Computer simulation of electric motor operation is particularly useful for gaining an insight into their dynamic behaviour and electro-mechanical interaction. A suitable model enables motor faults to be simulated and the change in corresponding parameters to be predicted without physical experimentation. This paper presents both a theoretical and experimental analysis of asymmetric stator and rotor faults in induction machines. A three-phase induction motor was simulated and operated under normal healthy operation, with one broken rotor bar and with voltage imbalances between phases of supply. The results illustrate good agreement between both simulated and experimental results.