Esgee Technologies will present “Simulation of Arc Quenching in Hermetically Sealed Electric Vehicle Relays” at the SAE International World Congress Experience 2018, April 10-12, at the Cobo Center in Detroit, Michigan.
High-voltage relays perform a key role in determining safety and protections of Electric Vehicles(EV)/ hybrid automotive systems. The primary function of a high voltage relay is to mechanically separate electrodes under a short circuit situation, and isolate the motor drive electronics from impending damage due to high currents (~1000 A). As the relay breaks contact, significant arcing can occur due to high currents. Several methods can be applied to ensure immediate mitigation of arc within the relay, thereby reducing the electrical cutoff time. One such technique is to draw the arc towards the walls of a hermetically sealed chamber (using external magnets), and quenching it as it makes contact with the wall. Other techniques involve using an inert gas within the chamber to prevent arcing to occur in the first place.
This paper discusses the numerical modeling of arc formation and mitigation inside sealed electric vehicle relay. A high-fidelity, multi-dimensional, equilibrium arc solver-VizSpark is used to model the dynamics of arc formation and mitigation. Electrode motion is modeled using an immersed object method. The effect of several parameters such as pressure, gas composition and magnetic field strength on arc propagation speeds and cut-off time are studied.