Transmission Owners and Transmission Service Providers,
The ERCOT Board of Directors has approved PGRR046 (attached) which modifies the ERCOT Planning Guide to add the requirement for the ERCOT Staff, the Resource Entities and the TSPs to develop the Geomagnetically-Induced
Current (GIC) System Models required to perform the Geomagnetic Disturbance (GMD) vulnerability assessment required by the NERC GMD Planning Standard. The Reliability and Operations Subcommittee (ROS) formed the Planning Geomagnetic Disturbance Task Force
(PGDTF) to work with the ERCOT Staff to develop the GIC System Models and to perform the GMD vulnerability assessment. The ROS has approved the attached GIC System Model Procedure Manual which will be followed, along with the attached NERC GIC Application
Guide, to create the GIC System Models. The models are a direct current model, not an alternating current model like the power flow model, because the GICs are quasi direct currents. Following is an excerpt from the Procedure Manual that provides a general
description of the model. All TSPs are required to provide the data for its system to the ERCOT Staff, who, in conjunction with the PGDTF, will compile the transmission and generation data into the model for the ERCOT system. The data for the initial model
is due to the ERCOT Staff in December 2016 to provide adequate time for the ERCOT Staff and the PGDTF to complete development of the model and testing of the GIC software. Additional information concerning the PGDTF and the GMD planning activity can be found
on the PGDTF’s web page at http://www.ercot.com/committee/pgdtf. If you are not a member of the PGDTF, you can join at
http://lists.ercot.com/scripts/wa-ERCOT.exe?INDEX=&p=2.
1.1.1.
GIC
System
Model
– General
ERCOT
shall
provide
a workbook
to TSPs
for
the submission
of
data
for the
GIC System
Model.
TSPs
shall
provide
the GIC
System
Model
data
to ERCOT
using the
provided
workbook
as shown
in
Appendix
B by
the schedule
published
by the PGDTF.
For
the 200
kV
system
and
above,
actual
data
should
be used
for the
GIC
System
Model.
Typical
data
based
upon
actual
data or data converted from SSWG base case data
can
be
used
if
actual
data
is
not available.
For
the 69
kV and
138
kV systems,
actual
data may
be used
for the
GIC System
Model
to the
extent
possible.
Typical
data
based
upon
actual
data
can
be used
if
actual
data is
not available.
Default
data as
specified
by this
Procedure
Manual
or data converted from SSWG base case data can
be used
if actual
or typical data
is
not reasonably
available.
The
PGDTF
will
select
the latest
update
to the
SSWG
base cases,
updated
if required
to reflect
known and
significant
changes,
to be
used
as the
starting
base cases for
the GIC System
Model as
listed
below.
•
The
System
Peak
case
will
be represented
by the
SSWG
three
year
out Summer
Peak case.
•
The
Off-peak
case will
be represented
by the
three
year
out
SSWG
MIN case.
The next meeting of the PGDTF is scheduled for Wednesday September 28, 2016 at the Met Center in Austin. WebEx will be available for the meeting if you cannot attend in person. We will continue the discussions
on the data required for the GIC System Models and provide lessons learned so far in the development of the data.
Please contact me if you have any questions.
Thanks,
Michael Juricek, P.E.
Chairman Planning Geomagnetic Disturbance Task Force
Asset Planning Distribution and Transmission
Oncor Electric Delivery Co LLC
E-mail:
[log in to unmask]
Office: 214.743.6671
Mobile: 214.490.0748