491 / 2017-05-10 17:09:38

Research on the dynamic behavior of the arc between contacts of DC contactor

arc breaking,magnetohydrodynamics,arc root transfer,breaking condition, numerical simulation

Arc state at the moment when arc root transfer to arc runners affects the stagnation time of arc in the inlet area of arc quenching chamber, which plays a very important role in the movement and extinction of arc. Therefore, the studies of the dynamic behavior of arc lengthening and arc root transfer are of great significance to optimize the design of DC contactor. Based on magnetohydrodynamics theory, the air arc model is set up for the contact and arc runner at chamber inlet of a certain type of DC contactor and the dynamic behavior of the arc is simulated. The variation laws of arc length and arc root transfer under different capacity, breaking velocity and applied magnetic field are studied quantitatively. The relationships between the change of breaking condition and position of arc root, transfer time of arc root, the arc voltage and current when the arc root is completely transferred to arc runners are revealed. The influence mechanism of different breaking conditions on the dynamic behavior of arc is investigated. The applicability of different breaking conditions for DC contactor with different breaking levels is also summarized in this paper. Arc dynamic process taken by high speed camera and arc voltage and current curves measured experimentally are consistent with the simulation results under the same conditions. It proves that the research has certain guiding significance for the optimization design of DC contactor.