ABSTRACT: An unbalance in a three-phase system can be seen as the presence of a negative sequence. In induction machines (IM’s), even a small negative voltage will cause a large amount of negative sequence current. The negative sequence will cause a synchronous frequency second harmonic pulsation and unbalanced currents in the system. In induction machine,unbalanced 3-phase stator voltages cause a number of problems such as over heating, over current and thrust on the mechanical component from torque pulsation. Therefore, the machine torque, flux, and reactive power will have a 100 Hz pulsation. Unbalance condition appear that using active crowbar protection and direct torque control. The control strategy is validated by means of simulation. Induction Generator (IG) connected in the power system under balanced and unbalanced load, symmetrical and unsymmetrical components of voltages and currents are described. The definition of unbalance factor, harmonic content and synchronous frame unbalance theory are also analyzed. Experimental results under balanced condition are presented.Keywords: Balance and unbalance IM’s, negative and positive and neutral sequence.