Demand control apparatus and power distribution control system

• US 5,481,140 A
• Filed: 03/04/1993
• Issued: 01/02/1996
• Est. Priority Date: 03/10/1992
• Status: Expired due to Fees

• Current Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Kushiro, Noriyuki, Inoue, Masahiro, Maruyama, Kazuhiro, Iwatsubo, Rieko
• Primary Examiner(s): Shoop, Jr., William M.
• Assistant Examiner(s): PALADINI, ALBERT WILLIAM
• Application Number:
  US08/026,552
• Time in Patent Office: 1,034 Days
• Field of Search: 307/35, 307/38, 307/39, 307/40, 307/85, 307/11, 364/492
• US Class Current: 307/11
• CPC Class Codes: H02J 13/00004 characterised by the power network being locally controlled
• CPC Class Codes: H02J 13/00016 using a wired telecommunication network or a data transmission bus
• CPC Class Codes: H02J 2310/12 The local stationary network supplying a household or a building
• CPC Class Codes: H02J 2310/64 The condition being economic, e.g. tariff based load management
• 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: Y02B 90/20 Smart grids as enabling technology in buildings sector smart grids supporting the management or operation of end-user stationary applications in general, or like technologies with no associated climate change mitigation effect Y04S20/00
• CPC Class Codes: Y02P 80/10 Efficient use of energy, e.g. using compressed air or pressurized fluid as energy carrier
• CPC Class Codes: Y04S 20/222 Demand response systems, e.g. load shedding, peak shaving
• CPC Class Codes: Y04S 40/124 using wired telecommunication networks or data transmission busses
• CPC Class Codes: Y04S 50/10 Energy trading, including energy flowing from end-user application to grid

Abstract

The present invention relates to a power distribution control system for suppressing a total quantity of working current in a group of loads to a level equal to or lower than a set quantity of current by controlling the loads. The power distribution control system includes a central communication terminal and a plurality of customer communication terminals connected to the center communication terminal through communication lines. Each of the customer communication terminals is responsive to a presentation signal from the center communication terminal that requests time periods for, and quantities of power reduction. The central communication terminal also provides a response signal to selected customer communication terminals. The response signal indicates that a proposal for power reduction by the customer has been accepted.

Claims

1. A demand control apparatus connected to a group of loads and adapted to shut off a power supply to loads in accordance with set priority levels so that a total quantity of working current in the group of loads will be equal to or lower than a set quantity of current, said apparatus comprising:

power detecting means for computing a quantity of working current in each of the loads from a difference in the total quantity of working current before and after shutoff of the power supply to each of said loads; and

restart control means for comparing the quantity of working current in each of said loads with a difference between the set quantity of current and the total quantity of working current at a present time in accordance with information of the quantity of working current in each of the loads detected by said power detecting means, and for controlling the restart of one or more loads in accordance with the set priority levels of the loads and said difference between the set quantity of current and the total quantity of working current at the present time.

2. A demand control apparatus connected to a group of loads and adapted to shut off a power supply to loads in accordance with set priority levels so that a total quantity of working current in the group of loads will be equal to or lower than a set quantity of current, said apparatus comprising:

registration means for registering and storing a quantity of working current for each of said loads; and

shutoff control means for comparing the quantity of working current for each of the loads with the set quantity of current when the total quantity of working current exceeds the set quantity of current, and for selecting one or more of the loads to be in an on state, each of the selected loads having a quantity of working current equal to or lower than the set quantity of current and a sum of the total quantity of working current of the selected loads being equal to or lower than the set quantity of current, the selected loads being selected in accordance with the set priority levels of said selected loads, said shutoff control means being also adapted to turn all loads other than said selected loads off.

3. A demand control apparatus connected to a group of loads so that a total quantity of working current in the group of loads can be equal to or lower than a set quantity of current, said apparatus comprising:

receiving means for receiving a power usage request from each of said loads; and

demand control means for responding to the power usage request and for outputting a signal including a possible quantity of working current to the load which has provided the power usage request.

