Dynamic performance of induction motors in control systems

The paper analyses the behaviour of induction motors in control systems in response to sinusoidally varying torque distrurbances by using a 2-coil rotor model. It is found that induction motors exhibit resonance and possibilities of instability in response to torque disturbances, and transient torques substantially greater than the steady-state peak torque of the motor may be generated in the region of resonance. It is also observed that, in certain frequency ranges, the speed may be considered as leading the torque disturbances. Extension of previous frequency-response analysis in response to excitation-frequency variations and applicability of the present analysis to constant-net-flux operation are also given.