Francis Grosz

Folks, One thing that is sometimes poorly understood is that on a power system real power flow (Watts)is primarily determined by phase; voltage determines reactive power flow (VARs). This means power system operators are very interested in the phase difference between the two ends of a transmission line, for example. GPS has made it possible to measure this accurately even over long distances using purpose-built instruments. Google "Phasor Measurement Units" got more information. Francis Grosz -------------------------------------------------- Message: 2 Date: Mon, 19 Dec 2016 11:46:41 -0500 From: Bob Camp <kb8tq@n1k.org> To: Tom Van Baak <tvb@leapsecond.com>, Discussion of precise time and frequency measurement <time-nuts@febo.com> Subject: Re: [time-nuts] 1PPS users? Message-ID: <F2624A9E-FDBF-4EC4-8835-16B4A7A0CA0A@n1k.org> Content-Type: text/plain; charset=utf-8 Hi > On Dec 19, 2016, at 10:11 AM, Tom Van Baak <tvb@LeapSecond.com> wrote: > >> I believe the power industry is using GPS provided time to stamp power >> events for analysis as well. > > Chris, > > Yes, in fact one of the first applications of hp's SmartClock was just that: > > "Accurate Transmission Line Fault Location Using Synchronized Sampling" > http://leapsecond.com/hpan/an1276-1.pdf There is an FCS paper that pre-dates that by about a decade. The guys at Quebec Hydro set up GPS to monitor the phase state in their main distribution network and wrote the paper. I don’t have an FCS DVD handy to dig it up. I also have no idea if there is a copy outside a pay wall. They went into a bit more detail on what they saw. It gives you a bit better feel for how it works in the real world. Bob > > > Bob, > > For more background on 1PPS and time synchronization see: > > "GPS and Precision Timing Applications" > http://www.hpmemoryproject.org/an/pdf/an_1272.pdf > > "The Global Positioning System and HP SmartClock" > http://www.hpl.hp.com/hpjournal/96dec/dec96a9.pdf > > Other useful hp app notes for time nuts: > http://leapsecond.com/hpan/list.htm > > /tvb > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there.