Cell system

Abstract

To achieve both improved energy density and the prevention of deterioration in communication reliability.SOLUTION: A cell system 1 includes a first stack 10 to a fourth stack 40, a first monitoring unit 12 to a fourth monitoring unit 42, and an ECU 4. The first monitoring unit 12 and the second monitoring unit are provided between the first stack 10 and the second stack 20. A J / B2 including the ECU 4 is provided at a position where there is no obstruction between it and the first monitoring unit 12. The second monitoring unit 22 is provided at a position where the distance to the J / B2 is longer than that of the first monitoring unit 12. The second monitoring unit 22 and the J / B2 are connected by a waveguide 21.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a battery system. [Background technology]

[0002] For example, JP 2021-131986 A (Patent Document 1) discloses a battery module having multiple battery cells, an individual communication unit at the top of each of the multiple battery cells that outputs information to a monitoring unit via a wireless signal, and a waveguide between the individual communication unit and the monitoring unit. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2021-131986 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, when an individual communication unit is provided on the top of a battery stack composed of multiple battery cells, the space in the vertical direction increases, which may result in a decrease in energy density. Furthermore, when multiple individual communication units are provided between the stacks in order to improve the energy density, the reliability of communication may decrease.

[0005] The present disclosure has been made to solve the above-mentioned problems, and its purpose is to provide a battery system that achieves both improved energy density and suppression of deterioration in communication reliability. [Means for solving the problem]

[0006] A battery system according to an aspect of the present disclosure includes a plurality of battery modules arranged in a predetermined direction, a plurality of monitoring devices provided in each of the plurality of battery modules for monitoring a battery state, and a control device that wirelessly communicates with each of the plurality of monitoring devices. A first monitoring device and a second monitoring device corresponding to two adjacent battery modules among the plurality of battery modules are provided between the two adjacent battery modules. The control device is provided at a position where there is no obstruction between the first monitoring device and the control device. The second monitoring device is provided at a position where the distance to the control device is longer than that of the first monitoring device. The second monitoring device and the control device are connected by a waveguide.

[0007] In this way, the first monitoring device is installed in a position where there are no obstructions between it and the control device, ensuring reliability of communication. The second monitoring device communicates with the control device via a waveguide, ensuring reliability of communication. Furthermore, the first monitoring device and the second monitoring device are installed between two adjacent battery modules, improving energy density. Effect of the Invention

[0008] According to the present disclosure, it is possible to provide a battery system that achieves both improved energy density and suppression of deterioration in communication reliability. [Brief description of the drawings]

[0009] [Figure 1] 1 is a diagram showing an example of a configuration of a battery system according to an embodiment of the present invention; [Diagram 2] FIG. 13 is a diagram showing an example of a configuration of a battery system according to a modified example. [Diagram 3] FIG. 13 is a diagram showing another example of the configuration of a battery system according to a modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are designated by the same reference characters and their description will not be repeated.

[0011] FIG. 1 is a diagram showing an example of the configuration of a battery system 1 according to the present embodiment. FIG. 1 shows a diagram of the battery system 1 as viewed from above. As shown in FIG. 1, the battery system 1 includes a junction box (hereinafter, referred to as J / B) 2, which is a control device, a first stack 10, a second stack 20, a third stack 30, and a fourth stack 40. The J / B 2 includes an ECU (Electronic Control Unit) 4. In the present embodiment, the battery system 1 includes four stacks arranged in a predetermined direction. Each stack includes a battery module configured of a predetermined number of secondary battery cells (not shown). The secondary battery may be a lithium ion battery or a nickel metal hydride battery. The battery system 1 is mounted as a power source in an electric vehicle such as an electric vehicle or a hybrid vehicle.

[0012] Furthermore, the first stack 10 to the fourth stack 40 are provided with a first monitoring unit 12, a second monitoring unit 22, a third monitoring unit 32, and a fourth monitoring unit 42, respectively. The first monitoring unit 12 acquires the battery state (voltage, current, and temperature) from various sensors (voltage sensor, current sensor, and temperature sensor) of the first stack 10 (not shown). The second monitoring unit 22 acquires the battery state, for example, from various sensors of the second stack 20. The third monitoring unit 32 acquires the battery state, for example, from various sensors of the third stack 30. The fourth monitoring unit 42 acquires the battery state, for example, from various sensors of the fourth stack 40. Each of the first monitoring unit 12 to the fourth monitoring unit 42 transmits the acquired information to the ECU 4.

