CN106688155B - System and method for switching electrical system to standby power in a utility power outage - Google Patents

Abstract

Apparatus (215) for managing an electrical system (200), comprising: a main circuit breaker (220) configured to be coupled to a mains power supply (205); an LER breaker (240) structured to be coupled to a local power generation source (245); a number of branch circuit breakers (230), each branch circuit breaker configured to be coupled to one or more loads (235); and a control component (250). The control component is configured to, in response to a determination that the mains power supply is experiencing a power outage: causing the main circuit breaker to be opened; determining which one or more of the number of branch breakers are to receive backup power from the local power generation source; configuring the branch circuit breakers such that only one or more of the determined number of branch circuit breakers are in a closed condition; and causing the local power generation source to be activated.

Description

System and method for switching electrical system to standby power in a utility power outage

Cross reference to related applications

This application claims priority to U.S. provisional patent application serial No. 62/045,864, filed on 9/4/2014, the disclosure of which is incorporated herein by reference.

Technical Field

The disclosed concept relates generally to power distribution systems and, more particularly, to systems and methods for switching electrical systems (such as residential electrical systems) to local power generation sources during a main utility power outage without the use of automatic transfer switches or similar devices.

Background

Distributed power, sometimes referred to as a local power generation source or local energy source, is a small-scale power generation facility used to provide an alternative or enhancement to traditional power systems. Distributed power sources include, for example and without limitation, Photovoltaic (PV) modules (coupled to a DC/AC inverter), wind turbine modules (coupled to a DC/AC inverter), natural gas turbines, backup generators, energy storage devices, and uninterruptible power supplies.

When PV modules, generators, and/or other local power generation sources like those just described are installed in a location (such as a residence), they are not allowed to generate power during a utility outage unless they are isolated from the utility grid. This limitation is appropriate in order to prevent power from being fed back onto the grid by local power generation sources during a power outage-a situation that can present a hazard to workers working on the grid.

Typically, this problem is addressed by using a system 100 as shown in fig. 1, the system 100 using an Automatic Transfer Switch (ATS) to ensure a safe transition to a local power generation source during a power outage. As is known in the art, an ATS is an electrical switch that switches a load between two sources. As seen in fig. 1, system 100 includes a mains power supply 105, a primary meter 110, and a load center 115 coupled to primary meter 110 for receiving power from mains power supply 105. The load center 115 includes a number of conventional circuit breakers, including a conventional main circuit breaker 120, a number of conventional branch circuit breakers 125, and a conventional local energy source (LER) circuit breaker 130 (which is simply a conventional circuit breaker coupled to a local power generation source as described below). As can be seen in fig. 1, conventional branch circuit breakers 125A and 125B are coupled to and provide protection for a number of "non-critical" loads 130 (i.e., loads that have been previously determined to not be configured to receive backup power in the event of a utility power outage). The remaining conventional branch circuit breakers (labeled 125C) are coupled to the ATS 135 (or alternatively another switching device, such as a manual transfer switch). The output of the ATS 135 is provided to a secondary panel (sub) 140, which sub panel 140 in turn feeds a number of predetermined "critical" loads 145 (i.e., loads that have been previously determined to be configured to receive backup power in the event of a utility power outage). Further, the system 100 includes a local power generation source 150, which may be, for example and without limitation, a PV module coupled to an inverter or any other suitable distributed power source. The output of the local power generation source 150 is supplied to the ATS 135 and to a grid tie disconnect (grid tie disconnect) 155. Thus, the ATS has two inputs (i.e., an output received from the conventional branch breaker 125C and an output received from the local power generation source 150) and a single output selectable between 2 inputs.

In operation, under normal operating conditions, wherein the mains power supply 105 is not experiencing a power outage, the automatic transfer switch 135 is configured in a manner wherein an input received from the conventional branch breaker 125 is coupled to an output provided to the secondary distribution board 140. Further, under this normal condition, the grid disconnect device 155 is closed so that the local power generation source 150 can feed back electric power to the utility power supply 105. When the utility power source 105 experiences a power outage, the grid disconnect 155 is opened to isolate the local power generation source 150 from the load center 115 and the utility power source 105, thus protecting any workers that may be working on the utility power grid. Once grid disconnect 155 is opened, automatic transfer switch 135 may be switched to a configuration in which an input received from local power generation source 150 is coupled to an output provided to secondary distribution board 140. As a result, in this power-off condition, the predetermined critical loads 145 are able to receive power from the local power generation source 150.

