Modular battery system

Abstract

A modular battery system comprises a battery pack with multiple battery modules electrically interconnected via a multitude of electrical cables. A multitude of switches selectively connects the multiple battery modules. A DC charging connector is configured to electrically connect the battery pack to an external DC fast charging station via the multitude of electrical cables. The pack's circuitry is designed to switch between a first and second configuration based on the respective position of the multitude of switches. A controller is configured to select the respective position of each of the multitude of switches to toggle the pack's circuitry between the first and second configurations in response to input signals indicating a requested operating mode of the battery pack.The first configuration offers three parallel electrical paths, and the second configuration offers two parallel electrical paths.

Description

[0001] This description generally relates to a modular battery system and a motor vehicle equipped therewith. More specifically, the description relates to a modular battery system that is switchable between parallel configurations. The use of mobile platforms that utilize a rechargeable energy source, both as an exclusive and non-exclusive energy source, has increased significantly in recent years. A rechargeable energy storage device with battery packs can store electrochemical energy and release it as needed in a specific operating mode. The electrochemical energy can be used for propulsion, heating or cooling the vehicle interior, powering vehicle accessories, and other purposes.

[0002] DE 10 2014 004 790 A1 describes a method for operating an energy storage device with at least one first energy storage element and at least one second energy storage element connected in parallel to the first energy storage element in a motor vehicle, wherein the first and the second energy storage element are connected in series to the vehicle-external energy source by a switching device when a charging condition indicating energy provision for charging the energy storage device by an energy source external to the vehicle is met.

[0003] US 2017 / 0 201 102 A1 describes a two-terminal circuit with a relatively high series degree, which is configured by interconnecting a plurality of power storage elements. Charging of the power storage elements is initiated by applying a current to this two-terminal circuit. After the connection of the power storage elements is changed to reduce the series degree and a voltage fluctuation between the power storage elements is resolved at a predetermined time, a connection change is made to reconfigure a two-terminal circuit with a high series degree, and the charging process is continued. Each power storage element can be charged in a short time while equalizing the voltages between the power storage elements.

[0004] DE 10 2022 108 841 A1 describes a charging system comprising a scalable power source for supplying power to a vehicle engine, and telematics and battery management modules. The scalable power source contains: N battery assemblies, where N is an integer greater than or equal to 3; and a plurality of switches connected to the N battery assemblies, including N - 1 switches for connecting the N battery assemblies in series between supply and return lines and multiple N switches for connecting the N battery assemblies in parallel to the supply and return lines. The telematics module requests the capability of a charging station and receives a response signal from a device indicating the capability of the charging station.The battery management module: selects one of the available configurations in which to connect the N battery assemblies based on the capability of the charging station, determines the states of the plurality of switches, and then charges the N battery assemblies based on the states. It may be considered an object to provide an improved battery system. The invention relates to a battery system according to claim 1. The description also describes an exemplary vehicle that can be operated with the battery system according to the invention.

[0005] A modular battery system according to the invention comprises a battery pack with a plurality of battery modules and a plurality of electrical cables. The plurality of battery modules are electrically connected to one another via the plurality of electrical cables in a pack circuit. The system includes a plurality of switches that selectively connect the plurality of battery modules. The plurality of battery modules are divided into a first group, a second group, a third group, and a fourth group. A DC charging connector is configured to electrically connect the battery pack to an on-board DC fast charging station via the plurality of electrical cables. The battery pack can be selectively connected to a drive output.

[0006] According to the invention, the pack circuit is configured such that the pack circuit switches between a first configuration and a second configuration based on a respective position of the plurality of switches. A controller is configured to select the respective position of each of the plurality of switches to switch the pack circuit between the first configuration and the second configuration in response to input signals indicating a requested operating mode of the battery pack. Respective battery cells in the pack circuit are arranged in a combination of series circuits and parallel circuits. The first configuration provides three parallel electrical paths, and the second configuration provides two parallel electrical paths.The parallel electrical paths refer to individual battery cells arranged in parallel or to groups of battery cells arranged in parallel.

[0007] The first configuration may represent a drive mode, and the second configuration may represent a charge mode. In one embodiment, the first configuration provides a drive power of approximately 400 volts, and the second configuration provides a charge power of approximately 600 volts.

