The conventional corona detection method cannot accurately locate discharge position and is sensitive to field interference.In this study

the corona discharge facula areas in UV images were extracted with digital image processing algorithm and used as a parameter to quantify the corona discharge intensity.In laboratory

the UV imaging characteristics of corona discharge in severely non-uniform electric field were studied with a rod-plane gap model

and the relationship between the facula area and the maximum discharge capacity or the cumulative discharge parameters in positive and negative half cycles was analyzed and discussed.The results show that for the discharge in negative half cycle

the maximum current pulse exhibits a nonlinear relationship with the facula area

but the cumulative discharge exhibits an approximately linear relationship with the facula area.For the discharge in positive half cycle

both two current pulse parameters exhibit approximately linear relationship with the facula area.So the corona facula area can be used to assess the discharge development stage and tendency

and to approximately quantify the peak value of current pulse and the discharge quantity.