While the system 100 described above is effective, it can add additional floor cost and complexity to the residential electrical system. Moreover, the system 100 is limited in that it must be sized and configured in advance based on predetermined load profiles (i.e., load profiles of certain predetermined loads to be powered by the local power generation sources 150 during a power outage). It will be appreciated that this eliminates any flexibility in determining which loads will be powered by the local power generation source 150.

Disclosure of Invention

In one embodiment, an apparatus for managing an electrical system is provided. The apparatus comprises: a main circuit breaker configured to be coupled to a mains power supply; an LER breaker configured to couple to a local power generation source; a number of branch circuit breakers, each branch circuit breaker configured to be coupled to one or more loads; and a control assembly. The control component is configured to, in response to a determination that the mains power supply is experiencing a power outage: causing the main circuit breaker to be opened; determining which one or more of the number of branch breakers are to receive backup power from the local power generation source; configuring the branch circuit breakers such that only one or more of the determined number of branch circuit breakers are in a closed condition; and causing the local power generation source to be activated.

In another embodiment, a method is provided for controlling an electrical system that includes a main circuit breaker provided at a load center and coupled to a mains power source, an LER circuit breaker provided at the load center and coupled to a local generation source, and a number of branch circuit breakers provided at the load center and each coupled to one or more loads. The method comprises the following steps: determining that the mains power supply is experiencing a power outage in the load center; in response to determining that the mains power supply is experiencing a power outage, causing the main circuit breaker to be opened by providing first communication information to the main circuit breaker; determining which one or more of the number of branch breakers are to receive backup power from the local power generation source; configuring the branch circuit breakers such that only the determined one or more branch circuit breakers of the number of branch circuit breakers are in a closed condition by providing second communication information to the branch circuit breakers that do not include the one or more of the number of branch circuit breakers; and causing the local power generation source to be activated by providing third communication information to the local power generation source.

Drawings

A full appreciation of the disclosed concepts can be gained from the following description of the preferred embodiments when read in connection with the accompanying drawings, in which:

FIG. 1 is a schematic diagram of a prior art system that uses an automatic transfer switch to ensure a safe transition to a local power generation source during a power outage;

FIG. 2 is a schematic diagram of a system for ensuring a safe transition to a local power generation source during a power outage in accordance with an exemplary embodiment of the present invention;

FIG. 3 is a flowchart illustrating a control method of the system of FIG. 2, according to an exemplary embodiment of the present invention;

fig. 4-7 are diagrams of exemplary circuit breakers that may be used to implement the system of fig. 2 and the method of fig. 3.

Detailed Description

Directional phrases used herein, such as, for example, left, right, front, back, top, bottom and derivatives thereof, relate to the orientation of the elements shown in the drawings and are not limiting upon the claims unless expressly recited therein.

The term "number" as used herein means 1 or an integer greater than 1 (i.e., a plurality).

The statement that two or more parts are "coupled" together as used herein means that the parts are connected together either directly or through one or more intermediate part connections.

The term "component" as used herein is intended to refer to a computer-related entity, either hardware, a combination of hardware and software, or software in execution. For example, a component can be, but is not limited to being, a process running on a processor, an object, a thread of executable execution, a program, and/or a computer. By way of illustration, an application running on a processor or server and the processor or server can be a component. One or more components may reside within a process and/or thread of execution and a component may be localized on one computer/processor and/or distributed between two or more computers/processors.

Fig. 2 is a power distribution system 200 in accordance with one non-limiting exemplary embodiment of the disclosed concept. As described in greater detail herein, the system 200 includes a system of controllable (and in an exemplary embodiment quantifiable) circuit breakers, including a main circuit breaker and a subset of branch circuit breakers downstream of the main circuit breaker. System 200 implements a control method (illustrated in fig. 3 and described in detail with respect to fig. 3) that enables a local power generation source, such as, but not limited to, a PV module coupled to an inverter, to be safely placed into service in a power outage condition without the use of an ATS, such as ATS 135 shown in fig. 1, or similar switching device. As described in greater detail herein, in an exemplary embodiment, a control method determines when there is a utility power outage, isolates a load switchboard coupled to the utility grid, brings a local power generation source safely online for a desired time, coordinates load demand with local power generation supply capacity, and safely restores grid power when the outage condition subsides. With respect to coordination of load demand with local generation supply capacity, the method uses a control element in which the load demand is managed (i.e., the load is coupled to the local generation supply by closing an associated circuit breaker) to ensure that the load demand does not exceed the actual local generation supply capacity. The method may optionally use synchronization between multiple local power generation sources (if provided) and/or phase synchronization with grid power to allow seamless or "blinkless" transfer of power. As described in detail herein, this control method is achieved by directly controlling the circuit breakers in the system 200 rather than using a conventional switching mechanism (such as an ATS). A load panel coupled to a utility grid may be isolated from the grid by tripping a main breaker, and load demand may be balanced to match local power generation supply capacity by switching several branch breakers on and off. In other words, the power demand of the load may be controlled so as to prevent it from exceeding the power supply capacity of the local power generation source. In practice, the system 200 is able to dynamically determine the amount of local generation supply available from a local generation source (local generation source 245 described herein) and then coordinate with other circuit breakers in the system 200 (branch circuit breakers 230 described herein) to close only those circuit breakers that can be supported by the local generation source without overloading.

