Abstract:
Systems and devices for, and methods of, adaptive local energy storage capacity by changing operating set points of regulated energy load devices based on the presence, or absence, of an excess of available, generated energy.

Description:
TECHNICAL FIELD 
       [0001]    Embodiments pertain to systems and devices for, and methods of, adaptive local energy storage capacity. 
       BACKGROUND 
       [0002]    Energy consuming devices commonly consume energy to maintain some measurable condition within normal bounds. For example, a refrigerator will cycle its compressor to maintain an internal temperature between low and high temperature set points. Similarly regulated devices include air conditioners, freezers, air handling systems and water heaters. Residential solar panels and wind-based electrical power generating systems may dump generated energy when they exceed the capacity of their respective target electrical system to absorb the load. This dumping can occur when the target electricity grid is disconnected due to an outage, when the home operates off-grid, or when the capacity of an electrical component in the electric generation path is exceeded. 
       SUMMARY 
       [0003]    Exemplary embodiments include systems, devices, and methods. For example, a device embodiment for energy management may comprise: a central processing unit (CPU) and memory where the CPU is configured to: (a) engage an energy load device of highest priority not already engaged via a control signal, wherein the control signal invokes at least one of: a set point override and a set point modification, if the energy supply level is greater than the measured energy consumption level; and (b) disengage an energy load device of lowest priority not already disengaged via a release signal, wherein the release signal invokes at least one of: a relinquishment of an override and a restoration of an original set point, if the energy supply level is less than the measured energy consumption level. The control signal of the exemplary device may comprise a command to override a set point of a regulated energy load device; and the release signal may comprise a command to restore a set point of a regulated energy load device having an overridden set point. The control signal of the exemplary device may comprise a command to shift one or more set points, of a regulated energy load device, from nominal values to preset values stored at the regulated energy load device; and the release signal may comprise a command to restore one or more shifted set points of a regulated energy load device to the nominal values. In some embodiments, the control signal of the exemplary device may comprise one or more set point updates and a command to replace nominal values of one or more set points of a regulated energy load device with an update value; and the release signal may comprise a command to restore one or more updated set point values of a regulated energy load device to the nominal values. In other embodiments, the control signal of the exemplary device may comprise one or more set point updates and a command to replace one or more set points of a regulated energy load device with an update value; and the release signal may comprise nominal values and a command to replace the one or more updated set point values of a regulated energy load device with the received nominal value. In other embodiments, the exemplary device may be configured to provide excess power to an external grid and provision this excess power to the external grid based on a capacity of the external grid to receive this excess power. 
         [0004]    A method embodiment for energy management in a system of one or more energy load devices may comprise the steps of: (a) if the system comprises two or more energy load devices, then establishing an energy load device priority among the two or more energy load devices; (b) determining an energy supply level to the system; (c) determining a total energy consumption level based on the one or more energy load devices; (d) if the energy supply level is greater than the measured energy consumption level, then engaging a load device of highest priority not already engaged via a control signal, wherein the control signal invokes at least one of: a set point override and a set point modification; and (e) if the energy supply level is less than the measured energy consumption level, then disengaging a load device of lowest priority not already disengaged via a release signal, wherein the release signal invokes at least one of: a relinquishment of an override and a restoration of an original set point. The step of engaging may be via a control signal comprising a command to override a set point of a regulated energy load device; and the step of disengaging may be via a release signal comprising a command to restore a set point of a regulated energy load device having an overridden set point. The step of engaging may be via a control signal comprising a command to shift one or more set points, of a regulated energy load device, from nominal values to preset values stored at the regulated energy load device; and the step of disengaging may be via a release signal comprising a command to restore one or more shifted set points of a regulated energy load device to the nominal values. In some embodiments, the step of engaging may be via a control signal comprising one or more set point updates and a command to replace nominal values of one or more set points of a regulated energy load device with an update value; and the step of disengaging may be via a release signal comprising a command to restore one or more updated set point values of a regulated energy load device to the nominal values. In other embodiments, the step of engaging may be via a control signal comprising one or more set point updates and a command to replace one or more set points of a regulated energy load device with an update value; and the step of disengaging may be via a release signal comprising nominal values and a command to replace the one or more updated set point values of a regulated energy load device with the received nominal value. In other embodiments, the method of energy management further comprising the steps of: (a) determining whether the system has excess power; and (b) determining the capacity of an external grid to receive excess power generated by the system. In other embodiments, the method of energy management wherein power is delivered to an external grid having a determined capacity to receive excess power. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0005]    Embodiments are illustrated by way of example and not limitation in the figures of the accompanying drawings, and in which: 
           [0006]      FIG. 1  is a functional block diagram of an exemplary system embodiment; 
           [0007]      FIG. 2  is a functional block diagram of an exemplary system controller; 
           [0008]      FIG. 3  is a flowchart depicting an exemplary process of the system controller; 
           [0009]      FIG. 4  is a functional block diagram of another exemplary system embodiment; 
           [0010]      FIG. 5  is a flowchart depicting an exemplary process of a subsystem controller of a local device; and 
           [0011]      FIG. 6  is a functional block diagram of another exemplary system embodiment. 
