JP2010142083A - Battery pack system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a battery pack system capable of obtaining practical communication quality in transmission and reception of battery information, and securing the flexibility in an arrangement of battery cells. <P>SOLUTION: The system includes a battery pack 200 which has a first surface and a second surface facing the first surface, and has a plurality of battery cells 210 having electrodes on the first surface and connected in series, a capture circuit 130 for acquiring the battery information of each of the plurality of battery cells, a radio circuit 120 generating a radio signal including the battery information, a first antenna 110 which is attached on the second surface in any one of the plurality of battery cells, and transmits the radio signal, a second antenna 310 which receives the radio signal, and a management unit 320 which is connected to the second antenna 310, and reproduces and supervises the battery information based on the radio signal. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an assembled battery system that transmits battery information by wireless communication.

  In recent years, electric vehicles and hybrid vehicles have attracted attention from the viewpoint of reducing environmental impact. In-vehicle batteries that influence the running performance of electric vehicles and hybrid vehicles are required to have a high voltage of several tens of volts or more in order to drive the motor. As an in-vehicle battery, a so-called assembled battery in which a plurality of battery cells (about several tens) having an electromotive force of about 1 to 2 V are connected in series to obtain a high voltage may be used.

  In an assembled battery, voltage variation between battery cells becomes a problem. Since the battery cells are connected in series, the current flowing through each battery cell is common, but if the capacity (capacity) varies between the battery cells, the voltage varies. That is, the voltage may reach the upper limit voltage during charging (overcharge state), or the voltage may reach the lower limit voltage during discharge (overdischarge state). Both the overcharged state and the overdischarged state of the battery cell cause the performance deterioration of the assembled battery. Therefore, in the assembled battery system, a battery information acquisition circuit for acquiring battery information such as voltage and temperature of individual battery cells constituting the assembled battery is provided, and the battery information acquired by the battery information acquisition circuit is assembled. The data is transmitted to a management unit that controls the entire battery system. The management unit monitors the battery information, adjusts the voltage of the battery cell as necessary, and notifies the outside of the abnormality of the battery cell.

  One type of battery information transmission means is wired communication. That is, by connecting the battery information acquisition circuit and the management unit using, for example, a cable (harness), the battery information acquisition circuit can transmit the battery information to the management unit. However, when a wired connection is made between the management unit and the battery information acquisition circuit, the arrangement of the battery cells is restricted by the wiring of the cable.

Patent Document 1 describes a state monitoring device that transmits battery information by wireless communication. According to the state monitoring device described in Patent Document 1, a cable for transmitting battery information is not necessary, and thus it is easy to ensure a degree of freedom in the arrangement of battery cells.
JP 2005-135762 A

  Patent Document 1 does not disclose a specific configuration and arrangement of an antenna for realizing wireless communication between the battery information acquisition circuit and the management unit. More specifically, in Patent Document 1, in order to achieve communication quality that is practically required in the transmission and reception of battery information and to ensure flexibility in the arrangement of battery cells, the antenna and management of the battery information acquisition circuit It has not been considered how to configure and arrange the unit's antenna. If the communication quality required for practical use in the transmission / reception of battery information is not obtained, the management unit cannot sufficiently monitor the battery information of each battery cell and may overlook abnormalities such as overcharge and overdischarge. There is. On the other hand, if the degree of freedom in battery cell arrangement cannot be ensured, restrictions are imposed on the design of the assembled battery system.

  Therefore, an object of the present invention is to provide an assembled battery system that can obtain a practical communication quality in transmission / reception of battery information and can secure a degree of freedom in the arrangement of battery cells.

  An assembled battery system according to an aspect of the present invention is a set in which a plurality of battery cells each having a first surface and a second surface facing the first surface and having electrodes provided on the first surface are connected in series. A battery, an acquisition circuit that acquires battery information of each of the plurality of battery cells, a wireless circuit that generates a wireless signal including the battery information, and the second surface of any one of the plurality of battery cells A first antenna for transmitting the radio signal, a second antenna for receiving the radio signal, and connected to the second antenna, reproducing the battery information based on the radio signal and monitoring And a management unit.

  ADVANTAGE OF THE INVENTION According to this invention, practical communication quality is obtained in transmission / reception of battery information, and the assembled battery system which can ensure the freedom degree in arrangement | positioning of a battery cell can be provided.