[0008] According to the invention, the plurality of battery modules are divided into a first group, a second group, a third group, and a fourth group. The first group comprises two modules arranged at a negative end of the pack circuit, and the fourth group comprises two further modules arranged at a positive end of the pack circuit. The second group and the third group each contain a single module arranged in the center of the pack circuit.

[0009] According to the invention, the plurality of switches comprise a first load switch configured to electrically connect the pack circuit to a positive branch of the drive output, and a second load switch configured to electrically connect the pack circuit to a negative branch of the drive output. The plurality of switches may comprise a first charging switch configured to electrically connect the pack circuit to the positive branch of the DC charging terminal, and a second charging switch configured to electrically connect the pack circuit to the negative branch of the DC charging terminal.

[0010] According to the invention, the first group comprises one third of the respective battery cells in the pack circuit, the fourth group comprises another third of the respective battery cells in the pack circuit, and the second group and the third group together comprise a remaining third of the respective battery cells of the pack circuit.

[0011] According to the invention, the plurality of switches comprises a central switch configured to electrically connect, in a respective closed position, a respective positive branch of the second group to the respective positive branch of the first group and a respective negative branch of the fourth group to the respective positive branch of the first group.

[0012] In one embodiment, at least one of the plurality of switches is an electromechanical contactor. In one embodiment, at least one of the plurality of switches is a solid-state switch and / or a diode.

[0013] According to the invention, the first configuration is achieved when: the central switch is in the respective closed position; a first load switch and a second load switch electrically connect the pack circuit to the drive output; the respective negative branch of the second group is selectively connected to the drive output; and the respective positive branch of the third group is selectively connected to the drive output. The second configuration can be achieved when: the central switch is in a corresponding open position; a first charging switch and a second charging switch electrically connect the pack circuit to the DC charging port; the corresponding positive branch of the first group is selectively connected to the corresponding negative branch of the second group; and the corresponding positive branch of the third group is selectively connected to the corresponding negative branch of the fourth group.

[0014] According to the invention, the plurality of switches comprises a first two-way switch with two closed positions. In one of the two closed positions, the first two-way switch is configured to electrically connect the respective negative branch of the second group to the drive output. In another of the two closed positions, the first two-way switch is configured to electrically connect the respective positive branch of the first group to the respective negative branch of the second group.

[0015] According to the invention, the plurality of switches comprises a second two-way switch with two closed positions. In one of the two closed positions, the second two-way switch is configured to electrically connect the respective positive branch of the third group to the drive output. In another of the two closed positions, the second two-way switch is configured to electrically connect the respective positive branch of the third group to the respective negative branch of the fourth group.

[0016] An exemplary motor vehicle having a battery pack with a plurality of battery modules and a plurality of electrical cables. The plurality of battery modules are electrically connected to one another via the plurality of electrical cables in a pack circuit. The battery pack is selectively connectable to a propulsion output to generate propulsion power for the vehicle. The battery pack includes a DC charging connector configured to electrically connect the battery pack to an on-board DC rapid charging station via the plurality of electrical cables, wherein the plurality of battery modules are divided into a first group, a second group, a third group, and a fourth group.The battery pack includes a plurality of switches that selectively connect the plurality of battery modules, the pack circuitry configured to switch between a first configuration and a second configuration based on a respective position of the plurality of switches. A controller is configured to select the respective position of each of the plurality of switches to switch the pack circuitry between the first configuration and the second configuration in response to input signals indicating a requested operating mode of the battery pack. The first configuration provides three parallel electrical paths, and the second configuration provides two parallel electrical paths. Fig. 1 is a schematic diagram of a modular battery system with multiple battery modules; Fig. Figure 2 is a schematic diagram of an exemplary packet circuit used in the system of Fig. 1, wherein the packet circuit is in a first configuration; and Fig. 3 is a schematic diagram of the Fig. 2, wherein the packet circuit is in a second configuration.

[0017] With reference to the drawings, in which like reference numbers refer to like components, Fig. 1 schematically illustrates a modular battery system 10 comprising a battery pack 12 with multiple battery modules 14. Each of the modules 14 may contain corresponding battery cells with different chemistries, including, but not limited to, lithium-ion, lithium-iron, nickel-metal hydride, and lead-acid batteries. It is understood that the number of battery cells in each module and the number of modules in the battery pack 12 may vary depending on the application.

