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an investigation of dual stator winding induction machines

an investigation of dual stator winding induction machines

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θ ,<br />

∂B1<br />

µ 0r<br />

= ⋅ J1<br />

θ<br />

∂θ<br />

g<br />

( , t)<br />

197<br />

(5.8)<br />

Then the flux density is obtained by integrating (5.8) with respect to the <strong>stator</strong> <strong>an</strong>gle<br />

µ 0r<br />

B = ∫ ⋅ J1(<br />

θ,<br />

t)<br />

⋅ dθ<br />

g<br />

1 (5.9)<br />

Substituting the expression <strong>of</strong> surface current distribution (5.5) into (5.9),<br />

( )<br />

( ) [ ( ) ] ⎬<br />

⎭ ⎫<br />

⎧ µ 0r<br />

j ω1t<br />

−P1 θ<br />

θ,<br />

t = Re j 2 3C<br />

⋅ I e<br />

B 1 ⎨<br />

s1<br />

s1<br />

(5.10)<br />

⎩ gP1<br />

The electric field induced at the <strong>stator</strong> surface is calculated by Faraday's Law. Since<br />

the air gap is z direction, the ch<strong>an</strong>ge only happens in the y direction:<br />

∂E<br />

∂B<br />

=<br />

∂y<br />

∂t<br />

Substituting (5.7) into (5.11),<br />

∂E<br />

∂θ<br />

∂B<br />

∂t<br />

1 1 = r = rB1<br />

⋅ jω1<br />

Then the electric field is expressed as:<br />

∫<br />

( θ t)<br />

E = jω<br />

⋅r<br />

⋅ B , ⋅dθ<br />

(5.11)<br />

(5.12)<br />

1 1 1<br />

(5.13)<br />

Substituting (5.10) into (5.13) <strong>an</strong>d integrating, the electric field due to the ABC<br />

<strong>winding</strong> set is given as:<br />

( )<br />

( ) [ ( ) ] ⎬<br />

⎭ ⎫<br />

2 ⎧ µ 0ω1r<br />

j ω1t<br />

−P1 θ<br />

θ,<br />

t = Re − j 2 3C<br />

⋅ I e<br />

E 1 ⎨<br />

2<br />

s1<br />

s1<br />

(5.14)<br />

⎩ gP1<br />

The electromotive-force (EMF) induced in the <strong>stator</strong> phase A c<strong>an</strong> be found by<br />

multiplying the electric field with the <strong>winding</strong> distribution <strong>of</strong> the phase A <strong>an</strong>d is given as:

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