JP2016095174A - Battery control device and secondary battery system using battery control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a battery control device capable of reducing a stress and a strain applied to a connecting part between a shunt resistance and a battery control board without increasing the area of the connecting part and capable of improving accuracy of information to be obtained.SOLUTION: To solve the problem, a battery control device of the present invention has a battery control board which is connected to a battery and on which a detection unit detecting a voltage is disposed; and a shunt resistance in which a current of the battery flows and which is connected to the battery control board, the shunt resistance having a mechanical fixed part connected to the battery control board and a detection terminal connected to the battery control board.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a battery control device and a secondary battery system using the same.

  Currently, as global environmental problems are greatly highlighted, in order to prevent global warming, there is a need to reduce carbon dioxide emissions in every situation. About gasoline engine cars, which are a major source of carbon dioxide emissions. Has begun to be replaced by hybrid electric vehicles and electric vehicles.

  Large secondary batteries represented by power sources for hybrid electric vehicles and electric vehicles need to have high output and large capacity. Configure.

  Lithium ion batteries, which are secondary batteries, require appropriate use of secondary batteries, such as prevention of high voltage charging and deterioration of performance due to overdischarge. For this reason, a secondary battery system mounted on a hybrid electric vehicle or an electric vehicle includes a battery control device that detects voltage, current, temperature, and the like, which are battery states.

  FIG. 1 shows a configuration of a secondary battery system 800 mounted on a hybrid electric vehicle or an electric vehicle. As shown in this figure, a battery group 11 composed of one or more single cells 10 is connected to a battery control device 850, and the battery control device 850 is composed of one or more single cells 10. 11 states are detected. Further, a battery capacity (SOC: State of Charge) and a battery deterioration state (SOH: State of Health) are calculated from the battery information, and the calculation result is notified to the vehicle controller 810 and the like. The vehicle controller controls the inverter 830 connected via the relay box and the motor 840 connected to the inverter 830 based on the calculation result.

  The battery group 11 is connected in series with a current sensor (such as a shunt resistor) for detecting the current flowing through the battery group 11 (not shown in FIG. 1). This current sensor is arranged on a battery control board on which a microcomputer or the like is mounted. In particular, the information obtained from the current sensor is used to calculate the SOC and SOH of the battery, and therefore needs to be accurate.

  2A is a top view in the vicinity of the shunt resistor 100 described in Patent Document 1, and FIG. 2B is a cross-sectional view taken along the line AA in FIG. Patent Document 1 discloses a configuration in which a shunt resistor detection terminal 150 for detecting a current flowing through a battery is fixed to the battery control board 200 at four locations, as shown in FIG. With this configuration, the distance between the shunt resistor and the battery control board can be minimized, so that noise generated by energization can be reduced. Therefore, the information obtained from the current sensor becomes more accurate.

JP-T-2003-513596

  When the battery and the shunt resistor are connected by a bus bar or harness as in the invention described in Patent Document 1, the bus bar or harness is connected to the end of the shunt resistor. Therefore, stress is applied to the connection portion between the battery and the shunt resistor due to the weight of the bus bar and the harness, and torque and distortion are generated in the connection portion between the shunt resistor and the battery control board. When torque or distortion occurs at the connection between the shunt resistor and the battery control board, noise may be added to the information obtained from the current sensor, and the accuracy of the obtained information may be reduced.

  On the other hand, if the area of the connection portion between the shunt resistor and the battery control board is increased in order to reduce this distortion, the effect of reducing current noise is reduced, resulting in a problem that the accuracy of information obtained is lowered.

  Based on the above problems, the present invention provides a battery control device that reduces the stress and strain applied to the connecting portion without increasing the area of the connecting portion between the shunt resistor and the battery control board, and improves the accuracy of the obtained information. The purpose is to provide.

  In order to solve the above problems, the battery control device of the present invention has the following configuration.