In a non-limiting exemplary embodiment of the disclosed concept, each controllable circuit breaker used in the system 200 as described herein is in the form of a Power Vending Machine (PVM) circuit breaker 400, the Power Vending Machine (PVM) circuit breaker 400 being described in detail in U.S. patent application publication nos. 2014/0211345 and 2014/0214218 owned by the assignee of the present invention, the disclosures of which are incorporated herein by reference in their entirety. However, it is to be understood that the use of the PVM circuit breaker 400 in the system 200 is for illustrative purposes only, and is not limiting, and that alternative types of controllable circuit breakers may be used. For example, and not by way of limitation, the one or more controllable circuit breakers used in System 200 may be smart circuit breakers as described in U.S. patent application serial No. 14/264,409 entitled "Microgrid System Structured to detected Overload conditioners and Take Corrective Actions repositioning Thereto," which is owned by the assignee of the present application and incorporated herein by reference, or remotely controllable circuit breakers having a second pair of separable contacts in series with primary separable contacts as described in, for example, U.S. patent nos. 5,301,083, 5,373,411, 6,477,022, and 6,507,255.

An exemplary PVM circuit breaker 400 is schematically illustrated in fig. 4, including four types of functions: (1) circuit protection functions, including traditional thermo-magnetic circuit protection, short circuit protection, overload protection, ground fault protection, arc fault protection, and/or other types of protection as needed, (2) branch circuit metering functions, including utility grade net metering (± 0.2%) and time-stamped values, (3) remote control functions for operating controllable contacts, including on/off control relay functions, independent of circuit breaker trip mechanisms, (4) wired and/or wireless communication functions, including functions for sending and receiving meter control and status information, backup functions for communicating during power outage conditions, and optional load-specific control features/signals configured to control special types of connected loads (such as Electric Vehicle Supply Equipment (EVSE) versions of circuit breakers capable of directly charging Electric Vehicles (EVs), HVAC circuit breakers capable of directly and independently controlling fans, compressors, and heating units, and lighting control circuit breakers including dimming capability, which substantially eliminate the need to control thermostats, either directly through the opening and closing of the circuit or through low voltage signaling; LER circuit breaker 240 as described herein is another example where load specific control features may be used to turn connected local power generation sources on and off as needed). In an exemplary embodiment, functions (2) - (4) under the control of microcontroller 401 may be, for example, but not limited to, a microprocessor or any other suitable processing device. Further, while in the exemplary embodiment, function (1) is not controlled by microcontroller 401, it is understood that in alternative embodiments function (1) may also be controlled by microcontroller 401. Also, in the illustrated embodiment, the PVM circuit breaker 400 also includes an indicator function (labeled (5)) controlled by the microprocessor 401 to indicate information such as a fault condition and/or current flowing through the PVM circuit breaker 400.

Before proceeding with a detailed description of the individual or elements and operation of the system 200 according to an exemplary embodiment, an exemplary implementation of the PVM circuit breaker 400 as shown in U.S. patent application publication nos. 2014/0211345 and 2014/0214218 will be described in detail below with reference to fig. 5, 6, and 7.

The PVM circuit breaker 400 can support billing a user for energy consumed by the PVM circuit breaker 400. For example, the metering function 402 (fig. 5) uses the logic circuitry 404 (fig. 5 and 6) to store the time-stamped energy value 406 in a persistent database 408 in memory 410. The metering function 402 and the logic circuit 404 are both within the housing of the PVM circuit breaker 400. In some timestamps, the energy value 406 may be "marked" as belonging to several particular users, which provides an energy allocation for each of these several particular users. For example, when an electrical load 412 (shown in dashed line drawing) is plugged in, energy can be distributed to a particular power circuit as appropriate (e.g., to the electrical load 412 at terminals 414, 416 (shown in dashed line drawing in fig. 5)).

