Heating of the induction motor rotor with damaged squirrel-cage

The work presented calculation results of a small power (1.5 kW) squirrel cage motor warm-up.Computation was realized with normal load. There is two models: one with non-damaged rotor and second one with three broken rotor bars. Calculation of coupling transient magneto-thermal field was realized with two-dimensional field-circuit motor model. There is a linear temperature characteristic of aluminum resistivity in squirrel cage, and a linear temperature characteristic of a thermal parameters in squirrel cage and core. Heating characteristic of motor with non-damaged rotor and another one with three broken rotor bars was compared. Heat distribution in rotor was investigated in both situation, in thermal transient state and after its.