  A battery control device used by being connected to a battery group including one or a plurality of single cells, wherein the battery control device includes a battery control board on which a detection unit for detecting a voltage is disposed, and the battery group A shunt resistor connected to the battery control board, and a shunt resistor having a machine fixing part connected to the battery control board and a detection terminal connected to the battery control board. A battery control device.

  By using the present invention, when a torque is applied between the bus bar and the shunt resistance element, the stress applied to the detection terminal can be reduced, and noise can be suppressed due to a decrease in bonding strength between the substrate and the shunt resistance.

Schematic of a battery system. (A) is a top view of the shunt resistance vicinity of patent document 1, (b) is AA sectional drawing of (a). The figure which shows the structure of a battery group and the battery control apparatus connected to it. The figure which shows a part of structure of a secondary battery system. The figure which shows the outline of the vicinity of the shunt resistance 100. FIG. (A)-(e) is a figure explaining the procedure until it fixes the battery control board 200 to the shunt resistance 100 using FIG. The 1st modification of 1st embodiment. The 2nd modification of 1st embodiment. The 3rd modification of 1st embodiment. (A) is a top view of the periphery of the battery control board according to the second embodiment, and (b) is a cross-sectional view taken along line AA of (a). (A) is a top view of the periphery of the battery control board of the modification of the second embodiment, (b) is a cross-sectional view taken along line AA of (a).

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that in all the drawings for explaining the embodiments, the same members are denoted by the same reference numerals, and the repeated explanation thereof is omitted.

<First embodiment>
The configuration of the battery control device 850 according to the embodiment of the present invention will be described below.

  FIG. 3 shows the structure of the battery group 11 and the battery control device 850 connected thereto. The battery control device 850 includes a cell voltage detection unit 20 that detects a cell voltage of each unit cell 10, a total voltage detection unit 30 that detects a voltage of the battery group 11, a shunt resistor 100 that detects a current flowing through the battery group 11, and a shunt. The battery state is estimated based on information obtained by the current detection unit 40 that detects the current flowing through the resistor 100, the cell voltage detection unit 20, the total voltage detection unit 30, and the current detection unit 40, and the vehicle controller 810 It has the microcomputer 50 which outputs information. The shunt resistor 100 is connected in series with the battery group 11 so that the current flowing through the battery group 11 can be detected.

  The battery control device 850 does not include the battery group 11.

  The cell voltage detection unit 20, the total voltage detection unit 30, the current detection unit 40, the microcomputer 50, and a part of the shunt resistor 100 are arranged on one battery control board 200.

  FIG. 4 shows a part of a configuration example of a secondary battery system 800 using the battery control device 850 of this embodiment. The secondary battery system 800 includes a battery group 11 having one or a plurality of unit cells 10, a shunt resistor 100, a battery control board 200 attached to the shunt resistor 100, and a casing 300 that covers these.

  The battery group 11 includes a plurality of unit cells 10 connected in series, and each unit cell 10 is connected via a bus bar 400. A part of the unit cell 10 is connected to the shunt resistor 100 by the bus bar 400. At this time, the connection direction of the cells 10 and the longitudinal direction of the shunt resistor 100 are perpendicular to each other.

  The unit cell 10 can be applied to any case where a fuel cell or a capacitor is mounted or a combination thereof, in addition to a secondary battery such as a lithium ion secondary battery or a nickel metal hydride battery. Moreover, although the example which connected shunt resistance with the bus bar is shown in this embodiment, you may connect with any of a harness, a cable, and a connector. FIG. 4 shows a battery group 11 using a plurality of unit cells 10, but a battery group 11 composed of one unit cell 10 may be used.

  In this specification, the battery group 11 is defined as including one or a plurality of unit cells 10.

  FIG. 5 schematically shows the vicinity of the shunt resistor 100. The shunt resistor 100 includes a battery connection part 110 connected to the unit cell 10 via the bus bar 400, a case connection part 120 connected to the case 300, a machine fixing part 130 mechanically connected to the battery control board 200, and a battery control. There are four detection terminals 150 electrically connected to the substrate 200 by solder 140. In this figure, an example is shown in which a base 310 and a cover 320 are provided as the housing 300 and the shunt resistor 100 is connected to both of them, but the shunt resistor may be fixed only by either the base or the cover.

