재신정보 > 전기품질,에너지측정,진단,절감분야 > PSL사 알렉스회장의 뉴스레터 - 2011.11 - In this Electric Power Quality Newsletter

Sascha vonMeier's Grid Time-Distance Scales

Professor von Meier's Time and Distance Scales for the power grid

Here's a fascinating new way to look at electric power grids. Professor von Meier of the California Institute for Energy and Environment in Berkeley has drawn two scales: the first shows grid activities vs time, and the second shows grid activities vs distance. The scales are logarithmic, and give a good general sense of how long, and how far, things happen on the grid.

It's a mind-opening way of looking at topics that don't generally get related to each other - great fun if you like to play with ideas about the power grid.

If you're not familiar with the electric grid acronymns on the picture above, here's some help: "AGC" refers to automatic generator control loops (I think); "T&D" refers to transmission and distribution systems; "DG interconnection" refers to Distributed Generation, such as photovoltaics, wind turbines, fuel cells, etc.; "CAISO" is the California Independent System Operator which operates the wholesale market for power in California at caiso.com; and "WECC" is the Western Electricity Coordinating Council, which manages bulk electricity throughout the western United States and western Canada.

Click on map.pqube.com to investigate real-time data, recorded all over the world. Can you spot some of Sascha's time-scale and distance-scale effects, perhaps across the Western Europe grid, or the Western United States grid?

Superb new Power Quality Report Writer program (and it's FREE!)

It's difficult to write compliance Reports for standards like EN50160. There are hundreds of complicated requirements, and -- if you're like me -- the details quickly get overwhelming.

At PSL we've found a great solution.

A team led by Juliana Correa spent months writing the PQube Report Writer program, and it's now polished to the point where it's really easy to use. All you have to do is give it some data from a PQube power monitor, then choose a Standard - it's optimized for EN50160. Juliana's program then writes an absolutely beautiful Report, in -- get this -- Microsoft Word. So you can edit it and tweak it and make it look just the way you want, and deliver it to your client or customer.

This is a one of the best programs I've ever worked with. It's so great, and so much fun, that we're releasing it for FREE. Just download it here. The download even includes complete sample data so you can try writing a Report immediately.

The PQube Report Writer program comes pre-loaded with all 6 versions of EN50160, and pre-loaded with 7 common languages, but you can easily add your own Standards and Norms, and add your own language too if you want.

There's a fun little video of this program, hard at work - do take a quick look at it. I think there's something amusing about watching a program write a report in Microsoft Word. Or maybe it's just that I'm tickled that we don't have to do it ourselves any write these reports ourselves any more.

Question: Budeanu VAR's or fundamental VAR's?

In my last newsletter, I asked for opinions about two kinds of Volt-Amp-Reactive definitions: the good old power triangle (or Budeanu) version of VAR's, which is the remainder when you geometrically subtract watts from volt-amps; and there's the fundamental version of VAR's, which is the volt-amps times the sine of the angle, at the fundamental frequency, between the voltage and the current.

The two definitions are equivalent if you don't have any harmonics. But these days, of course, there are almost always lots of current harmonics, and the two definitions produce different readings. That's why we include both definitions in the little low-cost lab-grade PQube monitor.

So when does the power triangle definition make sense, and when does it make more sense to use the fundamental definition?

I received too many replies to include them all, but there is a general practical consensus that the fundamental VAR's is the correct definition for selecting power factor correction capacitors, and that the old power triangle definition is "simpler", even if it isn't quite right.

I will let my old and admired friend Professor Alex Emanuel have the last word. He points out that there are, in practice, VAR's at the fundamental and VAR's at each harmonic, and in practice each one of these harmonic reactive powers "kicks" independently from the other and causes line power losses, thus their algebraic summation does not makes sense.

Most correspondents discussed single-phase definitions of VAR's. But when we get to three-phase situations it gets even more complicated - there are multiple angles to consider, and multiple sets of harmonics. Fortunately, the IEEE 1459 Standard has all the correct definitions. That's a fine piece of work (thank you, Alex E!).

PQube power monitors for space exploration: NASA, SpaceEx

We're seeing lots of interesting ways to use PQube power monitors in space exploration - on the ground, though, not in space! For example, NASA's Goldstone tracking stations use the bi-directional energy feature of PQube monitors to keep track of how much regenerated power they can capture from the motion of their huge dish antennas.

If your national space program needs precision power monitoring, the PQube is an excellent instrument for both precise power flow measurements and for power disturbance recording. Let me know - I would be glad to help.

PQube is GSA-approved, and FREE 2.0 Firmware Upgrade released!

After extensive evaluation, the U.S. government's General Services Agency has selected the PQube monitor for a GSA contact (Contract Number GS24F0066M), making it even easier for government agencies and the military to purchase PQubes. The PQube can also be purchased under NATO Contractor and Government Entity code 4DC50 - I'm not quite sure what that means, but apparently it's important to people who understand such things...

We've released the latest FREE upgrade to PQube firmware. The new 2.0 firmware adds some great new customer-requested features:

Powerful Configurator Software package for easy configuration of your PQube
New Report Writer software that writes Power Quality reports in Microsoft Word
Incandescent flicker measurements according to IEC 61000-4-15
Split-single-phase power configuration - often found in North American residences
Expanded choices in voltage and current harmonic measurements
PF, THD, VA, VAR, and Flicker for each individual phase, recorded in Excel CSV file
Expanded VAR measurements and recording, including a new VAR-hour accumulator
Extended RMS event buffers, optimized for FIDVR events
'Executive summary' emails, in addition to full-detail emails
More!

The new PQube 2.0 firmware includes all of the great PQube features like automatic emails, remote Modbus meters, and PQDIF files, of course, and it's compatible with all PQubes. Download it here - it's free...

Our long-time colleague Kai Sang Lock has announced an interesting conference on Power Systems EMC & Smart Grid, to be held in Singapore in May 2010. You can find more information at www.apemc2012.org.

If you would like to get together, I will be in the Washingon DC area in late November / early December at the GovGreen conference, at Dominion Power, and at several government agency - details at PowerStandards.com/SeminarsTraining.htm.

Recently I've enjoyed teaching seminars in Germany, Portugal, Belgium, and Holland. Want a 2012 seminar in your region? Please contact my colleague Andreas Eberhard at aeberhard@powerstandards.com. It would be a pleasure to visit with you!

With my best wishes for you to enjoy a peaceful and happy winter holiday -

Alex McEachern
Alex@PowerStandards.com
Power Standards Lab
2020 Challenger Drive
Alameda, California 94501 USA
TEL ++1-510-522-4400
FAX ++1-510-522-4455

(I have sent this e-mail to you at 'ceo@jsdata.co.kr', because you are on my personal world-wide list of 23,240 engineers, educators, and students interested in power quality. If you no longer wish to receive it, please let me know.)

ㅇ 핵심 기술 (전기품질, 누전분석, 축전지셀진단) 제안, 세미나 자료 다운로드 서비스 (2009.06 버전)

ㅇ 기타분야 :