Incidentally a 3ph motor that was used extensively for crane hoists, but rarely seen today because of VFD etc, is the wound rotor AC induction motor.
Instead of shorting bars, the motor used rotor coils brought out via slip rings, the resultant 3ph was then rectified and a variable resistor bank placed across the DC, varying the induced rotor current.
When decreased to 0 Ohms, the speed was at maximum..
M.
Instead of shorting bars, the motor used rotor coils brought out via slip rings, the resultant 3ph was then rectified and a variable resistor bank placed across the DC, varying the induced rotor current.
When decreased to 0 Ohms, the speed was at maximum..
M.