4. A demand control apparatus connected to a group of loads and adapted to shut off a power supply to loads in accordance with set priority levels so that a total quantity of working current in the group of loads will be equal to or lower than a set quantity of current, said apparatus comprising:

a setting section; and

a control section;

wherein said setting section includes;

load selecting means for selecting one or more loads to be controlled from the group of loads, and for specifying priority levels of the selected loads; and

power level setting means for setting a target power level for load control; and

wherein said control section includes;

memory means for storing the selected loads selected by said load selecting means, the priority levels of the selected loads and the target power level set by said power level setting means;

comparator means for comparing the target power level stored in the memory means with the total quantity of working current;

power supply shutoff means for shutting off the power supply to the selected loads in accordance with the priority levels of the selected loads stored in the memory means; and

load control discontinuing means for discontinuing load control when the total quantity of working current exceeds the target power level after shutting off the power supply to the selected loads.

5. A demand control apparatus as defined in claim 4, further comprising an external instrument connected to said demand control apparatus and wherein said control section further comprises external request executing means responsive to a control request signal from said external instrument for executing the control request signal when the selection of loads, the priority levels and the target power level have been stored.

6. A demand control apparatus as defined in claim 4 wherein said control section further comprises changing means for changing the target power level and also outputting the changed target power level to said setting section when the total quantity of working current still exceeds the target power level after shut-off by said power supply shut-off means.

7. A demand control apparatus as defined in claim 6, further comprising an external instrument connected to said demand control apparatus and wherein said control section further comprises external request executing means responsive to a control request signal from said external instrument for executing the control request signal when the selection of loads, the priority levels and the target power level have been stored, and changed level signal outputting means for outputting a signal containing the changed target power level to said external instrument when the target power level has been changed.

8. A demand control apparatus as defined in claim 4, further comprising an external instrument connected to said demand control apparatus and wherein said control section further includes external request executing means responsive to a control request signal from said external instrument for responding to the control request signal to provide data regarding the selection of loads, the priority levels and the target power level, and a discontinuation signal outputting means for providing a discontinuation signal to the external instrument that indicates the discontinuation of load control.

9. A demand control apparatus connected to a group of loads so that a total quantity of working current in the group of loads can be suppressed to be equal to or lower than a set quantity of current, said apparatus comprising:

an operating section;

a data base section; and

a control section;

wherein said operating section includes;

selection means for selecting one or more loads to be controlled from the group of loads; and

time setting means for setting information of operation initiating times and

operation terminating times in each of said selected loads;

wherein said data base section stores data relating to a quantity of working current of each of the loads, a quantity of working current for each function of each of the loads, a standard operation time of each of the loads, a priority level for each of the loads and the set quantity of current; and

wherein said control section includes control means for controlling the total quantity of working current to a level equal to or lower than the set quantity of current by shifting the operation terminating times of each of the selected loads to be controlled in accordance with its priority level when the total quantity of working current exceeds the set quantity of current at any time where said selected loads are operating.

10. A power distribution control system comprising:

a center communication terminal; and

a plurality of customer'"'"'s communication terminals operatively connected to said center communication terminal through communication lines, each customer'"'"'s communication terminal being connected to a plurality of corresponding loads;

said center communication terminal including;

presentation signal outputting means for outputting a presentation signal containing a load reduction request time period and an incentive payment to each of said customer'"'"'s communication terminals; and

selection signal outputting means responsive to response signals from said customer'"'"'s communication terminals for outputting at least one selection signal to one or more customer'"'"'s communication terminals based on parameters relating to a reduced quantity of power and a reduction time period in the response signals; and

each of said customer'"'"'s communication terminals including;

response signal outputting means for outputting a response signal to said center communication terminal, said response signal containing the reduced quantity of power and the reduction time period, wherein, the reduced quantity of power and the reduction time period are computed from the load reduction request time period, and the incentive payment contained in the presentation signal from said center communication terminal, and one or more potentials of reduction; and

power reduction means for reducing a power supply to the corresponding plurality of loads for a given time period, based on the selection signal from said center communication terminal.

11. A power distribution control system as defined in claim 10 wherein said selection signal outputting means of the center communication terminal is adapted to output a selection signal containing the reduction time period, the reduced quantity of power and the incentive payment which are computed from the reduced quantity of power and the reduction time period in the response signal from each of said customer'"'"'s communication terminals.

