Voltage sag and unbalance pose a serious power quality issue for the electric power industry. The induction motor has widely used the machine in process industries (around 70%). In this paper, the performance of the Induction Motor Drive (IMD) under the condition of voltage sag and voltage unbalance is studied. The drive model is modelled in Matlab/Simulink environment and the simulation results are obtained for time-varying load. The performance of the IMD under different indexes viz. variation in current, speed and torque is investigated under varying sag depths and durations. The ripples in speed and torque are also investigated under unbalance conditions.