Problem 3 (Textbook 4.3 and 4.6) Consider the two-phase device shown in Fig. 3.3. The windings are sinusoidally distributed, each with N equivalent turns. Express: (a) The turns density functions: Nas and Nbs (i.e., how the number of turns in each winding varies with position s). (b) The MMF associated with each winding: mmfas and mmfps (c) The net MMF in the air gap: mmf, (d) Determine the phase relationship between las and Ips that will produce counterclockwise rotation of mmfs. That is, state which is leading or lagging and by how many degrees. (e) Locate the positions of the stator north pole, NS, and the stator south pole, S5, when wet = 30° with las = √21,coswet and ins -√21,sin wet. Figure 3.3 ==1 as axis bs 8 as as bs' bs axis Elementary two-pole, two-phase electromechanical device.

Fig: 1