Diagnosis of electron temperature of arc plasma in vacuum circuit breakers

Abstract

Plasma parameters of vacuum arc, such as electron temperature, electron density and ionization etc. are very important to the development of vacuum circuit interrupters. However, few methods are taken on the plasma parameter diagnosis. Here, a new way to get arc plasma parameters in vacuum circuit interrupters is proposed. The feasibility of diagnosis of electron temperature of arc plasma parameters in vacuum interrupters according to CCD (Charge Coupled Device) digital image processing is analyzed. A set of experimental setup based on a demountable vacuum chamber is designed. An images collecting system using high-speed and high-resolution camera CCD is built. Vacuum arc can be ignited in the demountable chamber and the images can be captured by CCD. Combined with the principle of temperature measurement with colorimetric method, the distribution curve of electron temperature in vacuum arc can be got in the condition of low voltage and high current. From the results we can see that electron temperature in the arc center is higher than those in other places, and the highest temperature in the distribution of electron temperature is about 2.9eV, which agrees well with other's results diagnosed by probes or other method. The feasibility of CCD method is also validated by the experimental results.