Auxiliary device for monitoring electric battery systems

Abstract

The present disclosure relates to an auxiliary device for monitoring modules and / or packs of an electric battery system. The auxiliary device provides module-level and / or pack-level measurements and may be flexibly placed anywhere within the electric battery monitoring system.

Description

[Background technology]

[0001] Battery systems comprising multiple battery cells are used in a wide range of modern power applications. For example, they are used to power electric vehicles, they are used in industrial power applications, transportation, and commercial applications such as powering modern electronic devices. Given the relatively high power requirements of such applications, battery systems often comprise multiple battery cells coupled together to achieve the required power output. The battery cells may be coupled together to form a battery pack, and the battery system may comprise one or more battery packs.

[0002] It is common to connect a battery system to a battery management system (BMS) configured to ensure that the battery system operates within its safe operating area. The safe operating area is defined as the voltage and current conditions and environmental conditions within which the battery system is expected to operate without self-damage. Interested readers are referred to the following Wikipedia website for further details: https: / / en.wikipedia.org / wiki / Battery_management_system.

[0003] In one particular known application, performance characteristics of battery cells in a battery system may be monitored to identify potential faulty operation of the battery cells in the battery system before a catastrophic failure occurs. Such measurements are made using devices called cell monitoring devices (CMDs). CMDs provide cell-level measurements such that individual measurements are made on individual cells and the information obtained is about the individual cells. Summary of the Invention

[0004] In some cases, it may be beneficial to receive information on the module or pack level, rather than on the level of individual cells. Currently, cell-level measurements from various CMDs are evaluated to obtain such information. Pack and module level measurements help provide more information to the monitoring system, and anomalies such as, for example, thermal runaway, may be more easily detected. Thus, auxiliary devices are presented herein. The auxiliary devices may be used to provide pack-level and / or module-level and / or battery system-level measurements in a manner independent of the CMDs.

[0005] Exemplary embodiments presented herein include a method in an auxiliary device for monitoring modules and / or packs of an electronic battery system. The electronic battery system comprises at least one pack, each pack comprises at least one module, and each module comprises a number of battery cells. Each battery cell is monitored via a cell monitoring device (CMD) that provides cell-level measurements.

[0006] The method includes obtaining module-level and / or pack-level measurements associated with at least one module and / or at least one pack, respectively, with at least one sensor included in the auxiliary device, the cell-level measurements being separate from the module-level and pack-level measurements.

[0007] The method further includes transmitting the module-level and / or pack-level measurements via the short-range wireless antennas of the auxiliary devices to a centralized control unit via a short-range wireless communication bus. The centralized control unit is configured to control operation of the electric battery system. The short-range wireless communication bus is utilized by each CMD in transmitting the cell-level measurements to the centralized control unit via the CMD's respective short-range wireless antennas.

[0008] The exemplary embodiments presented herein also include an auxiliary device for monitoring the modules and / or packs of the electric battery system. The exemplary embodiments further comprise a machine-readable storage medium storing a set of instructions executable by one or more processors of the auxiliary device to monitor the modules and / or packs. The auxiliary device and the set of instructions are configured to perform the methods described above and herein.

[0009] The foregoing will be explained in more detail in the following more particular description of exemplary embodiments, as illustrated in the accompanying drawings, in which reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating example embodiments. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is an illustrative diagram of a battery monitoring system. [Diagram 2] FIG. 1 is an illustrative diagram of a battery monitoring system featuring a master / slave communication configuration. [Diagram 3] 1 is an illustrative example of a battery monitoring system featuring an auxiliary device according to some of the example embodiments presented herein. [Figure 4] 1 is an illustrative example of an RF-based power supply auxiliary device according to some of the example embodiments presented herein. [Diagram 5] 1 is an illustrative example of an auxiliary device powered by a battery module according to some of the example embodiments presented herein. [Figure 6A] 1 is an illustrative example of an auxiliary device powered by an external source and a fan operation control process according to some of the example embodiments presented herein. [Figure 6B] 1 is an illustrative example of a number of auxiliary devices within a thermal management system. [Figure 7A]FIG. 2 is a schematic diagram of a fault indication control process according to some of the example embodiments presented herein. [Figure 7B] 4 is a schematic diagram of a commutation switch control process according to some of the example embodiments presented herein. [Figure 7C] 1 is a schematic diagram of a termination control process according to some of the example embodiments presented herein. [Figure 8] 1 is an illustrative example of EM filtering according to some of the example embodiments presented herein. [Figure 9] FIG. 3 is a schematic diagram of an energy battery storage system featuring the battery monitoring system of FIG. 2. [Figure 10] FIG. 4 is a schematic diagram of an energy battery storage system featuring the battery monitoring system of FIG. 3 according to some of the example embodiments presented herein. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Reference will now be made in detail to the exemplary embodiments, examples of which are illustrated in the accompanying drawings. The following description refers to the accompanying drawings, in which the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The implementations described in the following description of the exemplary embodiments do not represent all implementations consistent with the present invention. Instead, they are merely examples of apparatus and methods consistent with aspects related to the present invention as set forth in the appended claims.

