Vehicle connection circuit and vehicle battery structure

Abstract

In vehicles equipped with multiple batteries, relay malfunctions are detected using the minimum necessary current sensors. [Solution] The junction block 20 is interposed between the first battery 11 and the second battery 12, which are provided in the vehicle and configured to be connectable to each other, and the motor 40, and electrically connects the first battery 11, the second battery 12, and the motor 40. The junction block 20 includes a first path 51 that charges only the first battery 11 and is provided with a first current sensor 23, a second path 52 that charges only the second battery 12, a third path 53 that charges both the first battery 11 and the second battery 12, and a second current sensor 27 provided in the portion where the second path 52 and the third path 53 overlap but do not overlap with the first path 51, for measuring the current flowing through the second battery 12.

Description

Technical Field

[0001] The present disclosure relates to a vehicle connection circuit and a vehicle battery structure.

Background Art

[0002] Patent Document 1 describes a battery pack having a structure that can suppress an electrical short circuit between a positive electrode side device and a negative electrode side device with a simple structure when an impact load acts on the battery pack.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, in a vehicle equipped with a plurality of batteries, a vehicle connection circuit (hereinafter, also referred to as a "junction block") that can be connected to the plurality of batteries may be provided. In this junction block, a current sensor may be arranged to detect malfunction of a relay. In this case, it is desired to arrange the minimum necessary current sensor from the viewpoints of cost reduction and simplification of the structure, but depending on the location where the current sensor is arranged, malfunction of the relay may not be detected.

[0005] An object of the present disclosure is to provide a vehicle connection circuit and a vehicle battery structure that can detect malfunction of a relay by a minimum necessary current sensor in a vehicle equipped with a plurality of batteries.

Means for Solving the Problems

[0006] The vehicle connection circuit according to claim 1 is a vehicle connection circuit interposed between a first battery and a second battery, which are provided in a vehicle and configured to be connectable to each other, and a motor, and electrically connects the first battery, the second battery, and the motor, and includes a first path for charging only the first battery, a second path for charging only the second battery, a third path for charging both the first battery and the second battery, and a current sensor provided in the portion where the second path and the third path overlap but do not overlap with the first path, for measuring the current flowing through the second battery.

[0007] In the vehicle connection circuit according to claim 1, in a vehicle equipped with multiple batteries, relay malfunctions can be detected using the minimum necessary number of current sensors. Here, "minimum necessary" means that the number of current sensors is the minimum necessary, and for example, in the case of two batteries connected in parallel and in series, relay malfunctions can be detected with at least one current sensor in each case. This reduces costs and simplifies the structure.

[0008] The vehicle connection circuit according to claim 2 is the vehicle connection circuit according to claim 1, wherein the current sensor is positioned between the confluence point of the second path and the third path and the positive side of the second battery, or between the negative side of the second battery and the confluence point of the first path and the second path.

[0009] In the vehicle connection circuit according to claim 2, a malfunction of the relay can be detected by at least one current sensor in both the case where two batteries are connected in parallel and in the case where they are connected in series.

[0010] The vehicle connection circuit according to claim 3 further includes, in the vehicle connection circuit according to claim 1, another current sensor provided in the portion where the first path and the third path overlap but do not overlap with the second path, for measuring the current flowing through the first battery.

[0011] In the vehicle connection circuit according to claim 3, relay malfunctions can be detected with greater accuracy by comparing the currents measured by two current sensors.

[0012] The vehicle connection circuit according to claim 4 is the vehicle connection circuit according to claim 1, wherein a relay is provided in the first path at a position that does not overlap with the second path and the third path, and another relay is provided in the third path at a position that does not overlap with the first path and the second path, and the current sensor measures the short-circuit current caused by a malfunction of the other relay when the first battery and the second battery are connected in parallel, and measures the short-circuit current caused by a malfunction of the relay when the first battery and the second battery are connected in series.

[0013] The vehicle connection circuit according to claim 4 can measure the short-circuit current caused by a relay malfunction.

[0014] The vehicle battery structure according to claim 5 comprises a first battery, a second battery configured to be connectable to the first battery, and a vehicle connection circuit according to any one of claims 1 to 4, which is interposed between the first battery, the second battery, and a motor, and electrically connects the first battery, the second battery, and the motor.

