Induction machine: Question regarding field weakening region limited by breakdown torque
It is pretty obvious that the range that is being described is the range at which the transmitted torque is limited to the breakdown torque. The entry point for that operation is the point at which the torque for the constant power operation is equal to the breakdown torque. The torque for constant power operation is given by T = P/w where the power is the power developed at maximum torque and w for the point at which the torque begins to decline. You need the formula for breakdown torque. I believe that it is proportional to the square of w at the point at which it begins to decline divided by w. T is torque in Nm. P is power in watts. w is speed in radians per second.