It hertz when you do that – power grid to stop regulating 60 Hz frequency

Watts Up With That? ^ | June 25,2011 | Anthony Watts

[brityank]

It hertz when you do that – power grid to stop regulating 60 Hz frequency

Posted on June 25, 2011 by Anthony Watts

“Experiment” on the US power grid will change the way some clocks and other equipment function.

A 60 hertz sine wave, over one cycle (360°). The dashed line represents the root mean square (RMS) value at about 0.707 Image: Wikipedia)

Story submitted by Joe Ryan

The AP has released an “exclusive” story concerning the nationwide “experiment” that will be conducted on the US power grid. The experiment will relieve the power providers from the duty of regulating the frequency of power on the line.

Normally the power stations condition their power to a frequency of 60 cycles a second, a frequency that many old clocks use to maintain their time. With the new standard, or lack of standard, these clocks will stop keeping time properly.

But the problem is more than that.

First, we have this gem from Joe McLelland who heads the Federal Energy Regulatory Commission (from AP article):

“Is anyone using the grid to keep track of time?” McClelland said. “Let’s see if anyone complains if we eliminate it.”

… forgive me for not getting warm fuzzies from this. Likewise, Demetrios Matsakis, head of the time service department at the U.S. Naval Observatory, had this to say (AP Article again):

“A lot of people are going to have things break and they’re not going to know why,”

So, we have what appears to be an untested, for the hell of it, “experimental” major change to the US electrical grid coming in a few weeks and those in charge aren’t really sure how it will work or if it may break something?

Not only is this what a LAB is for, but it is also something that the Federal Government should be TELLING people about in advance, and not in an AP “exclusive” press release.

[Erasmus]

I doubt that you will have to. With today's electronics, I think many of them have a built in timing reference, like a 32 khz crystal. It's the old motor driven clocks that use synchronous motors that will have an accuracy problem.

Properly generated line power keeps better long-term accuracy than a 32.768 crystal oscillator, which is the timebase of any 'quartz' wristwatch. Most of these are good for about a second a day systematic error, which the makers appear to run about that fast; this makes it easier to resynchronize the watch to a trusted time source, simply by pulling out the stem for a few seconds once in a while.

Complications arise with a line-frequcny clock when you have blackouts, of course; they're an inconvenience on the same order as your watch battery running out.

Nowadays, many clocks and some watches have Very Low Frequency receivers for NIST station WWVB, or equivalents in Europe and Asia. These timepieces are the ones touted as 'atomic.'

A few, but not many, clocks and appliances have an internal 32.768 KHz oscillator to back up their line frequency time base. A good combination, but not that common. The 'atomic' timebase is, I think, the more common type by now.

By the way---My most recent watch, a Seiko chronograph, comes amazingly close to zero. I believe it stays within about two seconds per month. Even after falling on it, smashing the crystal, and having it fixed.

Apropos of very little, here's a bit of trivia.

One of the inventors and early marketers of the electric clock was a man by the name of Laurens Hammond. He went on to become better known as the inventor of the electronic organ.

[Erasmus]

Just because crystals “can” regulate to within a second a year doesn’t mean every clock design goes to the expense of using such a crystal.

A crystal oscillator that can be counted on (heh-heh) to produce that kind of accuracy is orders of magnitude too expensive for consumer gear.

[loungitude]

I also cannot see how this would adversely affect home appliances.

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

Can you see how it would affect a multi-megawatt transformer or multi-thousand HP industrial motor? Mega-VAR power factor correction system? You know, something that has many, many lives depending on it?

[Nowhere Man]

Drifts in frequency across what is supposed to be a unified grid will also randomly pop circuit breakers and make emergency power routing (say in the event of storm damage) more difficult or impossible.

Well, if you get things out of phase, the generator will act as a motor and vice versa and when it keeps cycling out of control, you burn them out and get a huge mess. BTW, a Pittsburgh connection, Dr. Frank Conrad, who later started KDKA radio, developed the grid system and the switching needed back in 1905 for Westinghouse. He synchronized the grid and power generation to the Naval Time radio station the Navy had in Arlington much like some use WWV or WWVH today. I have the story on tape that Conrad's grandson told about it when KDKA celebrated it's 70th anniversary in 1990. I think he worked it together with Reginald Aubrey Fesseden, who was at the University of Pittsburgh at that time. Fesseden was the first to broadcast music and the human voice in good clarity in 1906.

I also remember my grandmother had an old Hoover vacuum that could run on anything from 25 to 60 cycle power, IIRC, I think it had an induction motor that can run at a constant speed no matter what cycle power your feed it. At that time, the 1930's, the West Coast, at least a good part of it ran at 50 cycles and Ontario Canada ran at 25 cycles, some industries up there still do. When you go that low, you can see the lights flicker plus for electronic stuff like radios and TV's, you need a much bigger transformer. I did talk to one guy who did manage to be able to run his TV on 16 cycle power once.

