Large-Signal Stability Analysis of Multi-Stack Fuel Cell Hybrid Power Systems with Virtual Inertia-Based Control

Multi-stack fuel cell (FC) hybrid power systems (MSFCHPSs) are high-order nonlinear systems with inherently complex nonlinear characteristics due to their integration of multiple FC stacks, power electronic converters, and nonlinear loads. Thus, MSFCHPSs are very vulnerable to destabilization by transient disturbances, which exceeds the capabilities of traditional small signal stability analysis. To explore the destabilization mechanism of MSFCHPSs, this article proposes a comprehensive large-signal stability (LSS) analysis framework integrating a full-order nonlinear model, including all main circuits, complete control loops, and FC aging effects, with virtual inertia-based control. The nonlinear system is transformed into a Takagi–Sugeno (T-S) fuzzy representation, enabling domain of attraction (DOA) estimation via Lyapunov theory and linear matrix inequalities (LMIs) with low computational burden and reduced conservatism. The method quantitatively assesses the influence of power distribution, virtual inertia parameters, circuit elements, control gains, and FC aging on LSS, identifying dominant stability factors. A hardware-in-the-loop (HIL) platform is developed to experimentally validate the proposed approach. Results show strong agreement between estimated and actual stability boundaries, confirming the method’s accuracy and practical applicability for MSFCHPS design and operation.