CA1068334A - Load controlling means - Google Patents
Load controlling meansInfo
- Publication number
- CA1068334A CA1068334A CA272,343A CA272343A CA1068334A CA 1068334 A CA1068334 A CA 1068334A CA 272343 A CA272343 A CA 272343A CA 1068334 A CA1068334 A CA 1068334A
- Authority
- CA
- Canada
- Prior art keywords
- control
- loads
- signal
- group
- output
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J3/00—Circuit arrangements for ac mains or ac distribution networks
- H02J3/12—Circuit arrangements for ac mains or ac distribution networks for adjusting voltage in ac networks by changing a characteristic of the network load
- H02J3/14—Circuit arrangements for ac mains or ac distribution networks for adjusting voltage in ac networks by changing a characteristic of the network load by switching loads on to, or off from, network, e.g. progressively balanced loading
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J2310/00—The network for supplying or distributing electric power characterised by its spatial reach or by the load
- H02J2310/50—The network for supplying or distributing electric power characterised by its spatial reach or by the load for selectively controlling the operation of the loads
- H02J2310/54—The network for supplying or distributing electric power characterised by its spatial reach or by the load for selectively controlling the operation of the loads according to a pre-established time schedule
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J2310/00—The network for supplying or distributing electric power characterised by its spatial reach or by the load
- H02J2310/50—The network for supplying or distributing electric power characterised by its spatial reach or by the load for selectively controlling the operation of the loads
- H02J2310/56—The network for supplying or distributing electric power characterised by its spatial reach or by the load for selectively controlling the operation of the loads characterised by the condition upon which the selective controlling is based
- H02J2310/58—The condition being electrical
- H02J2310/60—Limiting power consumption in the network or in one section of the network, e.g. load shedding or peak shaving
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
- Y02B70/00—Technologies for an efficient end-user side electric power management and consumption
- Y02B70/30—Systems integrating technologies related to power network operation and communication or information technologies for improving the carbon footprint of the management of residential or tertiary loads, i.e. smart grids as climate change mitigation technology in the buildings sector, including also the last stages of power distribution and the control, monitoring or operating management systems at local level
- Y02B70/3225—Demand response systems, e.g. load shedding, peak shaving
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y04—INFORMATION OR COMMUNICATION TECHNOLOGIES HAVING AN IMPACT ON OTHER TECHNOLOGY AREAS
- Y04S—SYSTEMS INTEGRATING TECHNOLOGIES RELATED TO POWER NETWORK OPERATION, COMMUNICATION OR INFORMATION TECHNOLOGIES FOR IMPROVING THE ELECTRICAL POWER GENERATION, TRANSMISSION, DISTRIBUTION, MANAGEMENT OR USAGE, i.e. SMART GRIDS
- Y04S20/00—Management or operation of end-user stationary applications or the last stages of power distribution; Controlling, monitoring or operating thereof
- Y04S20/20—End-user application control systems
- Y04S20/222—Demand response systems, e.g. load shedding, peak shaving
Abstract
Abstract of the Disclosure A demand controller for connecting and disconnecting loads from a power source has a plurality of control elements in two priority groups, an equal priority group and a set priority group..
Loads are controlled by the control elements to be connected and disconnected. A control means directs signals for restoring and shedding the loads and for the priority between the two groups of control elements.
Loads are controlled by the control elements to be connected and disconnected. A control means directs signals for restoring and shedding the loads and for the priority between the two groups of control elements.
Description
3`
~L06i8334 This application relates to load control systems, particularly 10 ¦to demand control systems that connect and disconnect loads from 11 ~an electrical source in response to a measure of the total current 12 !consumed by the loads.
13 '~ In many industrial and commercial installations electrical 14 11 loads powered by the incoming electrical utility power source can 15 ll be used under various conditions for different intervals and 16 1 therefore savings in power use can be achieved by controlling the 17 ! period of operation. Also, utility charges are often set so that 18 ,¦excessive peak power consumption results in increased rates.
l9l¦Accordingly, in many installations it is desirable to limit peak 20 ¦! load conditions by providing a device that connects and disconnect 21 1l loads as the total power consumption varies.
22 1 Devices used to accomplish this function are often called 23 l demand controllers and generally are of the type that senses the 24 level of current being used and connects loads when the current 25 l drops below a preselected level and disconnects loads when the 26 ¦ current rises above another preselected level. In this manner 27 ¦¦the maximum desirable number of loads are connected at all times 28 ¦¦and the load demand is kept below excessive levels either to limit 29 I peak load rate assessment or to even out load peaks and thereby 3 l¦reduce total consumption.
31i Demand controllers generally connect and disconnect loads 32 ! under some priority system in a permanently wired installation.
Il .. . . " i . .
, . : , ....
,1 10~3334 ;
1 Relays con-trol respective loads and a control system activates and
~L06i8334 This application relates to load control systems, particularly 10 ¦to demand control systems that connect and disconnect loads from 11 ~an electrical source in response to a measure of the total current 12 !consumed by the loads.
13 '~ In many industrial and commercial installations electrical 14 11 loads powered by the incoming electrical utility power source can 15 ll be used under various conditions for different intervals and 16 1 therefore savings in power use can be achieved by controlling the 17 ! period of operation. Also, utility charges are often set so that 18 ,¦excessive peak power consumption results in increased rates.
l9l¦Accordingly, in many installations it is desirable to limit peak 20 ¦! load conditions by providing a device that connects and disconnect 21 1l loads as the total power consumption varies.
22 1 Devices used to accomplish this function are often called 23 l demand controllers and generally are of the type that senses the 24 level of current being used and connects loads when the current 25 l drops below a preselected level and disconnects loads when the 26 ¦ current rises above another preselected level. In this manner 27 ¦¦the maximum desirable number of loads are connected at all times 28 ¦¦and the load demand is kept below excessive levels either to limit 29 I peak load rate assessment or to even out load peaks and thereby 3 l¦reduce total consumption.
31i Demand controllers generally connect and disconnect loads 32 ! under some priority system in a permanently wired installation.
Il .. . . " i . .
, . : , ....
,1 10~3334 ;
1 Relays con-trol respective loads and a control system activates and
2 ~ deactivates the relays in response to a restore load condition or
3 ,la shed load condition as they occur. Prior art demand controllers -
4 ,'however, are not particularly flexible and do not provide for more
5 Ithan one type of priority switching sequence.
6 ll With this invention a new and improved demand controlling
7 ~jmeans uses modular construction that enables plug-in units to be
8 l¦used to control any number of loads and provides for a selection
9 j of priority systems for groups of loads. A demand controller
10 ¦ according to this invention can be manufactured as a standard
11 ¦ package and any selected number of plug-in modules, one for each
12 l¦ load, can be used to control the loads present in any particular
13 ll installation. The controller also can establish two priority
14 ¦ systems so that two groups of loads may be connected and dis-
15 l connected in different sequences depending on the needs of the
16 ¦particular installation. A selective priority system for con-
17 '¦necting and disconnecting loads is desirable since some loads are
18 iconsidered o~ equal importance and can be turned on and off in
19 Ithe same sequence while others may have comparatively different
20 !importance and are preferably turned on and off in a different
21 l¦sequence. '
22 1¦ Other advantages and objects of this invention will be apparent
23 llfrom the following description.
24 ~ FIG. 1 is a general block diagram and simplified mechanical
25 ~ representation of a demand controller system according to this
26 1 invention; and
27 l FIG. 2, 3 and 4 are each a part of the demand controller shown
28 ¦in FIG. 1 in more detail.
29 ¦ Referring to FIG. 1, a demand controller that can be used in 3 lany general, industrial or commercial installatlon is connected 31l¦to a power source, such as an al-ternating current three phase 32l~power source 10, which is connected in any known manner (not shown) ~ i ~
106833~
., .
1 'Ito power loads 151, 161, 171, 211, 221 and 231 through a service 2 !lentrance breaker 11 and through current transformers 14 that are 3 ,Iconnected to measure the current in each of the three phases in .
4 ''lany known manner. A sensing means 12 for producing after a 5 ,Ipreselected time delay a first output signal when the current is 6 Ijabove a first preselected level and a second output signal when 7 1 the current is below a second preselected level comprises measur- .
8 1 ing means 13 for producing an output varying as a function of the g I total current in the power system, a comparing means 19 for 10 ¦ producing the first and second output signal, and a time delay 11 means for delaying the output signalsO The measuring means con-12 verts the output of the current transformers received along 13 l lines lS to a direct current that varies as a function of the 14 ¦ total current through the current transformers and applies its 5 l output along line 18M to comparing means 19.
16 ¦¦ The comparing means produces a first output signal, or shed .
17 ¦I signal, along line S when the measuring means output is akove the 18 l¦ first preselected level, and a second output signal, or restore 19l signal, along line R when the measuring means output is below the 20¦ second preselected level. Comparing means 19 may be of any type 21 ¦known in the art that compares an input to a preselected reference 22 ¦¦ to produce two respective outputs, one when the input is above the .
