Breaking Arc Model of Intelligent AC Contactor and Arc Extinguishing Analysis of Metal Plates

The breaking arc of intelligent AC contactor has an important effect on the performance and electrical life of contactor. In this paper, based on the magneto hydrodynamic theory (MHD) and the dynamic layering mesh technology, the mathematical model of air arc in the breaking process of intelligent AC contactor is established and the arc motion in arc extinguishing chamber and the metal plates cutting arc process are simulated and the validity of simulation model is verified by experiment. On this basis, the arcing characteristics of the zero-front-breaking arc under AC4 condition is studied. The arc extinguishing performance, arc motion, arc root transfer and the arc extinguishing chamber flow field of four different metal plates and magnetic field matching schemes are investigated. The research shows that the plates have a blocking effect on arc motion, and the greater the thickness of plates, the more difficult the arc cutting is. Dense plates arrangement has great hindrance to arc flow. For the zero-front-breaking arc, the arc extinguishing ability is hard to be improved by increasing the plate number. For the zero-front-breaking arc, the arc extinguishing performance can be effectively improved by appropriately reducing the thickness of the plates and applying external magnetic field.