The extreme scalar control system of mine shuttle car was analyzed when changing parameters in the operation of asynchronous squirrel-cage motor. The need to intensify the processes of self-propelled wagon requires a modernized control system, providing an increase in motor torque in starting and braking modes. Modernization lies the use of specialized laws of frequency control, calculated taking into account possible loads of the drive. As a criterion for the effectiveness of proposed laws an electromechanical criterion was selected which characterizes the ratio of torque to the stator current. The value of this criterion is subject to change due to variations in the parameters of the induction motor, especially active resistances. Study of this impact shows that even with significant variations in resistance value of the criterion of the system is higher than its value in conventional systems. The results of numerical simulations, confirming the main conclusions of the work, are given.