Simulation of Arc Quenching in Hermetically Sealed Electric Vehicle Relays 2018-01-0765
The goal of this work is to investigate arc quenching in electric vehicle relays using high-fidelity computational modeling. Rapid arc quenching is an essential quality of state-of-the-art high voltage mechanical relays in electric vehicles. As a relay begins to break electrical contact, strong arcing can occur which delays the process of isolating the circuit from a sudden current surge. The strength and duration of the arc has a significant impact on the safety of electric vehicles as well as on relay contactor erosion/lifetime. A thermal plasma modeling tool is used to estimate switch-off time in an arc relay using hydrogen and air as working gases. The response of arc dynamics and switch-off time to the gas composition and external magnetic field strength is studied. It was observed that a hermetically sealed chamber filled with hydrogen is significantly more efficient than air at quenching the arc. Further, a strong magnetic field was seen to sufficiently stretch the arc, and thereby quickly quench it.