[0012] A battery system typically comprises multiple cells wired in a configuration that provides the desired battery system voltage and capacity, along with additional components necessary for the safe operation of the cells and the transfer of energy to and from the cells. The cell is the basic unit of any battery system. The defining characteristic of a cell is its electrochemical characteristics. For a particular cell chemistry, there is a minimum, nominal, and maximum voltage that is determined by the electrochemistry of the system, not the configuration of the system. The voltage cannot be changed except by changing the electrochemical state of the cell. Cells may be wired in parallel to increase the overall capacity, but these parallel cells still have the same voltage characteristics as determined by the electrochemistry and can therefore simply be considered as a larger single cell from a cell monitoring perspective.

[0013] Cells can also be wired in series. A series stack of cells has a voltage determined primarily by the stack configuration. The voltage will be the sum of the cell voltages. The stack voltage can be changed by adding or removing cells without changing their electrochemical state. Typically, a stack of cells is charged and discharged, changing their electrochemical state in tandem. Each cell must be monitored to ensure it is within a safe operating area. This is the job of the Cell Monitoring Device (CMD). The CMD provides cell-level measurements such that individual measurements are made on each individual cell and the information obtained is about the individual cell.

[0014] A battery pack consists of multiple cells in series. A battery pack provides the full voltage of the battery system. Multiple battery packs can be wired in parallel to increase the capacity of the battery system, but not in series. Cells can be grouped into modules. The defining characteristic of a module is its physical configuration, e.g., the number and connectivity between several cells. A module can consist of any number of cells. A module can consist of two or more cells, or an entire pack. If there is only a single pack in the battery system, a module can encompass the entire battery system.

[0015] More often, however, a pack is configured as multiple modules, with each module configured from multiple cells in series. The multiple modules are then wired in series, or in parallel and series. The voltage of the battery system, the modules wired in parallel, can be considered a pack. The modules have a defined size, shape, and are typically packaged in some type of enclosure.

[0016] The module configuration is dictated by the physical requirements of the battery pack. In many cases, modules are configured to have a low enough voltage that they can handle without the presence of a shock hazard. In many cases, modules are configured for a number of cells that matches the number of voltage sense inputs on the cell monitoring device. A very common example is a 12 cell monitoring device. The module then consists of 12 cells and connections to the cell monitoring device. In many battery packs, the CMD attributes define the module configuration, and the battery pack is then built from multiple such modules.

[0017] FIG. 1 illustrates a known prior art system. The battery system of FIG. 1 includes three battery modules 170, each including eight battery cells (C1-C8) 160. Each battery cell C1-C8 in each battery module 170 is hardwired to a respective CMD 180. The location of each cell C1-C8 in the battery module 170 may be mapped during assembly of the battery module 170. In use, the CMD 180 may receive measurement data from each of the cells C1-C8 and determine the source of the received measurement data based on predefined cell mapping information. The CMDs 180 illustrated in FIG. 1 are connected in a star topology. Alternatively, each CMD 180 may be connected to the BMS via a serial daisy-chain connection. The star topology is advantageous because there is no communication hierarchy imposed on the BMS 150, and instead communication with each CMD 180 is by direct wired connection without the use of any proxy.