12. A power distribution control system as defined in claim 11, wherein said center communication terminal further includes:

predicted demand computing means for computing a predicted demand from a demand predicting potential;

price determining means for comparing said predicted demand with a power supply capacity to determine an electric power price; and

price signal outputting means for outputting a power price signal containing the determined power price to each of said customer'"'"'s communication terminals.

13. A power distribution control system as defined in claim 10, wherein said center communication terminal further includes:

predicted demand computing means for computing a predicted demand from a demand predicting potential;

price determining means for comparing said predicted demand with a power supply capacity to determine an electric power price; and

price signal outputting means for outputting a power price signal containing the determined power price to each of said customer'"'"'s communication terminals.

14. A power distribution control system comprising:

a center communication terminal; and

a plurality of customer'"'"'s communication terminals operatively connected to said center communication terminal through communication lines, each customer'"'"'s communication terminal being connected to a corresponding plurality of loads;

said center communication terminal including;

presentation signal outputting means for outputting a presentation signal containing a load reduction request time period and an incentive payment to each of said customer'"'"'s communication terminals; and

selection signal outputting means responsive to response signals from said customer'"'"'s communication terminals for outputting at least one selection signal to one or more customer'"'"'s communication terminals based on a product of a reduced quantity of power and a reduction time period in the response signals,

each of said customer'"'"'s communication terminals including;

response signal outputting means for outputting a response signal to said center communication terminal, said response signal containing the reduced quantity of power and the reduction time period, wherein, the reduced quantity of power and reduction time period are computed from the load reduction request time period, the incentive payment, and one or more reduction potentials; and

power reduction means for reducing a power supply to the corresponding plurality of loads for a given time period, based on the selection signal from said center communication terminal.

15. A power distribution control system as defined in claim 14 wherein said selection signal outputting means of the center communication terminal is adapted to output a selection signal containing the reduction time period, the reduced quantity of power and the incentive payment which are computed from the reduced quantity of power and the reduction time period in the response signal from each of said customer'"'"'s communication terminals.

16. A power distribution control system as defined in claim 15, wherein said center communication terminal further includes:

predicted demand computing means for computing a predicted demand from a demand predicting potential;

price determining means for comparing said predicted demand with a power supply capacity to determine an electric power price; and

price signal outputting means for outputting a power price signal containing the determined power price to each of said customer'"'"'s communication terminals.

17. A power distribution control system as defined in claim 14, wherein said center communication terminal further includes;

predicted demand computing means for computing a predicted demand from a demand predicting potential;

price determining means for comparing said predicted demand with a power supply capacity to determine an electric power price; and

price signal outputting means for outputting a power price signal containing the determined power price to each of said customer'"'"'s communication terminals.

18. A power distribution control system comprising:

a center communication terminal; and

a plurality of customer'"'"'s communication terminals operatively connected to said center communication terminal through communication lines, each customer'"'"'s communication terminal being connected to a corresponding plurality of loads;

said center communication terminal including;

presentation signal outputting means for outputting a presentation signal containing a load reduction request time period to each of said customer'"'"'s communication terminals; and

selection signal outputting means responsive to response signals from said customer'"'"'s communication terminals for outputting at least one selection signal to one or more customer'"'"'s communication terminals each of which has a reduced incentive payment; and

each of said customer'"'"'s communication terminals including;

response signal outputting means for outputting a response signal to said center communication terminal, said response signal containing an incentive payment computed from the load reduction request time period contained in the presentation signal and a plurality of reduction potentials; and

power reduction means for reducing a power supply to the corresponding plurality of loads for a given time period, based on the selection signal from said center communication terminal.

19. A power distribution control system as defined in claim 18, wherein said center communication terminal further includes:

predicted demand computing means for computing a predicted demand from a demand predicting potential;

price determining means for comparing said predicted demand with a power supply capacity to determine an electric power price; and

price signal outputting means for outputting a power price signal containing the determined power price to each of said customer'"'"'s communication terminals.

