Imaging and spectrum diagnostics of air arc plasma characteristics

This paper is devoted to the study of the air arc plasma characteristics and consists of two parts. An optical high-speed imaging system is integrated with pressure sensing, arc current, and voltage measurement to investigate high-speed and high-temperature unsteady arc plasma motion in a molded case circuit breaker (MCCB) model, especially with the influence of polyoxymethylene (POM), polycarbonate (PBT), nylon, and ceramic arc chamber wall materials. It demonstrates that the performance can be improved effectively by adopting POM and nylon gassing materials. Also, spectrum diagnostics is introduced to analyze the influence of polymethylmethacrylate (PMMA) gassing material on the temperature of arc in a simple model. It shows that material added adjacent to cathode is more effective to cool the arc, compared with the case of anode.