Ultrasonic Battery Management System (U-BMS), Energy Storage System using U-BMS

Abstract

The energy storage system may include a stack of multiple battery modules, multiple ultrasonic emitter transducers, multiple ultrasonic receive transducers, one or more excitation modules, one or more capture modules, and an ultrasonic battery management system. Each ultrasonic emitter transducer and each ultrasonic receive transducer may be acoustically coupled to a surface of a respective one of the battery modules. The excitation module(s) may be electrically interfaced with the multiple ultrasonic emitter transducers, and the capture module(s) may be electrically interfaced with the multiple ultrasonic receive transducers. The ultrasonic battery management system controller may be configured to initiate an ultrasonic interrogation sequence of the battery modules.

Description

[Technical field]

[0001] (CROSS REFERENCE TO RELATED APPLICATIONS) This application claims the benefit of and priority under 35 USC §119(e) to U.S. Provisional Application No. 63 / 210,413, entitled “Ultrasound-Battery Management Systems (U-BMS) and Energy Storage Systems Employing U-BMS,” filed June 14, 2021, and is hereby incorporated by reference in its entirety.

[0002] (Copyright Notice) A portion of the disclosure of this patent document may contain material that is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction of this specification or patent disclosure as it appears in the U.S. Patent and Trademark Office files or records, but otherwise reserves all copyrights whatsoever. This document is subject to the following notice: "Copyright (c) <2021 2022>, Titan Advanced Energy Solutions Inc.

[0003] (Field) The present disclosure relates generally to monitoring one or more energy storage devices, such as one or more batteries, and more particularly to ultrasound-based management of multiple energy storage devices. [Background technology]

[0004] Existing methods for managing an Energy Storage System (ESS) are based on monitoring the instantaneous voltage, current, and temperature of each battery module during charge and discharge cycles. A Battery Management System (BMS) interfaces with a Cell Interface (CI) module associated with each battery module and receives a stream of voltage, current, and temperature measurements from a sensor corresponding to the Cell Interface (CI). The ESS includes multiple individual battery modules that can be connected in series or parallel. Each battery module can include a single battery cell or multiple battery cells. The battery cells may be enclosed within a sealed pouch that includes battery terminals extending therefrom. One or more battery cells or pouches can be inserted into a more rigid battery module container or housing that can be filled with a liquid electrolyte and sealed. The battery cells can be interconnected in series, parallel, or a combination of series and parallel connections. The sealed container (e.g., battery module) can include battery terminals extending therefrom. The ESS configuration is selected to provide an ESS that meets the desired requirements of energy storage capacity, energy output characteristics, operating voltage, and current range. Multiple battery modules connected in series are known as a battery stack. An ESS configuration can include one or more battery stacks interconnected in series, parallel, or both.

[0005] Battery module charge balancing is used to uniformly charge and discharge all battery modules of an ESS. It is desirable for each battery module of an ESS to always have the same State of Charge (SoC). Furthermore, it is desirable for the battery modules not to be overcharged or overdischarged during charge and discharge cycles, as either condition can damage the battery module and / or lead to battery failure, thermal runaway, or other dangerous battery conditions. A number of factors hinder or complicate charge balancing when charging or discharging multiple battery modules. In a conventional stack of battery modules, where each battery module contains multiple battery cells, all battery modules are connected in series and therefore, in theory, have the same current flowing through them. However, a problem with conventional battery stacks is that not all battery modules store the same amount of energy. One reason for this is that the internal resistance of the battery modules varies from one battery module to another. The difference in internal resistance is due, in part, to differences in battery components, such as chemical differences, variations in thickness of material layers, and mechanical defects, which potentially contribute to differences in battery internal resistance. As a result, each battery module in the stack will receive a slightly different amount of useful charge, making the SoC of the individual stack batteries uneven or "unbalanced"; to ensure that the battery modules connected in the stack operate consistently and stay within desired voltage limits, the battery modules undergo charge balancing by attempting to equalize the measured battery voltages across all battery modules.

[0006] However, the battery voltage vs. SoC curve is nonlinear and the voltage range between a fully discharged battery module and a fully charged battery module is small, so the measured voltage alone is not a reliable indicator of the actual SoC. For example, the open circuit voltage (OCV) of a Li-ion battery module is directly related to the SoC, but not to the charging energy delivered to the battery module. The overall voltage range vs. SoC of an exemplary Li-ion battery module is as follows: At zero SoC (e.g., fully discharged), the OCV is about 5.0V. At 100% SoC (e.g., fully charged), the OCV is about 8.5V and the total voltage range is 3.5V. Thus, even if the voltage vs. SoC curve were linear, a 1% change in SoC would be associated with a voltage change of 0.04V, which may not be reliably measured. Furthermore, both the battery voltage and SoC change with changes in battery temperature. For the same exemplary Li-ion battery module, the nonlinear aspects of the voltage vs. SoC curve can be divided into three zones, namely, 0-20% SoC, 20-80% SoC, and 80-100% SoC. The 0-20% SoC range corresponds to the largest change in OCV. Over the 0-20% SoC range, the battery voltage range is about 5.0V-7.5V, or about 71.5% of the full voltage range. Over the 20-80% SoC range, the OCV range is about 7.5V-7.8V, or about 8.5% of the full voltage range. Over the 80-100% SoC range, the OCV range is 7.8V-8.5V, or about 20% of the full voltage range. Given the nonlinear nature of the voltage vs. SoC curves of many types of batteries, the change balance is applied only when the battery module is nearly fully charged (e.g., when the battery voltage is about 7.8V or about 80% charged). However, using only charge balance for the final 20% of the SoC range does not provide enough charge balance cycles to achieve full charge balance, and as a result, some battery modules may not reach the 100% SoC level and / or the charge capacity of some battery modules may remain unchanged.

[0007] A conventional ESS may include a stack switching gear (SG) module and a CI module coupled to a conventional BMS. The SG module is disposed between a power exchange module (e.g., a power source or a power load interface) and the ESS stack. The SG, CI, and BMS operate to manage the charge and discharge cycles of the stack and the charge balancing of the stack. Charge balancing includes a module configured to selectively unbalanced charge or discharge one or more battery modules during charge and discharge cycles to match all battery module measurement voltage values ​​with the average battery module voltage of the battery stack. The SG module limits the current amplitude by applying resistors arranged to divert energy from targeted battery modules to reduce or increase the battery voltage compared to the average battery module voltage of the battery stack. In practice, conventional BMS and SG modules are balanced and in equilibrium only when the battery module voltages are approximately 80-85% charged.

[0008] A conventional BMS can monitor functional energy storage device parameters, e.g., current, voltage, temperature by CI, and can calculate or infer performance metrics, e.g., SoC, State of Health (SoH), and energy storage capacity, based on battery voltage alone. A conventional BMS can track and communicate the status of each battery module to an external system, e.g., a power exchange module. A conventional BMS can attempt to protect the battery from harmful conditions, e.g., overcharge, overdischarge, overtemperature, overvoltage, or current conditions. To ensure that the battery operates within safe electrochemical limits, a conventional BMS imposes voltage limits that serve as boundaries for battery operation. Because a conventional BMS cannot directly measure SoC and SoH, it uses voltage and current measurements of each battery module to calculate battery capacity metrics (e.g., SoC, SoH) to understand the available energy capacity within the voltage limits. Summary of the Invention [Problem to be solved by the invention]

[0009] However, this practice may result in some battery modules never reaching 100% SoC level, leaving available ESS stack charge storage capacity unused.

[0010] Embodiments of the disclosed subject matter may address, among other things, one or more of the problems and shortcomings set forth above. [Means for solving the problem]

[0011] Embodiments of the disclosed subject matter provide systems, devices, and methods for managing an energy storage system (ESS) comprising a plurality of energy storage stacks (e.g., battery stacks) by using ultrasonic measurements of the stacks and / or individual units (e.g., batteries) therein. The ESS system may include a battery stack. Each battery module of the battery stack may be acoustically coupled to an ultrasonic emitter (e.g., transducer) and / or ultrasonic receiver (e.g., transducer). In some embodiments, an ultrasonic BMS module may be operable to manage the battery stack and capture periodic ultrasonic interrogation data corresponding to each battery of the battery stack. A processing module may determine a state of charge (SoC) value and / or a state of health (SoH) value of one, some, or all units of the stack. In some embodiments, a battery charge balancing module coupled to the stack may be operable to selectively limit current flow to and / or from selected units of the stack based at least in part on the determined SoC and / or SoH values.

[0012] Embodiments of the disclosed subject matter can provide a closed-loop solution for making physics-based charge capacity measurements, for example, by determining SoC and / or SoH based at least in part on periodic ultrasonic signatures of each module (e.g., battery module) of an ESS stack (e.g., battery stack). In some embodiments, the ultrasonic signatures can be generated by coupling one or more ultrasonic transducers (e.g., transceivers) to each battery module of the stack and electrically connecting each ultrasonic transducer to an ultrasonic-based battery management system (U-BMS). The ultrasonic transducers can include ultrasonic emitters acoustically coupled to a surface of the battery module and emitting ultrasonic energy to the corresponding battery module. Alternatively or additionally, the ultrasonic transducers can include ultrasonic receivers acoustically coupled to a surface of the same battery module. The ultrasonic receivers can receive the ultrasonic energy that has passed through the battery module and can generate an electrical signal representative of the received ultrasonic energy.

