I

18 ELECTRICAL APPARATUS

and, substituting (3) and rearranging, gives:

(5)

or, absolute:

(TI + sro)2 +

The torque of the motor is:

T =
and, substituting (4) and (6):

y = ________

(6)

+ 5r0)2 +

+ SXQ —

(7)

As seen, this torque is a maximum in the range of slip, s,
where the second term in the denominator vanishes, while for
values of 5, materially differing therefrom, the second term in the
denominator is large, and the torque thus small.

That is, the motor regulates for approximately constant speed
near the value of s, given by:

SXi + SXo-----= 0,

s '

that is:

(8)

and So = 1, that is, the motor gives maximum torque near
standstill, for:
* = Xo + XL (9)
13. As instances are shown, in Fig. 8, the speed-torque curves
of a motor of the constants:
7o = 0.01-0.1 j,
£0 = Zi = 0.1 + 0.3 j,