A power supply, such as a power utility 418 (shown in dashed line drawing in fig. 5 and 6), supplies power to a breaker tab 420 (e.g., from a live line or bus (not shown)) and a neutral tap 422 (e.g., to a neutral bus (not shown)) at a distribution board or load center (not shown), which can be charged to a user in various ways when the power supply is ready for use, either by via an expansion port 424 (fig. 6) or alternatively by a built-in wireless interface (e.g., without limitation Wi-Fi; bluetooth). One exemplary method is a "meter reading" of the total energy when reading from a main circuit breaker (not shown, but which may be substantially the same or similar to the circuit breaker 400 except having a relatively large rated current value) of a corresponding distribution board or load center (not shown). The value of the "meter reading" is compared to the value of the "meter reading" from, for example, a reading of the previous month, and the difference is billed.

Alternatively, the power utility 418 can download all of the databases 408 for each circuit breaker (such as 400), query the energy values 406 as appropriate, and then apply the appropriate rate structure using the time stamp, the particular circuit, and any assigned flags.

Fig. 5-7 illustrate an exemplary controllable PVM circuit breaker 400 that can include optional support components for communication and/or several different add-on modules 426, as will be discussed.

Referring to fig. 5, the exemplary PVM circuit breaker 400 can include several optional additional modules 426. The Alternating Current (AC) electrical path through the PVM circuit breaker 400 between the power source 418 and the load 412 includes a thermal-magnetic protection function 428, a metering function 402, and controllable separable contacts 430. The AC-DC power supply 432 supplies DC power to, for example, the logic circuit 404 and the communication circuit 434. Alternatively, the DC power source 432 may be located external to the PVM circuit breaker 400 and supply DC power thereto. Several optional additional modules 426 may provide specific logic and/or I/O functionality and communication circuitry 436. Optional remote software functions 438, 440 may optionally be in communication with the communication circuits 434, 436.

Fig. 6 shows further details of the exemplary PVM circuit breaker 400, which includes an external breaker handle 442, the handle 442 cooperating with the thermal-magnetic trip function 428 to open, close and/or reset the corresponding separable contacts 429 (fig. 7), an OK indicator 444 controlled by the logic circuit 404, and a test/reset button 446 input to the logic circuit 404.

In this example, the live and neutral wires pass through the PVM circuit breaker 400 and the respective current sensors 448, 449, voltage sensors 450, 451, and separable contacts 430A, 430B of each wire or electrical conductor. The power metering circuit 452 of the metering function 402 inputs and outputs respective power values from the current sensors 448, 449 and the voltage sensors 450, 451 to the logic circuit 404, which uses the timer/clock function 454 to provide the respective time-stamped energy values 406 in the database 408 of the memory 410. The current sensors 448, 449 may be electrically connected in series with the respective separable contacts 430A, 430B, may be current transformers coupled to the power line, or may be any suitable current sensing device. The voltage sensors 450, 451 may be electrically connected to the respective power lines in series with the respective separable contacts 430A, 430B, may be voltage transformers, or may be any suitable voltage sensing device.

Figure 7 is an exemplary single line diagram of an exemplary PVM circuit breaker 400. Although one phase (e.g., a live line and a neutral point) is shown, the disclosed concepts are applicable to PVM circuit breakers having any number of phases or poles. The live line is received through a terminal 420 to a bus bar (not shown). Current flows through a first disconnect element 429 of the thermal-magnetic overload protection function 428 and through a set of controllable separable contacts 430 (only one set of live line contacts is shown in this example) to the load terminal 414. A first Current Transformer (CT)448 provides current sensing and ground fault detection with customizable trip settings. A return current path from the load 412 (fig. 5) is provided from the load end 416 for the load neutral point back to the neutral tap 422 for electrical connection to a neutral line, for example, of a distribution board or load center (not shown). The second CT 449 provides current sensing and ground fault detection with customizable trip settings. The outputs of the CTs 448, 449 are input by the logic circuit 404, and the logic circuit 404 controls the controllable separable contacts 430. Power supply 432 receives power from the live and neutral lines. The logic circuit communication circuit 434 also outputs to a communication endpoint 456 (fig. 6) of the expansion port 424.