23¦¦reference by a selected amount and the other when the signal is 24~lbelow the reference by a selected amount.
25~ The signals from the comparing means are received by time 26¦ delay means 22 which produces the corresponding shed output 27 ll signals and restore output signals along lines S and R, respec- .
28¦ tively after preselected time delays in any manner known in the 29¦ ar.t. Two time delay functions are used as known in the art. A
3ol first t.i.me delay of short.duration functions to prevent pro-31¦~duction of a shed or restore signal in response to a momentary or 32¦transient condition on the power system. A second time delay ll . -3-~ ,, ,, ,,__;__ .. ___ . - ........................... .. ~.. v ~ ~A , ~1 ~IL068334 1 Ibetween consecutive shed or restore signals delays the output for 2 il a selected time interval to permit the current conditions to 3 1¦ stabilize after switching has occurred. These t1me intervals are 4 ll selected for particular characteristics and types of loads en-5 llcountered in any particular installation.
, The output of the sensing means, either a shed or restore 7 ~ output signal, is applied to a control means 20 for producing 8 1 control signals for the priority groups.
9 ¦ The control means output is connected by a multiple conductor 10 Il¦loO to a first priority group having a plurality of equal priority 11 ¦ control elements 50, 60 and 70 and to a second priority group 12 1 having a plurality of set priority control elements 110, 120 and 13 130. The two priority groups control the corresponding loads 14 1 through each of the control elements along respective control 15 ~ lines 50C, 60C, 70C, llOC, 120C and 130C to control relays 150, 16 1160, 170, 210, 220 and 230. The control relays respectively 17 l¦ control loads 151, 161, 171, 211, 221 and 231 in any manner known 18 ll in the art.
19 l~ The system is shown schematically and with a physical or 20 !mechanical relationship. The control elements are plug-in modules 21 ,l f any type known in the art that plug into receptacles. A
22 Iplurality of adjacent receptacles corresponding to the control 23 l element positions as shown receive the modules. The plugging in 24 1 of a control element module connects each module to a backboard 25 l f conductors including multiple conductor groups 101 and 103 26 ¦ connected to all receptacles and multiple conductor groups 50', 27 ~ 60', 70', 80', 110' and 120' connected between juxtaposed 28 ¦ receptacles.
29 ¦ The equal priority control elements operate to turn the loads 3o lon and off in sequence with the first load turned on being the 31 ll¦ first one turned off and the first turned off being the first 32 l~ turned on. For example, if all the loads are connected to the '11 Il -4_ ~ . ~ . -- ..... . ...
1 jlsource by control elements 50, 60 and 70, upon the receipt of a 2 ¦~shed signal by the euqal priority group, one of the loads, for 3 1¦ example load 151, would be disconnected. Upon the next shed 4 ''Isignal load 161 would be disconnected. At this point, upon the 5 'loccurrence of a restore signal, control element 50 would operate 6 to connect load 151. Upon the occurrence of a further shed signal 7 ; control element 70 would operate to disconnect load 171 and so on.
8 With respect to the set priority group, upon the input of a 9 ¦ shed signal with all the loads connected, control element 110 10 ¦ would disconnect load 211 which would be followed by load 221. r 11 ¦ Occurrence of a restore signal at this point would operate control 12 1 element 120 to reconnect load 221 and so on.
13 ! Control means 20 comprises a means for selecting delivery of 14 ¦ its output to select the priority between the two systems and 15 1would typically be operated so that all the loads of the equal 16 jlpriority group would be disconnected before any loads of the set 17 ¦priority group would be disconnected and all the set priority load 18 l~would be connected before any equal priority loads would be con-19 1 nected.
20~ Referring to FIGS. 2, 3 and 4 showing the details of the 21 11 system in FIG. 1, control elements 50, 60, 70, 110, 120 and 130 22l are shown schematically and physically in a generalized manner ~to 23¦lillustrate the wiring. The control elements are a group of plug-ir 24'1modules or boards, an equal priority board and a set priority 251~board, respectively, having mechanical connections of any known 26l~type that upon insertion of the board make the connections shown 27 1to interconnecting multiple conductor 100, interconnecting 28!multiple conductor 103, and interconnecting conductors 40', 50', 29l60', 70', 80', 110', 120' and 130' connected between each of the 3l réspective boards. The backboard of any suitable panel is designec 31l in any known manner to receive any selected number of modules with 32 each module pluggable into the groups of conductors to make the Il Il ~ ~1 ~' ,.............. .
. _ .... ~ .. . . . . .. .
~06~3334 .
l 1Iconnections schematically. To separate the two priority groups a 2 l~blank space ~0 is left between the two priority groups to break 3 l1the interconnecting conductors between juxtaposed receptacles.
4 'I The control means is connected to the priority boards through 5 I~multiple conductor l0l which has eight conductors, A through H.
6 ~!The priority boards are interconnected through multiple conductor 7 lll00 which has nine conductors, A through H plus X, and through 8 ~¦multiple conductor 103 which has four conductors, J, K, L and M.
~ ~ Referring particularly to FIG. l, control means 20 comprises l0 ¦ a means 40 for connecting or restoring loads and a means 30 for ll l!disconnecting or shedding loads. The means for disconnecting 12 Iloads produces an output at line A to the set priority group for 3 ll shedding loads in the set priority group and an output at line B
14 ! to the equal priority group for shedding loads in the equal 15 ll priority group with line C receiv:ing an input indicating the l~ ¦ condition of the loads controlled by the set priority group and 17 l line D receiving an input indicat:ing the condition of the loads 18 'i1 controlled by the equal priority group.
l9 ¦ Means for shedding loads 30 comprises a NOR circuit, or in-20 llverter, 31, a NOR circuit, or inverter, 32, control NOR gates 2ll~33 and 34, and a means for selecting shed priority between the 22 ¦Itwo priority groups that comprises a switch 35 and a switch 36.
23 11 Similarly means for restoring loads 40 comprises a NOR circuit 24 lor inverter, 41, a NOR circuit, or inverter, 42, control NOR gates 25 143 and 44, and a means for selecting restore priority between the 26 1 two priority groups that comprises a switch 45 and a switch 46.
27 l The control means functions in response to the receipt of 28¦ shed and restore signals and to inputs from the priority groups.
291 The various conditions for the logic of the system are as follows.
106833~
., .
1 'Ito power loads 151, 161, 171, 211, 221 and 231 through a service 2 !lentrance breaker 11 and through current transformers 14 that are 3 ,Iconnected to measure the current in each of the three phases in .
4 ''lany known manner. A sensing means 12 for producing after a 5 ,Ipreselected time delay a first output signal when the current is 6 Ijabove a first preselected level and a second output signal when 7 1 the current is below a second preselected level comprises measur- .
8 1 ing means 13 for producing an output varying as a function of the g I total current in the power system, a comparing means 19 for 10 ¦ producing the first and second output signal, and a time delay 11 means for delaying the output signalsO The measuring means con-12 verts the output of the current transformers received along 13 l lines lS to a direct current that varies as a function of the 14 ¦ total current through the current transformers and applies its 5 l output along line 18M to comparing means 19.
16 ¦¦ The comparing means produces a first output signal, or shed .
17 ¦I signal, along line S when the measuring means output is akove the 18 l¦ first preselected level, and a second output signal, or restore 19l signal, along line R when the measuring means output is below the 20¦ second preselected level. Comparing means 19 may be of any type 21 ¦known in the art that compares an input to a preselected reference 22 ¦¦ to produce two respective outputs, one when the input is above the .
23¦¦reference by a selected amount and the other when the signal is 24~lbelow the reference by a selected amount.
25~ The signals from the comparing means are received by time 26¦ delay means 22 which produces the corresponding shed output 27 ll signals and restore output signals along lines S and R, respec- .
28¦ tively after preselected time delays in any manner known in the 29¦ ar.t. Two time delay functions are used as known in the art. A
3ol first t.i.me delay of short.duration functions to prevent pro-31¦~duction of a shed or restore signal in response to a momentary or 32¦transient condition on the power system. A second time delay ll . -3-~ ,, ,, ,,__;__ .. ___ . - ........................... .. ~.. v ~ ~A , ~1 ~IL068334 1 Ibetween consecutive shed or restore signals delays the output for 2 il a selected time interval to permit the current conditions to 3 1¦ stabilize after switching has occurred. These t1me intervals are 4 ll selected for particular characteristics and types of loads en-5 llcountered in any particular installation.
, The output of the sensing means, either a shed or restore 7 ~ output signal, is applied to a control means 20 for producing 8 1 control signals for the priority groups.
9 ¦ The control means output is connected by a multiple conductor 10 Il¦loO to a first priority group having a plurality of equal priority 11 ¦ control elements 50, 60 and 70 and to a second priority group 12 1 having a plurality of set priority control elements 110, 120 and 13 130. The two priority groups control the corresponding loads 14 1 through each of the control elements along respective control 15 ~ lines 50C, 60C, 70C, llOC, 120C and 130C to control relays 150, 16 1160, 170, 210, 220 and 230. The control relays respectively 17 l¦ control loads 151, 161, 171, 211, 221 and 231 in any manner known 18 ll in the art.