20. A power distribution control system comprising:

a center communication terminal; and

a plurality of customer'"'"'s communication terminals operatively connected to said center communication terminal through communication lines, each customer'"'"'s communication terminal being connected to a corresponding plurality of loads;

said center communication terminal including;

presentation signal outputting means for outputting a presentation signal containing a load reduction request time period; and

selection signal outputting means responsive to response signals from said customer'"'"'s communication terminals for outputting at least one selection signal to one or more customer'"'"'s communication terminals based on parameters relating to a reduced quantity of power, a reduction time period and an incentive payment;

each of said customer'"'"'s communication terminals including;

response signal outputting means for outputting a response signal to said center communication terminal, said response signal containing the reduced quantity of power, the reduction time period and the incentive payment, each of which are computed from the load reduction request time period contained in the presentation signal from said center communication terminal, and one or more reduction potential; and

power reduction means for reducing a power supply to the corresponding plurality of loads for a given time period, based on the selection signal from said center communication terminal.

21. A power distribution control system as defined in claim 20, wherein said center communication terminal further includes:

predicted demand computing means for computing a predicted demand from a demand predicting potential;

price determining means for comparing said predicted demand with a power supply capacity to determine an electric power price; and

price signal outputting means for outputting a power price signal containing the determined power price to each of said customer'"'"'s communication terminals.

22. A power distribution control system comprising:

a center communication terminal; and

a plurality of customer'"'"'s communication terminals operatively connected to said center communication terminal through communication lines, each customer'"'"'s communication terminal being connected to a corresponding plurality of loads;

said center communication terminal including;

predicted demand computing means for computing a predicted demand from a demand predicting potential;

price determining means for comparing said predicted demand with a power supply capacity to determine an electric power price; and

price signal outputting means for outputting a power price signal containing a determined power price to each of said customer'"'"'s communication terminals.

23. A power distribution control system comprising:

a central communication terminal including;

means tier outputting a request signal containing a first set of power reduction parameters including cost savings incentives;

means for receiving a response signal; and

means for outputting a selection signal, containing a third set of power reduction parameters, to customers selected for power reduction; and

a plurality of customer communication terminals coupled to the central communication terminal and to a corresponding plurality of loads powered from a power distribution system, each customer communication terminal including;

means for receiving the request signal from the central communication terminal;

means for computing a second set of power reduction parameters based on the first set of power reduction parameters;

means for outputting a response signal to the central communication terminal, the response signal containing the second set of power reduction parameters; and

power reduction means for reducing power to the corresponding plurality of loads based on the third set of power reduction parameters received from the central communication terminal.

24. The power distribution system of claim 23 wherein:

the first set of parameters includes a requested time period of power reduction;

the second set of parameters includes a proposed time period of power reduction, and a proposed quantity of power reduction.

25. The power distribution system of claim 24 wherein the selection means of the central communication terminal selects customers based upon a product of the proposed time period of power reduction and the proposed quantity of power reduction contained in each response signal.

26. The power distribution system of claim 23, wherein the third set of parameters includes a reduction time period, a reduced quantity of power, and a cost savings incentive.

27. The power distribution system of claim 23, wherein:

the second set of parameters includes a proposed cost savings incentive; and

the selection means selects a customer based upon the proposed cost savings incentive contained in each response signal.

28. The power distribution control system of claim 23, wherein the central communication terminal further includes predicted demand computing means for computing a predicted demand, and price determining means for comparing said predicted demand with a power supply capacity to determine an electric power price;

and

wherein the first set of parameters includes the electric power price.

29. A method for controlling power in a power distribution system comprising steps of:

A. sending a power reduction request for power reduction from a central control terminal to a plurality of customer sites, the request including cost savings incentives;

B. receiving proposals for power reduction from each customer site; and

C. selecting one or more of the proposals received from the customers.

30. The method of claim 29, wherein the request to each customer includes a time period for power reduction, and a quantity of power reduction.

31. The method of claim 29, wherein each proposal includes a time period for power reduction and a quantity of power reduction.

32. The method of claim 29, wherein each proposal includes a cost incentive proposal, and wherein the selecting of one or more of the proposals is based on cost.

33. The method of claim 29, further including an initial step of predicting future power demands, and wherein the request for power reduction of step A is based on a prediction generated by the step of predicting future power demand.