Electrical battery module

Abstract

An electrical battery module (100) of a traction battery of an electric vehicle, wherein the battery module (100) comprises a plurality of battery cells (1), wherein groups (AC) of battery cells (1) are each assigned measuring devices (2A-2C) with a data transmission device, wherein the battery module (100) has at least one master (5) with an interface (6) to a central battery management control unit, wherein the data transmission devices and the at least one master (5) comprise optical transmission paths, characterized in that the optical transmission path comprises a light guide (7, 8) which is assigned to two adjacent measuring devices or to a measuring device and the master (5), wherein the light guides (7, 8) are designed as Plexiglas discs.

Description

[0001] The invention relates to an electrical battery module.

[0002] Electric battery modules are used, for example, in electric vehicles as part of a traction battery. A battery module comprises a multitude of battery cells connected in series and / or parallel. Several battery modules are then connected in series and / or parallel to form a battery unit with the desired voltage and capacity. The individual battery modules are connected to a central control unit, the battery management control unit (BMU). The data connection between the control units of the battery modules and the central BMU is, for example, implemented as a CAN bus. Within each battery module, groups of battery cells are assigned measuring devices that, for example, record the voltage and temperature of the assigned battery cells and transmit this data to the central control unit of the battery module.This central control unit can also transmit control commands to the measuring devices, for example, to perform cell balancing. This central control unit of the battery module can also be referred to as the master. Data transmission between the measuring devices and the master can be electrical or optical.

[0003] From DE 10 2009 058 879 A1, a generic electrical energy storage system for an electric vehicle is known, comprising a plurality of electrical components and data transmission devices for transmitting data signals to and / or from at least one of the components. The data transmission devices include at least one transmission path for electromagnetic radiation for data transmission. Preferably, at least one transmission path is designed as an optical fiber for optical data signal transmission, wherein the optical fiber is preferably connected to the relevant component via a connector. It is also disclosed that at least one transmission path is designed as an optocoupler.

[0004] From DE 10 2012 202 690 A1, a vehicle is known with a data bus system and an electrical high-voltage storage device, which is integrated into the vehicle's data bus system and which includes a storage management unit and at least one cell module. The storage management unit is connected to the vehicle's data bus system. Furthermore, an electronic cell monitoring unit is assigned to the at least one cell module, and an optical data bus system connects the storage management unit and the electrical cell monitoring unit.

[0005] From DE 20 2016 007 525 U1, a battery management system with an optical communication interface for transmitting information such as battery status and temperature between different monitoring units is known, wherein preferably an optically communicating monitoring module monitors the data of single or multiple battery cells, wherein the optical communication interfaces are connected with optical fibers.

[0006] From EP 1 641 148 A1 a method for optimizing the light power in an optical network is known.

[0007] From DE 10 2017 204 138 A1, a battery unit is known comprising at least two battery modules and at least two measuring and control units, which are connected to at least one central control unit via data communication, wherein the data communication is implemented as optical free-space communication. The measuring and control units each have at least one optical transmitter and the at least one central control unit has at least one optical receiver, wherein the optical free-space communication between the measuring and control units and the central control unit takes place directly, excluding the other measuring and control units.

[0008] From WO 2014 / 094 744 A1, a battery system consisting of secondary cells is known, comprising a battery unit, at least one further battery and a control system for regulating the battery system voltage during the charging process, wherein the first battery and each further battery are each connected to a battery voltage regulator unit designed as a balancer for influencing the charging process, which measures various parameters such as battery temperature, applied voltage, and current flow and transmits them to a central processing unit, wherein the battery voltage regulator units are equipped with optocouplers comprising light transmitters and light receivers, via which determined data can be transmitted to other battery voltage regulator units.

[0009] From DE 31 03 884 A1 a remote control system for the selective control of consumers is known, wherein a control line consists of an optical fiber which transmits the signals by means of cyclic light pulse sequences between a transmitting station and the receiving stations.

[0010] The invention is based on the technical problem of creating an electrical battery module with an alternative transmission path for the data.

[0011] The solution to the technical problem is achieved by a battery module having the features of claim 1 or 6. Further advantageous embodiments of the invention are set forth in the dependent claims.

