Characteristics of electromagnetic wave radiated from corona discharge

EMI radiated from corona discharge is a serious problem in both EMC and insulation condition monitoring of electric power apparatus. In order to take effective measures to decrease the EMI from corona discharge, the characteristics of electromagnetic (EM) wave radiated from corona discharge should be investigated. The reasons why this problem is complicated are mentioned. A physical model on corona discharge for needle-plate electrode in a closed loop has been presented; polarization pattern and orientation pattern of its EM wave have been analyzed. To verify the correctness of the physical model, a series of experiments have been carried out. Both experiment results and its analysis are reported in this paper.