A winding connection does not give you constant power, constant torque, or variable torque. Manipulation of the input frequency and/or voltage accomplishes this.
Constant power occurs when a machine delivers the same output shaft power independently of the speed of rotation. Constant torque occurs when the relationship between power output and speed is constant. Variable torque is when the power output varies with speed (usually higher at higher speeds).
For AC machines, synchronous speed is proportional to frequency and number of poles. For DC machines, it is proportional to applied voltage (with constant field current), or to field current (with constant armature voltage).
Most search engines will give you a discussion on the electromagnetic design and the relevant connections for the two-speed consequent pole (Dahlander) machine.
Converting energy to motion for more than half a century