[0013] In some embodiments, physics-based capacity measurements of SoC and SoH are derived by one or more SoC / SoH modules associated with the U-BMS. The SoC / SoH modules can determine the SoC and / or SoH values ​​by characterizing an ultrasonic signature. In some embodiments, the one or more SoC / SoH modules can be configured to determine the SoC and / or SoH values ​​independent of the instantaneous battery voltage. In some embodiments, an ultrasonic signature can be generated during a battery charge or discharge cycle. Such physics-based capacity measurements can improve the resolution and accuracy of the SoH and / or SoC values ​​compared to deriving the SoC and SoH from voltage measurements. By using the ultrasonically guided measurements described herein, embodiments of the disclosed subject matter are capable of charge balancing a stack of battery modules over a larger range of battery voltages than was possible with conventional techniques. By increasing the battery voltage range over which charge balancing of the battery modules can occur, the total charge capacity of the battery stack can be increased.

[0014] In a representative embodiment, the energy storage system may include a stack of battery modules, a plurality of ultrasonic emitter transducers, a plurality of ultrasonic receiver transducers, one or more excitation modules, one or more capture modules, and an ultrasonic battery management system controller. Each ultrasonic emitter transducer may be acoustically coupled to a surface of a respective one of the battery modules. Each ultrasonic receiver transducer may be acoustically coupled to a surface of a respective one of the battery modules. The one or more excitation modules may be electrically connected to the plurality of ultrasonic emitter transducers. The one or more capture modules may be electrically interfaced to the plurality of ultrasonic receiver transducers. The ultrasonic battery management system controller may be configured to initiate a battery module ultrasonic interrogation sequence.

[0015] In another exemplary embodiment, the method can include acoustically coupling an ultrasonic emitter transducer and an ultrasonic receiver transducer to a battery module of a stack of multiple battery modules. The method can further include electrically interfacing each ultrasonic emitter transducer with one or more excitation modules and electrically interfacing each ultrasonic receiver transducer with one or more capture modules. The method can also include initiating a battery ultrasonic interrogation sequence by an ultrasonic battery management system controller.

[0016] In another representative embodiment, a method for operating an energy storage system (ESS) to charge balance a stack of battery modules is provided. The method can include configuring the stack for ultrasonic interrogation of each battery module and capturing ultrasonic signal data corresponding to ultrasonic energy passing through each battery module. The method can also include processing the ultrasonic signal data by an SoC / SoH module, assigning a state of charge value to each battery module, and generating a charge balancing command based on the state of charge value associated with each battery module. The method can further include charge balancing the stack over an assigned state of charge value range of 15% to 100% during a stack charge cycle and / or charge balancing the stack over an assigned state of charge value range of 100% to 15% during a stack discharge cycle.

[0017] Any of the various innovations of the present disclosure can be used in combination or separately. This summary is provided to introduce in a simplified form a selection of concepts that are further described in the detailed description below. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter. The foregoing and other objects, features, and advantages of the disclosed technology will become more apparent from the following detailed description, which proceeds with reference to the accompanying drawings. [Brief description of the drawings]

[0018] The embodiments will now be described with reference to the accompanying drawings, which are not necessarily drawn to scale. Where applicable, some elements may be simplified or otherwise not shown to help illustrate and explain the underlying features. Like reference numbers refer to like elements throughout the drawings. [Figure 1] FIG. 1 is a schematic diagram of an energy storage system (ESS) including an ultrasonic battery management system (U-BMS) in accordance with one or more embodiments of the disclosed subject matter. [Diagram 2] FIG. 2 is a graph of example functions for a U-BMS in accordance with one or more embodiments of the disclosed subject matter. [Diagram 3] FIG. 3 is a graph of example functions for a U-BMS in accordance with one or more embodiments of the disclosed subject matter. [Figure 4] FIG. 4 is a graph of the energy storage capacity of a battery module stack versus the number of charge / discharge cycles, showing the balancing effect on increased stack capacity with the number of cycles. [Diagram 5] FIG. 5 illustrates a generalized example of a computing environment in which the disclosed technology can be implemented. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] General Considerations For purposes of this specification, certain aspects, advantages, and novel features of the disclosed embodiments are described herein. The disclosed methods and systems should not be construed as limiting in any way. Instead, the disclosure is directed to all novel and non-obvious features and aspects of the various disclosed embodiments, both alone and in various combinations and subcombinations with each other. The methods and systems are not limited to any particular aspects, features, or combinations thereof, and the disclosed embodiments do not require that any one or more particular advantages exist or problems be solved. Techniques from any embodiment or example can be combined with techniques described in any one or more of the other embodiments or examples. In view of the many possible embodiments to which the principles of the disclosed technology may be applied, it should be recognized that the illustrated embodiments are merely illustrative and should not be construed as limiting the scope of the disclosed technology.

[0020] Although some operations of the disclosed methods are described in a particular order for convenient presentation, it should be understood that this method of description encompasses reordering, unless a particular ordering is required by the specific language described below. For example, operations described in sequence may in some cases be reordered or performed simultaneously. Furthermore, for simplicity, the accompanying drawings may not show the various ways in which the disclosed methods may be used in conjunction with other methods. Furthermore, the description may use terms such as "provide" or "achieve" to describe the disclosed methods. These terms are high-level abstractions of actual operations that are performed. The actual operations that correspond to these terms may vary depending on the particular implementation and are readily discernible by those skilled in the art.

[0021] The disclosure of a numerical range should be understood to refer to each discrete point within the range, including the endpoints, unless otherwise indicated. Unless otherwise indicated, all numbers expressing amounts of ingredients, molecular weights, percentages, temperatures, times, and the like, used in this specification or claims should be understood to be modified by the term "about". Thus, unless otherwise implicitly or explicitly indicated, or unless the context is properly understood by those skilled in the art to have a clearer configuration, the numerical parameters described are approximations that may depend on the desired properties sought and / or the limits of detection under standard testing conditions / methods, as known to those skilled in the art. Whenever the embodiment numbers are directly and explicitly distinguished from the prior art discussed, the embodiment numbers are not approximations unless the word "about" is recited. Whenever "substantially", "approximately", "about", or similar language is expressly used in conjunction with a particular value, a variation of up to 10% of that value is intended, unless expressly stated otherwise.

[0022] Directions and other relative references may be used to facilitate the description of the figures and principles herein, but are not intended to be limiting. For example, certain terms such as "inside," "outside," "top," "bottom," "internal," "external," "left," "right," "front," "rear," "rear side," and the like may be used. Such terms are used, where applicable, to provide some clarity when dealing with relative relationships, particularly with respect to the illustrated embodiments. However, such terms are not intended to imply absolute relationships, positions, and / or orientations. For example, with respect to an object, "top" may become "bottom" by simply flipping the object over. Nevertheless, it is still the same part and the object remains the same.

[0023] As used herein, "comprising" means "including," and the singular forms "a" or "an" or "the" include plural references unless the context clearly dictates otherwise. The term "or" refers to a single element or a combination of two or more elements of the mentioned alternative elements unless the context clearly dictates otherwise. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items. The terms "includes," "comprises," "has," "including," "having," and / or "comprising," as used herein, specify the presence of described features, integers, steps, operations, elements, and / or components, but do not exclude the addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. Additionally, when an element, including a component or subsystem, is referred to and / or shown as being connected or coupled to another element, it will be understood that unless expressly stated otherwise, it may be directly connected or coupled to the other element or there may be intervening elements.

[0024] The various components, parameters, operating conditions, and the like described herein may be alternatives, but these alternatives are not necessarily equivalent and / or will function equally well. Nor is it meant to imply that the options are listed in order of preference, unless otherwise indicated. Any of the groups defined below may be substituted or unsubstituted, unless otherwise indicated.

[0025] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this disclosure belongs.Methods and materials similar or equivalent to those described herein can be used in the practice or testing of this disclosure, but suitable methods and materials are described below.The materials, methods, and examples are illustrative only and are not intended to be limiting.The features of the subject matter of this disclosure will become apparent from the following detailed description and the appended claims.

[0026] Terminology Overview The following is provided to facilitate a description of various aspects of the disclosed subject matter and to guide those of ordinary skill in the art in practicing the disclosed subject matter.

[0027] The following reference numbers are used throughout this description and the accompanying drawings unless otherwise stated:

[0028] [Table 1] TIFF2024525156000003.tif95170

[0029] Introduction As shown in FIG. 1, the ultrasonic battery management system (U-BMS) architecture can include a U-BMS control panel 0170, a U-BMS coordinator 0175, and one or more U-BMS controllers 0180, 0182 coupled to an energy storage system (e.g., batteries) to form an ultrasonically enabled energy storage system (U-ESS) 0100. In the illustrated example, the U-ESS 0100 includes two battery stacks 0105, 0110, although any number of battery stacks can be provided in accordance with one or more contemplated embodiments. In the illustrated example, the battery stack 0105 includes three battery modules 0115, 0120, 0125, and the battery stack 0110 includes three battery modules 0130, 0135, 0140. However, any number of battery modules can be included in each battery stack in accordance with one or more contemplated embodiments. In some embodiments, each battery module 0115-0140 can include at least one lithium-ion battery cell. In some embodiments, each battery module 0115-0140 may include four pouch cells housed within a rectangular metal casing. For example, in some embodiments, each battery module may be a Nissan Leaf® lithium-ion battery module with four pouch cells connected in a 2s-2p configuration. In some embodiments, the metal casing may include opposing parallel top and bottom walls, opposing parallel side walls, and opposing parallel end walls, all of which are joined together to form an airtight battery module housing.