[0018] The modular battery system 10 can be part of a rechargeable energy storage system for powering a vehicle 16. The vehicle 16 can be partially or fully electric.

[0019] The vehicle 16 may be a mobile platform, such as a passenger car, a sport utility vehicle, a light truck, a heavy-duty vehicle, an ATV, a minivan, a bus, a transit vehicle, a bicycle, a mobile robot, an agricultural implement (e.g., a tractor), a sporting device (e.g., a golf cart), a boat, an aircraft, or a train. It should be understood that the vehicle 16 may take many different forms and have additional components.

[0020] Switchable battery circuits face limitations when implementing different configurations. For example, a circuit with a 2:1 switchable configuration (with two parallel electrical paths in one configuration and one parallel electrical path in another configuration) is unable to support a 300-cell battery pack with a 3P100S configuration to switch to a higher voltage for charging. The number before the P represents the number of parallel batteries in the battery pack (12), and the number before the S represents the number of battery cells in series. This is because the integers in the ratio represent real cells that are not divisible. Therefore, it is not trivial to design battery pack circuits with switchable configurations in a specific ratio to meet various component reuse, packaging, and voltage requirements.

[0021] As described below, the battery pack 12 includes a special set of modules, switches, and connections that allow the battery pack 12 to switch between a first configuration 100 and a second configuration 200, as shown in the Fig. 2-3. The first configuration 100 provides three parallel electrical paths (3P mode), and the second configuration 200 provides two parallel electrical paths (2P mode). The structure described below enables a 3:2 ratio, so that a battery pack 12 with a 3P100S configuration can easily convert to a 2P150S configuration.

[0022] As in the Fig. 2 to 3, the plurality of battery modules 14 are electrically connected to one another via a plurality of electrical cables 18 in a pack circuit 20. The pack circuit 20 includes a plurality of switches 22 suitable for selectively connecting the plurality of battery modules 14. Referring to Fig. 1, the modular battery system 10 includes a controller C configured to select the respective position of each of the plurality of switches 22 to switch the pack circuit 20 between the first configuration 100 and the second configuration 200 in response to input signals indicative of a requested operating mode of the battery pack 12.

[0023] As in Fig. 1, the controller C includes at least one processor P and at least one memory M (or a non-transitory, tangible, computer-readable storage medium) in which instructions for controlling the operation of the plurality of switches 22 are recorded. The memory M can store executable instruction sets, and the processor P can execute the instruction sets stored in the memory M. The modular battery system 10 avoids the redesign of motors and inverters by using the same circuitry for different operating modes.

[0024] As in the Fig. 2-3, the plurality of battery modules 14 may be selectively connected to a DC charging port 24 via one of the plurality of electrical cables 18. Referring to Fig. 1, the vehicle 16 can be subjected to a DC fast charging process in which the battery pack 12 is electrically connected to an external DC fast charging station 26 via a vehicle charging port 28. The battery pack 12 is connected to the charging port 28, which can be selectively coupled to the external DC fast charging station 26 via additional attachments, such as the connector 25.

[0025] As in the Fig. 2 and Fig. 3, the plurality of battery modules 14 are divided into a first group 30, a second group 32, a third group 34, and a fourth group 36. The first group 30 includes two modules 14A, 14B positioned at a (most) negative end of the pack circuit 20, as shown in Fig. 2. The fourth group 36 comprises two modules 14E, 14F arranged at a (most) positive end of the package circuit 20. The second group 32 and the third group 34 each comprise a single module 14C, 14D arranged in the center of the package circuit 20, as shown in Fig. 2 shown.

[0026] The parallel electrical paths refer to individual or groups of n cells connected in parallel. The respective battery cells in the pack circuit 20 are arranged in a combination of series and parallel connections. The total number of cells in the circuit can be (SXP), which are arranged so that the current is evenly distributed among each cell and the voltage drop is evenly distributed across each of the battery cells. In the first configuration 100, the parallel number P is 3 / 2 and the series number S is 2 / 3, compared to the second configuration 200. The first group 30 and the fourth group 36 can consist of two modules connected in series or of two modules connected in parallel, each having the same number of cells. In the examples shown, the minimum number of parallel-connected cells is used, i.e.1P and 2P, but it is understood that larger packs of 2P and 4P modules can be manufactured using the same cells to achieve higher energy capacity. If the battery pack 12 is constructed from smaller cells (e.g., cylindrical), a larger number of cells can also be used, e.g., ten cells in parallel for the second group 32 and the third group 34, and twenty cells in parallel for the first group 30 and the fourth group 36.

