Energy dielectronics-principles and methods for calculation of electric strength of insulation in HV transformers

Energy dielectronics is the scientific direction in physics of dielectrics where the ideas and methods of chemical thermodynamics and energy crystal chemistry are applied to analysis of processes in solid dielectrics and development of quantitative methods for determination of their properties. Previously (Yu.N. Vershinin), the method was proposed, permits the calculation of impulse breakdown voltage U/sub br/ of solid organic and inorganic dielectrics with accuracy suitable practice. This result was developed concerning criteria of assessment the electric strength of insulation in HV transformer under the strength of lightning impulse and AC. All this investigations have dealt with the typical component models (turn-to-turn, section-to-section). Breakdown in insulating oils can be described by Vershinin hypothesis if the liquid can be described as crystal in an electrical field. Under equal breakdown conditions, U/sub br/ is determined by a value of specify energy characteristics, A/sub c//sup o/ (for example, A/sub c//sup o/=153 kJ/cm/sup 3/) for transformer oils. The equation take into account: time of voltage application, length of discharge gap, breakdown probability, field form, conductor insulation. Experimental and theoretical results are in satisfactory agreement.