1. GIC Analysis using PSS®E
Siemens Power Technologies International
GIC Analysis using PSS®E

2. NERC TPL-007-1
Title:
Transmission System Planned Performance for Geomagnetic Disturbance Events
Purpose:
Establish requirements for Transmission system planned performance during geomagnetic disturbance (GMD) events.
Applicable to:
Planning Coordinator
Transmission Planner
Transmission Owner
Generator Owner
with Facilities that include power transformer(s) with a high side, wye-grounded winding with terminal voltage greater than 200 kV.

3. NERC TPL-007-1 GMD Vulnerability Assessment Process
PSS®E
GIC Module
PSS®E Analysis:
Contingency QV PV

4. GMD Event Uniform Geoelectric Field E(t)
Ignores effects of local earth conductivity and local geomagnetic latitude
Non-uniform Geoelectric Field E(t)
Considers 1-D local earth conductivity models
Benchmark GMD Event E(t)
E = 8 V/km
Considers α, the scaling factor to account for local geomagnetic latitude, and β, the scaling factor to account for the local earth conductivity structure

5. Development of DC System Model
Power flow network data reduced to just resistance network with these modifications:
The transmission lines modeled as resistor in series with induced voltage. Line reactors / charging ignored.
Grounded two- and three-winding transformers modeled with their winding resistance to ground.
Grounded auto-transformers are modeled with their common and series winding resistance.
Grounded Bus shunts are modeled.
Equivalent station grounding resistance is modeled.

6. Required GIC Data GIC Data File
Data not found in PSS®E network files is provided in an external data file, *.gic
PSS®E provides template to create such a .gic data file for desired subsystem of the network

7. Required GIC Data Substations

8. Required GIC Data Transformers

9. Required GIC Data Shunts and Branches

10. Required GIC Data 1-D Earth Conductivity Model

11. How to run GIC Analysis in PSS®E?

12. PSS®E GIC Analysis Input and Output Options
Text
Report
GMD
Storm
Sub
System
Data
Defaults
GIC
Data
Calculation
Options
Output
Files
Electrojet
Chars.

13. PSS®E GIC Calculations
GMD Storm Scenario
PSS®E GIC Module
PSS®E GIC Data
PSS®E Power Flow Network
GICs,
Transformer Q Losses
PSS®E Power Flow Network with GIC Losses
AC Power flow studies
Contingency analysis
PV/QV analysis
Dynamic analysis

14. Contingency Analysis with Benchmark Event GMD Effect of Geoelectric Field Direction

15. Contingency Analysis with Uniform Field GMD Effect of Geoelectric Field Magnitude

16. QV Analysis with GMD

17. Bus Voltages with GMD

18. Substation and Branch GICs

19. PSS®E GIC Module Conclusion
Fully integrated in PSS®E
Uses standard PSS®E networks (.sav or .raw files)
No Sequence data required
Additional data required for GIC calculations supplied through external GIC data file
GIC data files can be prepared using interactive tools, GIC Python module and Excel or a text editor
Rich reporting and interactive diagrams
Present GIC results on Network maps

20. GMD Vulnerability Assessment Conclusion
The conversion of GIC flows in a transformer to reactive power losses is crucial to ascertain and quantify GMD effects on power system performance. It is important to note that having accurate K factors from transformer tests and specifications will determine the accuracy of these studies.
The earth conductivity models play a deterministic role in evaluating the GIC flow in the network.
For conservative power system performance evaluation under GMD events, it is necessary to determine the geo-electric field orientation that would result in maximum reactive power losses in transformers.

21. Thank you for your attention!
Krishnat Patil Senior Staff Engineer Siemens Industry, Inc. Siemens Power Technologies International State Street Schenectady, NY 12305
Phone: +1 (518)