Patent ID: 6630751
Filing Date: 2003-10-07
Classification: H02J,H02M,Y02B

Abstract:
An uninterruptible power supply for providing AC power to a load having a first 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 first capacitive element; first and second input nodes to receive DC power from the DC voltage source; a circuit operatively coupled to the first output node of the inverter, the circuit being configured to compare a value representative of load capacitance of the first capacitive element with a reference value to determine excessive load capacitance; 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.