[0018] A drawback of the system illustrated in FIG. 1 is that a particular measurement can or only needs to be made at one location in a pack or module. As an example, the current through a series of strings of cells does not need to be measured at every cell because the current should be the same for all cells. Thus, the current needs to be measured only once for each series of strings. A CMD may be adapted to measure the current in one or more cells that it measures, but this places a limitation on that CMD since it defines the location of the current measurement. For example, it may be desirable to measure the current at another location in the pack, at the point where the power enters the battery system or pack. A long sensor wire could be run to a sensor located remotely from the CMD, but this is also undesirable due to noise pickup. Adapting the CMDs to make these pack-level measurements also means that one of the CMDs will be different from the rest, or if all CMDs are adapted, many CMDs will not have sensor inputs connected, resulting in waste on the other CMDs.

[0019] FIG. 2 illustrates another known example of a battery system 207. The system of FIG. 2 features a single battery pack 208 with eight battery modules 201. Each battery module includes 12 cells, each monitored by a respective CMD 206, each CMD including 12 voltage measurements (V), one for each cell, and one or more temperature measurements (T). Each of the CMDs communicates with a central control unit 209 or battery management system (BMS) via a separate SPI or CAN communication bus 203. The BMS controls the communications of each CMD. As illustrated in FIG. 2, each CMD may include additional hard-wired sensors 205 that communicate via the CMD.

[0020] 2 illustrates the use of additional sensors 205 or 210, such sensors are hard-wired to the CMD 201 or controller 209 and therefore do not allow for much flexibility with respect to placement in or on the battery system. Furthermore, the use of a controller / CMD configuration limits the availability to add additional sensors or monitoring devices to an existing system, for example, after the initial implementation of the monitoring system. A further disadvantage of the system of FIG. 2 is that the additional sensors cannot use the same communication means without significant system redesign.

[0021] Thus, the disclosed embodiments relate to an auxiliary device for monitoring a module, pack, and / or electric battery system. The auxiliary device provides module-level, pack-level, and / or system measurements and may be flexibly located anywhere in the electric battery system. FIG. 3 illustrates an electric battery system featuring an auxiliary device 315 according to some of the exemplary embodiments presented herein. The electric battery system 316 of FIG. 3 includes a single battery pack 317 featuring eight battery modules 301. Each battery module 301 features twelve battery cells 305. Each battery cell 305 is monitored by a respective CMD 307 that provides cell-level measurements. Each CMD 307 is configured to communicate with a central controller or BMS via a short-range wireless communication bus 309. To enable such communication, each CMD includes a respective short-range wireless antenna 311.

[0022] According to some of the exemplary embodiments, an auxiliary device may be disposed on or within the electric battery system to obtain module-level or pack-level measurements. In the example provided in FIG. 3, an auxiliary device A is located within the housing of each battery module 301. Such an arrangement allows the auxiliary device to obtain module-level measurements of the battery system. It should be understood that the auxiliary device may be disposed near multiple modules such that a single auxiliary device may obtain module-level measurements on multiple modules. In such an exemplary embodiment, the auxiliary device may be located, for example, between two adjacent modules.

[0023] In the example provided by FIG. 3, auxiliary device A is also provided in a position that allows pack level measurements to be obtained. Specifically, auxiliary devices A 320, 321, and 322 provide an example of an auxiliary device featuring a pack voltage measurement sensor, a battery system isolation resistance measurement sensor, and a pack current measurement sensor, respectively. A further example of an auxiliary device placement for obtaining pack level measurements is provided in 323, where the auxiliary device is placed in close proximity to a pack switch, commonly referred to as a contactor, and associated drive and sense circuitry. Auxiliary device A 324 may be configured to measure the output voltage of the battery pack. As a further example, auxiliary device A may be placed in close proximity to a main power connection to the battery system (traction connector) 325. The power connection includes a safety interlock switch that indicates the presence or absence of a mating connector. Auxiliary device A on 325 can report the state of this safety interlock switch.

[0024] Data from any or all of these sensors that may be provided to the auxiliary devices is valuable to the battery system controller. Therefore, it may be beneficial to provide current sensors in the auxiliary devices and place them on a separate short-range wireless bus antenna communication network 309. This provides a flat hierarchical relationship between each of the devices. This simplifies the flow of data around the vehicle system and may facilitate improved performance. For example, battery cell state of charge algorithms often need to know if the system is charging. Having charger current data on the battery system communication network makes this easier.

