Analysis And Calculation Of Stator End Region Magnetic Field In Powerformer

In this paper Powerformer, a new kind of high-voltage generator, is introduced, which can be connected to electric network directly without step-up transformer. Multilayer concentric structure is adopted in its stator and the conductors in stator slots are high-voltage cables. New design overcomes the 36kV output limits of generators; the design concept and application prospect of this kind of generator are represented; finally according to its structure characteristic end region model is established and end region leakage reactance as well as electromagnetic force are calculated with the help of Finite Element Analysis software.Surrounding a model machine, the theory of three- dimension eddy current field and the method of calculating parameters according to energy are introduced first; after that end region model is established. Because the stator winding of Powerformer is multilayer concentric, its end winding is rather complex. It is difficult to establish and mesh the model. In order to simplify the procedure of computation, the mathematical model is simplified. And the principle is represented. On above basis the whole process of computation with ANSYS is represented, including meshing, loading current and boundary condition treatment. Finally vector distribution map ,end region leakage reactance and distribution of force on end region winding are achieved.In addition simplified model is introduced. In order to test the feasibility of this method several cases are calculated. The result proves that the method we took is feasible and reliable.The work of calculating end region magnetic field, electromagnetic force and end region leakage reactance provides a solid basis for completed analysis to the end region magnetic force and vibration in other conditions of Powerformer.