Sinusoidal Airgap Flux Distribution

Question 1

Ampere’s Law

Answer 1

H is dependent on the number of conductors and therefore the number of turns for all coil enclosed by the flux path and the current flowing through it

Question 2

how to generate clean ac voltage,

Answer 2

magnetic flux in the airgap between rotor and stator to vary in a sinusoidal pattern as the rotor spins

Question 3

why sinosodoial flux

Answer 3

this produces a sinosoidal emf whihc is ideal for power systems (smooth V)

Question 4

whta creates teh flux

Answer 4

rotor has coils that create magnetic fields when a field current IF flows through ti

Question 5

what does H depend on

Answer 5

how much current IF is flowing thru
how many turns of wire each coil has

Question 6

You’re told there are:
5 coils on the rotor
2 coils with 𝑁1 turns (outer coils)
2 coils with 𝑁2 turns (middle coils)
1 coil with 𝑁3 turns (center coil)

All these coils are connected in series, meaning the same field current flows through each. how does flux density B1 B2 AND B3 flow for each

Answer 6

B1 - n1, n2, n3, IF outer
b2 - n2, n3, IF middle
b3 - n3, if - center

Question 7

how do we make the flux sininosoidal

Answer 7

adjust the number of turns in each coil, make center coil stronger that outer ones N3>N2>N1

change spacing between coils (slots)

Question 8

what happens if you change IF

Answer 8

all coils are serially connected so all experience the same change but it only chnages the manitude not the shape

Question 9

chaging IF

Answer 9

all the coils are serially connected, all coils will experience the same change in
𝑰𝑭. So, changing 𝐼𝐹 should only adjust the magnitude of the flux but the sinusoidal
variation of the airgap flux is still maintained.