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).

Abstract: The present invention contemplates a method and apparatus for load-shedding duty cycling which overrides the normal thermostat control in a space conditioning system, upon receipt of an external signal as from the power company, in a manner such that the consumed power does not rise above the level that persisted just prior to the initialization signal. The present invention monitors the thermostat-controlled cycling pattern of a space conditioning system such as an air conditioner. Normally, the last thermostat-controlled cycle is then caused to become the reference or control cycle for the load shedding interval. That is, the ON portion of the reference cycle is caused to become the maximum allowable ON interval and the OFF portion of the reference cycle is caused to become the minimum OFF interval for the entire load shedding interval.The device may be started by a single radio command or other means. The release from load control may be automatically timed or based on other signals.

Abstract: An energy management system which automatically limits the total instantaneous consumption of electrical energy in a residence having a plurality of energy consuming loads having different current demands, while maintaining the consumption of electrical energy as high as possible without exceeding a predetermined peak total current demand. Sensor means measure the total current to all of the loads which are then in operation and generates a signal indicating the total current. Current interrupters, controlled by the logic of a microprocessor automatically interrupt the current, if any, to each of the loads in a predetermined sequence, when the total current to the loads then in operation exceeds the predetermined peak total demand. Enough of the loads are shed until the total current is less than the predetermined peak total.

Abstract: A system for controlling electrical load shedding and restoring operations includes a microprocessor system, a power measuring circuit, and a plurality of load switching relays controlled by the microprocessor system to electrically connect controlled loads of a residence to, and electrically disconnect the controlled loads from, a power line in accordance with priorities associated with the controlled loads.

Abstract: An energy management system for a group of electrical loads such as in an industrial plant. The electrical power usage by the group of loads is elastically maintained between an upper set point and a lower low limit point, which is a percentage of the set point, at all times. The electrical load demand is presented in the form of a demand count to a comparator whose output provides a load display and couples load information to a sequencer. The sequencer cycles those loads which are off through the group of controlled loads and also varies the number of off loads in response to the comparator information. The set point floats and is responsive to actual power demand and a memory may be utilized to affect the sequencer operation dependent upon preprogrammed instructions for particular loads on particular days.

Abstract: System, method and apparatus for carrying out the shedding of electrical loads on a predetermined priority basis. A sensor network (32) detects a demand load at a power input (10) and develops a signal representative thereof. This signal is introduced to a series of controllers (36-39) along with a signal from an allowable load control circuit (48) which represents a predetermined maximum allowable load value. The controllers respond when the demand load is higher than the allowable load, a priority delay network (108) in each having a time-out interval corresponding with the relative priority basis assigned each load. Simultaneously, with the shedding of a load at the termination of the priority delay, a fictitious load feedback signal (102) is summed (96) with the demand load signal of the sensor. A reset control (90) responds in conjunction with a predetermined review interval timing function (144) to re-evaluate the priorities of shed loads in the event of a drop in demand load.

Abstract: Method and apparatus for minimizing the peak load usage in electrical systems having multiple electrical power loads when each load is provided electrical power from an electrical source and including first switch means disposed in the power supply to each individual load, operator means to selectively open and close the first switch means, control means to selectively control the operator means, real time clock means to supply real time to the control means where the control means is adapted to actuate and deactuate each operator means at a preselected time to correspondingly open and close the first switch means associated with the operator means where the control means prevents simultaneous actuation of more than one operator means within a selected time interval, power outage detector means in cooperative association with the power source means to detect a power interruption at the power source means, second control means actuated upon resumption of power after interruption including input means, where th

Abstract: A load demand control system for limiting the total average electric load over a moving predetermined time interval to an installation having at least one large load device, making use of a timer control which can be selectively operated by an operator upon the need for the operation of the one large electrical load. The timer control first resets the control point of the load demand control of the installation at some low predetermined value. Subsequently, the timer control turns on the large load for a predetermined period of time and after its operation, the timer control maintains the low predetermined value of the load demand control for a further predetermined time period whereby the total moving average electrical load to the installation for the total time interval of the timer control is maintained below a predetermined peak electrical load value set for the installation.

