System for controlling power distribution to customer loads

• US 4,348,668 A
• Filed: 07/02/1979
• Issued: 09/07/1982
• Est. Priority Date: 07/02/1979
• Status: Expired due to Term

• Current Assignee: Sangamo Weston, Inc. (Atos SE)
• Original Assignee: Sangamo Weston, Inc. (Atos SE)
• Inventors: Nelson, Bruce J., Gurr, George P.
• Primary Examiner(s): YUSKO, DONALD
• Application Number:
  US06/053,710
• Time in Patent Office: 1,163 Days
• Field of Search: 340/147 R, 340/147 P, 340/310 R, 340/310 A, 340/825.06, 364/492, 364/493, 307/39
• US Class Current: 340/3.32
• CPC Class Codes: H02J 13/00007 using the power network as support for the transmission
• CPC Class Codes: H02J 13/00034 the elements or equipment being or involving an electric power substation
• CPC Class Codes: H02J 2310/60 Limiting power consumption in the network or in one section of the network, e.g. load shedding or peak shaving
• CPC Class Codes: H02J 3/144 Demand-response operation of the power transmission or distribution network
• CPC Class Codes: Y02B 70/3225 Demand response systems, e.g. load shedding, peak shaving
• CPC Class Codes: 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: Y04S 20/222 Demand response systems, e.g. load shedding, peak shaving
• CPC Class Codes: Y04S 40/121 using the power network as support for the transmission

Abstract

A method and apparatus which permits a power utility to have direct control of customers loads (CD) with a view toward facilitating enablement of a load management philosophy which includes peak shaving and load deferral. A master control station (MCS), which comprises a programmable microprocessor-based central controller, is in two-way communication with a plurality of substation injection units (SIU), one of each of which is positioned at a separate substation of the power utility. Each substation injection unit (SIU), under the control of its own microprocessor, responds to master control signals from the master control station (MCS) to inject a pulse code signal onto the power lines of the utility. The system includes a plurality of remote receiver units (RRU) which are positioned at and connected to control the on and off times of customer loads (CD). Each remote receiver unit (RRU) is preset to respond to particular pulse code signals from the substation injection units (SIU) to carry out the desired command functions, which can be implemented either automatically or manually on a fixed or dynamic-cycle basis as the need arises. The system utilizes a command signal and pulse code signal verification technique to insure system integrity and reliability.

Claims

1. A method for regulating a plurality of loads connected by power lines of an electric power utility to a remote utility station, said utility station having an electronic digital computer for controlling communications to the loads, said loads being classified into load control groups, each of said groups being responsive to at least one of a plurality of group control command signals for causing the loads in the respective group to be turned on or off, which comprises the steps of:

(a) storing in the computer at the station preselected first, second and third types of control lists, each of said lists including at least one group control command;

(b) selecting one of said control lists for activation and then executing the respective group control commands in the selected list as follows;

(i) upon selecting said first type of control list, executing each group control command therein only once;

(ii) upon selecting said second or said third type of control lists, executing each group control command therein repetitively;

(c) generating a group control command signal in response to the execution of each of said group control commands;

(d) transmitting said group control command signal through said power lines to said loads to effect turning on or off of said loads; and

(e) periodically adjusting the duty cycle of the loads in those of said load control groups appearing on said third type of control list in accordance with the power demand on said utility, wherein said step of periodically adjusting includes the steps of;

(i) selecting the maximum off interval MO per time cycle and the minimum off interval per time cycle desired for loads in each of said groups classified in said third type of control list;

(ii) monitoring the total power demand X on said utility;

(iii) selecting a minimum value AV and a maximum value MV for the total power demand which correspond respectively to said minimum and maximum off intervals; and

(iv) adjusting the actual off interval Y of said loads according to the following formula;

space="preserve" listing-type="equation">Y=(MO)((X-AV)/(MV-AV).

2. The method of claim 1, further comprising the step of prioritizing the transmission of the group control command signals to said loads in accordance with the priority of the corresponding control list from which the command signal was generated.

3. The method of claim 1, further comprising the step of recording the group control commands on an archival tape module at the station for recordkeeping purposes.

4. The method of claim 1, further comprising, prior to the step of executing the respective group control commands, the step of checking to see whether the selected control list has been preapproved to run on that particular day at that particular time.

5. The method of claim 1, further comprising, prior to the step of transmitting said group control command signal, the step of eliminating any duplicate group control command signals by:

identifying the oldest group control command signal; and

combining the oldest group control command signal with like group control command signals.