Three-Dimensional Physics-Based Circuit Modeling of Battery Incipient Faults in Microgrid Applications

Battery condition directly affects the reliability, resilience, and safety of microgrids, making physically interpretable battery information an important input to situation awareness. In practical microgrid operation, battery monitoring commonly relies on terminal signals available to the supervisory energy-management layer. These signals do not directly reveal early internal degradation. This paper develops a three-dimensional physics-based circuit modeling framework for battery incipient fault information generation in microgrid situation awareness. A high-fidelity electrochemical model was employed offline as a virtual battery to generate controllable reference data that are difficult to obtain comprehensively through physical experiments. This virtual reference serves as the benchmark for validating the proposed circuit model. The three-dimensional physics-based circuit model then acts as the real-time modeling core, representing distributed electrochemical and thermal behavior at substantially lower computational cost. Across the evaluated discharge cases, the circuit model voltage outputs show that mean relative errors remain below 1.3% with respect to the virtual battery reference while achieving a tenfold reduction in mean solver time per step. The proposed model therefore provides an online-oriented foundation for extending battery-related situation awareness in microgrids from terminal-signal monitoring toward the model-informed representation of internal degradation.