Re: [Emc-users] Seeking ideas how to sync an AC generator to 60 HZ average.
I like the idea of using the wood you want to burn as heat, there are many places around here that use the external boilers, small building built remote from houses or other heated structures by 20 to 100' or so, that then pipe the heated water to the buildings. I have seen them advertised in Mother Earth News. Then use PV for battery charging. If you put up LED lights (expensive currently, but use lots less electricity per lumen) especially the DC ones, you would be in good shape. Running dual electric lines around your house, one for DC only (use extra sized wire for DC to keep the resistance losses down), and a separate set for AC that could all go back to an inverter or small motor generator set for when it is needed. If I had it to do over myself, and expense was no object :) ... I would do 48VDC, charge with solar, have an 'automatic generator' setup like Xantrex that Yann talked about. Probably set up the generator to kick in if the batteries got to low or the AC needed was over what an inverter could use. But first, it would need to go into a new house/workshop that was thermally efficient (something I don't have now). If I had the wood Erik has, the outside boiler or making some 'rocket stoves' (efficent heating type stoves, not really for cooking) would be great to heat with. Dreams are good. ><> ... Jack Whatever you do, work at it with all your heart... Colossians 3:23 -- Increase Visibility of Your 3D Game App & Earn a Chance To Win $500! Tap into the largest installed PC base & get more eyes on your game by optimizing for Intel(R) Graphics Technology. Get started today with the Intel(R) Software Partner Program. Five $500 cash prizes are up for grabs. http://p.sf.net/sfu/intelisp-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Seeking ideas how to sync an AC generator to 60 HZ average.
Le 30/11/2010 13:37, Erik Christiansen a écrit : > If we still lived out there the whole time, I'd do much of that. (And > get new deep cycle batteries for the 24v [1] inverter.) But we lost > between 600 and 700 large trees in the storms in 2006. That's several > thousand tonnes of hardwood, which will rot away in 50 years or so. > Burning fossil fuel in the petrol generator isn't as appealing as a > steam engine fooshing away quietly, with some boiler management > electronics, and an automatic stoker. (It's just that boilers are a bit > dangerous, unless you go for a monotube.) > > I work in a company that makes electrification system for houses that are away from grid. In my opinion, photovoltaics panels + deep cycles batteries are the better way to insure a reliable power source. But with such a system, if you don't want it to cost you too much, you'll get limited energy ressource. Enough for the light and the basical home usage. Don't even expect to warm your water with it, for instance. So if you need sometimes large power amount, having a diesel generator coupled to you inverter is a ood idea. If you use a smart enough inverter, like one you can get from Xantrex, it can be programmed to automatically start generator when the required AC current go over a limit. This will preserve batteries. You can also do not use photovoltaics panels at all, and only use the generator to charge the batterie every 2 or 3 days, but in y opinion this is not a good solution. PV panel never give up, mecanical machine such a generator engine does. So having just enough pv panels to insure the basical energy production is a good idea. Regarding the generator, if full automatisation is not required, and considering you have a fairly amount of wood available, you can look for making a wood gas generator and run a old gasoline generator with it. I think this is really simpler thant steam engine, and really safer. With a lower efficiency anyway, but if you have lot of wood this will not be a problem. With some clever thinking, I think it is also possible to automatise the wood gas generator. For example starting the fire with a electrical hot air generator, like they do in pellets stoves. The you may have to make some automated system to feed wood in the burner, and you should be done. http://en.wikipedia.org/wiki/Wood_gas_generator http://fr.wikipedia.org/wiki/Gazog%C3%A8ne -- Increase Visibility of Your 3D Game App & Earn a Chance To Win $500! Tap into the largest installed PC base & get more eyes on your game by optimizing for Intel(R) Graphics Technology. Get started today with the Intel(R) Software Partner Program. Five $500 cash prizes are up for grabs. http://p.sf.net/sfu/intelisp-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Seeking ideas how to sync an AC generator to 60 HZ average.
On Tue, Nov 30, 2010 at 7:37 AM, Erik Christiansen wrote: > On Wed, Nov 24, 2010 at 11:29:23AM -0600, Jon Elson wrote: > > > > > Yes, but if you are 20 miles from the grid, and the only person out > > there who wants to hook up, the power company will usually charge you > > a HUGE fee, well over $10K to bring out the lines. If you are really > > lucky, they might be planning on bringing power out your way, so you > > should always ask, but the answer may not be pleasing. > > When we last asked, about 20 years ago, it was about $60k to connect out > on the farm, and about 20 acres of forest would have to be bulldozed for > the line. Prices aren't likely to have fallen much, and now we have to > plant 10 trees for every one we 'doze. > > > I agree, running a Diesel generator 24/7 is totally insane, and the > > off-grid home power people have all sorts of solutions for this. > > Yeah. There's plenty to do outside, so who needs power until dark? > With the help of a full-sized gas refrigerator, that works for us. > In the evening we arc up the genny. > > > For low-power appliances like digital alarm clocks, they have 12 V DC > > versions with crystal oscillators for RV use, and LED lighting would > > be the best thing to get, and run off 12 V power, too. You could run > > the rest of the place off batteries and an inverter, and fire up the > > generator once a day to charge the batteries. Get solar panels to > > charge the batteries for days when the machine shop is not being used. > > Get a Beagle Board and car-type LCD screen for you general purpose > > computer, the Beagle only draws 3 W and the 12 V LCDs take maybe 8 W > > when the backlight is on. The Beagle can't run EMC2 just yet, but > > eventually there will be a real time package for it. > > If we still lived out there the whole time, I'd do much of that. (And > get new deep cycle batteries for the 24v [1] inverter.) But we lost > between 600 and 700 large trees in the storms in 2006. That's several > thousand tonnes of hardwood, which will rot away in 50 years or so. > Burning fossil fuel in the petrol generator isn't as appealing as a > steam engine fooshing away quietly, with some boiler management > electronics, and an automatic stoker. (It's just that boilers are a bit > dangerous, unless you go for a monotube.) > > Erik > > [1] A 48v sinewave inverter would be better, but expensive. >(Even at 24v, the DC draw is hefty when you pull a few amps of 240v) > > > -- > Increase Visibility of Your 3D Game App & Earn a Chance To Win $500! > Tap into the largest installed PC base & get more eyes on your game by > optimizing for Intel(R) Graphics Technology. Get started today with the > Intel(R) Software Partner Program. Five $500 cash prizes are up for grabs. > http://p.sf.net/sfu/intelisp-dev2dev > ___ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users > Hi to All who responded or were interested: It will totally amazing at the number of structures that will be off the grid over the next decade. More to come next year. Thanks Don -- Increase Visibility of Your 3D Game App & Earn a Chance To Win $500! Tap into the largest installed PC base & get more eyes on your game by optimizing for Intel(R) Graphics Technology. Get started today with the Intel(R) Software Partner Program. Five $500 cash prizes are up for grabs. http://p.sf.net/sfu/intelisp-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Seeking ideas how to sync an AC generator to 60 HZ average.
On Wed, Nov 24, 2010 at 11:29:23AM -0600, Jon Elson wrote: > > > Yes, but if you are 20 miles from the grid, and the only person out > there who wants to hook up, the power company will usually charge you > a HUGE fee, well over $10K to bring out the lines. If you are really > lucky, they might be planning on bringing power out your way, so you > should always ask, but the answer may not be pleasing. When we last asked, about 20 years ago, it was about $60k to connect out on the farm, and about 20 acres of forest would have to be bulldozed for the line. Prices aren't likely to have fallen much, and now we have to plant 10 trees for every one we 'doze. > I agree, running a Diesel generator 24/7 is totally insane, and the > off-grid home power people have all sorts of solutions for this. Yeah. There's plenty to do outside, so who needs power until dark? With the help of a full-sized gas refrigerator, that works for us. In the evening we arc up the genny. > For low-power appliances like digital alarm clocks, they have 12 V DC > versions with crystal oscillators for RV use, and LED lighting would > be the best thing to get, and run off 12 V power, too. You could run > the rest of the place off batteries and an inverter, and fire up the > generator once a day to charge the batteries. Get solar panels to > charge the batteries for days when the machine shop is not being used. > Get a Beagle Board and car-type LCD screen for you general purpose > computer, the Beagle only draws 3 W and the 12 V LCDs take maybe 8 W > when the backlight is on. The Beagle can't run EMC2 just yet, but > eventually there will be a real time package for it. If we still lived out there the whole time, I'd do much of that. (And get new deep cycle batteries for the 24v [1] inverter.) But we lost between 600 and 700 large trees in the storms in 2006. That's several thousand tonnes of hardwood, which will rot away in 50 years or so. Burning fossil fuel in the petrol generator isn't as appealing as a steam engine fooshing away quietly, with some boiler management electronics, and an automatic stoker. (It's just that boilers are a bit dangerous, unless you go for a monotube.) Erik [1] A 48v sinewave inverter would be better, but expensive. (Even at 24v, the DC draw is hefty when you pull a few amps of 240v) -- Increase Visibility of Your 3D Game App & Earn a Chance To Win $500! Tap into the largest installed PC base & get more eyes on your game by optimizing for Intel(R) Graphics Technology. Get started today with the Intel(R) Software Partner Program. Five $500 cash prizes are up for grabs. http://p.sf.net/sfu/intelisp-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Seeking ideas how to sync an AC generator to 60 HZ average.
