Developments of power electronics semÏ-conductor switches has enabled the application of voltage source inverter induction mot or drives to railway traction. In order to ensure reliable and safe operations, a systematic study of drive fault modes is required. Particular attention is paid to the induction motor because it passes on the fault to the mechanical transmission, which is a vital element for safe operations. Hence, 3 phase short-circuits of a traction motor are studied by the finite element method. The results are noticeable : oversaturation of leakage flux path, CUITent displacement in the rotor cage, level of rotor bars stresses comparable with the centrifugaI force value. This study is achieved by the definition of an improved equivalent circuit usable for large transient operations modeling and the presentation of an extremely simplified analytical formulation of three phase short-circuits in order to make easier physical interpretations. At last, a systematic study of voltage source inverter faults is carried out on the base of a drive vector mode!. At each step of the study, experimental validation procedures are proposed. This study points out the relations between the motor electromagnetic state and the fault conditions
