Local power consumption load control

• US 7,606,639 B2
• Filed: 09/06/2006
• Issued: 10/20/2009
• Est. Priority Date: 09/07/2005
• Status: Active Grant

• Current Assignee: Itron, Inc.
• Original Assignee: Comverge Incorporated (Itron, Inc.)
• Inventors: Miyaji, Wendell M.
• Primary Examiner(s): DeCady; Albert
• Assistant Examiner(s): Garland; Steven R
• Application Number:
  US11/470,534
• Publication Number:
  US 20070129850A1
• Time in Patent Office: 1,140 Days
• Field of Search: 700/295, 700/296, 307/39, 307/31, 315/291, 713/300, 713/320
• US Class Current: 700/296
• CPC Class Codes: G01R 22/063 related to remote communication
• CPC Class Codes: H02J 2310/14 The load or loads being home appliances
• CPC Class Codes: H02J 3/14 by switching loads on to, or off from, network, e.g. progressively balanced loading
• 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 20/242 Home appliances
• CPC Class Codes: Y04S 20/244 the home appliances being or involving heating ventilating and air conditioning [HVAC] units

Abstract

A method and system for curtailing energy consumption of an appliance, such as an air conditioning compressor or heat pump, is provided. A control unit stores information relating to the load, which may include a connected load value, such as a power consumption value or efficiency rating. The control unit then monitors the appliance to determine when the appliance is calling for energy. Upon receiving an energy reduction value from a remote source, the control unit then calculates a permitted run time from the energy reduction value and the connected load value. The control unit, through a switch, then permits the appliance to be operable only for the permitted run time so as to reduce power consumption by a predetermined amount.

Claims

1. A method for reducing energy consumption of an appliance, the method comprising the steps of:

providing an appliance actuation sensor configured to detect when the appliance is operational;

monitoring the appliance actuation sensor for a predetermined monitoring period to detect a fractional run time, wherein the fractional run time comprises a fraction of a predetermined period during which the appliance is calling for energy;

receiving a power reduction factor, the power reduction factor comprising a number of watts of consumption to be curtailed by the appliance during a predetermined period;

obtaining a connected load value corresponding to the appliance;

calculating an allowed energy consumption value from the fractional run time, the connected load value, and the power reduction factor;

calculating an allowed run time responsive to the allowed energy consumption that ensures a reduction of consumption by the appliance of at least the number of watts of consumption to be curtailed during the predetermined period; and

permitting the appliance to be operational in accordance with the allowed run time.

2. The method of claim 1, further comprising the step of calculating the allowed run time comprises the step of multiplying the fractional run time with the connected load value.

3. The method of claim 2, wherein the step of calculating the allowed run time further comprises the step of reducing a power consumption value by the power reduction factor.

4. The method of claim 3, wherein the step of reducing the power consumption value comprises subtracting the power reduction factor from the power consumption value.

5. The method of claim 4, wherein the step of calculating the allowed run time further comprises dividing a difference between the power reduction factor and the power consumption value by the connected load value.

6. The method of claim 5, wherein the step of calculating the allowed run time further comprises rounding the allowed run time by a predetermined percentage.

7. The method of claim 1, further comprising the step of receiving the power reduction value from a remote source.

8. The method of claim 7, wherein the remote source comprises a wireless transmitter.

9. The method of claim 1, wherein the step of permitting the appliance to be operational in accordance with the allowed run time comprises:

permitting the appliance to be operational for the allowed run time; and

prohibiting the appliance from being operational for a difference between the predetermined monitoring period and the allowed run time.

10. The method of claim 1, wherein when the allowed run time is below a predetermined minimum allowed run time, the method further comprises the step of setting the allowed run time to a default value.

11. The method of claim 1, wherein the power reduction factor comprises a power reduction profile.

12. the method of claim 11, wherein the power reduction profile comprises a series of power reduction values intended for implementation at predetermined time intervals, wherein each power reduction value comprises a number of watts of consumption by the appliance to be reduced during its corresponding predetermined time interval.

13. A system for reducing energy consumption of an appliance, the system comprising:

a control unit having a current sense transformer suitable for coupling serially with a control wire disposed between a control switch and an appliance;

a detection module configured to detect from the current sense transformer when the control wire is active;

a memory coupled with the control unit, the memory having a connected load value stored therein;

a receiver coupled with the control unit configured to receive a power reduction factor from a remote source, wherein the power reduction factor comprises a number of watts of consumption to be curtailed by the appliance during a predetermined period;

a processor configured to determine a fractional run time, wherein the fractional run time comprises a fraction of a predetermined period during which the appliance is calling for power, by monitoring the detection module, and to calculate an allowed run time from the fractional run time and the power reduction factor, the allowed run ensuring a reduction of consumption by the appliance of at least the number of watts of consumption to be curtailed during the predetermined period; and

a switch, operable by the processor and coupled to the appliance, wherein the processor is configured to actuate the switch so as to permit the appliance to be operational in accordance with the allowed run time.

14. The system of claim 13, wherein the appliance is one of an air conditioning compressor, a heat pump, or a furnace.

15. The system of claim 13, wherein the receiver comprises a wireless receiver.

16. The system of claim 13, wherein the control unit further comprises a local receiver configured to receive the connected load value.

17. The system of claim 16, wherein the local receiver comprises a device selected from the group consisting of an infrared receiver, an optic receiver, a fiber optic receiver, a radio frequency receiver, and a wired receiver.

18. The system of claim 13, wherein the receiver comprises a device selected from the group consisting of a radio frequency receiver and a power line carrier receiver.

19. The system of claim 13, wherein the switch is coupled serially with the control wire.