I have researched this subject over the last 10+ years. And I know a couple people that have tried limited phases of this experiment as well. My conclusion is, if do not have enough hobbies and too much free time, adding 'home shop power station' to the list might be fun. But there is no savings to be had over grid power. Even if you use the waste heat from the generator in winter, plan on being much less efficient in your work or shop activities, as your generating system will demand time and attention. I have a waste oil heater in the shop, been here for 10 years. I finally got tired of all the time it wastes (waste oil is NOT free heat) and am installing a gas furnace in it's place. Back to your regularly scheduled programming. dk -- Increase Visibility of Your 3D Game App & Earn a Chance To Win $500! Tap into the largest installed PC base & get more eyes on your game by optimizing for Intel(R) Graphics Technology. Get started today with the Intel(R) Software Partner Program. Five $500 cash prizes are up for grabs. http://p.sf.net/sfu/intelisp-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Seeking ideas how to sync an AC generator to 60 HZ average.
Hello gentlemen, I have another solution for the power supply problem: move to Europe! In our village (270 some people) we have two transformer stations on a grid-connected 20 kV three-phase line. The power lines go to (or come from) three neighboring villages and eventually end up at the region's 110 kV-transformer station about 20 km away. Our house has a 400V, 50 A, 3-phase supply as all the houses do, this is average. All the cabling is under the roads under ground, in our street a PVC cable 3x75 mm sq. + 50 mm sq.for the middle conductor (implicit ground). This is standard für all single houses, a corresponding bit more for larger ones. I have experienced one or two power failures since we live here (32 years). In a larger city like Munich, for instance, 50 km from us, power failures are completely unknown. I have experienced one when I was a little boy. Sometimes we have short power drops when lighning hit the power line, but only for a few sine periods, so most PC's and other appliances don't even recognize it. America should improve their energy supply! By the way: I have learned electricity, house wiring and TV repair at high school in Michigan some 45 years ago and know what the difference ist! Peter Blodow Przemek Klosowski schrieb: > On Wed, Nov 24, 2010 at 1:11 PM, Jim Fleig wrote: > >> Hello All, >> >> Happy Thanksgiving one day early! >> >> To protect sensitive electronics in machine tool controls (and many >> other places) put an UPS (Uninterruptible Power Supply) between the >> power source and the sensitive electronics. Most DC power supplies >> are converting 110 VAC to whatever DC voltages are needed. The UPS >> unit is easy to put into the circuit and for most machine tool >> controls will cost about $150.00. >> > > Absolutely, but the price goes up tremendously with power. I am now > pricing an 80kW system and it seems to be 70k$ (about half of it is > the batteries for 30 min uptime so some of the price could be cut). > Come to think about it, the rule of thumb seems to be 1k$ per 1kW > > I suppose a CNC system could use a simple power conditioner for the > power feed to the motors and the UPS for the electronics/controller, > but that does not guarantee against power surge getting into the power > stage and flowing back into the controls. > > -- > Increase Visibility of Your 3D Game App & Earn a Chance To Win $500! > Tap into the largest installed PC base & get more eyes on your game by > optimizing for Intel(R) Graphics Technology. Get started today with the > Intel(R) Software Partner Program. Five $500 cash prizes are up for grabs. > http://p.sf.net/sfu/intelisp-dev2dev > ___ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users > > -- Increase Visibility of Your 3D Game App & Earn a Chance To Win $500! Tap into the largest installed PC base & get more eyes on your game by optimizing for Intel(R) Graphics Technology. Get started today with the Intel(R) Software Partner Program. Five $500 cash prizes are up for grabs. http://p.sf.net/sfu/intelisp-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Seeking ideas how to sync an AC generator to 60 HZ average.
On Wed, Nov 24, 2010 at 1:11 PM, Jim Fleig wrote: > Hello All, > > Happy Thanksgiving one day early! > > To protect sensitive electronics in machine tool controls (and many > other places) put an UPS (Uninterruptible Power Supply) between the > power source and the sensitive electronics. Most DC power supplies > are converting 110 VAC to whatever DC voltages are needed. The UPS > unit is easy to put into the circuit and for most machine tool > controls will cost about $150.00. Absolutely, but the price goes up tremendously with power. I am now pricing an 80kW system and it seems to be 70k$ (about half of it is the batteries for 30 min uptime so some of the price could be cut). Come to think about it, the rule of thumb seems to be 1k$ per 1kW I suppose a CNC system could use a simple power conditioner for the power feed to the motors and the UPS for the electronics/controller, but that does not guarantee against power surge getting into the power stage and flowing back into the controls. -- Increase Visibility of Your 3D Game App & Earn a Chance To Win $500! Tap into the largest installed PC base & get more eyes on your game by optimizing for Intel(R) Graphics Technology. Get started today with the Intel(R) Software Partner Program. Five $500 cash prizes are up for grabs. http://p.sf.net/sfu/intelisp-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Seeking ideas how to sync an AC generator to 60 HZ average.
Hello All, Happy Thanksgiving one day early! To protect sensitive electronics in machine tool controls (and many other places) put an UPS (Uninterruptible Power Supply) between the power source and the sensitive electronics. Most DC power supplies are converting 110 VAC to whatever DC voltages are needed. The UPS unit is easy to put into the circuit and for most machine tool controls will cost about $150.00. A higher joule rating provides better protection. Problem power, toasted UPS unit, $150.00 replacement expense purchasing the item at the local big box computer store and the system is up and running again. Relatively inexpensive and quick recovery. Have a good day, Jim Fleig CNC Services 585 975-9618 On Nov 24, 2010, at 12:47 PM, Stuart Stevenson wrote: > Gentlemen, > Having researched the subject of isolating from the grid to try to > convert > my shop I will interject a comment or two. > The KWH cost of utility power is amazingly cheap compared to > generating it > locally. > The KWH cost is not the only cost. At least once a year we > experience a > power glitch of the form necessary to harm sensitive electronics > (and at > times other things connected to the power lines). > We have ground devices to attempt to shield our machine controls. > These > shield devices do not always work. I do not know how much the added > cost > truly is but the aggravation is tremendous. When you see the lights > flicker > bright or dim you cringe. If a machine stops you do not know if it > will > restart. Many times one of the machines will not restart. The remedy > for > restart is usually a board replacement. The board is not cheap. The > downtime > is not cheap. How do you quantify it? > How do you know if the next board you replace was not damaged by > the same > event that killed the previous board? We have replaced all four > boards in > each of three machines in a year. This replacement came after a > particularly > damaging power fluctuation. > I would definitely like to be isolated from the grid. > thanks > Stuart > > -- > dos centavos > --- > --- > --- > - > Increase Visibility of Your 3D Game App & Earn a Chance To Win $500! > Tap into the largest installed PC base & get more eyes on your game by > optimizing for Intel(R) Graphics Technology. Get started today with > the > Intel(R) Software Partner Program. Five $500 cash prizes are up for > grabs. > http://p.sf.net/sfu/intelisp-dev2dev > ___ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users -- Increase Visibility of Your 3D Game App & Earn a Chance To Win $500! Tap into the largest installed PC base & get more eyes on your game by optimizing for Intel(R) Graphics Technology. Get started today with the Intel(R) Software Partner Program. Five $500 cash prizes are up for grabs. http://p.sf.net/sfu/intelisp-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Seeking ideas how to sync an AC generator to 60 HZ average.
Gentlemen, Having researched the subject of isolating from the grid to try to convert my shop I will interject a comment or two. The KWH cost of utility power is amazingly cheap compared to generating it locally. The KWH cost is not the only cost. At least once a year we experience a power glitch of the form necessary to harm sensitive electronics (and at times other things connected to the power lines). We have ground devices to attempt to shield our machine controls. These shield devices do not always work. I do not know how much the added cost truly is but the aggravation is tremendous. When you see the lights flicker bright or dim you cringe. If a machine stops you do not know if it will restart. Many times one of the machines will not restart. The remedy for restart is usually a board replacement. The board is not cheap. The downtime is not cheap. How do you quantify it? How do you know if the next board you replace was not damaged by the same event that killed the previous board? We have replaced all four boards in each of three machines in a year. This replacement came after a particularly damaging power fluctuation. I would definitely like to be isolated from the grid. thanks Stuart -- dos centavos -- Increase Visibility of Your 3D Game App & Earn a Chance To Win $500! Tap into the largest installed PC base & get more eyes on your game by optimizing for Intel(R) Graphics Technology. Get started today with the Intel(R) Software Partner Program. Five $500 cash prizes are up for grabs. http://p.sf.net/sfu/intelisp-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Seeking ideas how to sync an AC generator to 60 HZ average.
dave wrote: > Hi Jack, > > Have you computed the real costs of running a diesel powered genset for > local power. It comes out to be not very attractive. > Just the cost of the fuel alone is more per KWH than the grid. > Yes, but if you are 20 miles from the grid, and the only person out there who wants to hook up, the power company will usually charge you a HUGE fee, well over $10K to bring out the lines. If you are really lucky, they might be planning on bringing power out your way, so you should always ask, but the answer may not be pleasing. I agree, running a Diesel generator 24/7 is totally insane, and the off-grid home power people have all sorts of solutions for this. For low-power appliances like digital alarm clocks, they have 12 V DC versions with crystal oscillators for RV use, and LED lighting would be the best thing to get, and run off 12 V power, too. You could run the rest of the place off batteries and an inverter, and fire up the generator once a day to charge the batteries. Get solar panels to charge the batteries for days when the machine shop is not being used. Get a Beagle Board and car-type LCD screen for you general purpose computer, the Beagle only draws 3 W and the 12 V LCDs take maybe 8 W when the backlight is on. The Beagle can't run EMC2 just yet, but eventually there will be a real time package for it. Jon -- Increase Visibility of Your 3D Game App & Earn a Chance To Win $500! Tap into the largest installed PC base & get more eyes on your game by optimizing for Intel(R) Graphics Technology. Get started today with the Intel(R) Software Partner Program. Five $500 cash prizes are up for grabs. http://p.sf.net/sfu/intelisp-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Seeking ideas how to sync an AC generator to 60 HZ average.
