{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

Exam_4_Solution

# Exam_4_Solution - NAME jam 7 0R STUDENT NUMBER ECE 320 EXAM...

This preview shows pages 1–4. Sign up to view the full content.

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: NAME jam 7/ 0R STUDENT NUMBER: April 16, 2008 ECE 320, EXAM 4 Spring 2008 Problem 1 A 64—pole Y—connected synchronous generator is rated SOMVA, ZOkV, pf = 0.85 lagging, Ip/if z 25 and it has Lrn :1989 mH. 1:) {m t: :7. 5J1 3. Calculate the rated stator current and field current. Draw the corresponding phasor diagram for this operating point. i ' 4 —3/. '0 2% .50 /0 F ‘ [J7 \$5727 A J;=/c/95 A \0 b. Suddenly all the power to the generator is removed, the generator is still connected to the same power system of ZOkV and the field current remains unchanged (rated). What will be the stator current and the power factor? Include phasor diagram in your solution. 7’ = 5V3 19 cos '3’ "‘0 "3 (2° : qoo 5‘9) mo ._. t3“ —— * —-— Tar-2:210 a ) .Lm: IBHO A 11;;— ﬁlm-{,2 PI; —-— O Problem 2 A BLDC machine is supplied from 120V and under mechanical load at 1800 RPM draws 17A of current. The same machine operated from 120V and no—load will Spin at 3133 RPM. a. What is the resistance of the machine and torque at the given load? (neglecting friction) . 2‘1? @ no Load V: Wk ‘20 V: —‘—E‘O‘—‘ l6; M:O./5(-9é7 v6 Tzk : 0.36647- "1622“;41 @ Legal V: UL +1043 =3 iaovzt‘i-R+o%°l§‘é Re- 3-51— b. What is the no-and torque? (neglecting friction) @ no Lead Po "Tau Problem 3 a. What is the purpose of field weakening mode in PMAC motors? to ofcrcﬁe Aha, madmxﬂa CZX‘ hqher b. List one advantage and one disadvantage of PMAC machine versus 1M. @ [/3166 [MK Fﬂf' @ Offf/Céfgié like “Va/4:5. , ...
View Full Document

{[ snackBarMessage ]}

### What students are saying

• As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

Kiran Temple University Fox School of Business ‘17, Course Hero Intern

• I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

Dana University of Pennsylvania ‘17, Course Hero Intern

• The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

Jill Tulane University ‘16, Course Hero Intern