Research on vibration behavior of the stator of large electric machine considering cooling system and rotor structure

In this paper, the natural vibration mode shapes and frequencies of the stator of large electric machine are computed by finite element method (FEM). In FEM model, several boundary treatments are especially considered, including welded connection between boards of stator, bolt connecting structure between end housing and frame board, shrink fitting between rotor axis and bearing. The influence of cooling system and rotor to the natural modes and frequencies of the stator is especially analyzed and discussed. By impact testing on the stator of a large electric machine, the main modal parameters including natural modes and frequencies of the stator are identified. It is verified that the FEM calculation of vibration modes and frequencies of the stator is valid by contrasting calculation result with experiment data.