19 l~ The system is shown schematically and with a physical or 20 !mechanical relationship. The control elements are plug-in modules 21 ,l f any type known in the art that plug into receptacles. A
22 Iplurality of adjacent receptacles corresponding to the control 23 l element positions as shown receive the modules. The plugging in 24 1 of a control element module connects each module to a backboard 25 l f conductors including multiple conductor groups 101 and 103 26 ¦ connected to all receptacles and multiple conductor groups 50', 27 ~ 60', 70', 80', 110' and 120' connected between juxtaposed 28 ¦ receptacles.
29 ¦ The equal priority control elements operate to turn the loads 3o lon and off in sequence with the first load turned on being the 31 ll¦ first one turned off and the first turned off being the first 32 l~ turned on. For example, if all the loads are connected to the '11 Il -4_ ~ . ~ . -- ..... . ...
1 jlsource by control elements 50, 60 and 70, upon the receipt of a 2 ¦~shed signal by the euqal priority group, one of the loads, for 3 1¦ example load 151, would be disconnected. Upon the next shed 4 ''Isignal load 161 would be disconnected. At this point, upon the 5 'loccurrence of a restore signal, control element 50 would operate 6 to connect load 151. Upon the occurrence of a further shed signal 7 ; control element 70 would operate to disconnect load 171 and so on.
8 With respect to the set priority group, upon the input of a 9 ¦ shed signal with all the loads connected, control element 110 10 ¦ would disconnect load 211 which would be followed by load 221. r 11 ¦ Occurrence of a restore signal at this point would operate control 12 1 element 120 to reconnect load 221 and so on.
13 ! Control means 20 comprises a means for selecting delivery of 14 ¦ its output to select the priority between the two systems and 15 1would typically be operated so that all the loads of the equal 16 jlpriority group would be disconnected before any loads of the set 17 ¦priority group would be disconnected and all the set priority load 18 l~would be connected before any equal priority loads would be con-19 1 nected.
20~ Referring to FIGS. 2, 3 and 4 showing the details of the 21 11 system in FIG. 1, control elements 50, 60, 70, 110, 120 and 130 22l are shown schematically and physically in a generalized manner ~to 23¦lillustrate the wiring. The control elements are a group of plug-ir 24'1modules or boards, an equal priority board and a set priority 251~board, respectively, having mechanical connections of any known 26l~type that upon insertion of the board make the connections shown 27 1to interconnecting multiple conductor 100, interconnecting 28!multiple conductor 103, and interconnecting conductors 40', 50', 29l60', 70', 80', 110', 120' and 130' connected between each of the 3l réspective boards. The backboard of any suitable panel is designec 31l in any known manner to receive any selected number of modules with 32 each module pluggable into the groups of conductors to make the Il Il ~ ~1 ~' ,.............. .
. _ .... ~ .. . . . . .. .
~06~3334 .
l 1Iconnections schematically. To separate the two priority groups a 2 l~blank space ~0 is left between the two priority groups to break 3 l1the interconnecting conductors between juxtaposed receptacles.
4 'I The control means is connected to the priority boards through 5 I~multiple conductor l0l which has eight conductors, A through H.
6 ~!The priority boards are interconnected through multiple conductor 7 lll00 which has nine conductors, A through H plus X, and through 8 ~¦multiple conductor 103 which has four conductors, J, K, L and M.
~ ~ Referring particularly to FIG. l, control means 20 comprises l0 ¦ a means 40 for connecting or restoring loads and a means 30 for ll l!disconnecting or shedding loads. The means for disconnecting 12 Iloads produces an output at line A to the set priority group for 3 ll shedding loads in the set priority group and an output at line B
14 ! to the equal priority group for shedding loads in the equal 15 ll priority group with line C receiv:ing an input indicating the l~ ¦ condition of the loads controlled by the set priority group and 17 l line D receiving an input indicat:ing the condition of the loads 18 'i1 controlled by the equal priority group.
l9 ¦ Means for shedding loads 30 comprises a NOR circuit, or in-20 llverter, 31, a NOR circuit, or inverter, 32, control NOR gates 2ll~33 and 34, and a means for selecting shed priority between the 22 ¦Itwo priority groups that comprises a switch 35 and a switch 36.
23 11 Similarly means for restoring loads 40 comprises a NOR circuit 24 lor inverter, 41, a NOR circuit, or inverter, 42, control NOR gates 25 143 and 44, and a means for selecting restore priority between the 26 1 two priority groups that comprises a switch 45 and a switch 46.
27 l The control means functions in response to the receipt of 28¦ shed and restore signals and to inputs from the priority groups.
291 The various conditions for the logic of the system are as follows.
30 IConsidering the shedding procedure, the shed output along line S
31¦~from the time delay means is normally at a high level, referred 32l~to hereinafter as one, and upon production of a shed signal, a Il .
ll -6-,~ , v' , . ..
1 'pulse, momentarily changes from a one to a zero condition to 2 l¦produce a zero pulse as an input along line S to NOR gates 33 and 3 ,34. The inputs from the priority groups are such that line C is 4 'lat one whenever any set priority load is connected and line D
5 ,~is at one whenever any equal priority load is connected. Switch 6 ~136 is closed so that the input along line D is directly applied 7 !jas an input to NOR gate 33 and swi-tch 35 is open so that line C
8 lis not connected as an input to NOR gate 34, thus maintaining that ~ llinput at zero. Thus, when both line C and line D are at one a 10 Iblocking signal is applied to the one of the NOR inputs of the 11 ¦ NOR gates 33 and 34 selected by the positioning of switches 35 12 ¦and 36. ~t the sa~,e time the inputs along lines C and D are 13 ¦inverted to enable the corresponding NOR gates when at one and 14 ¦disable them when at zero.
15 ¦ Thus with lines C and D at one a shed signal switches only 16 INOR gate 34 to produce an output pulse, zero to one to zero, along 17 Illine B to the equal priority group. When all the equal priority 18 ¦loads are disconnected, line D is at zero which enables NOR
19 llgate 33 and disables NOR gate 34. The next shed pulses will then 20 llbe applied through NOR gate 33 along line A to the set priority 21 `~igroup until all the set priority loads are disconnected.
22 ,j The control means operates in the same manner for restoring 23 l loads. The inputs along lines E and F from the two priority group 24 'I are at one whenever any load of its respective priority group is 25 l disconnected. Switches 45 and 46 are positioned so that as long 26 1 as a load is disconnected in the set priority group the input 27 l along line E will be at one and will block or disable NOR gate 44, 28 ¦ which controls the equal priority group along line H, and enable 29,lNOR gate 43 through inverter 41. Upon the occurrence of a restore 30llpulse, which operates in the same manner as the shed pulse, that 31¦~is, it goes from a one to a zero and returns -to one, a pulse will 32llbe sent by NOR gate 43 along line G to connect the next load in ll Il -7-J~
106833~
1 l~the set priority group.
2 1, When all the loads of the set priority group are connected, 3 lline E changes to zero and this through inverter 41 blocks NOR
4 igate 43 and enables WOR gate 44 through switch 45. As long as the 5 ,! equal priority group input along line F is at a one, indicating 6 ¦that at least one load is not connected, the input to NOR gate 44 7 ¦will be at zero and NOR gate 44 will produce a puIse upon the 8 loccurrence of a restore signal until all the loads in the equal ! priority group are connected.
lO , Thus the control operates by shedding all the loads in the 11 1 equal priority group first and by restoring all the loads in the 12 1 set priority group first. The control elements receive the inputs 13 from the control means along the back wiring group or intercon-14 1 necting conductors. Interconnections are also made between the 15 l priority boards along a second back wiring group, or intercon-16 ¦necting conductors, 103 and connections are made between juxtaposec 17 Iboards of the same priority group by back wiring groups, or inter-18 ¦connecting conductors, 50, 60, 110 and 120. Blank space 80 breaks 19 l¦the connections between the receptacles for control elements 70 20 ¦and 110 so that back wiring groups 70' and ~0' are terminating 21'1points If no additional control elements are used, back wiring 22 '¦groups 40' and 130' are also terminating points.
23 il Each control element produces an output that controls a 241lrespective control relay with control elements 50, 60, 70, 110, 251¦120 and 130 each controlling control relays 150, 160, 170, 210, 26 ¦¦ 220 and 230, respectively. Each of the control relays controls 27 l its corresponding loads 151, 161, 1~71, 211, 221 and 231, respec-28j tively, in any manner known in the art. The logic of the system 29 ! as shown is that ene~gization of a control relay occurs when the 3oll corresponding control line, lines 50C, 60C, 70C, 110C, 120C and 31¦¦130C, is in a one condition. The load control contact is a
ll -6-,~ , v' , . ..
