Voltage detection device for battery cell

Abstract

Provided is a voltage detection device for a battery cell, comprising: a battery cell (10) comprising a plurality of battery cells (12); a voltage detection means (40) that is electrically connected to the battery cell (10) and detects the voltage value of the battery cell (10); a first capacitor (61) electrically connected to the positive electrode-side end of the battery cell (10) and the negative electrode-side end of the battery cell (10); a second capacitor (62) that is electrically connected to the positive-electrode-side end of the battery cell (10) and the negative-electrode-side end of the battery cell (10), and that is provided closer to the voltage detection means (40) than the first capacitor (61); a divider resistor (70) that is provided between the battery cell (10) and the first capacitor (61) and that divides the voltage of the battery cell (10); a battery-side switch (80) provided between the battery cell (10) and the first capacitor (61); and a detection-side switch (90) provided between the first capacitor (61) and the second capacitor (62).

Description

TECHNICAL FIELD

[0001] The present application relates to a battery cell voltage detection device. BACKGROUND

[0002] For example, in Japanese Patent Application Publication No. 2002-291167, a flying capacitor type battery voltage detection device is disclosed. The battery voltage detection device has a battery cell having a plurality of battery cells, and a differential voltage detection circuit connected to the battery cell. Between the battery cell and the differential voltage detection circuit, a flying capacitor and an output side sampling switch are provided.

[0003] In the battery voltage detection device, the voltage of the battery cell is read into the flying capacitor and is output to the differential voltage detection circuit via the output side sampling switch.

[0004] PRIOR ART DOCUMENTS

[0005] PATENT DOCUMENTS

[0006] Patent Document 1: Japanese Patent Application Publication No. 2002-291167 SUMMARY

[0007] However, in the flying capacitor type battery voltage detection device disclosed in Japanese Patent Application Publication No. 2002-291167, as the voltage value of the battery cell becomes higher, the flying capacitor and the like parts can become high voltage resistance parts. By becoming high voltage resistance parts, the parts can be upsized or the number of parts can increase.

[0008] The battery cell voltage detection device disclosed herein has a battery cell including a plurality of battery cells, a voltage detection part, a first capacitor, a second capacitor, a voltage dividing resistor, a battery side switch, and a detection side switch. The voltage detection part is electrically connected to the battery cell and detects the voltage value of the battery cell. The first capacitor is electrically connected to the positive side end of the battery cell and the negative side end of the battery cell. The second capacitor is electrically connected to the positive side end of the battery cell and the negative side end of the battery cell and is provided on the voltage detection part side than the first capacitor. The voltage dividing resistor is provided between the battery cell and the first capacitor and divides the voltage of the battery cell. The battery side switch is provided between the battery cell and the first capacitor. The detection side switch is provided between the first capacitor and the second capacitor.

[0009] According to the voltage detection device for the battery cell disclosed herein, the voltage of the battery cell is accumulated in the first capacitor or the second capacitor after being divided by a voltage divider resistor. Therefore, high-voltage capacitors can be omitted from the first capacitor and the second capacitor, thus suppressing the increase in the size of components and the increase in the number of components caused by high voltage. Attached Figure Description

[0010] Figure 1 This is a schematic diagram illustrating the battery system according to the first embodiment.

[0011] Figure 2 This is a schematic diagram showing the voltage detection device according to the first embodiment.

[0012] Figure 3 This is a flowchart illustrating the process of detecting the voltage value of a battery cell in the voltage detection device according to the first embodiment.

[0013] Figure 4 This is a schematic diagram illustrating the voltage detection device according to the second embodiment.

[0014] Figure 5 This is a schematic diagram illustrating the voltage detection device according to the third embodiment.

[0015] Figure 6 This is a flowchart illustrating the process of detecting the voltage value of a battery cell in the voltage detection device according to the third embodiment.

[0016] Figure 7 This is a schematic diagram illustrating the voltage detection device according to the fourth embodiment. Detailed Implementation

[0017] The following describes one embodiment of the technology disclosed herein with reference to the accompanying drawings. Furthermore, the embodiments described herein are not intended to specifically limit the invention. The figures are schematic diagrams and do not necessarily faithfully represent actual embodiments. Additionally, components / parts that perform the same function are suitably given the same reference numerals, and repetitive descriptions are suitably omitted.

[0018] <First Implementation>

[0019] Figure 1 This is a schematic diagram illustrating the battery system 1 according to this embodiment. (As shown...) Figure 1As shown, battery system 1 is connected to load 5. Battery system 1 is a system for supplying power to load 5. Load 5 is not particularly limited. Load 5 may be, for example, a drive device such as an electric motor of a vehicle, or an inverter. A smoothing capacitor for reducing abrupt changes in current may also be connected to load 5. Here, battery system 1 is, for example, installed in a vehicle such as a hybrid electric vehicle, a plug-in hybrid electric vehicle, or an electric vehicle. In this case, battery system 1 is used as a power source to supply power to the electric motor that drives the vehicle. However, battery system 1 is not limited to use in vehicles.

[0020] like Figure 1 As shown, the battery system 1 includes a pair of output terminals 8, a battery cell 10, a first contactor 21, a second contactor 22, and a voltage detection device 30 for the battery cell 10 (hereinafter also referred to as the voltage detection device 30). The pair of output terminals 8 are connected to the load 5. The pair of output terminals 8 have an output terminal 8a on the positive side and an output terminal 8b on the negative side.

[0021] Battery unit 10 is connected to a pair of output terminals 8, and indirectly connected to load 5 via the pair of output terminals 8. Battery unit 10 supplies power to load 5. Load 5 can convert the power supplied from battery unit 10 into power or supply regenerated power to battery unit 10.

[0022] like Figure 1 As shown, the battery cell 10 includes a plurality of battery cells 12. Each battery cell 12 can be charged and discharged. For example, a secondary battery can be used as the battery cell 12. A secondary battery is a battery that can be repeatedly charged and discharged, for example, by the movement of a charge carrier between a pair of electrodes (e.g., positive and negative electrodes) via an electrolyte. For example, a lithium-ion secondary battery or a nickel-metal hydride battery can be used as the battery cell 12. In this embodiment, the battery cell 12 is a lithium-ion secondary battery. The plurality of battery cells 12 are connected in series. Here, the plurality of battery cells 12 are connected in series via a busbar (not shown). However, the plurality of battery cells 12 can also be connected in parallel. The number of battery cells 12 included in the battery cell 10 is not particularly limited and is a predetermined number. The number of battery cells 12 included in the battery cell 10 can be appropriately set according to the amount of power supplied to the load 5.