Embodiments of the present invention will be described below with reference to the drawings.
(First embodiment)
As shown in FIG. 1, the assembled battery system according to the first embodiment of the present invention includes a battery information acquisition unit 100, an assembled battery 200, and a management device 300.

  The assembled battery 200 is configured by connecting a plurality of battery cells 210 in series in order to obtain a high voltage. The battery cell 210 is a secondary battery such as a lithium ion battery (LiB). The outer shape of the battery cell 210 is generally columnar, and an electrode is provided on one surface (hereinafter simply referred to as an electrode surface). Both ends of the assembled battery 200 are connected to external terminals for connection to an external device such as a motor. One end of the assembled battery 200 is connected to an external terminal via the management device 300. The assembled battery 200 may be configured by further connecting the battery cells 210 connected in series in parallel to obtain a large capacity.

  The battery information acquisition unit 100 includes an antenna 110, a radio circuit 120, and a battery information acquisition circuit 130. The battery information acquisition unit 100 may be provided for each battery cell 210 or may be provided for each battery cell group including a plurality of (for example, five) battery cells 210. The battery information acquisition unit 100 acquires battery information of the battery cell 210 according to the control signal received from the management device 300 and transmits the battery information to the management device 300.

  The antenna 110 inputs a radio signal received from the antenna 310 described later to the radio circuit 120 or transmits a radio signal input from the radio circuit 120 to the antenna 310. In this embodiment, it is assumed that the antenna 110 is an electromagnetic induction antenna that realizes wireless communication by coupling so-called induction magnetic fields.

  The radio circuit 120 performs a down-conversion process, an analog-digital conversion process, a demodulation process, a decoding process, and the like on the radio signal from the antenna 110 to reproduce the control signal. The radio circuit 120 determines whether or not the ID stored in the reproduced control signal matches the ID assigned to the radio circuit 120. If the two match, the radio information is sent to the battery information acquisition circuit 130. Request. The radio circuit 120 adds the ID of the radio circuit 120 to the battery information input from the battery information acquisition circuit 130, and then performs encoding processing, modulation processing, digital-analog conversion processing, up-conversion processing, and the like. To generate a radio signal and input it to the antenna 110.

  When battery information is requested from the wireless circuit 120, the battery information acquisition circuit 130 measures the voltage generated at both ends of the battery cell 210 to be measured, the temperature of the battery cell 210, and the like to generate battery information. The battery information acquisition circuit 130 inputs the generated battery information to the wireless circuit 120.

  The management device 300 includes an antenna 310 and a management unit 320. The management device 300 periodically monitors battery information of each of the plurality of battery cells 210 constituting the assembled battery 200 and notifies the outside if there is an abnormality.

  The antenna 310 transmits a radio signal input from the management unit 320 to the antenna 110 and inputs a radio signal received from the antenna 110 to the management unit 320. In the present embodiment, the antenna 310 is an electromagnetic induction antenna.

  The management unit 320 generates a control signal storing an ID assigned to the wireless circuit 120 inside the battery information acquisition unit 100 connected to the battery cell 210 to be monitored in order to realize monitoring of the battery information. . Further, the management unit 320 performs a coding process, a modulation process, a digital-analog conversion process, an up-conversion process, etc. on the control signal to generate a radio signal and inputs it to the antenna 310.

  In addition, the management unit 320 performs down-conversion processing, analog-digital conversion processing, demodulation processing, decoding processing, and the like on the radio signal input from the antenna 310 to reproduce the battery information of the battery cell 210 to be monitored. . The management unit 320 checks whether there is an abnormality in the battery cell 210 connected to the battery information acquisition unit 100 including the wireless circuit 120 identified by the ID added to the battery information. If there is an abnormality in the battery information, the management unit 320 attempts to eliminate the abnormality or outputs a signal for notifying the abnormality to the outside.

  Usually, in order to simplify the wiring between the battery cells 210 and to make the assembled battery 200 compact, it is desirable to arrange the battery cells 210 close to each other. For example, as shown in FIG. 2, the battery cells 210 are stacked and arranged in a matrix with the electrode surfaces directed in the same direction. According to the battery cell arrangement of FIG. 2, the assembled battery system can be configured in a compact manner, and the wiring between the battery cells 210 can be simplified.