[0012] The electrical battery module of an electric vehicle's traction battery comprises a multitude of battery cells, each group of which is assigned to measuring devices with a data transmission device. The battery module includes at least one master with an interface to a battery management control unit, where the data transmission devices and the at least one master are optical transmission links. Each optical transmission link includes a fiber optic cable that is assigned to two adjacent measuring devices or to one measuring device and the master. The advantage of such a daisy-chain network with shared fiber optic cables is that the associated data transmission is similar to electrical data transmission. Thus, the existing circuit board and its logic can largely be reused, with only the conversion of electrical signals into optical signals requiring a separate device.Conversely, this must be implemented. For example, a group contains 4 to 12 battery cells. The master's interface to the bus system is preferably a CAN interface. Alternatively, this interface can also be a FlexRay interface. However, this interface can also be a radio or optical interface. The measuring devices can additionally include control units to perform cell balancing. The light guides are designed as plexiglass discs, which is particularly cost-effective.

[0013] In one embodiment, an optical transmitter of one measuring device and an optical receiver of the other measuring device are each assigned to the respective light guide, with a light guide being assigned to the master and the last measuring device, so that a ring structure is created.

[0014] In an alternative embodiment, an optical transmitter and receiver of one measuring device and an optical transmitter and receiver of the other measuring device are each assigned to the respective optical fiber, wherein the transmitters and receivers of the measuring devices are configured to couple light in or out of two optical fibers. This creates an open chain, which is sometimes faster than a ring structure.

[0015] In one embodiment, the measuring devices each have two optical transmitters and two optical receivers, with one transmitter and one receiver assigned to a single optical fiber. This simplifies the assignment to two optical fibers, but increases the number of components required.

[0016] In an alternative embodiment, the transmitters and receivers are designed in such a way that their radiation characteristics and reception characteristics can be changed, so that the number of components is minimal.

[0017] In an alternative embodiment, the battery module comprises a plurality of battery cells, with each group of battery cells being assigned measuring devices with a data transmission device. The battery module includes at least one master with an interface to a battery management control unit. The data transmission device and the at least one master comprise optical transmission links, the transmission links between the measuring devices and the master being via a common optical fiber. The measuring devices and the master are configured as a meshed optical network. This allows for very robust and fast data transmission, since meshed networks are generally self-healing. The optical fiber for the meshed network is a Plexiglas sheet. Preferably, the measuring devices and the master can be configured as a fully meshed optical network.

[0018] The invention is explained in more detail below with reference to preferred embodiments. The figures show: Fig. 1 a schematic partial representation of a battery module in a first embodiment, Fig. 2 a schematic partial representation of a battery module in a second embodiment, Fig. 3 a schematic partial representation of a battery module in a third embodiment, Fig. 4 a schematic partial representation of a battery module in a fourth non-claimed embodiment and Fig. 5 a schematic partial representation of a battery module in a fifth embodiment.

[0019] In the Fig. Figure 1 schematically depicts a part of a battery module 100. The battery module 100 comprises a multitude of battery cells 1 connected in series. Additional battery cells 1 can also be connected in parallel, but this is not shown for clarity. The battery cells 1 are divided into groups, for example, groups A, B, and C, each with a measuring device 2A, 2B, and 2C, respectively. Measuring devices 2A-2C each have an optical transmitter 3, which may be an LED. Furthermore, measuring devices 2A-2C each have an optical receiver 4, which may be a phototransistor. The battery module 100 also includes a master 5, which likewise has an optical transmitter 3 and an optical receiver 4. The master 5 additionally has an interface 6 to a battery management control unit (not shown).The battery module 100 has several light guides 7, 8 which are designed as plexiglass discs.

[0020] The optical fibers 7 are each arranged such that an optical transmitter 3 of the master 5 or a measuring device 2A-2B and an optical receiver 4 of an adjacent measuring device 2A-2C are assigned to one optical fiber 7. The optical transmitter 3 of the last measuring device 2C is coupled to the optical receiver 4 of the master 5 via the optical fiber 8.

[0021] If, for example, Master 5 wants to transmit a control command to measuring device 2C, Master 5 sends this control command via its optical transmitter 3 through the first optical fiber 7 to measuring device 2A. There, the optical control command is received and it is determined that it is intended for measuring device 2C. Measuring device 2A then forwards the control command to measuring device 2B, and this device finally forwards it to measuring device 2C. Measuring devices 2A-2C transmit their measurement data to Master 5 in the same way. Thus, a ring topology exists.

[0022] In the Fig. Figure 2 shows an alternative embodiment of a battery module 100, where the battery cells 1 are not shown. In contrast to the embodiment according to Fig. 1. The optical transmitters 3 and the optical receivers 4 of the measuring devices 2A, 2B can change their transmitting characteristics or their receiving characteristics so that they can transmit in both directions and receive from both directions.

[0023] In the Fig. 3 is a similar embodiment to that in Fig. Figure 2 shows the difference between the two measuring devices 2A and 2B, each having two optical transmitters 3 and two optical receivers 4. This requires more components, but the optical transmitters 3 and receivers 4 no longer need to be able to change their characteristics.

