Research On Corona Characteristics Of Generator Under The Conditions Of High Altitude

Generator insulation is the key of its reliable operation and long service life . Corona discharge is an important symbol of the generator insulation aging.As the air at high altitudes is thin, the generator corona voltage will be decreased obviously. It is helpful for ensuring the generators operating economically and securely and saving the engineering investment under the high-altitude conditions to research the cornea generator features under the same conditions. This paper has been made research mainly about the following corona characteristics of the high-altitude generators from both the theoretical and experimental aspects.Firstly, Starting from the gas discharge ,the article carried out a detailed analysis of the mechanism about generators corona and made sure its various hazards.Established models of the generator stator winding's slot and the end without anti-corona.Through the theoretical calculation ,achieved the disciplinarian of the electric field to the department of the generator's slot and the end.It got the conclusion that all kinds of HV-generators without anti-corona would generate corona discharge.Also the article offerred the ANSYS non-linear simulation of the generator stator winding's slot and the end,the result showed that the electric field of the corner and the end of generator stator winding is very irregular.The simulation experiments of low voltage got the same conclusion.Secondly,HV-generators which running on plain areas(altitude 1000m or less)with different anti-corona structures has been calculated,and according to the national standard GB311.1-1997, calculated the inception voltage of air discharge under the different altitudes.it found generators fully meet the requirements of anti-corona in the plain areas but can not meet the requirements of anti-corona under the conditions of high altitude. So the article proposed the special of HV- generators corona under high-altitude conditions, and designed two different anti-corona structures of HV-generators for the high altitude, and verificated and further studied from the test aspects. Lastly, through analysed the experimental data, it found that there are a big gap between the experimental value and theoretical value. the article accessed to the air discharge inception voltage correction factor of altitude by the calculations, the rusult has practical significance for the anti-corona of generators running under the conditions of high altitude of near or between the experimental places.