We'll be repeating this popular annual seminar in Boston on December 14, Austin on January 25, and Portland on February 23.
Seminar information: www.powerstandards.com/Seminar - Brochure.pdf
Alameda registration form: www.powerstandards.com/Seminar - Registration Form - Alameda.pdf
San Diego registration form: www.powerstandards.com/Seminar - Registration Form - San Diego.pdf
-------- FREE Power Quality Teaching Toy program - latest update -------------
I hope you will try my Power Quality Teaching Toy Rev 3.0.3. It's a great tool for engineers and students who want to develop an intuitive understanding of power flow, harmonics, flicker, voltage sags, and more.
English - Deutsch - Espaol - Franais - Portugus - Svenska - Romna.
This Windows 95/98/XP program is FREE, so no support is available - sorry!
--------- SEMI F47 voltage sag standard - 5 year update ----------------------
We're doing the five-year update of the hugely successful SEMI F47 voltage sag immunity standard for the semiconductor industry. It seems likely that this standard will be simplified and clarified, and it will probably be brought into alignment with the new IEC 61000-4-11 Ed. 2 and 61000-4-34 standards, but the essential requirements will remain the same. This has been a very successful standard, technically and economically for the industry, so there's no drive to make major changes. But we'll probably be adding detailed pass-fail criteria for components and systems, and more detailed requirements for certificates and reports. I'm serving as the Secretary of the Task Force that is updating the standard. Please let me know if you have any questions.
-------- New (to me) causes of voltage sags in Brazil ------------------------
Last month, at an excellent power quality conference in Brazil, I learned about two new (to me!) causes of voltage sags: kites, and overripe falling mangos hitting distribution insulators. After 30 years looking at voltage sags, there's still always something new to learn. By the way, a new organization called the Brazilian Power Quality Society has just been formed - let me know if you would like to e-mail the founders.
---- Updated IEC 61000-4-30 (power quality measurement standard) --------------
The Working Group 9 experts of IEC Technical Committee 77A gathered from all over the world here at PSL in Alameda, California, two weeks ago, and spent two intense days working on Edition 1 of this standard. It looks like a Corrigendum will be issued soon, along with a Committee Draft of Edition 2. The new edition simplifies and clarifies some of the measurements, and adds significant information on power quality surveys. (The process for a new edition takes years to complete, so keep using Edition 1 of IEC 61000-4-30 with confidence.) The experts expressed particular concern that certain labs world-wide seem to be certifying instruments for Class A performance without really understanding the requirements. If you run into this problem, please let me know, and I will try to help.
------- Question - which end of a shield should be grounded? -----------------
There's general consensus that only one end of a cable shield should be attached to earth, to avoid ground loops. But which end? If the cable contains conductors that are carrying signals in both directions, it probably doesn't matter. But for cables which have clear "transmitter" and "receiver" ends, which end should be grounded? I don't know, and I've heard reasonable arguments for both ends. Please let me know if you have practical experience with this question.
------------ Three-phase sags using Industrial Power Corruptors---------------
Most voltage sag immunity standards are clear: you should test immunity with sags applied one phase at a time, or between one pair of phases at a time. But a few companies insist on testing with simultaneous sags on all three phases, so PSL has made this possible with standard Industrial Power Corruptors (http://www.PowerStandards.com/saggen.htm). You can upgrade any IPC to a higher current rating, and now you can also use any IPC to create a huge variety of simultaneous three-phase sags, just by renting a couple of slave IPC's. More information? www.PowerStandards.com/ThriplePhaseIPC.pdf
------------ New applications for tiny, low-cost power quality relay ---------
I continue to be pleasantly surprised by creative applications for our little power quality relay (it's a tiny, low-cost power quality monitor that detects sags, swells, high frequency impulses, and outages). We're seeing them used on everything from elevator controls, to automated traffic reporting systems, to industrial equipment. In most of the applications, the relays are simply used to detect and record disturbances, but some of the more advanced users have written software that automatically re-initializes their process whenever a severe power disturbance occurs - very clever!
------------------------- New equipment at PSL -------------------------------
Two interesting new pieces of equipment at PSL: Ed Winterberger has constructed a transportable harmonic load, switchable in 1 kW steps up to 50 kW, for characterizing transformer response to harmonic currents. And we have just installed a 3-phase arbitrary waveform generator, with 20 kVA output and up to 600 volts per phase. (Coming next month: 200-amp 3-phase services at every world-wide voltage, from 100V to 600V, and a variable frequency 3500-amp source for testing circuit breakers and contactors.)
In the next couple of months, I expect to be working on power quality issues in Japan, Korea, England, and possibly Italy - perhaps we'll meet somewhere. In any case, send me an e-mail if there's anything I can do for you.
With best wishes -
Power Standards Lab
1201 Marina Village Parkway #101
Alameda, CA 94501 USA