Load shedding control for cycled or variable load appliances

• US 20070021874A1
• Filed: 07/24/2006
• Published: 01/25/2007
• Est. Priority Date: 07/22/2005
• Status: Active Grant

• Current Assignee: Eaton Intelligent Power Limited (Eaton Corporation PLC.)
• Original Assignee: Cannon Technologies, Inc. (Eaton Corporation PLC.)
• Inventors: Rognli, Roger, Ahlsten, Brian
• Granted Patent: US 7,528,503 B2
• Time in Patent Office: Days
• US Class Current: 700/295
• CPC Class Codes: G06Q 30/0207 Discounts or incentives, e.g. coupons or rebates
• CPC Class Codes: H02J 2310/64 The condition being economic, e.g. tariff based load management
• CPC Class Codes: H02J 3/14 by switching loads on to, or off from, network, e.g. progressively balanced loading
• CPC Class Codes: Y02B 70/3225 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 50/10 Energy trading, including energy flowing from end-user application to grid
• CPC Class Codes: Y04S 50/14 Marketing, i.e. market research and analysis, surveying, promotions, advertising, buyer profiling, customer management or rewards

Abstract

Control of a variable output appliance of a small energy consumer participating in an electrical load shedding program. A baseline operating characteristic of the appliance is determined for ordinary operation (such as in an absence of any load shedding requirements). An amount by which to reduce output of the appliance is determined in accordance with the load shedding program. Operation of the appliance is controlled to achieve the output reduction in accordance with the load shedding. This approach enables providing incentive for the small energy consumer to participate in the load shedding program, the incentive being based on the amount by which output is reduced, thereby representing a reduction of actual energy consumption for that small energy consumer.

Claims

1. A method of controlling a cyclically-operating appliance of a small energy consumer participating in an electrical load shedding program, the method comprising:

monitoring an indicator of actual power consumed by the appliance during a plurality of output variations or cycles;

based on the monitoring, computing;

(a) a level of maximum power consumed by the appliance during at least one period of full output, and (b) an overall level of power consumed by the appliance over the plurality of output variations or cycles;

determining a baseline characteristic of actual energy consumption of the appliance;

operating the appliance according to a new operating regime that produces a target reduction in energy output in accordance with the load shedding program; and

providing an incentive for the small energy consumer based on the amount by which output is reduced such that the amount is representative of a reduction of actual energy consumption for that small energy consumer.

2. The method of claim 1, wherein the step of monitoring the indicator of actual power consumed includes monitoring the amount of current drawn by the appliance.

3. The method of claim 1, wherein the step of monitoring the indicator of actual power consumed includes sampling the indicator at intervals that are much shorter than a period of output variation or cycling.

4. The method of claim 1, wherein the step of computing the level of maximum power includes averaging a plurality of samples of the monitored power indicator taken during a period of sustained output.

5. The method of claim 1, wherein the step of computing the level of maximum power includes integrating a plurality of samples of the monitored power indicator taken during a plurality of periods of sustained output, and determining which of the periods corresponds to the full output.

6. The method of claim 1, wherein the step of computing the overall level of power includes integrating a plurality of samples of the monitored power indicator taken during a period of output varying or cycling.

7. The method of claim 1, wherein the step of determining the baseline characteristic of actual energy consumption includes representing the baseline characteristic in terms of a ratio or percentage of full output.

8. The method of claim 1, wherein the appliance is an air conditioning system having at least one compressor, and wherein the step of monitoring the indicator of actual power consumed by the air conditioning system includes measuring a current draw of only the at least one compressor.

9. The method of claim 1, wherein the step of determining the baseline characteristic of energy consumption of the appliance is based on a ratio of the overall power level to the maximum power level;

and

wherein the step of operating the appliance according to the new operating regime in accordance with the load shedding program includes determining an amount by which to reduce output of the appliance in accordance with the load shedding program in terms of a percentage of the baseline characteristic of actual energy consumption, and controlling the appliance to reduce its output accordingly.

10. The method of claim 1, wherein the step of determining the baseline characteristic of energy consumption of the appliance produces a level of power consumption by the appliance;

and

wherein the step of operating the appliance according to the new operating regime in accordance with the load shedding program includes determining a target limit of power consumption to be achieved, and controlling the appliance to meet the target level.