[0030] In some embodiments, each battery module 0114-0140 can include positive and negative electrical terminals, each of which can be configured to connect the corresponding battery module to a respective power circuit 0150, 0152. In some embodiments, each power circuit 0150, 0152 can be electrically connected to a power exchange module 0155 via a respective switchgear (SG) module 0145, 0147. For example, the power exchange module 0155 can include a DC power bus that can interface with other power devices, such as power loads, power sources, other energy storage devices, power grid interfaces, photovoltaic-based energy generation systems, turbine-based energy generation systems, fuel cell energy storage systems, other external power distribution equipment, other power conditioned devices, or any combination of the foregoing.

[0031] In the illustrated example, the power circuit 0150 of the first battery stack 0105 electrically interconnects a first SG module 0145 in series with the plurality of battery modules 0115-0125 of the first stack 0105. The SG module 0145 also electrically connects the first battery stack 0105 with a power exchange module 0155. A first cell interface (CI) module 0160 can provide a sensor interface 0165 with each of the plurality of battery modules 0115-0125. In some embodiments, the CI module 0160 can include one or more voltage sensors, one or more current sensors, and / or one or more temperature sensors connected to the battery modules 0115-0125 to measure their instantaneous battery voltage, current, and / or temperature. In some embodiments, the voltage sensors and / or current sensors can be connected to the battery terminals. For example, the CI module 0160 can include a coulomb counting element operative to track lifetime charge and discharge cycle information corresponding to each battery module. Each of the SG module 0145 and the CI module 0160 may be directly or indirectly (e.g., via a wired or wireless connection) connected to one or more control modules, such as a BMS control panel 0170, a BMS coordinator module 0175, and / or a U-BMS controller 0180, 0182. The power circuits 0152 of the second battery stack 0110, the second SG module 0147, and / or the second CI module 0160 may be configured in a similar manner to the battery modules 0130-0140.

[0032] In the illustrated example, the BMS control panel 0170 can control each of the SG modules 0145, 0147, can communicate with the power exchange module 0155, and / or can receive sensor data from the CI modules 0160, 0162. In some embodiments, the BMS control panel 0170 can also manage charge balancing based on charge balancing commands. In some embodiments, the BMS coordinator 0175 can operate as an interface communication module for exchanging data and commands between the U-BMS modules, the BMS modules, and / or other modules or components of the U-ESS 0100. For example, in FIG. 1 , the U-BMS modules interfaced with the BMS coordinator 0175 include the U-BMS controller host 0195 and the SoC / SoH module 0250, and the BMS modules interfaced with the BMS coordinator 0175 (e.g., via the BMS control panel 0170) include the SG modules 0145, 0147, the CI modules 0160, 0162, and the power exchange module 0155.

[0033] In some embodiments, the BMS control panel 0170 and the BMS coordinator 0175 may each include a processor running on a corresponding processor, a memory module, a communication interface, and energy management schema elements. For example, in some embodiments, one, some, or all of the SG modules may comprise a switchgear module configured to manage charge balancing, e.g., stacked switchgear sold by Nuvation Energy, Inc. of Sunnyvale, California. In some embodiments, the BMS control panel 0170, the CI modules 0160, 0162, or both may be configured to manage a conventional charge balancing process. In some embodiments, in an operational mode, the BMS control panel 0170 may receive sensor data from each CI module 0160, 0162 and may transmit the sensor data to the U-BMS coordinator 0175 for storage, e.g., in the memory module 0190 of the respective U-BMS controller 0180, 0182. Alternatively or additionally, in some embodiments, the BMS control panel 0170 can receive power exchange information (e.g., charging or discharging, stack power input or output, etc.) from the power exchange module 0155 and can send the power exchange information to the U-BMS coordinator 0175. In some embodiments, the U-BMS coordinator 0175 can also receive SoC and SoH values ​​from the SoC / SoH module 0250 and can send the information to the corresponding stack U-BMS controller 0180, 0182. In some embodiments, the U-BMS coordinator 0175 can also receive charge balancing commands from the stack U-BMS controller 0180, 0182 and can send the charge balancing commands to the BMS control panel 0170 for delivery to the SG modules 0145, 0147.

[0034] In the example shown in FIG. 1, the second battery stack 0110 is configured similarly to that described above for the first battery stack 0105, although in some embodiments the second battery stack (or third or multiple battery stacks) can have a different configuration than the first battery stack (or other battery stacks in the U-ESS). In the illustrated example of FIG. 1, the second battery stack 0110 includes three battery modules 0130, 0135, 0140, a second SG module 0147 coupled in parallel to a power exchange module 0155, a second CI module 0162 interfaced with each battery of the second stack, and a second U-BMS controller 0182 corresponding to the second stack 0110. The second stack 0110 can interface with a control module similarly to that described above to receive sensor data from the second CI module 0162 and transmit the sensor data to the second U-BMS controller 0182 corresponding to the second battery stack. In some embodiments, the BMS control panel 0170 can interface with a U-BMS coordinator 0175 via the second SG module 0147 and the power exchange module 0155 to exchange command and control messages related to power distribution associated with the second stack 0110.

[0035] In the example shown in FIG. 1 , the BMS coordinator 0175 interfaces with each of the U-BMS controllers 0180, 0182 corresponding to the first and second battery stacks 0105, 0110. In some embodiments, the power distribution and battery balancing corresponding to each battery stack can be managed separately by two U-BMS controllers 0180, 0182. For example, each U-BMS controller 0180, 0182 can include a controller processor 0185 in communication with each of the memory 0190, excitation module 0235, capture module 0240, and / or host module 0195. In some embodiments, each host module 0195 can interface with the BMS coordinator 0175. In the illustrated example, each host module 0195 is coupled to a U-BMS coordinator 0175, a power exchange module 0155, and CI modules 0160, 0162 via SG modules 0145, 0147 to manage power distribution and battery balancing by each battery stack.

[0036] Ultrasound Signal Generation and Processing Architecture Referring again to FIG. 1 , each battery module 0115, 0120, 0125 of the first battery stack 0105 includes a respective first ultrasonic transducer 0205, 0210, 0215 acoustically coupled to a surface (e.g., top surface) of the corresponding battery module. The second ultrasonic transducers 0220, 0225, 0230 can be acoustically coupled to an opposing bottom surface of the corresponding battery module 0115, 0120, 0125. In some embodiments, each first ultrasonic transducer 0205-0215 ​​can be an ultrasonic emitting transducer electrically interfaced with an excitation module 0235 of the U-BMS controller 0180, and each second ultrasonic transducer 0220-0230 can be a receiving transducer electrically interfaced with a capture module 0240 of the U-BMS controller 0180. In some embodiments, the ultrasonic emitting transducer electrically connected to the excitation module 0235 and the ultrasonic receiving transducer electrically connected to the capture module 0240 can be positioned on opposing upper and lower battery module surfaces (e.g., aligned or offset from one another) or on the same battery module surface.

[0037] In some embodiments, one, some, or all of the transducers 0205-0230 can operate as an ultrasonic emitting transducer or as an ultrasonic receiving transducer, depending, for example, on whether the transducer is electrically interfaced with the excitation module 0235 or the capture module 0240 of the respective U-BMS controller. When the ultrasonic emitting transducer and the ultrasonic receiving transducer are arranged in an opposing configuration, ultrasonic energy can be delivered into the battery module in a transmission mode. During the transmission mode, ultrasonic energy emitted by the ultrasonic emitting transducer passes from a first surface of the battery module to an opposing second surface of the battery module, where a portion of the ultrasonic energy passes through the opposing second surface to excite the ultrasonic receiving transducer. Alternatively, in some embodiments, both of the pair of ultrasonic transducers can be coupled to the same surface of the battery module. In this configuration, a first one of the transducer pair can operate as an ultrasonic emitting transducer when electrically interfaced with the excitation module 0235, and a second one of the transducer pair can operate as an ultrasonic receiving transducer when electrically interfaced with the capture module 0240. When both the ultrasonic emitting transducer and the ultrasonic receiving transducer are acoustically coupled to the same surface of the battery module, ultrasonic energy can be delivered in an echo transmission mode. During the echo transmission mode, ultrasonic energy emitted by the ultrasonic emitting transducer passes from a first surface of the corresponding battery module to an opposing second surface of the corresponding battery module, where a portion of the ultrasonic energy passes through the opposing second surface and a portion of the ultrasonic energy is reflected from the opposing second surface. The ultrasonic energy reflected from the opposing second surface returns from the opposing second surface to the first surface where a portion of the ultrasonic energy passes through the first surface to excite the ultrasonic receiving transducer.Thus, the through-transmission mode corresponds to ultrasonic energy passing through the battery module once, and the echo through-transmission mode corresponds to ultrasonic energy passing through the battery module twice.

[0038] In some embodiments, the U-BMS controller 0180 may be configured to control and / or manage the ultrasound-emitting transducers 0205, 0210, 0215. For example, to emit ultrasound energy, the U-BMS controller processor 0185 may command one, some, or all of the ultrasound-emitting transducers connected to the excitation module 0235 to transmit an electrical excitation signal. In some embodiments, the electrical excitation signal generated by the excitation module 0235 may be a square wave having a constant positive voltage for a duration. Alternatively or additionally, in some embodiments, the electrical excitation signal generated by the excitation module 0235 may be a square wave having a constant positive voltage for a first duration and then a constant negative voltage for a second duration (where the second duration may be the same or different than the first duration).

