Study of power management of standalone DC microgrids with battery supercapacitor hybrid energy storage system

<p>In the last years, renewable energy (RE) is increasing widely in the energy sector, and microgrid technology is overgrowing. In this paper, stand-alone microgrid using solar photovoltaic (PV) energy as a source of renewable energy is simulated to provide power for direct current (DC) loads with hybrid energy storage system (HESS) which consists of battery and supercapacitor bank. The proposed microgrid system is tested under various cases of load and variable irradiance to confirm and validate the proposed management strategy to remain the DC bus voltage within a stable limit. The performance of DC microgrid is comparing with and without supercapacitor (SC) bank and notes a desirable decrease in the magnitude of transient voltage when using HESS. The sun power SPR-E19-320 standard was simulated to analyze system performance taking into account the constant load demand. Note that HESS helps reduce transient of DC voltage very effectively in all situations. Very large transients arise due to sudden changes in load demand is also compensated by HESS. The results obtained indicate that the stand-alone DC microgrid with HESS is very beneficial for reducing transient of DC-link voltage that occurs due to sudden change in load or fault. The proposed system is performed by MATLAB/Simulink environment.</p>

Dynamic performance improvement of wind-diesel power system through robust sliding mode control of hybrid energy storage system

Off-grid users can be provided with electricity via a hybrid integration of wind power generators and a diesel system functioning as a backup supply. However, due to wind power fluctuations and rapid load changes, system voltage and frequency variances may exceed permitted limits, resulting in aberrant system behavior. Therefore, to improve the dynamic performance of the wind-diesel power system, a hybrid energy storage system (HESS) made of battery and superconducting magnetic energy storage is installed with the system via a converter interface. Based on the switching manifold design, a sliding mode controller with the super-twisting feature is developed over the hybrid energy storage system (HESS) to carry out the required amount of power exchanges with the system accomplished through the control of converter operation. Lyapunov stability analysis is conducted to guarantee the asymptotic stability of the system. MATLAB simulations are performed to validate the improved performance of the system with the proposed scheme.