19.06.2015 Views

WIND ENERGY SYSTEMS - Cd3wd

WIND ENERGY SYSTEMS - Cd3wd

WIND ENERGY SYSTEMS - Cd3wd

SHOW MORE
SHOW LESS

You also want an ePaper? Increase the reach of your titles

YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.

Chapter 9—Wind Power Plants 9–38<br />

(c) P = 625 W; (d) I c =20/90 o A, I 1 =15/0 o A, pf = 1; (e) E = 268.79/9.64 o , P = 225 W;<br />

(e) reduces reactive power requirement and reduces power line loss.<br />

5.7 I = 231.3/ − 25.84 o A, E = 4009.0/31.10 o , δ =31.10 o , P = 962.9 kW/phase, ohmic losses<br />

= 17.65 kW.<br />

5.11 X s,pu,new =6.01<br />

5.18 R a = 0.00479 days/year or about 1 day in 209 years.<br />

6.2 (a) I a = 12.83 A; (b) k e = 0.383; (c) X s = 4.91 Ω; (d) 16 percent decrease.<br />

7.2 The 14-ft-diameter propeller and 2.5-in.-diameter cylinder clearly meet the requirements.<br />

The 12-ft-diameter propeller and 2-in.-diameter cylinder will probably be quite satisfactory<br />

at a lower cost.<br />

7.4 (a) n s = 350; (b) P m = 19,260 W = 25.83 hp.<br />

7.5 h 2 = 416 ft, Q 2 = 113 gal/min, P m2 = 12.66 kW<br />

8.1 $862<br />

8.3 13 units<br />

8.5 P v = $44.88. You should buy the cover.<br />

8.7 P v,X = $12,275.92, P v,Y = $12,551.84. You should buy machine X.<br />

Wind Energy Systems by Dr. Gary L. Johnson November 21, 2001

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

Saved successfully!

Ooh no, something went wrong!