
152 Electric Motors and Drives
not all the flux produced by the rotor currents (see later)
links the stator, but some the rotor leakage flux links only
the rotor conductors.
On the face of it these leakage fluxes would seem to be
unwelcome imperfections, which we should go out of our
way to minimize. However whilst the majority of aspects of
performance are certainly enhanced if the leakage is as small
as possible, others (notably the large current drawn from the
mains when the motor is started from rest) are made much
worse if the coupling is too good. So we have the somewhat
paradoxical situation in which the designer finds it compara-
tivel ...