[0039] In some embodiments, the electrical excitation signal generated by the excitation module 0235 can have a large ultrasonic frequency range with the center of the ultrasonic frequency range corresponding to the natural resonant frequency of the ultrasonic emitting transducer coupled to the excitation module 0235. For example, the electrical excitation signal can have a center frequency in the range of 100 kHz to 1.10 MHz, and a pulse duration in the range of 600 to 800 nanoseconds (ns). The center frequency range, pulse duration, and / or pulse morphology of the electrical excitation signal can depend on the characteristics of the emitting transducer and / or can vary depending on the size of the battery module, the type of battery module, and / or the geometry of the battery module.

[0040] In some embodiments, during a battery interrogation sequence, the electrical excitation signal generated by the excitation module 0235 may include a single electrical signal instance or multiple consecutive identical electrical signal instances separated in time. For example, a single electrical drive signal may be emitted 32-64 times in succession. In some embodiments, the time interval between identical electrical signal instances may exceed the time it takes for ultrasonic energy corresponding to a previous electrical signal instance to dissipate. In some embodiments, in response to a single electrical excitation signal, a single ultrasonic emitting transducer may emit ultrasonic energy into and through a corresponding battery module. While passing through the battery module, the ultrasonic energy may be modified (e.g., attenuated) as the ultrasonic energy is absorbed, reflected, and / or scattered by the internal and external structures of the battery module. For example, the ultrasonic energy may include harmonics of a center frequency and echoes of ultrasonic energy that are reflected one or more times through the battery module.

[0041] Upon exiting the battery module, the ultrasonic energy may excite a corresponding ultrasonic receiving transducer attached to the battery wall (e.g., the battery wall facing the ultrasonic emitting transducer). In response to the excitation, the ultrasonic receiving transducer may generate an electrical response signal that is received by the capture module 0240. Upon receiving the electrical response signal, the capture module 0240 modifies the electrical response signal (e.g., by amplifying, filtering, digitizing, cleaning, and / or otherwise modifying the electrical response signal) in preparation for analysis. In some embodiments, when a successive series of electrical excitation signals are delivered to the ultrasonic emitting transducer, the corresponding ultrasonic receiving transducer may be excited by multiple instances of ultrasonic energy exiting the battery module and may generate a series of electrical response signals corresponding to the successive series of electrical excitation signals. Upon receiving each electrical response signal, the capture module 0240 modifies the electrical response signal (e.g., by amplifying, filtering, digitizing, cleaning, and / or otherwise modifying the electrical response signal) in preparation for analysis.

[0042] In some embodiments, the capture module can associate each electrical response signal with a signal ID, a signal timestamp, a sequence number, etc. Alternatively or additionally, the capture module can associate each electrical response signal with non-ultrasound related data, such as measured battery temperature, measured battery voltage, measured battery current, battery ID, battery type, etc. In some embodiments, when a battery module is evaluated based on multiple electrical drive signals (e.g., when a group of 32 or 64 individual electrical response signals is received by the capture module 0240), the sequence of electrical response signals can be treated as a single data set. Upon receiving multiple electrical response signals, the capture module 0240 can optionally modify each individual electrical response signal (e.g., by amplifying, filtering, digitizing, cleaning, and / or otherwise modifying the individual electrical response signal). In some embodiments, characteristics of the individual electrical response signals can then be combined (e.g., by averaging, generating a root mean square (RMS) value, calculating a quadratic average, etc., corresponding to a group of 32 or 64 individual electrical response signals). In some embodiments, each captured data instance may be transmitted to a SoC / SoH module 0250 which may analyze the captured data instance and associate an SoC value and / or an SoH value with the captured data instance.

[0043] In some embodiments, each battery stack (e.g., stack 0105) may have associated therewith a plurality of ultrasonic emitting transducers (e.g., three transducers 0205, 0210, 0215 corresponding to the three battery modules 0115, 0120, and 0125), a plurality of ultrasonic receiving transducers (e.g., three transducers 0220, 0225, 0230 corresponding to the three battery modules 0115, 0120, and 0125), and a plurality of temperature sensing transducers (e.g., three sensors 0245 such as thermocouples or other thermal measurement devices corresponding to the three battery modules 0115, 0120, and 0125). In some embodiments, one, some, or all of the ultrasonic emitting transducers may be electrically interfaced with an excitation module 0235 of the respective U-BMS controller, and one, some, or all of the ultrasonic receiving transducers may be electrically interfaced with a capture module 0240 of the respective U-BMS controller. In some embodiments, one, some, or all of the temperature sensors 0245 can be in communication with a temperature module 0260 of a respective U-BMS controller. In some embodiments, the excitation module 0235, the capture module 0240, and / or the temperature module 0260 can be in communication with a stack processor 0185, which can be in communication with a stack host 0195. In some embodiments, the stack host 0195 can be interfaced with the SoC / SoH module 0250, the BMS coordinator 0175, the BMS control panel 0170, the power exchange module 0155, the SG module 0145, and / or the CI module 0160.

[0044] In some embodiments, the SoC / SoH module 0250 may include a server processor, a server memory, and / or a server network interface device in communication with the server processor. For example, the SoC / SoH module may be configured to analyze the captured data in the time domain, the amplitude domain, the energy domain, and / or the frequency domain using trained machine learning models and / or other analysis processes. In some embodiments, the captured data processing may include converting the captured data instances into root mean square (RMS) plots, Hilbert transform plots, Fourier transform plots, etc., which may then be analyzed and characterized. In some embodiments, when all the various analyses and data manipulations are considered, the SoC / SoH module 0250 may derive an SoC value and / or an SoH value corresponding to the captured data.

[0045] In some embodiments, the SoC / SoH module may include one or more machine learning models 0255 operated by the server processor. The machine learning module may be configured to recognize and analyze features and / or feature extractions of the captured data based on training data. In some embodiments, the features or feature extractions may include time data, e.g., time of flight, time of peak amplitude, time of harmonics, time of unexpected features, time of primary energy peak, time of secondary energy peak, time of maximum frequency, etc. Alternatively or additionally, in some embodiments, the features or feature extractions may include frequency data, e.g., frequency range, center frequency, harmonic frequency, unexpected frequency variation, etc. Alternatively or additionally, in some embodiments, the features or feature extractions may include peak amplitude energy, harmonic energy peaks, unexpected energy peaks, etc. Other features or feature extractions are possible in accordance with one or more contemplated embodiments.

[0046] After evaluating the captured data instance, the SoC / SoH module 0250 may assign an SoC value and / or an SoH value to the captured data instance. The SoC and / or SoH value corresponding to a single stack battery module may then be returned by the SoC / SoH module 0250 to the corresponding battery stack capture module 0240 for storage, for example, in a corresponding memory module 0190 of the U-BMS controller 0180, 0182.

[0047] How to manage your batteries FIG. 2 illustrates a method 0300 for ultrasonic interrogation of a battery module of an ESS. In some embodiments, the method 0300 can be implemented via ultrasonic interrogation of a battery module of an ESS, such as the ESS configuration of FIG. 1. The method 0300 can begin at process step 0305, where an interrogation of one or more battery modules is triggered. For example, in some embodiments, the stack processor of the U-BMS controller can trigger the battery module ultrasonic interrogation process by instructing an excitation module to generate an electrical excitation signal. The method 0300 can proceed to process step 0310, where ultrasonic energy can be generated. For example, in some embodiments, an electrical excitation signal can be generated (e.g., by the excitation module 0235) and transmitted to one or more of the ultrasonic emitter transducers (e.g., transducers 0205-0215). The electrical excitation signal can excite an ultrasonic emitting transducer, which then transmits ultrasonic energy to the respective battery module.

[0048] The method 0300 may proceed to process step 0315 where ultrasonic energy passes through each battery module (e.g., passes through the interior of each battery module 0115-0125). The method 0300 may proceed to process step 0320 where ultrasonic energy may be received. For example, in some embodiments, ultrasonic energy may exit each battery module and excite a corresponding ultrasonic receiving transducer (e.g., transducers 0220-0230). The method 0300 may proceed to process step 0325 where a response signal is generated. For example, in some embodiments, one, some, or all of the ultrasonic receiving transducers may generate an electrical response signal corresponding to the received ultrasonic energy. The method 0300 may proceed to process step 0330 where the electrical response signal is communicated to the capture module. For example, in some embodiments, the capture module of each U-BMS controller (e.g., the capture module 0240 of the controller 0180) can receive electrical response signals from one, some, or all of the connected receiving transducers (e.g., transducers 0220-0230).

[0049] The method 0300 may proceed to process step 0335, where the response signal may be modified. For example, in some embodiments, the response signal may be modified by amplifying, filtering, digitizing, cleaning, adding a signal ID, adding a timestamp, and / or structuring the electrical response signal in preparation for analysis. In some embodiments, the response signal may be modified by a capture module (e.g., capture module 0240 of controller 0180) or another module of the U-BMS controller. The method 0300 may proceed to process step 0340, where the modified response signal may be stored. In some embodiments, the modified response signal may be stored locally, for example, in a memory (e.g., memory module 0190) of the respective U-BMS controller. Alternatively or additionally, in some embodiments, the modified response signal may be stored remotely, for example, by transmitting it over the Internet to a remote processing station.

