Load control apparatus with peak reduction in aggregate behavior

• US 8,766,491 B2
• Filed: 09/15/2011
• Issued: 07/01/2014
• Est. Priority Date: 09/27/2010
• Status: Active Grant

• Current Assignee: Aclara Technologies LLC (Hubbell, Inc.)
• Original Assignee: Aclara Technologies LLC (Hubbell, Inc.)
• Inventors: Fleck, Christopher K.
• Primary Examiner(s): Deberadinis, Robert L.
• Application Number:
  US13/233,173
• Publication Number:
  US 20120074780A1
• Time in Patent Office: 1,020 Days
• Field of Search: 307/140
• US Class Current: 307/140
• 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 3/003 Load forecast, e.g. methods or systems for forecasting future load demand
• 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

Abstract

When load control is activated by a local or remote mechanism to control a load, the method and system use a usage profile of the load and one or more of (1) interval start times, (2) ON/OFF or OFF/ON cycling and (3) predefined periods during which load must not be allowed to run (e.g., dead zones) to determine when a particular piece of equipment is allowed to shed or run thereby reducing the probability of occurrence of cyclical and non-cyclical aggregate peaking of usage wherein cyclical peaking is manifested as an artifact of the local load control rules during a load control event.

Claims

1. A load control apparatus for use with an electrical distribution system by which a utility supplies electricity to one or more pieces of equipment at a plurality of utility'"'"'s customer'"'"'s location, each piece of equipment placing an electrical load on the system when it is operating, said load control apparatus for connection to the pieces of equipment for controlling the shedding of electrical load placed on the system by the respective pieces of equipment, said load control apparatus comprising:

a power sensor for connection to a piece of equipment and sensing when electricity is being supplied to the piece of equipment;

a load control logic device responsive to inputs from the sensor for determining a usage profile indicative of the electricity usage of the piece of equipment, said usage profile being characterized over successive periods of time comprising a total characterization; and

a load control switch for shutting OFF electricity to the piece of equipment, said load control switch controlled by the load control logic device;

wherein, during occurrence of a load control event in which load on the system must be shed, at least one of the following;

the load control logic device controls the switch to shed load as a function of the usage profile and as a function of a predefined subinterval for defining the beginning of the predetermined interval thereby providing for diversification in the aggregate load control behavior of the apparatus as compared to other apparatus having a different predefined subinterval for defining the beginning of the predetermined interval;

the load control logic device controls the switch to shed the load as a function of the usage profile and as a function of the order of the switch cycling; and

the load control logic device controls the switch to shed load as a function of the usage profile and as a function of at least one predefined period of time during which the load control switch shuts OFF electricity to the piece of equipment thereby allowing for reduction in potential peaking of loads, cyclical or non-cyclical, during the load control event, so that the shedding is insulated from changes in the load usage profile of the piece of equipment, and so that other pieces of equipment having at least one different predefined period of time for shutting OFF electricity would start shedding their loads at the at least one different period of time.

2. The apparatus of claim 1 wherein the load control logic controls the switch to shed the load as a function of the usage profile and as a function of the predefined subinterval for defining the beginning of the predetermined interval.

3. The apparatus of claim 1 wherein the load control logic controls the switch to shed the load as a function of the usage profile and as a function of the order of the switch cycling.

4. The apparatus of claim 1 wherein the load control logic controls the switch to shed the load as a function of the usage profile and as a function of the at least one predefined period of time during which the load control switch shuts OFF electricity the piece of equipment.

5. The apparatus of claim 1 wherein the load control logic controls the switch to shed the load as a function of the usage profile, as a function of the predefined subinterval for defining the beginning of the predetermined interval, and as a function of the order of the switch cycling.

6. The apparatus of claim 1 wherein the load control logic controls the switch to shed the load as a function of the usage profile, as a function of the predefined subinterval for defining the beginning of the predetermined interval and as a function of the at least one predefined period of time during which the load control switch shuts OFF electricity the piece of equipment.

7. The apparatus of claim 1 wherein the load control logic controls the switch to shed the load as a function of the usage profile, as a function of the order of the switch cycling and as a function of the at least one predefined period of time during which the load control switch shuts OFF electricity to the piece of equipment.

