Page 693 - Basic Electrical Engineering

or,

(8.9)
or,

Thus, we see that the value of maximum torque, T is independent of rotor
m
resistance R but the slip at which maximum torque is developed changes
2
with value of R .
2

8.12 TORQUE–SLIP CHARACTERISTIC
The variation of torque with slip can be studied using the torque equation.

The shape of the torque–slip characteristic is predicted as follows:
Let us write the torque equation derived earlier. Referring to (8.7), we have

Let us assume R = 1 Ω and X = 8 Ω.
20
2
The value of S changes from 0 to 1. When the value of S is very small, say

0.01, 0.02, 0.03, 0.04, etc., the value of will be small as compared to .

Thus, for small values of S, we can write

or, T ∝ S