[0015] In the vehicle battery structure according to claim 5, in a vehicle equipped with multiple batteries, a relay malfunction can be detected by the minimum necessary current sensor. [Effects of the Invention]

[0016] As described above, according to this disclosure, in a vehicle equipped with multiple batteries, a relay malfunction can be detected using the minimum necessary current sensors. [Brief explanation of the drawing]

[0017] [Figure 1]It is a block diagram showing an example of the configuration of a vehicle battery structure mounted on a vehicle according to an embodiment. [Figure 2] It is a diagram showing an example of the circuit configuration of a vehicle battery structure according to an embodiment. [Figure 3] It is a diagram showing an example of the circuit configuration of a vehicle battery structure according to an embodiment. [Figure 4] It is a diagram showing an example of the circuit configuration of a vehicle battery structure according to an embodiment. [Figure 5] It is a diagram showing the circuit configuration of a vehicle battery structure according to a modified example.

Mode for Carrying Out the Invention

[0018] Hereinafter, an example of a mode for carrying out the technology of the present disclosure will be described in detail with reference to the drawings.

[0019] FIG. 1 is a block diagram showing an example of the configuration of a vehicle battery structure 100 mounted on a vehicle 200 according to the present embodiment. As shown in FIG. 1, the vehicle 200 according to the present embodiment is equipped with a vehicle battery structure 100 and a motor 40 for driving the vehicle 200. The vehicle battery structure 100 includes a battery 10 and a junction block 20, and the battery 10 includes a first battery 11 and a second battery 12. The first battery 11 and the second battery 12 are configured to be connectable to each other. The junction block 20 is an example of a vehicle connection circuit, and is interposed between the first battery 11, the second battery 12, and the motor 40, and electrically connects the first battery 11, the second battery 12, and the motor 40.

[0020] FIGS. 2 to 4 are diagrams showing an example of the circuit configuration of the vehicle battery structure 100 according to the present embodiment. The circuit configurations of FIGS. 2 to 4 are the same. FIG. 2 shows a first path 51 (thick line), FIG. 3 shows a second path 52 (thick line), and FIG. 4 shows a third path 53 (thick line). The dotted arrows in FIGS. 2 to 4 indicate the direction in which the current flows.

[0021] As shown in FIGS. 2 to 4, when rapidly charging using the DC inlet 68, the junction block 20 is connected to the DC inlet 68 for rapidly charging the first battery 11 and the second battery 12. On the other hand, when normally charging using the 2-in-1 charger 60, the junction block 20 is connected to the solar panel 64 and the auxiliary battery 65 for normally charging the first battery 11 and the second battery 12 via the 2-in-1 charger 60. Further, the junction block 20 may be connected to a wiring plug connector (so-called AC100V outlet) 66 or an AC inlet 67 for charging the first battery 11 and the second battery 12 via the 2-in-1 charger 60. The 2-in-1 charger 60 includes a filter 61, a DC-DC converter 62, and an OBC (On-board Battery Charger) 63. The DC-DC converter 62 is connected to the solar panel 64 and the auxiliary battery 65, and converts the DC voltage supplied from the solar panel 64 and the auxiliary battery 65 into a predetermined DC voltage corresponding to the first battery 11 and the second battery 12. The OBC 63 is connected to the wiring plug connector 66 or the AC inlet 67, and converts the AC voltage supplied from the wiring plug connector 66 or the AC inlet 67 into a predetermined DC voltage corresponding to the first battery 11 and the second battery 12. Each of the DC-DC converter 62 and the OBC 63 is connected to the junction block 20.

[0022] The junction block 20 includes a positive-side system main relay 21, a first current sensor 22, a first DC relay 23, a first fuse 24, a DC fuse 25, a second DC relay 26, a second current sensor 27, a second fuse 28, a third DC relay 29, a third fuse 30, a negative-side system main relay 31, a limiting resistor 32, a pre-charge-side system main relay 33, an AC fuse 34, a positive-side system sub-relay 35, a fourth DC relay 36, a fifth DC relay 37, and a voltage sensor 38.