Referring again to FIG. 2, elements of a system 200 according to a non-limiting exemplary embodiment will now be described. System 200 includes a mains power supply 205 coupled to a primary meter 210. Load center 215 is coupled to the output of main meter 210 for receiving utility power from the utility grid of utility power source 205. The load center 215 includes a main circuit breaker 220 coupled to the main meter 210. In an alternative embodiment, the primary meter 210 may be omitted, with the load center 215 connected directly to the mains supply 205. In any such alternative embodiment, the metering function may instead be provided by the main circuit breaker 220, the main circuit breaker 220 being configured with such a metering function as described below.

The load center 215 also includes a main bus bar 225 and a number of branch circuit breakers 230 coupled to the main bus bar 225. As can be seen in fig. 2, each branch circuit breaker 230 is coupled to an associated load or loads 235. In the illustrated exemplary embodiment, the load center 215 feeds a dedicated circuit, meaning that each branch circuit breaker 230 feeds a single load 235 and is coupled to a single load 235 (however, each load 235 is not necessarily a dedicated circuit). However, it is to be understood that this is intended to be exemplary only, and that other configurations, in which non-dedicated circuitry and/or a combination of dedicated and non-dedicated circuitry may also be used within the scope of the disclosed concept. The load center 215 also includes an LER circuit breaker 240 having a local power generation source 245 coupled thereto. The local power generation source 245 may be any type of distributed power source, such as, but not limited to, a distributed power source using PV modules, generators, wind turbines, natural gas turbines, or battery storage.

In the non-limiting illustrated exemplary embodiment, the main breaker 220, the branch breaker 230, and the LER breaker 240 are each PVM breakers 400, which are described in detail elsewhere herein. Thus, each of these circuit breakers has a circuit protection function, a branch circuit metering function, a remote control function, and a communication function as described herein (fig. 4).

Also, as seen in fig. 2, the load center 215 includes a control assembly 250. The control assembly 250 is configured to control the operation of the system 200 as described herein, and in particular is configured and programmed to implement the control method illustrated in fig. 3 and described in detail below. The control assembly 250 may reside anywhere within the load center 215, such as within the main breaker 220, the branch breaker 230, the LER breaker 240, or may be extended and distributed across one or more of these elements. In an alternative embodiment, the control component may be a computing device having a processor and programmable memory plugged into the load center 215. In yet another alternative embodiment, the control components may be located remotely from the load center 215, still in communication with or controlling aspects of the load center 250 as described herein. In the exemplary embodiment described herein, for purposes of illustration, the control assembly 250 forms a portion of the main circuit breaker 220 to enable the main circuit breaker 220 to act as a system coordinator for the load center 215.

Referring to fig. 3, a control method according to the disclosed concept of an exemplary embodiment will now be described. The method starts at step 300, wherein a power outage at the mains power supply 205 is detected. In an exemplary embodiment, this outage is detected by the main circuit breaker 220 by sensing that the voltage from the mains power supply 205 has dropped below some predetermined level. Next, at step 305, the control component 250 opens the main breaker 220 to isolate the load center 215 and the local power generation source 245 from the main grid of the mains power supply 205. Then, at step 310, the control assembly causes the LER breaker 240 to be opened by transmitting a control signal (via a suitable wired or wireless connection) to the LER breaker 240. Alternatively, the order of steps 305 and 310 may be swapped, such that step 310 is performed first, followed by step 305. Next, at step 315, the control component 250 identifies which, if any, of the branch breakers 230 will not receive backup power from the local generation source 245. This step may be performed in various ways and includes determining which circuit breakers are to receive backup power and which circuit breakers are not to receive backup power based on one or more stored and/or measured parameters and/or functions. For example, control component 250 may be programmed to identify certain predetermined loads (i.e., "critical loads") of loads 235 that are to receive backup power in the event of a power outage, and thus at step 315, loads 235 that are not "critical loads" will be identified. The programming and identification of "critical loads" in this particular implementation may be made by the local user of the utility and/or load center 215, and thus, this aspect of the disclosed concept provides great flexibility in backup power supply by allowing dynamic load management in outage conditions. The programming and identification of "critical loads" may also be prioritized such that when a power outage is detected, the load 235 will be selected to receive backup power based on the power available according to a predetermined priority. Alternatively, control component 250 may be programmed to dynamically select those of loads 235 that are to receive backup power based on predetermined parameters (such as time and/or date) based on which certain loads 235 are identified for receiving backup power based on the current state. Also, many additional alternative control schemes are possible. For example, in one alternative control scheme, each load 235 is previously identified as "critical" or "non-critical," and the control component 250 cooperates with the metering data measured by the associated branch circuit breaker 230 to ensure that as many "critical" loads as possible are made operational without overloading/over-fatiguing the local generation source 245 (i.e., without exceeding the supply capacity of the local generation source). In another alternative control scheme, each load 235 is assigned a priority, e.g., "1" is the highest priority, and so on. The control component 250 then cooperates with the metering data measured by the associated branch circuit breaker 230 to ensure that as many of the highest priority loads 235 are operational as possible without overloading/over-fatiguing the local power generation source 245. Thus, the first exemplary scheme provided above is basically a two priority example of this second control scheme. In yet another alternative control scheme, each load 235 is assigned a priority and preferred "run time". The control component 250 then cooperates with the metering data and the time data to ensure that as many highest priority loads 235 as possible are operable for their particular run times, and at the end of the run time of a load 235, other lower priority loads 235 may have their associated branch circuit breakers 230 closed. In yet another alternative control scheme, the control assembly 250 may implement any of the above schemes, whereby a user may select a particular branch circuit breaker 230 to be opened and/or closed via a "user override" assembly.