[0050] In some embodiments, the method 0300 may relate to all battery modules in all stacks of the ESS. For example, each U-BMS controller 0180, 0182 (and others, if present) may independently manage an ultrasonic interrogation sequence. In some embodiments, each U-BMS controller may be operable to perform ultrasonic interrogations of the battery modules sequentially (e.g., one at a time). Alternatively or additionally, each U-BMS controller may be operable to perform multiple ultrasonic interrogations of the battery modules (e.g., by exciting all emitter transducers simultaneously or substantially simultaneously and receiving all electrical response signals simultaneously or substantially simultaneously).

[0051] FIG. 3 illustrates a method 0350 for ultrasound-based management of battery modules of an ESS. In some embodiments, the method 0350 can be based on ultrasound interrogation of battery modules of an ESS, for example, using the method 0300 in the ESS configuration of FIG. 1. For example, the method 0350 can relate to determining an SoC and / or SoH state of each battery in a battery stack based on battery capture data instances. In some embodiments, each capture data instance can include an ultrasonic response signal received from one transducer pair coupled to one battery module. For example, a capture data instance can be based on a single instance of ultrasonic energy passing through a corresponding battery module. Alternatively or additionally, a capture data instance can be based on multiple capture data instances of ultrasonic energy passing through a corresponding battery module, and the capture data based on these multiple capture data instances can represent an average, quadratic average, or similar representation of the capture data.

[0052] The method 0350 may begin at process step 0355, where the captured data may be transmitted to the SoC / SoH module. In some embodiments, the first captured data instance corresponding to the first battery stack may be transmitted, for example, by a stack processor (e.g., stack processor 0185 of the respective U-BMS controller 0180) to the SoC / SoH module (e.g., SoC / SoH module 0250). The method 0350 may proceed to process step 0360, where the captured data may be analyzed. In some embodiments, the SoC / SoH module (e.g., SoC / SoH module 0250) may analyze the captured data, for example, by characterizing the first captured data instance corresponding to the first battery module of the first battery stack using an analysis and / or machine learning scheme (e.g., machine learning 0255).

[0053] The method 0350 may proceed to process step 0365, where an SoC value and / or an SoH value may be determined. For example, in some embodiments, the SoC / SoH module may determine an SoC value and / or an SoH value corresponding to the first battery module. The method 0350 may proceed to process step 0370, where the determined values ​​of SoC and / or SoH may be sent to a stack processor. For example, in some embodiments, the SoC / SoH module may send the SoC and / or SoH values ​​to a stack processor of each U-BMS controller. The method 0350 may proceed to determining step 0375, where process steps 0355-0370 may be repeated. For example, in some embodiments, process steps 0355-0370 may be repeated for the remaining battery modules in the battery stack until respective SoC and SoH values ​​have been submitted to a first stack processor (e.g., processor 0185) of each U-BMS controller. The same process may be performed for other stacks (eg, the second stack 0110) until an SoC value and / or an SoH value has been assigned for each battery module of each stack of the ESS.

[0054] The method 0350 may proceed to process step 0380, where balancing commands may be generated. For example, in some embodiments, the stack processor of each U-BMS controller may generate balancing commands using the SoC and / or SoH values. These balancing commands may, for example, configure the SG module (e.g., SG module 0145) to limit current to the battery module having the highest SoC value during a charge cycle and / or to limit current drawn from the battery module having the lowest SoC value during a discharge cycle. The method 0350 may return to repeating at step 0385, for example, at predetermined time intervals (e.g., intervals in the range of 0.1 minutes to 20 minutes, inclusive).

[0055] In some embodiments, the method 0350 may relate to all battery modules in all stacks of the ESS. For example, each U-BMS controller 0180, 0182 (and others, if present) may independently manage the captured data analysis to determine SoC and / or SoH values ​​sequentially or simultaneously. In some embodiments, additional SoC / SoH modules may be added (e.g., one module 0250 for each U-BMS controller) and / or parallel processing methods may be used. In some embodiments, the SoC / SoH modules may comprise cloud-based applications running on a server. Alternatively or additionally, in some embodiments, the local server or processor of each U-BMS controller (e.g., stack processor 0185 of U-BMS controller 0180, 0182) may be configured as a SoC / SoH module.

[0056] Although some of steps 0305-0340 of method 0300 and steps 0355-0385 of method 0350 have been described as being performed once, in some embodiments, multiple iterations of a particular processing step may be used before proceeding to the next decision or processing step. In addition, although steps 0305-0340 of method 0300 and steps 0355-0385 of method 0350 have been illustrated and described separately, in some embodiments, the processing steps may be combined and performed together (concurrently or sequentially). Furthermore, although FIG. 2 illustrates a particular order of steps 0305-0340 and FIG. 3 illustrates a particular order of steps 0355-0385, embodiments of the disclosed subject matter are not limited thereto. Indeed, in certain embodiments, steps may occur in a different order than those illustrated, or simultaneously with other steps. For example, although data capture step 0355 is shown as occurring prior to generating the equilibration command 0380, in some embodiments, the processing steps 0355, 380 may occur simultaneously or overlapping, for example, when ultrasound interrogation and equilibration are performed consecutively or continuously.

[0057] Ultrasound Training Model In some embodiments, the data used to train the machine learning module to assign SoC and / or SoH values ​​to each captured data sequence may be derived from charge and / or discharge cycle sequences of multiple test battery modules. For example, in some embodiments, multiple test battery modules (e.g., of the same or similar battery module type as that of the ESS system) may be evaluated to correlate ultrasonic interrogation signals and features of the ultrasonic interrogation signals with voltage, current, and / or temperature values ​​of the battery modules measured over multiple charge and discharge cycles.

[0058] To create the exemplary SoC and SoH ultrasonic signal models, a single battery was characterized by a precision battery cycler while periodic ultrasonic response signals were collected and stored. Data related to the battery's condition was collected over multiple charge / discharge cycles, and multiple charge / discharge cycles were performed over the entire life of the test battery. Throughout the development, the timing of all continuous operations was analyzed and optimized. Ultrasonic data was collected using a U-BMS controller interfaced with an ultrasonic transducer to collect ultrasonic response signals at predefined time intervals. The battery cycler collected battery temperature, voltage, and current signals from the test battery at predefined time intervals. The ultrasonic response signals, as well as the battery temperature, voltage, and current signals, were time-stamped to match which ultrasonic signals corresponded to which temperature, voltage, and current signals, respectively. The battery testing continued over the life of the battery, for example, at least 300 complete charge / discharge profiles between 0%-100% SoC, or enough cycles to include at least the span of SoH degradation. During the test, ultrasonic data was collected by the Stack U-BMS controller for 16.1 second averages of 100 tests, and SoC and SoH values ​​were determined by the SoC / SoH module for 14.4 second averages of 100 tests. Thus, new battery charge balancing data could be provided to the U-BMS controller in just over 30 s segments. Due to the cycle rate, acquisition was set for every minute.

[0059] The selected merged data was preprocessed to extract ultrasonic response signal features from each ultrasonic response signal. The feature matrix of the battery module was run through regressions with both SoC and SoH to determine which features were relevant. These regressions were then trained and tested on the entire ultrasonic response dataset to output an ultrasonic feature algorithm that maps ultrasonic signals to SoC and SoH values ​​for each individual battery. This process was repeated until the ultrasonic feature algorithm achieved the desired performance. Since only SoC was used to determine the balance, its performance was studied in more detail. The root mean square error (RMSE) and maximum error (%) of the SoC are listed in Table 1 below. The RMSE of the batteries are all below 1% for the entire range of SoC. However, the maximum error for one battery reached 7%. The described ultrasonic machine learning module and ultrasonic feature algorithm can be implemented in a SoC / SoH module (e.g., module 0250 of FIG. 1).

[0060] [Table 2]

[0061] [Table 3]

[0062] Battery Stack Charge Balancing In some embodiments, battery stack charge balancing during charging and discharging of the entire battery stack can be based, at least in part, on deriving periodic SoC and / or SoH values ​​associated with each stack battery, where the SoC and / or SoH values ​​can be derived from ultrasonic interrogation of each stack battery. Charge balancing can be initiated when the derived SoC value corresponding to one or more of the stack batteries reaches 15%. Once initiated, charge balancing can continue until the battery stack is fully charged (e.g., until the SoC value reaches 100% or nearly 100%). As described above, conventional battery stack charge balancing based on measured battery voltages was initiated when the battery stack was 80-85% charged. In contrast, the battery charge balancing method described herein demonstrates that battery stack charge balancing based on SoC and / or SoH values ​​derived from ultrasonic interrogation signals (e.g., via an ultrasonic machine learning module and ultrasonic feature algorithms) can be initiated at a battery charge level of 15% and can continue battery stack charge balancing until the charge level is 100%. Thus, the battery charge balancing method disclosed herein provides the advantage of balancing the battery stack throughout each charge and discharge cycle, including balancing charge levels between a range of 15-80% SoC during normal operation that was unavailable in conventional techniques. This increased range of charge balancing may result in increased energy storage compared to conventional management techniques. Additionally, maintaining charge balance of the battery stack during discharge between 100% charge and 15% charge may result in increased energy distribution.