1 'pulse, momentarily changes from a one to a zero condition to 2 l¦produce a zero pulse as an input along line S to NOR gates 33 and 3 ,34. The inputs from the priority groups are such that line C is 4 'lat one whenever any set priority load is connected and line D
5 ,~is at one whenever any equal priority load is connected. Switch 6 ~136 is closed so that the input along line D is directly applied 7 !jas an input to NOR gate 33 and swi-tch 35 is open so that line C
8 lis not connected as an input to NOR gate 34, thus maintaining that ~ llinput at zero. Thus, when both line C and line D are at one a 10 Iblocking signal is applied to the one of the NOR inputs of the 11 ¦ NOR gates 33 and 34 selected by the positioning of switches 35 12 ¦and 36. ~t the sa~,e time the inputs along lines C and D are 13 ¦inverted to enable the corresponding NOR gates when at one and 14 ¦disable them when at zero.
15 ¦ Thus with lines C and D at one a shed signal switches only 16 INOR gate 34 to produce an output pulse, zero to one to zero, along 17 Illine B to the equal priority group. When all the equal priority 18 ¦loads are disconnected, line D is at zero which enables NOR
19 llgate 33 and disables NOR gate 34. The next shed pulses will then 20 llbe applied through NOR gate 33 along line A to the set priority 21 `~igroup until all the set priority loads are disconnected.
22 ,j The control means operates in the same manner for restoring 23 l loads. The inputs along lines E and F from the two priority group 24 'I are at one whenever any load of its respective priority group is 25 l disconnected. Switches 45 and 46 are positioned so that as long 26 1 as a load is disconnected in the set priority group the input 27 l along line E will be at one and will block or disable NOR gate 44, 28 ¦ which controls the equal priority group along line H, and enable 29,lNOR gate 43 through inverter 41. Upon the occurrence of a restore 30llpulse, which operates in the same manner as the shed pulse, that 31¦~is, it goes from a one to a zero and returns -to one, a pulse will 32llbe sent by NOR gate 43 along line G to connect the next load in ll Il -7-J~
106833~
1 l~the set priority group.
2 1, When all the loads of the set priority group are connected, 3 lline E changes to zero and this through inverter 41 blocks NOR
4 igate 43 and enables WOR gate 44 through switch 45. As long as the 5 ,! equal priority group input along line F is at a one, indicating 6 ¦that at least one load is not connected, the input to NOR gate 44 7 ¦will be at zero and NOR gate 44 will produce a puIse upon the 8 loccurrence of a restore signal until all the loads in the equal ! priority group are connected.
lO , Thus the control operates by shedding all the loads in the 11 1 equal priority group first and by restoring all the loads in the 12 1 set priority group first. The control elements receive the inputs 13 from the control means along the back wiring group or intercon-14 1 necting conductors. Interconnections are also made between the 15 l priority boards along a second back wiring group, or intercon-16 ¦necting conductors, 103 and connections are made between juxtaposec 17 Iboards of the same priority group by back wiring groups, or inter-18 ¦connecting conductors, 50, 60, 110 and 120. Blank space 80 breaks 19 l¦the connections between the receptacles for control elements 70 20 ¦and 110 so that back wiring groups 70' and ~0' are terminating 21'1points If no additional control elements are used, back wiring 22 '¦groups 40' and 130' are also terminating points.
23 il Each control element produces an output that controls a 241lrespective control relay with control elements 50, 60, 70, 110, 251¦120 and 130 each controlling control relays 150, 160, 170, 210, 26 ¦¦ 220 and 230, respectively. Each of the control relays controls 27 l its corresponding loads 151, 161, 1~71, 211, 221 and 231, respec-28j tively, in any manner known in the art. The logic of the system 29 ! as shown is that ene~gization of a control relay occurs when the 3oll corresponding control line, lines 50C, 60C, 70C, 110C, 120C and 31¦¦130C, is in a one condition. The load control contact is a
32¦normally open function so that when the relay is energized the ~'' , ;
106~334 'I , 1 Ijrespective load is disconnected from the source. In this manner 2 ja failure of the demand controller system automatically connects 3 ,lall the loads to the source.
4 1 Referring to FIG. 4, equal priority control element 50 comprls~ !S
5 lltransfer memories 51 and 52, a flip-flop circuit 53, or gates 54 6 lland 55, reset switches 56 and 57, a multiple control switch 58, 7 1l and an inverting amplifier 59.
8 1l¦ Transfer memory 51, and the other similar transfer memories 9 I 52, 61, 62, 71 and 73, is a known device that produces a set of 10 ¦ complementary outputs and has a set input a, a reset input c, a 11 j control input b, a first output f and a first enabling input g 12 for the first output, and a second output e, which is the com-13 1 plement of the first output, and a second enabling input d for 14 ~ the second output. The set and reset inputs are controlling so 15 l that upon a set input, i.e., a one pulse, the first output will 16 Ibe changed to a one, thus switching the second output to a zero, 17 ~¦regardless of any of the conditions of the other inputs. Similarl~
18 1l upon a reset input of a one pulse the second output will be changet 19 Ito a one, and the first output to zero, regardless of any of the 20 ¦¦conditions of the other inputs. The enabling inputs control the 21 ~llmemory so that a change in the condition of the transfer memory 22 ¦will occur only if an enabling input and its corresponding output 23 l are at zero.
24 1 Flip-flop circuit 53, and the other similar flip-flop circuits 25 163 and 73, is a standard device known in the art that produces a 26 ¦set of complementary outputs and a first input a, a second input 27 I!b, a reset lnput c, a first output f, a first enabling input g, 28l a second output e, the complement of the first output, and a 29l second enabling input d. The circuit is of any -type known in the 30¦1art that changes the outputs only when a zero going pulse is 31¦~received at an input and the corresponding enabling input is at 32¦¦a zero. The output of flip-flop circuit 53 are applied to the Il Il _g _ ., , ~ , .. . . . . .: ..
~8 1 ,¦control means through OR gates 54 and 55, respectively, and to 2 llcontrol relay 150 through inverting amplifiex 59 along line 50C.
3 Reset switches 56 and 57 are positioned in the reset line and .
4 ¦idetermine the sequence for starting of the system. Switch 58 5 llmakes the appropriate return connections from the last to the 6 first control element through interconnecting conductors 103.
7 1 Equal priority control elements are interconnected through .
8 I'back connections 50' and 60'. Elements 60 and 70 are the same as 9 l¦control element 50 and corresponding last digits of identifying 10 Inumbers are used to indicate corresponding components.
Referring to FIG. 3, set priority control element, or board 12 ¦ 110, comprises a flip-flop circuit 116, OR gates 111 and 112, 13 connecting switches 113 and 114, and an inverting amplifier 115.
14 ¦Flip-flop circuit 116, and the corresponding flip-flop circuits .
15 1126 and 136 in the other control elements, is of the same type 16 ¦as flip-flop circuits 53, 63 and 73 in the equal priority control .
17 ¦elements and has a first input a, a second input b, a reset input 18 ¦Ic, a first output f, a first enabling input g, a second output e, 19 l¦the complement of the first output, and a second enabling input d.
20 ¦The outputs of flip-flop circuit 116 are applied to the control 21¦1means through OR gates 111 and 112, respectively, and to control 22 llrelay 210 through power inverter 115 along line 110C.
23 jl Set priority control elements 120 and 130 are the same as 24l control element 110 and corresponding last digits of identifying 25 numbers are used to indicate corresponding components. The set 26 priority control elements are interconnected through back con-27 l nections 110' and 120'. Switches 113 and 114, and corresponding .
28 1 switches in control elements 120 and 130, select the set priority 29 ¦ sequence.
3o I In the operation of the circuitry shown, upon initial energi-31 ¦zation of the demand controller and associated power system a .
32 ¦reset control 49 of any known type produces an initial pulse, I
~ .. ... ~
'- 106833~ , 1 I;going to one, along line X to each of the control elements. This 2 ! operates to disconnect all the loads so that the demand controller system can ~egin operating to restore the loads one by one until 4 ,~the selected restore signal level, or current, is exceeded. The 5 ll off or reset pulse is applied along line X to the transfer 6 l¦ memories in the equal priority control elements and to the flip-7 ¦flop circuits in all the control elements. For purposes of 8 Isimplifying the description the first output of any of the trans-~ Ifer memories or flip-flop circuits will be referred to in dis-10 l~cussing the state of the flip-flop circuits with an "on" condition 11 Ijmeaning that the first output is on, or in a one condition, and 12 l¦ the second output is off, or in a zero condition.
13 l The reset pulse along line X is applied through the reset 14 ¦ switches of each control element. In control element 50, switch 15 i 56 is open and switch 57 is closed to apply the pulse to set 16 1 input a of transfer memories 51 and 52 to turn them on. Control 17 il elements 60 and 70 have switches 66 and 67 and 76 and 77 positione( I
18 li oppositely to switches 56 and 57 and this applies the reset pulse l9ijto reset input c of transfer memories 61, 62, 71 and 72 to turn 20lithem off. The reset pulse is also applied to the reset inputs c 21 ¦ of flip-flop circuits 53, 63, 73, 116, 126 and 136 to turn them 22 1 off. This applies a zero input to the respective inverting 23 l amplifiers and a one input to the respective control relays. This 24 energizes the control relays to break the normally closed contacts 25 ~ and disconnect all the loads.
