Optimal PV Power Smoothing in Hydrogen-Battery Systems Using an Adaptive Equivalent Consumption Minimization Strategy

Photovoltaic (PV) power plant variability presents a significant obstacle to grid stability. Hybrid energy storage systems (HESSs), which integrate battery energy storage systems (BESSs) with hydrogen units (i.e., electrolyzers and fuel cells), offer a viable solution to mitigate PV fluctuations and minimize power curtailment. However, existing control strategies are typically rule-based or offline-optimized, lacking the capability to address critical real-time challenges such as nonlinear efficiency characteristics, response delays in hydrogen subsystems, excessive hydrogen consumption, and battery degradation while complying with grid codes. This paper introduces an adaptive Equivalent Consumption Minimization Strategy (ECMS) for real-time, optimal power sharing among hydrogen-BESS systems. The controller minimizes a composite cost function that integrates efficiency-aware dispatch using empirical efficiency curves, health-aware penalties for aggressive state-of-charge (SOC) reversals and hydrogen overuse, delay-resilient compensation for hydrogen subsystem response lags, and degradation-aware control via online BESS aging assessment. Simulation results demonstrate that the proposed strategy significantly improves ramp rate (RR) compliance and system longevity. Compared to benchmark techniques, the ECMS reduces BESS degradation by 50% and nearly eliminates RR violations while maintaining hydrogen demand satisfaction and ensuring smooth SOC recovery.