Figure 4.13: The distributed winding with 2 magnetic pole-pairs
For the motor shown in Figure 4.9, the conductors A + and A − are actually
the two sides of a distributed winding. The winding is redrawn in Figure 4.14.
The part of the coil in the area B is called effective coil and its length is about
the same as the length of the stator core. The part of the coil in areas A and
C are known as “end coil”. For design and analysis of an electric motor, the
effective coils are considered as the part of the coil structure that contribute
to the EM torque for the electromechanical energy conversion to take place,
whereas the end coils are the conductors required to form a closed electric
circuit but do not contribute to the EM torque.
Figure 4.14: One-phase distributed winding
According to equation 4.31, the MMF generated by the windings can be
considered the result of the sum of MMF harmonics, and its fundamental one