There is a hydro station in upstate New York that still puts out 40 cycles but has to be converted to 60. It has been in constant use since the mid 1890's. I hope the 19th Century craftsmen were very good, we need to keep the old stuff running since our "fearless leader Obongo" will not build any more coal plants.

[upchuck]

Despite what the article says, there’s no real reason given for this nor is there any estimate of how much money it may save. Alternate power methods (primarily windmills and solar) are notorious for producing dirty power. Maybe this has something to do with dumbing down the standard?

[Nowhere Man]

These kind of allowed fluctuations will kill industry in this country.

Unless they have their own onsite power generation, yes it will. I know my father worked at Shenango steel plant at Neville Island (near Pittsburgh) and they have their own power station, it was built in 1929 IIRC. You cannot shut the mill down at all, you got to keep it hot, if not, it is basically done for.

[fremont_steve]

I see you couldn’t “resist” trying to be punny.

[Erasmus]

Is this intended to be able to accommodate dirt-cheap solar power stations, windmills, and other corner-cutting power generator designs that can’t bother to look to a super-accurate standard like the cesium clock at WWV to keep cumulative cycle counts “going down the middle”?

Umm, no.

First of all there is not, nor will there ever be, any such thing as a "dirt-cheap solar power station," windmill, etc.

Second, no such power station needs to create its own time base, because when there's power on the grid, it already has one: the power on the grid. The phase of the power on the grid is determined by a super-stable time base, but there needs to be (and in fact must be) only one somewhere.

For various physical reasons, phase deviations on the grid from this master must be tolerated, but are not ignored. A grid power dispatch center tries to make up the lost phase, slowly, so that no net phase is lost over a period of a day or so. It does this by commanding key alternators to speed up slightly until the phase is made up. Of course, speeding up an alternator, although very slightly, tends to increase its voltage output, so the alternator controller correspondingly decreases its stator field so as to regulate its power contribution to the grid.

Other 'slave' alternators feed the grid under control of circuits that monitor the grid itself, in order to stay in phase and put the desired amount of power into it.

The new 'green' power sources of solar cells and windmills all generate DC, which is turned into AC by an 'inverter.' Inherent in this inverter design is control circuitry that regulates both the output voltage and phase so as to be appropriate to the grid during all times it is connected; essentially like the 'slave' alternators described above.

The inverter is essentially like the one you buy at the auto store, but scaled up a few orders of magnitude, and with much more sophisticated control circuits. There cannot be an inverter meant to feed the grid that does not have the ability to synchronize with it. The only solar or wind generator that might need a stable time base would be one that was the 'master' of a grid. If we're talking about power grids now in existence, this is not probable.

I grant some provisional plausibility to the idea that the grid may benefit from larger deviations from ideal phase; but I agree that it would be a poor idea to let this go uncorrected, contrary to present practice.

Some people on here are predicting doom, and inventing conspiracies, purely from the prospect of further deviations from ideal line frequency.

Bosch, I say ≤}B^)

[Erasmus]

Do you have the one with one or with two motors?

≤}B^)

[Doe Eyes]

Can you see how it would affect a multi-megawatt transformer or multi-thousand HP industrial motor? Mega-VAR power factor correction system? You know, something that has many, many lives depending on it?

No, please explain. Do you really think such a minor change in frequency would have such a dramatic affect? Please, post some numbers for me to consider.

[txhurl]

http://www.freerepublic.com/focus/f-news/2739718/posts

Power-grid experiment could confuse electric clocks

MSNBC ^ | June 24, 2011 | Seth Borenstein
WASHINGTON — A yearlong experiment with America’s electric grid could mess up traffic lights, security systems and some computers — and make plug-in clocks and appliances like programmable coffeemakers run up to 20 minutes fast. The group that oversees the U.S. power grid is proposing an experiment that would allow more frequency variation than it does now without corrections, according to a company presentation obtained by The Associated Press. Officials say they want to try this to make the power supply more reliable, save money and reduce what may be needless efforts. The test is tentatively set to start in...

[Erasmus]

Right, but with the grids sharing power between the plants on the grid and the rolling demands, what happens when one plant is more than 10 degrees out of phase with others on the grid?

There was a little cartoon on the small bulletin board by my advisor's door.

It was a little shack, not much more than an outhouse really. A sign on it read, "Dinkyville Power Company." There as a wire leading from an insulator on the wall up to a large power line. There was also smoke curling out of the window.

A speech ballon also emanated from that window. It said,

"I guess we shouldn't have tried to hook up to the grid 180 out."

Ever since the first AC grid, nobody could hook an alternator up to it without being very close in phase and in open circuit voltage,without hilarity ensuing. Think fractional degrees and fractional volts. Very early on, interlock circuits were applied to prevent it. Later, of course, automatic systems were developed with the same safeguards.

[Hunton Peck]

I can’t help it. It’s as if I’m trapped in the current.