       
    
    
     DETAILED DESCRIPTION 
       [0012]    An energy management system monitors the output of energy generation devices in the system and energy consuming devices in the system. When the energy management system detects that energy generation exceeds the ability of the system to absorb that energy, the energy management system checks energy load devices in the system, e.g., appliances in the home, that may be engaged beyond their respective regulated cycling, to absorb the excess energy. The energy load devices may be evaluated and prioritized based on: the efficiency at which they can use this energy, the amount of energy they can absorb, and by user preference. 
         [0013]    The energy management system may then engage the loads to match the energy supply, and may do so based on the prioritized ranking of energy load devices in the system that are, as of yet, not engaged. Normal operating limits of the energy load devices may be set for maximum energy efficiency and the maximum operating limits of the load devices may be set for safety and user tolerance. So, when the difference between electricity generation and consumption returns to within a nominal range, such that this exceptional state is not required, the appliances that have absorbed this excess energy may then draw on this energy, via the delay of their respective next on-cycle, that may be extended with the re-application of their normal, or nominal, set points. 
         [0014]    Examples of local regulated energy load devices include: a water heater that has preheated the hot water supply; an air conditioner that has pre-cooled the living space; a battery storage system that has charged into a less efficient state of charge; a food refrigeration system that has pre-cooled food, but not cooled below freezing; and a food freezer that has super cooled the food therein. 
         [0015]      FIG. 1  is a functional block diagram of an exemplary system  100  embodiment where a power source  110  provides power to a first local device  130  and a second local device  131 . The power source  110  may comprise a local power source  111  and/or the general electrical utility grid  112 . A system controller  120  may direct power from either source  111 ,  113 , for example, via power switches, S 1  and S 2 . The system controller  120  is configured to monitor local power generation level of the local power source  111 , and the power consumption levels of the local devices  130 , 131 . Based on the generation and consumption levels, the system controller  120  may effect a closing of the first power switch, S 1 , or a closing of the second power switch, S 2 . If the local power source  111  is generating more power than can be consumed and stored by the local devices  130 ,  131 , then the system controller  120  may effect a closing of a third power switch, S 3 , and thereby direct at least a portion of the power being generated by the local power source  111  to the grid  112 . Alternative embodiments to the exemplary power switches S 1 , S 2 , and S 3 , may include power control circuitry to manage by direction the flow of energy. The first local device  130  is depicted as comprising a subsystem controller  140  and a power-consuming element  150 . The power-consuming element  150  is depicted as effecting a change in the energy state of a target mass  132 . The energy state of the target mass  132  is depicted as monitored by the subsystem controller  140 . The second local device  131  is depicted as comprising a subsystem controller  160  and battery charging circuitry  170 . The battery charging circuitry  170  is depicted as effecting a change in the energy state of a battery  133 . The energy state of the battery  133  is depicted as monitored by the subsystem controller  160  of the second local device  131 . 
         [0016]      FIG. 2  is a functional block diagram of an exemplary system controller  220  having a processor  224  and memory  227  addressable via a data bus  228 . A user interface  229 , a power source interface  221 , and an interface  226  by which one or more local devices may communicate with the processor  224  via the data bus  228 . The processor  224  may be configured to execute programmed steps via a real-time operating system  225  where the steps that comprise the application  222  include energy consumption and/or energy production inputs that are taken or estimated, comparisons are made with load capabilities and priorities of engaging or disengaging load elements, and commands and/or values are sent to local devices for energy management. 
         [0017]    For example,  FIG. 3  is a flowchart depicting an exemplary process of the system controller  300 . The system controller may be provided or be pre-loaded with a set of one or more energy load priorities. Accordingly, the system controller may input one or more energy load priorities (step  310 ) associated with the local devices of the system. The system controller is depicted in  FIG. 3  as inputting (step  320 ) an energy supply level (ESL), i.e., the present level of generated energy available to the local devices under the control of the system controller. The system controller is also depicted as optionally inputting (step  330 ) or estimating the separate or combined energy level of dissipation (EDL), i.e., the combined energy consumption level, by the one or more active energy loads. An error margin, ε, may be referenced to provide a hysteresis effect to the following exemplary switching logic. The system controller may test (test  340 ) whether the ESL, less the marginal value of ε, is greater than the EDL. If so, then the system controller may output a command to effect an engagement of an energy load, not already engaged, that is the load of highest priority—i.e., according to the set of energy load priorities (step  350 ). If not, the system controller may test (test  360 ) whether the ESL, less the marginal value of ε, is less than or equal to the EDL. If so, then the system controller may output a command to effect a disengagement of a load (step  370 ), not already disengaged, that is the energy load of lowest priority—according to the set of energy load priorities. 