Hi Jack, Have you computed the real costs of running a diesel powered genset for local power. It comes out to be not very attractive. Just the cost of the fuel alone is more per KWH than the grid. Just my tuppence. Dave On Tue, 2010-11-23 at 12:37 -0600, Jack Coats wrote: > Keeping exactly 60Hz isn't that critical. The real timing is being done by > crystals > and the clock can be set using a little GPS or even easier NTP software if > you have > reasonable internet access. > > Are you considering staying in sync if commercial power fails? > > For computer loads UPSes are great, but their frequency does drift a little. > For > industrial applications (like EMC2 :) even if it is 'home industry' ) exact > timing > doesn't matter, unless you are planning on 'grid tie' your shop to the grid. > Then > you should look into the 'grid tie' hardware that the solar and wind folks > use. > They have been doing it for a long time now (10+ years) and have it down. > > Personally I would like to have a 'off the grid' shop. Solar for lights and > light work, > kick in a generator when 'real power' is needed, and as an optional battery > recharger. > > I guess it is just the little bit of 'green geek' in me that wants that. > But since I don't > have a 'shop' I can dream. Practicality says that building it and tie it to > the grid and > just pay the bills makes the most economic sense in the short to mid-term (2 > to 10 years) > to me. > -- > Increase Visibility of Your 3D Game App & Earn a Chance To Win $500! > Tap into the largest installed PC base & get more eyes on your game by > optimizing for Intel(R) Graphics Technology. Get started today with the > Intel(R) Software Partner Program. Five $500 cash prizes are up for grabs. > http://p.sf.net/sfu/intelisp-dev2dev > ___ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users -- Increase Visibility of Your 3D Game App & Earn a Chance To Win $500! Tap into the largest installed PC base & get more eyes on your game by optimizing for Intel(R) Graphics Technology. Get started today with the Intel(R) Software Partner Program. Five $500 cash prizes are up for grabs. http://p.sf.net/sfu/intelisp-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Seeking ideas how to sync an AC generator to 60 HZ average.
Typical losses in high voltage transmission lines are on the order of 6 to 7% distributed between corona and IR losses depending on the voltage. D On Tue, 2010-11-23 at 18:10 +, Andy Pugh wrote: > On 23 November 2010 16:52, Dave wrote: > > > Apparently there is a large DC inverter station out in the northwest?? > > that is used to allow different synchronization of the grids in the > > eastern US with the western US or across some other regional divide. > > I think that might be to prevent the US grid being a rather efficient > antenna and radiating half the energy into space. > > 60Hz x speed of light = 3000 miles. > -- Increase Visibility of Your 3D Game App & Earn a Chance To Win $500! Tap into the largest installed PC base & get more eyes on your game by optimizing for Intel(R) Graphics Technology. Get started today with the Intel(R) Software Partner Program. Five $500 cash prizes are up for grabs. http://p.sf.net/sfu/intelisp-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Seeking ideas how to sync an AC generator to 60 HZ average.
Google "HVDC in the pacific northwest" will get you a couple of links. There are two links (npi) from near The Dalles dam on the Columbia to S CA. Also there is a site that lays out DC interties as firewalls between major grids therefore minimizing intergrid interferences leading to instability. I expected to find something on the line that runs across WA and crosses Hyw 18 near Covington (major substation) but have come up blank. The geometry is that of a HVDC line ... three conductors in a triangle maybe a foot or so on a side. Nice pictures in a pdf on HVDC in Alberta. Dave On Tue, 2010-11-23 at 11:52 -0500, Dave wrote: > Interesting. > > Apparently there is a large DC inverter station out in the northwest?? > that is used to allow different synchronization of the grids in the > eastern US with the western US or across some other regional divide. > > Sort of like a giant AC drive taken to an entirely different level.. ;-) > > I remember finding it via a google lookup one time. > > Dave > > On 11/23/2010 11:25 AM, dave wrote: > > 50 some years ago a couple of engineers came to Coulee from the Denver > > office (USBR) and installed a mag amp in feed forward mode to control > > the penstock gate on one of the small units. This was before the third > > powerhouse so the units were all 108 Mw. This one unit was used to swing > > the entire Northwest Power Pool ( OR, WA, ID, UT, and most of MT and > > WY ). I don't have any quantitative figures but the frequency regulation > > got 10X better. > > > > Dave > > > > On Tue, 2010-11-23 at 17:17 +0200, Roland Jollivet wrote: > > > >> I heard once (here in SA) that the mains cycles were adjusted close to > >> midnight, so that the number remained consistent on a daily basis. I don't > >> know how it's arranged though, since there are so many power stations to > >> sync. > >> > >> Regards > >> Roland > >> > >> > >> > >> > >> On 23 November 2010 16:49, Ian W. Wright wrote: > >> > >> > >>> On 23/11/2010 14:37, Andy Pugh wrote: > >>> > On 23 November 2010 14:31, Ian W. Wright > > >>> wrote: > >>> > > > hell, I've seen our mains frequency > > vary from 47 to 54 Hz over the day many times depending on > > the load and no one ever complains... > > > Though supposedly you should still always get 432 cycles per day. > > > >>> Yes, you're right but I'm not sure how close they ahere to > >>> that nowadays. With the common frequency dips due to load > >>> problems and the tendency for people to convert to quartz > >>> timing instead of mains synchronous, I wonder if they bother > >>> so much or whether they just try to get it right weekly or > >>> some such. Maybe I'll put a mains frequency monitor on here > >>> out of interest - its 13 years since I retired from the > >>> ratrace of chasing power around plant rooms.. > >>> > >>> Ian > >>> > >>> > >>> -- > >>> Increase Visibility of Your 3D Game App& Earn a Chance To Win $500! > >>> Tap into the largest installed PC base& get more eyes on your game by > >>> optimizing for Intel(R) Graphics Technology. Get started today with the > >>> Intel(R) Software Partner Program. Five $500 cash prizes are up for grabs. > >>> http://p.sf.net/sfu/intelisp-dev2dev > >>> ___ > >>> Emc-users mailing list > >>> Emc-users@lists.sourceforge.net > >>> https://lists.sourceforge.net/lists/listinfo/emc-users > >>> > >>> > >> -- > >> Increase Visibility of Your 3D Game App& Earn a Chance To Win $500! > >> Tap into the largest installed PC base& get more eyes on your game by > >> optimizing for Intel(R) Graphics Technology. Get started today with the > >> Intel(R) Software Partner Program. Five $500 cash prizes are up for grabs. > >> http://p.sf.net/sfu/intelisp-dev2dev > >> ___ > >> Emc-users mailing list > >> Emc-users@lists.sourceforge.net > >> https://lists.sourceforge.net/lists/listinfo/emc-users > >> > > > > -- > > Increase Visibility of Your 3D Game App& Earn a Chance To Win $500! > > Tap into the largest installed PC base& get more eyes on your game by > > optimizing for Intel(R) Graphics Technology. Get started today with the > > Intel(R) Software Partner Program. Five $500 cash prizes are up for grabs. > > http://p.sf.net/sfu/intelisp-dev2dev > > ___ > > Emc-users mailing list > > Emc-users@lists.sourceforge.net > > https://lists.sourceforge.net/lists/listinfo/emc-users > > > > > > > -- > Increase Visibility of Your 3D Game App & Earn a Chance
Re: [Emc-users] Seeking ideas how to sync an AC generator to 60 HZ average.
