Digital load control circuit and method for power monitoring and limiting system
First Claim
1. A circuit for controlling the the "on/off" states of each of a plurality of electrical loads in response to power monitoring and signal generating circuit means that monitors the electrical power delivered to the "on" loads and produces an add control signal commanding the addition of one or more of the loads when power consumption is to be increased and produces a shed control signal commanding the shedding of one or more of said plurality of loads when such power consumption is to be decreased, comprising:
- a plurality of individually addressable load control latch means, each having a load-off state and a load-on state, said plurality of load control latch means having a common data input means to which each of said load control latch means is individually responsive when it is addressed, each of said plurality of loads being adapted for control by a separate one of said load control latch means so that when each of said latch means is in its load-off state the load controlled thereby is "off", and when each of said latch means is in its load-on state, the load controlled thereby is "on";
address generating means for generating a succession of address signals, each such signal being effective to address a separate one of said plurality of load control latch means;
multiplexing means responsive to said succession of address signals produced by said address generator means so as to be synchronously operated with the addressing of said load control latch means, said multiplexing means having a plurality of inputs each of which is connected to a separate one of said plurality of load control latch means, said multiplexing means having a common output at which a signal is produced indicating the state of that one of said load control latch means then being addressed by said counter means;
add detection logic circuit means for detecting concurrence of a first set of conditions comprising the occurrence of the add control signal and the occurrence of a signal at said output of said multiplexing means indicating that the one of said load control latch means then being addressed is in its load-off state;
shed logic detection means for detecting concurrence of a second set of conditions comprising the occurrence of the shed control signal and a signal at said output of said multiplexing means indicating that the one of said load control latch means then being addressed is in its load-on state; and
means connecting said add logic detection means and said shed logic detection means to said data input means of said plurality of load control latch means for responding to the detection by said add logic detection means of the concurrence of said first set of conditions to switch that one of said load control latch means then being addressed to said load-on state, and for responding to the detection by said shed logic detection means of the concurrence of said second set of conditions to switch that one of said load control latch means then being addressed to said load-off state.
2 Assignments
0 Petitions
Accused Products
Abstract
To maintain power consumption within predetermined limits, the ON/OFF states of a plurality of electrical loads are controlled by a digital load control circuit that forms part of a closed-loop control system. The power consumed by the ON loads is monitored and compared with a reference and in response to such comparison command signals are produced that instruct the digital circuit to add or shed loads as required, to increase or decrease, respectively, the power consumption. Inputs to the load-control circuit are in the form of one or more add or shed command pulses wherein the former instructs the circuit to add a load, and the latter instructs the circuit to shed a load. To execute these commands, the load-control circuit includes a reversible, recycling address generator that successively addresses a bank of addressable latches, one for controlling the ON/OFF state of each load. As the latches are successively addressed, logic circuitry operates to detect a concurrence of an add command and an OFF load state at the addressed latch, or a concurrence of a shed command and an ON load state at the addressed latch. Detection of the former set of conditions causes the then addressed latch to be switched from its load OFF state to its ON state and detection of the latter set of conditions causes the then addressed latch to be switched from its load ON state to its OFF state. Various embodiments of the foregoing are disclosed including circuitry for selectively dividing the plurality of loads into two different groups, one of which is a fixed priority group wherein the loads thereof are added and shed in a fixed order, and the other of which is a rotate group wherein the order that the loads are added and shed is rotated so that all of the loads of such group equally share the available ON time; and circuitry for selecting a limit to the total number of rotate loads that can be ON at any given time and a limit to the number of such loads that can be OFF at any given time.
-
Citations
19 Claims
-
1. A circuit for controlling the the "on/off" states of each of a plurality of electrical loads in response to power monitoring and signal generating circuit means that monitors the electrical power delivered to the "on" loads and produces an add control signal commanding the addition of one or more of the loads when power consumption is to be increased and produces a shed control signal commanding the shedding of one or more of said plurality of loads when such power consumption is to be decreased, comprising:
-
a plurality of individually addressable load control latch means, each having a load-off state and a load-on state, said plurality of load control latch means having a common data input means to which each of said load control latch means is individually responsive when it is addressed, each of said plurality of loads being adapted for control by a separate one of said load control latch means so that when each of said latch means is in its load-off state the load controlled thereby is "off", and when each of said latch means is in its load-on state, the load controlled thereby is "on"; address generating means for generating a succession of address signals, each such signal being effective to address a separate one of said plurality of load control latch means; multiplexing means responsive to said succession of address signals produced by said address generator means so as to be synchronously operated with the addressing of said load control latch means, said multiplexing means having a plurality of inputs each of which is connected to a separate one of said plurality of load control latch means, said multiplexing means having a common output at which a signal is produced indicating the state of that one of said load control latch means then being addressed by said counter means; add detection logic circuit means for detecting concurrence of a first set of conditions comprising the occurrence of the add control signal and the occurrence of a signal at said output of said multiplexing means indicating that the one of said load control latch means then being addressed is in its load-off state; shed logic detection means for detecting concurrence of a second set of conditions comprising the occurrence of the shed control signal and a signal at said output of said multiplexing means indicating that the one of said load control latch means then being addressed is in its load-on state; and means connecting said add logic detection means and said shed logic detection means to said data input means of said plurality of load control latch means for responding to the detection by said add logic detection means of the concurrence of said first set of conditions to switch that one of said load control latch means then being addressed to said load-on state, and for responding to the detection by said shed logic detection means of the concurrence of said second set of conditions to switch that one of said load control latch means then being addressed to said load-off state. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
-
-
16. A method of automatically controlling the "on/off" states of each of a plurality of electrical loads in response to the steps of monitoring the level of the electrical power delivered to the "on" loads, producing an add control signal for commanding the addition of one of the plurality of loads when power consumption is to be increased, and producing a shed control signal for commanding the shedding of one of the plurality of loads when power consumption is to be decreased, comprising the steps of:
-
controlling the "on/off" states of each of the plurality of electrical loads by a corresponding plurality of individually addressable electrical latches, one for each load, wherein each said latch, when addressed, is capable of being disposed in either a load-off state in which the load controlled thereby is switched "off", or a load-on state in which the load controlled thereby is switched "on"; repetitively generating a predetermined sequence of latch-addressing signals and applying said signals to said latches so as to individually address said latches in a given sequence; sensing the state of each of said latches at a time when each such latch is being addressed by a corresponding one of said latch-addressing signals; detecting the concurrence of said add control signal and the sensing of a load-off state of one of said latches and in response thereto switching such latch to its load-on state; and detecting the concurrence of said shed control signal and the sensing of a load-on state of one of said latches and in response thereto switching such latch to its load-off state. - View Dependent Claims (17, 18, 19)
-
Specification