Safe even during a solar storm
At a NERC conference, Siemens engineers provide proof for the
high degree of safety of Siemens power transformers
siemens.com/energy/transformers
During a conference of the North American Electric
Reliability Corporation’s (NERC) Geomagnetic Disturbance
Task Force (GMDTF) in Atlanta, the Siemens Global
Technology Center (GTC) offered proof of how Siemens
power transformers can withstand solar storms. The
engineers provided details of their studies on the impact
of geomagnetically induced currents (GICs). The GMDTF,
a specialist body within the nonprofit organization NERC,
deals with all issues relating to GICs and their effect on
the power transmission system.
Due to continuously changing solar activity, the density
of electrically charged particles in the earth’s ionosphere
and magnetosphere fluctuates as well. These particles
influence the earth’s magnetic field. In the event of a
so-called solar storm, the sun emits an especially large
amount of particles, which causes GICs – currents that
travel from the grounded neutral of a transformer
through the high-voltage windings into the transmission
lines. Power transformers are a strategic element in all
power transmission grids because they supply longdistance lines and complex integrated networks, so they
must withstand GICs as well as low-value direct currents.
At the NERC GMDTF conference, the Siemens engineers
presented their findings on the GIC capability of Siemens
Power Transformers and provided valid figures for the
transformers’ risk of failure in the event of a solar storm.
Suitable simulation models and special tests at the
high-voltage lab were used to perform the studies that
proved that thermal overload caused by GIC events is
noncritical for a wide range of power transformers.
This is due to the long time constants of the stressed
components in relation to the short duration of the
event. Siemens can thus provide transmission system
operators with transformers that are sufficiently
protected against the dangers caused by GICs.
According to the simulation results, the temperature rise
in the transformers is not critical.
Siemens AG
Energy Sector
Power Transmission Division
Transformators
Martin Stoessl
martin.stoessl@siemens.com
Publisher and copyright 2014:
Siemens AG
Energy Sector
Freyeslebenstrasse 1
91058 Erlangen, Germany
Answers for energy.