HIGHER HARMONICS

151

as the fundamental (except the single-phase third harmonic
above discussed, and its multiples, which have three times as

__JZl-m____JZ1_ T-'/,

FIG. 58.—Current and flux distribution in induction-motor air gap, with
different types of windings
many motor poles), but a lower synchronous speed, due to their
higher frequency.
Torque harmonics may also occur, having the fundamental