[0023] One end of wiring W1 is connected to the positive side of DC inlet 68, and the other end is connected to wiring W2 via contact P1. One end of wiring W2 is connected to motor 40, and the other end is connected to the positive side of first battery 11. One end of wiring W3 is connected to the negative side of first battery 11, and the other end is connected to wiring W5 via contact P4. One end of wiring W4 is connected to wiring W3 via contact P3, and the other end is connected to wiring W6 via contact P5. One end of wiring W5 is connected to motor 40, and the other end is connected to the positive side of second battery 12. One end of wiring W6 is connected to the negative side of second battery 12, and the other end is connected to motor 40. One end of wiring W7 is connected to the negative side of DC inlet 68, and the other end is connected to wiring W6 via contact P6. One end of wiring W8 is connected to the positive side of OBC63, and the other end is connected to wiring W1 via contact P8. One end of wiring W9 is connected to the negative side of OBC63, and the other end is connected to wiring W7 via contact P9. One end of wiring W10 is connected to the positive side of DCDC converter 62 and the positive side of OBC63, and the other end is connected to wiring W2 via contact P2. One end of wiring W11 is connected to the negative side of DCDC converter 62 and the negative side of OBC63, and the other end is connected to wiring W6 via contact P7.

[0024] The junction block 20 according to this embodiment includes a first path 51 (shown by a thick line in Figure 2), a second path 52 (shown by a thick line in Figure 3), and a third path 53 (shown by a thick line in Figure 4). The first path 51 is a path that charges only the first battery 11 from the DC inlet 68 and passes through wirings W1, W2, W3, W4, W6, and W7. The second path 52 is a path that charges only the second battery 12 from the DC inlet 68 and passes through wirings W1, W2, motor 40, and wirings W5, W6, and W7. The third path 53 is a path that charges both the first battery 11 and the second battery 12 from the DC inlet 68 and passes through wirings W1, W2, W3, W5, W6, and W7.

[0025] The positive-side system main relay 21 is positioned between contact P1 of wiring W1 and contact P2 of wiring W2, and switches between the first path 51 and the second path 52. The first current sensor 22 is positioned between the negative side of the first battery 11 of wiring W3 and contact P3, and measures the current flowing through the first path 51 or the third path 53. The first DC relay 23 is positioned between contact P3 of wiring W3 and the first fuse 24 of wiring W4, and switches between the first path 51 and the third path 53. The first fuse 24 is positioned between the first DC relay 23 and contact P5 of wiring W4. The DC fuse 25 is positioned between contact P3 of wiring W3 and the second DC relay 26. The second DC relay 26 is positioned between the DC fuse 25 of wiring W3 and contact P4, and switches between the first path 51 and the third path 53. The second current sensor 27 is located between contact P4 of wiring W5 and the positive side of the second battery 12, and measures the current flowing through the second path 52 or the third path 53. The second fuse 28 is located between contact P4 of wiring W5 and the third DC relay 29. The third DC relay 29 is located between the second fuse 28 of wiring W5 and the motor 40, and switches between the first path 51 and the second path 52. The third fuse 30 is located between contact P5 of wiring W6 and the negative side system main relay 31. The negative side system main relay 31 is located between the third fuse 30 of wiring W6 and contact P7, and switches the first path 51, the second path 52, and the third path 53 on / off. The limiting resistor 32 and the precharge side system main relay 33 are connected in parallel with the negative side system main relay 31, forming a precharge circuit. The AC fuse 34 is located between the positive side system sub-relay 35 of wiring W10 and contact P2. The positive-side system sub-relay 35 is located between the AC fuse 34 of wiring W10 and the positive side of the DC-DC converter 62 and OBC 63, and switches the connection / disconnection with the 2-in-1 charger 60. The fourth DC relay 36 is located between contacts P9 and P6 of wiring W7, and switches the connection / disconnection with the DC inlet 68. The fifth DC relay 37 is located between contacts P1 and P8 of wiring W1, and switches the connection / disconnection with the DC inlet 68.The voltage sensor 38 is placed between wiring W1 and wiring W7 and measures the voltage between wiring W1 and wiring W7.