26 , Under the conditions occurring immediately after the reset 27 ! pulse with all the loads disconnected, the demand controller 28 system, after the selected time delay in the time delay means and 29 ¦if the current level of the loads is low enough, will produce a 3 restore pulse to control means 20 which will produce a one pulse 311 along line G. This occurs because lines E and F are at one (the 32j ff condition of the flip-flop circuits) and this blocks NOR gate ll ~, ,i _,____~ _ r . . .. .. . . . . ... .
l06a334 1 1144 and enables NOR gate 43 to respond to the restore pulse.
2 1¦ The pulse along line G is received by the set priority group, 3 l¦and received at the second input c of the flip-flop circuit.
4 ISwitches 113, 114, 123, 124, 133 and 134 in control elements 5 1 110, 120 and 130 are positioned so that the enabling input d of 6 only flip-flop circuit 136 is connected to a zero, or enabling, 7 ! point Y so that only flip-flop circuit 136 will respond to the 8 llpulse. The enabling inputs d of flip-flop circuits 116 and 126 9 l¦are connected to the second outputs e of flip-flop circuits 126 lO I and 136, respectively, which are at a one condition, through 11 ¦lines 110V and 120V, respectively and therefore are not enabled.
12 j The restore pulse therefore turns on flip-flop circuit 136 which 13 ~ de-energizes control relay 230 and connects load 231 to the load.
14 ~ The change in flip-flop circuit 136 changes input c of flip-flop 15 1 circuit 126 along line 120V from second output e of flip-flop 16 ! circuit 136.
17 ~ Upon occurrence of the next restore pulse after the selected 18 !linterval provided by the time delay means, if the current being 19~ drawn by the entire load system has not reached the selected 20 level, flip-flop circuit 126 will be turned on, load 221 will be 21 ,connected to the load, and the second enabling input d of flip-22 ¦flop circuit 116 will go to zero and be enabled. The next restore 23¦!pUlse similarly will turn on flip-flop circuit 116 and connect 241 load 211 to the source. This places all the set priority flip-25l flop circuits in an off condition which changes the condition of 26¦ line E to a zero thereby disabling NOR gate 43 and enabling NOR
27 ¦gate ~4 in the control means. Subsequent restore pulses will 28llSub5equently be applied to the equal priority group.
29l¦ The next restore pulse is applied along line H to the equal 3'priority group. The restore pulse is received by all three 311 flip-flop circuits 53, 63 and 73 in control elements 40, 60 and 32l 70' respectively as an input to their second inputs b. Flip-flop Il ~.
r-- ,-.
_, . . . . .
~833~
1 circuits 63 and 73 do not change because their second enabling 2 ¦inputs d are at a one condition since they are respectively con-3 1¦ nected to the second outputs e of transfer memories 62 and 72 4 l~which are in an off condition. Transfer memory 52, however, was 5 Iplaced in an on condition by the reset pulse which applies a zero 6 ¦!to enabling input d and enables the second output of flip-flop 7 1l circuit 53 which is accordingly turned on. First output f goes 8 I!to one and line 50C goes to zero to de-energize control relay 150 Y ~land connect load 151 to source 10.
lO I The restore pulses are also applied to input b of the restore transfer memories. Since transfer memory 52 has its second 12 ! enabling input at zero, from first output f of transfer memory 72 13 ll which is off, and its second output at zero, since it is turned 14 on, the restore pulse will turn off transfer memory 52. Similarly 15 lltransfer memory 62 has its first enabling input g and its first 16 '¦outPut f at zero and is turned on by the restore pulse. Transfer 17 ''~emory 72 remains in an off condition since its first enabling, 18 Ilinput g is one and its second output f is at one.
19 Upon the receipt of a second restore pulse, flip-flop circuit 20l 63 will be turned on to connect load 161 to the source. Transfer 211 memory 62 will change condition to change first enabling input d 22 'of flip-flop circuit 73 and thereby place flip-flop circuit 73 23 1l in an enabled condition for the receipt of the next restore pulse.
24,¦ Upon receipt of the next restore pulse flip-flop circuit 73 ' 25¦1is turned on to de-energize control relay 170 and connect load 171 26¦¦to the source.
27 llj Upon the change in output condition of flip-flop circuit 73 28llall the flip-flop circuits are turned on and the input along line 2gllto the control means is changed so that both NOR gates 43 and 44 3ol are in a blocked condition.
311 With the reverse operation of shedding loads, upon production 32 if a shed pulse, the control means and control elements operate !¦ -13-L ;
.... .
106833~ ~
l ¦¦in the same general manner in the reverse direction to disconnect 2 !the loads. Assuming that the loads have all just been energized 3 ~lin the sequence discussed, the first shed pulse will be applied 4 Ibecause of the blocked condition of NOR gate 33, since line D is 5 l'at one, to the equal priority group along line B. The restore 6 !Ipulse will turn off transfer memory 51 and turn off flip-flop 7 Icircuit 53 thereby energizing control relay 150 and disconnecting 8 Ijload 151 from the source. This also changes -transfer memory 61 9 and applies a zero to first output f of flip-flop circuit 63 for 10 ¦ receipt of the next shed signal. Upon receipt of the next shed signal flip-flop circuit 63 is turned off to disconnect load 161 12 from the source, change transfer memory 73 and to set up flip-flop 13 ¦circuit 73 for receipt of the next restore pulse.
14 ¦ If at this point, when loads 151 and 161 are disconnected in 15 , the sequence just described, a restore pulse would turn on flip-16 ~¦flop circuit 53 in control element 50 which has been enabled by 17 l¦the change of condition of transfer memory 52 upon the turning on 18 ¦of the load controlled by control element 60 during the restore 19 ,loperation. The sequencing follows in the same manner in both 20 Ished and restore operation by setting up the next control element 21 Ifor either a shed or restore operation. The first one on is 22 l¦always the first one turned off.
23 1 Upon receipt of the next shed pulse equal priority control 24 ,element 70 operates to disconnect load 171 from the source and 25 ¦ this changes the condition of the input along line D to the 26 ¦ control means since all the flip-flop circuits 53, 63 and 73 27 are turned off. This prevents further shed pulses from being 28 j applied to the equal priority group.
29 ~ The set priority group receives the next shed signal along 3 Illine A since NOR ga-te 33 is now enabled with line D being at zero.
311¦In control element 110 flip-flop circuit 116 is enabled for being 321 turned on because its first enabling input g is connected to . . ;~
~0~83~
1 jcommon connection Y, which is at zero, by switch 114, while the 2 llother Elip-flop clrcuits 126 and 136 are not ~nabled for turniny 3 ''on because their first enabling inputs g are connec-ted to the 4 ! first output of the preceeding flip-flop circuit, i.e., 126y to 5 1 136g -to 126e, which are at one.
6 l After flip-flop circuit 116 i5 turned, first enabling input g 7 of flip-flop circuit 126 is placed at zero and the next shed pulse 8 l¦will turn on flip-flop circuit 126 and connec-t load 221 to the 9 source. Similarly, a further shed pulse will operate on flip-flop circuit 136 which is now enabled for turning on and connect 11 load 231 to the source.
12 If a restore pulse appears, the last load in the se-t priority 13 l group to disconnect would be connected. In this manner the set 14 priority system connects the loads in a selected order of 15 ~ importance.
16 1 The use of empty socket 80 be-tween the two priority groups 17 l provides a means by which a plug-in system can use any number of 18 llcontrol elements in each priority group. In the set priority 19 1 control elements the appropriate common connection is made by 20 1 setting switches 113 and 114, 123 and 124 and 133 and 134 so 21 l¦that the star-t of the switching in the group can be established 22 1l for the shed and restore functions. The connections between the 23 llcontrol elements 110 and 120 are made through conductors llOB and 24 IllOV, between elements 120 and 130 through conductors 120s and 25 ~120V, and with corresponding conductors if additional control 26 lelements are used. It is only necessary to close switch 114 in 27 the first board and switch 133 in the last board with all the 28 corresponding switches in the intermediate boards set in an open 29 1 position.
3o ! The equal priority control elements use switches 58, 68 and 78 31 to make the proper backboard connections. It is only necessary 32jupon installation to close contacts,58a, 58b, 58c and 58d in the I
r- ~ l 1 ~06~3~4 ,j , 1 llfirst control element and close contacts 78e, 78f, 78g and 78h in 2 '~the las~ control element. The contacts in switches in any inter-3 llmediate boards, such as switch 68, are left open. The connections 4 ,Ibetween the adjacent control elements are made by conductors 50M, 5 j¦50N, 50Q and 50T and 60M, 60N, 60Q and 60T, corresponding to 6 ¦connections between other control elements if used.
7 lll .
8 ~I
~ I , o ~!
13 il 15 l 6 ll .
7,l ~
23 '1 2711 ,' 28 !
291 .
30ll . .
31 l~
Il -16- _
106~334 'I , 1 Ijrespective load is disconnected from the source. In this manner 2 ja failure of the demand controller system automatically connects 3 ,lall the loads to the source.
