Optimized generalized super twisting observer based active disturbance rejection control method for PV/Battery energy storage system within DC microgrids under uncertainty and disturbances

The integration of photovoltaic (PV) system with battery energy storage system (BESS) in standalone DC microgrids provides significant advantages including direct DC coupling, reduced conversion stages and power losses, and enhanced power quality and system efficiency. However, complex dynamic interactions among DC-bus voltage, BESS current, and PV characteristics create substantial control challenges under system uncertainties and disturbances such as parameter variations, irradiance fluctuations, and load changes. To address these challenges, this paper proposes a novel optimized active disturbance rejection control (ADRC) strategy for simultaneous regulation of the DC microgrid voltage and BESS current. The key innovation consists in replacing the traditional extended state observer-based ADRC with an optimized generalized super-twisting extended state observer (OGSTESO), which delivers faster convergence, superior disturbance estimation accuracy, and enhanced robustness. This substitution significantly improves both transient and steady-state performance while mitigating the drawbacks of traditional observers-based ADRC. Additionally, the rime-ice called the RIME optimization algorithm was adopted in this paper to tune and optimize the GSTESO-based ADRC parameters to achieve optimal performance and adaptability under different operating conditions. The new optimized GSTESO-based ADRC enhances the control loops in terms of dynamic and steady state performance, tracking accuracy, robustness against system uncertainties and external disturbance, and noise mitigation. Finite-time stability and convergence of the GSTESO are verified via quadratic Lyapunov function analysis. Finally, simulation and hardware-in-the-loop (HIL) validation demonstrate the proposed OGSTESO-ADRC scheme’s superior performance, robustness, and effectiveness compared to traditional ADRC methods in guarantying stable PV/BESS-based DC microgrid operation under diverse uncertainties and disturbances.