modeling and a rotor field-oriented control (RFOC) system for controlling a faulty three-phase induction motor (three-phase IM when one of the phases is disconnected). In the adapted scheme for controlling the faulty IM, it is necessary for the PI controller coefficients to change. For this purpose, the gravitational search algorithm (GSA) is used for tuning of PI controllers. The results show the strength and ability of the technique to improve the performance of the faulty IM control.