  Hereinafter, the mounting position of the antenna 110 will be considered. In the case where the battery cell 210 is arranged as shown in FIG. 2, for example, it is assumed that the antenna 110 is attached to the side surface of the battery cell 210 (that is, a surface perpendicular to the electrode surface). At this time, the antenna 110 needs to perform wireless communication using a small space generated between adjacent columns in a matrix in which a plurality of battery cells 210 are stacked (hereinafter simply referred to as an arrangement matrix). The communication with the antenna 310 tends to be out-of-line communication. In addition, since the antenna 110 is attached close to the electrode of the battery cell 210 that is a conductor, the impedance changes, and high radiation efficiency cannot be obtained. Therefore, the communication quality between the antenna 110 and the antenna 310 may be less than that required for practical use. If the antenna 110 is attached to the side surface of the battery cell 210 to improve the communication quality, for example, the arrangement matrix must be configured in one row or a plurality of antennas 310 must be provided. Restrictions are imposed on the design of

  Therefore, as shown in FIG. 3, in the assembled battery system according to the present embodiment, the antenna 110 is attached to a surface facing the electrode surface of the battery cell 210 (hereinafter simply referred to as an antenna surface). 3 illustrates the case where the antennas 110 are attached to the antenna surfaces of all the battery cells 210. However, when the battery information acquisition unit 100 is provided for each battery cell group including a plurality of battery cells 210. The antenna 110 may be attached to the antenna surface of one battery cell 210 belonging to each of the battery cell groups. As shown in FIG. 3, when the antenna 110 is attached to the antenna surface of the battery cell 210 that is arranged in a matrix with the electrode surfaces facing in the same direction, the antenna 310 of the management device 300 communicates wirelessly with the antenna 110. It is arranged through the space for. More specifically, since the antenna 110 and the antenna 310 are electromagnetic induction type antennas, the antenna 310 is arranged so as to be linked to the magnetic field generated from the antenna 110. In the antenna arrangement of FIG. 3, since there is no obstacle between the antenna 110 and the antenna 310, communication between the two becomes line-of-sight communication, achieving communication quality that is practically required for transmission / reception of battery information. Cheap. Further, in the antenna arrangement of FIG. 3, the number of rows and the number of columns of the arrangement matrix have little influence on the communication quality. That is, according to the antenna arrangement of FIG. 3, the battery cell 210 can be freely arranged while achieving the communication quality that is practically required in the transmission and reception of battery information.

  When the number of battery cells 210 is enormous, a plurality of sets of battery cells 210 arranged close to each other may be prepared. For example, as shown in FIG. 4, when two sets of battery cells 210 arranged close to each other are prepared, the battery cells 210 in each set are matrixes with the electrode surfaces facing in the same direction as described above. Are arranged in a stack. Each set is arranged so that the antenna surfaces of the battery cells 210 constituting the set face each other with a gap 400 therebetween. In the gap 400, the antenna 310 is disposed and used as a space for wireless communication with the antenna 110, and also serves as a heat radiation space for each battery cell 210.

  In general, when a thermal runaway due to heating occurs in the battery cell 210 made of LiB or the like, the temperature and pressure in the housing of the battery cell 210 rapidly increase, which may cause an accident such as heat generation, ignition, or explosion. Therefore, in order to use the battery cell 210 safely, it is desirable that some heat dissipation means be taken. In the battery cell arrangement of FIG. 4, heat generated by the battery cell 210 is dissipated through a medium (for example, air or artificial medium) accommodated in the gap 400. Further, an electromagnetic wave that realizes communication between the antenna 110 and the antenna 310 is also propagated through the medium. That is, the battery cell arrangement of FIG. 4 can also use the heat radiation space necessary for practical use of the battery cell 210 as a space for wireless communication, so that the assembled battery system can be configured compactly.

  Further, as shown in FIG. 5, it is desirable that the antenna 110 be attached substantially parallel to the antenna surface of the battery cell 210 with a predetermined distance d. The predetermined interval d is an interval at which the induced magnetic field can be sufficiently linked at the operating frequency of the antenna 110 and the antenna 310. Further, the predetermined distance d can be shortened by inserting a magnetic material (that is, a paramagnetic material) having a permeability larger than 1 between the antenna surface of the battery cell and the antenna.