[0025] Furthermore, having a current sensor in the form of an auxiliary device also allows the current measurement to be synchronized with other measurements in the system. For example, to calculate cell characteristics such as internal resistance, voltage and current measurements need to be made at approximately the same time. Because the auxiliary device is on the same communication network as the voltage measurement (which is typically made on the CMD, but sometimes on yet another auxiliary device), the samples can be synchronized.

[0026] A close-up 315 of auxiliary device A provides one example of features that may be included on the device. In the example provided in FIG. 3, auxiliary device A may include a temperature sensor and a voltage sensor. It should be understood that the auxiliary device may include any number or type of sensors used in monitoring an electric battery system. Examples of such sensors may be temperature, voltage, current, pressure, shock, gas, leakage current, security / tamper detection, interlock status, fluid flow, gas flow, actuator position, fan / motor speed detectors, and / or other environmental sensors.

[0027] The auxiliary device A may also comprise a controller or processing unit that may be used to provide pre-processing to any acquired measurements and to determine a control process based on any acquired measurements. According to some of the exemplary embodiments, the auxiliary device may have programmable processing capabilities that allow the control functions of the pack to be distributed between the central controller and the modules. This means that the modules can continue to operate even if the central controller is inactive. According to some of the exemplary embodiments, the auxiliary device may implement two operating modes: active and sleep. In active mode, the auxiliary device reports its measurements to the system controller periodically (e.g., once per second). In sleep mode, the auxiliary device consumes minimal power and only occasionally makes measurements. These measurements are processed and / or stored locally, after which the auxiliary device again enters sleep mode.

[0028] According to some of the example embodiments, the auxiliary device monitors the presence of a manual service disconnect, an external high voltage connector, or a safety interlock external to the battery system and transmits the status to the central controller.

[0029] The auxiliary device 315 may further comprise a radio frequency antenna 313 that is used to communicate with the central controller 318, i.e., BMS, via the short range wireless communication bus 309 in the same manner and using the same protocols as the individual CMDs. The radio frequency antenna 313 may be used in transmitting acquired module-level, pack-level, and / or system-level measurements to the centralized control unit. The transmitted measurements may further include a unique identifier associated with the auxiliary device that is used by the centralized controller in identifying the auxiliary device with which to communicate. The auxiliary device may also include a unique identifier of the CMD or other auxiliary device in the same module such that the auxiliary device may make control decisions based on a subset of the CMD measurements. The radio frequency antenna 313 may also be configured to receive measurements and / or operation commands from the centralized control unit.

[0030] According to some of the example embodiments, the auxiliary device may also include a memory unit that may accumulate a history of past measurements made by the auxiliary device. The stored history may be used by the auxiliary device in determining control processes within the battery system. It should be understood that the auxiliary device may also be configured to perform measurement and / or operation tasks autonomously.

[0031] It should be understood that the placement of the auxiliary devices in FIG. 3 is provided only as an example. Any number of auxiliary devices may be used at any location along / adjacent to the short-range wireless communication bus without the use of additional wiring. The use of the short-range wireless communication bus allows for auxiliary devices that may be pre-existing to be added to the electric battery system, and thus the battery monitoring system may be adapted according to the needs that may arise. Such adaptation may be provided without requiring extensive modifications or the use of new communication protocols. It should be understood that the use of auxiliary devices allows the device and the CMD to be placed on the same communication bus, and thus may be synchronized by communication. Furthermore, the short-range wireless bus may be extended beyond the battery system to include additional systems such as infotainment, motor drive, etc.

[0032] According to some of the exemplary embodiments, an auxiliary device can derive its power from an electric battery system without requiring redesign to the existing battery system. Figure 4 is an example of an auxiliary device 402 contained within a pack housing 401 deriving its power from a near field communication bus 407 using, for example, a bias tee mechanism 403. The bias tee is a standard RF device with three ports, an RF port, a DC port, and an RF and DC port. The bias tee separates the RF and DC energy on the RF and DC ports, provides the RF energy on the RF port and thus to the bus antenna, and provides the DC energy to the DC port, where it is used to power the auxiliary device via a power conditioning circuit 404.

