A Piecewise Analytical Transient Model for Hybrid Relays Switching Under Combined Resistive‐Inductive Loads

ABSTRACT This study presents a piecewise analytical transient behavioral model for hybrid relays, aiming to describe the multistage current evolution during switching under combined resistive–inductive loads. By introducing a time‐sliced modeling framework based on the dominant conduction mechanism in each stage, the transient process is decomposed into semiconductor conduction, arc‐dominated conduction, and metal oxide varistor (MOV) energy absorption phases. Compared with conventional piecewise models mainly developed for single‐mechanism semiconductor devices, the proposed approach extends the analytical transient modeling methodology to hybrid switching devices involving multiple coupled physical mechanisms. An experimentally derived dynamic current model of MOV is incorporated to improve the prediction of transient characteristics during the commutation process. The influence of key parameters, including arc voltage and stray inductance, on current commutation characteristics is quantitatively evaluated through sensitivity analysis. The proposed model is validated by experimental tests and simulation calculations on hybrid relays in typical low‐voltage DC systems, demonstrating good agreement between measured and calculated results, as well as the effectiveness of arc suppression during switching.