27.02.2013 Views

an investigation of dual stator winding induction machines

an investigation of dual stator winding induction machines

an investigation of dual stator winding induction machines

SHOW MORE
SHOW LESS

Create successful ePaper yourself

Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.

has to be modified to adapt to these ch<strong>an</strong>ges. The challenge is how to avoid the deep<br />

saturation problem when the designed <strong>dual</strong> <strong>stator</strong> <strong>winding</strong> <strong>machines</strong> are working under<br />

different load conditions. The <strong>an</strong>swers lie in finding a proper way to evaluate the flux<br />

density for the <strong>dual</strong> <strong>stator</strong>-<strong>winding</strong> machine <strong>an</strong>d design the flux density for each <strong>stator</strong><br />

<strong>winding</strong>. This import<strong>an</strong>t issue for the <strong>dual</strong> <strong>stator</strong>-<strong>winding</strong> machine has been addressed in<br />

few papers.<br />

In [2.1], the author discusses this issue for a specific example, however the general<br />

conclusions are not presented. In [2.2], the author lists three methods that c<strong>an</strong> be used to<br />

evaluate the magnetic flux density <strong>of</strong> a BDFM. The first method is a conservative one, in<br />

which the peak value <strong>of</strong> flux density <strong>of</strong> the <strong>dual</strong> <strong>stator</strong>-<strong>winding</strong> machine c<strong>an</strong> be found by<br />

adding the peak values <strong>of</strong> flux densities <strong>of</strong> two <strong>stator</strong> <strong>winding</strong> sets together. In the second<br />

approach, the combined magnetic loading is defined as the square root <strong>of</strong> two<br />

components. It has been shown in [2.2] that the value <strong>of</strong> the combined flux density<br />

obtained by the second approach will be much less th<strong>an</strong> the value obtained from the first<br />

one. The last evaluation method was proposed by the author in [2.2], which is called a<br />

new generalized method. The results show that the value <strong>of</strong> the magnetic loading<br />

obtained by the third method are independent <strong>of</strong> pole number combinations <strong>an</strong>d <strong>of</strong>fset<br />

<strong>an</strong>gles, except one special case-- p = , p = 4 . The magnetic loading calculated by the<br />

1<br />

2 2<br />

proposed method is close to the second approach <strong>an</strong>d the adv<strong>an</strong>tages <strong>an</strong>d disadv<strong>an</strong>tages<br />

<strong>of</strong> these two methods have been addressed in [2.2]. It should be noted, however, that all<br />

the methods c<strong>an</strong> only be used to evaluate the combined magnetic loading <strong>an</strong>d c<strong>an</strong> not be<br />

used to determine the magnetic loading for each <strong>stator</strong> <strong>winding</strong> set.<br />

9

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!