Energy demand controller and method therefor

• US 4,168,491 A
• Filed: 09/29/1977
• Issued: 09/18/1979
• Est. Priority Date: 09/29/1977
• Status: Expired due to Term

• Current Assignee: Phillips Control Corp.
• Original Assignee: Phillips Control Corp.
• Inventors: Phillips, Alvin C., Cumbach, James S.
• Primary Examiner(s): Caldwell, Sr., John W.
• Assistant Examiner(s): Groody, James J.
• Application Number:
  US05/837,851
• Time in Patent Office: 719 Days
• Field of Search: 340/310 A, 340/216, 340/248 A, 340/248 C, 340/147 R, 340/661, 340/662, 340/663, 340/538, 307/35, 307/32, 307/34, 307/41, 307/38, 307/39, 307/126, 307/116, 307/140, 324/103 R, 219/485, 219/486, 219/483, 219/487, 219/492, 219/497, 219/506, 364/492, 364/493
• US Class Current: 340/501
• CPC Class Codes: H02J 2310/52 The controlling of the operation of the load not being the total disconnection of the load, i.e. entering a degraded mode or in current limitation
• CPC Class Codes: H02J 2310/54 according to a pre-established time schedule
• 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

An energy demand controller having a sensor for measuring the instantaneous power being delivered to a building, a thumb wheel switch for preselecting a power limit for use in the building, and circuitry for comparing the instantaneous power to the power limit and to switch off power to various heating zones within the building in order to maintain the instantaneous power below the preselected power limit. The control circuitry includes a cycling circuit only operative when the instantaneous power exceeds the measured power to deactivate a sufficient number of heater circuits in order to drop the instantaneous power below the preselected power limit for a predetermined time interval only. At the end of the predetermined time period, the deactivated heater circuits are turned back on. If the instantaneous power still exceeds the preselected power limit, then other zone heaters of sufficient number are likewise deactivated in a second predetermined time interval. As long as the instantaneous power exceeds the preselected power limit when the predetermined time intervals terminate, the heater circuits, in similar fashion, will be cyclically turned off and on so that heat loss in any given area is minimized. When all heater circuits within the predetermined time interval are deactivated, and the instantaneous power still exceeds the power limit, then the hot water heater is deactivated. If the instantaneous power still exceeds the preselected power limit, an alarm will then sound to inform the inhabitant of the building to either increase the preselected power limit or to deactivate other electrical circuits within the building.

Claims

1. An improved method for controlling power consumption in a building having a group of electrical users, said method having the steps of (a) preselecting a level of power consumption, and (b) determining when the actual power consumption of said building exceeds the preselected level of power consumption, said improved method further comprising the steps of:

(c) turning OFF power in cyclic order to enough users to lower the actual power consumption below the preselected level of power consumption in response to said determination and for only a predetermined time interval, the power being turned off to the aforementioned users whether or not said users are actually using power,

(d) turning ON power to all of the users in step (c) whose power was turned OFF in response to the termination of said predetermined time interval, and

(e) continually repeating steps (a) through (d) for different users next in said cyclic order so that said users are uniformly rotated in being turned OFF.

2. An improved method for controlling power consumption in a building having separate electrical heating circuits, said method having the steps of (a) preselecting a level of power consumption for said building, and (b) determining when the actual power consumption of said building exceeds the preselected level of power consumption, said improved method further comprising the steps of:

(c) turning OFF power in cyclic order to enough heating circuits to lower the actual power consumption below the preselected level of power consumption in response to said determination and only during a predetermined time interval, said predetermined time interval being less than the thermal time lag of the walls of said building,

(d) turning ON power to all of those heating circuits whose power was turned OFF in step (c) when said predetermined time interval terminates, and

(e) continually repeating steps (a) through (d) for different heating circuits next in said cyclic order so that said heating circuits are uniformly rotated in being turned OFF.

3. An improved method for controlling power consumption in a building having a first group of electrical users termed USERS 1 and a second group of electrical users termed USERS 2, said method having the steps of (a) preselecting a level of power consumption for said building, and (b) determining when the actual power consumption of the building exceeds the preselected level of power consumption, said improved method further comprising the steps of:

(c) turning OFF power in cyclic order to enough users in USERS 1 to lower the actual power consumption below the preselected level of power consumption in response to the above determination and only during a predetermined time interval,

(d) turning OFF power to at least one user in USERS 2 only when all users in USERS 1 are turned OFF in step (c) and only when the actual power consumption exceeds the preselected level of power consumption,

(e) turning ON power to all USERS 1 and 2 in steps (c) and (d) whose power was turned OFF in response to the termination of the time interval, and

(f) repeating steps (a) through (e) for different users in USERS 1 next in said cyclic order so that all users in USERS 1 are uniformly rotated in being turned OFF.