I think the satellites have caesium clocks now but that is only from memory. The reason they need to be adjusted fairly frequently is due to the satellites propensity to fall back to earth - i.e. their orbits decay over time making the satellites closer to earth and hence the signal travel time less. They 'correct' the clock on the satellite for so many weeks / months and then boost the satellite back up into its original orbit and start again. They do it this way because of the high cost of boosting the satellite back up and the limited fuel on board. Ian __ Ian W. Wright Sheffield UK On 24/11/2010 02:27, Jon Elson wrote: > Przemek Klosowski wrote: >> On Tue, Nov 23, 2010 at 1:14 PM, Jon Elson wrote: >> >> >>> The GPS system has atomic clocks accurate to some insane level like one >>> second in 10,000 years. They have to periodically adjust the clocks for >>> relativistic >>> effects. >>> >> NIST runs the master clocks for the system from Boulder, and keeps >> improving them. The most recent generation uses single Aluminum ion, >> and is accurate to 1s in over 3 billion years. > Right, and the clocks on board the GPS satellites are periodically reset > from the NIST master > clocks. The time standards carried on board the satellites are not this > accurate, but are still > Rubidium atomic clocks, and WAYYY more accurate than anything us mere > mortals can > afford. At least, that is the way the system used to be set up, there > might have been updates > since. > > Jon > > -- > Increase Visibility of Your 3D Game App& Earn a Chance To Win $500! > Tap into the largest installed PC base& get more eyes on your game by > optimizing for Intel(R) Graphics Technology. Get started today with the > Intel(R) Software Partner Program. Five $500 cash prizes are up for grabs. > http://p.sf.net/sfu/intelisp-dev2dev > ___ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users > > > - > No virus found in this message. > Checked by AVG - www.avg.com > Version: 10.0.1153 / Virus Database: 424/3274 - Release Date: 11/23/10 > > -- Increase Visibility of Your 3D Game App & Earn a Chance To Win $500! Tap into the largest installed PC base & get more eyes on your game by optimizing for Intel(R) Graphics Technology. Get started today with the Intel(R) Software Partner Program. Five $500 cash prizes are up for grabs. http://p.sf.net/sfu/intelisp-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Seeking ideas how to sync an AC generator to 60 HZ average.
Thanks John and All; It appears NTP solves the clock drift problem in Linux systems, completely. As soon as I can ferret out the HAL bits and pieces needed to keep the generator synced to the PC clock, this problem is solved. Any clues of the bits and pieces needed would give me a great jump start. Sincere Thanks Don On Tue, Nov 23, 2010 at 12:17 AM, John Kasunich wrote: > Do you have internet access at the site? > > If you are running an PC for EMC, you can use NTP to keep > the PC's clock synced to the rest of the world, and some HAL > bits and pieces to keep the generator synced to the PC > clock. EMC's encoder component could easily count 60Hz. > > > On Tue, 23 Nov 2010 00:11 -0500, "Don Stanley" > wrote: > > Hi All; > > My next project is a remote off grid 60 HZ power unit. > > I am thinking of a EMC2 PID to control the RPM. > > I am also expecting maybe a 1-2 HZ momentary shift as the > > big power loads come on and off line. > > > > I am looking for a method to get a reliable reference that can be used to > > average 60 HZ through the power surges and correct a local timer drift > > for long term accuracy. A simple WWV corrected timer > > (a Wall mart Atomic clock with outputs). > > Anyone know of such a device? > > > > Thanks > > Don > > > -- > > Increase Visibility of Your 3D Game App & Earn a Chance To Win $500! > > Tap into the largest installed PC base & get more eyes on your game by > > optimizing for Intel(R) Graphics Technology. Get started today with the > > Intel(R) Software Partner Program. Five $500 cash prizes are up for > > grabs. > > http://p.sf.net/sfu/intelisp-dev2dev > > ___ > > Emc-users mailing list > > Emc-users@lists.sourceforge.net > > https://lists.sourceforge.net/lists/listinfo/emc-users > > > -- > John Kasunich > jmkasun...@fastmail.fm > > > > -- > Increase Visibility of Your 3D Game App & Earn a Chance To Win $500! > Tap into the largest installed PC base & get more eyes on your game by > optimizing for Intel(R) Graphics Technology. Get started today with the > Intel(R) Software Partner Program. Five $500 cash prizes are up for grabs. > http://p.sf.net/sfu/intelisp-dev2dev > ___ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users > -- Increase Visibility of Your 3D Game App & Earn a Chance To Win $500! Tap into the largest installed PC base & get more eyes on your game by optimizing for Intel(R) Graphics Technology. Get started today with the Intel(R) Software Partner Program. Five $500 cash prizes are up for grabs. http://p.sf.net/sfu/intelisp-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Seeking ideas how to sync an AC generator to 60 HZ average.
Przemek Klosowski wrote: > On Tue, Nov 23, 2010 at 1:14 PM, Jon Elson wrote: > > >> The GPS system has atomic clocks accurate to some insane level like one >> second in 10,000 years. They have to periodically adjust the clocks for >> relativistic >> effects. >> > > NIST runs the master clocks for the system from Boulder, and keeps > improving them. The most recent generation uses single Aluminum ion, > and is accurate to 1s in over 3 billion years. Right, and the clocks on board the GPS satellites are periodically reset from the NIST master clocks. The time standards carried on board the satellites are not this accurate, but are still Rubidium atomic clocks, and WAYYY more accurate than anything us mere mortals can afford. At least, that is the way the system used to be set up, there might have been updates since. Jon -- Increase Visibility of Your 3D Game App & Earn a Chance To Win $500! Tap into the largest installed PC base & get more eyes on your game by optimizing for Intel(R) Graphics Technology. Get started today with the Intel(R) Software Partner Program. Five $500 cash prizes are up for grabs. http://p.sf.net/sfu/intelisp-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Seeking ideas how to sync an AC generator to 60 HZ average.
Edward Bernard wrote: > Does this mean the "smart grid" we have heard so much about is just a pipe > dream? > Smart grid has absolutely nothing to do with stability of large electrical grid systems. Smart grid is mostly related to having individual appliances able to be turned off at peak load times, and giving customers a credit for doing that. There is some worry, I think, about all the non-linear loads that draw constant power over a range of voltages. In cases of extreme shortage of generating capacity, they used to do "brownouts" where they would reduce voltage, and incandescent and heating loads would be reduced. Compact fluorescents, motors on VFDs, computers, etc. all will draw constant power during a brownout, and they look a lot less resistive also, so may be less absorptive to network instability (less damping). Jon -- Increase Visibility of Your 3D Game App & Earn a Chance To Win $500! Tap into the largest installed PC base & get more eyes on your game by optimizing for Intel(R) Graphics Technology. Get started today with the Intel(R) Software Partner Program. Five $500 cash prizes are up for grabs. http://p.sf.net/sfu/intelisp-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Seeking ideas how to sync an AC generator to 60 HZ average.
Jack Coats wrote: > In the old days I worked on IBM mainframes, and a small mainframe (4341 if I > remember right) had a generator > set to help isolate the power. A crazy friend of mine bought a pair of 370-145 "mainframes" that were retired at our work. We tore one apart for parts, and actually tried to get the other one working. They had a 17 KVA motor generator set in the back, that converted 208 3 phase 60 Hz power to 115 V 3 phase 415 Hz power. I guess that means a 2-pole induction motor turning a 14-pole alternator at about 3560 RPM. Unfortunately, his small house had only a 60 A 240 V service, and we were never able to get the motor up to delta connection without tripping his main breaker. So, important digital loads on the machine ran off the MG set, but the cooling fans, floppy drive motor and front panel lights ran off the 60 Hz power. The power supplies were quite small for linear supplies. They had 3-phase transformer-rectifiers, and then a thing they called an electronic capacitor. During the line peaks they shunted current through a big inductor, then turned this off during the dips between cycles. This allowed them to use a TINY capacitor for a pretty hefty supply, like 5 V at 300 A. The 370/145 was an insanely primitive minicomputer running an amazingly "vertical" microcode emulation of the 370 instruction set, and the performance showed it. They ran VM/370 and a bunch of MVS and TSO systems under it. It generally took them 45 minutes to an hour to bring all these OSes back up after a crash. TOTAL insanity. Jon -- Increase Visibility of Your 3D Game App & Earn a Chance To Win $500! Tap into the largest installed PC base & get more eyes on your game by optimizing for Intel(R) Graphics Technology. Get started today with the Intel(R) Software Partner Program. Five $500 cash prizes are up for grabs. http://p.sf.net/sfu/intelisp-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Seeking ideas how to sync an AC generator to 60 HZ average.
On Tue, Nov 23, 2010 at 1:14 PM, Jon Elson wrote: > The GPS system has atomic clocks accurate to some insane level like one > second in 10,000 years. They have to periodically adjust the clocks for > relativistic > effects. NIST runs the master clocks for the system from Boulder, and keeps improving them. The most recent generation uses single Aluminum ion, and is accurate to 1s in over 3 billion years. This is so sensitive that when the latest clock was being tested it showed a discrepancy which at first got everyone worried, but then turned out to be the result of a 17 cm elevation difference between it and the previous clock used for reference. The clock instrument scientists wrote a nice Science paper on general relativistic effects of Earth gravitational field: http://www.sciencemag.org/content/329/5999/1630.abstract http://tf.boulder.nist.gov/general/pdf/2447.pdf -- Increase Visibility of Your 3D Game App & Earn a Chance To Win $500! Tap into the largest installed PC base & get more eyes on your game by optimizing for Intel(R) Graphics Technology. Get started today with the Intel(R) Software Partner Program. Five $500 cash prizes are up for grabs. http://p.sf.net/sfu/intelisp-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Seeking ideas how to sync an AC generator to 60 HZ average.