[0033] FIG. 4 also shows the use of a balun 405. This allows RF signals with excess DC power to be distributed from the central controller 408 over an unbalanced connection, for example on a coaxial cable. The unbalanced connection is then converted to a balanced short-range wireless bus antenna signal. In general, the short-range wireless bus can be balanced or unbalanced, and a balun may not be required. However, if a balun is present, this is an appropriate location for the auxiliary device, as it facilitates the use of a bias tee to power the auxiliary device.

[0034] In Figure 4, DC power can be provided to the auxiliary devices without additional connections. Note that CMD 406 cannot be powered using a bias tee because this would require all CMDs to make an electrical connection (as opposed to a short-range wireless connection), thus breaking the isolation requirements or forcing the additional complexity of an isolated DC:DC converter. Because the auxiliary devices do not need to be connected to any cells, they can be at any potential, including that of the bus antenna.

[0035] According to some of the example embodiments, the auxiliary device may draw its power from a battery pack or module that it is monitoring, as illustrated in Figure 5. In the example shown in Figure 5, the auxiliary device 501 is connected directly to the supply line of the battery pack 502.

[0036] According to some of the example embodiments, the auxiliary device may derive its power from an external source within the electric battery system. In the example provided by Fig. 6A, the auxiliary device 601 is powered by a 12V external power supply that is also used to power a fan 604 within the battery system. Specifically, the 12V external power supply may be configured to power a fan power supply 603 and a controller 602 within the auxiliary device 601.

[0037] According to some of the example embodiments, the auxiliary devices may be configured to control the process based on module-level, pack-level, and / or system-level measurements or instructions obtained from a central controller.

[0038] According to some of the example embodiments, the control process may be to control the operation of a fan or cooling fluid valve, or any other thermal management system of the electric battery system. For example, the auxiliary device may include a temperature sensor. Upon analyzing the acquired module-level and / or pack-level measurements and / or system-level measurements and detecting a high temperature or a command from the central controller, the auxiliary device may be configured to open a fluid valve or increase the speed of the fan 604 to reduce the temperature, as shown in FIG. 6A.

[0039] FIG. 6A shows a single fan that may be used to control the temperature of the battery pack. The fan may instead be some other mechanism for controlling the temperature of the pack. For example, it may be a valve that controls the flow of gaseous coolant around the battery pack. It may be a valve that controls the flow of liquid coolant around the battery pack. The example of FIG. 6A emphasizes that these devices may communicate over a network and may be auxiliary devices as described herein.

[0040] The controlled device can take various forms within a battery thermal management system and perform additional functions. It is a known requirement to maintain all battery cells in a battery pack as close to the same temperature as possible. Hot cells have a shorter life span and cells at different temperatures have different self-discharge characteristics, resulting in an unbalanced battery pack (cells at different states of charge).

[0041] FIG. 6B illustrates a further example utilizing auxiliary devices for different purposes within the thermal management system. The battery pack of FIG. 6B includes 48 individual battery cells, each of which is monitored via its respective CMD. The thermal management system consists of six coolant loops (only two are shown in FIG. 6B, the other four are identical and their positions are such that the coolant loops are equally spread between the battery cells for cooling purposes) configured to lower the temperature battery cells in their path as the coolant enters the loop through the valves. Valves 312 are controlled via auxiliary device "B" such that when valves 312 are opened, the coolant is transferred into tubes 314 surrounding the various cells in the battery pack. Each auxiliary device (auxiliary device "B") is configured to control the operation of valves 312 based on information provided by the central controller and / or measurements taken by itself or other auxiliary devices in the system. In the example provided in FIG. 6B, an auxiliary device (auxiliary device "A") is provided to monitor each grasshopper module 310A-310D. Thus, information gathered by auxiliary device “A” may be used by auxiliary device “B” in controlling value 312 .

[0042] The way in which the thermal management system is divided may not match the way in which the battery modules are divided. The use of auxiliary devices allows any grouping of cells to be controlled independent of the grouping or division of cells for cell monitoring purposes. The auxiliary devices are on the same communication network as the cell monitoring device(s) and therefore can receive data regarding temperature from each cell.

[0043] A further example of the control process is illustrated in Fig. 7A. Fig. 7A illustrates a configuration of four battery packs 701 arranged in the form of parallel cell strings. An auxiliary device A is disposed in each cell string and controls an electrically operated disconnect or fuse 702, such as a pyrofuse. Based on the obtained pack level measurements, the auxiliary device may detect a fault in the battery pack. Upon such detection, or in response to a command from a central controller, the auxiliary device may activate a pyrofuse 703, thereby removing the affected cell string from operation. Upon removal of the cell string, the electric battery system continues to function, but the battery system has a reduced capacity.

