
142 Electric Motors and Drives
what governs the speed of rotation and the magnitude of the
field, which are the two factors that most influence motor
behaviour.
Having established how the rotating field is set up, and
what its speed and strength depend on, we move on to
examine the rotor, concentrating on how it behaves when
exposed to the rotating field, and discovering how the torque
varies with speed. In this section we assume - again for the
sake of simplicity - that the rotating flux set up by the stator
is not influenced by the rotor.
Finally we turn attention to the interaction between the
rotor and stator, verifying that our earlie