[0013] In the present embodiment, the first monitoring unit 12 includes a monitoring IC (Integrated Circuit) 14 and a wireless IC 16. The second monitoring unit 22 includes a monitoring IC 24 and a wireless IC 26. The third monitoring unit 32 includes a monitoring IC 34 and a wireless IC 36. The fourth monitoring unit 42 includes a monitoring IC 44 and a wireless IC 46. For example, the monitoring IC 24 acquires battery information of the second stack 20 from various sensors of the second stack 20. The wireless IC 26 transmits the battery information from the monitoring IC 24 to the ECU 4. Note that the other monitoring ICs and wireless ICs have the same functions as the monitoring IC 24 and the wireless IC 26. Therefore, detailed description thereof will not be repeated.

[0014] The ECU 4 includes a main microcomputer 6 and a wireless IC 8. The wireless IC 8 is configured to be capable of wireless communication with each of the first monitoring unit 12, the second monitoring unit 22, the third monitoring unit 32, and the fourth monitoring unit 42. The main microcomputer 6 executes various control processes using battery information on the states of the first stack 10 to the fourth stack 40 received from the wireless IC 8. The various control processes include, for example, charging control, discharging control, and cooling control. The main microcomputer 6 includes, for example, a processor that executes a program such as a CPU (Central Processing Unit), and memories such as a ROM (Read Only Memory) and a RAM (Random Access Memory). The memories include control programs for executing the various control processes described above.

[0015] The ECU 4 and each monitoring unit (first monitoring unit 12 to fourth monitoring unit 42) have a star-shaped communication topology with the ECU 4 at the center. A WBMS (Wireless Battery Management System) is configured by enabling the ECU 4 and each monitoring unit to communicate with each other using wireless communication. By adopting the star topology, it is possible to suppress an increase in the number of wireless communication circuits and an increase in the amount of data per communication, compared to a case where a daisy-chain type communication topology is used. In particular, in a vehicle equipped with a large-capacity battery, such wireless communication reduces the use of harnesses, thereby improving the layout, improving energy density, and reducing costs. There is no particular limitation on the method of wireless communication between the ECU 4 and each monitoring unit, and any known technology may be used.

[0016] In the battery system 1 having the above-mentioned configuration, when each monitoring unit is provided on the top of each stack, the space in the height direction of the stack increases, and the energy density may decrease. Furthermore, when each monitoring unit is provided on the side of each stack, multiple monitoring units may be provided between adjacent stacks. As a result, the signal of the monitoring unit provided farther from the ECU 4 is blocked by the monitoring unit provided closer to the ECU 4, and the received signal strength at the ECU 40 may decrease, and the reliability of communication may decrease.

[0017] Therefore, in this embodiment, the first monitoring unit 12 and the second monitoring unit 22 are provided between the adjacent first stack 10 and second stack 20. The ECU 4 is provided at a position where there is no obstruction between the ECU 4 and the first monitoring unit 12. The second monitoring unit 22 is provided at a position where the distance to the ECU 4 is longer than that of the first monitoring unit 12. The second monitoring unit 22 and the ECU 4 are connected by a waveguide 21.

[0018] In this way, the first monitoring unit 12 is provided at a position where there is no obstruction between it and the ECU 4, and the second monitoring unit 22 communicates via the waveguide 21, ensuring reliability of communication with the ECU 4. Furthermore, the first monitoring unit 12 and the second monitoring unit 22 are provided between two adjacent stacks, which allows space saving and improved energy density.

[0019] The configuration of the battery system 1 according to the present embodiment will be described in more detail below. As shown in FIG. 1, a first monitoring unit 12 and a second monitoring unit 22 are provided in a space formed by the side surface of the first stack 10 and the side surface of the second stack 20 facing each other. The first monitoring unit 12 is provided on the side surface of the first stack 10, at a position where the distance to the J / B2 is relatively shorter than that of the second monitoring unit 22. The J / B2 is provided at a position where there is no obstruction between the first monitoring unit 12 and the second monitoring unit 22. The second monitoring unit 22 is provided on the side surface of the second stack 20, at a position where the distance to the ECU 4 is relatively longer than that of the first monitoring unit 12. The first monitoring unit 12 is provided on the side surface of the first stack 10 so as to be in a positional relationship where a part of the first monitoring unit 12 is not interposed in the space where the second monitoring unit 22 and the J / B2 face each other.

[0020] For example, the first monitoring unit 12 is provided on a side surface of the first stack 10, and the second monitoring unit 22 is provided on a side surface of the second stack 20 so that the first monitoring unit 12 and the second monitoring unit 22 are not overlapped when viewed in a direction parallel to the horizontal plane on which the stacks are arranged and from a direction (direction of arrow A) of viewing J / B2 through between the first stack 10 and the second stack 20. Furthermore, the second monitoring unit 22 and J / B2 are connected by a waveguide 21. The waveguide 21 has a predetermined shape, such as a rectangular, circular, or elliptical cross section, and has a hollow structure. The waveguide 21 has, for example, a rod-like shape without a bent portion. The waveguide 21 has, for example, a structure and material (metal, etc.) that easily propagates radio waves from the wireless IC 24 to J / B2.

