Dr. Ahmed G. Abo-Khalil

Electrical Engineering Department

field weakening

Operation of the motors above rated nameplate speed (base speed) is possible, but is limited to conditions that do not require more power than the nameplate rating of the motor. This is sometimes called "field weakening" and, for AC motors, means operating at less than rated V/Hz and above rated nameplate speed. Permanent magnet synchronous motors have quite limited field weakening speed range due to the constant magnet flux linkage. Wound rotor synchronous motors and induction motors have much wider speed range. For example, a 100 hp, 460 V, 60 Hz, 1775 RPM (4 pole) induction motor supplied with 460 V, 75 Hz (6.134 V/Hz), would be limited to 60/75 = 80% torque at 125% speed (2218.75 RPM) = 100% power. At higher speeds the induction motor torque has to be limited further due to the lowering of the breakaway torque of the motor. Thus rated power can be typically produced only up to 130...150% of the rated nameplate speed. Wound rotor synchronous motors can be run at even higher speeds. In rolling mill drives often 200...300% of the base speed is used. The mechanical strength of the rotor limits the maximum speed of the motor.

Office Hours

Monday 10 -2

Tuesday 10-12

Thursday 11-1

My Timetable

Contacts


email: [email protected]

[email protected]

Phone: 2570

Welcome

Welcome To Faculty of Engineering

Almajmaah University

IEEE

Institute of Electrical and Electronics Engineers

http://www.ieee.org/

http://ieeexplore.ieee.org/Xplore/guesthome.jsp

http://ieee-ies.org/

http://www.ieee-pes.org/

http://www.pels.org/

Links of Interest

http://www.utk.edu/research/

http://science.doe.gov/grants/index.asp

http://www1.eere.energy.gov/vehiclesandfuels/

http://www.eere.energy.gov/


القران الكريم

http://quran.muslim-web.com/

Travel Web Sites

http://www.hotels.com/

http://www.orbitz.com/

http://www.hotwire.com/us/index.jsp

http://www.kayak.com/

Photovoltaic Operation


Wave Power

World's Simplest Electric Train



PeltierModule-JouleThief-Fridge

homemade Aircondition

Salt water battery


إحصائية الموقع

عدد الصفحات: 2880

البحوث والمحاضرات: 1292

الزيارات: 48458