4. An improved method for maintaining power consumption in a building having separate electrical heating circuits and an electrical appliance circuit, said method having the steps of (a) preselecting a level of power consumption for said building, and (b) determining when the actual power consumption of said building exceeds the preselected level of power consumption, said improved method further comprising the steps of:

(c) turning OFF power in a predetermined order to enough heating circuits to lower the actual power consumption below the preselected level of power consumption in response to said determination and only during a predetermined time interval, said predetermined time interval being less than the thermal time lag of the walls of said building,

(d) turning OFF power to the appliance circuit only when all of the heating circuits are turned OFF in step (c) and only when the actual power consumption exceeds the preselected level of power consumption,

(e) activating an alarm when the actual power consumption exceeds the desired level of power consumption and when the power is turned OFF to the appliance circuit in step (d),

(f) turning ON power to all of those circuits in steps (c) and (d) whose power was turned OFF when said predetermined time interval terminates, and

(g) continually repeating steps (a) through (f) for different heating circuits in said predetermined order so that each heating circuit is uniformly rotated in being turned OFF.

5. An improved method for maintaining power comsumption in a building having separate electrical heating circuit, said method having the steps of (a) preselecting a level of desired power consumption, (b) generating an electrical signal proportional to said preselected level of electrical power consumption, and (c) generating an electrical signal proportional to the level of electrical power being delivered to said building, said improved method further comprising the steps of:

(d) producing a first activation pulse when the magnitude of the delivered power level signal exceeds the magnitude of the preselected power level signal,

(e) generating a time frame having a predetermined time duration in response to the production of the first activation pulse, said time duration being greater than the time for said activation pulse and less than the thermal lag time of the walls of said building,

(f) turning OFF power to a first heating circuit in response to the production of the first activation pulse,

(g) producing another activation pulse if the magnitude of the delivered power level signal still exceeds the magnitude of the preselected power level signal,

(h) turning OFF power in cyclic order to the next heating circuit in response to the activation pulse produced in the aforesaid step,

(i) repeating steps (g) and (h) throughout the duration of said time frame,

(j) turning ON power to all of the heating circuits turned OFF in steps (f) and (h) when the time frame terminates, and

(k) repeating steps (b) through (j) for different heating circuits in said cyclic order so that each heating circuit is accessed on a uniformly rotating basis.

6. An improved method for maintaining power consumption in a building having separate electrical heating circuits and an electrical appliance circuit, said method having the steps of (a) preselecting a level of power consumption, (b) generating an electrical signal proportional to said preselected level of electrical power consumption, and (c) generating an electrical signal proportional to the level of electrical power being delivered to said building, said improved method further comprising the steps of:

(d) producing a first activation pulse when the magnitude of the delivered power level signal exceeds the magnitude of the preselected power level signal,

(e) generating a time frame having a predetermined time duration in response to the production of the first activation pulse, said time duration being greater than the time for said activation pulse and less than the thermal time lag of the walls of said building,

(f) turning OFF power to a first heating circuit in response to the production of the first activation pulse and the generation of the time frame,

(g) producing another activation pulse if the magnitude of the delivered power level signal still exceeds the magnitude of the preselected power level signal,

(h) turning OFF power in a predetermined order to the next heating circuit in response to the activation pulse produced in the aforesaid step,

(i) repeating steps (g) and (h) throughout the duration of said time frame,

(j) turning OFF power to the appliance circuit only when all heating circuits are turned OFF in step (i) and only when another activation pulse is generated,

(k) turning ON power to all of the circuits in steps (f), (h) and (j) whose power was turned off when said predetermined time interval terminates, and

(l) continually repeating steps (a) through (k) for different heating circuits in said predetermined order so that said heating circuits are uniformly turned OFF.

7. An improved energy demand controller, said controller having means for delivering electrical power to said building, a plurality of users of said electrical power, means receptive of said delivered power for extending said power on a separate circuit to each of said plurality of users, means cooperative with said delivering means for generating a signal proportional to the amount of instantaneous power being delivered to said building, and means for generating a signal representative of a preselected amount of a power, said improved controller further comprising:

means receptive of said instantaneous power signal and of said preselected power signal for producing a series of activation pulses only when the magnitude of said instantaneous power signal exceeds the magnitude of said preselected power signal,

means operative upon receipt of the first activation pulse for generating a time interval of predetermined duration, said duration being less than the thermal time lag of the walls of said building,

means operative upon receipt of said pulses and the beginning of said time interval for preventing the extension of said power only during the duration of said interval in cyclic order to the number of said separate circuits in said extending means as are required to reduce the magnitude of said instantaneous power signal below the magnitude of said preselected signal, said preventing means being further responsive to the termination of said time interval for extending said power to all of the aforesaid number of circuits, said preventing means being capable in the next predetermined time interval for preventing power to the next circuits in said cyclic order.

