Power shedding device

• US 5,534,734 A
• Filed: 12/09/1993
• Issued: 07/09/1996
• Est. Priority Date: 12/09/1993
• Status: Expired due to Term

• Current Assignee: American Power Conversion Corporation (Schneider Electric SE)
• Original Assignee: Compusci Incorporated
• Inventors: McNally, John M., Pugh, William C.
• Primary Examiner(s): Shoop, Jr., William M.
• Assistant Examiner(s): PALADINI, ALBERT WILLIAM
• Application Number:
  US08/164,160
• Time in Patent Office: 943 Days
• Field of Search: 307/38, 307/39, 307/40, 307/66, 364/273.1, 364/278.2, 364/273.3, 364/273.4, 364/273.5, 364/492
• US Class Current: 307/38
• CPC Class Codes: H02J 2310/60 Limiting power consumption in the network or in one section of the network, e.g. load shedding or peak shaving
• CPC Class Codes: H02J 3/14 by switching loads on to, or off from, network, e.g. progressively balanced loading
• CPC Class Codes: H02J 9/062 for AC powered loads
• CPC Class Codes: Y02B 70/30 Systems integrating technologies related to power network operation and communication or information technologies for improving the carbon footprint of the management of residential or tertiary loads, i.e. smart grids as climate change mitigation technology in the buildings sector, including also the last stages of power distribution and the control, monitoring or operating management systems at local level
• CPC Class Codes: Y02B 70/3225 Demand response systems, e.g. load shedding, peak shaving
• CPC Class Codes: Y04S 20/222 Demand response systems, e.g. load shedding, peak shaving
• CPC Class Codes: Y04S 20/248 UPS systems or standby or emergency generators

Abstract

A power shedding device controls the application of power from an uninterruptible power supply (UPS). It includes circuitry for detecting an alarm signal indicative of a condition requiring the rationing of power from the UPS, and a plurality of power outlets for connection to a plurality of loads such as computers, printers, and other associated devices. A microprocessor controls the application of power to each power outlet pursuant to program control such that the application of power to a first power output is independent of the application of power to a second power output. Manually operable switches are provides for presetting shedding profiles for the power outlets during a shutdown procedure. The processor is responsive to receipt of an alarm signal to shed each power output in accordance with its corresponding manually preset shedding profile. A low UPS battery alarm results in an override of the shedding profiles if the remaining time to shutdown for an outlet exceeds a predetermined limit. The processor is responsive to alarms from the UPS as well as to an auxiliary alarm. The power shedding device may be used with existing UPS monitoring software without modification. Power outlets are also manually selectable or deselectable by the user if desired. In addition provision is made for power recycling of all power outlets regardless of when power returns.

Claims

1. A power shedding device for controlling the application of power from an uninterruptible power supply, comprising:

means for detecting an alarm signal indicative of a condition requiring the rationing of power from the uninterruptible power supply;

a plurality of power outputs adapted for connection to a plurality of loads;

means for controlling the application of power to each power output such that the application of power to a first power output is independent of the application of power to a second power output;

manually operable means for presetting shedding profiles for the power outputs;

said controlling means being responsive to receipt of the alarm signal to shed each power output in accordance with its corresponding manually preset shedding profile.

2. The power shedding device as set forth in claim 1 wherein the alarm detecting means includes means responsive to a plurality of distinct alarm signals.

3. The power shedding device as set forth in claim 2 wherein the alarm detecting means is responsive to at least three distinct alarm signals.

4. The power shedding device as set forth in claim 3 wherein the alarm signal detecting means is responsive to at least one alarm signal originating from a source other than the uninterruptible power supply.

5. The power shedding device as set forth in claim 1 wherein the shedding profile of at least one of the power outputs is manually presettable to times from zero seconds to at least one hour.

6. The power shedding device as set forth in claim 5 wherein the shedding profile of at least one of the power outputs is manually presettable to a time of at least two hours.

7. The power shedding device as set forth in claim 1 wherein the manually operable shedding profile presetting means includes a set of switches.

8. The power shedding device as set forth in claim 1 wherein the power shedding device has at least three power outputs.

9. The power shedding device as set forth in claim 1 wherein the controlling means is responsive to an alarm signal to shed the power outputs in accordance with the shedding profiles independent of any termination of a corresponding alarm condition before all the power outputs are shed.

10. The power shedding device as set forth in claim 1 further including manually operable means for manually overriding the shedding profile of at least one of the power outputs.

11. The power shedding device as set forth in claim 1 wherein the controlling means has at least two modes of operation, the modes of operation being selectable by a user, further including manually operable reset means for generating a reset signal, the controlling means in one of said modes of operation being responsive to an alarm signal to shed the power outputs in accordance with the corresponding shedding profiles and to maintain said power outputs shed until receipt of the reset signal.

12. The power shedding device as set forth in claim 1 further including a plurality of visual indicators corresponding to the power outputs for visually indicating to a human user whether the respective power outputs are connected to the uninterruptible power supply.

13. The power shedding device as set forth in claim 12 wherein the visual indicators are controlled by the controlling means to provide a visual indication of the imminent shedding of their respective power outputs.

14. The power shedding device as set forth in claim 1 further including audible alarm means for sounding an alarm prior to shedding of one of the power outputs.

15. The power shedding device as set forth in claim 1 wherein said uninterruptible power supply includes an alarm output connector for providing alarm signals from the uninterruptible power supply to any compatible external device, said power shedding device further including a plug compatible with said alarm output connector for supplying alarm signals from said connector to the alarm detecting means, further including a second connector secured to the power shedding device, said second connector being substantially the same in configuration as the alarm output connector of the uninterruptible power supply, said controlling means supplying output signals to the second connector corresponding to the signals received from the alarm output connector.

16. The power shedding device as set forth in claim 1 wherein the alarm detecting means includes means for detecting an alarm indicating imminent total power loss, said controlling means being responsive to the imminent total power loss alarm to override the manually preset shedding profiles for all power outputs having a remaining time to shutdown greater than a predetermined limit.

17. The power shedding device as set forth in claim 16 wherein the predetermined limit is no greater than two minutes.

18. The power shedding device as set forth in claim 1 further including means for generating a manually initiated power output selection signal, said controlling means being responsive to the manually initiated power output selection signal to apply power from the uninterruptible power supply only to those power outputs selected by the power output selection signal.

19. The power shedding device as set forth in claim 18 wherein the controlling means is responsive to the manually initiated power output selection signal to override any on-going power down sequences initiated by an alarm signal.

20. The power shedding device as set forth in claim 18 wherein the means for generating the manually initiated power output selection signal includes manually operable means for canceling said power output selection signal.