Patent Application
20240162744
Embodiments of the present invention generally relate to distributed energy production and consumption systems (i.e., distributed energy resource (DER) systems) and, in particular, to a method and apparatus for identifying DER systems located behind a transformer within utility grid infrastructure.
A solar energy generation and storage system (Distributed Energy Resources (DERs)) typically comprises a number of components including, but not limited to, at least one energy source (e.g., solar panel and related power inverters), at least one storage element (e.g., battery system), at least one load (e.g., appliances) and/or at least one service panel to connect the DER components to the utility power grid. The solar panels are arranged in an array and positioned to maximize solar exposure. Each solar panel or small groups of panels may be coupled to an inverter (so-called micro-inverters) or all the solar panels may be coupled to a single inverter. The inverter(s) convert the DC power produced by the solar panels into AC power. The AC power is coupled to the service panel for use by a facility (e.g., home or business), supplied to the power grid, and/or coupled to a storage element such that energy produced at one time is stored for use at a later time. The at least one storage element may be one or more of batteries, fly wheels, hot fluid tank, hydrogen storage or the like. The most common storage element is a battery pack (i.e., a plurality of battery cells) having one or more bidirectional inverters coupled to the service panel to supply the batteries with DC power as well as allow the batteries to discharge through the inverter(s) to supply AC power to the facility when needed.
In addition, a number of components within a DER consume the generated power, e.g., load or consumption components such as appliances, electric vehicles, etc. Typically, the DER may be controlled by a controller to control loads and sources to locally balance energy production and consumption. Optimally, excess power produced by any individual DER system should be shared with energy consumers connected to the utility grid infrastructure. However, utility grid infrastructure interconnects a neighborhood of sites (homes and/or businesses). Within the infrastructure are power transformers that can be overloaded if too much power is coupled through the transformer. Typically, a group of sites are directly interconnected via low voltage transmission lines and site groups are connected to one another via transformers and high voltage transmission lines. Consequently, the transformers become bottlenecks in the transfer of power through the grid infrastructure.
To efficiently transfer energy between sites, it would be helpful to identify which sites are behind a transformer (e.g., connected directly with each other). Once the sites behind the transformer (BTT) are known, DER systems within the BTT group may transfer energy amongst themselves without regard to the transformer bottleneck.
Therefore, there is a need for a method and apparatus for identifying DER systems located behind the transformer.
A method and apparatus for identifying DER systems located behind the transformer is provided substantially as shown in and/or described in connection with at least one of the figures, as set forth more completely in the claims.
Various features and advantages of the present disclosure may be appreciated from a review of the following detailed description of the present disclosure, along with the accompanying figures in which like reference numerals refer to like parts throughout.
So that the manner in which the various features of the present invention can be understood in detail, a particular description of the invention, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.
Embodiments of the present invention comprise apparatus and methods for identifying DER systems located behind a transformer within a utility grid infrastructure. Embodiments of the invention comprise defining DER system groups (e.g., including groups of homes, business, apartment complexes, housing complexes, etc.), where each DER system within a DER group contains at least one local DER controller coupled to at least one load (e.g., electric appliances, electric vehicles, electric machinery, etc.) and at least one power producing asset (e.g., electric storage, solar panels, wind turbines, fuel cells, etc.). Since electric storage and electric vehicles may extract energy for storage as well as disgorge energy, these components may be viewed as behaving as both load and production assets. A DER group typically comprises a plurality of DERs that are connected to the utility power grid via a single transformer (e.g., a plurality of homes in a neighborhood that are connected to one another via the utility power grid infrastructure behind a transformer). The local DER controller(s) of DERs within a given group are capable of communicating to each other via power line communication (PLC) (i.e., each DER system comprises a PLC transceiver).
The PLC signals have a frequency, modulation and bandwidth that couples between DER systems but does not couple well through a utility grid transformer, i.e., the PLC signal is attenuated when transmitted through a grid transformer. In one embodiment, the PLC signals may have a carrier frequency of between 24 and 500 kHz, and, in a specific embodiment, use a carrier frequency of about 100 KHz. PLC signals may be modulated using amplitude modulation, Orthogonal Frequency Division Multiplexing (OFDM), Binary Phase Shift Keying (BPSK), Frequency Shift Keying (FSK), Spread-FSK (S-FSK) and the like. In other embodiments, other frequencies and modulation may be used. By monitoring the signal strength of a PLC signals transmitted amongst DER systems, embodiments of the invention are capable of determining which of the DER systems are behind the transformer (BTT).
The controller 110 comprises at least one processor 112, support circuits 114 and memory 116. The at least one processor 112 may be any form of processor or combination of processors including, but not limited to, central processing units, microprocessors, microcontrollers, field programmable gate arrays, graphics processing units, and the like capable of executing software instructions to cause the controller to perform the functions described herein. The support circuits 114 may comprise well-known circuits and devices facilitating functionality of the processor(s). The support circuits 114 may comprise one or more of, or a combination of, power supplies, clock circuits, communications circuits, cache, displays, and/or the like.