- Original Message From: Jon Elson To: Enhanced Machine Controller (EMC) Sent: Tue, November 23, 2010 12:24:47 PM Subject: Re: [Emc-users] Seeking ideas how to sync an AC generator to 60 HZ average. Experts have tried to model the whole grid, and found it to be very nearly mathematically intractable. Resistance and leakage inductance in transformers, etc. are the only thing keeping the grid (barely) stable. Jon Does this mean the "smart grid" we have heard so much about is just a pipe dream? -- Increase Visibility of Your 3D Game App & Earn a Chance To Win $500! Tap into the largest installed PC base & get more eyes on your game by optimizing for Intel(R) Graphics Technology. Get started today with the Intel(R) Software Partner Program. Five $500 cash prizes are up for grabs. http://p.sf.net/sfu/intelisp-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Seeking ideas how to sync an AC generator to 60 HZ average.
Sounds just like the data centre I ran the services for - except that we used ICL mainframes yuk!! Ian On 23/11/2010 18:55, Jack Coats wrote: > I helped build a 'small data center', we put in 3 1MW diesel generators to > feed two 1MW APC UPSes, that ran > the data center. The AC ran off of the diesel generators and grid power. > We ran full time off the APC UPSes, > and if the commercial power failed, we automatically brought up all 3 > generators. Assuming one would fail, > the others could carry the full load. If one did not fail, the one with the > longest run time in the logs would be > shout down. The UPSes were big enough to run the data center at full load > for about 20 minutes, but it should > be no more than 60 seconds before we were on generator power if commercial > failed, or was out for more than a few > moments. > > In the old days I worked on IBM mainframes, and a small mainframe (4341 if I > remember right) had a generator > set to help isolate the power. Internal to that machine the generator set > generated 400Hz, but we fed it from our > commercial building power into the generator. It was not mechanically > efficient, but it kept the machine going. > The HVAC was on regular building power. ,,, Even at larger datacenters where > I worked, the idea was enough > building UPS to keep the computer and networking going. The UPS and > building HVAC and a few essential > services were powered by the generator sets if commercial power died, and we > tried to have power fed from two > or more separate sub-stations linked to different parts of the 'grid'. One > side on the same 'grid feed' as a local > hospital or two if possible ... their power seems to get fixed first :) ... > but at the ones where I was, no major > fly wheel storage or things like that. > -- > Increase Visibility of Your 3D Game App& Earn a Chance To Win $500! > Tap into the largest installed PC base& get more eyes on your game by > optimizing for Intel(R) Graphics Technology. Get started today with the > Intel(R) Software Partner Program. Five $500 cash prizes are up for grabs. > http://p.sf.net/sfu/intelisp-dev2dev > ___ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users > > > - > No virus found in this message. > Checked by AVG - www.avg.com > Version: 10.0.1153 / Virus Database: 424/3274 - Release Date: 11/23/10 > > -- Increase Visibility of Your 3D Game App & Earn a Chance To Win $500! Tap into the largest installed PC base & get more eyes on your game by optimizing for Intel(R) Graphics Technology. Get started today with the Intel(R) Software Partner Program. Five $500 cash prizes are up for grabs. http://p.sf.net/sfu/intelisp-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Seeking ideas how to sync an AC generator to 60 HZ average.
On Tue, Nov 23, 2010 at 1:14 PM, Igor Chudov wrote: > On Tue, Nov 23, 2010 at 12:10 PM, Andy Pugh wrote: >> On 23 November 2010 16:52, Dave wrote: >> >>> Apparently there is a large DC inverter station out in the northwest?? >>> that is used to allow different synchronization of the grids >> >> I think that might be to prevent the US grid being a rather efficient >> antenna and radiating half the energy into space. >> >> 60Hz x speed of light = 3000 miles. > > But, but, the wires usually go in pairs (or threes for three phase), > would that not cancel out the antenna effects? Common configuration of HV lines returns through earth, to save the cost of wire. http://en.wikipedia.org/wiki/High-voltage_direct_current -- Increase Visibility of Your 3D Game App & Earn a Chance To Win $500! Tap into the largest installed PC base & get more eyes on your game by optimizing for Intel(R) Graphics Technology. Get started today with the Intel(R) Software Partner Program. Five $500 cash prizes are up for grabs. http://p.sf.net/sfu/intelisp-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Seeking ideas how to sync an AC generator to 60 HZ average.
I helped build a 'small data center', we put in 3 1MW diesel generators to feed two 1MW APC UPSes, that ran the data center. The AC ran off of the diesel generators and grid power. We ran full time off the APC UPSes, and if the commercial power failed, we automatically brought up all 3 generators. Assuming one would fail, the others could carry the full load. If one did not fail, the one with the longest run time in the logs would be shout down. The UPSes were big enough to run the data center at full load for about 20 minutes, but it should be no more than 60 seconds before we were on generator power if commercial failed, or was out for more than a few moments. In the old days I worked on IBM mainframes, and a small mainframe (4341 if I remember right) had a generator set to help isolate the power. Internal to that machine the generator set generated 400Hz, but we fed it from our commercial building power into the generator. It was not mechanically efficient, but it kept the machine going. The HVAC was on regular building power. ,,, Even at larger datacenters where I worked, the idea was enough building UPS to keep the computer and networking going. The UPS and building HVAC and a few essential services were powered by the generator sets if commercial power died, and we tried to have power fed from two or more separate sub-stations linked to different parts of the 'grid'. One side on the same 'grid feed' as a local hospital or two if possible ... their power seems to get fixed first :) ... but at the ones where I was, no major fly wheel storage or things like that. -- Increase Visibility of Your 3D Game App & Earn a Chance To Win $500! Tap into the largest installed PC base & get more eyes on your game by optimizing for Intel(R) Graphics Technology. Get started today with the Intel(R) Software Partner Program. Five $500 cash prizes are up for grabs. http://p.sf.net/sfu/intelisp-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Seeking ideas how to sync an AC generator to 60 HZ average.
At one time I heard there were legal reasons that caused the 'grid' to keep frequency long term stable. This is why AC clocks are basically 'never off', the frequency does vary, but within 24 hours they still must have generated the same number of 'cycles'. This allows them to 'slow' the cycles or 'speed up' a bit, but still counting cycles over a long period is what makes it appears so frequency stable. ... just my thoughts. -- Increase Visibility of Your 3D Game App & Earn a Chance To Win $500! Tap into the largest installed PC base & get more eyes on your game by optimizing for Intel(R) Graphics Technology. Get started today with the Intel(R) Software Partner Program. Five $500 cash prizes are up for grabs. http://p.sf.net/sfu/intelisp-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Seeking ideas how to sync an AC generator to 60 HZ average.
Keeping exactly 60Hz isn't that critical. The real timing is being done by crystals and the clock can be set using a little GPS or even easier NTP software if you have reasonable internet access. Are you considering staying in sync if commercial power fails? For computer loads UPSes are great, but their frequency does drift a little. For industrial applications (like EMC2 :) even if it is 'home industry' ) exact timing doesn't matter, unless you are planning on 'grid tie' your shop to the grid. Then you should look into the 'grid tie' hardware that the solar and wind folks use. They have been doing it for a long time now (10+ years) and have it down. Personally I would like to have a 'off the grid' shop. Solar for lights and light work, kick in a generator when 'real power' is needed, and as an optional battery recharger. I guess it is just the little bit of 'green geek' in me that wants that. But since I don't have a 'shop' I can dream. Practicality says that building it and tie it to the grid and just pay the bills makes the most economic sense in the short to mid-term (2 to 10 years) to me. -- Increase Visibility of Your 3D Game App & Earn a Chance To Win $500! Tap into the largest installed PC base & get more eyes on your game by optimizing for Intel(R) Graphics Technology. Get started today with the Intel(R) Software Partner Program. Five $500 cash prizes are up for grabs. http://p.sf.net/sfu/intelisp-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Seeking ideas how to sync an AC generator to 60 HZ average.
Dave wrote: > Interesting. > > Apparently there is a large DC inverter station out in the northwest?? > that is used to allow different synchronization of the grids in the > eastern US with the western US or across some other regional divide. > > Sort of like a giant AC drive taken to an entirely different level.. ;-) > > My understanding is that most of the time the Eastern and Western grids are not tied, but that during shortages, they can interconnect that way. Many years ago, maybe in the 1960's or so, they tried a direct AC interconnect across the Hoover Dam, which bridges the two grids. The system became unstable, as they had two big pools with a HUGE length of transmission lines between them, thus a large inductor between what acted somewhat like two big capacitors. They developed a large amount of reactive power flowing back and forth between the two systems at a rate of a couple Hz, or maybe it was below one Hz. Anyway, they later installed a huge cycloconverter that could couple the two systems without regard to phase angle, and send power whichever way it was needed. Jon -- Increase Visibility of Your 3D Game App & Earn a Chance To Win $500! Tap into the largest installed PC base & get more eyes on your game by optimizing for Intel(R) Graphics Technology. Get started today with the Intel(R) Software Partner Program. Five $500 cash prizes are up for grabs. http://p.sf.net/sfu/intelisp-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Seeking ideas how to sync an AC generator to 60 HZ average.