[0063] Additionally, the battery charge balancing method disclosed herein highlights charge differences within the ESS, for example, by comparing actual monitored SoC values ​​with theoretical or expected charge levels of energy stored by the stack. In another experiment, a computer-based stack model was generated to evaluate a battery stack having six Nissan Leaf battery modules connected in series. The computer-based stack model was set with fixed internal resistance and SoH values ​​across all six battery modules, and the accuracy of the SoC measurement was assumed to be approximately 1% according to the model results in Table 1. The batteries were assumed to be unbalanced with a standard deviation of 5% SoC. The 5% standard deviation was selected based on observed differences in SoC with voltage in second-life ESS. The model demonstrated that through charge balancing in the center range of SoC, stack capacity increases over multiple battery cycles until it reaches its maximum limit. Specifically, it was found that the stack capacity of a single stack increased by approximately 13% over three cycles.

[0064] FIG. 4 is a graphical plot showing stack capacity in Amp-hours (A-hr) versus number of charge-discharge cycles. FIG. 4 is based on a computer-based stack model generated to evaluate a battery stack having six Nissan Leaf battery modules connected in series. The first curve, labeled "False," represents the stack at 100% charge capacity and does not apply charge balancing. As shown in FIG. 4, the first curve has a nearly constant capacity value over eight charge and discharge cycles, with an average maximum charge capacity of less than 225 A-hr. The second curve, labeled "True," represents the stack at 100% charge capacity and applies charge balancing. As shown in FIG. 4, the second curve shows a significant increase in charge capacity over the first three charge-discharge cycles, followed by a constant charge capacity of about 254 A-hr for each subsequent charge-discharge cycle.

[0065] In some embodiments, the method for battery charge balancing during a charge cycle can include the U-BMS controller instructing the BMS control panel to limit the current through the battery having the higher SoC if, during the charge cycle, the ultrasonically derived SoC value of the battery is more than 1% greater than the minimum SoC value of the other stack batteries. In some embodiments, the current can be limited, for example, by a switch to discontinue current flow and / or by a current attenuator operable to incrementally reduce the current amplitude to the battery having the higher SoC. In some embodiments, if the method for battery charge balancing is based on a subsequent ultrasonically derived SoC value of the battery having the higher SoC, and the derived SoC value is not more than 1% greater than the minimum SoC value of the other stack batteries, the U-BMS controller can instruct the BMS control panel to open a switch to allow current to flow unrestricted through the battery or incrementally increase the current amplitude to the battery by a current attenuator. In some embodiments, the method for battery charge balancing includes, if two or more ultrasound-derived SoC values ​​are more than 1% greater than the minimum SoC value of the other stacked batteries, the U-BMS controller can command the BMS control panel to limit the current through the other batteries having the higher SoC. In some embodiments, the current can be limited, for example, by a switch to discontinue current flow and / or by a current attenuator operable to incrementally reduce the current amplitude for the other batteries having the higher SoC.

[0066] In some embodiments, the method for battery charge balancing during a discharge cycle can include instructing the U-BMS controller to limit the current drawn from the battery having the lower SoC if the ultrasound derived SoC value is more than 1% lower than the minimum SoC of the other stacks during the discharge cycle. In some embodiments, the current draw can be limited, for example, by a switch to discontinue current flow and / or by a current attenuator operable to incrementally reduce the current amplitude from the battery having the lower SoC. In some embodiments, the method for battery charge balancing during a discharge cycle can further include limiting the current only for batteries with an SoC difference of more than 1% if the derived SoC value is within a 1% difference in SoC values ​​based on a subsequent ultrasound derived SoC value of the battery having the higher SoC.

[0067] Usage example Under conventional systems, it is generally faster and cheaper to retire or recycle electric vehicle batteries removed from electric vehicles rather than reusing them after their "first life" applications. However, in many cases, these batteries can be used for stationary storage, serving as backup systems for homes, data centers, hospitals, and schools, for example. The disclosed subject matter embodiments provide the ability of ultrasonic BMS technology to improve energy storage functionality (e.g., in residential solar arrays) by more accurate measurement of SoC and / or SoH, by economically identifying and selecting modules with similar SoH, by enabling more accurate BMS control of battery charging and discharging, and by balancing battery stacks of different SoH within the same system. This allows residential and industrial users to store more energy and get more energy back from their systems, while further reducing system costs by using second-life batteries.

[0068] In some embodiments, the ultrasound techniques described herein can easily replace the expensive and therefore rarely used 8-20 hour process that requires a battery cycler to determine battery SoH with a diagnostic test of shorter duration. For example, this ultrasound-based diagnostic test can be completed in a range of 10 seconds to about 45 minutes, depending on the configuration of the battery and the test equipment. This allows users to economically procure battery modules with substantially similar SoH. More accurate values ​​of SoC and SoH may also allow batteries to be safely charged and discharged to their maximum potential. Current BMS systems do not allow this functionality as they unnecessarily limit the range of charging and discharging due to uncertainties in SoC. Real-time knowledge of SoH may also allow optimal simultaneous discharge of groups of modules with different SoC and / or SoH. Furthermore, in conventional systems, discharging is stopped when the weakest stack reaches a lower limit determined by its BMS. In contrast, the more effective "dynamic balancing" of the stack provided by the disclosed technology can slow down the discharge or charge from a lower SoC stack compared to the others, so that the discharge or charge continues until the total available energy is captured. In addition, this dynamic balancing can support the addition of more capacity over time.

[0069] While the preceding examples and embodiments have been described with respect to an ultrasonic transducer coupled to a Nissan Leaf® second-life EV battery, the associated electronics for ultrasonic generation inside the battery, and for signal acquisition and analysis to determine SoC during charge and discharge cycles, are applicable to any new or used battery system that can be interrogated by ultrasound, including, but not limited to, batteries manufactured by BMW, Hyundai, Mercedes-Benz, etc. In some embodiments, a universal enclosure can be provided to accommodate batteries from different electric vehicle manufacturers, in addition to the management components of the disclosed U-ESS.

[0070] Measurement accuracy Conventional battery management systems can only measure the SoC to within 10%. In fact, conventional applications often involve simply reading the SoH from a table. Thus, the charging range over which the BMS safely charges or discharges the battery is unnecessarily limited to account for these uncertainties. With the more accurate measurements of SoC and SoH described herein, the battery can be operated closer to its true safety limits, unlocking its full chemical capacity and providing, for example, greater electric vehicle range, longer cell phone operation, etc. When second-use batteries become available in the ESS, the useful life of the battery can also be increased (e.g., 2X) due to the improved balance of the battery storage system as described herein.

[0071] [Table 4]

[0072] Computer implementation FIG. 5 illustrates a generalized example of a suitable computing environment 920 in which the described innovations may be implemented, such as aspects of the U-BMS architecture, EchOES devices, battery control panel, coordinator, etc. described above. The computing environment 920 is not intended to suggest any limitation as to scope of use or functionality, as the innovations may be implemented in a variety of general-purpose or special-purpose computing systems. For example, the computing environment 920 may be any of a variety of computing devices (e.g., desktop computers, laptop computers, server computers, tablet computers, etc.). In some embodiments, the computing environment is an integral part of the battery management system. Alternatively, in some embodiments, the computing environment is a separate system connected to the battery management system, for example, by making an operative electrical connection (e.g., wired or wireless) to the battery management system or its components.

[0073] Referring to FIG. 5, the computing environment 920 includes one or more processing units 930, 935 and memory 940, 945. In FIG. 5, this basic configuration 950 is included within the dashed line. The processing units 930, 935 execute computer-executable instructions. The processing units may be general-purpose central processing units (CPUs), processors in application specific integrated circuits (ASICs), or any other type of processor. In a multi-processing system, multiple processing units execute computer-executable instructions to increase processing power. For example, FIG. 5 shows a central processing unit 930 and a graphics processing unit or co-processing unit 935. The tangible memory 940, 945 may be volatile memory (e.g., registers, cache, RAM), non-volatile memory (e.g., ROM, EEPROM, flash memory, etc.), or some combination of the two accessible by the processing units. The memory 940, 945 stores software 925 implementing one or more innovations described herein in the form of computer-executable instructions suitable for execution by the processing unit(s).

[0074] A computing system may have additional features. For example, computing environment 920 includes storage 960, one or more input devices 970, one or more output devices 980, and one or more communication connections 990. An interconnection mechanism (not shown), such as a bus, controller, or network, interconnects the components of computing environment 920. Typically, operating system software (not shown) provides an operating environment for other software executing in computing environment 920 and coordinates the activities of the components of computing environment 920.

[0075] Tangible storage 960 may be removable or non-removable and includes magnetic disks, magnetic tapes or cassettes, CD-ROMs, DVDs, or any other medium that can be used to store information in a non-transitory manner and that can be accessed within computing environment 920. Storage 960 may store instructions for software 925 that implements one or more of the innovations described herein.

[0076] The input device(s) 970 may be a touch input device such as a keyboard, a mouse, a pen, or a trackball, a voice input device, a scanning device, or another device that provides input to the computing environment 920. The output device(s) 970 may be a display, a printer, speakers, a CD-writer, or another device that provides output from the computing environment 920.

[0077] The communication connection(s) 990 enable communication over a communication medium to another computing entity. The communication medium conveys information such as computer-executable instructions, audio or video input or output, or other data in a modulated data signal. A modulated data signal is a signal that has one or more of its characteristics set or changed in such a manner as to encode information in the signal. By way of example, and not limitation, the communication medium may use an electrical, optical, radio frequency (RF), or other carrier.

