Re: Power Factor Correction weirdness?

To: tesla-at-pupman-dot-com
Subject: Re: Power Factor Correction weirdness?
From: Terry Fritz <twftesla-at-uswest-dot-net>
Date: Fri, 11 Feb 2000 12:35:44 -0700
Approved: twftesla-at-uswest-dot-net
Delivered-To: fixup-tesla-at-pupman-dot-com-at-fixme
In-Reply-To: <m12Izqg-0002o5C-at-elle.wnp.ac.nz>
References: <4.1.20000209185110.00a66880-at-pop.dnvr.uswest-dot-net> <B4C6530C.16E2%adamsmith-at-mediaone-dot-net>

At 09:04 AM 02/11/2000 +1200, you wrote:
>Hi Terry ;)
>
snip...
>> 
>> Cpfc = ( Vo x Vi ) / ( 2 x pi x f x Vi^2 )
>> 
>> Where
>> 	Cpfc = Power factor cap value in Farads
>> 	Vo = Rated NST output voltage in volts
>> 	Vi = Rated NST output current in amps
>> 	pi = 3.14159...
>> 	f = AC line frequency (50 or 60Hz)
>> 	Vi = AC input voltage (120 VAC)
>> 
>> For a 15kV/60mA transformer you get:
>> 
>> ( 15000 x 0.06 ) / ( 2 x 3.14159 x 60 x 120 x 120 ) = 165.8uF
>> 
>> To get "exact" you have to take all the non linearities, timing, and such
>> into account which is a few orders of magnitude harder but this equation
>> seems to do fine...
>> 
>> Comments, suggestions,...
>
>only one - it would be useful to use I for current instead of V  :)
>
>Regards,
>Malcolm
>

Hi Malcolm,

	I was just following our long standing Tesla list tradition of never being
able to get a posted equation right the first time no matter how hard one
tries ;o))  It was written correctly in my notes and everything....  My
second attempt at the equation follows...

 Cpfc = ( Vo x Ii ) / ( 2 x pi x f x Vi^2 )
 
 Where
 	Cpfc = Power factor cap value in Farads
 	Vo = Rated NST output voltage in volts
 	Ii = Rated NST output current in amps
 	pi = 3.14159...
 	f = AC line frequency (50 or 60Hz)
 	Vi = AC input voltage (120 VAC)


Cheers,

	Terry

References:

Re: Power Factor Correction weirdness?

From: Terry Fritz <twftesla-at-uswest-dot-net>