US 2001/0033505 A1 · Method and apparatus for converting a DC voltage to an AC voltage

Abstract

Embodiments of the present invention are directed to an uninterruptible power supply for providing AC power to a load. In embodiments of the present invention, the uninterruptible power supply includes an input to receive AC power from an AC power source, an output that provides AC power, a DC voltage source that provides DC power, the DC voltage source having an energy storage device, an inverter operatively coupled to the DC voltage source to receive DC power and to provide AC power. The inverter includes first and second output nodes to provide AC power to the load, first and second input nodes to receive DC power from the DC voltage source, a resonant element having a first terminal and a second terminal, the second terminal being electrically coupled to the first output node, a first switch electrically coupled between the first terminal of the resonant element and the first input node, wherein during a first time period, the first switch is controlled to allow an electrical current path to connect the resonant element to the capacitive element, an electrical current of the path storing energy in the resonant element and charging the capacitive element to a first voltage level, and during a second time period, the first switch is controlled to block the current path to cause the stored energy in the resonant element to further charge the capacitive element to a second voltage level during the second time period. The uninterruptible power supply further includes a transfer switch constructed and arranged to select one of the AC power source and the DC voltage source as an output power source for the uninterruptible power supply.

Claims22

Dependent claims

An uninterruptible power supply for providing AC power to a load having a capacitive element, the uninterruptible power supply comprising:

an input to receive AC power from an AC power source;
an output that provides AC power;
a DC voltage source that provides DC power, the DC voltage source having an energy storage device;
an inverter operatively coupled to the DC voltage source to receive DC power and to provide AC power, the inverter including:
first and second output nodes to provide AC power to the load having the capacitive element;
first and second input nodes to receive DC power from the DC voltage source;
a resonant element having a first terminal and a second terminal, the second terminal being electrically coupled to the first output node;
a first switch electrically coupled between the first terminal of the resonant element and the first input node, wherein during a first time period, the first switch is selected to enable an electrical current path from the resonant element to the capacitive element, an electrical current of the path storing energy in the resonant element and charging the capacitive element to a first voltage level, and during a second time period, the first switch is selected to block the electrical current path to cause the stored energy in the resonant element to further charge the capacitive element to a second voltage level during the second time period;
a set of switches operatively coupled between the first and second output nodes and the first and second input nodes and controlled to generate AC power from the DC power;
and
a transfer switch constructed and arranged to select one of the AC power source and the DC voltage source as an output power source for the uninterruptible power supply.

8 more elements

Dependencies are inferred from the claim text.

Method and apparatus for converting a DC voltage to an AC voltage

Life of this patent

Method and apparatus for converting a DC voltage to an AC voltage

Life of this patent

Abstract

Claims22