[0023] like Figure 1 As shown, the first contactor 21 is connected in series to the battery cell 10 (in other words, multiple battery cells 12 connected in series). Here, the first contactor 21 is electrically connected to the positive terminal of the battery cell 10. The first contactor 21 is located between the battery cell 10 and the positive terminal 8a. The first contactor 21 switches the electrical connection between the positive terminal of the battery cell 10 and the load 5. In other words, the contactor here is a relay or a switch.

[0024] Similar to the first contactor 21, the second contactor 22 is connected in series to the battery cell 10 (in other words, a plurality of battery cells 12 connected in series). Here, the second contactor 22 is electrically connected to the negative terminal end of the battery cell 10. The second contactor 22 is located between the battery cell 10 and the output terminal 8b on the negative terminal side. The second contactor 22 switches the electrical connection between the negative terminal end of the battery cell 10 and the load 5. Furthermore, in this embodiment, turning the contactor on means being in a connected state (closed state). Turning the contactor off means being in a disconnected state (open state). In this embodiment, the first contactor 21 and the second contactor 22 electrically switch the on and off states.

[0025] Next, the voltage detection device 30 according to this embodiment will be described. The voltage detection device 30 is a device for detecting the voltage value of the battery cell 10 (in other words, the plurality of battery cells 12 included in the battery cell 10). In this embodiment, the battery cell 10 may be high voltage. For example, the voltage value of the battery cell 10 may be in the range of 650V to 700V. Therefore, the voltage detection device 30 performs voltage division when detecting the voltage value of the battery cell 10. The voltage detection device 30 is implemented by a so-called control board.

[0026] Figure 2 This is a schematic diagram showing the voltage detection device 30. (As shown) Figure 2 As shown, the voltage detection device 30 includes the battery cell 10 and the voltage detection component 40 described above. The voltage detection component 40 detects the voltage value of the battery cell 10. The structure of the voltage detection component 40 is not particularly limited. Here, the voltage detection component 40 includes an analog-to-digital converter 41 and a controller 44. The analog-to-digital converter 41 converts an analog signal into a digital signal. In this embodiment, the analog-to-digital converter 41 obtains the voltage value of the battery cell 10 (more specifically, the voltage value after voltage division) as an analog signal. Then, after converting the analog signal into a digital signal, the analog-to-digital converter 41 outputs it to the controller 44.

[0027] The controller 44 controls the charging and discharging of the battery cell 10. Additionally, the controller 44 detects the voltage value of the battery cell 10. The structure of the controller 44 is not particularly limited. The controller 44 may be, for example, a microcomputer. The controller 44 may include, for example, an I / F (Integrated Circuit), a CPU, ROM, and RAM. The controller 44 may be composed of a single computer or multiple computers.

[0028] In this embodiment, such as Figure 1 as well as Figure 2As shown, the controller 44 is communicatively connected to the first contactor 21, the second contactor 22, and the AD converter 41. The controller 44 controls the switching of the first contactor 21 and the second contactor 22 on and off. In addition, the controller 44 can detect the voltage value of the battery cell 10 by obtaining the voltage value as a digital signal from the AD converter 41.

[0029] In this embodiment, such as Figure 2 As shown, the voltage detection device 30 includes a positive connection line 51 and a negative connection line 52. Both the positive and negative connection lines 51 and 52 are current-carrying wires. One end of the positive connection line 51 is connected to the positive terminal of the battery cell 10. The other end of the positive connection line 51 is connected to the AD converter 41 of the voltage detection component 40. One end of the negative connection line 52 is connected to the negative terminal of the battery cell 10. The other end of the negative connection line 52 is grounded.

[0030] The voltage detection device 30 includes a first capacitor 61 and a second capacitor 62. The first capacitor 61 is electrically connected to the positive terminal end and the negative terminal end of the battery cell 10. The first capacitor 61 is connected in parallel with the battery cell 10. In this embodiment, the first capacitor 61 is connected to the positive terminal connection point P11 of the intermediate portion of the positive terminal connection line 51 and the negative terminal connection point P21 of the intermediate portion of the negative terminal connection line 52. The second capacitor 62 is disposed on the side closer to the voltage detection member 40 than the first capacitor 61. The second capacitor 62 is electrically connected to the positive terminal end and the negative terminal end of the battery cell 10. The second capacitor 62 is connected in parallel with the battery cell 10 and the first capacitor 61. In this embodiment, the second capacitor 62 is connected to the positive terminal connection point P12 of the intermediate portion of the positive terminal connection line 51 and the negative terminal connection point P22 of the intermediate portion of the negative terminal connection line 52. The positive connection point P12 is positioned closer to the voltage detection component 40 than the positive connection point P11 connected to the first capacitor 61. The negative connection point P22 is positioned closer to the voltage detection component 40 than the negative connection point P21 connected to the first capacitor 61. Furthermore, the negative connection point P22 is grounded.

[0031] like Figure 2 As shown, the voltage detection device 30 includes a voltage divider resistor 70. The voltage divider resistor 70 divides the voltage from the battery cell 10. The voltage divider resistor 70 is disposed between the battery cell 10 and the first capacitor 61. In this embodiment, the voltage divider resistor 70 has a first resistor 71 and a second resistor 72.

[0032] The first resistor 71 is electrically connected to the positive terminal end of the battery cell 10. The first resistor 71 is positioned closer to the battery cell 10 than the first capacitor 61. The first resistor 71 is connected in series with the positive terminal end of the battery cell 10. Here, the first resistor 71 is positioned at the midpoint of the positive connection line 51 closer to the battery cell 10 than the positive connection point P11. The second resistor 72 is electrically connected to both the positive terminal end and the negative terminal end of the battery cell 10. The second resistor 72 is connected in parallel to the battery cell 10. The second resistor 72 is positioned closer to the battery cell 10 than the first capacitor 61. Here, the second resistor 72 is connected to the positive connection point P13 at the midpoint of the positive connection line 51 and the negative connection point P23 at the midpoint of the negative connection line 52. The positive connection point P13 is positioned between the first resistor 71 and the positive connection point P11 connecting the first capacitor 61. The negative terminal connection point P23 is located on the side of the battery cell 10 that is closer to the negative terminal connection point P21 of the first capacitor 61.

