Decentralized energy demand management

• US 7,373,222 B1
• Filed: 09/29/2003
• Issued: 05/13/2008
• Est. Priority Date: 09/29/2003
• Status: Active Grant

• Current Assignee: Rockwell Automation Technologies Incorporated (Allen-Bradley Co., Inc.)
• Original Assignee: Rockwell Automation Technologies Incorporated (Allen-Bradley Co., Inc.)
• Inventors: Lombardi, Steven A., Wright, Kevin P.
• Primary Examiner(s): Picard; Leo
• Assistant Examiner(s): KASENGE, CHARLES R
• Application Number:
  US10/673,825
• Time in Patent Office: 1,688 Days
• Field of Search: 700/20, 700/22, 700/28, 700/32, 700/33, 700/36, 700/286, 700/291, 700/292, 700/295, 700/297, 702/188, 307/29, 307/38, 307/115, 307/126, 705/412
• US Class Current: 700/295
• 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 3/144 Demand-response operation of the power transmission or distribution network
• 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

Abstract

A decentralized load management and control system and method are provided herein. A plurality of loads in a system are associated with a multitude of respective networked load controllers. If energy demand exceeds optimum limits in operation then the networked load controllers collaborate to determine which load(s) will be shed based on an optimization algorithm that considers, inter alia, variable load priority and business objectives. Additionally and/or alternatively, if the metered energy demand is less than optimum, the load controllers can determine which loads to reconnect again based at least upon load priority and business objectives.

Claims

1. A decentralized energy control and management system, comprising:

a plurality of loads associated with a system, wherein at least one subset of the plurality of loads is a member of a class, wherein members of the class are assigned to the class based upon a requirement that all members of the class must be connected to or shed from an energy supply in unison;

a plurality of networked load controllers associated with respective loads, wherein the load controllers cooperate to determine which load should be shed when the total system demand exceeds an optimum limit; and

a master controller that polls the plurality of networked load controllers to determine which loads are not connected to a power supply and are thereby inactive, determines load priorities associated with the inactive loads, finds the highest priority load among the inactive loads;

determines whether the highest priority load is a member of a class, and connects all members of the class to which the highest priority load is a member to the power supply if connecting the entire class would not bring total system demand above an optimum level, wherein total system demand is the total energy demand for all loads connected to the energy supply.

2. The system of claim 1, wherein loads are shed based on a priority associated with each load.

3. The system of claim 2, wherein priority is based at least in part on load function and context.

4. The system of claim 1, wherein the load controllers communicate over a local area network (LAN).

5. The system of claim 1, wherein the load controllers communicate wirelessly.

6. The system of claim 1, wherein the load controllers communicate over a wide area network (WAN).

7. The system of claim 1, further comprising a meter to measure parameters associated with energy consumed by the system.

8. The system of claim 7, wherein the measurements are transferred to and stored by a host computer.

9. A decentralized energy demand management system comprising:

a plurality of machines;

a multitude of networked load controllers associated with the plurality of machines, wherein the controllers collaborate and execute an optimization algorithm to determine how a load should be shed across the plurality of machines, wherein the load that is shed is a member of a class and all members of the class are also shed, wherein members of the class are assigned to the class based upon a requirement that all members of the class must be connected to or shed from an energy supply in unison; and

a master controller that polls the plurality of networked load controllers to determine which loads are not connected to a power supply and are thereby inactive, determines load priorities associated with the inactive loads, finds the highest priority load among the inactive loads;

determines whether the highest priority load is a member of a class, and connects all members of the class to which the highest priority load is a member to the power supply if connecting the entire class would not bring total system demand above an optimum level, wherein total system demand is the total energy demand for all loads connected to the energy supply.

10. The system of claim 9, further comprising a power supply.

11. The system of claim 9, wherein at least one of the plurality of machines is a variable speed motor such that load shedding with respect to the motor corresponds to reducing the power to the motor.

12. The system of claim 9, wherein the optimization algorithm includes parameters associated with the priority of a load.