[0044] According to some exemplary embodiments, the control process may control a safety disconnect, such as a contactor or solid state relay. For example, upon detecting an anomaly in the acquired module-level, pack-level and / or system-level measurements, or in commands from a central controller, the auxiliary device may activate a safety disconnect, thereby shutting down operation of the battery system to prevent a hazardous event.

[0045] According to some of the exemplary embodiments, the control process may be controlling a commutation switch, such as an H-bridge, as illustrated in FIG. 7B. The commutation switch is used to control the manner in which the switched cells are connected into the battery system. Cells can typically be disconnected from the stack (open circuit), bypassed (short circuit), or connected in either polarity. This has applications in motor control, where reversing the polarity can reverse the direction of the connected motor. This also applies to pulse width modulation systems, or modular multilevel converter systems, in either case, arbitrary waveforms can be generated by rapidly switching cells in and out. Auxiliary devices provide a means of integrating this switching into a battery system. FIG. 7B shows such an auxiliary device 701b featuring a bus antenna 704b, with an H-bridge 703b controlled by process 702b.

[0046] According to some of the exemplary embodiments, the modules are included in the housing and the auxiliary device is located at the boundary of the housing. FIG. 7C illustrates the contents of a battery module housing 700c featuring a number of battery cells 702c, each battery cell with its own CMD. The auxiliary device 703c includes any number of sensors 706c, an internal controller 705c, and a radio receiver 704c. The auxiliary device 703c may be placed at the other end of the short-range wireless communication bus 708c from the central controller 701c and may be used to electrically terminate the bus. The short-range wireless bus is required to have a termination resistor with a value that depends on the characteristic impedance of the bus antenna. In this case, the auxiliary device does not couple to the short-range wireless bus using a short-range wireless coupling, but instead connects directly to the bus. The radio receiver 704c included in the auxiliary device 703c provides a termination impedance of typically 50 Ω. The short-range wireless protocol used remains the same and the auxiliary device continues to use the same short-range wireless bus as the CMD.

[0047] According to some of the exemplary embodiments where the auxiliary device is located at the boundary of the housing of the module and the auxiliary device takes its power through a bias-tee mechanism, the auxiliary device may be further configured to filter electromagnetic (EM) interference from entering or leaving the housing, as illustrated in FIG. 8. As illustrated in FIG. 8, EM filtering may create a "clean box" within the battery pack 802. Electromagnetic interference picked up outside the housing 803 is conducted to the clean box on the short-range wireless communication bus 804. The auxiliary device 805 may filter EM noise from the bus antenna by using an electrical filter as part of the bias-tee device placed alongside the short-range wireless antenna, advantageously positioned where the connection is made through the housing. The noise energy is then directed onto the housing rather than being allowed to enter the housing, thereby improving cell-level measurements that may be obtained by the CMD located within the battery pack.

[0048] According to some of the example embodiments, an auxiliary device may be utilized in obtaining additional measurements associated with the environment external to the battery system enclosure. For example, an auxiliary device may be used to measure the temperature of the environment surrounding the battery pack enclosure, rather than the temperature resulting from the operation of the battery cells within the battery pack.

[0049] According to some of the exemplary embodiments, the auxiliary device may be further configured to provide measurements associated with at least one auxiliary system, the auxiliary system being separate and distinct from the electric battery system. According to some of the exemplary embodiments, the auxiliary system is in a battery electric vehicle. For example, the auxiliary device may be configured to make measurements of vehicle components proximate to the battery pack. For example, a coolant pump may be installed outside the electric battery system and supply coolant to other vehicle systems, such as air conditioning. For optimized operation of the battery system, it may be important for the battery system to make measurements on the coolant pump. The auxiliary device may then send such measurements to a centralized controller.

[0050] As another example, the battery system may need to know and be able to control the status of the vehicle's on-board charger. Although the on-board charger is typically not part of the battery system, its operation is closely related to the operation of the battery system, so it is desirable to connect the sensing and control of the on-board charger to the battery system controller via the same short-range wireless communication bus. Thus, the auxiliary device may be configured to obtain measurements of the vehicle's on-board charger and transmit such measurements to the centralized controller.