[0033] like Figure 2 As shown, the voltage detection device 30 includes a battery-side switch 80 and a detection-side switch 90. The battery-side switch 80 is disposed between the battery cell 10 and the first capacitor 61. Here, the battery-side switch 80 is disposed between the voltage divider resistor 70 and the first capacitor 61. The battery-side switch 80 is connected in series with the battery cell 10. In this embodiment, the battery-side switch 80 has a first battery-side switch 81 and a second battery-side switch 82.

[0034] The first battery-side switch 81 is electrically connected to the positive terminal end of the battery cell 10. The first battery-side switch 81 is located closer to the battery cell 10 than the first capacitor 61 and closer to the voltage detection member 40 than the first resistor 71. The first battery-side switch 81 is connected in series with the positive terminal end of the battery cell 10. Here, the first battery-side switch 81 is located at the midpoint of the positive connection line 51 closer to the battery cell 10 than the positive connection point P11. The first battery-side switch 81 is located at the midpoint of the positive connection line 51 closer to the voltage detection member 40 than the positive connection point P13. The second battery-side switch 82 is electrically connected to the negative terminal end of the battery cell 10. The second battery-side switch 82 is located closer to the battery cell 10 than the first capacitor 61. The second battery-side switch 82 is connected in series with the negative terminal end of the battery cell 10. Here, the second battery-side switch 82 is located midway along the negative connection line 52 on the side of the battery cell 10, closer to the negative connection point P21. Additionally, the second battery-side switch 82 is located midway along the negative connection line 52 on the side of the voltage detection component 40, closer to the negative connection point P23.

[0035] A detection-side switch 90 is disposed between the first capacitor 61 and the second capacitor 62. The detection-side switch 90 is connected in series with the battery cell 10. In this embodiment, the detection-side switch 90 has a first detection-side switch 91 and a second detection-side switch 92.

[0036] The first detection side switch 91 is electrically connected to the positive terminal end of the battery cell 10. The first detection side switch 91 is located closer to the voltage detection component 40 than the first capacitor 61 and closer to the battery cell 10 than the second capacitor 62. The first detection side switch 91 is connected in series with the positive terminal end of the battery cell 10. Here, the first detection side switch 91 is located in the middle portion of the positive connection line 51 closer to the voltage detection component 40 than the positive connection point P11. The first detection side switch 91 is located in the middle portion of the positive connection line 51 closer to the battery cell 10 than the positive connection point P12. The second detection side switch 92 is electrically connected to the negative terminal end of the battery cell 10. The second detection side switch 92 is located closer to the voltage detection component 40 than the first capacitor 61 and closer to the battery cell 10 than the second capacitor 62. The second detection side switch 92 is connected in series with the negative terminal end of the battery cell 10. Here, the second detection-side switch 92 is located midway along the negative terminal connection line 52 on the side closer to the voltage detection component 40 than the negative terminal connection point P21. Additionally, the second detection-side switch 92 is located midway along the negative terminal connection line 52 on the side closer to the battery cell 10 than the negative terminal connection point P22.

[0037] In this embodiment, the controller 44 of the voltage detection unit 40 is communicatively connected to the battery-side switch 80 and the detection-side switch 90. Specifically, the controller 44 is communicatively connected to the first battery-side switch 81, the second battery-side switch 82, the first detection-side switch 91, and the second detection-side switch 92. Regarding the first battery-side switch 81, the second battery-side switch 82, the first detection-side switch 91, and the second detection-side switch 92, the controller 44 controls the switching between on and off states. In this embodiment, turning a switch on means an electrically connected state (closed state). Turning a switch off means an electrically disconnected state (open state).

[0038] In this embodiment, such as Figure 2 As shown, the controller 44 includes a first control unit 45, a second control unit 46, a third control unit 47, and a fourth control unit 48. The first control unit 45 to the fourth control unit 48 can be implemented using one or more processors or using circuits.

[0039] Next, along Figure 3 The flowchart illustrates the control process of the controller 44 of the voltage detection component 40. In this embodiment, when the voltage value of the battery cell 10 is detected using the voltage detection device 30, the following steps are first executed:Figure 3 Step S101. In step S101, Figure 2 The first control unit 45 turns the battery-side switch 80 on and turns the detection-side switch 90 off. Specifically, the first control unit 45 turns on the first battery-side switch 81 and the second battery-side switch 82, and turns off the first detection-side switch 91 and the second detection-side switch 92. Thus, the battery-side switch 80 (here, the first battery-side switch 81 and the second battery-side switch 82) is in a closed state, and the detection-side switch 90 (here, the first detection-side switch 91 and the second detection-side switch 92) is in an open state.

[0040] When the control unit 45 is executed, the voltage of the battery cell 10 is divided using the voltage divider resistor 70. The divided voltage (e.g., a predetermined amount of voltage) is stored in the first capacitor 61. Furthermore, the method by which the controller 44 determines whether voltage has been stored in the first capacitor 61 is not particularly limited. For example, after the control unit 45 is executed, a predetermined first elapsed time may be elapsed to determine whether voltage has been stored in the first capacitor 61. The first elapsed time is between 2 msec and 20 msec, for example, it can be 2 msec or 20 msec. For example, 20 msec.

[0041] In this embodiment, after the control of the first control unit 45, the voltage is accumulated in the first capacitor 61, and then, execution is performed. Figure 3 Step S102. In step S102, Figure 2 The second control unit 46 switches the first battery-side switch 81 and the second battery-side switch 82 from on to off. Here, the first battery-side switch 81, which was in the closed state, is changed to the open state. Similarly, the second battery-side switch 82, which was in the closed state, is changed to the open state. Furthermore, in step S102, the first detection-side switch 91 and the second detection-side switch 92 remain off (i.e., in the open state) as before.