Ian W. Wright wrote: > > Yes, you're right but I'm not sure how close they ahere to > that nowadays. With the common frequency dips due to load > problems and the tendency for people to convert to quartz > timing instead of mains synchronous, I wonder if they bother > so much or whether they just try to get it right weekly or > some such. Maybe I'll put a mains frequency monitor on here > out of interest - its 13 years since I retired from the > ratrace of chasing power around plant rooms.. > > We have several line-synched electronic clocks here, and they all keep excellent time. So, it seems the utility here (and thus, the entire midwest-US electric grid) maintains very good long-term synch. In fact, these line-sync clocks are more accurate than the clocks in some of my computers that do not have NTP running to correct their drift. Jon -- Increase Visibility of Your 3D Game App & Earn a Chance To Win $500! Tap into the largest installed PC base & get more eyes on your game by optimizing for Intel(R) Graphics Technology. Get started today with the Intel(R) Software Partner Program. Five $500 cash prizes are up for grabs. http://p.sf.net/sfu/intelisp-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Seeking ideas how to sync an AC generator to 60 HZ average.
Ian W. Wright wrote: > John, > > I think Andy was assuming that this power generator would be > backup for mains outages when, if the switchover were to be > automatic and seamless, If you want seamless transfer to emergency power, then the alternator needs to be online all the time. For big data centers, they have electronic UPS's and flywheel energy storage, but that is not really practical for small users. Jon -- Increase Visibility of Your 3D Game App & Earn a Chance To Win $500! Tap into the largest installed PC base & get more eyes on your game by optimizing for Intel(R) Graphics Technology. Get started today with the Intel(R) Software Partner Program. Five $500 cash prizes are up for grabs. http://p.sf.net/sfu/intelisp-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Seeking ideas how to sync an AC generator to 60 HZ average.
Leslie Newell wrote: > Generally they adjust the frequency throughout the day. As the load on > the system increases the frequency drops. To increase the frequency they > bring more generators on line. If the frequency gets too high they > reduce the generating capacity. The really tricky bit is matching > generating capacity to the load well enough to maintain a reasonably > accurate 50/60Hz > The power stations are self-synched to the overall grid. Opening the throttle on the turbines acts to increase frequency, but due to the enormous stiffness of all the alternators, many of the throttles have to be opened wider and then the frequency starts to rise very slowly. So, it is a VERY tricky and slightly unstable network. You can measure the effect of each individual alternator by measuring the phase angle between current and voltage, although that gets complicated by the excitation level of the alternator. Reducing field excitation causes the alternator to produce current that lags the voltage, like an induction motor, and increasing the excitation causes current to lead the voltage. Experts have tried to model the whole grid, and found it to be very nearly mathematically intractable. Resistance and leakage inductance in transformers, etc. are the only thing keeping the grid (barely) stable. Jon -- Increase Visibility of Your 3D Game App & Earn a Chance To Win $500! Tap into the largest installed PC base & get more eyes on your game by optimizing for Intel(R) Graphics Technology. Get started today with the Intel(R) Software Partner Program. Five $500 cash prizes are up for grabs. http://p.sf.net/sfu/intelisp-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Seeking ideas how to sync an AC generator to 60 HZ average.
On Tue, Nov 23, 2010 at 12:10 PM, Andy Pugh wrote: > On 23 November 2010 16:52, Dave wrote: > >> Apparently there is a large DC inverter station out in the northwest?? >> that is used to allow different synchronization of the grids in the >> eastern US with the western US or across some other regional divide. > > I think that might be to prevent the US grid being a rather efficient > antenna and radiating half the energy into space. > > 60Hz x speed of light = 3000 miles. But, but, the wires usually go in pairs (or threes for three phase), would that not cancel out the antenna effects? i -- Increase Visibility of Your 3D Game App & Earn a Chance To Win $500! Tap into the largest installed PC base & get more eyes on your game by optimizing for Intel(R) Graphics Technology. Get started today with the Intel(R) Software Partner Program. Five $500 cash prizes are up for grabs. http://p.sf.net/sfu/intelisp-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Seeking ideas how to sync an AC generator to 60 HZ average.
Andy Pugh wrote: > Doesn't it need to be synched to mains frequency rather than absolute > time? How accurate is NTP (or even GPS time) in this context? > ... > The GPS system has atomic clocks accurate to some insane level like one second in 10,000 years. They have to periodically adjust the clocks for relativistic effects. The satellites transmit time to receivers on earth, and the time code system can resolve the broadcast time to a nanosecond - literally. Then, after solving the equations for path delay from several satellites, the position can be fixed, and so the real time on an arbitrary point on earth can be determined to great precision. NTP is supposed to be good to well within a second, assuming any decent net connection. On the other hand, unless this generator is extremely reliable and run 24/7 constantly for months, trying to sync electric clocks to it seems a poor choice. Maybe find a good computer with a good real time clock on it and have it "broadcast" time over a serial line to remote time displays. That's what I do here, and Linux even automatically corrects the time for daylight savings time twice a year. (I also have temperature and humidity sensors, so the displays show time, date, temp and humidity at convenient locations.) Jon -- Increase Visibility of Your 3D Game App & Earn a Chance To Win $500! Tap into the largest installed PC base & get more eyes on your game by optimizing for Intel(R) Graphics Technology. Get started today with the Intel(R) Software Partner Program. Five $500 cash prizes are up for grabs. http://p.sf.net/sfu/intelisp-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Seeking ideas how to sync an AC generator to 60 HZ average.
On 23 November 2010 16:52, Dave wrote: > Apparently there is a large DC inverter station out in the northwest?? > that is used to allow different synchronization of the grids in the > eastern US with the western US or across some other regional divide. I think that might be to prevent the US grid being a rather efficient antenna and radiating half the energy into space. 60Hz x speed of light = 3000 miles. -- atp -- Increase Visibility of Your 3D Game App & Earn a Chance To Win $500! Tap into the largest installed PC base & get more eyes on your game by optimizing for Intel(R) Graphics Technology. Get started today with the Intel(R) Software Partner Program. Five $500 cash prizes are up for grabs. http://p.sf.net/sfu/intelisp-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Seeking ideas how to sync an AC generator to 60 HZ average.
Interesting. Apparently there is a large DC inverter station out in the northwest?? that is used to allow different synchronization of the grids in the eastern US with the western US or across some other regional divide. Sort of like a giant AC drive taken to an entirely different level.. ;-) I remember finding it via a google lookup one time. Dave On 11/23/2010 11:25 AM, dave wrote: > 50 some years ago a couple of engineers came to Coulee from the Denver > office (USBR) and installed a mag amp in feed forward mode to control > the penstock gate on one of the small units. This was before the third > powerhouse so the units were all 108 Mw. This one unit was used to swing > the entire Northwest Power Pool ( OR, WA, ID, UT, and most of MT and > WY ). I don't have any quantitative figures but the frequency regulation > got 10X better. > > Dave > > On Tue, 2010-11-23 at 17:17 +0200, Roland Jollivet wrote: > >> I heard once (here in SA) that the mains cycles were adjusted close to >> midnight, so that the number remained consistent on a daily basis. I don't >> know how it's arranged though, since there are so many power stations to >> sync. >> >> Regards >> Roland >> >> >> >> >> On 23 November 2010 16:49, Ian W. Wright wrote: >> >> >>> On 23/11/2010 14:37, Andy Pugh wrote: >>> On 23 November 2010 14:31, Ian W. Wright >>> wrote: >>> > hell, I've seen our mains frequency > vary from 47 to 54 Hz over the day many times depending on > the load and no one ever complains... > Though supposedly you should still always get 432 cycles per day. >>> Yes, you're right but I'm not sure how close they ahere to >>> that nowadays. With the common frequency dips due to load >>> problems and the tendency for people to convert to quartz >>> timing instead of mains synchronous, I wonder if they bother >>> so much or whether they just try to get it right weekly or >>> some such. Maybe I'll put a mains frequency monitor on here >>> out of interest - its 13 years since I retired from the >>> ratrace of chasing power around plant rooms.. >>> >>> Ian >>> >>> >>> -- >>> Increase Visibility of Your 3D Game App& Earn a Chance To Win $500! >>> Tap into the largest installed PC base& get more eyes on your game by >>> optimizing for Intel(R) Graphics Technology. Get started today with the >>> Intel(R) Software Partner Program. Five $500 cash prizes are up for grabs. >>> http://p.sf.net/sfu/intelisp-dev2dev >>> ___ >>> Emc-users mailing list >>> Emc-users@lists.sourceforge.net >>> https://lists.sourceforge.net/lists/listinfo/emc-users >>> >>> >> -- >> Increase Visibility of Your 3D Game App& Earn a Chance To Win $500! >> Tap into the largest installed PC base& get more eyes on your game by >> optimizing for Intel(R) Graphics Technology. Get started today with the >> Intel(R) Software Partner Program. Five $500 cash prizes are up for grabs. >> http://p.sf.net/sfu/intelisp-dev2dev >> ___ >> Emc-users mailing list >> Emc-users@lists.sourceforge.net >> https://lists.sourceforge.net/lists/listinfo/emc-users >> > > -- > Increase Visibility of Your 3D Game App& Earn a Chance To Win $500! > Tap into the largest installed PC base& get more eyes on your game by > optimizing for Intel(R) Graphics Technology. Get started today with the > Intel(R) Software Partner Program. Five $500 cash prizes are up for grabs. > http://p.sf.net/sfu/intelisp-dev2dev > ___ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users > > -- Increase Visibility of Your 3D Game App & Earn a Chance To Win $500! Tap into the largest installed PC base & get more eyes on your game by optimizing for Intel(R) Graphics Technology. Get started today with the Intel(R) Software Partner Program. Five $500 cash prizes are up for grabs. http://p.sf.net/sfu/intelisp-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Seeking ideas how to sync an AC generator to 60 HZ average.
