The application of thyristor switching to induction motor speed control has resulted in a number of unconventional supply systems. One such technique, which has been successfully employed in a number of applications, is variable voltage control by means of symmetrically triggered thyristors in the stator phases of a wye-connected machine. In our project, an analytic method for predicting the steady-state performance of such a system is presented using the state variable technique. The use of symmetry of the solution permitted an additional reduction in the computation time. Since matrix techniques are utilized throughout the analysis, and the equations are implemented into a digital computer program. Hence, the method is well suited to the evaluation of proposed motor designs when used in conjunction with thyristor voltage control. The torque-speed characteristics of a typical drive system simulated using the MATLAB Simulink models are included and the results compared to an analytical solution formed. It is demonstrated that a computed solution will favorably predict the performance of an actual system.