[0042] Next, in Figure 3 In step S103, Figure 2 After being controlled by the second control unit 46, the third control unit 47 switches the first detection side switch 91 and the second detection side switch 92 from off to on. Here, the first detection side switch 91, which was in the off state, is changed to the closed state. Similarly, the second detection side switch 92, which was in the off state, is changed to the closed state.

[0043] When the control of the third control unit 47 is executed, the voltage stored in the first capacitor 61 (e.g., a predetermined amount of voltage) is stored in the second capacitor 62. Furthermore, the method by which the controller 44 determines whether voltage has been stored in the second capacitor 62 is not particularly limited. For example, similar to the case of the first capacitor 61, after the control of the third control unit 47 is executed, a predetermined second elapsed time may be elapsed to determine that voltage has been stored in the second capacitor 62. The second elapsed time is the same as the first elapsed time. However, the second elapsed time may also be different from the first elapsed time. The second elapsed time is between 2 msec and 20 msec, for example, it may be around 2 msec or 20 msec.

[0044] In this embodiment, after the voltage is stored in the second capacitor 62, the AD converter 41 obtains an analog signal based on the voltage stored in the second capacitor 62 and performs AD conversion. The controller 44 receives the digital signal converted by the AD converter 41 and calculates the voltage value before voltage division, which is the voltage value of the battery cell 10, based on the digital signal.

[0045] In this embodiment, after the control of the third control unit 47, the voltage is accumulated in the second capacitor 62, and then, execution is performed. Figure 3 Step S104. In step S104, Figure 2 The fourth control unit 48 switches the first detection side switch 91 and the second detection side switch 92 from on to off. Here, the first detection side switch 91, which was in the closed state, is changed to the open state. Similarly, the second detection side switch 92, which was in the closed state, is changed to the open state. Furthermore, in step S104, the first battery side switch 81 and the second battery side switch 82 remain off (i.e., in the open state). In this way, the voltage detection device 30 can detect the voltage value of the battery cell 10.

[0046] In this embodiment, as described above... Figure 2As shown, the voltage detection device 30 of the battery cell 10 includes a battery cell 10 comprising multiple battery cells 12, a voltage detection component 40, a first capacitor 61, a second capacitor 62, a voltage divider resistor 70, a battery-side switch 80, and a detection-side switch 90. The voltage detection component 40 is electrically connected to the battery cell 10 and detects the voltage value of the battery cell 10. The first capacitor 61 is electrically connected to both the positive and negative terminals of the battery cell 10. The second capacitor 62 is electrically connected to both the positive and negative terminals of the battery cell 10 and is located closer to the voltage detection component 40 than the first capacitor 61. The voltage divider resistor 70 is located between the battery cell 10 and the first capacitor 61 to divide the voltage of the battery cell 10. The battery-side switch 80 is located between the battery cell 10 and the first capacitor 61. The detection-side switch 90 is located between the first capacitor 61 and the second capacitor 62. In this embodiment, when detecting the voltage value of the battery cell 10, the voltage of the battery cell 10 is divided by the voltage divider resistor 70 and then stored in the first capacitor 61 or the second capacitor 62. Therefore, high-voltage capacitors can be avoided for the first capacitor 61 and the second capacitor 62, thus suppressing the increase in the size of parts and the increase in the number of parts caused by high voltage.

[0047] In this embodiment, such as Figure 2 As shown, the battery-side switch 80 is positioned between the voltage divider resistor 70 and the first capacitor 61. Therefore, by switching the battery-side switch 80 on and off, it is possible to control whether the voltage divided by the voltage divider resistor 70 is applied to the first capacitor 61.

[0048] In this embodiment, the voltage divider resistor 70 has a first resistor 71 electrically connected to the positive terminal end of the battery cell 10 and a second resistor 72 electrically connected to both the positive terminal end and the negative terminal end of the battery cell 10. Thus, the voltage applied from the battery cell 10 can be divided using the first resistor 71 and the second resistor 72.

[0049] In this embodiment, such as Figure 2 As shown, the battery-side switch 80 has a first battery-side switch 81 electrically connected to the positive terminal of the battery cell 10 and a second battery-side switch 82 electrically connected to the negative terminal of the battery cell 10. The detection-side switch 90 has a first detection-side switch 91 electrically connected to the positive terminal of the battery cell 10 and a second detection-side switch 92 electrically connected to the negative terminal of the battery cell 10. The voltage detection unit 40 includes an AD converter 41 electrically connected to the battery cell 10 and a controller 44 electrically connected to the AD converter 41. The controller 44 includes a first control unit 45, a second control unit 46, a third control unit 47, and a fourth control unit 48. The first control unit 45...Figure 3 In step S101, the first battery-side switch 81 and the second battery-side switch 82 are turned on, and the first detection-side switch 91 and the second detection-side switch 92 are turned off. This prevents the application of voltage to the second capacitor 62 while voltage is being accumulated in the first capacitor 61.

[0050] After the second control unit 46 receives control from the first control unit 45, the voltage is accumulated in the first capacitor 61. Figure 3 In step S102, the first battery-side switch 81 and the second battery-side switch 82 are switched off. The third control unit 47, after being controlled by the second control unit 46, then... Figure 3 In step S103, the first detection side switch 91 and the second detection side switch 92 are switched on. After the third control unit 47 controls the fourth control unit 48, the voltage is accumulated in the second capacitor 62, and then... Figure 3 In step S104, the first detection side switch 91 and the second detection side switch 92 are switched off. To accumulate the voltage stored in the first capacitor 61 into the second capacitor 62, the detection side switch 90 is switched on after the battery side switch 80 is switched off, thereby preventing leakage to the battery cell 10.

[0051] <Second Implementation Method>

[0052] Next, the voltage detection device 30A according to the second embodiment will be described. Figure 4 This is a schematic diagram showing the voltage detection device 30A according to the second embodiment. Voltage detection device 30A according to the second embodiment (see reference) Figure 4 ) and the voltage detection device 30 according to the first embodiment (see reference) Figure 2 Compared to the voltage divider resistor 70, the structure of the voltage divider resistor is different.

