On-line detection of corona discharge in stator winding of large generator plays an important role in ensuring safety of generator equipment and stable operation of power system. Aiming at the problems of calibration difficulty、inaccuracy and susceptibility to interference of existing visual and ultraviolet imaging methods, this paper proposes an ultra-high frequency detection method for corona discharge wireless detection of large motors based on electromagnetic wave and electromagnetic field theory. Based on the three parts of signal detection, front-end processing and signal calibration, this method designs and forms a complete high-frequency corona discharge wireless detection scheme, and carries out test on winding corona discharge. The research results show that the proposed method has the advantages of high frequency, wide bandwidth, high sensitivity and high signal-to-noise ratio. The designed scheme can effectively detect corona discharge signals under different typical defects of stator bars. The research results can provide reference for the on-line detection of corona discharge in stator windings of large motors in power plants.

UHF detection,Corona discharge,discharge calibration,High frequency antenna,Online detection