[0027] In some embodiments, the first group 30 comprises one-third of the respective battery cells, and the fourth group 36 comprises another third of the respective battery cells in the pack circuit 20. The second group 32 and the third group 34 together comprise a remaining third of the respective battery cells of the pack circuit 20.

[0028] The pack circuit 20 enables the battery pack 12 to switch between a first configuration 100 (3P mode with three parallel cells in each group) and a second configuration 200 (2P mode with two parallel cells in each group) so that the battery pack 12 can generate an ideal voltage under various operating conditions. In the illustrated embodiment, the first configuration 100 represents a drive mode and the second configuration 200 represents a charge mode. In one example, the first configuration 100 provides a drive power of approximately 400 volts and the second configuration 200 provides a charge power of approximately 600 volts.

[0029] With reference to the Fig. 2-3, the plurality of switches 22 includes a first load switch 40, a second load switch 42, a first charging switch 44, a second charging switch 46, and a central switch 48. In one embodiment, the plurality of switches 22 includes at least one electromechanical contactor. The plurality of switches 22 may include at least one solid-state switch and / or a diode. It is understood that the plurality of switches 22 may include additional components and take different forms.

[0030] With reference to the Fig. 2-3, the first load switch 40 is configured to electrically connect the pack circuit 20 to a negative leg of a drive output 50 (via the drive port 52). The drive output 50 transfers drive power to one or more electric machines for use by the vehicle 16. The second load switch 42 is configured to electrically connect the pack circuit 20 to a positive leg of the drive output 50. The first charge switch 44 is configured to electrically connect the pack circuit 20 to a negative leg of the DC charge port 24. The second charge switch 46 is configured to electrically connect the pack circuit 20 to a positive leg of the DC charge port 24.

[0031] The plurality of switches 22 may include a first two-way switch 60 and a second two-way switch 62. Alternatively, the first two-way switch 60 and the second two-way switch 62 may each be replaced by two one-way switches. As shown in the Fig. As shown in Figure 2-3, the first two-way switch 60 has a first node N1 that can be alternately connected to a second node N2 and a third node N3. The second two-way switch 62 has a node, referred to here as the fourth node N4, that can be alternately connected to a fifth node N5 and a sixth node N6. In other words, the first two-way switch 60 and the second two-way switch 62 each have two closed positions. Referring to Fig. 2, the first configuration 100 of the packet circuit 20 is achieved when the central switch 48

[0032] is in a corresponding closed position, the first node N1 of the first two-way switch 60 is electrically connected to the second node N2, and the fourth node N4 of the second two-way switch 62 is electrically connected to the fifth node N5. When the central switch 48 is closed, it electrically connects a respective positive branch of the second group 32 to the respective positive branch of the first group 30 and the respective negative branch of the fourth group 36 to the respective positive branch of the first group 30. In addition, the first load switch 40 and the second load switch 42 are closed, so that the drive output 50 is electrically connected to the pack circuit 20. In the first configuration 100, the first charge switch 44 and the second charge switch 46 are in their respective open positions.

[0033] In the first configuration 100 in Fig. 2, when the first node N1 of the first two-way switch 60 is electrically connected to the second node N2, the respective negative branch of the second group 32 is electrically connected to the drive output 50. When the fourth node N4 of the second two-way switch 62 is electrically connected to the fifth node N5, the respective positive branch of the third group 34 is electrically connected to the drive output 50.

[0034] As in Fig. 3, the second configuration 200 is achieved when the central switch 48 is in a corresponding open position, the first node N1 of the first two-way switch 60 is electrically connected to the third node N3, and the fourth node N4 of the second two-way switch 62 is electrically connected to the sixth node N6. In the second configuration 200, which is shown in Fig. 3, the battery pack 12 is being charged. Furthermore, in the second configuration 200, the first load switch 40 and the second load switch 42 are in their respective open positions. The first charge switch 44 and the second charge switch 46 are closed, electrically connecting the pack circuit 20 to the negative and positive legs of the DC charge terminal 24, respectively.

