-In this paper transient model of three phase induction motor using d-q axis theory in stationary reference frame, is proposed to estimate the transient behaviour of the motor. Simulation results as obtained on a test machine are compared with the experimental results and the Closeness between the two shows the accuracy of the model as proposed. Further model is used to investigate the transient behaviour of three phase induction motor, with two phase supply system, without and after including the effects of phase angle control. The effect of Source Impedance on induction machine under unbalanced and balanced supply with the variations in the %DOU(Degree of unbalance) are analysed with THDs on all phases.