Abstract: A system for allocating energy adapted to be coupled to a plurality of conditioning equipment systems utilized to alter a plurality of corresponding first conditions. Thermal sensors for monitoring the conditions in each of a plurality of environments are coupled to allocation circuitry which provides for activation of control channels of the allocation circuitry in an order determined by the relative demand for conditioning of the plurality of environments. When two or more environments are determined to have the same demand for conditioning, the control channels of the allocation circuitry are activated in a controlled order. When a predetermined number of control channels have been activated, the process of allocation is terminated by the allocation circuitry. When more than the predetermined number of control channels is activated in case of a failure of the system, an alarm is activated and all previously activated control channels are deactivated.

Abstract: A power supply system for a number of functional units distributed along a transmission in which each unit gets its supply from a constant voltage circuit connected across the transmission line. Each unit may have a low power and a high power state. The power supply which is located at one end of the transmission line is a constant voltage supply with current limiting features. The constant voltage circuits each comprises a Zener diode connected in series with an adjustable constant current circuit and a system for setting the constant current circuit on either the low or the high power state. When the high power state is set, the voltage across the constant current circuit is sensed and if this voltage is too high, the constant current is further increased until the current limiting of the power supply operates thereby decreasing the voltage across the constant current circuit to a safe value.

Abstract: An energy management method for controlling electrical power consumption in each of a plurality of residential circuits having a plurality of loads. Each residential circuit is provided with a variable limit demand controller which includes means for receiving utility-generated demand limit signals from a remote location. A demand limit is established for each of the residential circuits which is independent of which of the specific loads in the circuit are responsible for the demand. Signals are generated by the utility from a remote location to vary the limit proportionately in all of the residential circuits.In a preferred embodiment, in which the loads in each of the circuits include both resistive and reactive loads, each circuit is provided with separate variable limit demand controllers for the resistive loads and for the reactive loads.

Abstract: A system is disclosed for monitoring and controlling the consumption of electrical energy and the peak demand for electrical power in an installation. The system can be programmed to automatically limit the instantaneous power consumption of the installation in accordance with the time of day and the required need of the facility. The system sheds appropriate individual loads when the total instantaneous power consumption exceeds the pre-selected set point applicable for the time in question, to thereby return the power consumption of the installation to within this allowable limit. Provision is made for selective load shedding whereby the relative size of the load shed corresponds with the relative degree of power overdraw. In addition, after each shedding event, the system automatically realigns the order of priority by which the loads are shed. Furthrmore, all shed loads are automatically reset to an operative condition on a periodic basic, according to the operating requirements of each load.

Abstract: An energy management method employing apparatus for automatically limiting the total instant consumption of electrical energy in a residential circuit having a plurality of energy-consuming variable demand loads having different nominal current demands. A predetermined load shedding sequence is established which is independent of the nominal current demands of the load. The actual current consumption value of each load shed is measured. Shed loads are restored which, according to their actual values and independent of their nominal values, can be restored without causing the total current in residential circuit to exceed the preselected demand. Measurement of the consumption values of the shed loads enables load restoration selections based thereon without modification of the energy management apparatus to account for variations in the nominal demands of the loads.

Abstract: A method and system for controlling peak electrical demand placed on a source of electrical energy by a plurality of electrical loads that include at least one electrical load of lower priority than at least another of the loads. Demand for electrical energy by the loads connected to the source of electrical energy is sensed and, in response to the sensed demand exceeding a predetermined value the loads are selectively disconnected from the source. Normally, all the loads are connected to the source in the absence of a sensed excessive demand condition. Therefore, all demand control is lost in the event of failure of the controller. Accordingly, the system senses an abnormal operating condition of the controlling system of the type that renders the selective disconnecting means inoperative to disconnect the loads from the source. The electrical load of lower priority is then disconnected from the source for the duration of the sensed abnormal condition.

Abstract: In a power utilization system having loads drawing energy from a utility company, some loads are adjustable and, as part of computerized power demand control system, loads are regulated as well as switched ON or OFF in order to meet an assigned power demand limit. The adjustable loads draw power in accordance with a local supply controller, such as a tap changer, but regulated amounts of power are established by the computer with a set point which is a function of the demand error calculated in an outer loop by the power demand control system and maintained by the computer in a closed loop from an individual power meter and with the established set point. The priority schedule and error computations take into account the amounts of power drawn by adjustable loads as well as the amounts drawn by loads which can be shed, or reconnected.

