Even though the damage was not insignificant, other regional grids in Australia similarly affected by the same storm were able to ride it out with only a few short power interruptions affecting smaller areas and were back up to full service within a couple of hours of the weather clearing. In South Australia, however, it took between two and seven days to get everyone back online.
An inverter changes direct current electricity to AC by opening and closing switches between the power sources and the grid connection. The frequency of an inertial grid is a sine wave, and so what the inverter does is open and close its switches many times so that the on-off cycle of the electricity flowing through it approximates that sine wave; the more switches in an inverter, or the faster they are able to operate, the 'smoother' the resulting curve is.