Vehicle connection circuit, vehicle connection method, and vehicle battery structure

Abstract

In vehicles equipped with multiple batteries, this system reduces power consumption while also supporting AC charging. [Solution] The junction block 20 is interposed between the first battery 11 and the second battery 12 and the motor 40, electrically connecting the first battery 11, the second battery 12, and the motor 40. The junction block 20 includes a first path 51, a second path 52, a third path 53, a positive-side system main relay 21, wiring W10 connecting the positive side of the first battery 11 and the positive-side system main relay 21 and the positive sides of the DCDC converter 62 and OBC 63 respectively, a positive-side system sub-relay 35, a negative-side system main relay 31, wiring W11 connecting the downstream side of the negative-side system main relay 31 and the negative sides of the DCDC converter 62 and OBC 63 respectively.

Description

Technical Field

[0001] The present disclosure relates to a vehicle connection circuit, a vehicle connection method, 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, not only charging from a DC inlet but also charging from an AC power source and charging from a solar panel (hereinafter, these are collectively referred to as "AC charging etc.") are supported. In this case, if dedicated relays are provided on both the positive side and the negative side to support AC charging etc., the power consumption will increase.

[0005] An object of the present disclosure is to provide a vehicle connection circuit, a vehicle connection method, and a vehicle battery structure that can support AC charging etc. while reducing power consumption in a vehicle equipped with a plurality of batteries.

Means for Solving the Problems

[0006] It should be noted that there seems to be a misspelling in the original text where "

発明が解決しようとする課題

発明が解決しようとする課題

Problems to be Solved by the Invention

[0007] The vehicle connection circuit according to claim 1 can reduce power consumption while also supporting AC charging in a vehicle equipped with multiple batteries. Specifically, the positive sides of the DC-DC converter and the on-board charger are branched upstream of the first system relay, and the negative sides of the DC-DC converter and the on-board charger are connected downstream of the third system relay. In other words, by having the third system relay perform the function of the negative system relay corresponding to the positive second system relay, the number of negative system relays can be reduced. As a result, voltage can be applied only to the necessary paths using only the second system relay on one side (positive pole), thus reducing power consumption.

[0008] The vehicle connection circuit according to claim 2 includes a pre-charge circuit connected in parallel with the third system relay in the vehicle connection circuit according to claim 1, wherein the pre-charge circuit has a limiting resistor and a fourth system relay connected in series.

[0009] In the vehicle connection circuit according to claim 2, the capacitors of the DC-DC converter and the on-board charger can be pre-charged using the pre-charge circuit.

[0010] The vehicle connection circuit according to claim 3 is the vehicle connection circuit according to claim 1, wherein the DC-DC converter is connected to a solar panel, and the on-board charger is connected to a wiring plug connector.

[0011] The vehicle connection circuit according to claim 3 can support charging from a solar panel and charging from a wiring plug connector.

[0012] The vehicle connection method according to claim 4 is a vehicle connection method using a vehicle connection circuit according to any one of claims 1 to 3, wherein the third system relay is connected first, and then the second system relay is connected.

[0013] The vehicle connection method according to claim 4 can reduce the electrical load when the second system relay is activated.

[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 3, which is interposed between the first battery and the second battery and a DC charger, a DC-DC converter, an on-board charger, and a motor, and electrically connects the first battery, the second battery, and the motor.

[0015] The vehicle battery structure according to claim 5 allows for reduced power consumption and support for AC charging, etc., in a vehicle equipped with multiple batteries. [Effects of the Invention]

[0016] As explained above, this disclosure makes it possible to reduce power consumption while also supporting AC charging in a vehicle equipped with multiple batteries. [Brief explanation of the drawing]

[0017] [Figure 1] This block diagram shows an example of the configuration of a vehicle battery structure mounted on a vehicle according to the embodiment. [Figure 2] This figure shows an example of the circuit configuration of a vehicle battery structure according to the embodiment. [Figure 3] This figure shows an example of the circuit configuration of a vehicle battery structure according to the embodiment. [Figure 4] This figure shows an example of the circuit configuration of a vehicle battery structure according to the embodiment. [Figure 5] This figure shows an example of a drive sequence when precharging the capacitor of the DC-DC converter according to the embodiment. [Modes for carrying out the invention]

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

[0019] Figure 1 is a block diagram showing an example of the configuration of a vehicle battery structure 100 mounted on a vehicle 200 according to this embodiment. As shown in Figure 1, the vehicle 200 according to this embodiment is equipped with a vehicle battery structure 100 and a motor 40 that drives the vehicle 200. The vehicle battery structure 100 comprises a battery 10 and a junction block 20, and the battery 10 comprises 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 and the second battery 12 and the motor 40, electrically connecting the first battery 11, the second battery 12, and the motor 40.