Abstract: Power demand control on a plant having a plurality of load units of production, each operating between a starting time and an ending time to provide individual production outputs, is exercised by automatically shedding or restoring such load units in order to maintain power demand within an assigned demand limit. The control system provides adaptive priority determination by storing an image of the ON, or OFF, status of the load units into at least two memories (memory I and memory II) on a last ON, first OFF basis for the loads to be shed, and on a last OFF, first ON basis for the loads to be restored. Loads that are ON are stored in a first (ON) memory (memory I); loads that are being held OFF by the controller are stored in a second (DCOFF) memory (memory III). Also provided is a third memory (OFF) (memory II) to store the status of load units which are out of production and under independent control either after ending production or while being made ready to start production.

Abstract: An energy management system for limiting continuously instantaneous permissible power level of a plurality of controllable loads including a transducer device for generating an output signal when the measured instantaneous power level exceeds a pre-set instantaneous permissible power level. A programmable matrix device is provided to select a plurality of controllable loads and periods of time in a day for which each of the selected loads are connected to a power source. The selected controllable loads are disconnected from the power source in response to the output signal in a predetermined order. The order in which the selected loads are to be disconnected is sequentially switched over a certain time interval.

Abstract: In an electrical load control system, an analog signal representing the actual rate of power being consumed by a plurality of loads has a nominal level when the actual rate is at a desired rate, or set point. As the level of the analog signal deviates from its nominal level, the electrical load control system functions to add or shed one or more of the loads to maintain the actual rate at the set point. During times of low power consumption, the electrical load control system may not act to optimize energy usage if the set point is not lowered. A set point control circuit is provided which senses the on/off status of one of the loads, or control load, and which provides a set point modification signal whose level represents a desired reduction in the set point and which varies in a predetermined range between minimum and maximum levels representing, respectively, no reduction in the set point and a maximum reduction in the set point.

Abstract: In a system for limiting power consumption during peak power consuming periods, a proportional demand limit controller is disclosed having a condition sensor for sensing the condition of air being supplied to a space, a reset circuit responsive to the condition sensor for controlling a load connected thereto for in turn controlling the condition of the air being supplied to the space, and a proportional demand controller for sensing load consumption of the loads within a building and for resetting the reset circuit in a manner to maintain the power consumption of the building loads below a predetermined demand limit.

Abstract: A power demand limiting circuit is disclosed comprising air temperature control apparatus coupled with a municipal source of electric current through a thermo-responsive switch, through a meter having means for measuring maximum power demand for any period in a succession of periods of preselected duration, and through a timer programmed to cycle a timer switch at least once during each of the periods, whereby the air temperature control apparatus is rendered incapable of demanding power continuously throughout any of the metered periods.

Abstract: A demand controller includes a microprocessor which is programmed to input data from switches on a control panel and output data to a set of eight circuits which control the operation of loads. Peak power demand is maintained below a preset DEMAND OBJECTIVE by selectively shedding these loads. The shed level for each load is not fixed, but instead, varies as a function of the rate at which total power demand is increasing. This rate is calculated by the microprocessor and the resulting shed level index (i) is employed to select the proper shed level for each load from a stored shed level matrix.

Abstract: 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.

Abstract: A power supply provides a low-level DC voltage to DC load circuits by first rectifying the standard AC voltage and thereafter reducing the rectified AC voltage to the low-level DC voltage. The reduction of the rectified AC voltage to the low-level DC voltage is accomplished by a power transformer which is switched on or off by a pair of switching transistors. The switching transistors are operated in a "push-pull" mode by a pair of control transformers operating in combination with a control circuit. The control circuit produces various pulse conditions in the control transformers which turn their respective switching transistors on and off in a prescribed manner. An overcurrent sensing and control device prevents damage to components.

Abstract: A stabilized power supply circuit has a stabilized or regulator circuit connected between an input terminal and a first output terminal and a constant voltage element for example, a Zener diode, whose one electrode is connected to the input terminal and whose other electrode is connected to the first output terminal, and a second output terminal is connected to the first-mentioned electrode of the constant voltage element.

Abstract: A peak load control and power-distributing system for residential or small commercial/industrial use in which some loads are uncontrolled and others are controlled. Current transformers in the main feeder for all loads supply current to a thermal switch to detect when the power demand exceeds a predetermined value. The thermal switch starts a small synchronous motor having gears driving a shaft with cams operating microswitches for the controlled loads. One cam switch enables the motor to operate through a preprogrammed cycle, and to turn off at the end of a cycle whenever the thermal switch indicates the power demand has dropped below the predetermined value.