Research on Multi-Physics Coupled Modeling Method and Failure Characteristics of MOA

As the core component of 10 kV distribution network lightning protection systems, the reliability of metaloxide arresters (MOA) directly impacts power system safety. With the widespread application of MOAs, research on numerical modeling and condition assessment has progressively advanced. This study proposes a digital multi-physics-based methodology for analyzing MOA failure characteristics to address the limitations of existing numerical models in characterizing actual electrothermal behavior and clarifying failure mechanisms. Starting from the operational characteristics of varistors, we construct a multi-physics model of MOA and validate it through a Temporary Overvoltage (TOV) simulation framework. Based on simulation results, we investigate the failure mechanisms of metal-oxide varistor discs within MOAs. This research establishes a numerical model that accurately reflects MOA electrothermal behavior while elucidating failure mechanisms, providing theoretical support for condition assessment and lifespan prediction of MOAs.