  In FIG. 5, the shunt resistor 100 and the housing 300, and the shunt resistor 100 and the battery control board 200 are all fixed by screws, but another connection method such as welding may be used. The shunt resistor 100, the bus bar 400, and the harness may be integrated.

  A shearing force may act between the battery control board 200 and the shunt resistor 100 when the bus bar 400 and the shunt resistor 100 are connected or due to vibration during use. In the present invention, the connection between the battery control board 200 and the shunt resistor 100 is performed not only by the detection terminal 150 but also by the machine fixing unit 130. Therefore, when the shunt resistor 100 is attached to the bus bar 400, the force generated by vibration during use or the like can be received not by the detection terminal 150 but by the machine fixing portion 130, and the detection terminal 150 and the battery control board can be received. It is possible to prevent cracking and peeling of the solder 140 connecting the 200. Therefore, noise and the like due to poor connection of the detection terminal 150 can be prevented during current detection, and the current value can be detected with high accuracy.

  In the present invention, the machine fixing portion 130 is closer to the battery connection portion 110 than the detection terminal 150. In other words, the mechanical fixing unit 130 is disposed between the detection terminal 150 and the battery connection unit 110. With such a configuration, when a large torque is applied to the battery connection portion 110, the force can be reliably received by the machine fixing portion 130 before a force is applied to the solder 140 of the detection terminal 150. Therefore, cracking and peeling of the solder 140 can be further prevented.

  In the present invention, the diameter of the machine fixing portion 130 is larger than the diameter of the detection terminal 150. Therefore, when a large torque or force is applied to the battery connection portion 110, the force can be reliably received by the machine fixing portion 130 before the force is received by the solder 140 of the detection terminal 150. Furthermore, by increasing the diameter of the machine fixing part 130, the strength of the machine fixing part 130 is also increased. Therefore, it becomes a structure which can prevent the crack and peeling of the solder 140 more.

  Next, a procedure until the battery control board 200 is fixed to the shunt resistor 100 will be described with reference to FIG. First, as shown in FIG. 6A, components corresponding to the current detection unit 40, the cell voltage detection unit 20 (not shown in the figure), and the total voltage detection unit 30 (not shown in the figure) on the battery control board 200. Is implemented. Next, as shown in FIG. 6B, the battery control board 200 mounted with the component and the shunt resistor 100 are connected to each other by screwing at the machine fixing portion 130. In this state, the positions of the shunt resistor 100 and the battery control board 200 are fixed. Then, as shown in FIG. 6C, the detection terminal 150 provided on the shunt resistor 100 and the battery control board 200 are locally connected by solder 140. The battery control board 200 and the shunt resistor 100 are connected by such a procedure. Subsequently, as shown in FIG. 6 (d), the cover 320 and the base 310 are fixed to the shunt resistor 100 by the housing connecting part 120, and the housing 300 is formed. Finally, as shown in FIG. 6 (e), the bus bar 400 is connected to the shunt resistor 100 via the battery connection part 110. In this way, the battery control board 200 is provided on the shunt resistor 100 and the casing 300 is further formed.

  As described above, the battery control board 200 and the shunt resistor 100 are connected to each other at the two positions of the machine fixing portion 130 and the detection terminal 150 by screwing, so that it is not necessary to leave the mechanical fixing role to the detection terminal 150. Therefore, since the diameter of the detection terminal 150 can be reduced, current noise can be reduced. Further, since the detection terminal 150 has a small diameter and can be electrically connected by local soldering, the shunt resistor 100 is connected to the battery control board 200 without applying thermal stress to components on the battery control board 200. it can.