[0078] Any of the disclosed methods may be implemented as computer-executable instructions stored on one or more computer-readable storage media (e.g., one or more optical media disks, volatile memory components (such as DRAM or SRAM), or non-volatile memory components (such as flash memory or hard drives)) and executed on a computer (e.g., any commercially available computer, including a smartphone or other mobile device that includes computing hardware). The term computer-readable storage medium does not include communication connections such as signals and carrier waves. Any computer-executable instructions for implementing the disclosed techniques, as well as any data created and used during the implementation of the disclosed embodiments, may be stored on one or more computer-readable storage media. The computer-executable instructions may be a dedicated software application or part of a software application that is accessed or downloaded, for example, via a web browser or other software application (such as a remote computing application). Such software may be executed, for example, on a single local computer (e.g., any suitable commercially available computer) or in a networked environment using one or more networked computers (e.g., via the Internet, a wide area network, a local area network, a client-server network (such as a cloud computing network), or other such network).

[0079] For clarity, only some selected aspects of the software-based implementation are described. Other details well known in the art are omitted. For example, the disclosed technology is not limited to a particular computer language or program. For example, aspects of the disclosed technology can be implemented by software written in C++, Java, Perl, or any other suitable programming language. Similarly, the disclosed technology is not limited to any computer or hardware type. Specific details of suitable computers and hardware are well known and need not be described in detail in this disclosure.

[0080] It should also be appreciated that any functionality described herein may be performed, at least in part, by one or more hardware logic components instead of software. For example, and without limitation, exemplary types of hardware logic components that may be used include field programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), application specific standard products (ASSPs), systems on a chip (SoCs), complex programmable logic devices (CPLDs), etc.

[0081] Additionally, any of the software-based embodiments (e.g., including computer-executable instructions for causing a computer to perform any of the disclosed methods) can be uploaded, downloaded, or remotely accessed via suitable communication means. Such suitable communication means include, for example, the Internet, the World Wide Web, an intranet, a software application, cable (including fiber optic cable), magnetic communication, electromagnetic communication (including radio frequency, microwave, and infrared communication), electronic communication, or other such communication means. In any of the above examples and embodiments, the provision of requests (e.g., data requests), instructions (e.g., data signals), commands (e.g., control signals), or any other communication between systems, components, devices, etc. can be by generation and transmission of appropriate electrical signals via wired or wireless connections.

[0082] Further examples of the disclosed technology In view of the above implementations of the disclosed subject matter, the present application discloses additional examples in the appendices listed below. It should be noted that any feature of the appendices alone, or two or more features of the appendices taken in combination, and optionally combined with one or more features of one or more additional appendices, are also included within the scope of the disclosure of the present application.

[0083] Appendix 1. A stack of a plurality of battery modules; a plurality of ultrasonic emitter transducers, each ultrasonic emitter transducer being acoustically coupled to a respective one of the surfaces of the battery module; a plurality of ultrasonic receiving transducers, each ultrasonic receiving transducer being acoustically coupled to a respective one of the surfaces of the battery modules; one or more excitation modules in electrical communication with the plurality of ultrasonic emitter transducers; one or more capture modules electrically interfacing with the plurality of ultrasonic receiving transducers; an ultrasonic battery management system controller configured to initiate an ultrasonic interrogation sequence of the battery module;

[0084] Appendix 2. The energy storage system of any section or example of this specification, particularly Appendix 1, wherein a stack of multiple battery modules is connected in series with a power exchange module and configured such that the stack of multiple battery modules is charged or discharged during an ultrasonic interrogation sequence.

[0085] Appendix 3. The energy storage system of any one of the clauses or examples herein, particularly any one of appendices 1-2, wherein the ultrasonic emitter transducer and the ultrasonic receiving transducer are acoustically coupled to at least one battery module for a transmission mode.

[0086] Appendix 4. The energy storage system of any one of the clauses or examples herein, particularly any one of appendices 1-3, wherein the ultrasonic emitter transducer and the ultrasonic receiving transducer are acoustically coupled to at least one battery module for an echo transmission mode.

[0087] Appendix 5. The energy storage system of any of the clauses or examples herein, particularly any one of clauses 1-4, wherein the stack of multiple battery modules is connected in series with the power exchange module.

[0088] Appendix 6. a switchgear module disposed between the power exchange module and the stack of the plurality of battery modules; The energy storage system of any clause or example herein, particularly appendix 5, wherein the switchgear module is configured to manage battery charge balance during charging and discharging of the stack.

[0089] Appendix 7. The ultrasonic battery management system controller generating charge balancing commands based on the state of charge of each battery module in the stack; The energy storage system of any clause or example herein, in particular appendix 6, configured to transmit the charge balancing command to a switchgear module.

[0090] Appendix 8. The ultrasonic battery management system controller generating charge balancing commands based on the state of charge and state of health of each battery module in the stack; transmitting the charge balancing command to a switchgear module; The energy storage system of any one of the clauses or examples of this specification, particularly any one of appendices 6 to 7, configured as follows:

[0091] Appendix 9. The energy storage system according to any of the clauses or examples herein, particularly any one of Appendices 6-8, wherein at least a portion of the stacked battery modules have a state of health value of 80% or less.

[0092] Appendix 10. The energy storage system of any one of the clauses or examples herein, particularly any one of appendices 6-9, wherein the charge balance is managed over a state of charge value range of 15% to 100% during a stack charge cycle and over a state of charge value range of 100% to 15% during a stack discharge cycle.

[0093] Appendix 11. The energy storage system according to any of the clauses or examples of this specification, particularly any one of appendices 1 to 10, wherein the capture module generates capture data corresponding to each battery module.

[0094] Appendix 12. An energy storage system as described in any section or example of this specification, particularly Appendix 11, wherein the captured data corresponding to each battery module is processed by a SoC / SoH module to associate a state of charge (SoC) value with each battery module.

[0095] Appendix 13. The energy storage system of any one of the clauses or examples of this specification, particularly any one of Appendixes 11-12, wherein the captured data corresponding to each battery module is processed by an SoC / SoH module to associate a state of health (SoH) value with each battery module.

[0096] Appendix 14. The energy storage system of any one of the clauses or examples of this specification, particularly any one of Appendixes 11-13, wherein the captured data corresponding to each battery module is processed by an SoC / SoH module to associate a State of Charge (SoC) value and a State of Health (SoH) value with each battery module.

[0097] Appendix 15. acoustically coupling an ultrasonic emitter transducer and an ultrasonic receiving transducer to a battery module of a stack of a plurality of battery modules; electrically interfacing each ultrasonic emitter transducer with one or more excitation modules; electrically interfacing each ultrasonic receive transducer with one or more capture modules; initiating a battery ultrasound interrogation sequence by an ultrasonic battery management system controller; The method includes:

[0098] Appendix 16. connecting the stack in series with a power exchange module; Charging or discharging the stack during an ultrasonic interrogation sequence; Any section or example herein further including, in particular, the method of appendix 15.

[0099] Appendix 17. The method of any one of the clauses or examples herein, particularly any one of clauses 15-16, wherein at least one pair of ultrasonic emitter transducers and ultrasonic receiving transducers is coupled to one of the battery modules in a transmission mode configuration.

[0100] Appendix 18. The method of any one of the clauses or examples herein, particularly any one of clauses 15-17, wherein at least one pair of ultrasonic emitter transducers and ultrasonic receiving transducers is coupled to one of the battery modules in an echo transmission mode configuration.

[0101] Appendix 19. The method of any of the clauses or examples herein, particularly any one of clauses 15-18, wherein the ultrasonic interrogation sequence includes generating capture data corresponding to each battery module of the stack by one or more capture modules.

[0102] Appendix 20. The method of any clause or example herein, particularly appendix 19, further comprising processing the captured data generated by the SoC / SoH module to associate a state of charge value with each battery module of the stack.

[0103] Appendix 21. The method described in any clause or example of this specification, particularly any one of Appendixes 19 to 20, further comprising processing the captured data generated by the SoC / SoH module to associate a health state value with each battery module of the stack.

[0104] Appendix 22. The method of any one of the clauses or examples herein, particularly any one of Appendixes 19-21, further comprising processing the generated captured data by the SoC / SoH module to associate a state of charge value and a state of health value with each battery module of the stack.

[0105] Appendix 23. The method according to any clause or example herein, particularly any one of appendices 15 to 22, further comprising disposing a switching module between the stack and the power exchange module.

[0106] Appendix 24. The method of any section or example herein, particularly appendix 23, wherein an ultrasonic battery management system controller generates charge balancing commands based on a state of charge value associated with each battery module in the stack.

[0107] Appendix 25. Stack charge balancing is performed over a state-of-charge value range of 15% to 100% during a stack charging cycle, or Or the method of any section or example herein, particularly appendix 24, wherein charge balancing of the stack is performed over a state of charge value range of 100% to 15% during the stack discharge cycle.

