State-space modelling techniques although are now very often used in the analysis of power Systems, the application to the cage of thyristor-controlled induction motors is very now (Novotny and Fath l968, Uango and Ramamoorty 1972a and b), The powerful tool of state-space modelling techniques is applied to the steady-state analysis of voltage-controlled induction motors, by thyristor switching, in this paper. The method is a general method applicable to both single-phase and three-phase motors. Equations are derived with particular reference to two types of single-phase induction motors. Numerical examples are given and performance curves are plotted for each type of motor