  Further, according to the configuration of the present embodiment, since the housing connection part 120 is disposed between the machine fixing part 130 and the battery connection part 110, there is an effect that it is easy to assemble. That is, since the housing connection part 120 is arranged in this way, as shown in the procedure of FIG. 6, the battery control board 200 and the shunt resistor 100 are connected and fixed and then installed in the housing 300. It becomes possible.

  Then, the 1st modification of this embodiment is shown in FIG. FIG. 7 is a diagram showing the battery control device 850 when only the battery control board 200 and the bus bar 400 are connected to the shunt resistor 100 without connecting the housing 300 to the shunt resistor 100. At this time, when a force F is applied to the bus bar in the direction of the arrow, the shunt resistor 100 is deformed to protrude downward in FIG. For this reason, there is a risk that stress is applied to the thin detection terminal 150 and the joint of the solder 140 of the detection terminal 150 is broken.

  In this modification, even if the housing 300 is not provided, the shunt resistor 100 is fixed by the machine fixing portion 130, so that the stress applied to the detection terminal 150 can be reduced, and the solder 140 of the detection terminal 150 can be joined. Breakage can be suppressed.

  In addition, this is not limited to the modified example, but in this embodiment, the machine fixing unit 130 includes a head 130a that is in close contact with the battery control board 200 and a fixing unit 130b that is in close contact with the shunt resistor 100. Since the battery control board 200 and the shunt resistor 100 are sandwiched between the head portion 130a and the fixing portion 130b, the warpage of the shunt resistor 100 is stopped by the mechanical fixing portion 130. Therefore, it is possible to further suppress the breakage of the joint portion of the solder 140 of the detection terminal 150. It is most preferable that the fixed portion 130b has a structure that is in close contact with the shunt resistor 100. However, as long as the warpage of the shunt resistor 100 can be regulated, there is no problem even if it is slightly separated from the surface of the shunt resistor 100.

  Then, the 2nd modification of this embodiment is demonstrated. In the second modification, the structure of the battery control board has a convex shape, and the detection terminal 150 and the machine fixing portion 130 are provided on the convex portion.

  FIG. 8 is a diagram showing a part of the secondary battery system using the battery control device 850 according to the second modification of the present embodiment. The embodiment is characterized in that a protrusion 210a is provided on a part of the battery control board 210 as described above.

  The detection terminal 150 of the shunt resistor 100 and the machine fixing part 130 are arranged on the convex part 210a. Similar to FIG. 4, the shunt resistor, the battery control board, and the battery are arranged, and the connection direction between the batteries and the longitudinal direction of the shunt resistor are perpendicular to each other. However, in this modification, the shunt resistance is smaller than the battery. For this reason, the convex part 210a is provided in the battery control board 210, and the shunt resistor 100 is arranged on the convex part 210a. With this structure, the battery control device 850 can be assembled even when the size of the battery is significantly different from the shunt resistance.

  In addition, the shape of the convex part 210a is not limited to the shape of FIG. 8, For example, it may be L-shaped as shown in FIG. Or the shape which provided the convex part 210a in the hexagonal or circular battery control board 200 may be sufficient. Even if it is these shapes, said effect can be acquired.

  Then, the 3rd modification of this embodiment is demonstrated. In the third modification, the battery control board 200 is disposed on the side surface of the unit cell 10.

  FIG. 9 is a diagram showing a part of a secondary battery system according to a third modification of the present embodiment. The unit cell 10 of this modification has a cubic shape or a rectangular parallelepiped shape, and has a top surface 10a, a bottom surface 10b, a top surface 10a, and a side surface 10c connected to the bottom surface 10b. In this modification, the battery control board 200 is not protruded from the upper surface of the unit cell 10, but the battery control board 200 is bonded to the side surface 10c of the unit cell 10. By adopting such a structure, it is not necessary to arrange the battery control board 200 so as to protrude from the unit cell 10, so that the shunt resistor 100 can be arranged in a compact manner without providing an extra space.