[0026] The second current sensor 27 in this embodiment is an example of a current sensor, and as shown in Figures 2 and 3, it is installed in the area where the second path 52 and the third path 53 overlap but do not overlap with the first path 51, and measures the current flowing through the second battery 12. More specifically, the second current sensor 27 is positioned between the confluence point of the second path 52 and the third path 53 and the positive side of the second battery 12. The confluence point of the second path 52 and the third path 53 is contact P4. The area where the second path 52 and the third path 53 overlap may be, for example, the area between contact P4 and endpoint E2 of the junction block 20. Endpoint E2 is connected to the positive side of the second battery 12. The first current sensor 22 is another example of a current sensor, and is installed in the area where the first path 51 and the third path 53 overlap but do not overlap with the second path 52, and measures the current flowing through the first battery 11. More specifically, the first current sensor 22 is positioned between the negative side of the first battery 11 and the branching point between the first path 51 and the third path 53. The branching point between the first path 51 and the third path 53 is contact P3. The overlapping portion of the first path 51 and the third path 53 may be, for example, the portion between contact P3 and endpoint E1 of the junction block 20. Endpoint E1 is connected to the negative side of the first battery 11. Furthermore, the first DC relay 23 is provided in the first path 51 at a position that does not overlap with the second path 52 and the third path 53, and the second DC relay 26 is provided in the third path 53 at a position that does not overlap with the first path 51 and the second path 52. The first DC relay 23 is an example of a relay, and the second DC relay 26 is another example of a relay. The second current sensor 27 measures the short-circuit current caused by a malfunction of the second DC relay 26 when the first battery 11 and the second battery 12 are connected in parallel, and measures the short-circuit current caused by a malfunction of the first DC relay 23 when the first battery 11 and the second battery 12 are connected in series.

[0027] Here, we consider the case where the first battery 11 and the second battery 12 are connected in parallel. In this case, current flows through the first path 51 shown in Figure 2 and the second path 52 shown in Figure 3, and the first battery 11 and the second battery 12 are charged in parallel. When the first battery 11 and the second battery 12 are being charged in parallel, the second DC relay 26 is off, and the current measured by the first current sensor 22 and the current measured by the second current sensor 27 are approximately the same. On the other hand, if the second DC relay 26 is accidentally turned on during charging, a short-circuit current path 54 is formed, as shown in Figures 2 and 3. The second current sensor 27 can measure the current in the short-circuit current path 54. In other words, if the second DC relay 26 malfunctions, a short-circuit current path 54 is formed, so the current measured by the first current sensor 22 and the current measured by the second current sensor 27 will be different. This makes it possible to detect the malfunction of the second DC relay 26. It is also possible to detect a malfunction of the second DC relay 26 using only the second current sensor 27. In this case, it is sufficient to detect the sudden change in current caused by the short-circuit current path 54.

[0028] Next, let's consider the case where the first battery 11 and the second battery 12 are connected in series. In this case, current flows through the third path 53 shown in Figure 4, and the first battery 11 and the second battery 12 are charged in series. When the first battery 11 and the second battery 12 are being charged in series, the first DC relay 23 is off, and the current measured by the first current sensor 22 and the current measured by the second current sensor 27 are approximately the same. On the other hand, if the first DC relay 23 is accidentally turned on during charging, a short-circuit current path 54 is formed, as shown in Figure 4. The second current sensor 27 can measure the current in the short-circuit current path 54. In other words, if the first DC relay 23 malfunctions, a short-circuit current path 54 is formed, so the current measured by the first current sensor 22 and the current measured by the second current sensor 27 will be different. This makes it possible to detect the malfunction of the first DC relay 23. It is also possible to detect the malfunction of the first DC relay 23 using only the second current sensor 27. In this case, it is sufficient to detect the sudden change in current caused by the short-circuit current path 54.

[0029] Here, the dotted line shows a hypothetical configuration where the second current sensor 27 is positioned on the second fuse 28 side of contact P4. When the second current sensor 27 is positioned as shown by the dotted line, it is not possible to measure the current in the short-circuit current path 54. Therefore, it is not possible to detect malfunctions of the second DC relay 26 and the first DC relay 23. In contrast, the second current sensor 27 in this embodiment is positioned between contact P4 and endpoint E2, so it is possible to measure the current in the short-circuit current path 54. As a result, it is possible to detect relay malfunctions whether the first battery 11 and the second battery 12 are connected in parallel or in series.