After step 315, the method proceeds to step 320, wherein the control assembly 250 causes the branch circuit breaker 230B identified in step 315 to be opened. Next, at step 325, control component 250 causes a signal to be sent to local power generation source 245 (using appropriate wired and/or wireless connections between these components), which causes local power generation source 245 to be activated. Next, at step 330, the control component 250 causes the LER breaker 240 to be closed by causing a signal to be sent to the LER breaker 240 (using appropriate wired and/or wireless connections between these components). After step 330, the method proceeds to step 335, where the system 200 can operate on power from the local power generation source 245, which is provided to any loads 235 that were not identified in step 315.

At step 340, a determination is made as to whether utility power at the utility power source 205 has been restored. If the answer is negative, the method returns to step 335. At this point, a user of the load center 215 may reconfigure the system using the control assembly 250 to change the branch circuit breaker 230 and also the load 235 receiving power being open (or closed). For example, if in the event of a power outage, the user determines that they now require a load 235 that was initially determined to be "non-critical" or low priority, the user can now close the circuit and, if desired, open another circuit of lower priority in order to prevent excessive fatigue of the local power generation sources 240 (as described below). For example, if a user determines that they need to recharge an EV that was initially determined to be "non-critical," the user may choose to temporarily turn off their air conditioning unit in order to allow charging of their EV. Then, once the EV has been sufficiently charged, the user may choose to turn off the EVSE, turning back on its air conditioning unit. This provides the user with a great deal of additional flexibility and plasticity not provided by conventional systems. It should be noted, however, that the connected loads 235 are managed/matched so as not to over-fatigue the capacity of the local generation source 245 and either trip its feedback breaker or over-fatigue it to the point of failure. In the exemplary embodiment, control component 250 includes control features that facilitate management and matching of loads 235 in order to prevent excessive fatigue of local power generation sources 245. For example, prior to making any changes, the control component 250 may examine the metering data and determine what impact the changes will have on the load demand and prevent any changes that may lead to an over-fatigue condition. However, if the answer at step 340 is affirmative, the method proceeds to step 345, where the control component 250 causes the LER breaker 240 to be opened. Next, at step 350, control component 250 causes local power generation source 245 to be deactivated. Thereafter, at step 355, the control assembly 250 causes the main circuit breaker 220 to be closed. Then, at step 360, the control assembly 250 causes all of the branch breakers 230 to be closed by sending one or more signals to those branch breakers 230 (using appropriate wired and/or wireless connections between the components). Alternatively, the order of steps 355 and 360 may be swapped such that step 360 is performed first followed by step 355. Finally, at step 365, the control component 250 causes the local power generation source 245 to be activated so that the local power generation source 245 can return to the back-fed mains power supply 205 now that the outage has been corrected.

Thus, the method shown in fig. 3 and described above provides a safety mechanism that switches to backup power via a local power generation source in the event of a power outage, returning utility power after the outage, which does not require a costly, complex and inflexible switching mechanism, such as an ATS (fig. 1).

