Transformer capability while under geomagnetic disturbances
Geomagnetic disturbances (GMD) due to solar activity can lead to geomagnetically induced currents (GIC) in power system networks. These geomagnetically induced current are quasi DC in nature 0.01Hz to 0.5Hz and have the effect of saturating the core of power transformer.
The saturation of the core due to these currents leads to increased magnetizing current peaks up to several time the nominal current of the unit. The high magnetizing currents significantly increase the reactive power demand of the transformers and high amounts of harmonic are injected into the power system.
Moreover, these high quasi-DC flux on the core and associated high magnetizing currents overheat transformer windings and clamping structure and increase overall losses.
IEEE has issued a Guide to establish the power transformer capabilities while under geomagnetic disturbances IEEE C57.163-2015 where guidelines are provided to evaluate the transformer design resilience to GIC events.
Given the relevance on the topic of GIC disturbances we have developed a methodology determine transformer capability in these conditions as per IEEE Std C57.163 and we can now provide this service.
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