基于激光诱导等离子体的真空开关真空度检测稳定性研究

The vacuum degree detection method for vacuum switches based on laser-induced plasma imaging is a non-contact approach that holds promise for achieving safe and reliable online monitoring of vacuum degree in vacuum switches. However, the evolution of laser-induced plasma is a highly complex physical process, where factors such as laser energy and delay time of plasma measurement directly impact plasma imaging. The influence of these factors on the stability of plasma imaging needs to be further studied. In this study, the effects of laser energy, average times of plasma imaging, plasma measurement delay time on the stability of plasma imaging and integral of plasma radiation intensity are investigated. Experimental results demonstrate that the plasma imaging and plasma radiation intensity integral do not change significantly with the average times of plasma imaging, which can be used to characterize vacuum degree. Furthermore, the relative standard deviation of the plasma radiation intensity integral displays a monotonic decrease with increasing of average times and laser energy, while it increases with delay time. This suggests that enhancing the stability of plasma radiation intensity integral can be achieved by imaging the plasma multiple times and then averaging, increasing laser energy, while reducing the delay time for plasma imaging. These findings contribute to improving the accuracy of vacuum degree detection. This study provides guidance for parameter optimization in the vacuum degree detection method based on laser-induced plasma imaging for vacuum switches, and establishes an experimental foundation for its practical engineering application.