Moreover, although the system 200 shown in fig. 2 and the method described with respect to fig. 3 includes only a single local power generation source 245, it is to be understood that the disclosed concept may also be used in a system that includes multiple local power generation sources 245 and multiple LER breakers 240. In such alternative implementations, the method as implemented in control component 250 may need to ensure that multiple local power generation sources 245 are able to synchronize with each other. In an exemplary embodiment, a local power generation source 245 would be promoted to become "utility" and would be connected to the main bus 225. The local power generation source 245 then provides a wetting voltage (wetting voltage) to other local power generation sources 245 in synchronization therewith. In another alternative embodiment, the control component 250 is configured with metadata about the local power generation source 245, such as weather data for a solar embodiment or fuel capacity for fuel consumption for a generator embodiment, and the metering data received from the branch circuit breaker 230 may be used to predict "remaining uptime" of how long the local power generation source 245 can continue to provide power to the connected load 235. Load management decisions can be made more intelligently by the addition of metadata from which important statistics (such as, but not limited to, "remaining uptime") can be derived.

In yet another alternative embodiment, the local power generation sources 245 shown in fig. 2 may not be provided at a customer location (such as a residence), but rather are local power generation sources within a power distribution system (e.g., "neighborhood" local power generation sources) intended for a group of utility customers. For example, local power generation source 245 may be a local energy storage device (e.g., a battery) configured to service a number of customers in a particular area if a power outage occurs. In such a configuration, one or more customers may have a load center 215 as described herein, the load center 215 having an LER breaker 240 coupled to a "neighbor" local power generation source 245. Thus, as described herein, each customer having such a load center 215 is able to determine which loads 215 will receive backup power from the "neighbor" local generation source 245 in the event of a power outage. Further, in the exemplary embodiment, since main breaker 220, LER breaker 240, and branch breaker 230 are each PVM breakers 400 with metering functionality as described herein, a utility providing a "neighbor" local generation source 245 will be able to bill customers for their usage. In one example, customer usage may be unlimited, and the customer will pay for any electricity consumed. In another embodiment, a customer may subscribe (and pay) a certain amount of backup power in the event of a power outage, and their access to "neighbor" local generation sources may be limited to the amount of power covered by their subscription (i.e., LER breaker 240 may be opened once the subscribed amount of power has been consumed). In such a case, the customer may wish to actively manage the loads 235 of the load center 215 as described herein in order to meter the power they may obtain.

While specific embodiments of the disclosed concept have been described in detail, it will be appreciated by those skilled in the art that various modifications and alternatives to those details could be developed in light of the overall teachings of the disclosure. Accordingly, the particular arrangements disclosed are meant to be illustrative only and not limiting as to the scope of the disclosed concept which is to be given the full breadth of the appended claims and any and all equivalents thereof.

Claims (13)

1. An apparatus (215) for managing an electrical system (200), comprising:

a main circuit breaker (220) configured to be coupled to a mains power supply (205);

an LER breaker (240) structured to be coupled to a local power generation source (245);

a number of branch circuit breakers (230), each branch circuit breaker being structured to be coupled to one or more loads (235) and including a metering function for metering an amount of electrical power consumed therethrough; and

a control component (250) constructed and arranged to, in response to a determination that the mains power supply is experiencing a power outage:

causing the main circuit breaker to be opened;

receiving metering data measured by each of the number of branch circuit breakers;

determining which one or more of the number of branch breakers are to receive backup power from the local power generation source based at least in part on the received metering data;

configuring the branch circuit breakers such that only one or more of the determined number of branch circuit breakers are in a closed condition; and

causing the local power generation source to be activated;

wherein the metering function is configured to store the time-stamped energy value to provide an energy allocation for a user;

wherein the control component is constructed and arranged to cause the LER breaker to be opened prior to determining which one or more of the number of branch breakers are to receive backup power from the local generation source, and to cause the LER breaker to be closed after the local generation source is activated;

wherein the control component is constructed and arranged to, in response to a determination that a power outage has ended, cause the LER breaker to be opened, cause the local power generation source to be deactivated, cause the main breaker to be closed, cause all of the number of branch breakers to be closed, and cause the local power generation source to be activated;

wherein the local power generation source is located at a different location than the one or more loads (235) and is configured to bill for power consumed by the one or more loads (235).

2. The apparatus of claim 1 wherein each of said main circuit breaker, said LER circuit breaker and said branch circuit breaker includes a remote control function for operating controllable contacts thereof, a communication function for sending and receiving information, said metering function and a circuit protection function including thermo-magnetic circuit protection.