[0108] Appendix 26. 1. A method for operating an energy storage system (ESS) to charge balance a stack of battery modules, comprising: (a) configuring a stack for ultrasonic interrogation of each battery module; (b) capturing ultrasonic signal data corresponding to ultrasonic energy passing through each battery module; (c) processing the ultrasonic signal data by the SoC / SoH module and assigning a state-of-charge value to each battery module; (d) generating charge balancing commands based on state of charge values ​​associated with each battery module; (e) charge balancing the stack over an assigned state of charge value range of 15% to 100% during a stack charge cycle and / or charge balancing the stack over an assigned state of charge value range of 100% to 15% during a stack discharge cycle; The method includes:

[0109] Appendix 27. (f) The method of any section or example herein, particularly Appendix 26, further comprising repeating (a) to (e).

[0110] Appendix 28. 1. A method for charge balancing in an energy storage system including a stack of multiple battery modules, comprising: (a) During the stack charging cycle, Measuring a state of charge (SoC) of each battery module in the stack; generating one or more control signals to cause limiting of current through a first module of the battery modules in response to a measured SoC for the first module being more than 1% above a first threshold; re-measuring the SoC for each battery module in the stack; generating one or more control signals that cause removal of the limit on current through a first module of the battery modules in response to the re-measured (SoC) for the first module being within 1% of a first threshold; The method includes:

[0111] Appendix 29. 1. A method for charge balancing in an energy storage system including a stack of multiple battery modules, comprising: (b) During the discharge cycle of the stack, Measuring the state of charge (SoC) of each battery module in the stack; generating one or more control signals to limit current drawn from a first one of the battery modules in response to the measured SoC for the first one of the battery modules being more than 1% less than a second threshold; re-measuring the SoC for each battery module in the stack; in response to the re-measured SoC for a first one of the battery modules being within 1% of a second threshold, generating one or more control signals that cause removal of the limit on current drawn from the first module; The method includes:

[0112] Appendix 30. The method of any section or example herein, particularly any one of Appendixes 28-29, wherein the first threshold, the second threshold, or both, include a minimum determined SoC for the remaining battery modules in the stack.

[0113] Appendix 31. The method of any clause or example herein, particularly any one of appendices 28 to 30, wherein the current through the first module, the current drawn from the first module, or both, is limited by a switch that interrupts the flow of current or by a current attenuator operable to incrementally reduce the current amplitude to the first module.

[0114] Appendix 32. The method of any one of the clauses or examples herein, particularly any one of appendices 28-31, wherein the SoC for one, some, or all of the battery modules is at least 15% during a charge and / or discharge cycle.

[0115] Appendix 33. The method of any one of the clauses or examples herein, particularly any one of clauses 28-32, wherein during a charge and / or discharge cycle, the SoC for one, some, or all of the battery modules is within the range of 15-80%, inclusive.

[0116] Appendix 34. The method of any one of the clauses or examples herein, particularly any one of appendices 28-33, wherein the SoC for one, some, or all of the battery modules is at least 80% during a charge and / or discharge cycle.

[0117] Appendix 35. Measuring the SoC and / or re-measuring the SoC ultrasonically interrogating the battery module to generate one or more ultrasonic signals; determining a SoC of each battery module based at least in part on the one or more ultrasonic signals; The method of any one of the clauses or examples herein, particularly any one of clauses 28 to 34, including:

[0118] Appendix 36. 1. An ultrasonic based battery management system (U-BMS), comprising: one or more processors; A computer-readable storage medium storing computer-readable instructions that, when executed by the one or more processors, cause the one or more processors to execute a method according to any of the sections or examples of this specification, particularly any one of appendices 15 to 35; An ultrasonic based battery management system including:

[0119] Appendix 37. A stack of a plurality of battery modules; The ultrasound-based battery management system of appended claim 36; 23. An energy storage system comprising:

[0120] Appendix 38. The energy storage system of any of the sections or examples herein, particularly Appendix 37, wherein each battery module comprises a second-use lithium ion battery module.

[0121] conclusion Although the batteries, components, and configurations are shown in the drawings and described in detail herein, the embodiments of the disclosed subject matter are not limited thereto. Indeed, those skilled in the art will readily appreciate that different batteries, components, or configurations may be selected and / or added to provide the same effect. In actual implementations, the embodiments may include additional components or other variations beyond those shown. Thus, the embodiments of the disclosed subject matter are not limited to the particular batteries, components, and configurations specifically shown and described herein.

[0122] Any of the features illustrated or described in this specification and drawings, for example, with respect to Figures 1-5 and Appendices 1-38, can be combined with any other features illustrated or described in this specification and drawings, for example, with respect to Figures 1-5 and Appendices 1-38, to provide systems, devices, methods, and embodiments not otherwise illustrated or specifically described herein. All features described herein are independent of one another and, unless structurally impossible, can be used in combination with any other feature described herein.

[0123] In view of the many possible embodiments to which the principles of the disclosed technology may be applied, it should be recognized that the illustrated embodiments are examples only and should not be construed as limiting the scope of the disclosed technology. Rather, the scope is defined by the following claims. The inventors therefore claim all that comes within the scope and spirit of these claims.

Claims

1. A stack of battery modules; a plurality of ultrasonic emitter transducers, each ultrasonic emitter transducer being acoustically coupled to a surface of a respective one of the battery modules; a plurality of ultrasonic receiving transducers, each ultrasonic receiving transducer being acoustically coupled to a surface of a respective one of the battery modules; one or more excitation modules in electrical communication with the plurality of ultrasonic emitter transducers; one or more capture modules electrically interfacing with the plurality of ultrasonic receiving transducers; an ultrasonic battery management system controller configured to initiate an ultrasonic interrogation sequence of the battery module; 23. An energy storage system comprising:

2. The stack of battery modules is connected in series with a power exchange module; 2. The energy storage system of claim 1, wherein the stack of battery modules is configured to be charged or discharged during the ultrasonic interrogation sequence of the battery modules.

3. 2. The energy storage system of claim 1, wherein the ultrasonic emitter transducer and the ultrasonic receiving transducer are acoustically coupled to at least one of the battery modules for a transmission mode.

4. 2. The energy storage system of claim 1, wherein the ultrasonic emitter transducer and the ultrasonic receiving transducer are acoustically coupled to at least one of the battery modules for an echo transmission mode.

5. The stack of battery modules is connected in series with a power exchange module; the energy storage system further includes a switchgear module disposed between the power exchange module and the stack of battery modules; 10. The energy storage system of claim 1, wherein the switchgear module is configured to manage battery charge balance during charging and discharging of the stack of battery modules.

6. The ultrasonic battery management system controller includes: generating a charge balancing command based on a state of charge (SoC), a state of health (SoH), or both SoC and SoH of each battery module in the stack of battery modules; The energy storage system of claim 5 , configured to transmit the charge balancing commands to a switchgear module.

7. 6. The energy storage system of claim 5, wherein at least a portion of the stack of battery modules has a State of Health (SoH) value of 80% or less.

8. 6. The energy storage system of claim 5, wherein the battery charge balance is managed over a State of Charge (SoC) value range of 15% to 100% (inclusive) during a charge cycle of the stack of battery modules and is managed over a State of Charge (SoC) value range of 100% to 15% (inclusive) during a discharge cycle of the stack of battery modules.

9. One or more of the capture modules generate capture data corresponding to each battery module; 2. The energy storage system of claim 1, wherein the captured data corresponding to each battery module is processed by a SoC / SoH module to associate a State of Charge (SoC) value, a State of Health (SoH) value, or both an SoH value and an SoH value with each battery module.

10. acoustically coupling an ultrasonic emitter transducer and an ultrasonic receiving transducer to a battery module in the stack of battery modules; electrically interfacing each ultrasound emitter transducer with one or more excitation modules; electrically interfacing each ultrasonic receive transducer with one or more capture modules; initiating a battery ultrasound interrogation sequence by an ultrasonic battery management system controller; The method includes:

11. Connecting the stack of battery modules in series with a power exchange module. charging or discharging the stack of battery modules during an ultrasonic interrogation sequence of the battery modules; The method of claim 10 further comprising:

12. The method of claim 10 , wherein at least one pair of the ultrasonic emitter transducer and the ultrasonic receiving transducer are coupled to one of the battery modules in a transmission mode configuration.

13. The method of claim 10 , wherein at least one pair of the ultrasonic emitter transducer and the ultrasonic receiving transducer are coupled to one of the battery modules in an echo transmit mode configuration.

14. The method of claim 10, wherein the ultrasonic interrogation sequence of the battery modules includes generating capture data corresponding to each battery module in the stack of battery modules by the one or more capture modules.

15. 15. The method of claim 14, further comprising processing the generated captured data by a SoC / SoH module to associate a State of Charge (SoC) value with each battery module in the stack of battery modules.

16. 15. The method of claim 14, further comprising processing the generated captured data by a SoC / SoH module to associate a State of Health (SoH) value with each battery module in the stack of battery modules.

17. 15. The method of claim 14, further comprising processing the generated captured data by a SoC / SoH module to associate a State of Charge (SoC) value and a State of Health (SoH) value with each battery module in the stack of battery modules.

18. The method of claim 10, further comprising disposing a switching module between the stack of battery modules and the power exchange module.

19. 20. The method of claim 18, further comprising generating, by an ultrasonic battery management system controller, charge balancing commands based on a state of charge (SoC) value associated with each battery module in the stack of battery modules.

20. Charge balancing of the stack of battery modules is performed over a state of charge (SoC) value range of 15% to 100% during a charge cycle of the stack of battery modules; or 20. The method of claim 19, wherein charge balancing of the stack of battery modules is performed over a State of Charge (SoC) value range of 100% to 15% during a discharge cycle of the stack of battery modules.

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