Laser imaging technology for analysis of electric arc behavior in low voltage circuit breakers

Inhalt:
Electric arc behavior in a short circuit can be observed and recorded utilizing a Laser Arc Imaging System (LAIS) comprised of a laser light source and a high speed video camera. Both the arc chute and contacts are exposed and illuminated by the laser beam, providing a backdrop to showcase the electric arc emitted during a short circuit. The arc motion is recorded by a high speed video camera through a band-pass interference filter. This technique was thoroughly tested on several molded case circuit breaker (MCCB) samples. Frame by frame observations of the recorded footage provide crucial information regarding arc behavior over time such as shape shifting patterns, flow direction, and commutation with the arc plates and the electric contacts. As an example, the additional angular velocity of the movable contact arm is calculated by the quantitative data collected from the images. The arc roots displacements, velocity, and other properties could be similarly processed as well.