Acclimating to Space Weather on our Transmission Grid

1. Acclimating to Space Weather on our Transmission Grid Don Watkins dswatkins@BPA.gov

2. Objectives • Assure awareness GeoMagnetic Disturbances • Awareness of FERC’s Plans for GMD (standards) • To understand Additional Required Simulation and Analysis Requirements

3. Coronal Mass Ejections What is a Geomagnetic Disturbance?

4. The Physics: Geomagnetic Disturbances And the earth impact….

5. Induced GIC Flow from Electric Field And Then Into the Euipment

6. GIC Impacts on Transformer Reactive And What Ensues John Kappenman, Geomagnetic Storms and Their Impacts on the U.S. Power Grid, Metatech Corporation Meta-R-319 p 20

7. Harmonic Current • Transformers become significant sources of harmonic current during GMDs • Shunt Capacitors and Filters can become overloaded • Protection Systems can be vulnerable to harmonic distortion Harmonic

8. Thermal Stress from Half Cycle Saturation And… • Thermal models are needed to know if a transformer is operating beyond thermal capability, and work is underway to develop models that translate GIC winding current to a hot spot temperature.

9. GMD Scenarios • While I believe many believe that significant destructive failure of EHV Transformers is unlikely, based on the construction and modes of failures, there is is at least anecdotal instances of Tx failures seeming correlated to GIC.

10. Doomsday GMD Scenario An Alternate scenario “Linked to the celestial spectacle are enormous fluctuations of the magnetic field in Earth's magnetosphere, which are causing immense flows of electric current in the upper atmosphere over much of the planet. Those huge currents disturb Earth's normally quiescent magnetic field, which in turn induces surges of current in electrical, telecommunications, and other networks across entire continents. Streetlights flicker out; electricity is lost. A massive planetary blackout has occurred, leaving vast swaths of North and South America, Europe, Australia, and Asia without power. Within a few months, the crisis has deepened. In many areas, food shortages are rampant, drinking water has become a precious commodity, and patients in need of blood transfusions, insulin, or critical prescription drugs die waiting. Normal commerce has ground to a halt, replaced by black markets and violent crime. As fatalities climb into the millions, the fabric of society starts to unravel.”

11. These are the issues • FERC closely monitored and was concerned that we would assess each of our Systems’ vulnerabilities: • extreme reactive draw During a high level GMD • impacts of high temperatures and risk to EHV Transformers.. (do you know how to do this?)

12. Thermal Stress from Half Cycle Saturation How will you Simulate and and Analize this in your Transformers? • Thermal models are needed to know if a transformer is operating beyond thermal capability, and work is underway to develop models that translate GIC winding current to a hot spot temperature.

13. The Response had has already been determined (Order No. 779, 143 FERC ) • In Order No. 779, the Commission directed NERC, pursuant to FPA section 215(d)(5), to develop and submit for approval proposed Reliability Standards that address the impact of GMDs on the reliable operation of the Bulk-Power System. The Commission based its directive on the potentially severe, wide-spread impact on the reliable operation of the Bulk-Power System that can be caused by GMD events and the absence of existing Reliability Standards to address GMD events. Order No. 779, 143 FERC ¶ 61,147 at P 3.

14. FERC Stage 1 • In the first stage, the Commission directed NERC to submit, within six months of the effective date of Order No. 779, one or more Reliability Standards (First Stage GMD Reliability Standards) that require owners and operators of the Bulk-Power System to develop and implement operational procedures to mitigate the effects of GMDs consistent with the reliable operation of the Bulk-Power System. • In the second stage, the Commission directed NERC to submit, within 18 months Id. P 2.

15. FERC Stage 2 • Standard(s) that require owners and operators of the Bulk-Power System to conduct initial and on-going assessments of the potential impact of benchmark events on Bulk-Power System equipment and the Bulk-Power System as a whole.

16. FERC Stage 2 cont. • If assessments identify potential impacts from benchmark GMD events, the Reliability Standards should require owners and operators to develop and implement a plan to protect against instability, uncontrolled separation, or cascading failures of the Bulk-Power System, caused by damage to critical or vulnerable Bulk-Power System equipment, or otherwise, as a result of a benchmark GMD event. (Please do your own research!)

17. Brief example of Sim and Analysis 1 V/km 3.78 V/km

18. An issue • In this Example it was difficult to get the highly significant transformer neutral lead resistances for system transformers. A number supplied but more did not. • We will need high cooperation in gaining such data.

19. How will this affect the WECC? • Will need data such as: • Accurate ground resistivity (USGS has accurate ground resistivity for much of the west (NW?) • GIC to heating transfer function • Benchmarks for simulation • Coordinated methdologies • Better monitoring of GIC and impacts for validation, etc

20. The Rub • You will be able to identify the amount of GIC flowing through your equipment but you likely don’t know the transfer function that will tell you the impact on the transformer. Most are unique and have varying impacts based on the specific design of a transformer because of where the magnetic flux goes that cannon by accommodated by the core.

21. Preparing for this • What needs to be added to our data bases (BCCS) to accommodate this? • What Program and Methodologies need to be developed to meet the FERC 1015 requirements?

22. Enough for now… • Questions? • Thoughts? • Advice?