US Power frequency to stability to be relaxed

[1audio]

The entity that is responsible for maintaining the power line frequency is planning to relax the standards. This means that clocks that run on the AC line will not keep good time. It also means that turntables and tape recorders that run off the AC line with hysteresis synchronous motors may have more significant speed variations. It may not be enough to matter but who knows?

More here: TEC Elimination

[abraxalito]

How much power (as a percentage) is generated by fossil fuels in USA? Wonder if this declaration has any connection at all with the draw-down on the petroleum reserves?

[BrianL]

I do not see how fluctuation of North American power line frequency is at all related to tapping some of the strategic petroleum reserve. Those two would seem no more related than line frequency is to my tire pressure.

Demian, it would seem that a well-functioning power grid would push them to tighter frequency control. Curious...

[Pano]

It may have to do with wind power and such. It's hard to keep clocked, or so say the power guys I know.

[1audio]

The first problem is that the grid slows down when it gets loaded, just a little but it does. The question is whether to continue the practice of speeding it up when lightly loaded to get the clocks back to the correct time. The max fluctuation seems to be about .1% which may not be audible under any circumstances but who knows?

[abraxalito]

Originally Posted by BrianL

I do not see how fluctuation of North American power line frequency is at all related to tapping some of the strategic petroleum reserve.

Sure, just one of those crazy leaps of faith I make sometimes. If the grid's going to be more unstable in future (with relaxed frequency tolerances) that might be because they know of some pending fuel shortages. That's all.

[prairiemystic]

I worked in the electric utility industry for several years. Substations have UFLS "under-frequency load shedding" on their protective relays. If the grid frequency drops a couple hertz, breakers open and dump load to keep the grid stable.
With wind farms and solar power coming, I think they have to loosen up these settings.

[DF96]

Maybe I have misread it, but it seems they are aiming at better short-term frequency control at the expense of worse long-term frequency control. It appears that the need to keep clocks correct (on average, over 24hours) is causing them to sometimes drop the frequency too low so they are proposing removing or relaxing the clock requirement.

This should mean that the synchronous motor in your turntable is more likely to run near the correct speed, but your clocks may be less accurate. I guess it depends on whether you listen to a lot of music, or have lots of planes/trains to catch.

[pinkmouse]

Who on earth still has clocks that sync to mains frequency? The last one I remember seeing was at my Nan's in the '70s!

[DF96]

Clocks on kitchen appliances are likely to sync to mains rather than a quartz crystal. This is cheaper, as you save the cost of a crystal and some frequency dividers, and it has better long-term stability (in the UK at least).