Power Electronics And Drive

Dear Engineers

I have a problem for design and improvement.

A 3-phase Induction motor, 8-poles, 60-Hz, 440V operated in a V/F control mode, The stator resistance is 0.14 ohms, Assume that operation is at rated frequency and voltage to deliver Maximum Torque of 1000N-m, and that the rotor resistance is 0.21 ohms.

1) How to find the leakage inductance of the motor's equivalent circuit?

2)How to calulate the minimum frequency which still allows the motor to reach maximum torque?

Friends please give your valuable guidance to work out this problem and If possible please suggest me which formula i have to use, I have already referred some of the books, Your valuable suggestion is highly appreciated.

thanks and best regards

sreeram