[0053] In this embodiment, such as Figure 4 As shown, the voltage detection device 30A includes a voltage divider resistor 70A. The voltage divider resistor 70A has a first resistor 71, a second resistor 72, and a third resistor 73. Here, the first resistor 71 and the second resistor 72 are respectively connected to... Figure 2 The first resistor 71 and the second resistor 72 of the voltage detection device 30 according to the first embodiment shown are the same. By adding a third resistor 73 to the voltage detection device 30 according to the first embodiment, it becomes the voltage detection device 30A according to the second embodiment.

[0054] like Figure 4As shown, the third resistor 73 is electrically connected to the negative terminal end of the battery cell 10. The third resistor 73 is located closer to the battery cell 10 than the first capacitor 61 and the second battery-side switch 82. The third resistor 73 is connected in series with the negative terminal end of the battery cell 10. Here, the third resistor 73 is located in the middle portion of the negative terminal connection line 52 closer to the battery cell 10 than the negative terminal connection point P21 of the first capacitor 61. Additionally, the third resistor 73 is located in the middle portion of the negative terminal connection line 52 closer to the battery cell 10 than the negative terminal connection point P23 of the second resistor 72.

[0055] In this embodiment, the control process of the controller 44 of the voltage detection component 40 is the same as that in the first embodiment. That is, in this embodiment, by following... Figure 3 The flowchart shows the control of the controller 44, which can detect the voltage value of the battery cell 10.

[0056] In this embodiment, the same effects as in the first embodiment are achieved. Furthermore, in this embodiment, as... Figure 4 As shown, the voltage divider resistor 70A includes a third resistor 73 in addition to the first resistor 71 and the second resistor 72. The third resistor 73 is electrically connected to the negative terminal of the battery cell 10. Therefore, even if any of the battery-side switches 80 fails and remains closed, the voltage divider resistor 70A ensures a large resistance value. Thus, leakage current to the battery cell 10 due to high voltage can be suppressed.

[0057] <Third Implementation Method>

[0058] Next, the voltage detection device 30B according to the third embodiment will be described. Figure 5 This is a schematic diagram showing the voltage detection device 30B according to the third embodiment. The voltage detection device 30B according to the third embodiment (see reference) Figure 5 ) and the voltage detection device 30A according to the second embodiment (see reference) Figure 4 In comparison, the structure and location of the battery-side switch 80 and the structure of the controller 44 are different.

[0059] In this embodiment, such as Figure 5 As shown, the voltage detection device 30B includes the same voltage divider resistor 70A, battery-side switch 80B, and voltage detection component 40B as in the second embodiment. The voltage detection device 30A according to the second embodiment (see reference...) Figure 4 In the third embodiment, the battery-side switch 80 is changed to a battery-side switch 80B and the voltage detection component 40 is changed to a voltage detection component 40B, thus becoming the voltage detection device 30B involved in the third embodiment.

[0060] In this embodiment, such as Figure 5 As shown, the battery-side switch 80B includes a first battery-side switch 81B, a second battery-side switch 82B, and a third battery-side switch 83B. The first battery-side switch 81B is electrically connected to the positive terminal end of the battery cell 10. The first battery-side switch 81B is located on the side of the first resistor 71 (which is closer to the voltage divider resistor 70A) near the battery cell 10. Here, the first battery-side switch 81B is connected in series with the positive terminal end of the battery cell 10. The first battery-side switch 81B is located in the middle portion of the positive terminal connection line 51 (closer to the battery cell 10 side than the first resistor 71).

[0061] The second battery-side switch 82B is electrically connected to the negative terminal end of the battery cell 10. The second battery-side switch 82B is located on the side of the third resistor 73 (which is closer to the voltage divider resistor 70A) near the battery cell 10. Here, the second battery-side switch 82B is connected in series with the negative terminal end of the battery cell 10. The second battery-side switch 82B is located in the middle portion of the negative terminal connection line 52, closer to the battery cell 10 than the third resistor 73.

[0062] The third battery-side switch 83B is electrically connected to the positive terminal end of the battery cell 10. The third battery-side switch 83B is located closer to the battery cell 10 than the first capacitor 61 and closer to the voltage detection component 40B than the first resistor 71 (which is connected to the voltage divider resistor 70A). The third battery-side switch 83B is connected in series with the positive terminal end of the battery cell 10. Here, the third battery-side switch 83B is located in the middle portion of the positive connection line 51 closer to the battery cell 10 than the positive connection point P11 of the first capacitor 61. The third battery-side switch 83B is located in the middle portion of the positive connection line 51 closer to the voltage detection component 40B than the positive connection point P13 of the second resistor 72 (which is connected to the voltage divider resistor 70A).

[0063] Furthermore, the third battery-side switch 83B may also be connected in series with the negative terminal side of the battery cell 10 instead of the positive terminal side of the battery cell 10. In this case, the third battery-side switch 83B may also be located in the middle of the negative terminal connection line 52, which is closer to the battery cell 10 side than the negative terminal connection point P21 of the first capacitor 61 and closer to the voltage detection component 40B side than the negative terminal connection point P23 of the second resistor 72.

[0064] In this embodiment, such as Figure 5 As shown, the voltage detection unit 40B includes the same AD converter 41 and controller 44B as in the first embodiment. Here, the controller 44B includes a first control unit 45B, a second control unit 46B, a third control unit 47B, a fourth control unit 48B, and a fifth control unit 49B. The first control unit 45B to the fifth control unit 49B can be implemented using one or more processors, or they can be implemented using circuitry.

[0065] Next, along Figure 6 The flowchart illustrates the control process of the controller 44B of the voltage detection component 40B involved in this embodiment. In this embodiment, when detecting the voltage value of the battery cell 10 using the voltage detection device 30B, the following steps are first executed: Figure 6 Step S201. In step S201, Figure 5 The first control unit 45B turns the battery-side switch 80B on and turns the detection-side switch 90 off. The first control unit 45B turns on the first battery-side switch 81B, the second battery-side switch 82B, and the third battery-side switch 83B, and turns off the first detection-side switch 91 and the second detection-side switch 92. Thus, the battery-side switch 80B (and here the first battery-side switch 81B, the second battery-side switch 82B, and the third battery-side switch 83B) is in a closed state. The detection-side switch 90 (and here the first detection-side switch 91 and the second detection-side switch 92) is in an open state.

