How Does PF Change in an overexcited Synchronous Motor
How Does PF Change in an overexcited Synchronous Motor
(OP)
I am trying to figure out why, and more precisely how, the power factor is affected by a synchronous motor. My model is an input voltage source in series with a resistance and a negative voltage source representing the back EMF. I also am choosing insignificant inductance such as a servo might present, also because I'm trying to keep it simple. I notice that as the rotor position (phase difference between stator and armature) advances from the 90 degree position (max torque) to the 0 degree position (no torque), that the summed voltage (resultant) lages the input waveform from 0 to 90 degrees. I sort of thought that the resultant voltage waveform would tell me something about the current waveform which I expected to lead the input wave - not lag it.





RE: How Does PF Change in an overexcited Synchronous Motor
http://www.faculty.uaf.edu/ffrww/ee303/Fall2001/Labs/e3...
for Synchronous Motor V-curves
http://www.reliance.com/mtr/pwrfcrmn.htm
for Synchronous Motor power factor correction
RE: How Does PF Change in an overexcited Synchronous Motor
1. Overexcited
Current Ia drawn by the motor is leading motor terminal voltage
2. Underexcited
Current Ia drawn by the motor is lagging motor terminal voltage
Reference:
1. William D. Stevenson, Jr., Elements of Power System Analysis," Third Edition, McGraw-Hill, 1975, Figure 9.6 on page 218
RE: How Does PF Change in an overexcited Synchronous Motor
Also, I've checked my local library. Do know of a site where I might find fig. 9.6 ? Thanks for the pointer.
RE: How Does PF Change in an overexcited Synchronous Motor
http://www.tpub.com/content/doe/h1011v4/css/h1011v4_34....
RE: How Does PF Change in an overexcited Synchronous Motor
http://www.tech.purdue.edu/eet/courses/e...
RE: How Does PF Change in an overexcited Synchronous Motor
http://www.tech.purdue.edu/ecet/courses/eet331/331lc05....
If it truncates type in "/eet331/331lc05.pdf" after ../courses
RE: How Does PF Change in an overexcited Synchronous Motor
arc tan X(sub)L/R Sound right?
RE: How Does PF Change in an overexcited Synchronous Motor
Does you comment mean that you are no longer interested in additional responses?
RE: How Does PF Change in an overexcited Synchronous Motor
M. G. Say "Alternating Current Machines," John Wiley & Sons, 1978, Section 10 Synchronous Machine: Theory and Performance on Page 366...
Focus on the Excitation Voltage, Operating Characteristics, Equivalent Circuits, and relationships
P1=-(V1/Xa) Et sin(d)..............Eq10.1
Q1=(V1/Xa) [Et cos(d) - V1]....Eq10.2
RE: How Does PF Change in an overexcited Synchronous Motor
It sounds like I need to find a copy of "Alternating Current Machines" but have run out of options at this juncture. Thanks for sticking with me on this one!
RE: How Does PF Change in an overexcited Synchronous Motor
"Electric Machinery and Control"
Author: Irving L. Kosow,
Publisher: Prentice-Hall Inc., 1964
LoCCCN: 64-22802.
If you have difficulty contact me: EpsiconInc@aol.com
RE: How Does PF Change in an overexcited Synchronous Motor
http://s1.amazon.com/exec/varzea/preorder/new/047015133...