4 1 Referring to FIG. 4, equal priority control element 50 comprls~ !S
5 lltransfer memories 51 and 52, a flip-flop circuit 53, or gates 54 6 lland 55, reset switches 56 and 57, a multiple control switch 58, 7 1l and an inverting amplifier 59.
8 1l¦ Transfer memory 51, and the other similar transfer memories 9 I 52, 61, 62, 71 and 73, is a known device that produces a set of 10 ¦ complementary outputs and has a set input a, a reset input c, a 11 j control input b, a first output f and a first enabling input g 12 for the first output, and a second output e, which is the com-13 1 plement of the first output, and a second enabling input d for 14 ~ the second output. The set and reset inputs are controlling so 15 l that upon a set input, i.e., a one pulse, the first output will 16 Ibe changed to a one, thus switching the second output to a zero, 17 ~¦regardless of any of the conditions of the other inputs. Similarl~
18 1l upon a reset input of a one pulse the second output will be changet 19 Ito a one, and the first output to zero, regardless of any of the 20 ¦¦conditions of the other inputs. The enabling inputs control the 21 ~llmemory so that a change in the condition of the transfer memory 22 ¦will occur only if an enabling input and its corresponding output 23 l are at zero.
24 1 Flip-flop circuit 53, and the other similar flip-flop circuits 25 163 and 73, is a standard device known in the art that produces a 26 ¦set of complementary outputs and a first input a, a second input 27 I!b, a reset lnput c, a first output f, a first enabling input g, 28l a second output e, the complement of the first output, and a 29l second enabling input d. The circuit is of any -type known in the 30¦1art that changes the outputs only when a zero going pulse is 31¦~received at an input and the corresponding enabling input is at 32¦¦a zero. The output of flip-flop circuit 53 are applied to the Il Il _g _ ., , ~ , .. . . . . .: ..
~8 1 ,¦control means through OR gates 54 and 55, respectively, and to 2 llcontrol relay 150 through inverting amplifiex 59 along line 50C.
3 Reset switches 56 and 57 are positioned in the reset line and .
4 ¦idetermine the sequence for starting of the system. Switch 58 5 llmakes the appropriate return connections from the last to the 6 first control element through interconnecting conductors 103.
7 1 Equal priority control elements are interconnected through .
8 I'back connections 50' and 60'. Elements 60 and 70 are the same as 9 l¦control element 50 and corresponding last digits of identifying 10 Inumbers are used to indicate corresponding components.
Referring to FIG. 3, set priority control element, or board 12 ¦ 110, comprises a flip-flop circuit 116, OR gates 111 and 112, 13 connecting switches 113 and 114, and an inverting amplifier 115.
14 ¦Flip-flop circuit 116, and the corresponding flip-flop circuits .
15 1126 and 136 in the other control elements, is of the same type 16 ¦as flip-flop circuits 53, 63 and 73 in the equal priority control .
17 ¦elements and has a first input a, a second input b, a reset input 18 ¦Ic, a first output f, a first enabling input g, a second output e, 19 l¦the complement of the first output, and a second enabling input d.
20 ¦The outputs of flip-flop circuit 116 are applied to the control 21¦1means through OR gates 111 and 112, respectively, and to control 22 llrelay 210 through power inverter 115 along line 110C.
23 jl Set priority control elements 120 and 130 are the same as 24l control element 110 and corresponding last digits of identifying 25 numbers are used to indicate corresponding components. The set 26 priority control elements are interconnected through back con-27 l nections 110' and 120'. Switches 113 and 114, and corresponding .
28 1 switches in control elements 120 and 130, select the set priority 29 ¦ sequence.
3o I In the operation of the circuitry shown, upon initial energi-31 ¦zation of the demand controller and associated power system a .
32 ¦reset control 49 of any known type produces an initial pulse, I
~ .. ... ~
'- 106833~ , 1 I;going to one, along line X to each of the control elements. This 2 ! operates to disconnect all the loads so that the demand controller system can ~egin operating to restore the loads one by one until 4 ,~the selected restore signal level, or current, is exceeded. The 5 ll off or reset pulse is applied along line X to the transfer 6 l¦ memories in the equal priority control elements and to the flip-7 ¦flop circuits in all the control elements. For purposes of 8 Isimplifying the description the first output of any of the trans-~ Ifer memories or flip-flop circuits will be referred to in dis-10 l~cussing the state of the flip-flop circuits with an "on" condition 11 Ijmeaning that the first output is on, or in a one condition, and 12 l¦ the second output is off, or in a zero condition.
13 l The reset pulse along line X is applied through the reset 14 ¦ switches of each control element. In control element 50, switch 15 i 56 is open and switch 57 is closed to apply the pulse to set 16 1 input a of transfer memories 51 and 52 to turn them on. Control 17 il elements 60 and 70 have switches 66 and 67 and 76 and 77 positione( I
18 li oppositely to switches 56 and 57 and this applies the reset pulse l9ijto reset input c of transfer memories 61, 62, 71 and 72 to turn 20lithem off. The reset pulse is also applied to the reset inputs c 21 ¦ of flip-flop circuits 53, 63, 73, 116, 126 and 136 to turn them 22 1 off. This applies a zero input to the respective inverting 23 l amplifiers and a one input to the respective control relays. This 24 energizes the control relays to break the normally closed contacts 25 ~ and disconnect all the loads.
26 , Under the conditions occurring immediately after the reset 27 ! pulse with all the loads disconnected, the demand controller 28 system, after the selected time delay in the time delay means and 29 ¦if the current level of the loads is low enough, will produce a 3 restore pulse to control means 20 which will produce a one pulse 311 along line G. This occurs because lines E and F are at one (the 32j ff condition of the flip-flop circuits) and this blocks NOR gate ll ~, ,i _,____~ _ r . . .. .. . . . . ... .
l06a334 1 1144 and enables NOR gate 43 to respond to the restore pulse.
2 1¦ The pulse along line G is received by the set priority group, 3 l¦and received at the second input c of the flip-flop circuit.
4 ISwitches 113, 114, 123, 124, 133 and 134 in control elements 5 1 110, 120 and 130 are positioned so that the enabling input d of 6 only flip-flop circuit 136 is connected to a zero, or enabling, 7 ! point Y so that only flip-flop circuit 136 will respond to the 8 llpulse. The enabling inputs d of flip-flop circuits 116 and 126 9 l¦are connected to the second outputs e of flip-flop circuits 126 lO I and 136, respectively, which are at a one condition, through 11 ¦lines 110V and 120V, respectively and therefore are not enabled.
12 j The restore pulse therefore turns on flip-flop circuit 136 which 13 ~ de-energizes control relay 230 and connects load 231 to the load.
14 ~ The change in flip-flop circuit 136 changes input c of flip-flop 15 1 circuit 126 along line 120V from second output e of flip-flop 16 ! circuit 136.
17 ~ Upon occurrence of the next restore pulse after the selected 18 !linterval provided by the time delay means, if the current being 19~ drawn by the entire load system has not reached the selected 20 level, flip-flop circuit 126 will be turned on, load 221 will be 21 ,connected to the load, and the second enabling input d of flip-22 ¦flop circuit 116 will go to zero and be enabled. The next restore 23¦!pUlse similarly will turn on flip-flop circuit 116 and connect 241 load 211 to the source. This places all the set priority flip-25l flop circuits in an off condition which changes the condition of 26¦ line E to a zero thereby disabling NOR gate 43 and enabling NOR
27 ¦gate ~4 in the control means. Subsequent restore pulses will 28llSub5equently be applied to the equal priority group.
29l¦ The next restore pulse is applied along line H to the equal 3'priority group. The restore pulse is received by all three 311 flip-flop circuits 53, 63 and 73 in control elements 40, 60 and 32l 70' respectively as an input to their second inputs b. Flip-flop Il ~.
r-- ,-.
_, . . . . .
~833~
1 circuits 63 and 73 do not change because their second enabling 2 ¦inputs d are at a one condition since they are respectively con-3 1¦ nected to the second outputs e of transfer memories 62 and 72 4 l~which are in an off condition. Transfer memory 52, however, was 5 Iplaced in an on condition by the reset pulse which applies a zero 6 ¦!to enabling input d and enables the second output of flip-flop 7 1l circuit 53 which is accordingly turned on. First output f goes 8 I!to one and line 50C goes to zero to de-energize control relay 150 Y ~land connect load 151 to source 10.
lO I The restore pulses are also applied to input b of the restore transfer memories. Since transfer memory 52 has its second 12 ! enabling input at zero, from first output f of transfer memory 72 13 ll which is off, and its second output at zero, since it is turned 14 on, the restore pulse will turn off transfer memory 52. Similarly 15 lltransfer memory 62 has its first enabling input g and its first 16 '¦outPut f at zero and is turned on by the restore pulse. Transfer 17 ''~emory 72 remains in an off condition since its first enabling, 18 Ilinput g is one and its second output f is at one.
