Patent ID: 6949843
Filing Date: 2005-09-27
Classification: H02J,Y02B,Y02E

Abstract:
1. A grid-connected power system having a back-up power source, comprising a DC/AC inverter providing an alternating current output compatible with the alternating current of a utility grid, said DC/AC inverter being electrically connected with the utility grid to supply said output to the utility grid when power from the utility grid is available to power a load, being disconnected from the utility grid when power from the utility grid is unavailable to power the load, and being electrically connected with a selected portion of the load to supply said output to the selected portion of the load when power from the utility grid is unavailable to power the load; a primary power source providing a direct current output having a first voltage supplied as input to said DC/AC inverter; a backup power source providing a direct current output having a second voltage, different than said first voltage; and a DC/DC converter for receiving said output of said back-up power source when said DC/AC inverter is electrically connected with the selected portion of the load, said DC/DC converter converting the voltage of said output of said back-up power source from said second voltage to said first voltage to provide a direct current output having said first voltage supplied from said DC/DC converter to said DC/AC inverter as needed to power the selected portion of the load.