[0024] In the Fig. Figure 4 shows a fourth embodiment for a battery module 100, wherein the transmission paths between the measuring devices 2A-2C and the master 5 are designed as free-space optical transmission, with the communication being bidirectional. A housing wall 9 can be used for this purpose, at which the optical signals are reflected.

[0025] In the Fig. Figure 5 shows a fifth embodiment for a battery module 100, wherein the transmission links between the measuring devices 2A-2C and the master 5 are via a common optical fiber 10, and the measuring devices 2A-2C and the master 5 are configured as a meshed optical network. In a meshed network, each network node is connected to one or more other nodes. When every node is connected to every other node, it is called a fully meshed network.

[0026] To explain the operating mode, it should first be assumed that the measuring devices 2A-2C and the master form a fully meshed network. In this case, each measuring device 2A-2C can communicate directly with the master 5 and vice versa. Preferably, this communication takes place via a handshake procedure. Therefore, the failure of one measuring device 2A-2C does not lead to a total failure; rather, only the defective measuring device no longer transmits data or can no longer receive control commands.

[0027] If the network is not fully meshed, it only needs to be ensured that a measuring device 2A-2C can communicate with two or more neighboring measuring devices on each side in order to be able to bypass a defective measuring device.

[0028] For example, if measuring device 2C attempts to transmit data to master 5, this data is also received by measuring devices 2B and 2A, which recognize that the data is not intended for them. Measuring devices 2B and 2A then temporarily store the data from measuring device 2C. If master 5 then sends an acknowledgment signal to measuring device 2C, this acknowledgment signal is also received by measuring devices 2A and 2B, and the temporarily stored data can be deleted. If, however, they do not receive the acknowledgment signal, measuring devices 2A and / or 2B can resend the temporarily stored data from measuring device 2C and wait to see if master 5 acknowledges receipt. Such a mesh network is therefore very robust against failures and transmission problems. It should be noted that all nodes can transmit in all directions, and nodes are also permitted to transmit simultaneously.The optical waveguide 10 is designed as a plexiglass disc.

Claims

[1] Electrical battery module (100) of a traction battery of an electric vehicle, wherein the battery module (100) comprises a plurality of battery cells (1), wherein groups (AC) of battery cells (1) are each assigned measuring devices (2A-2C) with a data transmission device, wherein the battery module (100) comprises at least one master (5) with an interface (6) to a central battery management control unit, wherein the data transmission devices and the at least one master (5) comprise optical transmission links, characterized by , that the optical transmission path comprises a light guide (7, 8) which is assigned to two adjacent measuring devices or to a measuring device and the master (5), wherein the light guides (7, 8) are designed as Plexiglas discs. [2] Electrical battery module (100) according to claim 1, characterized by, that each optical transmitter (3) of one measuring device (2A-2B) and optical receiver (4) of the other measuring device (2B-2C) are assigned to the respective optical fiber (7), wherein the master (5) and the last measuring device (2C) are assigned an optical fiber (8). [3] Electrical battery module (100) according to claim 1, characterized by , that one optical transmitter (3) and receiver (4) of one measuring device (2A-2B) and one optical transmitter (3) and receiver (4) of the other measuring device (2B-2A) are each assigned to the respective optical fiber (7), wherein the transmitters (3) and receivers (4) of the measuring devices (2A-2B) are configured to couple light into or out of two optical fibers (7). [4] Electrical battery module (100) according to claim 3, characterized by, that the measuring devices (2A, 2B) each have two optical transmitters (3) and two optical receivers (4), wherein one transmitter (3) and one receiver (4) are each assigned to a light guide (7). [5] Electrical battery module (100) according to claim 3, characterized by , that the transmitters (3) and receivers (4) are designed such that their emission characteristics and reception characteristics are variable. [6] Electrical battery module (100) of a traction battery of an electric vehicle, wherein the battery module (100) comprises a plurality of battery cells (1), wherein groups (AC) of battery cells (1) are each assigned measuring devices (2A-2C) with a data transmission device, wherein the battery module (100) comprises at least one master (5) with an interface to a central battery management control unit, wherein the data transmission device and the at least one master (5) comprise optical transmission links, characterized by, that the transmission links between the measuring devices (2A-2C) and the master (5) are via a common optical waveguide (10), wherein the measuring devices (2A-2C) and the master (5) are configured as a meshed optical network, wherein the common optical waveguide (10) is designed as a Plexiglas disc. [7] Electrical battery module (100) according to claim 6, characterized by , that the measuring devices (2A-2C) and the master (5) are configured as a fully meshed optical network.

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