19 Upon the receipt of a second restore pulse, flip-flop circuit 20l 63 will be turned on to connect load 161 to the source. Transfer 211 memory 62 will change condition to change first enabling input d 22 'of flip-flop circuit 73 and thereby place flip-flop circuit 73 23 1l in an enabled condition for the receipt of the next restore pulse.
24,¦ Upon receipt of the next restore pulse flip-flop circuit 73 ' 25¦1is turned on to de-energize control relay 170 and connect load 171 26¦¦to the source.
27 llj Upon the change in output condition of flip-flop circuit 73 28llall the flip-flop circuits are turned on and the input along line 2gllto the control means is changed so that both NOR gates 43 and 44 3ol are in a blocked condition.
311 With the reverse operation of shedding loads, upon production 32 if a shed pulse, the control means and control elements operate !¦ -13-L ;
.... .
106833~ ~
l ¦¦in the same general manner in the reverse direction to disconnect 2 !the loads. Assuming that the loads have all just been energized 3 ~lin the sequence discussed, the first shed pulse will be applied 4 Ibecause of the blocked condition of NOR gate 33, since line D is 5 l'at one, to the equal priority group along line B. The restore 6 !Ipulse will turn off transfer memory 51 and turn off flip-flop 7 Icircuit 53 thereby energizing control relay 150 and disconnecting 8 Ijload 151 from the source. This also changes -transfer memory 61 9 and applies a zero to first output f of flip-flop circuit 63 for 10 ¦ receipt of the next shed signal. Upon receipt of the next shed signal flip-flop circuit 63 is turned off to disconnect load 161 12 from the source, change transfer memory 73 and to set up flip-flop 13 ¦circuit 73 for receipt of the next restore pulse.
14 ¦ If at this point, when loads 151 and 161 are disconnected in 15 , the sequence just described, a restore pulse would turn on flip-16 ~¦flop circuit 53 in control element 50 which has been enabled by 17 l¦the change of condition of transfer memory 52 upon the turning on 18 ¦of the load controlled by control element 60 during the restore 19 ,loperation. The sequencing follows in the same manner in both 20 Ished and restore operation by setting up the next control element 21 Ifor either a shed or restore operation. The first one on is 22 l¦always the first one turned off.
23 1 Upon receipt of the next shed pulse equal priority control 24 ,element 70 operates to disconnect load 171 from the source and 25 ¦ this changes the condition of the input along line D to the 26 ¦ control means since all the flip-flop circuits 53, 63 and 73 27 are turned off. This prevents further shed pulses from being 28 j applied to the equal priority group.
29 ~ The set priority group receives the next shed signal along 3 Illine A since NOR ga-te 33 is now enabled with line D being at zero.
311¦In control element 110 flip-flop circuit 116 is enabled for being 321 turned on because its first enabling input g is connected to . . ;~
~0~83~
1 jcommon connection Y, which is at zero, by switch 114, while the 2 llother Elip-flop clrcuits 126 and 136 are not ~nabled for turniny 3 ''on because their first enabling inputs g are connec-ted to the 4 ! first output of the preceeding flip-flop circuit, i.e., 126y to 5 1 136g -to 126e, which are at one.
6 l After flip-flop circuit 116 i5 turned, first enabling input g 7 of flip-flop circuit 126 is placed at zero and the next shed pulse 8 l¦will turn on flip-flop circuit 126 and connec-t load 221 to the 9 source. Similarly, a further shed pulse will operate on flip-flop circuit 136 which is now enabled for turning on and connect 11 load 231 to the source.
12 If a restore pulse appears, the last load in the se-t priority 13 l group to disconnect would be connected. In this manner the set 14 priority system connects the loads in a selected order of 15 ~ importance.
16 1 The use of empty socket 80 be-tween the two priority groups 17 l provides a means by which a plug-in system can use any number of 18 llcontrol elements in each priority group. In the set priority 19 1 control elements the appropriate common connection is made by 20 1 setting switches 113 and 114, 123 and 124 and 133 and 134 so 21 l¦that the star-t of the switching in the group can be established 22 1l for the shed and restore functions. The connections between the 23 llcontrol elements 110 and 120 are made through conductors llOB and 24 IllOV, between elements 120 and 130 through conductors 120s and 25 ~120V, and with corresponding conductors if additional control 26 lelements are used. It is only necessary to close switch 114 in 27 the first board and switch 133 in the last board with all the 28 corresponding switches in the intermediate boards set in an open 29 1 position.
3o ! The equal priority control elements use switches 58, 68 and 78 31 to make the proper backboard connections. It is only necessary 32jupon installation to close contacts,58a, 58b, 58c and 58d in the I
r- ~ l 1 ~06~3~4 ,j , 1 llfirst control element and close contacts 78e, 78f, 78g and 78h in 2 '~the las~ control element. The contacts in switches in any inter-3 llmediate boards, such as switch 68, are left open. The connections 4 ,Ibetween the adjacent control elements are made by conductors 50M, 5 j¦50N, 50Q and 50T and 60M, 60N, 60Q and 60T, corresponding to 6 ¦connections between other control elements if used.
7 lll .
8 ~I
~ I , o ~!
13 il 15 l 6 ll .
7,l ~
23 '1 2711 ,' 28 !
291 .
30ll . .
31 l~
Il -16- _
Claims (7)
1. A demand controller for an electrical power system of the type connecting and disconnecting electrical loads from an electri-cal source to control the level of electrical power consumption comprising:
a sensing means responsive to the current in the power system for producing a first output signal when the current is above a first preselected level for a preselected time and a second output signal when the current is below a second pre-selected level for a preselected time;
a first group of control elements each connected to respectively control each of a first group of loads and having a means responsive to control signals for connecting and discon-necting its loads in a preselected first priority sequence;
a second group of control elements each connected to respectively control each of a second group of loads and having a means responsive to control signals for connecting and discon-necting its loads in a preselected second priority sequence; and a control means responsive to the first output signal and the second output signal for producing for selectively delivering control signals to the first and second group of control elements in a preselected sequence.
a sensing means responsive to the current in the power system for producing a first output signal when the current is above a first preselected level for a preselected time and a second output signal when the current is below a second pre-selected level for a preselected time;
a first group of control elements each connected to respectively control each of a first group of loads and having a means responsive to control signals for connecting and discon-necting its loads in a preselected first priority sequence;
a second group of control elements each connected to respectively control each of a second group of loads and having a means responsive to control signals for connecting and discon-necting its loads in a preselected second priority sequence; and a control means responsive to the first output signal and the second output signal for producing for selectively delivering control signals to the first and second group of control elements in a preselected sequence.
2. A demand controller according to claim 1 wherein said control elements are plug-in modular units and have a means for electrically connecting to an interconnecting electrical network.
3. A demand controller according to claim 2 wherein each of said control elements comprises a multiple connector switch connected to selectively change the connections to the inter-connecting electrical network to provide selective connections between control elements in each priority group.
4. A demand controller according to claim 1 wherein said sensing means comprises a means for measuring the current in the power system to produce an output proportional to the current in the power system, a comparing means responsive to the measuring means output for producing a first signal when the measuring means output is above a first preselected level and for producing a second signal when it is below a second preselected level; and a time delay means responsive to the first and second signals for producing a corresponding first output signal and a second output signal in response to the receipt of the first signal and the second signal, respectively, after a preselected time interval.
5. A demand controller according to claim 1 wherein said control elements each have a means responsive to the receipt of an appropriate control signal for connecting or disconnecting its corresponding load and for producing an output for at least one other control element of the same group, and each have a means responsive to said control element outputs for changing conditions in preparation for receipt of a control signal.
6. A demand controller according to claim 5, wherein said control elements each have a means responsive to the receipt of an appropriate control signal for connecting or disconnecting its corresponding load and for producing one output for at least one other control element of the same group.
