Experimental Investigations on Applicable Criterion for AC Corona Discharge Evolvement of Rod-plane Gap Based on UV Digital Image Processing

A measuring and analytical platform of corona discharge combining CoroCAM IV+ with the virtual instrument programming environment - Labview 8.0 - was designed. Selecting the proper algorithm and flowchart of the digital image processing, the Area Percentage of the UV image within the discharge zone was defined as the characterizing parameter of quantifying the intensity of corona discharge with processing the UV video of corona discharge recorded real time. Under the approximate standard atmospheric ambient, the study on corona discharge under the power frequency voltage of the rod-plane gap based on the UV digital image processing is carried out. The results illuminate that the flowchart of the digital image processing mentioned in the paper could reproduce the images observed by the UV imaging camera so as to ensure the validity of the quantifying parameter of corona discharge; the characterizing parameter could reflect the corona discharge development stages definitely; the regularity of the UV imaging of corona discharge attenuating with the observation distance is obtained; Standard Conversion Method - the applicable criterion of the corona discharge UV imaging detection is proposed.