Load control for partially increasing/decreasing power usage

• US 5,543,667 A
• Filed: 11/21/1994
• Issued: 08/06/1996
• Est. Priority Date: 12/29/1992
• Status: Expired due to Term

• Current Assignee: Honeywell Incorporated (Honeywell International Inc.)
• Original Assignee: Honeywell Incorporated (Honeywell International Inc.)
• Inventors: Culp, Charles H., Shavit, Gideon
• Primary Examiner(s): Wong, Peter S.
• Assistant Examiner(s): KRISHNAN, ADITYA
• Application Number:
  US08/342,665
• Time in Patent Office: 624 Days
• Field of Search: 307/39-41, 307/38, 364/492-493, 340/825.06-825.09, 379/102, 379/104, 379/105
• US Class Current: 307/39
• CPC Class Codes: H02J 2310/54 according to a pre-established time schedule
• 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

An add/shed load controller which will add/shed or increase/decrease the electrical usage of a load. A maximum decrease limit may be set for analog loads to insure that comfort is not overly affected due to load usage reductions.

Claims

1. A system for adjusting component loads to increase or decrease energy usage of a total load to maintain power consumption below a predetermined level operative at sequential time intervals, wherein each component load is assigned to at least one of multiple types of add/shed or increase/decrease routines, each routine controlling the addition, partial increase, shedding or partial decrease of said components loads, said system comprising:

a power meter connected to measure the power usage of each component load; and

processor means connected to the total load and connected to said power meter, said processor means determining how much and which of the component loads should be increased/decreased or add/shed to maintain power consumption below said predetermined level based on the add/shed or increase/decrease routine assigned to each load, said processor means adding, shedding, increasing and decreasing each load according to its assigned routine, and wherein said processor performs said addition, partial increase, partial decrease, or shedding of said components loads to accommodate said predetermined level at a given time interval.

2. The apparatus of claim 1, wherein:

said processor means includes memory means for storing a decrease limit for said total load, said processor means adapted to not exceed said decrease limit when decreasing the total load.

3. The apparatus of claim 2, wherein:

said processor means calculates a required power consumption reduction necessary to maintain power consumption below said predetermined value, said processor means decreasing total load to accomplish said power consumption reduction.

4. The apparatus of claim 3, further comprising:

a plurality of loads having on and off states connected to said processor means, said processor means adding/shedding said loads having on and off states along with the loads having multiple levels of energy usage that can be increased or decreased by said processor.

5. The apparatus of claim 4, wherein:

there are a plurality of loads having multiple levels of energy usage and said loads having on and off states are arranged in a queue within each of the add/shed routines, said processor means identifying groupings of at least two consecutive partial loads having multiple levels of energy usage within each queue, said processor equally decreasing energy usage for all loads having multiple levels of energy usage within a grouping.

6. The apparatus of claim 3, wherein:

there are a plurality of loads having multiple levels of energy usage each of which is associated with a comfort sensor which produces a comfort signal indicative of a comfort index value;

said processor means includes memory for storing a comfort fairness factor, said processor means comparing all of said comfort index values associated with the loads having multiple levels of energy usage within one of said routines, said processor means decreasing said loads having multiple levels of energy usage in order of greatest to least difference between said associated comfort index value and said comfort fairness value until said desired power consumption reduction is achieved.

7. The apparatus of claim 3, wherein:

there are a plurality of loads having multiple levels of energy usage at least one of which is a variable air volume controller having an adjustable air flow.

8. The apparatus of claim 7, wherein:

said memory stores a maximum air flow deviation for each of said variable air volume controllers, said processor means adjusting said adjustable air flow by no more than said maximum temperature deviation when partially decreasing load.

9. A system as set forth in claim 1 wherein said processor accommodation of said predetermined level considers the anticipated load at the next time interval.