Previous in Forum: electrical knowledge   Next in Forum: IP 67 Enclosures
Close
Close
Close
9 comments
Rate Comments: Nested
Anonymous Poster

power factor

03/02/2009 7:24 AM

what is power factor?

Reply
Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.
Guru

Join Date: Mar 2007
Posts: 2550
Good Answers: 103
#1

Re: power factor

03/02/2009 8:07 AM

2n th post on this subject where n→ ∞,

read any book- ANY BOOK - on electrical engineering (circuit theory electrial machines, ...) preferably AC and not DC.

__________________
Fantastic ideas for a Fantastic World, I make the illogical logical.They put me in cars,they put me in yer tv.They put me in stereos and those little radios you stick in your ears.They even put me in watches, they have teeny gremlins for your watches
Reply
Anonymous Poster
#8
In reply to #1

Re: power factor

03/12/2009 10:29 AM

COSINE ANGLE BETWEEN THE VOLTAGE AND THE CURRENT IS THE POWER FACTOR

Reply
Guru
United Kingdom - Member - Indeterminate Engineering Fields - Control Engineering - New Member

Join Date: Jan 2007
Location: In the bothy, 7 chains down the line from Dodman's Lane level crossing, in the nation formerly known as Great Britain. Kettle's on.
Posts: 32175
Good Answers: 839
#2

Re: power factor

03/02/2009 10:21 AM

There is an excellent article on this topic in Wikipedia.

__________________
"Did you get my e-mail?" - "The biggest problem in communication is the illusion that it has taken place" - George Bernard Shaw, 1856
Reply
Guru

Join Date: Jul 2008
Location: SoCal USA
Posts: 556
Good Answers: 23
#3

Re: power factor

03/02/2009 9:54 PM

It could be a factor that has been lifting weights.

__________________
I do not 'know it all', but i will admit that I would like to. CJM
Reply Off Topic (Score 5)
Guru

Join Date: Mar 2007
Posts: 2550
Good Answers: 103
#4
In reply to #3

Re: power factor

03/02/2009 10:29 PM

Why not the one makes a democracy vs dictatorship (Power to the people Vs Power for One)

Or the factor that decides what portion of power is shared between the different arms of the pigs (refer Animal farm of Orwell for deinition of Pigs)

__________________
Fantastic ideas for a Fantastic World, I make the illogical logical.They put me in cars,they put me in yer tv.They put me in stereos and those little radios you stick in your ears.They even put me in watches, they have teeny gremlins for your watches
Reply Off Topic (Score 5)
Guru

Join Date: Jul 2008
Location: SoCal USA
Posts: 556
Good Answers: 23
#6
In reply to #4

Re: power factor

03/03/2009 11:57 AM

'power factor' often heard, mostly mis-understood. Deep, very deep, and the realization of the fullness is profound.

I propose we ask a series of mini questions (because I anticipate a great deal of right (but not quite right) posts, each question limited to one of the specific related features that will lead to a widespread profound conceptualization, knowledge with understanding, among the members of CR4 when completed.

Several can quote the math, some can draw the triangles, some can do the trig, some get that isosceles (takes 1 triangle) and not Pythagoras (takes 2 triangles) leads directly to the sqrt of 3, some get how the vectors relate across the spectrum, some understand capacitors, some get how induction works, motor start-up inrush (remember CEMF?), why motors have certain speeds (poles etc) but I still see posts that reveal that the BIG picture is a little fuzzy.

I wonder how many can draw all of the Wye, delta 3w, delta 4w and the single phase 240/120 (US) all on the same vector drawing at the same time? They do all derive from the same rotating (most anyway) generation source, and can all be drawn according to the point in time that they occur.

maybe something like this:

Since a current vector indicates the vector sum of the current through the resistance (Ω) at 00, and the var (reactive) current at 900, does that vector represent the actual timing and flow of current at that moment, or is it just a mathematical sum representing current flow at 2 other moments?

If 2 separate moments are answered, then the question "can current flow in 2 directions on the same wire at the same moment? (along with a sine wave showing the timing of each element).

Or in relation to induction:

What would happen to a copper conductor 5mm2 of 50m length, suspended in air with lots of clearance and insulators at the supported ends, if 4kV were introduced to the wire from a different line of the 4kV at each end. (4kV potential across the length).

Now we have the same conductor wound in a coil shape and add the 4kV. What happens? Why?

Maybe I'm getting off on a tangent, but we seem to get this question series often.

BTW I enjoy George O. Quite imaginative.

__________________
I do not 'know it all', but i will admit that I would like to. CJM
Reply Off Topic (Score 5)
Guru

Join Date: Mar 2007
Posts: 2550
Good Answers: 103
#7
In reply to #6

Re: power factor

03/04/2009 6:43 AM

I think we are going to cover total syllabus of Electrical (At least AC portion) of the circuits.

Because it starts from phasors (normally we call them though some may force the vector name also - due to time variance of phase and not exactly directions here- so the direction is n time and not space)

And end up in self inductance of wire, mutual inductances, mutual inductance of the coils of same wire, and so on.

To think again -- say we have a long wire coiled. So from end A to end B, the current will have a phase difference (even at a speed of C at which the field is established? ) will these two phase shifted currents interact with each other and change the effective inductance ? interesting thought but won't proceed on this will get a nobel (which I don't want )

But frankly, the easier parts may be left to themselves to study and let us interfere where it is genuinely required.

(BTW if you want start a blog, I hope that we may contribute to it)

__________________
Fantastic ideas for a Fantastic World, I make the illogical logical.They put me in cars,they put me in yer tv.They put me in stereos and those little radios you stick in your ears.They even put me in watches, they have teeny gremlins for your watches
Reply Off Topic (Score 5)
Associate
Engineering Fields - Power Engineering - New Member

Join Date: Nov 2007
Location: India
Posts: 42
Good Answers: 3
#5

Re: power factor

03/03/2009 12:38 AM

Dear guest,

In electrical engineering point of view power factor is ratio of useful power(KW) to power drawn from source(KVA). ie P.F=kw/Kva.Theoretically one will say that all power drawn from net work shall be used as useful power(KW).However due to inductive type of majority type of electrical loads, reactive power(KVAR) is also drawn from network .This reactive power (KVAR) does not contribute to useful power.Hence full power drawn from network (KVA) is not converted to useful power(KW).

Hence Power factor can be considered as efficiency of power utilisation.Higher power factor means higher usefulpower-Kw supplied and less reactive power consumed.

Lower Pf means lower useful power -kw supplied and large reactive power consumed.

The theoretical pf is 1.0 ie all power drawn (KVA) is converted to Full Kw.

In practical case the pf is always less than 1.0 due to reasons stated above.

Trust this clarifies your question

Regards

V.Ambarani

================================================================

__________________
Best Regards
Reply
Participant

Join Date: Apr 2009
Posts: 1
#9

Re: power factor

04/01/2009 5:41 AM

is a ratio of real power and apparent power. its equals to 1 when current and voltage are in phase and 0 where current leads or lags the voltage by 90 degree.

Reply
Reply to Forum Thread 9 comments
Copy to Clipboard

Users who posted comments:

Anonymous Poster (1); CJMcGill (2); mahlanta (1); PWSlack (1); sb (3); V.Ambarani. (1)

Previous in Forum: electrical knowledge   Next in Forum: IP 67 Enclosures

Advertisement