[0020] Figures 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 Figures 2 to 4 are the same. Figure 2 shows the first path 51 (thick line), Figure 3 shows the second path 52 (thick line), and Figure 4 shows the third path 53 (thick line). The dotted arrows in Figures 2 to 4 indicate the direction of current flow. The junction block 20 is interposed between the first battery 11 and the second battery 12, and the DC inlet 68, the DC-DC converter 62, and the OBC (On-board Battery Charger) 63.

[0021] As shown in Figures 2 to 4, when performing rapid 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. The DC inlet 68 is an example of a DC charger. On the other hand, when performing normal 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 the wiring plug connector (so-called AC100V outlet) 66 or the 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 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 an example of an in-vehicle charger, and 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 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 system main relay 31, a limiting resistor 32, a precharge system main relay 33, an AC fuse 34, a positive system sub-relay 35, a fourth DC relay 36, a fifth DC relay 37, and a voltage sensor 38. Note that the positive system main relay 21 is an example of a first system relay, the positive system sub-relay 35 is an example of a second system relay, the negative system main relay 31 is an example of a third system relay, and the precharge system main relay 33 is an example of a fourth system relay.

[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. Note that wiring W10 is an example of positive side wiring, and wiring W11 is an example of negative side wiring.

[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 (AC charging, etc.) from at least one of the DCDC converter 62 and the OBC 63, and is a path that passes through wiring W10, W2, W3, W4, W6, and W11. The second path 52 is a path that charges only the second battery 12 (AC charging, etc.) from at least one of the DCDC converter 62 and the OBC 63, and is a path that passes through wiring W10, W2, the motor 40, and wiring W5, W6, and W11. The third path 53 is a path for charging the first battery 11 and the second battery 12 (AC charging, etc.) from at least one of the DC-DC converter 62 and the OBC 63, and is a path that passes through wiring W10, W2, W3, W5, W6, and W11.

[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 to form a precharge circuit. The limiting resistor 32 and the precharge side system main relay 33 that constitute the precharge circuit are connected in series. The AC fuse 34 is located between the positive side system sub-relay 35 and contact P2 of wiring W10. 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 contact P9 and contact P6 of wiring W7, and switches the connection / disconnection with the DC inlet 68.The fifth DC relay 37 is positioned between contacts P1 and P8 of wiring W1 and switches the connection / disconnection of the DC inlet 68. The voltage sensor 38 is positioned between wiring W1 and wiring W7 and measures the voltage between wiring W1 and wiring W7.

[0026] As shown in Figures 2 to 4, the junction block 20 according to this embodiment includes a positive system main relay 21, wiring W10, a positive system sub-relay 35, a negative system main relay 31, and wiring W11. The positive system main relay 21 is located closer to the motor 40 than the branching point (contact P2 in this case) between the first path 51 and the second path 52 in the second path 52. Wiring W10 connects the positive side of the first battery 11 and the positive system main relay 21 (contact P2 in this case) to the positive sides of the DCDC converter 62 and the OBC 63, and is isolated from the charging path of the DC inlet 68. The positive system sub-relay 35 is located on wiring W10. The negative system main relay 31 is located where the first path 51, the second path 52, and the third path 53 overlap, and shares the intermittent connection of the charging path of the DC inlet 68. Wiring W11 connects the downstream side of the negative-side system main relay 31 (contact P7 in this case) to the negative sides of the DC-DC converter 62 and OBC 63, respectively.

[0027] In other words, according to this embodiment, the positive side of the 2-in-1 charger 60 is branched upstream (contact P2) of the positive system main relay 21, and the negative side of the 2-in-1 charger 60 is connected downstream (contact P7) of the negative system main relay 31. Therefore, by simply providing a single-pole (positive) positive system sub-relay 35 in the wiring W10, voltage can be applied only to the necessary paths when charging from an AC power source or a solar panel. In other words, the negative system main relay 31 can perform the function of the negative system sub-relay corresponding to the positive system sub-relay 35, thereby reducing the number of negative system sub-relays. The negative system main relay 31 is common to both AC charging and DC charging using the DC inlet 68. This allows for reduced power consumption while also supporting AC charging.

