Study on Secondary Release Mechanism of DC Relay Based on Circuit-Magnetic Field-Mechanical Coupling Calculation

DC relays are widely used in aerospace control, rail transportation, and other fields, with the reliability of their operation being a key factor in ensuring system safety. This article tests various models of dc relays and identifies a common phenomenon of secondary release, which can prolong the release time of the relay, increase contact arcing time, and shorten the relay's lifespan. To investigate the generation mechanism and effects of this phenomenon, a specific model of dc relay is chosen as the research subject. Experimental and numerical simulation methods are employed to establish a circuit-magnetic field-mechanical coupling model of the dc relay, and its accuracy is validated through experimental comparison. Based on the simulation results, the secondary release mechanism is analyzed from the perspective of suction and reaction force matching and contact motion characteristics. The study proposes mitigating the secondary release phenomenon by increasing the air gap in the magnetic circuit, which improves the suction and reaction force characteristics during the release process. This method decreases the release time while increasing the suction time, with the impact on release time being more significant. The findings lay the groundwork for optimizing the design and extending the lifespan of electromagnetic relays.