507 / 2017-05-10 22:24:10

Study on Influencing Factors of Arc Characteristics of DC Contactor

arc voltage, arc shape, interruption process,DC,hydrogen arc

In order to solve the problem of poor reliability, short life and large volume of DC contactor in DC power supply system, in this paper, the MHD arc models of hydrogen, nitrogen and helium in the arc extinguish chamber which based on the bridge DC contactor were respectively established, and then the dynamic process of the arc was simulated when the contact is interrupting. By analyzing the spatial and temporal distribution of arc temperature , pressure, airflow field and the motion trajectory in the contact ,this study research the factors such as different magnetic field, pressure ,breaking speed which influence on the temperature, voltage, current and arcing time of the arc . To verify the correctness of the simulation, the arc voltage, current and arcing time were collected in the conditions of different magnetic fields, pressure and breaking speed of each media when the contact is interrupting, by using a transparent, sealed and detachable arc extinguish chamber in a DC test circuit. The high-speed camera is used to photograph the arc, by which the motion pattern and its characteristics of the DC arc was analyzed. The results show that in a certain conditions of breaking speed and pressure, using H2 as the arc - quenching medium and cooperating with the effective magnetic blowing can improve the arc - proof performance and the breaking capacity, which provides a reliable reference for the design of DC switchgear.