[0035] In the second configuration 200 in Fig. 3, when the first node N1 of the first two-way switch 60 is connected to the third node N3, the respective positive branch of the first group 30 is electrically connected to the respective negative branch of the second group 32. When the fourth node N4 of the second two-way switch 62 is connected to the sixth node N6, the respective positive branch of the third group 34 is connected to the respective negative branch of the fourth group 36.

[0036] As in Fig. 1, the battery pack 12 may include a management unit 70 embedded in a microcircuit. The microcircuit may be an assembly of electronic components, the core of which is a microcontroller and which includes a wireless communication interface available to one skilled in the art. The microcircuit may include an associated memory, an associated processor, and an integrated electronic controller, such as an application-specific integrated circuit (ASIC). As shown in Fig. As shown in Figure 1, a packet communicator 72 may be connected to the controller C, e.g., via a communications bus, which may be a serial communications bus in the form of a local area network. The controller C (via the packet communicator 72) may be connected to the battery pack 12 (via the management unit 70) via a wireless network 74.

[0037] The wireless network 74 may be a short-range or long-range network. The wireless network 74 of Fig. 1 can be a wireless local area network (LAN) that connects multiple devices using a wireless distribution method, a wireless metropolitan area network (MAN) that connects multiple wireless LANs, or a wireless wide area network (WAN) that covers large areas such as neighboring cities. The wireless network 74 can be a WIFI or a Bluetooth™ connection, which is defined as a short-range radio technology (or wireless technology) for facilitating communication between Internet devices and between devices and the Internet. Bluetooth™ is an open wireless technology standard for transmitting data from fixed and mobile electronic devices over short distances, creating personal networks operating in the 2.4 GHz band. Other types of connections may also be used.

[0038] In summary, the modular battery system 10 includes a specific set of modules, switches, and connections that enable the battery pack 12 to efficiently switch between the first configuration 100 (3P mode) and the second configuration 200 (2P mode). In one embodiment, the modular battery system 10 is deployed in an electric vehicle 16 that generates a propulsion power of approximately 400 volts in the first configuration 100 and a charging voltage of approximately 600 volts in the second configuration 200. The ability to switch from a higher charging voltage (e.g., 600 volts) to a lower propulsion voltage (e.g., 400 volts) avoids the application of overvoltage to the propulsion components compared to a non-switched 600-volt system.Alternatively, it avoids excessive current flowing through the charging port / connector at the same power or charging at a lower power level than with a non-switched 400-volt system at the same current.

[0039] The control C of Fig. 1 may be an integral component or a separate module operatively connected to other controls of the vehicle 16. The control C of Fig.1 includes a computer-readable medium (also called a processor-readable medium), including a non-transitory (e.g., tangible) medium that participates in the provision of data (e.g., instructions) that can be read by a computer (e.g., by a processor of a computer). Such a medium may take many forms, including, but not limited to, non-volatile media and volatile media. Non-volatile media includes, for example, optical or magnetic hard disks and other persistent storage. Volatile media may include, for example, dynamic random access memory (DRAM), which may constitute main memory. Such instructions may be transmitted over one or more transmission media, including coaxial cable, copper cable, and fiber optic cable, including the wires that form a system bus connected to a processor of a computer.Some forms of computer-readable media include, for example, a floppy disk, a flexible disk, a hard disk, a magnetic tape, another magnetic medium, a CD-ROM, a DVD, another optical medium, a physical medium with hole patterns, a RAM, a PROM, an EPROM, a FLASH EEPROM, another memory chip, or a cartridge or other medium that a computer can read from.

[0040] Lookup tables, databases, data warehouses, or other data stores described herein may include various types of mechanisms for storing, accessing, and retrieving various types of data, including a hierarchical database, a set of files in a file system, an application database in a proprietary format, a relational database management system (RDBMS), etc. Each of these data stores may be embodied in a computing device using a computer operating system such as one of those mentioned above and may be accessible over a network in one or more of the various ways. A file system may be accessed from a computer operating system and may contain files stored in various formats.An RDBMS may use the Structured Query Language (SQL) in addition to a language for creating, storing, editing, and executing stored procedures, such as the PL / SQL language mentioned above.