[cynwoody]

My clocks pretty much all use WWVB now. And my computers synchronize to NTP servers. And of course my phone gets it from the carrier, which gets it from NTP or GPS.

I have an old electric that used to belong to my grandmother. It had a synchronous motor driving a gear train. However, it was a first generation synchronous motor: It had a gnarled knob on the back you needed to give a twist to to get it going. It kept great time (unless you twisted the knob the wrong way, in which case it kept great time in reverse).

The power companies kept the frequency very close to 60 hz. And if it deviated one way, they would run it deviated the other for a while to compensate. That meant the frequency over a long time period averaged extremely close to the nominal value. So, barring power failures and DST changes, you didn't need to touch an electric with a synchronous motor.

Properly generated line power keeps better long-term accuracy than a 32.768 crystal oscillator, which is the timebase of any 'quartz' wristwatch. Most of these are good for about a second a day systematic error, which the makers appear to run about that fast; this makes it easier to resynchronize the watch to a trusted time source, simply by pulling out the stem for a few seconds once in a while.

That's been my observation as well. The average electronic timepiece, be it an expensive computer (not using NTP) or a cheap Radio Shack stick-on, tends to gain between half a second and a second per day. For some reason, they usually seem to run fast, not slow.

The typical WWVB timepiece synchronizes once per day, in the wee hours of the morning when reception is likely to be best. During the day, it relies on its crystal control, which is no more accurate than typical. But at least the error gets corrected each day.

The better WWVB watches also synchronize only early in the morning. However, they note the degree of error accumulated while using the crystal and compensate for it (similar to what a good NTP client on a computer will do). The biggest source of error seems to be temeperature. So, as long as the watch experiences a uniform average ambient temperature, such compensation works well.

The better radio-controlled watches contain hardware / software that allows them to use European and Japanese time signals as well as WWVB.

By the way---My most recent watch, a Seiko chronograph, comes amazingly close to zero. I believe it stays within about two seconds per month. Even after falling on it, smashing the crystal, and having it fixed.

Does it use WWVB? Or does it have one of those premium, temperature-compensated crystal time bases?

[Pearls Before Swine]

Will abandonment of the 60 Hz standard affect ground loop hum?

No. It may change a few hundredths of a hertz from exactly 60.00 Hz, but it will be the same effect. The ground loops will still be there.

In fact, there may be no difference at all as far as anyone can tell. It looks like what will be abandoned is not 60 Hz power, but the requirement that the average frequency over long periods be held tightly to 60 Hz. In other words, the small fluctuations we now experience around 60 Hz may not be very different under the new system, except that they won't try real hard to "catch up" over a period of days or weeks.

A "why" this is a good idea would be appreciated!

[cynwoody]

I know earlier watches used a tuning fork oscillator to keep time.

The Bulova Accutron used a 360-hz tuning fork as its time base. It had a one-transistor circuit that kept the tuning fork humming by sending pulses to the electromagnets imbedded in the fork's tines.

Four million units were sold between 1960 and 1977.

[dljordan]

“Perhaps selling power strips that convert the varying AC to 60 hz, manufactured only by our good friends the Chinese.”

That’s one possibility. It’s a great moneymaker too. I install Chinese crap all day long, every day, and then I install it again, and again. Poor fit, poor workmanship, poor reliability, etc......

[editor-surveyor]

This is going to ‘cook’ the inverters on “grid tie” solar power sell-back systems, and it’ll do it quickly.

[meyer]

I just responded to a similar thread yesterday. That was an article by PMSNBC, and it wasn’t accurate. This one doesn’t appear to be accurate either.

Here’s what I wrote yesterday:

“”This is about as poorly-written an article as could be expected. Obviously, the journalist doesn’t have a grasp of the situation or the proposal at all.

The standards for operating frequency remain the same - normal operations are within 0.05 HZ of 60 HZ, and typically run from 59.98 to 60.02. It fluctuates during the course of the day as customers bring on loads and generators adjust output to compensate. If the generation output is higher than the load, the frequency will tend to rise as generators speed up. If the load requirement is higher than the generation, the frequency will tend to fall as generators slow down.

The requirements to operate within the same bandwidth remain the same. Automatic load shed requirements at very low frequencies still exist. Automatic Generation Control response characteristics remain the same. Reporting requirements for wide frequency excursions or sustained operation outside of normal limits (typically +/- 0.05 HZ) remain the same.

What is changing is the mandatory requirement to correct accumulated frequency error, AKA “time error”. Presently, when time error accumulates + or - 10 seconds, a time error correction is called. In time correction, the standard frequency is raised 0.02 Hz if the time is negative (slow) or lowered 0.02 Hz if the time error is positive (fast). This allows older synchronous clocks to remain at the correct time.

Fact is, there are very few older synchronous clocks around any more. And odds are, nobody would notice the 10 or 20 second error that had accumulated over time even if there were.””

[meyer]

Gonna hear a little more flutter, I suspect.

Wow!

Hadn't heard that term in a while! :-)