[0051] As an additional example, the battery system may need to know and be able to control the state of a vehicle electrical inverter that converts the DC battery voltage into an AC voltage suitable for driving a traction motor. Again, the inverter is typically not part of the battery system, but its operation is closely related to the operation of the battery system. Thus, the auxiliary device may also be configured to obtain inverter measurements, as long as the inverter is installed on or near the short-range wireless communication bus.

[0052] According to some embodiments, the auxiliary system may be a battery energy storage system. Figure 9 illustrates a known battery storage system featuring the battery monitoring system of Figure 2. As illustrated in Figure 9, the storage system consists of multiple independent systems such as an HVAC system, a security system, an ancillary service, and a BMS. Many of these separate systems may use separate communication protocols or channels 901, 902, 903, 904, 905. Thus, such a system would not facilitate easy provision of new sensors used to monitor the various separate systems.

[0053] Figure 10 illustrates the storage system of Figure 9 featuring the battery monitoring system of Figure 3. In the example provided by Figure 3, the storage cabinets and independent monitoring systems are all configured to communicate over a short-range wireless communication bus 1001. Furthermore, each system is configured to have a respective short-range wireless antenna for communicating over the short-range wireless communication bus. Such a configuration eliminates the strict hierarchical constraints associated with the system of Figure 9. The use of auxiliary devices allows for monitoring of various systems over a single communication bus.

[0054] The auxiliary device(s) A of FIG. 10 may also assist in data collection. By connecting all sensors to a common bus, data is collected in one place, rather than being distributed across multiple systems. Furthermore, the use of a short-range wireless communication bus allows the auxiliary device to be implemented in a plug-and-play manner. Specifically, the auxiliary device may be added anywhere in the system of FIG. 10 as long as the device has access to the short-range wireless communication bus. Thus, the auxiliary device does not need to be included at the manufacturing stage, but may instead be included in an existing system. It should be understood that as long as the battery monitoring system and the auxiliary system have access to the short-range wireless communication bus, the auxiliary device may be placed anywhere along the communication bus to monitor any aspect of the battery monitoring system and / or the auxiliary system.

[0055] The description of the exemplary embodiments provided herein is presented for the purpose of illustration. The description is not intended to be exhaustive or to limit the exemplary embodiments to the precise form disclosed, and modifications and variations are possible in light of the above teachings or may be acquired from the practice of various alternatives to the provided embodiments. The examples discussed herein are selected and described in order to explain the principles and properties of the various exemplary embodiments and their practical applications, and to enable those skilled in the art to utilize the exemplary embodiments in various ways and with various modifications that are suitable for the particular use contemplated. The features of the embodiments described herein may be combined in all possible combinations of methods, apparatus, modules, systems, and computer program products. It should be understood that the exemplary embodiments presented herein can be implemented in any combination with each other.

[0056] It should be noted that the word "comprising" does not necessarily exclude the presence of other elements or steps than those listed, and the word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. It should be further noted that any reference signs are not intended to limit the scope of the claims, and that the exemplary embodiments may be implemented at least in part by means of both hardware and software, and that several "means", "units" or "devices" may be represented by the same item of hardware.

[0057] Various exemplary embodiments described herein are described in the general context of method steps or processes that may be implemented in one aspect by a computer program product embodied in a computer-readable medium, including computer-executable instructions, such as program code, executed by a computer in a networked environment. The computer-readable medium may include removable and non-removable storage devices, including, but not limited to, read-only memory (ROM), random access memory (RAM), compact discs (CDs), digital versatile discs (DVDs), and the like. Generally, program modules may include routines, programs, objects, components, data structures, and the like that perform particular tasks or implement particular abstract data types. Computer-executable instructions, associated data structures, and program modules represent examples of program code for executing steps of the methods disclosed herein. A particular sequence of such executable instructions or associated data structures represents examples of corresponding acts for implementing the functions described in such steps or processes.

[0058] In the drawings and specification, illustrative embodiments are disclosed. However, many variations and modifications of these embodiments are possible. Thus, although specific terms are employed, they are used in a generic and descriptive sense only and not for purposes of limitation, the scope of the embodiments being defined by the following claims.