50 some years ago a couple of engineers came to Coulee from the Denver office (USBR) and installed a mag amp in feed forward mode to control the penstock gate on one of the small units. This was before the third powerhouse so the units were all 108 Mw. This one unit was used to swing the entire Northwest Power Pool ( OR, WA, ID, UT, and most of MT and WY ). I don't have any quantitative figures but the frequency regulation got 10X better. Dave On Tue, 2010-11-23 at 17:17 +0200, Roland Jollivet wrote: > I heard once (here in SA) that the mains cycles were adjusted close to > midnight, so that the number remained consistent on a daily basis. I don't > know how it's arranged though, since there are so many power stations to > sync. > > Regards > Roland > > > > > On 23 November 2010 16:49, Ian W. Wright wrote: > > > On 23/11/2010 14:37, Andy Pugh wrote: > > > On 23 November 2010 14:31, Ian W. Wright > > wrote: > > > > > >> hell, I've seen our mains frequency > > >> vary from 47 to 54 Hz over the day many times depending on > > >> the load and no one ever complains... > > > Though supposedly you should still always get 432 cycles per day. > > > > > Yes, you're right but I'm not sure how close they ahere to > > that nowadays. With the common frequency dips due to load > > problems and the tendency for people to convert to quartz > > timing instead of mains synchronous, I wonder if they bother > > so much or whether they just try to get it right weekly or > > some such. Maybe I'll put a mains frequency monitor on here > > out of interest - its 13 years since I retired from the > > ratrace of chasing power around plant rooms.. > > > > Ian > > > > > > -- > > Increase Visibility of Your 3D Game App & Earn a Chance To Win $500! > > Tap into the largest installed PC base & get more eyes on your game by > > optimizing for Intel(R) Graphics Technology. Get started today with the > > Intel(R) Software Partner Program. Five $500 cash prizes are up for grabs. > > http://p.sf.net/sfu/intelisp-dev2dev > > ___ > > Emc-users mailing list > > Emc-users@lists.sourceforge.net > > https://lists.sourceforge.net/lists/listinfo/emc-users > > > -- > Increase Visibility of Your 3D Game App & Earn a Chance To Win $500! > Tap into the largest installed PC base & get more eyes on your game by > optimizing for Intel(R) Graphics Technology. Get started today with the > Intel(R) Software Partner Program. Five $500 cash prizes are up for grabs. > http://p.sf.net/sfu/intelisp-dev2dev > ___ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users -- Increase Visibility of Your 3D Game App & Earn a Chance To Win $500! Tap into the largest installed PC base & get more eyes on your game by optimizing for Intel(R) Graphics Technology. Get started today with the Intel(R) Software Partner Program. Five $500 cash prizes are up for grabs. http://p.sf.net/sfu/intelisp-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Seeking ideas how to sync an AC generator to 60 HZ average.
Generally they adjust the frequency throughout the day. As the load on the system increases the frequency drops. To increase the frequency they bring more generators on line. If the frequency gets too high they reduce the generating capacity. The really tricky bit is matching generating capacity to the load well enough to maintain a reasonably accurate 50/60Hz Les On 23/11/2010 15:17, Roland Jollivet wrote: > I heard once (here in SA) that the mains cycles were adjusted close to > midnight, so that the number remained consistent on a daily basis. I don't > know how it's arranged though, since there are so many power stations to > sync. > > Regards > Roland -- Increase Visibility of Your 3D Game App & Earn a Chance To Win $500! Tap into the largest installed PC base & get more eyes on your game by optimizing for Intel(R) Graphics Technology. Get started today with the Intel(R) Software Partner Program. Five $500 cash prizes are up for grabs. http://p.sf.net/sfu/intelisp-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Seeking ideas how to sync an AC generator to 60 HZ average.
I heard once (here in SA) that the mains cycles were adjusted close to midnight, so that the number remained consistent on a daily basis. I don't know how it's arranged though, since there are so many power stations to sync. Regards Roland On 23 November 2010 16:49, Ian W. Wright wrote: > On 23/11/2010 14:37, Andy Pugh wrote: > > On 23 November 2010 14:31, Ian W. Wright > wrote: > > > >> hell, I've seen our mains frequency > >> vary from 47 to 54 Hz over the day many times depending on > >> the load and no one ever complains... > > Though supposedly you should still always get 432 cycles per day. > > > Yes, you're right but I'm not sure how close they ahere to > that nowadays. With the common frequency dips due to load > problems and the tendency for people to convert to quartz > timing instead of mains synchronous, I wonder if they bother > so much or whether they just try to get it right weekly or > some such. Maybe I'll put a mains frequency monitor on here > out of interest - its 13 years since I retired from the > ratrace of chasing power around plant rooms.. > > Ian > > > -- > Increase Visibility of Your 3D Game App & Earn a Chance To Win $500! > Tap into the largest installed PC base & get more eyes on your game by > optimizing for Intel(R) Graphics Technology. Get started today with the > Intel(R) Software Partner Program. Five $500 cash prizes are up for grabs. > http://p.sf.net/sfu/intelisp-dev2dev > ___ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users > -- Increase Visibility of Your 3D Game App & Earn a Chance To Win $500! Tap into the largest installed PC base & get more eyes on your game by optimizing for Intel(R) Graphics Technology. Get started today with the Intel(R) Software Partner Program. Five $500 cash prizes are up for grabs. http://p.sf.net/sfu/intelisp-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Seeking ideas how to sync an AC generator to 60 HZ average.
On 23/11/2010 14:37, Andy Pugh wrote: > On 23 November 2010 14:31, Ian W. Wright wrote: > >> hell, I've seen our mains frequency >> vary from 47 to 54 Hz over the day many times depending on >> the load and no one ever complains... > Though supposedly you should still always get 432 cycles per day. > Yes, you're right but I'm not sure how close they ahere to that nowadays. With the common frequency dips due to load problems and the tendency for people to convert to quartz timing instead of mains synchronous, I wonder if they bother so much or whether they just try to get it right weekly or some such. Maybe I'll put a mains frequency monitor on here out of interest - its 13 years since I retired from the ratrace of chasing power around plant rooms.. Ian -- Increase Visibility of Your 3D Game App & Earn a Chance To Win $500! Tap into the largest installed PC base & get more eyes on your game by optimizing for Intel(R) Graphics Technology. Get started today with the Intel(R) Software Partner Program. Five $500 cash prizes are up for grabs. http://p.sf.net/sfu/intelisp-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Seeking ideas how to sync an AC generator to 60 HZ average.
On 11/23/2010 9:23 AM, Andy Pugh wrote: > On 23 November 2010 14:06, John Kasunich wrote: > > >>> My next project is a remote off grid 60 HZ power unit. >>> >> I think this has nothing to do with transitions to/from utility >> power. >> > Ah, in that case, why does it matter? > > Not sure. Generally when generators take over after a power outage they don't try and maintain sync with the utility since the utility has no power on the lines to synch with. When the power comes back up, the generator speed is synced to the line and the transfer is made back to the utility. I remember back in college that we had a lab experiment in my power class where we did an actual manual power transfer to and from the utility lines with a generator. Back then they used 3 light bulbs connected L1 to L1, L2 to L2, L3 to L3 between the generator and the utility lines.When all three light bulbs went out the generator was in synch with the line and you could open and close the transfer switch. Some wise guy wanted to see what would happen if you threw the switch when things were out of sync.. so he threw the switch and we all got to hear the bang when the generator was pulled into sync by the utility. The professor was not amused.I distinctly remember that prof as he later tried to throw me out of college after I found he was using out of date materials and I was forced to confront him with it. Not my best college memory. Fortunately I prevailed, and the department chair assigned a different prof as my advisor. Dave -- Increase Visibility of Your 3D Game App & Earn a Chance To Win $500! Tap into the largest installed PC base & get more eyes on your game by optimizing for Intel(R) Graphics Technology. Get started today with the Intel(R) Software Partner Program. Five $500 cash prizes are up for grabs. http://p.sf.net/sfu/intelisp-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Seeking ideas how to sync an AC generator to 60 HZ average.