8. An improved energy demand controller for controlling electrical power consumption by a plurality of users in a building, said controller having means for delivering electrical power to said building, means receptive of said delivered power for extending said power in a separate circuit to each user in said building, means cooperative with said delivering means for generating a signal proportional to the amount of instantaneous power being delivered to said building, and means for generating a signal representative of a preselected amount of power, said improved controller further comprising:

means receptive of said instantaneous power signal and of said preselected power signal for producing a series of activation pulses whenever the magnitude of said instantaneous power signal exceeds the magnitude of said predetermined power signal,

means operative upon receipt of said activation pulses for preventing the delivery of power to as many of said separate circuits in a predetermined first group of said users as is necessary to reduce the magnitude of said instantanteous power signal below the magnitude of said preselected signal, said preventing means being capable of preventing the delivery of power to a predetermined second group of said users only when all of said users in said first group are prevented said power and only upon receipt of said pulses, and

means operative when all of said users in said first group and at least one of said users in said second group are prevented said power for sounding an alarm and upon receipt of an activation pulse.

9. An improved energy demand controller for controlling electrical power consumption having means for delivering electrical power to said building, means receptive of said delivered power for extending said power in a separate circuit to each user in said building, means cooperative with said deliverying means for generating a signal proportional to the amount of instantaneous power being delivered to said building, and means for generating a signal representative of a preselected amount of power, said improved controller comprising:

means receptive of said instantaneous power signal and of said preselected power signal for producing a series of activation pulses only when the magnitude of said instantaneous power signal exceeds the magnitude of said predetermined power signal,

means operative upon receipt of the first activation pulse for generating a time interval of predetermined duration,

means operative upon receipt of said activation pulses and the beginning of said time interval for preventing the delivery of power in cyclic order to as many of said separate circuits in a predetermined first group of said users as is necessary to reduce said instantaneous power signal below said preselected signal, said preventing means preventing the delivery of power to a predetermined second group of said users only when all of said users in said first group are prevented said power and upon receipt of said pulses, said preventing means being operative only during said time interval, and

means operative when all of said users in said first group and said second group are prevented said power and upon receipt of an activation pulse for sounding an alarm.

10. An improved energy controller for a building, said building having electrical power lines delivering power to a plurality of electrical circuits in said building, said electrical circuits including a group of heater circuits and a circuit breaker box containing a circuit breaker for each of said electrical circuits, said controller having means cooperative with said electrical power lines for generating a signal proportional to said delivered power, and means for generating a signal proportional to a predetermined power limit, said improved controller further comprising:

means receptive of said delivered power signal and of said power limit signal for producing a series of activation pulses whenever the delivered power to said building exceeds the predetermined limit, said series of activation pulses being generated at a fixed frequency,

means operative upon receipt of the first activation pulse of said series of pulses for providing a time interval of predetermined duration, said time interval being less than the thermal time lag of the walls of said building and greater than the time period of a single activation pulse, and

means operative with the beginning of said time interval and receptive of said series of activation pulses for sequentially preventing the delivery of power to a different heater circuit according to a cyclic order for each activation pulse received in said series, said preventing means being further responsive to the termination of said time interval for becoming disabled thereby allowing delivery of power to all of the aforesaid circuits whose power was prevented during said time interval.

11. The improved energy controller of claim 10 wherein said predetermined power limit generating means is selectively capable of a plurality of different predetermined power limits.

12. The improved energy controller of claim 11 wherein said predetermined power limit generating means is a thumbwheel switch located on the inside of said building.

13. The improved energy controller of claim 10 wherein said producing means comprises:

a comparator circuit receptive of said power limit signal and of said delivered power signal for outputting a shed level indication only when said delivered power exceeds said power limit, and

a timing circuit operative upon receipt of said shed level indication for generating said activation pulses.

14. The improved energy controller of claim 10 wherein said time interval providing means comprises a timer operative upon receipt of the first activation pulse of said series of pulses for generating a square-wave pulse of said predetermined duration.

15. The improved energy controller of claim 10 wherein said preventing means comprises:

means receptive of each activation pulse in said series for outputting a control signal uniquely corresponding to a different heat circuit, said outputting means being capable of providing a control signal for each heater circuit on a uniform cyclic rotating basis, and

means in each heater circuit responsive to its control signal for switching OFF the power delivery to the aforesaid circuit.

16. The improved energy controller of claim 15 wherein said control signal outputting means comprises:

a counter receptive of each activation pulse in said series for providing a unique digital address for a heater circuit, said counter being capable of sequentially advancing from address to address with each activation pulse so that each heater circuit is addressed on a uniform rotating basis, and

a converter responsive to said addresses from said counter for extending said control signals to said switching means.

17. The improved energy controller of claim 15 wherein each of said switching means is responsive to said termination of said time interval for switching ON said power delivery.