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an investigation of dual stator winding induction machines

an investigation of dual stator winding induction machines

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* 3<br />

*<br />

( V I ) V Re(<br />

M I )<br />

3<br />

P p = Re qds1<br />

qds1<br />

= dc qds1<br />

qds1<br />

(8.16)<br />

2<br />

4<br />

* 3<br />

*<br />

( V I ) V Re(<br />

M I )<br />

3<br />

P q = Re qds2<br />

qds 2 = dc qds 2 qds 2<br />

(8.17)<br />

2<br />

4<br />

Then the output power ratio coefficient K between the 2-pole ABC <strong>winding</strong> set <strong>an</strong>d<br />

the 6-pole XYZ <strong>winding</strong> set is expressed as:<br />

* ( M qds2I<br />

qds2<br />

)<br />

* ( M I )<br />

Pq<br />

Re<br />

Pp<br />

1<br />

K = =<br />

, = = α<br />

P Re<br />

P + P 1+<br />

K<br />

p<br />

qds1<br />

qds1<br />

p<br />

q<br />

289<br />

(8.18)<br />

The rotor flux terms are eliminated in equation (8.11), <strong>an</strong>d the equation expressed in<br />

terms <strong>of</strong> the <strong>stator</strong> fluxes is substituted in (8.15). This results in <strong>an</strong> equation that<br />

expresses the required excitation <strong>of</strong> each <strong>winding</strong> set in terms <strong>of</strong> the magnetizing flux<br />

linkage using the magnitude <strong>of</strong> the modulation index as a measure <strong>of</strong> the excitation.<br />

M<br />

M<br />

2<br />

1<br />

2<br />

2<br />

− 2<br />

=<br />

3R<br />

L<br />

( 1+<br />

K )<br />

− 2K<br />

=<br />

3R<br />

L<br />

( 1+<br />

K )<br />

⎧ ⎡<br />

⎪ ⎢ s1<br />

⎪<br />

Re⎨2<br />

⎣<br />

⎪ ⎡ Lr<br />

⎪ ⎢<br />

⎩ ⎣ L<br />

⎧ ⎡<br />

⎪ ⎢ s<br />

⎪<br />

Re⎨2<br />

⎣<br />

⎪ ⎡ L<br />

⎪ ⎢<br />

⎩ ⎣ L<br />

( A − jω<br />

)<br />

1<br />

δ1<br />

+<br />

L<br />

e1<br />

δ1<br />

( A − jω<br />

)<br />

2<br />

r 2<br />

δ 2<br />

+<br />

L<br />

e2<br />

δ 2<br />

B ⎤ ⎫<br />

s1Br1<br />

− ⎥ ⎪<br />

Ar1<br />

− jωs1<br />

⎦ ⎪<br />

⎬<br />

L B ⎤<br />

( ) ⎪ ⎪<br />

m1<br />

r1<br />

⎥<br />

A − jω<br />

r1<br />

s1<br />

⎦<br />

⎭<br />

B ⎤ ⎫<br />

s2B<br />

r 2 − ⎥ ⎪<br />

Ar<br />

2 − jωs<br />

2 ⎦ ⎪<br />

⎬<br />

L B ⎤<br />

( ) ⎪ ⎪<br />

m2<br />

r 2<br />

⎥<br />

A − jω<br />

where, ω is the slip frequency <strong>of</strong> the 2-pole ABC <strong>winding</strong> set <strong>an</strong>d s1<br />

s2<br />

r 2<br />

s2<br />

⎦<br />

⎭<br />

(8.19)<br />

(8.20)<br />

ω is the slip<br />

frequency <strong>of</strong> the 6-pole XYZ <strong>winding</strong> set. The other variables are defined as follows:<br />

A<br />

r<br />

L<br />

si ri<br />

si = ,<br />

Lδ<br />

i<br />

A<br />

r L<br />

ri si<br />

ri = ,<br />

Lδ<br />

i<br />

B<br />

− r L<br />

i mi<br />

si = ,<br />

Lδ<br />

i<br />

B<br />

− r<br />

L<br />

ri mi<br />

ri = , 1 or 2<br />

Lδ<br />

i<br />

i = .<br />

Magnetizing flux linkage saturation reflected in the values <strong>of</strong> the magnetizing<br />

induct<strong>an</strong>ces <strong>of</strong> the machine (Figure 8.2) has <strong>an</strong> influence on the converter excitation

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