Discussion on Active Television Interference Characteristic of UHV AC Transmission Line

High-voltage transmission line corona and sparking will bring television interference (TVI). Study has been seldom executed about active TVI from HV transmission line, and much less research on UHV AC lines. Based on present literatures, this paper brings forward test method of TVI from HV transmission line. Near straight span and tension tower of Chinese UHV AC Pilot Demonstration Project, several tests about TV picture, TVI field strength, the television signal field strength before and after lines energized, has been carried out in good weather. According to observation, interference characteristics to TV picture has been analyzed. Results indicate that, with increasing distance from the outer phase, UHV single circuit TVI field strength in fine weather attenuates negative exponentially. This paper illustrates it is questionable to use CISPR quasi-peak value for assessment of interference on TV picture caused by UHV transmission line corona and sparking noise.