On 23 November 2010 14:31, Ian W. Wright wrote: > hell, I've seen our mains frequency > vary from 47 to 54 Hz over the day many times depending on > the load and no one ever complains... Though supposedly you should still always get 432 cycles per day. -- atp -- Increase Visibility of Your 3D Game App & Earn a Chance To Win $500! Tap into the largest installed PC base & get more eyes on your game by optimizing for Intel(R) Graphics Technology. Get started today with the Intel(R) Software Partner Program. Five $500 cash prizes are up for grabs. http://p.sf.net/sfu/intelisp-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Seeking ideas how to sync an AC generator to 60 HZ average.
Sounds like mainly he want his old 60cycle clocks to work correctly. :) sam On 11/23/2010 8:23 AM, Andy Pugh wrote: > On 23 November 2010 14:06, John Kasunich wrote: > >>> My next project is a remote off grid 60 HZ power unit. >> I think this has nothing to do with transitions to/from utility >> power. > Ah, in that case, why does it matter? > -- Increase Visibility of Your 3D Game App & Earn a Chance To Win $500! Tap into the largest installed PC base & get more eyes on your game by optimizing for Intel(R) Graphics Technology. Get started today with the Intel(R) Software Partner Program. Five $500 cash prizes are up for grabs. http://p.sf.net/sfu/intelisp-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Seeking ideas how to sync an AC generator to 60 HZ average.
John, I think Andy was assuming that this power generator would be backup for mains outages when, if the switchover were to be automatic and seamless, it would indeed to essential to get the generator frequency very close to mains frequency and, more importantly, the phases in the correct rotational relationship before switch back to the mains. It took ages for the supplier's techs to get this right on the 2 x 1100Hp deisel gennys I had at work If this genny is to completely stand-alone off in the woods somewhere - I don't really see why it needs tying to any major time standard - what's going to power a PC while the genny gets up and running anyway? Normally engine governors or feedback electronics should keep the frequency within limits anyway - hell, I've seen our mains frequency vary from 47 to 54 Hz over the day many times depending on the load and no one ever complains... Ian _ Ian W. Wright Sheffield UK -- Increase Visibility of Your 3D Game App & Earn a Chance To Win $500! Tap into the largest installed PC base & get more eyes on your game by optimizing for Intel(R) Graphics Technology. Get started today with the Intel(R) Software Partner Program. Five $500 cash prizes are up for grabs. http://p.sf.net/sfu/intelisp-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Seeking ideas how to sync an AC generator to 60 HZ average.
On 23 November 2010 14:06, John Kasunich wrote: >> My next project is a remote off grid 60 HZ power unit. > > I think this has nothing to do with transitions to/from utility > power. Ah, in that case, why does it matter? -- atp -- Increase Visibility of Your 3D Game App & Earn a Chance To Win $500! Tap into the largest installed PC base & get more eyes on your game by optimizing for Intel(R) Graphics Technology. Get started today with the Intel(R) Software Partner Program. Five $500 cash prizes are up for grabs. http://p.sf.net/sfu/intelisp-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Seeking ideas how to sync an AC generator to 60 HZ average.
On Tue, 23 Nov 2010 10:16 +, "Andy Pugh" wrote: > > Doesn't it need to be synched to mains frequency rather than absolute > time? (snip) > However, what is really needed is to keep synch with the local mains > during outages, (snip) > When the mains comes back you could use the PID to bring the generator > back in to phase before switching back over. The original poster wrote: > My next project is a remote off grid 60 HZ power unit. I think this has nothing to do with transitions to/from utility power. John -- John Kasunich jmkasun...@fastmail.fm -- Increase Visibility of Your 3D Game App & Earn a Chance To Win $500! Tap into the largest installed PC base & get more eyes on your game by optimizing for Intel(R) Graphics Technology. Get started today with the Intel(R) Software Partner Program. Five $500 cash prizes are up for grabs. http://p.sf.net/sfu/intelisp-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Seeking ideas how to sync an AC generator to 60 HZ average.
On 23 November 2010 05:17, John Kasunich wrote: > > Do you have internet access at the site? > > If you are running an PC for EMC, you can use NTP to keep > the PC's clock synced to the rest of the world Doesn't it need to be synched to mains frequency rather than absolute time? How accurate is NTP (or even GPS time) in this context? ... http://gpsinformation.net/main/gpstime.htm seems to think that is it close enough. However, what is really needed is to keep synch with the local mains during outages, and that might be better done by a local clock. You could potentially use siggen with a PID to correct phase, then lock the PID when mains voltage is lost. PID dosn't have a "lock" pin, so you would probably need to use a sample_hold. When the mains comes back you could use the PID to bring the generator back in to phase before switching back over. (and it probably wouldn't drift that much anyway) -- atp -- Increase Visibility of Your 3D Game App & Earn a Chance To Win $500! Tap into the largest installed PC base & get more eyes on your game by optimizing for Intel(R) Graphics Technology. Get started today with the Intel(R) Software Partner Program. Five $500 cash prizes are up for grabs. http://p.sf.net/sfu/intelisp-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Seeking ideas how to sync an AC generator to 60 HZ average.
A cheap USB GPS can be used to extract the time off the satellite signal. Easier to interface to than a Walmart Atomic clock. I have a couple of those "Atomic" clocks and they sometimes get confused. Dave On 11/23/2010 12:11 AM, Don Stanley wrote: > Hi All; > My next project is a remote off grid 60 HZ power unit. > I am thinking of a EMC2 PID to control the RPM. > I am also expecting maybe a 1-2 HZ momentary shift as the > big power loads come on and off line. > > I am looking for a method to get a reliable reference that can be used to > average 60 HZ through the power surges and correct a local timer drift > for long term accuracy. A simple WWV corrected timer > (a Wall mart Atomic clock with outputs). > Anyone know of such a device? > > Thanks > Don > -- > Increase Visibility of Your 3D Game App& Earn a Chance To Win $500! > Tap into the largest installed PC base& get more eyes on your game by > optimizing for Intel(R) Graphics Technology. Get started today with the > Intel(R) Software Partner Program. Five $500 cash prizes are up for grabs. > http://p.sf.net/sfu/intelisp-dev2dev > ___ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users > > -- Increase Visibility of Your 3D Game App & Earn a Chance To Win $500! Tap into the largest installed PC base & get more eyes on your game by optimizing for Intel(R) Graphics Technology. Get started today with the Intel(R) Software Partner Program. Five $500 cash prizes are up for grabs. http://p.sf.net/sfu/intelisp-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Seeking ideas how to sync an AC generator to 60 HZ average.
Do you have internet access at the site? If you are running an PC for EMC, you can use NTP to keep the PC's clock synced to the rest of the world, and some HAL bits and pieces to keep the generator synced to the PC clock. EMC's encoder component could easily count 60Hz. On Tue, 23 Nov 2010 00:11 -0500, "Don Stanley" wrote: > Hi All; > My next project is a remote off grid 60 HZ power unit. > I am thinking of a EMC2 PID to control the RPM. > I am also expecting maybe a 1-2 HZ momentary shift as the > big power loads come on and off line. > > I am looking for a method to get a reliable reference that can be used to > average 60 HZ through the power surges and correct a local timer drift > for long term accuracy. A simple WWV corrected timer > (a Wall mart Atomic clock with outputs). > Anyone know of such a device? > > Thanks > Don > -- > Increase Visibility of Your 3D Game App & Earn a Chance To Win $500! > Tap into the largest installed PC base & get more eyes on your game by > optimizing for Intel(R) Graphics Technology. Get started today with the > Intel(R) Software Partner Program. Five $500 cash prizes are up for > grabs. > http://p.sf.net/sfu/intelisp-dev2dev > ___ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users > -- John Kasunich jmkasun...@fastmail.fm -- Increase Visibility of Your 3D Game App & Earn a Chance To Win $500! Tap into the largest installed PC base & get more eyes on your game by optimizing for Intel(R) Graphics Technology. Get started today with the Intel(R) Software Partner Program. Five $500 cash prizes are up for grabs. http://p.sf.net/sfu/intelisp-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
[Emc-users] Seeking ideas how to sync an AC generator to 60 HZ average.
Hi All; My next project is a remote off grid 60 HZ power unit. I am thinking of a EMC2 PID to control the RPM. I am also expecting maybe a 1-2 HZ momentary shift as the big power loads come on and off line. I am looking for a method to get a reliable reference that can be used to average 60 HZ through the power surges and correct a local timer drift for long term accuracy. A simple WWV corrected timer (a Wall mart Atomic clock with outputs). Anyone know of such a device? Thanks Don -- Increase Visibility of Your 3D Game App & Earn a Chance To Win $500! Tap into the largest installed PC base & get more eyes on your game by optimizing for Intel(R) Graphics Technology. Get started today with the Intel(R) Software Partner Program. Five $500 cash prizes are up for grabs. http://p.sf.net/sfu/intelisp-dev2dev ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