3. The apparatus of claim 1, wherein the control component is to: (i) is provided as part of the main circuit breaker, (ii) is provided as part of one of the LER circuit breaker or the branch circuit breaker, (iii) is provided remotely from each of the main circuit breaker, the LER circuit breaker and the branch circuit breaker, or (iv) is distributed across two or more of the main circuit breaker, the LER circuit breaker and a number of the branch circuit breakers.

4. The apparatus of claim 1, wherein the control component is structured and configured to cause the LER breaker to be opened after the main breaker is opened, and wherein the control component is structured to cause an LER breaker to be closed after the local power generation source is activated.

5. The apparatus of claim 1, wherein the control component is structured and configured to determine which one or more of the number of branch circuit breakers are to receive backup power from the local generation source based on the received metering data and the stored predetermined identification of the ones of the number of branch circuit breakers.

6. The apparatus of claim 1, wherein the control component is constructed and arranged to determine which one or more of the number of branch breakers are to receive backup power from the local power generation source based on the received metering data and a stored predetermined priority of the one or more loads.

7. The apparatus of claim 1, wherein the control component is structured and configured to determine which one or more of the number of branch breakers are to receive backup power from the local power generation source based on the received metering data and one or more predetermined parameters measured, determined or received by the control component.

8. The apparatus of claim 1, wherein the control component is constructed and arranged to determine which one or more of the number of branch breakers is to receive backup power from the local generation source when the local generation source is activated by selecting one or more of the number of branch breakers in a manner that ensures that a load demand through the one or more of the number of branch breakers does not exceed a supply capacity of the local generation source.

9. The apparatus of claim 1, wherein the control component is structured and configured to determine which one or more of the number of branch circuit breakers are to receive backup power from the local power generation source based on the received metering data and a stored predetermined priority assigned to each of the number of branch circuit breakers.

10. The apparatus of claim 1, wherein the control component is further constructed and arranged to ensure that a maximum number of the branch breakers receive backup power without exceeding a supply capacity of the local generation source when the local generation source is activated, and wherein one or more of the number of branch breakers to receive backup power is determined based on the received metering data and a stored predetermined priority assigned to each of the number of branch breakers.

11. The apparatus of claim 1, wherein the control component is structured and configured to determine which one or more of the number of branch breakers are to receive backup power from the local power generation source based on the received metering data and the stored predetermined priority and stored predetermined run time assigned to each of the number of branch breakers.

12. The apparatus of claim 1 wherein the control assembly is structured and configured to cause the electrical system to be reconfigured during a power outage and after the local power generation source is activated by receiving an identification of some of the branch breakers that are to receive power and other ones of the branch breakers that are not to receive power, and in response thereto, causing the branch breakers to be configured such that only the some of the branch breakers are in a closed condition.

13. A method for controlling an electrical system (200), the electrical system (200) including a main breaker (220) provided at a load center (215) and coupled to a mains power source (205), an LER breaker (240) provided at the load center and coupled to a local generation source (245), and a number of branch breakers (230) provided at the load center and each coupled to one or more loads (235) and configured with a metering function for metering an amount of power consumed therethrough, the method comprising:

determining in the load center that the mains power supply is experiencing a power outage;

in response to determining that the mains power supply is experiencing a power outage, causing the main circuit breaker to be opened by providing first communication information to the main circuit breaker;

receiving metering data measured by each of the number of branch circuit breakers;

determining which one or more of the number of branch breakers are to receive backup power from the local power generation source based at least in part on the received metering data;

configuring the branch circuit breakers such that only the determined one or more of the number of branch circuit breakers are in a closed condition by providing second communication information to the branch circuit breakers other than the one or more of the number of branch circuit breakers that are to receive backup power; and

causing the local power generation source to be activated by providing third communication information to the local power generation source;

wherein the metering function is configured to store the time-stamped energy value to provide an energy allocation for a user;

wherein the method further comprises: causing the LER breaker to be opened prior to determining which one or more of the number of branch breakers are to receive backup power from the local generation source and causing the LER breaker to be closed after the local generation source is activated;

wherein the method further comprises: in response to a determination that the outage has ended, causing the LER breaker to be opened, causing the local power generation source to be deactivated, causing the main breaker to be closed, causing all of the number of branch breakers to be closed, and causing the local power generation source to be activated;

wherein the local power generation source is located at a different location than the one or more loads (235) and is configured to bill for power consumed by the one or more loads (235).

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