[0028] If the function of the positive system sub-relay 35 were to be transferred to the positive system main relay 21, that is, if the positive system sub-relay 35 were eliminated, the number of times the positive system main relay 21 operates during AC charging, etc., would increase, efficiency would decrease, and the heat dissipation cost of the junction block 20 would increase. Also, if the wiring W10 were connected downstream of the positive system main relay 21, the number of relays would increase during AC charging, etc., and efficiency would decrease. Furthermore, if the positive system main relay 21 were to be used in place of the negative system main relay 31, the number of relays would increase during AC charging, etc. In addition, since the positive system main relay 21 does not have a pre-charge circuit connected to it, pre-charging of the capacitors in the 2-in-1 charger 60 (the primary capacitors of the DC-DC converter 62 and OBC 63) would be required.

[0029] In contrast, according to this embodiment, as described above, the positive side of the 2-in-1 charger 60 is branched upstream (contact P2) of the positive system main relay 21, and the negative side of the 2-in-1 charger 60 is connected downstream (contact P7) of the negative system main relay 31. This makes it possible to precharge the capacitors (primary side capacitors of the DC-DC converter 62 and OBC 63) of the 2-in-1 charger 60 using the precharge circuit connected to the negative system main relay 31. Furthermore, there is no need to make the DC-DC converter 62 bidirectional, and the load on the positive system sub-relay 35 is reduced.

[0030] Furthermore, if the negative side of the 2-in-1 charger 60 were connected to the upstream side of the negative system main relay 31, the high-voltage second battery 12 and the 2-in-1 charger 60 would always be connected. For example, if the connector of the 2-in-1 charger 60 were damaged during a collision and a short circuit occurred, there is a risk that the insulation of the second battery 12 would also deteriorate. In contrast, according to this embodiment, the negative side of the 2-in-1 charger 60 is connected to the downstream side of the negative system main relay 31, so the second battery 12 can be disconnected by the negative system main relay 31.

[0031] Figure 5 shows an example of a drive sequence when precharging the capacitor of the DC-DC converter 62 according to this embodiment. In Figure 5, IB represents current and VH represents voltage. As shown in Figure 5, when precharging the capacitor of the DC-DC converter 62, it is desirable to connect the negative system main relay 31 first and then the positive system sub-relay 35. When the positive system sub-relay 35 is connected, an electrical load corresponding to the inrush current is applied to the contacts, which affects its lifespan. However, by connecting the negative system main relay 31 before the positive system sub-relay 35, the electrical load during operation can be prevented from being applied to the contacts.

[0032] Thus, according to this embodiment, in a vehicle equipped with multiple batteries, power consumption can be reduced while also supporting AC charging and the like.

[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 21. Positive side system main relay (first system relay) 31. Negative side system main relay (3rd system relay) 32 limiting resistor 33. Pre-charge side system main relay (4th system relay) 35. Positive side system sub-relay (second system relay) 40 motors 51 First Route 52 Second Route 53 Third Route 62 DC-DC converters 63 OBC (on-vehicle charger) 64 solar panels 66 Wiring connectors 200 vehicles W10 Wiring (Positive Wiring) W11 Wiring (Negative Wiring)

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, a DC charger, a DC-DC converter, an on-board charger, and a motor, which electrically connects the first battery, the second battery, and the motor, A first path for charging only the first battery from at least one of the DC-DC converter and the on-board charger, A second path for charging only the second battery from at least one of the DC-DC converter and the on-board charger, A third path for charging the first battery and the second battery from at least one of the DC-DC converter and the on-board charger, A first system relay is provided in the second path, closer to the motor than the branching point between the first path and the second path, A positive wire is connected between the positive side of the first battery and the first system relay, and between the positive sides of the DC-DC converter and the on-board charger, and is separated from the charging path of the DC charger. A second system relay is provided on the positive side wiring, A third system relay is provided in the portion where the first path, the second path, and the third path overlap, and which shares the interruption of the charging path of the DC charger. A negative wiring that connects the downstream side of the third system relay to the negative sides of the DC-DC converter and the in-vehicle charger, Vehicle connection circuit including.

2. Includes a pre-charge circuit connected in parallel with the third system relay, The aforementioned pre-charge circuit has a limiting resistor and a fourth system relay connected in series. The vehicle connection circuit according to claim 1.

3. The aforementioned DC-DC converter is connected to the solar panel, The in-vehicle charger is connected to a wiring plug connector. The vehicle connection circuit according to claim 1.

4. A vehicle connection method using a vehicle connection circuit according to any one of claims 1 to 3, Connect the third system relay, then connect the second system relay. Vehicle connection method.

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 3, which is interposed between the first battery and the second battery, a DC charger, a DC-DC converter, an on-board charger, and a motor, and electrically connects the first battery, the second battery, and the motor. A vehicle battery structure equipped with the following features.

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