[0066] When the control unit 45B is executed, the voltage of the battery cell 10 is divided using the voltage divider resistor 70A. The divided voltage (e.g., a predetermined amount of voltage) is stored in the first capacitor 61. For example, after the controller 44B executes the control unit 45B, a predetermined first elapsed time is elapsed, thereby determining that voltage has been stored in the first capacitor 61.

[0067] In this embodiment, after the control of the first control unit 45B, the voltage is accumulated in the first capacitor 61, and then, execution is performed. Figure 6 Step S202. In step S202, Figure 5 The second control unit 46B switches the third battery-side switch 83B from ON to OFF. Here, the closed third battery-side switch 83B is changed to the OFF state. Next, in Figure 6 In step S203, Figure 5 After being controlled by the second control unit 46B, the third control unit 47B switches the first battery-side switch 81B and the second battery-side switch 82B from ON to OFF. Here, the closed first battery-side switch 81B is changed to OFF. Similarly, the closed second battery-side switch 82B is changed to OFF. In this embodiment, when all the closed battery-side switches 80B are changed to OFF, the first battery-side switch 81B and the second battery-side switch 82B are first made OFF after the third battery-side switch 83B is made OFF. Furthermore, in step S203, the first detection-side switch 91 and the second detection-side switch 92 remain OFF (i.e., OFF).

[0068] Next, in Figure 6 In step S204, Figure 5 After being controlled by the third control unit 47B, the fourth control unit 48B switches the first detection side switch 91 and the second detection side switch 92 from off to on. Here, the first detection side switch 91, which was in the off state, is changed to the closed state. Similarly, the second detection side switch 92, which was in the off state, is changed to the closed state.

[0069] When the control of the fourth control unit 48B is executed, the voltage stored in the first capacitor 61 (e.g., a predetermined amount of voltage) is stored in the second capacitor 62. For example, after the controller 44B executes the control of the fourth control unit 48B, a predetermined second elapsed time is elapsed, thereby determining that voltage has been stored in the second capacitor 62. In this embodiment, after the voltage is stored in the second capacitor 62, the AD converter 41 obtains an analog signal based on the voltage stored in the second capacitor 62 and performs AD conversion. The controller 44B receives the digital signal converted by the AD converter 41 and calculates the voltage value before voltage division, which is the voltage value of the battery cell 10, based on the digital signal.

[0070] In this embodiment, after the control of the fourth control unit 48B, the voltage is accumulated in the second capacitor 62, and then, execution is performed. Figure 6 Step S205. In step S205, Figure 5 The fifth control unit 49B switches the first detection side switch 91 and the second detection side switch 92 from on to off. Here, the first detection side switch 91, which was in the closed state, is changed to the open state. Similarly, the second detection side switch 92, which was in the closed state, is changed to the open state. Furthermore, in step S205, the first battery side switch 81B, the second battery side switch 82B, and the third battery side switch 83B remain off (i.e., in the open state). In this way, the voltage detection device 30B can detect the voltage value of the battery cell 10.

[0071] In this embodiment, the same effects as in the first and second embodiments are achieved. Furthermore, in this embodiment, as... Figure 5As shown, the battery-side switch 80B includes a first battery-side switch 81B, a second battery-side switch 82B, and a third battery-side switch 83B. The first battery-side switch 81B is located on the side of the voltage divider resistor 70A closest to the battery cell 10 and is electrically connected to the positive terminal of the battery cell 10. The second battery-side switch 82B is located on the side of the voltage divider resistor 70A closest to the battery cell 10 and is electrically connected to the negative terminal of the battery cell 10. The third battery-side switch 83B is located between the voltage divider resistor 70A and the first capacitor 61. Thus, the first battery-side switch 81B and the second battery-side switch 82B are located on the side of the voltage divider resistor 70A closest to the battery cell 10. The third battery-side switch 83B is located on the side of the voltage divider resistor 70A closest to the voltage detection component 40B. Therefore, by turning on the first battery-side switch 81B and the second battery-side switch 82B only when the voltage is accumulated in the first capacitor 61, the average heat generation of the voltage divider resistor 70A can be reduced. As a result, the temperature rise of the voltage detection device 30B can be suppressed.

[0072] In this embodiment, after the voltage is accumulated in the first capacitor 61 following the control of the first control unit 45B, the second control unit 46B of the controller 44B... Figure 6 In step S202, the third battery-side switch 83B is switched to off. Following the control of the second control unit 46B, the third control unit 47B of the controller 44B... Figure 6 In step S203, the first battery-side switch 81B and the second battery-side switch 82B are switched off. In this way, after the voltage is accumulated in the first capacitor 61 and the third battery-side switch 83B is turned off, the first battery-side switch 81B and the second battery-side switch 82B are turned off, thereby preventing leakage to the battery cell 10.

[0073] <Fourth Implementation>

[0074] Next, the voltage detection device 30C according to the fourth embodiment will be described. Figure 7 This is a schematic diagram showing the voltage detection device 30C according to the fourth embodiment. The voltage detection device 30C according to the fourth embodiment (see reference) Figure 7 Regarding the voltage detection device 30B according to the third embodiment (see reference 30B) Figure 5 Added Zener diode 95.

[0075] In this embodiment, such as Figure 7 As shown, the voltage detection device 30C and the voltage detection device 30B according to the third embodiment (see reference) Figure 5Compared to the third embodiment, it also includes a Zener diode 95. That is, by adding a Zener diode 95 to the voltage detection device 30B according to the third embodiment, it becomes the voltage detection device 30C according to the fourth embodiment.

[0076] like Figure 7 As shown, the Zener diode 95 is electrically connected to both the positive and negative terminals of the battery cell 10. The Zener diode 95 is connected in parallel with the battery cell 10. The Zener diode 95 is disposed between at least one of the battery-side switch 80B (specifically, the third battery-side switch 83B) and the first capacitor 61, and between the detection-side switch 90 and the second capacitor 62. In this embodiment, the Zener diode 95 includes a first Zener diode 96 and a second Zener diode 97.

