3-D Transient Model of Drawing Vacuum Arc Coupled With CuCr Alloy AMF Contact and Anode Thermal Process

In this article, a 3-D transient model is established to simulate the transient process of the drawing vacuum arc with CuCr alloy cup-shaped axial magnetic field (AMF) contact. At the same time, the parameters of the anode temperature and vacuum arc are calculated self-consistently in the model. Based on the 3-D transient model, the process of arc change to anode active mode under actual magnetic field is studied. The simulation results show that the arc experiences complex change processes at different stages under realistic physical conditions. In the initial stage, the arc has not occupied the entire contact. This makes the current density, electron temperature, ion temperature, and energy flux density very large. So the anode temperature increased rapidly in the initial stage under the action of the vacuum arc with a smaller diameter. Meanwhile, the AMF is small due to the eddy current in this stage. Then the arc expands throughout the contact as the current continues to rise. At the same time, the AMF generated by the cup-shaped contact makes the ions rotate. It can be observed that the ion rotation at the slot is more intense. Then the current starts to decrease. But the anode temperature did not immediately decrease. Its maximum value appears 1.5 ms after the peak current. And the electron temperature and ion temperature at the anode are still high due to the increase in gap distance and the anode change to active mode in this stage. At the same time, the high-temperature area of the anode is still expanding at this stage. Finally, the anode temperature and arc morphology were compared with the experimental results. The simulation results were in good agreement with experimental results.