‘Sum’ and ‘difference’ winding modulation with special reference to the design of 4/6-pole p.a.m. windings

A novel 16/6 phase modulated winding

“…To obtain the required two speed winding a standard 16 pole winding was first selected and the modulated 6 pole winding was then derived through the use of three steps of phase modulation [6] together with the slot vector diagram [7]. Fig.…”

“…For the chosen 16/6-pole case, the PAM winding obtained using the sum modulation [7] is found to be not practical because of the predominated 7th harmonic as may be seen from Table I and Fig. 3.…”

“…Comparison is therefore made between PM winding and PAM winding using difference modulation [7], whose winding connection is shown in Fig. 4.…”