DC generator equations
Hello,
I am using DC permanent magnet motor as a DC generator. I would like to calculate the estimated output voltage and current from the generator at known speeds. I already know the armature resistance and inductance for the motor. Do you know where can I find the equation?
Many thanks
I am using DC permanent magnet motor as a DC generator. I would like to calculate the estimated output voltage and current from the generator at known speeds. I already know the armature resistance and inductance for the motor. Do you know where can I find the equation?
Many thanks
Replies
-
narayana murthy#-Link-Snipped-#
i think this may help you -
freak16DC genarator are of various connections:
1) Separately exicted
2) DC shunt excitation
3) DC series excitation
4) DC componund excitation
DC permagnet is considered as equivalent to dc separately excited motor
considering the magnetism of magnet does not deteriorate with passage of time ( but it do go down with time) you can apply the equations for separately excited.
As NM mentioned.. -
Arpfreak is right
-
mibawadMany thanks for your reply. I would to know if I know the generator speed and the resistance and inductance values for the generator, and the back emf constant. Could I calculate the current and output voltage. I can't find this relation because I found that I have two unknown (I and V) in one equation. Is there two equations to calculate them.
-
narayana murthygenerator speed can be known from name plate details as i know
resistance and inductance can be calculated from v and I equations
I can be known from ammeter which is connected at output side -
freak16DC machine does not have inductance as far as i know.
We use the equation for generator
E (induced emf) = Vt(terminal voltage) + Ia * ra
Where E is directly proportional to speed
E = K w
W= speed of rotor
K can be found out from no of conductors parallel path and other parameters
Let me know if problem persists -
narayana murthy@freak: thanks freak iam forgotten as iam seeping about DC machines so i mentioned that
@mibawad: yes freak is right there is no concept of inductance in DC machines
inductance and capacitance only appears in AC machines because there is no alternating current in DC machines
inductance only appears at only there is a existence of alternating current -
mibawad@freak
What I want to say that for DC motor or generator:
Emf=V+Ia*Ra+La(di/dt)
Emf=K*w
If I know K, w, Ra and La, and I want to calculate V and I according to the speed w. I couldn't from this equation because the number of unknown is more than the number of equations. -
freak16Will dce machine is having inductance i strongly doubt..
And you need to know amout the load somehow..
you cant absolutely.. -
narayana murthyfreak is right we have no inductance in DC machines
E=V+(I*R)
there is no inductance -
mibawad@freak
Therefore, I couldn't calculate the current and voltage generated from the DC generator without knowing the load as well. Is that what do you want to say? -
freak16@mibawad
Yes buddy.. i am saying the same thing..
And without knowing supply voltage as well as load no engineer of world can do it..
Kiddingđ -
mibawadBut, there is no supply voltage for generator. It is only in case of DC motor
-
IES@freak: Yes there is inductance associated with the coils present in parallel paths,
which produces Reactance Voltage. -
lalWhat about this eqn : E = (fi)*Z*N*P/(60*A)
Fi - flux
Z - no. Of conductors
P - parallel paths
A - its value depends on winding. Eg: 2 for a simplex winding
This is the induced EMF. To get the terminal voltage the armature copper loss is subtracted. (Assuming its seperately excited) -
ganeshbalasti
#-Link-Snipped-# -
Akshay SinghI am thinking to build a generator with both rotor and stator rotating in this way relative speed between rotor and stator I.e N increase hence more electrical power
-
Akshay SinghAnyone online please help
-
Akshay SinghWhat no one answer here
You are reading an archived discussion.
Related Posts
Can anyone post details about labview projects.Just turn your look on labview...Its an one emerged software supplied by National Instruements.I guess most engineers will have scope on this labview...
Your...
âThere are 10 types of people in this world, those who understand binary and others who donât.â. You must have heard this phrase, isnât it? This is one of the...
what about embedded systems designing as a carrier?is there a bright scope of this field in india ?what are job apportunities?and finally the major question can an electrical and electronic...
Apple has finally launched iPad in India, officially. Here's price list of iPad in India -
iPad with Wi-Fi
16 GB: Rs. 27,900
32 GB: Rs. 32,900
64 GB: Rs....
Considering the fact the modern mantra, "Work hard, Party harder", a party after work to rejuvenate the mind is the "to do" thing.
My thought is if celebrations become regular...