[0030] Figure 5 shows the circuit configuration of a modified vehicle battery structure 100A. For the sake of clarity, the first path 51, the second path 52, and the third path 53 are omitted from the illustration in Figure 5. As shown in Figure 5, the modified vehicle battery structure 100A includes a junction block 20A. The junction block 20A and the junction block 20 (see Figures 2 to 4) have different placements for the first current sensor 22 and the second current sensor 27. The second current sensor 27 is located in the area where the second path 52 and the third path 53 overlap, but not the first path 51, and measures the current flowing through the second battery 12. More specifically, the second current sensor 27 is located between the negative side of the second battery 12 and the confluence point of the first path 51 and the second path 52. The confluence point of the first path 51 and the second path 52 is contact P5. Furthermore, the overlapping portion of the second path 52 and the third path 53 may be, for example, the portion between contact P5 and endpoint E4 of the junction block 20. Endpoint E4 is connected to the negative side of the second battery 12. The first current sensor 22 is installed in the portion where the first path 51 and the third path 53 overlap, but not with the second path 52, and measures the current flowing through the first battery 11. More specifically, the first current sensor 22 is positioned between contact P2 of the wiring W2 and the positive side of the first battery 11. The overlapping portion of the first path 51 and the third path 53 may be, for example, the portion between contact P2 and endpoint E3 of the junction block 20. Endpoint E3 is connected to the positive side of the first battery 11.

[0031] If the second current sensor 27 were placed on the third fuse 30 side of contact P5, it would be impossible to measure the current in the short-circuit current path 54. Therefore, it would be impossible to detect malfunctions of the second DC relay 26 and the first DC relay 23. In contrast, the modified second current sensor 27 is placed between contact P5 and endpoint E4, so it can measure the current in the short-circuit current path 54. As a result, it is possible to detect relay malfunctions whether the first battery 11 and the second battery 12 are connected in parallel or in series.

[0032] Thus, according to this embodiment, in a vehicle equipped with multiple batteries, a relay malfunction can be detected using the minimum necessary current sensor.

[0033] The technical scope of this disclosure is not limited to the embodiments described above. Various modifications or improvements can be made to the embodiments without departing from the spirit, and such modified or improved forms are also included within the technical scope of this disclosure. [Explanation of Symbols]

[0034] 11. Battery No. 1 12 Second Battery 20 Junction Blocks 22 First current sensor 23. 1st DC Relay 26. 2nd DC Relay 27. Second current sensor 40 motors 51 First Route 52 Second Route 53 Third Route 100 Vehicle Battery Structure 200 vehicles

Claims

1. A vehicle connection circuit interposed between a first battery and a second battery, which are installed in a vehicle and configured to be connectable to each other, and a motor, which electrically connects the first battery, the second battery, and the motor, A first path for charging only the first battery, A second path that charges only the second battery, A third path for charging the first battery and the second battery, A current sensor is provided in the portion where the second path and the third path overlap, but do not overlap with the first path, and measures the current flowing through the second battery. Vehicle connection circuit including.

2. The current sensor is positioned between the confluence point of the second path and the third path and the positive side of the second battery, or between the negative side of the second battery and the confluence point of the first path and the second path. The vehicle connection circuit according to claim 1.

3. The system further includes another current sensor, which is provided in the portion where the first path and the third path overlap but do not overlap with the second path, and which measures the current flowing through the first battery. The vehicle connection circuit according to claim 1.

4. A relay is provided in the first path at a position that does not overlap with the second and third paths. In the third path, another relay is provided at a position that does not overlap with the first path and the second path. The current sensor measures the short-circuit current caused by a malfunction of the other relay when the first battery and the second battery are connected in parallel, and measures the short-circuit current caused by a malfunction of the relay when the first battery and the second battery are connected in series. The vehicle connection circuit according to claim 1.

5. First battery and A second battery configured to be connectable to the first battery, A vehicle connection circuit according to any one of claims 1 to 4, interposed between the first battery and the second battery and the motor, and electrically connecting the first battery, the second battery and the motor, A vehicle battery structure equipped with the following features.

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