Dynamic Resilience Evaluation of DC MGs: Integrating Real-Time Metrics With Lyapunov-Based Stability Assessment

This article introduces a set of new quantitative real-time resilience metrics based on bus voltage dynamics, with the aim of enhancing the operational resilience of dc microgrids (MGs) through real-time tracking of these metrics. Unlike traditional offline resilience assessment tools, our approach is measurement-based, enabling real-time resilience evaluation during various event phases, including degradation and restoration. We explore the dynamic interaction between system stability and resilience by analyzing how Lyapunov stability is related to the proposed resilience indices. This involves understanding how the system’s equivalent capacitance ( $C_{\mathrm { eq}}$ ), acting as virtual inertia, influences both stability and resilience, balancing quick system recovery with minimal degradation. Our findings reveal that stability metrics such as complex eigenvalues, the load-power-to-output-voltage transfer function (TF), and the Lyapunov function are intricately connected to our resilience metrics, offering a comprehensive view of system performance. Furthermore, we observe that a higher value of $C_{\mathrm { eq}}$ decreases system degradation but increases recovery time, underscoring the trade-offs involved in optimizing system performance. Extensive simulation studies, validated by real-time verification, substantiate the effectiveness of our metrics and highlight the critical role of virtual inertia in achieving resilient and stable MG designs, crucial for robust electrical infrastructures.