Light spectra on AC corona [insulation condition monitoring]

In order to detect and monitor power apparatus insulation by means of measuring light spectra radiated from partial discharges, the characteristics of light spectra radiated from corona should be found out first. Previously, we have measured light spectra radiated from DC corona. The light spectra from AC corona are presented in this paper. The measured spectra range from 250 nm to 800 nm, and show some similarities to those from DC corona. The results of this experiment show that it is possible to detect and monitor insulation condition by measuring the light spectra radiated from partial discharge in air.