Omar,

Oncor recommends working on one GIC system model at a time instead of both the peak and minimum.  Focusing on one model should speed up the development of the GIC data file and base case modifications.  This file will most likely work for the minimum case with no or little modification since it is a 2021 case.

Forbidding an entity from developing a custom earth model may contradict TPL-007-1.  The Manual could recommend against the use of custom models rather than prohibit the use.

We recommend additional discussion of modeling tertiary-connected shunt reactors.  Our investigation of autotransformers, at least Oncor’s standard design, indicates the tertiary winding is magnetically coupled to the common winding instead of being part of the common winding.  Being a magnetically connected delta winding would prevent the GICs from flowing through the grounded shunt reactor into the common winding.

Thanks,

Mike

Omar:

1.       I thought we added the 17SSWG_2021_MIN_Final_06292017 case so that entities should be submitting data for 2 cases now – both 17SSWG_2021_MIN_Final_06292017  and 17SSWG_2021_SUM1_Final_06292017?  I’m not seeing where this is communicated in any of the notes?  Are we not working on both cases simultaneously to have both complete by March 2018? If not, please communicate the schedule for working on the 17SSWG_2021_MIN_Final_06292017 case?

2.       I think this range should be changed and perhaps communicated in the Procedural Manual and an approximate range:

a.       From: Latitude Range: 20 to 36 degrees

b.      To: Latitude Range: 25 to 36 degrees

PGDTF,

Attached is the PGDTF GIC Face to Face Model Review Meeting Notes. Please review and comment as necessary.

Due to confidentiality of the data, this was a TSP only meeting. Once the Restricted PGDTF List is created, information such as this will be sent via that list. Thank you all for very productive meetings both at the PGDTF Business meeting on Thursday and the Face to Face meeting on Friday.

Best Regards,

Omar A. Urquidez, PhD, P.E.

Chairman Planning Geomagnetic Disturbance Task Force

CenterPoint Energy

Office: (713) 207-2344

Cell: (617) 504-8704

Email: [log in to unmask]

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