Uninterruptible power supply circuit

An uninterruptible power supply circuit comprising an inverter circuit configured to be connected to a first AC power grid, said power supply circuit configured to:

• i. a first configuration for supplying power to the first AC power grid from a second AC power grid, wherein first configuration a power factor correction circuit is configured to be connected to the second AC power grid so as to deliver a DC voltage to the inverter circuit, said power factor correction circuit comprising an inductor (L1), and a first switch branch (B1) pertaining to the power factor correction circuit and the inverter circuit;
• and
• ii. a second configuration for supplying power to the first AC power grid from a DC voltage source, in which second configuration a DC-DC converter circuit is configured to be connected to the DC voltage source so as to deliver a DC voltage to the inverter circuit, said inductor (L1) moreover pertaining to said DC-DC converter circuit, said inverter circuit being configured to convert the DC voltage delivered by the power factor correction circuit into an AC voltage that is delivered to the first power grid,
• wherein the power factor correction circuit comprises a second switch branch (B2), the terminals of which are connected to the terminals of the first switch branch (B1), a first terminal of said inductor (L1) being connected to the midpoint of one of the first and second branches (B1, B2), the midpoint of the other branch forming a first input terminal of the power factor correction circuit and a second terminal of said inductor (L1) forming a second input terminal of the power factor correction circuit, said first and second terminals of the power factor correction circuit being configured to be connected to the second AC power grid,
• wherein the switch branch of the power factor corrector that is not connected to the inductor (L1) forms a branch of the inverter in the second configuration, the midpoint of this branch forming the second output terminal of the inverter circuit.