제 목 : 2008. 7. 10 (from Alex McEachern) In this Power Quality Newsletter:
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등록일 : 2008-07-15 10:01
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(from Alex McEachern) In this Power Quality Newsletter:
Voltage swells - are there any standards?
My old friend, Patxi Pazos of Iberdrola in Spain, asks an interesting question: are there any standards for voltage swells?
There are lots of standards for voltage sags/dips: IEC 61000-4-34
for testing dip immunity, for example.
Voltage swells -- brief increases in voltage, for a few cycles to a few seconds -- are less common than voltage dips, but they do happen. Certain types of unbalanced voltage dips can cause a voltage swell on a pair of phases, and voltage swells have been observed during instabilities in power systems that are equipped with distributed generators.
Although the phenomena of voltage swells is well known, I'm not familiar with any standards that set limits on voltage swells, either in amplitude or duration, or even any standards that give guidance on immunity to voltage swells. (Some military standards, such as U.S. MIL-STD-704E for aircraft power, do include voltage swells.)
Any ideas or suggestions? Please send me an e-mail at Alex@PowerStandards.com
Any standards for voltage swells?Back to top
Marco Mancilla joins PSL as Vice President of Sales
PSL continues to grow rapidly - we've just completed a round of investment that will fund our rapid expansion, especially in world-wide markets.
As part of our expansion, I'm very pleased that an almost life-long colleague, Marco Mancilla, has joined us at Power Standards Lab as our Vice President of Sales. Marco and I started working together almost a quarter of a century ago, when we both were young men. (Marco still is.)
Marco has extraordinary expertise in world-wide power issues, and his first language is Spanish - extra languages are always an important qualification here at Power Standards Lab. Please join Andreas, Barry, and me in welcoming Marco!
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Energy consumption and industrial equipment
With rapidly increasing energy costs, I've become more interested these days on energy consumption and carbon footprint, especially for industrial equipment.
Here's a brief article
I wrote on this topic for the semiconductor industry.
I'm starting to organize some international cooperation among experts in this area, from a variety of industries that use intelligent energy-intensive equipment: automobile, petrochemical, semiconductor, etc. Please let me know
if you would like to help.
I'm forming new group of experts on energy and industrial equipment - please tell me if you would like to be email@example.com
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Big academic discounts on PSL Industrial Power Corruptors
One of Marco Mancilla's first decisions is to increase the discount for world-wide universities on PSL's Industrial Power Corruptor
, the world's standard voltage dip generator.
The IPC is an critical tool for any university that wants to do research on voltage dip immunity, or equip a power quality lab.
More than 15 universities in the Americas, Europe, and Asia are using PSL's IPC for projects that range from testing industrial equipment with IEC 61000-4-34
voltage dips, to research on how white goods (washing machines, refrigerators, and other home appliances) respond to voltage dips and swells.
If you're at a university, and need an Industrial Power Corruptor, please contact Marco directly.
Contact Marco Mancilla about academic discounts on voltage sag generators.
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Harmonics Direction project - all wrapped up!
For three years, we've been working on a fascinating project: Is it possible to measure the direction to a harmonic source?
The answer, it turns out, is yes.
Under the leadership of CEATI
and with the funding of a number of important utility companies, Bill Moncrief, Mack Grady, Matthew Muh, and I have been struggling with this question. The problem, of course, is that harmonic currents flow exactly equally in both directions -- they're sine waves, after all! And harmonic voltages have exactly the same problem. That leaves harmonic phase angles.
We developed an entirely new harmonics instrument that can make in-situ
ultra-precise phase-angle measurements. (It's a research instrument, and we have no plans to produce it.) Bill Moncrief led an effort to use this instrument to make measurements at locations where the direction to harmonic sources is known -- in France, Canada, and the U.S. -- and Mack Grady led the effort to analyze the resulting data.
The results of the project are proprietary to CEATI and the world-wide utilities that funded the project, but may be published at some point in the future. Meanwhile, if you would like to become a funding member of CEATI
and possibly gain access to this research, or other worthwhile projects, I suggest you contact Alex Mogilevsky
PSL's Matthew Muh developed an ultra-precise harmonic-direction instrument for a CEATI research project.
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CIGRE-CIRED work on Power Quality - economics, voltage sag immunity
CIGRE and CIRED provide some of the best technical reports on power quality by gathering together the best experts in the world to provide definitive technical information. There are now two Joint Working Groups that I think are especially important: JWG C4.107, under the leadership of JL. Gutierrez Iglesias, is working on the economics of power quality, and JWG C4.110, under the leadership of Math Bollen of Sweden, is working on voltage dip immunity.
These are typical CIGRE/CIRED working groups, with experts from Australia, Japan, Canada, U.S., France, Germany, England, Scotland, Spain, Portugal, and Croatia.
