Simulation and Experimental Analysis of DC Arc Characteristics in Metal Splitter Plate

Gas medium (N
₂
, H
₂
or N
₂
-H
₂
mixtures) and magnetic field are usually applied to extinguish the arc in high-voltage direct current (HVDC) relays. The presence of hydrogen will increase the probability of arc restriking, and when the arc extinguishing chamber is poorly sealed, it may also cause an explosion. The nitrogen reduces the probability of arc restriking, but the arc extinguishing time is similar to air. Therefore, in order to enhance the ability of arc extinguishing, avoid the arc restriking and increase the lifetime of the HVDC relay, the characteristics of the arc in the metal splitter plate and that of the arc root motion in the magnetic field are simulated by means of magnetohydrodynamics (MHD). The voltage and images of the arc are obtained by DC Arc Test System. The results show that increasing the external magnetic field is beneficial to the motion of the arc and shortens the time of arc movement on the contact surface. At the same time, the addition of the metal splitter plate on both sides of the contact is beneficial to increase the arc voltage and accelerate the arc extinguishing.