From: John Turco on
Ron Hunter wrote:

<heavily edited, for brevity>

> Actually, many states don't have good frequency regulation. Some
> correct the frequency as infrequently as every three minutes. Clocks
> used on such power lines may be off by as much as 3 minutes a day! The
> ONLY state that closely regulates frequency to 60hz checked each second,
> is Texas, which is why we are NOT connected to the 'national power
> grid'. Connecting a closely regulated frequency power line at high
> voltage to another that is not closely regulated is a difficult, and
> expensive, proposition.


Hello, Ron:

Curious; does that have something to do with the Texas oil industry,
perhaps?


Cordially,
John Turco <jtur(a)concentric.net>
From: SMS on
Ron Hunter wrote:

> Actually, many states don't have good frequency regulation. Some
> correct the frequency as infrequently as every three minutes. Clocks
> used on such power lines may be off by as much as 3 minutes a day! The
> ONLY state that closely regulates frequency to 60hz checked each second,
> is Texas, which is why we are NOT connected to the 'national power
> grid'. Connecting a closely regulated frequency power line at high
> voltage to another that is not closely regulated is a difficult, and
> expensive, proposition.

When I took power engineering, many moons ago, they told us that the
_average_ frequency over time was almost exactly 60.0 Hz. If the
frequency went up a bit too high, they'd compensate by lowering it
slightly, and vice-versa. This was critically important for clocks, and
other timing devices.

Texas is connected to the national grid by high voltage DC lines, but
not by AC, so it's true that they maintain their on AC frequency. Kind
of weird how the country is about evenly divided into easter and western
grids, except for Texas (an AK and HI). Parts of Texas are on the
Eastern and Western grids, but not much of it.

See "http://www.slate.com/id/2087133/"
"http://www.ferc.gov/EventCalendar/Files/20070315110239-E-5-PR-rev.pdf"
From: Irwin Peckinloomer on
In article <46A02BDA.58B788FA(a)concentric.net>, jtur(a)concentric.net
says...
> Ron Hunter wrote:
>
> <heavily edited, for brevity>
>
> > Actually, many states don't have good frequency regulation. Some
> > correct the frequency as infrequently as every three minutes. Clocks
> > used on such power lines may be off by as much as 3 minutes a day! The
> > ONLY state that closely regulates frequency to 60hz checked each second,
> > is Texas, which is why we are NOT connected to the 'national power
> > grid'. Connecting a closely regulated frequency power line at high
> > voltage to another that is not closely regulated is a difficult, and
> > expensive, proposition.
>
Actually, the Texas grid is the least closely regulated of the 3 North
American grids, basically because it is the smallest. (All the
generators in a connected grid are frequency locked together. Since the
Texas grid is smaller, it has less combined inertia, and varies more.)
Even at its worst, this frequency variation is less than .025 Hertz, and
varies gradually, slowing during peak demand periods (i.e late afternoon
in summer) and gaining during low demand periods (i.e. early morning).
The only real effect is on clocks, since they accumulate any errors,
There would be no discernible effect on battery chargers. (Remember
battery chargers? They were the original subject of this thread,)
From: Ron Hunter on
John Turco wrote:
> Ron Hunter wrote:
>
> <heavily edited, for brevity>
>
>> Actually, many states don't have good frequency regulation. Some
>> correct the frequency as infrequently as every three minutes. Clocks
>> used on such power lines may be off by as much as 3 minutes a day! The
>> ONLY state that closely regulates frequency to 60hz checked each second,
>> is Texas, which is why we are NOT connected to the 'national power
>> grid'. Connecting a closely regulated frequency power line at high
>> voltage to another that is not closely regulated is a difficult, and
>> expensive, proposition.
>
>
> Hello, Ron:
>
> Curious; does that have something to do with the Texas oil industry,
> perhaps?
>
>
> Cordially,
> John Turco <jtur(a)concentric.net>

Nope, just choices made early on in the process of electrification, and
an effort to prevent brownouts, and blackouts. Texas does sell power to
Mexico, which I found somewhat surprising.
From: Ron Hunter on
SMS wrote:
> Ron Hunter wrote:
>
>> Actually, many states don't have good frequency regulation. Some
>> correct the frequency as infrequently as every three minutes. Clocks
>> used on such power lines may be off by as much as 3 minutes a day!
>> The ONLY state that closely regulates frequency to 60hz checked each
>> second, is Texas, which is why we are NOT connected to the 'national
>> power grid'. Connecting a closely regulated frequency power line at
>> high voltage to another that is not closely regulated is a difficult,
>> and expensive, proposition.
>
> When I took power engineering, many moons ago, they told us that the
> _average_ frequency over time was almost exactly 60.0 Hz. If the
> frequency went up a bit too high, they'd compensate by lowering it
> slightly, and vice-versa. This was critically important for clocks, and
> other timing devices.
>
> Texas is connected to the national grid by high voltage DC lines, but
> not by AC, so it's true that they maintain their on AC frequency. Kind
> of weird how the country is about evenly divided into easter and western
> grids, except for Texas (an AK and HI). Parts of Texas are on the
> Eastern and Western grids, but not much of it.
>
> See "http://www.slate.com/id/2087133/"
> "http://www.ferc.gov/EventCalendar/Files/20070315110239-E-5-PR-rev.pdf"

Well, Texas is rather wide, and positioned right in the middle of the
country, so I can see how it would be logical to divide it between east
and west. The far western part is even in a different time zone. But,
the connections between the Texas power grid and the rest of the country
are minimal, and the process a bit expensive, from what I have read. We
also generate more power from wind than any other state, even though
California and Hawaii get more recognition for this. We could generate
about twice what we do now if adequate transmission lines to the major
cities from the wind-farm sites were in place. Great planning, huh?