This paper assesses the steady-state performance of cascaded IMs (induction motors) operating under voltage unbalance. Small sizes induction motors are connected in cascade instead of one big size induction motor to improve the electromagnetic system and to make the energy conversion process more efficient during both balanced and unbalanced operation. The two mechanically coupled induction motors could have the same ratings or different ratings. The paper analyzes the coupled machines system using the method of symmetrical components and MATLAB/Simulink software. The definition of the voltage unbalance using CVUF (complex voltage unbalance factor) is used. Coupling of induction motors with DC (direct current) motors is examined to investigate the effect of cascading on the electromagnetic torque of the entire set. A comparison of the effect of the unbalanced voltage on single and cascaded machines is illustrated. The purpose of such comparison is to determine which one has the best performance during the balanced and unbalanced operations. Furthermore, this paper assesses the impact of connecting induction motors in cascade on the energy conversion process. (C) 2013 Elsevier Ltd. All rights reserved.