Load management control apparatus with improved duty cycle operation

• US 4,347,576 A
• Filed: 04/28/1980
• Issued: 08/31/1982
• Est. Priority Date: 04/28/1980
• Status: Expired due to Term

• Current Assignee: Honeywell Incorporated (Honeywell International Inc.)
• Original Assignee: Honeywell Incorporated (Honeywell International Inc.)
• Inventors: Kensinger, Robert A., Norman, Robert N.
• Primary Examiner(s): Wise, Edward J.
• Application Number:
  US06/144,495
• Time in Patent Office: 855 Days
• Field of Search: 364/492, 364/493, 364/200, 307/39, 307/35, 307/41, 307/52, 307/62
• US Class Current: 713/600
• 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

A load management control apparatus with an improved duty cycle operation has a programmed means to control the off time for a selected interval of time for several loads. The total percentage of off time of the loads being controlled is summed and the total integer is used by a sequential operational means to maintain that number of load off at all times even if loads which are off on demand limit control are included to make the number.

Claims

1. In a load management control apparatus comprising,

a plurality of switch means adapted to control individual loads for individual duty cycles of a predetermined off time for each operating time interval,

means connected to said switch means for programming the operation of said switch means to select a percentage off time and an operating time interval for certain of said switch means and thus its load,

means connected to said means for programming for determining the total percentage of off time of all the loads which are being duty cycled and rounding this number off to the closest whole number, and

control means connected to said means for programming for always maintaining the number of loads off the same as said whole number.

2. An improvement in a load management control apparatus having programmable means to duty cycle a plurality of loads in a sequential operation to turn off each load a selected predetermined percentage of the time interval selected for the operation of each load, the improvement comprising,

means to determine the percentage of off time of the time interval of each load which is being duty cycled,

means to determine an integer of the total of said percentage of off time of all of said loads being duty cycled, and

means to modify the sequential operation of said programmable means to maintain the number of loads, being duty cycled, in an off operation at any one time equal to said integer.

3. In a load management control apparatus comprising, a plurality of output means each adapted to control an individual load,

sequential operational means connected to said plurality of output means for selectively programming the operation of certain of said output means to turn off certain of said loads in a sequential operation for a predetermined percentage of a predetermined time interval of that load, depending on the particular duty cycle selected for that load,

means connected to said operational means for determining the total percentage of off time of the interval of each load of all the loads having a duty cycle program,

and

means for modifying the sequential operation of said sequential operational means to turn off at all times a number of loads equal to the closest integer of said total percentage.

4. The invention of claim 3 wherein,

temperature responsive means associated with certain of said output means and thus the loads,

said sequential operational means having means to program the off operation of certain of said output means depending on the temperature operation limits selected by said temperature responsive means associated with its load,

said means for modifying the sequential operation of said sequential operational means being operative with loads which are in said off condition by being duty cycled at said moment and loads which are in said off condition by a duty cycle operation depending on said temperature limits;

whereby,

upon the occurrence of a temperature change by said responsive means to change the duty cycle of any one load, said percentage of off time is changed to reflect the number of loads to be turned off at all times by said sequential operational means.

5. The invention of claim 3 wherein

said sequential operational means comprises,

timing means responsive to the operational elapsed time since the particular load interval was completed for each of said loads,

and means connected to said operational means including said timing means for each load to compare the elapsed time of all loads and sequence as the next load, the load having the longest elapse time.

6. The invention of claim 3 wherein,

means associated with any one of said plurality of output means to result in turning off that particular load provides for an input to said sequential operational means to choose which of said loads will be used in the consideration in the selection of the number of loads to be turned off at all times.

7. The invention of claim 3 comprising

operational condition responsive means connected to respond to the operational condition of each of said output means, and

means connecting said condition responsive means of each duty cycled load to said sequential operational means to prevent operation of any one output means to an on position until the selected off interval has expired.

8. The invention of claim 3 comprising,

time of day control apparatus for selectively turning certain switch means and thus its load off during selected time periods, and

means connecting said control apparatus to said operational means to remove said time of day loads from being used by said sequential operational means when said total percentage of off time of duty cycle loads is determined.

9. The invention of claim 3 comprising

demand limit control apparatus for selectively turning certain switch means and thus its load off during certain times in response to the total power demand of all of the loads, and

means connecting said control apparatus to said operational means to add said loads to be used by said sequential operational means as the number of loads equal to said integer.

10. The invention of claim 3 comprising

delay means connected to said means for modifying the sequential operation of said sequential operational means to delay a change in said number of loads turned off to match said integer when said integer changes.

11. The invention of claim 10 comprising means connected to

said delay means to only allow for a change in the number of loads turned off at one load at a time.