For discovering the transmission rules of rotor fault features of ind uction motors in ACDCAC converts, the DCside current of converters and the ACside current of rectifiers are analytically analyzed using switching functi ons of converters and rectifiers when induction motors driven by ACDCAC conv erters develoｐ a rotor fault. The frequency components corresponding to rotor f a ult features are found. The experiments on an induction motor with one and two b roken bars are conducted, and their results are able to prove the correctness of the theoretic analysis. The work in the paper provides theoretic foundation for detecting rotor faults from the the ACside current of rectifiers in ACDCA C converters.