THE MICA INSULATION OF  ROTARY ELECTRICAL MACHINES  WITH HIGH RESOURCES OF ELECTRICAL STRENGTH

Pak V.M.*, Drachev A.I.**, Gilman A.B.**, Starovoitenkov V.V.***, and Vakser N.M.***

*Elinar Holding Company, Russia, TICHO@elinar.ru

**Institute of Synthetic Polymeric Materials, Russian Academy of Sciences, Russia, plasma@ispm.ru

***St.Petersburg State Technical University, Russia

Some new composite insulating materials were developed on the base of mica-tapes contained the PET film. There were carried out the comparison resources tests of the long-time electrical strength of different kinds of mica insulation with PET-E film and without one. The tests were carried out with the coils of the motors  brand. The coil insulation was made  on the base of the Resin Rich tapes and the VPI tapes. The insulation tapes were available from the plant of electro-insulation materials Elinar Joint Stock Company. These  tapes were consisted  of the  impregnate or not impregnate layers of  glass fabric, mica–paper and PET film.  The experimental values of the random quantity of the break-down time of the insulation were processed by means of the three-parameter Weibull distribution. The Weibull distribution parameters were derived by the method of the moments [Hauschild W., Mosch W. Statistik Für Elektrotechniker. Eine Darstellung an Beispielen aus der Hochspannungstechnik. Berlin, VEB Verlag Technik, 1984]. The design-basis values of the snap-action break-down probability (immediately after the high voltage impressing) were established for the all insulation types of the rotary electrical machines. There were also established the time, in which the break-down probability  is  equal to zero,  and the break-down time with the 63% probability for the  insulation with PET film and without one. The results of the tests were shown that the use of  PET film in the mica insulation composition  increased the resource of the electrical strength  of the rotary  electrical machines  insulation  in several times.