  In this modification, the battery connecting portion 110 of the shunt resistor 100 is inclined by 90 ° between the battery connecting portion of the shunt resistor and the housing connecting portion so as to be directly connected to the terminal of the unit cell 10. The secondary battery system can be created.

<Second Embodiment>
Next, the battery control device 850 of the second embodiment will be described. This embodiment is different from the first embodiment in that the cell voltage detection unit 20, the total voltage detection unit 30, and the microcomputer 50 are covered with a magnetic shielding plate 500. In addition, about the structure similar to 1st embodiment, the drawing number similar to the drawing number used in 1st embodiment is used.

  FIG. 10A is a view of the periphery of the battery control board 200 according to the present embodiment as viewed from above. The connection between the shunt resistor 100 and the battery control board 200 and the connection between the shunt resistor 100 and the housing 300 are not particularly different from the first embodiment. However, in the present embodiment, the cell voltage detection unit 20, the total voltage detection unit 30, and the microcomputer 50 are configured to be covered with the magnetic shielding plate 500. When the shunt resistor 100 is energized, a magnetic field is generated around the shunt resistor 100, the cell voltage detector 20 mounted on the battery control board 200, the total voltage detector 30 for measuring the total voltage of the battery group 11, and the total voltage. There is a possibility that the microcomputer 50 that estimates the state of the battery based on the information obtained by the detection unit 30 may be adversely affected. In particular, since the cell voltage detector 20 needs to observe the voltage in units of several mV, it is considered that the voltage error due to the influence of the magnetic field generated from the shunt resistor 100 becomes very large. In this embodiment, in order to avoid the influence of the magnetic field, the magnetic shielding plate 500 is provided so as to cover the cell voltage detection unit 20, the total voltage detection unit 30, and the microcomputer 50.

  FIG. 10B shows a cross-sectional view taken along the line AA in FIG. As illustrated in FIG. 10B, the magnetic shielding plate 500 has a structure that is disposed on the outer periphery of the housing 300. For example, the magnetic shielding plate 500 is fixed by connecting the protruding portion 500 a of the magnetic shielding plate 500 to a partition plate 300 a provided in the housing 300. In the case of this structure, the cell voltage detection unit 20, the total voltage detection unit 30, and the microcomputer 50 are housed in a closed space formed by the casing 300 and the partition plate 300a, and further, a magnetic shielding plate so as to cover the closed space. 500 is arranged. For this reason, the magnetic field can be shielded in a double manner, and the influence of the magnetic field on the sensor can be further reduced.

  A material having a magnetic susceptibility (χ) of 10 or more is used for the magnetic shielding plate 500. In the present specification, a material having a magnetic susceptibility χ of 10 or more is called a magnetic body. A material having a magnetic susceptibility χ has a relative permeability μr = (χ + 1). That is, a material (magnetic material) having a magnetic susceptibility of 10 or more has a property that it can easily pass a magnetic flux 11 times or more compared to air or a non-magnetic material. For this reason, the above effect can be obtained by using a material having a magnetic susceptibility of 10 or more as the magnetic shielding plate 500.

  As a material of the magnetic shielding plate 500, for example, iron (χ = 5000), silicon steel (χ = 7000), permalloy (χ = 40000 to 100,000), mu metal (χ = 100000) or the like may be used. In this embodiment, iron that is inexpensive and easy to manufacture is used.

  It is also possible to install the magnetic shielding plate as an integral part of the housing. FIG. 11A is a top view of a peripheral view of the battery control board 200 when the magnetic shielding plate 500 and the casing 300 are installed as an integrated body (modified example of FIG. 10). The magnetic shielding plate 500 is different from the structure of FIG. 10 in that the magnetic shielding plate 500 is integrated with the housing 300 and arranged on the inner side of the housing 300. Similarly to FIG. 10, the cell voltage detection unit 20, the total voltage detection unit 30, and the microcomputer 50 block the influence of magnetism from the shunt resistor with the magnetic shielding plate 500 integrated with the housing 300.