  As described above, in the assembled battery system according to this embodiment, an antenna is attached to the surface facing the surface on which the electrode of the battery cell is provided, and wireless communication is performed with the antenna of the management device. Therefore, according to the assembled battery system according to the present embodiment, practical communication quality can be obtained in the transmission and reception of battery information, and battery cells can be freely arranged.

(Second Embodiment)
The assembled battery system according to the first embodiment described above is configured using an electromagnetic induction antenna. On the other hand, the assembled battery system according to the second embodiment of the present invention is configured using a radio wave type antenna that realizes wireless communication by coupling radiation fields.

When a patch antenna or a slot antenna that uses the ground is used as the radio wave antenna 110, for example, as shown in FIG. 6, the metal surface 500 constituting at least a part of the antenna surface of the battery cell 210 is used as the ground. Available.
In addition, when an antenna designed to radiate in free space such as a dipole antenna is used as the radio wave antenna 110, as shown in FIG. 7, the radio wave antenna 110 and a metal surface 500 as a ground are interposed. A high impedance surface 600 may be provided. The high-impedance surface 600 suppresses the reverse-phase current flowing on the ground, so that the antenna 110 can be easily lowered. That is, by providing the high impedance surface 600, the assembled battery system can be configured more compactly.

  The surface impedance of the high impedance surface 600 is higher than the free space impedance, and is ideally infinite. The high impedance surface 600 is made of a magnetic material (that is, a paramagnetic material) having a magnetic permeability greater than 1, or an artificial medium that can amplify the surface impedance to infinite by antiresonance based on a periodic structure.

  For example, the high impedance surface 600 can be formed of a so-called EBG (Electromagnetic Band Gap) substrate. The EBG substrate is a distributed constant circuit configured by arranging small plate-shaped conductor elements in a matrix at predetermined intervals above a metal plate (ground). A linear element connects between the metal plate and each of the conductor elements arranged in a matrix.

  Specifically, as shown in FIG. 8, the EBG substrate includes a plurality of metal patches 601 arranged in a matrix at a predetermined interval above the metal surface 500, a metal surface 500, and a plurality of metal patches 601. And a via 603 that penetrates the dielectric 602 and connects between the metal surface 500 and the substantially central portion of each of the plurality of metal patches 601. The metal patch 601 is made of, for example, small plate-shaped copper. The dielectric 602 is made of, for example, polytetrafluoroethylene.

  FIG. 9 shows a cross-sectional view taken along line AA in FIG. As shown in FIG. 9, a plurality of metal patches 601 are arranged above the metal surface 500 with vias 603 in a state with a slight gap therebetween. A dielectric 602 is filled between the metal patches 601 adjacent to each other. That is, as shown in FIG. 10, a portion between an end portion of a certain metal patch 601 and an end portion of the metal patch 601 adjacent to the metal patch 601 functions as an equivalent circuit of a capacitor. In addition, there is a path through the via 603 and the metal surface 500 between an end of a certain metal patch 601 and an end of the metal patch 601 adjacent to the metal patch 601, and the path is an equivalent circuit of an inductor. Function as. That is, it can be considered that the metal patches 601 adjacent to each other on the EBG substrate are connected via a parallel circuit of a capacitor and an inductor (that is, an LC resonator).

  That is, the EBG substrate has a frequency band that causes anti-resonance in a direction parallel to the metal surface 500 (hereinafter simply referred to as anti-resonance frequency). The impedance of the EBG substrate is extremely increased with respect to the signal of the anti-resonance frequency, and the reflection phase becomes a value close to 0 degrees. Therefore, by configuring the EBG substrate as the high impedance surface 600 so that the anti-resonance frequency becomes a value close to the operating frequency of the antenna 110, the antenna 110 can be lowered.

  Further, the assembled battery system according to the present embodiment may be configured to be housed in a shield case 700 as shown in FIG. The shield case 700 confines radio waves radiated from the antenna 110 and the antenna 310 inside. Specifically, if the shield case 700 is made of a conductor, the thickness may be set to half or less of the wavelength λ of free space. According to the shield case 700, efficient wireless communication can be realized, and unnecessary radiation to the outside can be suppressed.

