[time-nuts] Line Frequency standard change - Possible ?

Didier Juges shalimr9 at gmail.com
Sat Feb 11 13:25:59 EST 2017

One issue with power factor corrected power supplies is that in the short
term (as a minimum, at the line frequency), they do behave like resistors
(current goes up when voltage goes up) but as they have a slow voltage
regulation loop to provide regulated output, they do behave like constant
power loads to the grid in the long term. The transition between the two
modes of operation is not always smooth and can lead to instabilities when
combined with the generator's response and the line impedance.
I had this particular problem with a 5kW PFC corrected power supply that
was working fine by itself but caused line oscillations when 16 of them
were running in parallel.

On Feb 11, 2017 4:04 AM, "David" <davidwhess at gmail.com> wrote:

> On Thu, 9 Feb 2017 19:06:51 -0500, you wrote:
> >One simplistic way to look at all this is that a switcher presents a
> “negative
> >resistance” load. If you drop voltage, current goes up. OCXO’s happen
> >to share this issue. Negative resistances are *not* what most power source
> >guys want in their control loop.
> >
> >Bob
> People working with emitter/source followers do not like it either and
> I cannot see the folks using inverters wanting to pay to put big
> resistive heaters across the grid to compensate.
> Adding power factor correction to switching power supplies was cheap
> compared adding "negative resistance" correction.
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/m
> ailman/listinfo/time-nuts
> and follow the instructions there.

More information about the time-nuts mailing list