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<watchma...@talktalk.net> wrote: >> >> >>> On 23/11/2010 14:37, Andy Pugh wrote: >>> >>>> On 23 November 2010 14:31, Ian W. Wright<watchma...@talktalk.net> >>>> >>> 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 4320000 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