13. The system of claim 12, wherein the optimization algorithm includes parameters associated with at least one business concern.

14. The system of claim 13, wherein the optimization algorithm includes parameters associated with the health of the machine.

15. The system of claim 9, wherein the optimization algorithm employs intelligent agents to act as proxies for the actual machines when determining the optimum load for each machine.

16. The system of claim 9, wherein the optimization algorithm utilizes a belief network.

17. The system of claim 9, wherein at least a subset of the machines are located physically remote from one another.

18. The system of claim 9, wherein the load controllers also determine which previously shed loads to reconnect.

19. A method of shedding and connecting loads to optimize system energy consumption comprising:

determining a maximum acceptable energy value;

metering the system to determine total system demand;

shedding loads according to a decision made by a plurality of networked load controllers so that the total system demand is not greater than the maximum acceptable energy value;

determining if a shed load is a member of a class;

shedding each member of the class if the shed load is a member, wherein members of the class are assigned to the class based upon a requirement that all members of the class must be connected to or shed from an energy supply in unison; and

polling a plurality of networked load controllers associated with loads to determine which loads are not connected to a power supply and are thereby inactive;

determining the load priorities associated with the inactive loads;

finding the highest priority load among the inactive loads;

determining whether the highest priority load is a member of a class; and

connecting all members of the class to which the highest priority load is a member to the power supply if connecting the entire class would not bring total system demand above an optimum level, wherein total system demand is the total energy demand for all loads connected to the energy supply.

20. The method of claim 19, wherein the decision to shed loads comprises:

determining a priority associated with active loads; and

shedding active loads of a higher priority before active loads of a lower priority.

21. The method of claim 20, wherein determining a priority includes considering load function and load context.

22. The method of claim 20, wherein the decision further comprises determining whether shedding of a particular load will interfere with a business objective and not shedding the particular load if such action would interfere with a business objective.

23. The method of claim 20, wherein the decision further comprises employing a utility based analysis.

24. An article of manufacturing comprising a computer usable medium having computer readable program code means thereon to perform a method for of claim 19.

25. A method of load shedding and load connecting comprising:

calculating a maximum acceptable energy consumption value;

determining total system demand, wherein total system demand is the total energy demand for all loads connected to the energy supply;

shedding particular machine loads organized under one or more classes, according to a decision by a plurality of networked load controllers associated with the machine loads based at least on a priority assigned to each machine in the system so as to bring the total system demand below the maximum acceptable energy consumption value;

shedding each member of a class to which the shed particular machine load belongs, wherein members of the class are assigned to the class based upon a requirement that all members of the class must be connected to or shed from an energy supply in unison; and

polling a plurality of networked load controllers associated with loads to determine which loads are not connected to a power supply and are thereby inactive;

determining the load priorities associated with the inactive loads;

finding the highest priority load among the inactive loads;

determining whether the highest priority load is a member of a class; and

connecting all members of the class to which the highest priority load is a member to the power supply if connecting the entire class would not bring total system demand above an optimum level, wherein total system demand is the total energy demand for all loads connected to the energy supply.

26. The method of claim 25, wherein shedding a load corresponds to reducing the power to a variable speed motor.

27. The method of claim 25, wherein the decision to shed a machine load is also based on at least one business concern.

28. The method of claim 27, wherein the decision to shed a machine load is also based on the health of the machine.

29. A computer readable medium having stored thereon computer executable instructions for carrying out the method of claim 25.

30. A method of connecting inactive loads to a power supply comprising:

polling a plurality of networked load controllers associated with loads to determine which loads are not connected to a power supply and are thereby inactive;

determining the load priorities associated with the inactive loads;

finding the highest priority load among the inactive loads;

determining whether the highest priority load is a member of a class; and

connecting all members of the class to which the highest priority load is a member to the power supply if connecting the entire class would not bring total system demand above an optimum level, wherein total system demand is the total energy demand for all loads connected to the energy supply.

31. The method of claim 30, wherein determining the load priority includes considering load function and load context.