[0077] The first Zener diode 96 is electrically connected to both the positive and negative ends of the battery cell 10. The first Zener diode 96 is connected in parallel with the battery cell 10. In this embodiment, the first Zener diode 96 is disposed between the third battery-side switch 83B and the first capacitor 61 of the battery-side switch 80B. The first Zener diode 96 is connected to the positive connection point P14 at the midpoint of the positive connection line 51 and the negative connection point P24 at the midpoint of the negative connection line 52. The positive connection point P14 is positioned closer to the battery cell 10 than the positive connection point P11 connected to the first capacitor 61. The positive connection point P14 is positioned closer to the voltage detection component 40B than the positive connection point P13 connected to the second resistor 72 and the third battery-side switch 83B. Furthermore, the negative connection point P24 is positioned closer to the battery cell 10 than the negative connection point P21 connected to the first capacitor 61. The negative connection point P24 is located on the side closer to the voltage detection component 40B than the negative connection point P23 connected to the second resistor 72.

[0078] The second Zener diode 97 is electrically connected to both the positive and negative ends of the battery cell 10. The second Zener diode 97 is connected in parallel with the battery cell 10. In this embodiment, the second Zener diode 97 is disposed between the detection-side switch 90 (specifically, the first detection-side switch 91 and the second detection-side switch 92) and the second capacitor 62. Here, the second Zener diode 97 is connected to the positive connection point P15 at the midpoint of the positive connection line 51 and the negative connection point P25 at the midpoint of the negative connection line 52. The positive connection point P15 is positioned closer to the voltage detection component 40B than the positive connection points P11 and P14. The positive connection point P15 is positioned closer to the battery cell 10 than the positive connection point P12 connecting the second capacitor 62. Furthermore, the negative connection point P25 is positioned closer to the voltage detection component 40B than the negative connection points P21 and P24. The negative terminal connection point P25 is located on the side of the battery cell 10, which is closer to the negative terminal connection point P22 of the second capacitor 62.

[0079] In this embodiment, the control process of the controller 44B for the voltage detection component 40B is the same as that in the third embodiment. That is, in this embodiment, by following... Figure 6 The flowchart shows the control of controller 44B, which can detect the voltage value of battery cell 10.

[0080] In this embodiment, the same effects as in embodiments 1 to 3 are obtained. Furthermore, in this embodiment, as... Figure 7 As shown, a Zener diode 95 is provided at least one of the following: between the third battery-side switch 83B and the first capacitor 61; and between the detection-side switch 90 and the second capacitor 62. Therefore, even if a fault occurs in the battery-side switch 80B, the detection-side switch 90, or the voltage divider resistor 70A, or if the positive and negative terminals of the battery cell 10 are reverse-connected, the Zener diode 95 can be used to prevent components located closer to the voltage detection component 40B than the Zener diode 95 from malfunctioning.

[0081] As stated above, the following disclosures are included in this specification.

[0082] Item 1:

[0083] A voltage detection device for a battery cell, comprising:

[0084] A battery cell, comprising multiple individual battery cells;

[0085] A voltage detection component is electrically connected to the battery cell to detect the voltage value of the battery cell;

[0086] The first capacitor is electrically connected to the positive terminal end and the negative terminal end of the battery cell.

[0087] The second capacitor is electrically connected to the positive terminal end and the negative terminal end of the battery cell, and is disposed closer to the voltage detection component than the first capacitor.

[0088] A voltage divider resistor is disposed between the battery cell and the first capacitor to divide the voltage of the battery cell.

[0089] A battery-side switch is disposed between the battery cell and the first capacitor; and

[0090] A detection-side switch is disposed between the first capacitor and the second capacitor.

[0091] Item 2: The voltage detection device for the battery cell according to Item 1, wherein,

[0092] The battery-side switch is located between the voltage divider resistor and the first capacitor.

[0093] Item 3: The voltage detection device for the battery cell according to Item 2, wherein,

[0094] The battery-side switch has:

[0095] The first battery-side switch is electrically connected to the positive terminal end of the battery cell; and

[0096] The second battery-side switch is electrically connected to the negative terminal end of the battery cell.

[0097] The detection-side switch has:

[0098] The first detection-side switch is electrically connected to the positive terminal end of the battery cell; and

[0099] The second detection-side switch is electrically connected to the negative terminal end of the battery cell.

[0100] The voltage detection component includes:

[0101] An AD converter is electrically connected to the battery cell; and

[0102] The controller is electrically connected to the AD converter.

[0103] The controller has:

[0104] The first control unit turns on the first battery-side switch and the second battery-side switch, and turns off the first detection-side switch and the second detection-side switch.

[0105] The second control unit, after the control of the first control unit and after the voltage is accumulated in the first capacitor, switches the first battery-side switch and the second battery-side switch to off.

[0106] The third control unit, after being controlled by the second control unit, switches the first detection side switch and the second detection side switch to the ON position; and

[0107] After the control of the third control unit, and after the voltage is accumulated in the second capacitor, the fourth control unit switches the first detection side switch and the second detection side switch to the off position.

[0108] Item 4: The voltage detection device for the battery cell according to Item 1, wherein,

[0109] The voltage divider resistor has the following characteristics:

[0110] The first resistor is electrically connected to the positive terminal of the battery cell; and

[0111] The second resistor is electrically connected to the positive terminal end and the negative terminal end of the battery cell.

[0112] Item 5: The voltage detection device for the battery cell according to Item 4, wherein,

[0113] The voltage divider resistor has a third resistor that is electrically connected to the end of the negative terminal of the battery cell.

[0114] Item 6: The voltage detection device for the battery cell according to Item 5, wherein,

[0115] The battery-side switch has:

[0116] The first battery-side switch is located closer to the battery cell than the voltage divider resistor and is electrically connected to the end of the positive terminal of the battery cell.

[0117] A second battery-side switch is disposed closer to the battery cell than the voltage divider resistor and is electrically connected to the negative terminal of the battery cell; and

[0118] The third battery-side switch is located between the voltage divider resistor and the first capacitor.

[0119] Item 7: The voltage detection device for the battery cell according to Item 6, wherein,

[0120] The detection-side switch has:

[0121] The first detection-side switch is electrically connected to the positive terminal end of the battery cell; and

[0122] The second detection-side switch is electrically connected to the negative terminal end of the battery cell.

