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an investigation of dual stator winding induction machines

an investigation of dual stator winding induction machines

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Since small <strong>machines</strong> typically have lower value <strong>of</strong> gap flux density th<strong>an</strong> large<br />

<strong>machines</strong>, the peak fundamental air gap flux density B 4 for the 4-pole <strong>induction</strong> machine<br />

is finally chosen to be 0.8 Tesla. Then the air gap flux densities for each <strong>stator</strong> <strong>winding</strong><br />

are:<br />

B<br />

B<br />

2<br />

6<br />

=<br />

=<br />

0.<br />

16<br />

0.<br />

718<br />

Tesla<br />

Tesla<br />

53<br />

(2.16)<br />

The air gap flux density <strong>an</strong>d the yoke flux <strong>of</strong> the <strong>dual</strong> <strong>stator</strong> <strong>winding</strong> <strong>induction</strong><br />

machine are shown in Figure 2.3 <strong>an</strong>d Figure 2.4 respectively. The air gap flux density <strong>an</strong>d<br />

the yoke flux <strong>of</strong> the 4-pole <strong>induction</strong> machine are also shown for the comparison. The<br />

result clearly shows that the <strong>dual</strong> <strong>winding</strong> machine design does achieve the same peak air<br />

gap flux density <strong>an</strong>d yoke flux as the 4-pole <strong>induction</strong> machine.<br />

2.2.3 Number <strong>of</strong> Turns per Phase<br />

The EMF generated in the armature <strong>winding</strong> c<strong>an</strong> be expressed as:<br />

E = 4.<br />

44 fK N φ<br />

(2.17)<br />

1<br />

s<br />

m<br />

where, f is the frequency <strong>of</strong> the input voltage; 1 K is the <strong>stator</strong> <strong>winding</strong> factor; N s is the<br />

number <strong>of</strong> turns per phase <strong>an</strong>d φ m is the magnetic flux per pole. If the voltage across the<br />

<strong>stator</strong> resist<strong>an</strong>ce is negligible, the EMF will be equal to the input voltage. The only<br />

unknown in the above is the turns per phase N s , hence its value c<strong>an</strong> be expressed as:

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