Calculation of the Switch Arc in Low Voltage Circuit Breaker Considering the Interaction Between the Contact Movement and the Arc Force

Abstract

During the interruption, the separation of the contacts plays an important role in different kinds of switch gears since the arc motion or the arc elongation will be affected. The movement of the contact could increase the arc length and then decide the arc behavior. In reverse, the arc current will be changed during the interruption and the Lorentz force will then influence the movement of the contact. It is necessary to consider this phenomenon to make the arc simulation more accurate and universal. In this work, low voltage arc plasma simulation in 3D with contact opening process has been established. Both the sheath and nonlinear magnetic material were taken into consideration. Calculation was based on magneto-hydrodynamic arc model, and a method of coupling different software to separately calculate fluid and electromagnetic field has been developed to fulfill the requirements above. Furthermore, a low voltage circuit breaker has been tested to validate the simulation with U-I characteristics.