Test facility of multi-factors aging for stator bars insulation of generator and design of specimens

In the present work, a new test facility of combined triple stresses aging for stator bars insulation of a generator was introduced. The facility can efficiently stimulate the three stresses, which are imposed on stator bar insulation of a generator in operation, and conduct a single factor, combined double factors and/or triple factors aging test at random. In order to satisfy the different requirements put forward to specimens in different measurement and consider the fact that mechanical stresses are applied differently at the local bar, test bars are divided into several specimen pieces and treated in different ways. The results of PD detection performed on different specimens subjected to electrical, combined electro-thermal or combined three factors aging, respectively, have given sufficient information on the synergistic effect of electrical and thermal, mechanical stresses on stator bar insulation with mica/epoxy aging. It is proved that the aging facility and specimens adopted are more perfect.