8. The apparatus of claim 1 wherein the load control logic controls the switch to shed the load as a function of the usage profile, as a function of the predefined subinterval for defining the beginning of the predetermined interval, as a function of the order of the switch cycling and as a function of the at least one predefined period of time during which the load control switch shuts OFF electricity the piece of equipment.

9. The apparatus of claim 2 wherein the predefined subinterval is defined by at least one of a number associated with the apparatus and a random number.

10. The apparatus of claim 2 wherein the predefined subinterval is defined by a serial number of the apparatus.

11. The apparatus of claim 3 wherein said load control logic determines whether to begin allowing load or begin shedding load at the start of the load control interval as a function of the actual sensed usage just prior to the start time.

12. The apparatus of claim 3 wherein the order of cycling is defined by at least one of a number associated with the apparatus and a random number.

13. The apparatus of claim 3 wherein the order of cycling is defined by a serial number of the apparatus.

14. The apparatus of claim 4 wherein the at least one predefined period is defined by a number associated with the apparatus.

15. The apparatus of claim 4 wherein the at least one predefined period is defined by a serial number of the apparatus.

16. A method executed by logic or a processor, said method for use with an electrical distribution system by which a utility supplies electricity to one or more pieces of equipment at a plurality of utility'"'"'s customer'"'"'s locations, each piece of equipment placing an electrical load on the system when it is operating, said method for controlling the shedding of electrical load placed on the system by the respective pieces of equipment, said method comprising:

sensing when electricity is being supplied to the piece of equipment;

determining a usage profile indicative of the electricity usage of the piece of equipment, said usage profile being characterized over successive periods of time comprising the total characterization; and

selectively shutting OFF electricity to the piece of equipment during occurrence of a load control event in which load on the system must be shed, in accordance with at least one of the following;

shedding the load as a function of the usage profile and as a function of a predefined subinterval for defining the beginning of the predetermined interval thereby providing for diversification in the aggregate load control behavior of the apparatus as compared to other apparatus having a different predefined subinterval for defining the beginning of the predetermined interval;

shedding the load as a function of the usage profile and as a function of the order of the switch cycling; and

shedding the load as a function of the usage profile and as a function of at least one predefined period of time during which the load control switch shuts OFF electricity the piece of equipment thereby allowing for reduction in potential peaking of loads, cyclical or non-cyclical, during the load control event, so that the shedding is insulated from changes in the load usage profile of the piece of equipment, and so that other pieces of equipment having at least one different predefined period of time for shutting off electricity would start shedding their loads at the at least one different period of time.

17. The method of claim 16 wherein shedding the load comprises shedding the load as a function of the usage profile and as a function of the predefined subinterval for defining the beginning of the predetermined interval.

18. The method of claim 16 wherein shedding the load comprises shedding the load as a function of the usage profile and as a function of the order of the switch cycling.

19. The method of claim 16 wherein shedding the load comprises shedding the load as a function of the usage profile and as a function of the at least one predefined period of time during which the load control switch shuts OFF electricity the piece of equipment.

20. A system of a plurality of load control apparatus for use with an electrical distribution system by which a utility supplies electricity to one or more pieces of equipment at a plurality of utility'"'"'s customer'"'"'s locations, each piece of equipment placing an electrical load on the system when it is operating, said load control apparatus for connection to the pieces of equipment for controlling the shedding of electrical load placed on the system by the respective pieces of equipment, each said load control apparatus comprising:

a power sensor for connection to a piece of equipment and sensing when electricity is being supplied to the piece of equipment;

a load control logic device responsive to inputs from the sensor for determining a usage profile indicative of the electricity usage of the piece of equipment, said usage profile being characterized over successive periods of time comprising the total characterization; and

a load control switch for shutting OFF electricity to the piece of equipment, said load control switch controlled by the load control logic device;

wherein, during occurrence of a load control event in which load on the system must be shed, at least one of the following;

the load control logic device controls the switch to shed load as a function of the usage profile and as a function of at least one predefined subinterval used to determine the beginning of the predetermined interval and/or cycling order to minimize cyclical peaks in an aggregation of the apparatus of the system; and

the load control logic device controls the switch to shed load as a function of the usage profile and as a function of at least one predefined period of time during which the load control switch shuts OFF electricity to the piece of equipment to eliminate cyclical and non-cyclical peaks in an aggregation of the apparatus of the system.