ABSTRACT With the advancement of the electrification process, DC relays have been widely used in various fields, but the arc erosion problem of their contacts limits their service life and reliability. This paper establishes a three‐dimensional arc simulation model based on magnetohydrodynamic dynamics, and studies the simulation research on the arc erosion characteristics and surface roughness parameters of the contacts during the breaking process of DC relays. By constructing a three‐dimensional arc simulation model, simulation analyses were conducted for four working conditions: 450 V/100A, 750 V/100A, 450 V/300A, and 750 V/300A. The results show that the simulation results of the erosion area ratio, peak height and peak‐valley are highly correlated with the experimental results (Pearson correlation coefficients are 0.9479, 0.9950, and 0.9817 respectively). In addition, erosion skewness has been introduced to evaluate arc stability, allowing for a more intuitive observation of the erosion condition on the contact surface through simulation models. The sputtering mass and evaporation mass were calculated through a three‐dimensional arc simulation model, and the reliability of the simulation model was further verified by the erosion quality of the contacts. This provides important theoretical support for optimizing the erosion resistance of contact materials and extending the service life of DC relays.
Wang et al. (2026) studied this question.