         [0018]      FIG. 4  is a functional block diagram of an exemplary system embodiment  400  comprising a power source  410 , a system controller  420 , a local device  430 , a target mass  432 , and a temperature sensor  490 . The local energy load device  430  is depicted as comprising a subsystem controller  440  and a refrigeration unit  450 . The system controller is depicted as inputting the energy supply level (ESL)  411  of the power source  410  and the energy dissipation level (EDL)  412  as being drawn from the power source  410  by the local device  430 . The refrigeration unit  450  effects a change in the energy state of the target mass  432  and the temperature of the target mass  432  is depicted as being measured by a temperature sensor  490 . The output of the temperature sensor may be provided to the subsystem control  440 , the system controller  420 , or both. The system controller  420  may generate a command to override the local logic of the subsystem controller  440  to effect an engagement or a disengagement of the refrigeration unit  450 . The subsystem controller  440  may have controller logic  441 , and the system controller  420  may generate a command to shift temperature settings  442  within the controller logic  441 . For example, if the system controller  420  determines that, based on the difference between the energy supply level (ESL)  411  and the energy dissipation level (EDL)  412 , the target mass  432  should be over-chilled to take advantage of the excess in generated energy, then the system controller  420  may send new temperature settings  442 , e.g., T′ off  and T′ on . Optionally, the system controller  420  may send a signal to shift the temperature settings  442  to a stored set of temperature settings  442 , e.g., T off  to T′ off  and T on  to T′ on . Also, if the system controller  420  determines that, based on the difference between the energy supply level (ESL)  411  and the energy dissipation level (EDL)  412 , the target mass should be returned to default settings, then the system controller  420  may send a reset signal to reset the temperature settings  442 , e.g., T′ off  to T off  and T′ on  to T on . 
         [0019]    For example,  FIG. 5  is a flowchart depicting an exemplary process of a subsystem controller of a local device. The subsystem controller may determine (test  510 ) whether it has received an engagement override signal, and if so, the subsystem controller engages or disengages a load (step  520 ) based on information contained in the engagement signal. The subsystem controller may determine (test  530 ) whether it has received a set point shift command, and if so, the subsystem controller shifts one or more set points (step  540 ) based on the information contained in the set point shift command signal. The subsystem controller may determine (test  550 ) whether it has received an update signal for one or more set points, and if so, the subsystem controller replaces one or more received set point updates (step  560 ) based on the information contained in the set point update signal. 
         [0020]      FIG. 6  is a functional block diagram of an exemplary system embodiment  600  comprising a power source  610 , a system controller  620 , a local energy load device  630 , and a chemical battery  643  or chemical battery array. In place of, or in addition to, the chemical battery, other energy storage devices may be employed, such as kinetic (e.g., flywheel) systems and/or pneumatic (e.g., pressure exchange) systems. The local energy load device  630  is depicted as comprising a subsystem controller  660  and a charging circuit  670 . The system controller is depicted as inputting the energy supply level (ESL)  611  of the power source  610  and the energy dissipation level (EDL)  612  as power is being drawn from the power source  610  by the local device  630 . Optionally, the EDL  612  may be estimated or a nominal value for each energy load device may be referenced for combination as the EDL  612 . The charging circuit  670  effects a change in the energy state of the chemical battery  643 , and the temperature of the chemical battery  643  is depicted as being measured by a temperature sensor  675 . The output of the temperature sensor  675  may be provided to the subsystem controller  660 , the system controller  620 , or both. The system controller  620  may generate a command to override the local logic of the subsystem controller  660  to effect an engagement or a disengagement of the charging circuit  670 . The subsystem controller  660  may include: a regulator set point  661  that may be preset or overwritten by the system controller  620 ; and a first current reference value  663 , I ref , a second current reference value  664 , I′ ref , and a logical switch  662  that may be set via a command signal from the system controller  620 . The subsystem controller  660  may also include a first voltage reference value  665 , V ref , a second voltage reference value  667 , V′ ref , and a second logical switch  666  that may be set via a command signal from the system controller  620 . For example, if the system controller  620  determines that, based on the difference between the energy supply level (ESL)  611  and the energy dissipation level (EDL)  612 , the battery should be charged to take advantage of the excess in available energy, then the system controller  620  may send a new regulator set point value and/or signals to effect the switching to the second current reference value  664 , I′ ref , and/or to effect the switching to the second voltage reference value  667 , V′ ref . Optionally, the system controller  620  may send replacement values for the current reference, I ref , and/or the voltage reference V ref . Also optionally, the system controller  620  may send a signal to shift the regulator set point  661  to a preset value. The charging circuit  670  is depicted as comprising a regulator  671 , a current controller  672  based on a reference current value, a voltage controller  674  bases on a reference voltage value, and the charging circuit  670  that may include the temperature sensor  675 . 
         [0021]    It is contemplated that various combinations and/or sub-combinations of the specific features and aspects of the above embodiments may be made and still fall within the scope of the invention. Accordingly, it should be understood that various features and aspects of the disclosed embodiments may be combined with or substituted for one another in order to form varying modes of the disclosed invention. Further it is intended that the scope of the present invention herein disclosed by way of examples should not be limited by the particular disclosed embodiments described above.