  FIG.11 (b) is AA sectional drawing of the figure shown to Fig.11 (a). As shown in FIG. 11B, the magnetic shielding plate 500 is integrated inside the housing 300 and covers the cell voltage detection unit 20, the total voltage detection unit 30, and the microcomputer 50. The magnetic shielding plate 500 has a protrusion 500a, and the tip of the protrusion 500a is disposed so as to contact the battery control board 200. By adopting such an arrangement, that is, an arrangement in which the cell voltage detection unit 20, the total voltage detection unit 30, and the microcomputer 50 are housed in a closed space formed by the battery control board 200 and the magnetic shielding plate 500, the magnetic shielding plate 500 It is possible to reliably suppress the influence of the magnetic field while suppressing the amount used compared to the structure of FIG.

  Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments, and various designs can be made without departing from the spirit of the present invention described in the claims. It can be changed. For example, the above-described embodiment has been described in detail for easy understanding of the present invention, and is not necessarily limited to one having all the configurations described. A part of the configuration of a certain example can be replaced with the configuration of another example, and the configuration of another example can be added to the configuration of a certain embodiment. Furthermore, it is possible to add, delete, and replace other configurations for a part of the configuration of each embodiment.

10 ... cell 11 ... battery group 100 ... shunt resistor 110 ... battery connection part 120 ... housing connection part 130 ... mechanical fixing part 140 ... solder 150 ... detection Terminal 200 ... Battery control board 300 ... Housing 310 ... Base 320 ... Cover 800 ... Secondary battery system 850 ... Battery control device

Claims (11)

A battery control device used by being connected to a battery group including one or a plurality of single cells,
The battery control device includes:
A battery control board on which a detection unit for detecting voltage is arranged;
A current of the battery group flows and a shunt resistor connected to the battery control board;
The battery control device, wherein the shunt resistor includes a machine fixing portion connected to the battery control board and a detection terminal connected to the battery control board. The battery control device according to claim 1,
The battery control device according to claim 1, wherein a diameter of the mechanical fixing portion is larger than a diameter of the detection terminal. The battery control device according to claim 2,
The shunt resistor has a battery connection part electrically connected to the battery,
The battery control device, wherein the machine fixing part is disposed between the detection terminal and the battery connection part. The battery control device according to claim 3, wherein
The battery control device includes a housing,
The shunt resistor has a housing connection part fixed to the housing,
The battery control device, wherein the housing connection part is disposed between the machine fixing part and the battery connection part. The battery control device according to claim 3, wherein
The machine fixing portion has a head portion that is in close contact with the battery control board, and a fixing portion that is in close contact with the shunt resistor,
The battery control device, wherein the battery control board and the shunt resistor are sandwiched between the head and the fixing portion. The battery control device according to claim 3 or 4,
The battery control board has a convex portion,
The battery control device, wherein the mechanical fixing portion and the detection terminal are arranged on the convex portion. The battery control device according to any one of claims 1 to 3,
The battery control device according to claim 1, wherein the detection unit is disposed in a housing and is covered with a magnetic shielding plate made of a material having a magnetic susceptibility of 10 or more. The battery control device according to claim 7,
The housing has a partition plate,
The detection unit is disposed in a closed space formed by the housing and the partition plate,
The battery control device, wherein the magnetic shielding plate is disposed so as to cover the closed space. The battery control device according to claim 7,
The magnetic shielding plate has a protrusion,
The protrusion is disposed so as to contact the battery control board, and forms a closed space between the magnetic shielding plate and the battery control board,
The battery control device according to claim 1, wherein the detection unit is disposed in a space that goes to the detection unit.   The secondary battery system provided with the battery group provided with the 1 or several cell, and the battery control apparatus in any one of Claims 1 thru | or 9. The secondary battery system according to claim 10,
The unit cell has a top surface, a bottom surface, and side surfaces connected to the top surface and the bottom surface,
The secondary battery system, wherein the battery control board is disposed on the side surface.