Transcript Multipolar Machines Space and Electrical Degrees

Multipolar Machines
Space and Electrical Degrees
Stator is marked off in “space, or mechanical degrees”
Rotor at 0 reference, moves to 45 “electrical” degrees
Electrical degrees = (space degrees)(P/2)
P = # of poles
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How does the flux change
as the rotor turns?
• As the rotor turns through 180 mechanical
degrees, the flux traces out 360 electrical
degrees – in one revolution, 2 cycles of flux
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Frequency of the flux wave
Pn
2
f  frequency (Hz )
f 
P  number  of  poles
n  rotational  speed (rev / s )
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Four-Pole Generator
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