Claims

[1] Modular battery system (10), comprising: a battery pack (12) having a plurality of battery modules (14) and a plurality of electrical cables (18), wherein the plurality of battery modules (14) are electrically connected to one another via the plurality of electrical cables (18) in a pack circuit (20), wherein the plurality of battery modules (14) are divided into a first group (30), a second group (32), a third group (34) and a fourth group (36); a DC charging connector (25) configured to electrically connect the battery pack (12) to an off-board DC rapid charging station (26) via the plurality of electrical cables (18), the battery pack (12) being selectively connectable to a drive output (50); a plurality of switches (22) selectively connecting the plurality of battery modules (14), wherein the pack circuit (20) is configured such that the pack circuit (20) switches between a first configuration (100) and a second configuration (200) based on a respective position of the plurality of switches (22); a controller (C) having a processor (P) and a tangible, non-transitory memory (M) in which instructions are recorded, the controller (C) being adapted to select the respective position of the plurality of switches (22) to switch the pack circuit (20) between the first configuration (100) and the second configuration (200) in response to input signals indicating a requested operating mode of the battery pack (12); wherein respective battery cells in the pack circuit (20) are arranged in a combination of series circuits and parallel circuits; wherein the first configuration (100) provides three parallel electrical paths and the second configuration (200) provides two parallel electrical paths, wherein the parallel electrical paths relate to individual ones of the respective parallel-arranged battery cells or to groups (30, 32, 34, 36) of the respective parallel-arranged battery cells; wherein the first group (30) comprises two modules (14A, 14B) arranged at a negative end of the package circuit (20), the fourth group (36) comprises two further modules (14E, 14F) arranged at a positive end of the package circuit (20); wherein the second group (32) and the third group (34) each comprise a single module (14C, 14D) arranged in a center of the package circuit (20); wherein the first group (30) comprises one-third of the respective battery cells in the pack circuit (20); the fourth group (36) comprises a further third of the respective battery cells in the pack circuit (20); the second group (32) and the third group (34) together comprise a remaining third of the respective battery cells of the pack circuit (20); wherein the plurality of switches (22) comprises a central switch (48) configured to, when in a corresponding closed position, establish an electrical connection between: a respective positive branch of the second group (32) and the respective positive branch of the first group (30); and a respective negative branch of the fourth group (36) with the respective positive branch of the first group (30); where the first configuration (100) is achieved when: the central switch (48) is in the respective closed position; a first load switch (40) and a second load switch (42) electrically connect the packet circuit (20) to the drive output (50); the respective negative branch of the second group (32) is selectively connected to the drive output (50); and the respective positive branch of the third group (34) is selectively connected to the drive output (50); wherein the second configuration (200) is achieved when: the central switch (48) is in a corresponding open position; a first charging switch (44) and a second charging switch (46) electrically connect the pack circuit (20) to the DC charging port (24); the respective positive branch of the first group (30) is selectively connected to the respective negative branch of the second group (32); and the respective positive branch of the third group (34) with the respective negative branch of the fourth group (36); wherein the plurality of switches (22) comprises a first two-way switch (60) having two closed positions; wherein in one of the two closed positions, the first two-way switch (60) is configured to electrically connect the respective negative branch of the second group (32) to the drive output (50); and wherein in another of the two closed positions, the first two-way switch (60) is configured to electrically connect the respective positive branch of the first group (30) to the respective negative branch of the second group (32); and wherein the plurality of switches (22) comprises a second two-way switch (62) having two closed positions; wherein in one of the two closed positions, the second two-way switch (62) is configured to electrically connect the respective positive branch of the third group (34) to the drive output (50); and wherein in another of the two closed positions, the second two-way switch (62) is configured to electrically connect the respective positive branch of the third group (34) to the respective negative branch of the fourth group (36). [2] The system (10) of claim 1, wherein the first configuration (100) represents a drive mode and the second configuration (200) represents a charge mode. [3] The system (10) of claim 1, wherein the plurality of switches (22) comprises: a first load switch (40) configured to electrically connect the pack circuit (20) to a positive leg of the drive output (50); a second load switch (42) configured to electrically connect the pack circuit (20) to a negative branch of the drive output (50); a first charging switch (44) configured to electrically connect the pack circuit (20) to the positive leg of the DC charging terminal (24); and a second charging switch (46) configured to electrically connect the pack circuit (20) to the negative leg of the DC charging terminal (24).

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