Ben,
The GIC flows posted are good evidence of localized impact of the different orientations because the max GIC for each transformer did not occur at the same orientation. Have you developed a
methodology for examining different GMD orientations that we can discuss at a PGDTF meeting?
Thanks,
Mike
From: Planning Geomagnetic Disturbance Task Force [mailto:[log in to unmask]]
On Behalf Of Richardson, Ben
Sent: Friday, August 10, 2018 9:27 AM
To: [log in to unmask]
Subject: FW: Why we should seriously consider examining losses based on more than 1 GMD orientation
***** EXTERNAL email. Please be cautious and evaluate before you click on links, open attachments, or provide credentials. *****
PGDTF:
The attached is FYI.
|
A. Benjamin Richardson, P.E.(Colorado) System Development – Transmission Planning 2705 West Lake Drive Taylor, TX 76574 O: 512-248-4505 | M:720-470-3643 |
From: Richardson, Ben
Sent: Tuesday, July 10, 2018 1:49 PM
To: Dylan Preas <[log in to unmask]>; Weatherly, Joe <[log in to unmask]>; Loyferman, Larisa M. <[log in to unmask]>;
Juricek, Michael <[log in to unmask]>
Cc: Borkar, Sandeep <[log in to unmask]>
Subject: Why we should seriously consider examining losses based on more than 1 GMD orientation
Team (feel free to pass this e-mail around):
Justification to examine more than 1 orientation:
1.
Please read (less than 1 page of reading) Section 3.3 of NERC GMD Planning Guide: https://www.nerc.com/comm/PC/Geomagnetic%20Disturbance%20Task%20Force%20GMDTF%202013/GMD%20Planning%20Guide_approved.pdf
2.
Notice the NERC time-series data for the benchmark event is provided with data points at 10 second intervals for a 30 hour event. Within most of those 10 second intervals the storm changes orientation significantly. For example from time point 56,590
seconds to 56,600 seconds, a 10 second interval, the storm changes orientation by 178 degrees. You can find this 10 second 30 hours Excel data on NERC’s website under Benchmark GMD Event in this location:
https://www.nerc.com/comm/PC/Pages/Geomagnetic-Disturbance-Task-Force-(GMDTF)-2013.aspx?View={2411fa34-593e-4b21-be7a-245dcb384c5d}&SortField=Date&SortDir=Desc
Conclusion. If we expect outages to produce multiple system topologies during a presumed 30 hour event, we are also likely to experience system reactive losses that are very different than system reactive losses that are produced by a
base case with all facilities in-service.
This is the point I was attempting to communicate yesterday during our discussion of Orientation 2 in the draft Vulnerability Assessment Scope. I walked away feeling that Mick Juricek understood this point clearly but not feeling like
others did. Whether you agree that we should examine losses for more than 1 orientation or not, I hope this will at least clarify why I am concerned.
|
A. Benjamin Richardson, P.E.(Colorado) Transmission and Interconnection Studies 2705 West Lake Drive Taylor, TX 76574 O: 512-248-4505 | M:720-470-3643 |
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