ABSTRACT
Magnetic inrush currents in distributed photovoltaic grid transformers (DPV-GTs) can be as high as 10 to 20 times the nominal current. The solution uses a typical thermistor in series with the primary. This thermistor offers high resistance at the beginning of switching and limits the inrush current. After a short time, the thermistor resistance decreases to a low value due to self-heating and does not affect normal operation. Normally thermistors are rated up to 65 C for their operating current, and then a de-rating factor must be taken into account. During a solar storm, as the coronal mass ejection plasma cloud collides with the planet, large, transient, magnetic perturbations overlay and alters the normally stable magnetic field of Earth. These magnetic perturbations are referred to as a geomagnetic storm and can affect the planet for a period of a day or two.
