Abstract: A system includes a plurality of switches. The plurality of switches includes a first switch connecting a first load in a plurality of loads to a power supply line. The power supply line is connected to a public utility power grid. The plurality of switches also includes a second switch connecting a second load in the plurality of loads to the power supply line. The system further includes a power measurement device configured to measure a power grid frequency at the power supply line. The system additionally includes a load control module configured to operate the second switch to disconnect the second load from the power supply line when the power grid frequency is lower than a predetermined frequency threshold.

Abstract: In one embodiment of the present invention, a bi-directional power converter is described. The converter comprises a first bi-directional DC-DC conversion device having a first plurality of bi-directional DC-DC converters, a plurality of power supply ports, each connected to at least one of the first plurality of bi-directional DC-DC converters, and a voltage medium capacitor, which is connected to each of the first plurality of bi-directional DC-DC converters and has a first voltage greater than a second voltage measured at each of the power supply ports. The converter further may comprise a third bi-directional DC-DC converter device, which is connected to the voltage medium capacitor and is connected to a voltage high capacitor. The converter also may comprise a bi-directional AC-DC conversion device, which bi-directional AC-DC conversion device is connected to the voltage high capacitor and at least one inductor, which is connected to a plurality of AC ports.