Study On Transposition Method For Stator Winding Of Multi Turn Of Large Induction Motor And Parameterized Modeling

Stator winding is an important component of large induction motor,and its transposition design is one of the key problems of large induction motor.With the increase of the capacity of a large induction motor and the increase of the number of the root of the stator winding,it is very important to design a new type of stator winding transposition.In this paper,a 5MW nuclear main pump drive motor is as an example,a 3D model containing the end of a given stock line is built and the calculation methods of strands current and circulating current losses are given,and the experiment verifies the validity of the method,strands current and circulating current losses of the stator windings of different transpositions are calculated,a new way of conversion combined void transposition method is put forward.According to the principle of constant cross sectional area of the strands,the 3D model of the involute form of the strands at the end of the windings is built by the combination method of sweeping method and curve fitting approximation method.The transposition structure of the winding with 360° transposition,extended transposition,less than 360° transposition and void transposition is given.The 3D mathematical model for calculating the leakage magnetic field of stator transposition bar is presented.Aiming at the network topology of different transposition type in stator winding,the calculation formula of circulating current losses is deduced,the validity of the presented method has been proven by comparing with the experiment data.The strands current and circulating current losses of the winding are achieved when the winding used 360° transposition,extended transposition,less than 360° transposition and void transposition,and the results are compared and analyzed.According to the analysis of the circulating current losses under different transpositions,a new way of conversion combined void transposition method is proposed,which verifies the effectiveness of reducing the circulating current losses of large induction motor stator winding of multi turn.Finally,in order to establish more complex and three-dimensional solid models of stator winding of multi turn,a 3D solid model automatic modeling program for large induction motor stator windings is developed.