11. A method of fairly administering an electrical load shedding program among a plurality small energy consumers that each operate a variable or cycled output appliance that is subject to load shedding, the method comprising:

for each appliance;

monitoring an indicator of actual power consumed by the appliance during a plurality of output variations or cycles;

based on the monitoring, computing;

(a) a level of maximum power consumed by the appliance during at least one period of full output, and (b) an overall level of power consumed by the appliance over the plurality of output variations or cycles;

determining a baseline characteristic of actual energy consumption of the appliance based on a ratio of the overall power level to the maximum power level;

determining an amount by which to reduce output of each appliance in accordance with the load shedding program, wherein the amount is defined as either;

(a) a percentage of the baseline characteristic of actual energy consumption for that appliance, wherein the percentage is substantially the same for all appliances participating in the load shedding program;

or

(b) an amount of power by which consumption is to be reduced, wherein the amount of power is s substantially the same for all appliances participating in the load shedding program; and

providing incentive to the small energy consumer for the amount by which output is reduced such that the amount is representative of a reduction of actual energy consumption for that small energy consumer.

12. A method of controlling a variable output appliance of a small energy consumer participating in an electrical load shedding program, the method comprising:

determining a baseline operating characteristic of the appliance that would exist in an absence of any load shedding requirements;

determining an amount by which to reduce output of the appliance in accordance with the load shedding program;

controlling operation of the appliance to achieve the output reduction in accordance with the load shedding, wherein the controlling preferentially operates the appliance at a reduced output for longer durations to reduce a cycling frequency; and

providing an incentive for the small energy consumer based on the amount by which output is reduced such that the amount is representative of a reduction of actual energy consumption for that small energy consumer.

13. The method of claim 12, wherein the step of determining the amount by which to reduce the output of the appliance produces a value of a type selected from the group consisting of:

a ratio relative to the baseline characteristic, and a power consumption magnitude representing a power consumption reduction target.

14. The method of claim 12, wherein the step of determining the amount by which to reduce the output of the appliance produces the amount in terms of a ratio relative to the baseline characteristic.

15. The method of claim 12, wherein the step of determining the baseline operating characteristic includes making measurements of an indicator of actual power consumption of the appliance.

16. The method of claim 12, wherein the step of determining the baseline operating characteristic includes monitoring an appliance control signal.

17. A method of controlling a cyclically-operating or variable load appliance of a small energy consumer participating in an electrical load shedding program, the method comprising:

configuring a load control receiver (LCR) at the appliance such that the LCR is able to monitor and control operation of the appliance;

operating the LCR to;

receive a load reduction criterion that defines compliance with the load shedding program in terms of energy use;

monitor an indicator of actual power consumed by the appliance;

adjust operation of the appliance to satisfy the load reduction criterion; and

based on the monitored actual power, indicate an amount of load reduction achieved in terms of energy use; and

providing an incentive for the small energy consumer based on the amount of load reduction such that the amount is representative of a reduction of actual energy consumption for that small energy consumer.

18. The method of 17, wherein the step of receiving the load reduction criterion includes receiving at least one energy use variable selected from the group consisting of:

an amount of energy reduction over a defined time duration, a power consumption level integrated over a defined time duration, and a ratio of power consumption relative to a maximum output of the appliance.

19. A system for administering an electrical load shedding program for a plurality of small energy consumers that run cyclically-operating or variable load air conditioners, the system comprising:

a load control receiver (LCR) configured at each of the air conditioners, wherein each LCR includes;

a power sensing arrangement that monitors current draw by at least one compressor of each air conditioner;

a communications sub-system that receives load reduction criteria from a utility provider, the load reduction criteria defining compliance with the load shedding program in terms of energy use; and

a controller that supplies output signaling for selectively operating the at least one compressor based on the current draw and on the load reduction criteria, wherein the controller is configured to adjust an operation regime of the at least one compressor to produce an energy consumption profile that is in compliance with the load reduction criterion.

20. The system of claim 19, wherein the power sensing arrangement includes at least one current transformer coupled to at least one power conductor of the at least one compressor.

21. The system of claim 19, wherein the communication sub-system power sensing arrangement includes at least one current transformer coupled to at least one power conductor of the at least one compressor.