[0021] Further, as shown in FIG. 1, a third monitoring unit 32 and a fourth monitoring unit 42 are provided in a space formed by the side surface of the third stack 30 and the side surface of the fourth stack 40 facing each other. The third monitoring unit 32 is provided on the side surface of the third stack 30 at a position that is relatively closer to the ECU 4 than the fourth monitoring unit 42. The fourth monitoring unit 42 is provided on the side surface of the fourth stack 40 at a position that is relatively longer to the J / B2 than the third monitoring unit 32. The third monitoring unit 32 is provided on the side surface of the third stack 30 so that a part of the third monitoring unit 32 is not interposed between the fourth monitoring unit 42 and the space facing the J / B2. The positional relationship between the third monitoring unit 32 and the fourth monitoring unit 42 is similar to the positional relationship between the first monitoring unit 12 and the second monitoring unit 22 described above, and therefore detailed description thereof will not be repeated.

[0022] Furthermore, the fourth monitoring unit 42 and J / B2 are connected by a waveguide 41. The waveguide 41 has a similar configuration to the waveguide 21. Therefore, detailed description thereof will not be repeated.

[0023] The operation of the battery system 1 having the above configuration will be described below. When various control processes are executed in the battery system 1, the first monitoring unit 12 to the fourth monitoring unit 42 acquire the battery status of each of the first stack 10 to the fourth stack 40 by various sensors during the execution of the various control processes, and transmit information indicating the acquired battery status to the ECU 4. At this time, the first monitoring unit 12 and the third monitoring unit 32 are located close to the ECU 4 and are not obstructed. Therefore, the generation of external noise, the generation of multipath fading due to interference of the radio waves with direct waves due to reflection, diffraction, etc., and the decrease in reliability of communication due to signal attenuation, etc. are suppressed.

[0024] Meanwhile, the second monitoring unit 22 and the fourth monitoring unit 42 transmit information indicating the battery states of the second stack 20 and the fourth stack 40 to the wireless IC 8 via the waveguide 21 and the waveguide 41, respectively, to the ECU 4 without being hindered by the first monitoring unit 12 and the third monitoring unit. This prevents the reliability of these communications from decreasing.

[0025] As described above, according to the battery system 1 of the present embodiment, the first monitoring unit 12 and the third monitoring unit 32 are provided at positions where there is no obstruction between them and the J / B 2, and therefore the deterioration of the reliability of the wireless communication with the ECU 4 can be suppressed. The second monitoring unit 22 and the fourth monitoring unit 42 communicate with the ECU 4 via the waveguides 21 and 41, and therefore the occurrence of multipath fading can be suppressed, and the deterioration of the reliability of the wireless communication with the ECU 4 can be suppressed. Furthermore, the first monitoring unit 12 and the second monitoring unit 22 are provided between the adjacent first stack 10 and second stack 20, and therefore space can be saved, and the energy density can be improved. Therefore, it is possible to provide a battery system that achieves both an improvement in energy density and a suppression of a deterioration in the reliability of communication.

[0026] Modifications will be described below.

[0027] In the above embodiment, the end of a monitoring unit provided on a side surface of one of two adjacent stacks on the side surface of the other stack is limited to half the length to the side surface of the other stack, so that the two monitoring units are provided at a position where they do not overlap in the left-right direction when viewed from the opposite side across the stacks from the position of J / B2 (arrow A) via the stacks. However, the position where the two monitoring units do not overlap in the space between the stacks is not particularly limited to the above-mentioned position. For example, the two monitoring units may be provided at a position where they do not overlap in the up-down direction.

[0028] Fig. 2 is a diagram showing an example of the configuration of a battery system 1 according to a modified example. The battery system 1 shown in Fig. 2 includes a first monitoring unit 12a, a second monitoring unit 22a, a third monitoring unit 32a, and a fourth monitoring unit 42a instead of the first monitoring unit 12 to the fourth monitoring unit 42 of the battery system 1 in Fig. 1, respectively.

[0029] The first monitoring unit 12a is provided on a side surface of the first stack 10, and is provided in the upper half of the space in the height direction between the first stack 10 and the second stack 20, as shown in the view from the arrow A in FIG. 1. The second monitoring unit 22a is provided on a side surface of the second stack 20, and is provided in the lower half of the space in the height direction between the stacks. The second monitoring unit 22a and J / B2 are connected by a rod-shaped waveguide 21a. The waveguide 21a has a similar structure and material as the waveguide 21, and detailed description thereof will not be repeated.