  Further, when the antenna 310 is accommodated in the shield case 700, the antenna 310 may be attached to the surface of the shield case 700. At this time, due to the influence of the metal wall on the side surface of the shield case, a standing wave is generated in the shield case, and the antenna 310 at the node of the standing wave does not receive radio waves. It is desirable to adhere a radio wave absorber to the surface of the shield case 700 so that (Transverse Electro Magnetic) waves can propagate. When an antenna using a ground as described in FIG. 6 is used as the antenna 310, it is desirable to attach a radio wave absorber to the surface excluding the portion where the antenna 310 is attached, and attach the antenna directly to the shield case. On the other hand, when an antenna designed to radiate in free space as described in FIG. 7 is used as the antenna 310, a radio wave absorber is provided between the antenna 310 and the shield case 700. That is, a radio wave absorber is bonded to the inner surface of the shield case 700, and the antenna 310 is attached to the surface of the radio wave absorber. In this way, if a TEM wave is received via the radio wave absorber, communication between the antenna 110 and the antenna 310 is further facilitated, and the battery cell 210 can be arranged more freely.

  As described above, the assembled battery system according to the present embodiment replaces the electromagnetic induction type antenna with the radio wave type antenna in the assembled battery system according to the first embodiment described above. Also by the assembled battery system according to the present embodiment, the same effect as that of the assembled battery system according to the first embodiment described above can be obtained.

  Note that the present invention is not limited to the above-described embodiments as they are, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. Various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the above embodiments. Further, for example, a configuration in which some components are deleted from all the components shown in each embodiment is also conceivable. Furthermore, you may combine suitably the component described in different embodiment.

The block diagram which shows the assembled battery system which concerns on 1st Embodiment. The figure which shows the example of arrangement | positioning of the battery cell of FIG. The figure which shows the example of arrangement | positioning of the antenna of FIG. The figure which shows the example of arrangement | positioning of the battery cell of FIG. The figure which shows the example of attachment of the antenna to the antenna surface of the battery cell of FIG. The figure which shows an example of the antenna in the assembled battery system which concerns on 2nd Embodiment. The figure which shows an example of the antenna in the assembled battery system which concerns on 2nd Embodiment. The figure which shows an example of the high impedance surface of FIG. Sectional drawing of the AA line in FIG. The enlarged view of the dotted-line area | region in FIG. The figure which shows the example of arrangement | positioning of the antenna in the assembled battery system which concerns on 2nd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 ... Battery information acquisition part 110 ... Antenna 120 ... Radio circuit 130 ... Battery information acquisition circuit 200 ... Battery assembly 210 ... Battery cell 300 ... Management apparatus 310 ... Antenna 320 ... Management unit 400 ... Gap 500 ... Metal surface 600 ... High impedance surface 601 ... Metal patch 602 ... Dielectric 603 ... Via 700 ... Shield case

Claims (10)

An assembled battery in which a plurality of battery cells having a first surface and a second surface opposite to the first surface and having electrodes on the first surface are connected in series;
An acquisition circuit for acquiring battery information of each of the plurality of battery cells;
A radio circuit for generating a radio signal including the battery information;
A first antenna attached to any one of the plurality of battery cells and transmitting the radio signal;
A second antenna for receiving the radio signal;
A battery pack system comprising: a management unit connected to the second antenna and reproducing and monitoring the battery information based on the radio signal.   2. The assembled battery system according to claim 1, wherein the assembled battery includes two battery cells arranged with a gap so that the second surface faces each other.   The assembled battery system according to claim 2, further comprising an artificial medium disposed between the second surfaces facing each other.   2. The first antenna is attached to the second surface with a sufficient interval for an induced magnetic field to interlink, and transmits and receives the radio signal by coupling the induced magnetic field. The assembled battery system described. At least a portion of the second surface is a metal surface;
2. The assembled battery system according to claim 1, wherein the first antenna transmits and receives the radio signal by coupling of a radiation field using the metal surface as a ground.   The assembled battery system according to claim 5, further comprising a high impedance surface between the metal surface and the first antenna.   The assembled battery system according to claim 6, wherein the high impedance surface is formed of an EBG substrate.   The assembled battery system according to claim 6, wherein the high impedance surface is made of a paramagnetic material.   The battery pack further includes a shield case that accommodates the assembled battery, the acquisition circuit, the wireless circuit, the first antenna, the second antenna, and the management unit and suppresses unnecessary radiation to the outside. The assembled battery system according to claim 5.   The assembled battery system according to claim 8, wherein the second antenna and the radio wave absorber are arranged on an inner surface of the shield case.

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