Both groups met recently in San Francisco, hosted by Power Standards Lab. To complement the vigorous theoretical work, the Working Groups also visited the huge NUMMI automobile factory, the Stanford Linear Accelerator, and the California redwood forest.
If you are interested in voltage dip immunity, I recommend you follow the work of JWG C4.110 at their web site
(not all of it is public).
If you are interested in the economic impact of power quality, I recommend you follow the JWG C4.107 work at their web site
(again, not all of it is public).
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Useful power quality Guidebook - Tenaga (Malaysia)
Many utilities around the world have written excellent guides on power quality for their commercial and industrial customers.
Recently, I was especially impressed with the Power Quality guidebook, subtitled "Voltage Sag Solutions for Industrial Customers", produced by Tenaga Nasional Berhad in Malaysia.
Authored by Mohamed Fuad Faisal, it's an excellent 80-page guide - concise, accurate, up-to-date, and -- my favorite part -- nicely written in English. I don't know if it is readily available to everyone, but you might try sending an e-mail request to Mohamed Fuad Faisal
, Senior Technical Expert (Power Quality & EE), Engineering Services, Engineering Department, Distribution Division TNB.
Standards update - power quality
(power quality measurement methods) - Edition 2 is about to become official. Most of the changes from Edition 1 simply remove ambiguities, but one significant change is that Class A instruments no longer need to measure 200% of nominal voltage - now it's just 150%. The most recent meeting was in Paris. I'm grateful for all of the hard work by the Experts in my TC77A Working Group 9.
(voltage dip immunity, equipment rated at more than 16 amps per phase) - Under Claudia Imposimato's leadership, I'm working on Amendment 1. A number of small changes and corrections; a significant change is that the 1/2-cycle dip has been eliminated. It caused big saturation problems when testing transformer-based devices, and doesn't appear to have much benefit. We've received advice from CIGRE-CIRED JWG C4.110 regarding rise-time and fall-time, and those parameters may be revised. The most recent meeting was in Lisbon, Portugal.
TC85 Working Group 20
, under the leadership of Franck Gruffaz, has begun work on an IEC product standard for power quality measuring devices. Founded on the measurement methods in IEC 61000-4-30
, this new standard will emphasize instrument requirements -- including test requirements -- as opposed to measurement methods. This should be a useful standard. From my experience, there are too many instruments that claim to comply with Class A of 61000-4-30
that probably don't. A test standard will help. The most recent meeting was in the U.S., and the next meeting will be in China.
Power quality discussions in China
A couple of months ago, I gave the keynote speech at the 4th International Power Quality Conference in Yangzhou, China, and took the opportunity to visit and discuss power quality with a number of companies in China, including Bao Steel, Shanghai Power, TetraPak, and AMEC. (Even more recently, I had the pleasure of finally meeting Chen Bo, the Secretary General of China's National Standardization Committee for Electrical Measuring Instruments.)
Although I've been working on power quality in China for many years, I sense an acceleration: Everywhere in China you can see tremendous investment in infrastructure, including the power grid. China has the fastest growth in the world in almost every measure of electric power, and there's tremendous interest in how to optimally couple high tech equipment to this rapidly expanding grid.
For anybody interested in long-term power quality developments, China is a fascinating place, and a great opportunity. It's a friendly country (and it has great food, too). Like most countries, as a foreigner it's very important to learn enough to be polite, and we definitely need local guidance. Long-term personal relationships are important. But even if you don't have them today, it's never too late to start forming them!
Upcoming Power Quality seminars and discussions
Here's the general outline of most of my power quality seminars: McEachern Seminar Outline
. If you would like to arrange a seminar, please let me know
- San Francisco, USA - 15 July - Talk on about energy and carbon footprint, industrial equipment
- Pittsburgh, USA - 21-24 July - IEEE Power Engineering Society meeting
- Cleveland, USA 4-6 August - PQA Conference
- Tokyo JAPAN - 18-20 August - Private meetings and seminars
- Bangkok THAILAND - 21-22 August - PQ Synergy conference
- Brussels BELGIUM - 1-2 September - CIGRE-CIRED
- Zug SWITZERLAND - 3 September - private meeting
- Budapest HUNGARY - 10-12 September - conference
- Dublin IRELAND 16-18 September - CIGRE-CIRED
- Texas USA (Austin) - 21-23 October - ISMI conference
- Atlanta USA - 5-6 November - Conference
- Jakarta INDONESIA - 12-14 November - PLN National Power Quality Seminar
- Hyderabad INDIA - 17-19 November - Power conference, keynote - TENCON '08
- Nuremburg GERMANY - 1-3 December - IEC TC85
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