The expression for the torque of an induction motor as a function of its slip may be obtained by application of Thevenin's theorem to the circuit model. Show that the Zth obtained can be shown to be approximately equal to Zth = R1+JX1, where X1=X1 and
R1= r1(Xm/(X1+Xm))^2.
Find the expression for the slip at which maximum torque occurs and the expression for the subsequent maximum torque at the maximum slip. Please show all calculations for the exact expressions explicitly. List your assumptions and rationale for aprroximations used.