The memory 116 comprises one or more forms of non-transitory computer readable media including one or more of, or any combination of, read-only memory or random-access memory. The memory 116 stores software and data including, for example, control software 118 and data 120. Data 120 may comprise at least one database containing the identity of DER systems that are behind the transformer. The database may be updated with DER system identifiers as the controller 110 identifies such systems as described below.
The control software 116 may comprise software instructions that, when executed by the at least one processor 112, cause the controller to monitor the status of the DERs 122 and communicate with other DER systems 106 within the group 124. The control software 118 is also executed to enable the DER system 106 to detect which other DER systems 106 are located BTT. Details of the operation of the control software 118 to perform BTT detection is described with respect to
At 216, the method 200 analyzes the PLC signal. In one embodiment, the analysis involves measuring the signal strength of the received signal and comparing the signal strength to a threshold. If the PLC has passed through a transformer, the signal will be substantially attenuated. If the PLC is from a DER system that is BTT, the signal will be attenuated by the transmission losses of the wires and connections, but the attenuation will not be to the extent of the attenuation resulting from transmission through a transformer. Consequently, a signal from a DER system that is above the threshold is deemed BTT and below the threshold is not BTT. The PLC signal may contain a transmitting system identifier such that the receiving DER system can determine the identity of the DER system that is BTT. In this manner, the receiving DER system may update a BTT database with the identity of the transmitting DER system. With the knowledge that the transmitting DER system is BTT, the receiving system may exchange energy with the transmitting DER system because both systems are BTT.
At 218, the method 200 queries whether the PLC signal indicates BTT or not. If the signal is not BTT, the method ends at 222. If the PLC signal is deemed to be transmitted by a DER system that is BTT, the method 200 proceeds to 220. At 220, the method 200 transmits an acknowledgement (ACK) to the transmitting DER system. The ACK confirms to the transmitting DER system that the receiving DER system is BTT. Once the ACK is sent, the method ends for the second DER system at 222.
At 224, the method 200 receives the ACK at the first DER system. At 226, the method 200 updates the BTT database with the identity of the second DER system. The method 200 ends at 228.
All of the DER systems within a group transmit PLC signals to automatically determine which DER systems are BTT. The identity of the BTT systems are stored in a local database such that each DER system knows which other systems are BTT and eligible for energy transfer.
Here multiple examples have been given to illustrate various features and are not intended to be so limiting. Any one or more of the features may not be limited to the particular examples presented herein, regardless of any order, combination, or connections described. In fact, it should be understood that any combination of the features and/or elements described by way of example above are contemplated, including any variation or modification which is not enumerated, but capable of achieving the same. Unless otherwise stated, any one or more of the features may be combined in any order.
As above, figures are presented herein for illustrative purposes and are not meant to impose any structural limitations, unless otherwise specified. Various modifications to any of the structures shown in the figures are contemplated to be within the scope of the invention presented herein. The invention is not intended to be limited to any scope of claim language.
Where “coupling” or “connection” is used, unless otherwise specified, no limitation is implied that the coupling or connection be restricted to a physical coupling or connection and, instead, should be read to include communicative couplings, including wireless transmissions and protocols.
Any block, step, module, or otherwise described herein may represent one or more instructions which can be stored on a non-transitory computer readable media as software and/or performed by hardware. Any such block, module, step, or otherwise can be performed by various software and/or hardware combinations in a manner which may be automated, including the use of specialized hardware designed to achieve such a purpose. As above, any number of blocks, steps, or modules may be performed in any order or not at all, including substantially simultaneously, i.e., within tolerances of the systems executing the block, step, or module.
Where conditional language is used, including, but not limited to, “can,” “could,” “may” or “might,” it should be understood that the associated features or elements are not required. As such, where conditional language is used, the elements and/or features should be understood as being optionally present in at least some examples, and not necessarily conditioned upon anything, unless otherwise specified.
Where lists are enumerated in the alternative or conjunctive (e.g., one or more of A, B, and/or C), unless stated otherwise, it is understood to include one or more of each element, including any one or more combinations of any number of the enumerated elements (e.g. A, AB, AC, ABC, ABB, etc.). When “and/or” is used, it should be understood that the elements may be joined in the alternative or conjunctive.
While the foregoing is directed to embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.
This application claims benefit to U.S. Provisional Patent Application Ser. No. 63/424,637 filed 11 Nov. 2022 entitled “Method and Apparatus for Identifying Distributed Energy Resource Systems Located Behind a Transformer within Utility Grid Infrastructure,” which is hereby incorporated herein by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 63424637 | Nov 2022 | US |
