As frequency increases, induced emf and hence current and torque in the rotor coil increase, for a given input current to the stator coil. The point is that we can operate such motors at very high frequency like 10 kHz, at low input currents like 100 mA, thereby reducing the power consumption of the motor, but at the same output torque.
Then why is it not practically implemented, instead of typical low frequencies like 50,60 or 400 Hz ?
(If the problem is that at high frequencies, reactance increases, thereby producing low current to the stator,we can easily eliminate this by inserting a capacitor in series ,to resonate the circuit and eliminating reactive part totally. As frequency increases,capacitor size also reduces.)
Then why is it not practically implemented, instead of typical low frequencies like 50,60 or 400 Hz ?
(If the problem is that at high frequencies, reactance increases, thereby producing low current to the stator,we can easily eliminate this by inserting a capacitor in series ,to resonate the circuit and eliminating reactive part totally. As frequency increases,capacitor size also reduces.)