Claims

1. 1. A method in an auxiliary device for monitoring modules and / or packs of an electric battery system, the electric battery system comprising at least one pack, each pack comprising at least one module, each module comprising a plurality of battery cells, each battery cell being monitored via a cell monitoring device, CMD, that provides cell-level measurements, the method comprising: obtaining, using at least one sensor included in the auxiliary device, module-level and / or pack-level measurements associated with the at least one module and / or the at least one pack, respectively, wherein the cell-level measurements are separate from the module-level and pack-level measurements; transmitting the module-level and / or pack-level measurements via a short-range wireless antenna of the auxiliary device to a centralized control unit via a short-range wireless communication bus, the centralized control unit configured to control operation of the electric battery system, the short-range wireless communication bus being utilized by each CMD in transmitting cell-level measurements to the centralized control unit via the short-range wireless antenna of each of the CMDs.

2. The electric battery system is contained within a housing, and the method comprises:

10. The method of claim 1, further comprising: using the at least one sensor to obtain additional measurements associated with an environment external to the enclosure of the electric battery system or at least one auxiliary system in a battery electric vehicle or battery energy storage system, the auxiliary system being separate and distinct from the electric battery system.

3. The method of claim 1 , wherein the electric battery system is an existing system and the auxiliary device is configured to be disposed within the electric battery system.

4. accumulating a stored history of past measurements; and / or The method of claim 1 , further comprising determining a control process based on the obtained module-level and / or pack-level measurements.

5. Determining the control process Controlling a fault indicator or signalling line connected to said at least one module; and / or Controlling the operation of a fan or other thermal management system of the electric battery system; and / or Controlling safety disconnect and interlock operations; and / or The method of claim 4 further comprising controlling a commutation switch.

6. The electric battery system is contained within an enclosure, the auxiliary device is located at a boundary of the enclosure of the at least one module, and the method comprises: terminating the short range communication bus; and / or The method of claim 1 , further comprising filtering electromagnetic, EM, interference from entering or exiting the enclosure of the at least one module.

7. powering the auxiliary device from the near field communication bus by using a bias tee mechanism; or powering the auxiliary device directly from the at least one battery module; or The method of claim 1 , further comprising powering the auxiliary device from an external source within the electric battery system.

8. receiving measurement and / or operating instructions from the centralized control unit; and / or The method of claim 1 , further comprising autonomously performing measurement and / or operational tasks.

9. The method of claim 1 , wherein the transmitted measurements further comprise transmitting the module-level and / or pack-level measurements using a unique identifier associated with the auxiliary device.

10. 1. An auxiliary device for monitoring modules and / or packs of an electric battery system, the electric battery system comprising at least one pack, each pack comprising at least one module, each module comprising a plurality of battery cells, each battery cell being monitored via a cell monitoring device, CMD, that provides cell level measurements, the auxiliary device comprising: at least one sensor configured to obtain module-level and / or pack-level measurements associated with the at least one module and / or the at least one pack, respectively, wherein the cell-level measurements are separate from the module-level and pack-level measurements; and an auxiliary device comprising: at least one radio frequency, RF antenna configured to transmit the module-level and / or pack-level measurements to a centralized control unit via a short-range wireless communication bus, the centralized control unit configured to control operation of the electric battery system; and at least one radio frequency, RF antenna utilized by each CMD in transmitting cell-level measurements to the centralized control unit via the CMD's respective short-range wireless antenna.

11. The auxiliary device of claim 10, wherein the auxiliary device is further configured to perform the steps of the method of any one of claims 2 and 4 to 9.

12. The auxiliary device of claim 10 , wherein the electric battery system is an existing system and the auxiliary device is configured to be disposed within the electric battery system.

13. The auxiliary device of claim 10 , wherein the at least one sensor is a temperature, current, and / or pressure sensor.

14. 10. A machine-readable storage medium storing a set of instructions executable by one or more processors of an auxiliary device for monitoring modules and / or packs of an electric battery system, the electric battery system comprising at least one pack, each pack comprising at least one module, each module comprising a plurality of battery cells, each battery cell being monitored via a cell monitoring device, CMD, that provides cell-level measurements, the set of instructions being configured to perform the method of any one of claims 1, 2 and 4-9.

Images