IEEE Power Engineering Society

Task Force on Light Flicker

Meeting Minutes

IEEE PES Summer Meeting, San Diego, CA

Tuesday, July 14, 1998
  1. Mark Halpin opened the meeting; there were 27 in attendance.
  2. Minutes from the Tampa Winter PES meeting were reviewed and approved as

amended by Tom Key.

  1. Mark deferred the Chairman's report till later when it will be given by Ken Sedziol
  2. Liaison Reports
    1. IEEE Standard 141(Red Book), Larry Conrad is the voltage consideration chapter chair.
    2. Illumination Society, no report. Warren Anderson volunteered to be liaison.
    3. IEC (61000-3-7, 4-15), Roger Bergeron: The Canadian proposal for 120V lamps was accepted by WG2 along with the addendum. Voltage situations (3-7) already approved. Hydro Quebec is in the process of developing software to help field engineers understand and apply the new flicker criteria. Roger is willing to make a presentation to the TF on the software. Work being done by Erich Gunther and the Interharmonics TF could impact future work done by our TF as higher frequency interharmonics contribute to flicker. Our TF and Erich's should work together in this area.
    4. UIE Working Group #2 on Power Quality, Tom Key: The WG met in Spain in March. Erich also attended. Doni Nastasi of PEAC in Chair of the WG. The document is close to approval and a copy can be obtained on the web site. Documents can be purchased through the UIE.
    5. CIGRE 36-05, Power Quality, Erich Gunther: Had a joint meeting with UIE as documented above.
  3. Old Business
    1. PAR for application guide "How to avoid flicker" (Action 9)

This topic generated a lot of discussion by those present. It was expressed that the duty of the TF was first to address flicker measurement and to follow that with assessment. Erich emphasized the need to develop an application guide as opposed to a standard. He also suggested that the guide could be divided into five different chapters or topics:

  1. How to measure flicker
  2. How to interpret the results of the measurements
  3. How to design systems to prevent problems
  4. Compatibility levels
  5. How to correct existing problems

Roger pointed out that the determination of flicker for different types of loads would be informative and that the IEC has a document from which information could be drawn. It was stated that European measurement levels are based on a standard impedance that may not be relevant in the US. Roger said that Canada has defined a network impedance that is half the European value. The target for the application guide would lean toward utility engineers. Finally, a motion was make to develop a PAR to develop an application guide for assessing flicker using IEC and UIE work and other pertinent documents. The motion was approved and coordination of the work was assigned to Mark. This process was assigned Action #28 since Action 9 didn't speak to the development of a PAR.

  1. The TF's paper will be presented this afternoon by Mark. The procedure for TF papers has changed and now they must be reviewed through the normal paper review process. (Action 20)
  2. Mark has checked into getting the TF's paper published in the Power Engineering Review Letters. A summary of the paper will be published. It is also possible to have the paper published in the IAS Standards Corner. There is approximately a three-month lead time to get the paper published here. (Action 21)
  3. A time slot for the '99 Summer meeting has been requested for the tutorial session. Those interested in helping with the tutorial and/or being presenters should meet with Mark for a few minutes after this meeting to discuss. (Action 26)
  1. New Business
    1. Those present reviewed the P1453 Draft 1. Some questions arose concerning formal agreement with the IEC to use their document. Larry could best answer these questions so discussion on that part of the topic was tabled until the next meeting. An introductory section on the history of light flicker would add to the understanding of P1453. Tom Key and Tom Blooming were assigned the task of collecting the history of flicker measurement from the development of the GE curve to present. They will enlist the aid of Ed Owen of GE. A completion date of Nov. 1st was agreed on. (Action 27) Many expressed a need to document the changes made to the IEC document as they are reflected in P1453. Also, all references to IEC documents should be changed to the appropriate IEEE document. Roger indicated that 75 samples/sec are needed going into the classified as opposed to the 50 samples/sec listed by the IEC. He suggested that a statement could be added to say that higher sampling might improve accuracy. By Nov. 1st send any comments to Mark so that the final draft can be presented at the Winter PES meeting.
    2. Ken presented a summary of the SC77A WG2 meeting in Paris that was attended by Larry. A copy is attached to the minutes. Tom Blooming brought up a valid point that a number of flicker related phenomenon are not properly reported using Pst. A question was asked concerning the choice of a 60W incandescent light bulb since other types and wattages may give different results. The point was made that something had to be used for the standard since all type and ratings couldn't be included in the standard.
    3. The TPAR to harmonize with the IEC was presented for approval. It was tabled until the next meeting pending input from Larry.
  2. Ken Sedziol from Cinergy made a presentation how Pst can be impacted by things other than load. He documented a case where voltage variations on his system caused by a passing thunderstorm caused a rise in the Pst values that were recorded. The conclusion was that some correlation between storms, dips, sags, etc, on the system must be accounted for when determining a customer's compliance. A plot of the Pst during the storm is attached.
  3. Milan Graovac of the University of Toronto presented a comparison of various flicker meters. This work will be the topic of a future paper.
  4. Larry submitted a list of question in his WG2 report, attached, that he requested the group to answer. Concise answers follow
    1. Yes, but more work is needed
    2. The TF needs to investigate further
    3. Dmax - yes. Ref. Imp. - ???
    4. By specifying details of meter filters, vendor freedom of design is removed. It is best to rely on the test procedure. It was suggested that a new test point a 40Hz be added. It is preferred to define the test procedure rather than the filter specification. Mombauer's paper has detailed meter specifications. Erich will supply a copy for the TF's web site (Action 29). Discussion also followed on the pros and cons of digital vs. analog meters. It was stated that there could be math problems with digital filters when taking real measurements even though the transfer functions used meet the specifications. Again, this could be addressed by further defining the test specifications.
  5. Summary of Action Items
    1. Nine new action items were assigned, see separate action item list.
  6. Next meeting, IEEE IAS Annual meeting, St. Louis, MO, on October 12, 1998.
  7. The meeting was adjourned at 11:28AM

Submitted by:

Reuben Burch

August 19, 1998