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27 Nov 2020, 12:37
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A space weather event can produce geomagnetically induced currents (GICs) that may be transmitted by surface-connected conductors such as the electric-power grid. When GICs enter the power grid, they act as direct current (DC) sources that flow alongside the normal alternating currents (AC) produced at power plants and transferred along power lines to electrical substations. Basic incompatibilities between DC and AC currents may interfere with the normal functioning and performance of Extra High Voltage (EHV) transformers. The interaction of GICs with these transformers can result in a number of physical effects that, if sufficiently large and not properly managed, may adversely impact the power system.
For example, GIC–transformer interactions can increase reactive power consumption, contributing to voltage instabilities and potentially leading to power outages. They can also cause interference that leads to the improper operation of protective relay equipment (e.g., static compensators) and/or the tripping offline and potentially damaging of generators. It is important to note that this impact pathway is the only one that has to-date been known to trigger space weather–related blackouts.
For example, GIC–transformer interactions can increase reactive power consumption, contributing to voltage instabilities and potentially leading to power outages. They can also cause interference that leads to the improper operation of protective relay equipment (e.g., static compensators) and/or the tripping offline and potentially damaging of generators. It is important to note that this impact pathway is the only one that has to-date been known to trigger space weather–related blackouts.
For each of the following, select Affected if the information provided supports the conclusion that the item could be negatively impacted by geomagnetically induced currents (GICs). Otherwise, select Not Affected.
| Affected | No discernible effect | |
| Communication satellites | ||
| Power generators | ||
| Static compensators |
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Official Answer
Communication satellites: No discernible effect
Power generators: Affected
Static compensators: Affected
27 Nov 2020, 12:37
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Official Solution:
Communication satellites
• Tab 1 explains how geomagnetically induced currents (GICs) affect ground-level electrical infrastructure, including transformers, relay equipment, and power lines. It does not mention satellites or any space-based systems. Therefore, there is no support for the idea that communication satellites are affected by GICs in this context. Not Affected.
Power generators
• Tab 1 states that geomagnetically induced currents can cause the tripping offline and potentially damaging of generators. This confirms that power generators can be negatively impacted by GICs. Affected.
Static compensators
• Tab 1 states that geomagnetically induced currents can interfere with the operation of protective relay equipment, and explicitly gives static compensators as an example. This confirms that static compensators can be negatively impacted by GICs. Affected.
Correct answer:
Communication satellites "No discernible effect"
Power generators "Affected"
Static compensators "Affected"
Bunuel
Communication satellites
• Tab 1 explains how geomagnetically induced currents (GICs) affect ground-level electrical infrastructure, including transformers, relay equipment, and power lines. It does not mention satellites or any space-based systems. Therefore, there is no support for the idea that communication satellites are affected by GICs in this context. Not Affected.
Power generators
• Tab 1 states that geomagnetically induced currents can cause the tripping offline and potentially damaging of generators. This confirms that power generators can be negatively impacted by GICs. Affected.
Static compensators
• Tab 1 states that geomagnetically induced currents can interfere with the operation of protective relay equipment, and explicitly gives static compensators as an example. This confirms that static compensators can be negatively impacted by GICs. Affected.
Correct answer:
Communication satellites "No discernible effect"
Power generators "Affected"
Static compensators "Affected"
