Re: PFC for pigs

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Malcolm Watts by way of Terry Fritz <twftesla-at-qwest-dot-net>" <m.j.watts-at-massey.ac.nz>

Hi Greg,

On 3 Dec 2002, at 22:35, Tesla list wrote:

 > Original poster: "Gregory Peters by way of Terry Fritz 
<twftesla-at-qwest-dot-net>" <s371034-at-student.uq.edu.au>
 >
 > Hello list,
 >
 > I realise PFC for pole pigs is not necessarily practical for two
 > reasons:
 >
 > 1. Huge capacitance needed
 >
 > 2. Variable ballasting means no set value can be used.
 >
 > However, I assume SOME PFC is better than NONE, and I have just been
 > offered HEAPS of big motor run caps at a good price. Also, once my
 > coil is going properly, the ballast is not altered. So two questions:
 >
 > 1. How does one figure out an approximate value of capacitance needed?
 >
 > 2. Should the PFC go before the variac and ballast, or before the pig?
 >
 > I ask this question because I want to extract the most possible from
 > my measly 32A, 240v supply (The largest single phase residential
 > supply you can get in Australia, before going to 3 phase). Jeez I
 > wish I lived in the US! I'm one day going to wind a 415v to 240v
 > transformer and use two phases of my 32A 3 phase supply, but that's
 > in the future :)

If it is to be applied, it must be directly across the mains (before
everything else). The idea is modify what the mains "sees". Of
course, if what the mains is going to see varies, you can't use a
fixed value as you say. In industrial plants, PFC is applied
dynamically to meet varying load conditions.

Regards,
malcolm

 >
 > Cheers,
 >
 > Greg.
 >
 >
 >