7. A demand controller for an electrical power system of the type connecting and disconnecting electrical loads from an electri-cal source to control the level of electrical power consumption comprising:
a means for measuring the current in the power system to produce an output varying as a function of the current;
a comparing means responsive to the measuring means out-put for producing a first signal when the measuring means output is above a first preselected level and a second signal when the measuring means output is below a second preselected level;
a time delay means responsive to the first and second signals for producing a corresponding shed signal and a restore signal in response to the receipt of the first signal and the second signal respectively after a preselected time interval;
a group of equal priority control elements each connected to respectively control each of a first group of loads and each having a means for producing an output indicating the connection or disconnection of its corresponding load and said group having a means responsive to shed control signals for disconnecting the first group of loads in an equal priority sequence and to restore control signals for connecting the first group of loads in an equal priority sequence;
a group of set priority control elements each connected to respectively control a second group of loads and each having a means for producing an output indicating the connection or dis-connection of its corresponding load, said group having a means responsive to shed control signals for disconnecting the second group loads in a set priority sequence and responsive to restore control signals for connecting the second group of loads in a set priority sequence; and a control means responsive to the shed signal and the restore signal for producing corresponding shed control signals and restore control signals and for selectively delivering the control signals to the two groups of control elements in a pre-selected sequence.
a means for measuring the current in the power system to produce an output varying as a function of the current;
a comparing means responsive to the measuring means out-put for producing a first signal when the measuring means output is above a first preselected level and a second signal when the measuring means output is below a second preselected level;
a time delay means responsive to the first and second signals for producing a corresponding shed signal and a restore signal in response to the receipt of the first signal and the second signal respectively after a preselected time interval;
a group of equal priority control elements each connected to respectively control each of a first group of loads and each having a means for producing an output indicating the connection or disconnection of its corresponding load and said group having a means responsive to shed control signals for disconnecting the first group of loads in an equal priority sequence and to restore control signals for connecting the first group of loads in an equal priority sequence;
a group of set priority control elements each connected to respectively control a second group of loads and each having a means for producing an output indicating the connection or dis-connection of its corresponding load, said group having a means responsive to shed control signals for disconnecting the second group loads in a set priority sequence and responsive to restore control signals for connecting the second group of loads in a set priority sequence; and a control means responsive to the shed signal and the restore signal for producing corresponding shed control signals and restore control signals and for selectively delivering the control signals to the two groups of control elements in a pre-selected sequence.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US05/665,655 US4100426A (en) | 1976-03-10 | 1976-03-10 | Load controlling means |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1068334A true CA1068334A (en) | 1979-12-18 |
Family
ID=24671006
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA272,343A Expired CA1068334A (en) | 1976-03-10 | 1977-02-22 | Load controlling means |
Country Status (5)
| Country | Link |
|---|---|
| US (1) | US4100426A (en) |
| AU (1) | AU509433B2 (en) |
| CA (1) | CA1068334A (en) |
| GB (1) | GB1579042A (en) |
| MX (1) | MX143053A (en) |
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| US4168491A (en) * | 1977-09-29 | 1979-09-18 | Phillips Control Corp. | Energy demand controller and method therefor |
| US4228364A (en) * | 1978-06-05 | 1980-10-14 | Walden Jack O | Energy management system |
| US4177388A (en) * | 1978-07-10 | 1979-12-04 | Louise D. Suhey | Programmable control for load management |
| US4228511A (en) * | 1978-10-06 | 1980-10-14 | General Electric Company | System and method of power demand limiting and temperature control |
| US4272012A (en) * | 1979-03-09 | 1981-06-09 | Molnar John R | Method and system for controlling a plurality of temperature conditioning units |
| GB2080640B (en) * | 1980-07-14 | 1983-12-07 | South Eastern Elec Board | Power supply systems |
| US4419589A (en) * | 1982-06-14 | 1983-12-06 | Ross James W | Multi-stage electrical control system |
| US4506516A (en) * | 1984-04-06 | 1985-03-26 | Carrier Corporation | Refrigeration unit compressor control |
| US4694192A (en) * | 1984-11-23 | 1987-09-15 | Honeywell Inc. | Simplified demand limit control |
| US4663539A (en) * | 1984-11-29 | 1987-05-05 | Burroughs Corporation | Local power switching control subsystem |
| US4786799A (en) * | 1987-07-27 | 1988-11-22 | General Electric Company | Power control for cooking appliance with multiple heating units |
| JP2770446B2 (en) * | 1989-07-20 | 1998-07-02 | 富士通株式会社 | Redundant power supply startup method |
| US5384712A (en) * | 1991-08-15 | 1995-01-24 | Eaton Corporation | Energy monitoring system for a plurality of local stations with snapshot polling from a central station |
| US5315531A (en) * | 1991-08-15 | 1994-05-24 | Westinghouse Electric Corp. | Energy monitoring system for a plurality of local stations with snapshot polling from a central station |
| FR2721449B1 (en) * | 1994-06-16 | 1996-08-02 | Schneider Electric Sa | Device for managing the electrical power of an installation. |
| IT1274542B (en) * | 1995-05-22 | 1997-07-17 | Bticino Spa | DEVICE TO SET THE PRIORITY OF AN ELECTRIC SOCKET |
| US6086397A (en) * | 1998-04-27 | 2000-07-11 | American Express Travel Related Services Company, Inc. | High reliability raised floor power strip |
| US6160320A (en) * | 1999-08-04 | 2000-12-12 | Yang; Chung-Chin | Load control method by detecting the time state of same frequency alternating current sine wave and alternating current square wave |
| US6940272B2 (en) * | 2002-10-10 | 2005-09-06 | Green Socket Ltd. | Electric socket control device |
| IL152486A0 (en) | 2002-10-25 | 2003-05-29 | Meir Eini | Alcohol-free cosmetic and pharmaceutical foam carrier |
| WO2004037225A2 (en) | 2002-10-25 | 2004-05-06 | Foamix Ltd. | Cosmetic and pharmaceutical foam |
| US10117812B2 (en) | 2002-10-25 | 2018-11-06 | Foamix Pharmaceuticals Ltd. | Foamable composition combining a polar solvent and a hydrophobic carrier |
| US8119150B2 (en) | 2002-10-25 | 2012-02-21 | Foamix Ltd. | Non-flammable insecticide composition and uses thereof |
| US8486376B2 (en) | 2002-10-25 | 2013-07-16 | Foamix Ltd. | Moisturizing foam containing lanolin |
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| US9668972B2 (en) | 2002-10-25 | 2017-06-06 | Foamix Pharmaceuticals Ltd. | Nonsteroidal immunomodulating kit and composition and uses thereof |
| US8119109B2 (en) | 2002-10-25 | 2012-02-21 | Foamix Ltd. | Foamable compositions, kits and methods for hyperhidrosis |
| US20040166085A1 (en) * | 2003-02-21 | 2004-08-26 | Gurusamy Manivannan | Shave gel compositions |
| US8795693B2 (en) | 2003-08-04 | 2014-08-05 | Foamix Ltd. | Compositions with modulating agents |
| US8486374B2 (en) | 2003-08-04 | 2013-07-16 | Foamix Ltd. | Hydrophilic, non-aqueous pharmaceutical carriers and compositions and uses |
| FR2879853A1 (en) * | 2004-12-21 | 2006-06-23 | Epiq | Power distribution device for domestic electric heating system, has control unit controlling distribution unit distributing power to heaters based on cyclic sequence, where power is distributed at center of time segment of sequence |
| US7741732B2 (en) * | 2006-09-14 | 2010-06-22 | Lutron Electronics Co., Inc. | Method of configuring a startup sequence of a load control system |
| US7781919B2 (en) * | 2006-09-14 | 2010-08-24 | Lutron Electronics Co., Inc. | Method of controlling a load control module as part of a startup sequence |
| US20110049984A1 (en) * | 2009-08-27 | 2011-03-03 | Electronics And Telecommunications Research Institute | Power-consumption control apparatus and method for smart meter |
| WO2011039638A2 (en) | 2009-10-02 | 2011-04-07 | Foamix Ltd. | Topical tetracycline compositions |
| US9125010B2 (en) * | 2011-10-27 | 2015-09-01 | General Electric Company | Systems and methods to implement demand response events |
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| JP6698823B2 (en) * | 2016-04-15 | 2020-05-27 | 三菱電機株式会社 | Air conditioner and transmission line abnormality detection method |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CA843617A (en) * | 1970-06-02 | Theodore Wildi | Load-control and power-distributing system | |
| US3339079A (en) * | 1964-07-01 | 1967-08-29 | Westinghouse Electric Corp | Load demand program control |
| SE337137B (en) * | 1967-02-21 | 1971-07-26 | Atlas Copco Ab | |
| US3439181A (en) * | 1967-03-10 | 1969-04-15 | Weston Instruments Inc | Dual set point solid state relay |
| US3529173A (en) * | 1968-02-05 | 1970-09-15 | Weil Mclain Co Inc | Incremental modulating controller for electrical apparatus |
| US3538391A (en) * | 1968-06-28 | 1970-11-03 | Singer Co | Electrical load control systems |
| US3588518A (en) * | 1969-02-13 | 1971-06-28 | Westinghouse Electric Corp | Power multiplexing system |
| US3787729A (en) * | 1972-07-13 | 1974-01-22 | Cam Ind Inc | Sequencing step control |
| US3881114A (en) * | 1973-09-11 | 1975-04-29 | Rodolfo D Ferrari | Electronic sequencer |
-
1976
- 1976-03-10 US US05/665,655 patent/US4100426A/en not_active Expired - Lifetime
-
1977
- 1977-02-22 CA CA272,343A patent/CA1068334A/en not_active Expired
- 1977-02-28 GB GB8304/77A patent/GB1579042A/en not_active Expired
- 1977-03-03 AU AU22895/77A patent/AU509433B2/en not_active Expired
- 1977-03-09 MX MX168303A patent/MX143053A/en unknown
Also Published As
| Publication number | Publication date |
|---|---|
| US4100426A (en) | 1978-07-11 |
| AU2289577A (en) | 1978-09-07 |
| MX143053A (en) | 1981-03-02 |
| GB1579042A (en) | 1980-11-12 |
| AU509433B2 (en) | 1980-05-15 |
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