The induced EMF from a change in magnetic field strength (note it is a vector quantity so a change in direction also changes things), is the time rate of change in the net magnetic flux going through a closed circuit. Flux is area (normal vector) dotted with the field. So the area covered by a current loop determines the sensitivty to field changes. In the power grid on earth, dimensions are on the order or hundreds to a few thousand kilometers, so a small change in the magnetic field times a large area can generate a high voltage. The ISS is many times smaller, so induced voltages/currents should be orders of magnitude smaller. The real problem for the ISS is the ionizing radiation of the particles, either from the solar wind, or trapped in the earths geomagnetic field. A secondary issue is that the strength of the solar wind interaction determines the temperature and hence the rate of the pressure/density decline with altitude. During periods of high activity the pressure of the earths atmosphere that objects in low earth orbit encounter is higher, so drag forces and orbital lifetimes are affected.