[0030] The third monitoring unit 32a, the fourth monitoring unit 42a, and the waveguide 41a have the same configuration as the first monitoring unit 12a, the second monitoring unit 22a, and the waveguide 21a, and therefore detailed description thereof will not be repeated.

[0031] Even in this case, the first monitoring unit 12a and the third monitoring unit 32a are provided at positions where there are no obstructions between them and the J / B 2, so that it is possible to suppress a decrease in the reliability of wireless communication with the ECU 4. The second monitoring unit 22a and the fourth monitoring unit 42a communicate with the ECU 4 via the waveguides 21a and 41a, so that it is possible to suppress the occurrence of multipath fading and to suppress a decrease in the reliability of wireless communication with the ECU 4. Furthermore, the first monitoring unit 12a and the second monitoring unit 22a are provided between adjacent stacks, so that it is possible to save space and improve energy density.

[0032] Furthermore, in the above-described embodiment, a battery system 1 having four stacks arranged in a row has been described as an example, but the number of stacks is not limited to four, nor is it limited to a row.

[0033] Fig. 3 is a diagram showing another example of the configuration of a battery system 1 according to a modified example. The battery system 1 shown in Fig. 3 is configured by adding a battery group in which a fifth stack 50, a sixth stack 60, a seventh stack 70, and an eighth stack 80 are arranged in a line to the battery group in which the first stack 10 to the fourth stack 40 in the above-mentioned embodiment are arranged in a line.

[0034] Furthermore, a fifth monitoring unit 52 and a sixth monitoring unit 62 are provided between the fifth stack 50 and the sixth stack 60. Furthermore, a seventh monitoring unit 72 and an eighth monitoring unit 82 are provided between the seventh stack 70 and the eighth stack 80. The fifth monitoring unit 52, the sixth monitoring unit 62, the seventh monitoring unit 72 and the eighth monitoring unit 82 are similar in position and function to the first monitoring unit 12 to the fourth monitoring unit 42 provided in the stacks corresponding thereto, and therefore detailed description thereof will not be repeated except as described below.

[0035] The fifth monitoring unit 52 is provided with a waveguide 51, one end of which is inserted into the space between the first stack 10 and the second stack 20 and the other end of which is coupled to the fifth monitoring unit 52. The waveguide 51 is connected at one end to the waveguide 21 via a connection portion 53. The sixth monitoring unit 62 is provided with a waveguide 61, one end of which is connected to the waveguide 51 via a connection portion 63 and the other end of which is coupled to the sixth monitoring unit 62.

[0036] The seventh monitoring unit 72 is provided with a waveguide 71, one end of which is inserted into the space between the third stack 30 and the fourth stack 40 and the other end of which is coupled to the seventh monitoring unit 72. One end of the waveguide 71 is connected to the waveguide 41 via a connection portion 73. The eighth monitoring unit 82 is provided with a waveguide 81, one end of which is connected to the waveguide 71 via a connection portion 83 and the other end of which is coupled to the eighth monitoring unit 82.

[0037] Even in such a configuration, the first monitoring unit 12 to the eighth monitoring unit 82 in the first row are all provided between the stacks, thereby saving space and improving energy efficiency. Furthermore, the use of the waveguides 21, 41, 51, 61, 71, and 81 can suppress a decrease in reliability of wireless communication between each monitoring unit and the ECU 4.

[0038] The above-described modified examples may be implemented in whole or in part in appropriate combination.

[0039] The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present invention is defined by the claims, not the above description, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0040] 1 battery system, 2 J / B, 4 ECU, 6 main microcontroller, 10, 20, 30, 40, 50, 60, 70, 80 stack, 12, 12a, 22, 22a, 32, 32a, 42, 42a, 52, 62, 72, 82 monitoring unit, 21, 21a, 41, 41a, 51, 61, 71, 81 waveguide, 53, 63, 73, 83 connection unit.

Claims

[Claim 1] A plurality of battery modules arranged in a predetermined direction; a plurality of monitoring devices provided in the plurality of battery modules, each of which monitors a battery state; a control device that wirelessly communicates with each of the plurality of monitoring devices; a first monitoring device and a second monitoring device corresponding to two adjacent battery modules among the plurality of battery modules are provided between the two adjacent battery modules; the control device is provided at a position where there is no obstruction between the control device and the first monitoring device, The second monitoring device is provided at a position that is farther from the control device than the first monitoring device, A battery system, wherein the second monitoring device and the control device are connected by a waveguide.

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