SLIDE 1
atcllc.com
atcllc.com
2
Understanding Geomagnetically Induced Currents and Their Impact on - - PowerPoint PPT Presentation
Understanding Geomagnetically Induced Currents and Their Impact on - - PowerPoint PPT Presentation
Understanding Geomagnetically Induced Currents and Their Impact on the Power Grid: Morgan Substation Neutral Isolation Device (NID) Mike Londo American Transmission Co LLC atcllc.com Wisconsin Public Utility Institute June 2019 Quick
SLIDE 2
SLIDE 3
atcllc.com
Geomagnetic Induced Currents
EPRI Power Systems Dynamics Tutorial. EPRI, Palo Alto, CA: 2009. 1016042.
SLIDE 4
atcllc.com
SLIDE 5
atcllc.com
Possible Effects of GIC on ATC System and Equipment
- Transformer saturation
– Additional heating in transformers--likely – Transformer aging/failure--unlikely
- Additional VAR (Volts-Amps-Reactive) requirements
- n system
– Depressed voltages--likely – Voltage collapse on system--depends
- Harmonics
– Relay misoperation--unlikely – Generator heating--possible but small – Power quality problems--likely but small
SLIDE 6
atcllc.com
GIC Isolation Device at Morgan Substation
SLIDE 7
atcllc.com
7
Morgan Neutral Isolation Device
SLIDE 8
atcllc.com
8
Morgan Neutral Isolation Device cont’d
SLIDE 9
atcllc.com
Sequence of Operation
Normal Mode
SLIDE 10
atcllc.com
Sequence of Operation
Transitioning to GIC Isolation
SLIDE 11
atcllc.com
Sequence of Operation
In GIC Mode
SLIDE 12
atcllc.com
Sequence of Operation
Ground Fault in GIC Mode
SLIDE 13
atcllc.com
Sequence of Operation
Reset to Normal Mode
SLIDE 14
atcllc.com
Critical Development
The Transformation
- Fail Safe Resilience
– Spark Gap
- Non consumable
- Repeatable
- Inspected after 10 events
– Rogowski Coil (N-G path proof) Located on neutral bar heading to ground
SLIDE 15
atcllc.com
15
Morgan NID in “By-Pass” Mode
10kv spark gap
SLIDE 16
atcllc.com
16