DC microgrids, these microgrids are highly vulnerable to fluctuations in power generation, particularly concerning voltage stability. To mitigate these fluctuations, a Hybrid Energy Storage System (HESS) comprising both a battery and a supercapacitor (SC) is employed. The distinct characteristics of batteries and supercapacitors make them an ideal combination for applications in HESS. The HESS is connected to the DC microgrid through a double-input bidirectional converter, offering decoupled control of battery and supercapacitor power, along with facilitating energy exchange between the storage components. This paper introduces a modeling approach for the double-input bidirectional converter and designs a controller for voltage regulation in a DC microgrid. The modified operation of the converter enables the use of the same controller for both HESS charging and discharging operations, creating a unified controller. The designed controller proves effective in rejecting disturbances from both the source and load sides while ensuring the voltage stability of the DC microgrid. The proposed modified operation of the bidirectional converter maintains the State of Charge (SOC) of the low Equivalent Series Resistance (ESR) supercapacitor within the desired range. Simulation results validate the operation of the modified converter and the performance of the designed controller in maintaining voltage stability.