516 / 2017-05-11 11:45:44

Study on the Influence of Breaking Parameters and Load Characteristics on Arc Energy

dynamic arc,breaking velocity,breaking current,load characteristics,arc energy

The arc energy has an important influence on the performance, breaking capacity, life and reliability of the switch. The forming process of the arc between contacts in high current is divided into two stages: the metallic phase arc and gaseous phase arc. The breaking parameters such as current rate, breaking velocity determines diffusion velocity and metal vapor concentrations in arc-extinguishing medium, in addition, the load characteristics determines the arc-igniting time and arc energy. The influence of the breaking parameters and load characteristics on the steady arc energy is studied in this paper to solve the breaking problem of the switch at high current rate. Based on the theory of magnetohydrodynamics, a simplified two-dimensional dynamic arc model of switch is established and the variation law of arc temperature field, current density and arc shape of the contact, are analyzed under the conditions of different current rate, breaking velocity and physical properties in the process of arc generation. At the same time, the arc voltage, arc current, arc-igniting time and light intensity under the condition of resistive and inductive loads are measured and compared with the simulation results on experimental platform, to show the influence of different parameters on arc energy. Simulation and experimental results show that with the increasing of arc current arc current density and arc temperature increase, arc column shrink, and the arc energy increases. In a certain range increasing the contact breaking velocity is beneficial to shorten the arc-igniting time and reduction the arc energy. The research results can provide a reference and basis for the overall optimization design and breaking technology of the switch.