Patent ID: 7948118

Claim:
An uninterruptible power supply comprising: at least one first input for connecting to a first AC voltage source, a power supply output for connecting to an electric load, a first converter for converting the AC voltage on the first input into a DC voltage, a bi-directional second converter for converting the DC voltage into AC voltage on the power supply output, a branching and/or selection circuit equipped with interrupting means for connecting a second input directly to the power supply output when operating in an economic mode wherein the first converter is shutdown, and control means comprising a set of units for use when operating in normal mode in which the second input is disconnected from the power supply output by opening the interrupting means of the branching and/or selection circuit, and the set of units comprises: a first voltage regulation unit equipped with an output for supplying a first reference current, and a second current regulation unit of the second converter equipped with a reference current input, and the control means comprises switching means for connecting the output of the first voltage regulation unit to the input of the second current regulation unit for regulating the current at said second input when operating in the economic mode.