[0123] The voltage detection component includes:

[0124] An AD converter is electrically connected to the battery cell; and

[0125] The controller is electrically connected to the AD converter.

[0126] The controller has:

[0127] The first control unit turns on the first battery-side switch, the second battery-side switch, and the third battery-side switch, and turns off the first detection-side switch and the second detection-side switch.

[0128] The second control unit, after the control of the first control unit, and after the voltage is accumulated in the first capacitor, switches the third battery-side switch to off;

[0129] The third control unit, after being controlled by the second control unit, switches the first battery-side switch and the second battery-side switch to the off position;

[0130] The fourth control unit, after being controlled by the third control unit, switches the first detection side switch and the second detection side switch to the ON position; and

[0131] After the fourth control unit controls the second capacitor and the voltage is accumulated, the fifth control unit switches the first detection side switch and the second detection side switch to the off position.

[0132] Item 8: A voltage detection device for a battery cell according to Item 6 or 7, wherein,

[0133] A Zener diode is provided, which is disposed between the third battery-side switch and the first capacitor and between the detection-side switch and the second capacitor, and is electrically connected to the positive terminal end and the negative terminal end of the battery cell.

[0134] (Explanation of reference numerals in the attached diagram)

[0135] 1: Battery system; 10: Battery cell; 12: Single battery cell; 30, 30A, 30B, 30C: Voltage detection device (voltage detection device for battery cell); 40, 40B: Voltage detection component; 41: AD converter; 44, 44B: Controller; 45, 45B: First control unit; 46, 46B: Second control unit; 47, 47B: Third control unit; 48, 48B: Fourth control unit; 49B: Fifth control unit; 61: First capacitor ; 62: Second capacitor; 70, 70A: Voltage divider resistors; 71: First resistor; 72: Second resistor; 73: Third resistor; 80, 80B: Battery side switch; 81, 81B: First battery side switch; 82, 82B: Second battery side switch; 83B: Third battery side switch; 90: Detection side switch; 91: First detection side switch; 92: Second detection side switch; 95: Zener diode; 96: First Zener diode; 97: Second Zener diode.

Claims

1. A voltage detection device for a battery cell, comprising: A battery cell, comprising multiple individual battery cells; A voltage detection component is electrically connected to the battery cell to detect the voltage value of the battery cell; The first capacitor is electrically connected to the positive terminal end and the negative terminal end of the battery cell. The second capacitor is electrically connected to the positive terminal end and the negative terminal end of the battery cell, and is disposed closer to the voltage detection component than the first capacitor. A voltage divider resistor is disposed between the battery cell and the first capacitor to divide the voltage of the battery cell. A battery-side switch is disposed between the battery cell and the first capacitor; as well as A detection-side switch is disposed between the first capacitor and the second capacitor.

2. The voltage detection device for a battery cell according to claim 1, wherein, The battery-side switch is located between the voltage divider resistor and the first capacitor.

3. The voltage detection device for a battery cell according to claim 2, wherein, The battery-side switch has: The first battery-side switch is electrically connected to the positive terminal end of the battery cell; and The second battery-side switch is electrically connected to the negative terminal end of the battery cell. The detection-side switch has: The first detection-side switch is electrically connected to the positive terminal end of the battery cell; and The second detection-side switch is electrically connected to the negative terminal end of the battery cell. The voltage detection component includes: An AD converter is electrically connected to the battery cell; and The controller is electrically connected to the AD converter. The controller has: The first control unit turns on the first battery-side switch and the second battery-side switch, and turns off the first detection-side switch and the second detection-side switch. The second control unit, after the control of the first control unit and after the voltage is accumulated in the first capacitor, switches the first battery-side switch and the second battery-side switch to off. The third control unit, after being controlled by the second control unit, switches the first detection side switch and the second detection side switch to the ON position; as well as After the control of the third control unit, and after the voltage is accumulated in the second capacitor, the fourth control unit switches the first detection side switch and the second detection side switch to the off position.

4. The voltage detection device for a battery cell according to claim 1, wherein, The voltage divider resistor has the following characteristics: The first resistor is electrically connected to the positive terminal of the battery cell; and The second resistor is electrically connected to the positive terminal end and the negative terminal end of the battery cell.

5. The voltage detection device for a battery cell according to claim 4, wherein, The voltage divider resistor has a third resistor that is electrically connected to the end of the negative terminal of the battery cell.

6. The voltage detection device for a battery cell according to claim 5, wherein, The battery-side switch has: The first battery-side switch is located closer to the battery cell than the voltage divider resistor and is electrically connected to the end of the positive terminal of the battery cell. The second battery-side switch is located closer to the battery cell than the voltage divider resistor and is electrically connected to the end of the negative terminal of the battery cell. as well as The third battery-side switch is located between the voltage divider resistor and the first capacitor.

7. The voltage detection device for a battery cell according to claim 6, wherein, The detection-side switch has: The first detection-side switch is electrically connected to the positive terminal end of the battery cell; and The second detection-side switch is electrically connected to the negative terminal end of the battery cell. The voltage detection component includes: An AD converter is electrically connected to the battery cell; and The controller is electrically connected to the AD converter. The controller has: The first control unit turns on the first battery-side switch, the second battery-side switch, and the third battery-side switch, and turns off the first detection-side switch and the second detection-side switch. The second control unit, after the voltage is accumulated in the first capacitor following the control of the first control unit, switches the third battery-side switch to off. The third control unit, after being controlled by the second control unit, switches the first battery-side switch and the second battery-side switch to the off position; The fourth control unit, after being controlled by the third control unit, switches the first detection side switch and the second detection side switch to the ON position; as well as After the fourth control unit controls the second capacitor and the voltage is accumulated, the fifth control unit switches the first detection side switch and the second detection side switch to the off position.

8. The voltage detection device for a battery cell according to claim 6 or 7, wherein, The device includes a Zener diode disposed between at least one of the third battery-side switch and the first capacitor and between the detection-side switch and the second capacitor, and the Zener diode is electrically connected to the positive terminal end and the negative terminal end of the battery cell.

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