Application of Induction Motors

Abstract

An electric motor drives its load in a steady-state condition when its electromagnetic torque is just equal and opposite to the torque exerted by the load. (This statement assumes that the torque corresponding to the rotational losses is either negligible or that it has been incorporated into the load torque.) In other words, the motor and its load are settling on that speed at which this condition of equilibrium is satisfied. With the aid of a given torque-speed characteristic (like that of Fig. 13-14), the steady-state speed is determined as that speed at which the magnitude of the motor torque equals that of the load torque.