Power supply control

• US 10,447,073 B2
• Filed: 01/07/2013
• Issued: 10/15/2019
• Est. Priority Date: 01/07/2013
• Status: Active Grant

• Current Assignee: Schneider Electric IT Corporation (Schneider Electric SE)
• Original Assignee: Schneider Electric IT Corporation (Schneider Electric SE)
• Inventors: Chambon, Patrick
• Primary Examiner(s): Tan, Richard
• Application Number:
  US14/759,445
• Publication Number:
  US 20150340908A1
• Time in Patent Office: 2,472 Days
• Field of Search: 307 66
• CPC Class Codes: H02J 3/16 by adjustment of reactive power
• CPC Class Codes: H02J 3/18 Arrangements for adjusting, eliminating or compensating reactive power in networks for adjustment of voltage H02J3/16
• CPC Class Codes: H02J 7/0068 Battery or charger load switching, e.g. concurrent charging and load supply H02J7/0013 takes precedence
• CPC Class Codes: H02J 9/061 for DC powered loads
• CPC Class Codes: H02M 1/4208 Arrangements for improving power factor of AC input
• CPC Class Codes: Y02B 70/10 Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes
• CPC Class Codes: Y02E 40/30 Reactive power compensation

Abstract

An uninterruptible power supply includes an input to receive an input AC voltage from a power source, an input circuit coupled to the input and configured to provide power factor correction, and a controller coupled to the input circuit. The controller is configured to detect that a reactive current is generated by one or more loads coupled to the power source and the input, and based, at least in part, on the detected reactive current, adjust an operating characteristic of the input circuit.

Claims

1. An uninterruptible power supply, comprising:

an input to receive input AC power from a power source and configured to be coupled to one or more non-protected loads;

an output configured to be coupled to one or more protected loads;

an input circuit coupled to the input and configured to provide power factor correction and convert the input AC power into DC power;

a DC bus coupled to the input circuit;

an inverter coupled to the DC bus and configured to provide output AC power derived from the DC power to the output; and

a controller coupled to the input circuit and configured to;

monitor an input AC voltage at the input;

generate a reactive current reference by comparing the monitored input AC voltage to an input voltage reference; and

based, at least in part, on the reactive current reference, provide a reactive compensation current to the input to compensate for reactive power drawn by the one or more non-protected loads coupled to the input.

2. The uninterruptible power supply of claim 1, wherein the reactive compensation current is substantially equal to a current in phase opposition with a reactive current corresponding to the reactive power drawn by the one or more loads.

3. The uninterruptible power supply of claim 1, wherein the input circuit is configured to determine that the power source is an engine-generator.

4. The uninterruptible power supply of claim 1, wherein the controller is configured to provide the reactive compensation current by, at least in part, adjusting the power factor correction provided by the input circuit.

5. A method for controlling an uninterruptible power supply, the method comprising:

receiving, at an input configured to be coupled to one or more non-protected loads, input AC power from a power source;

providing, by an input circuit, power factor correction;

converting, by the input circuit, the input AC power into DC power;

converting, by an inverter, the DC power into output AC power;

providing the output AC power to one or more protected loads coupled to the inverter;

monitoring an input AC voltage at the input;

generating a reactive current reference by comparing the monitored input AC voltage to an input voltage reference; and

based, at least in part, on the reactive current reference, providing a reactive compensation current to the input to compensate for reactive power drawn by the one or more non-protected loads coupled to the input.

6. The method of claim 5, wherein generating the reactive compensation current comprises generating a current substantially equal to a current in phase opposition with a reactive current corresponding to the reactive power drawn by the one or more loads.

7. The method of claim 5, further comprising determining that the power source is an engine-generator.

8. The method of claim 5, wherein providing the reactive compensation current comprises adjusting the power factor correction provided by the input circuit.