Electric-powered vehicle

Abstract

To provide a technique that can achieve a plurality of circuit structures, with no need of two boost converters.SOLUTION: An electric-powered vehicle comprises: a battery; an electric-powered unit; a boost converter; a charging inlet; and a connection circuit including a plurality of relays, through which the battery. the electric-powered unit, the boost converter and the charging inlet are electrically connected to one another. The connection circuit can alternatively form a power-running circuit structure, a low-voltage charging circuit structure and a high-voltage charging circuit structure, by switching the plurality of relays. In the power-running circuit structure, the battery is electrically connected to the electric-powered unit through the boost converter. In the low-voltage charging circuit structure, the charging inlet is electrically connected to the battery through the boost converter and the electric-powered unit is electrically shut off from the boost converter. In the high-voltage charging circuit structure, the charging inlet is electrically connected to the battery without interposing the boost converter therebetween and the electric-powered unit is electrically shut off from the boost converter.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The technology disclosed in this specification relates to electric vehicles. [Background technology]

[0002] Patent document 1 describes a vehicle equipped with a rechargeable battery, an electric unit including a driving motor, a charging inlet detachably connected to an external charging device, a first boost converter that boosts the power supplied from the battery to the electric unit, a second boost converter that boosts the power supplied from the charging device to the battery, and a connection circuit that includes a relay and electrically connects the battery, the electric unit, the first boost converter, the second boost converter, and the charging inlet. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-054145 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the electric vehicle of Patent Document 1, the connection circuit can selectively form a powering circuit structure, a low-voltage charging circuit structure, and a high-voltage charging circuit structure by switching the relay. In the powering circuit structure, the battery is electrically connected to the electric unit via a first boost converter. In the low-voltage charging circuit structure, the charging inlet is electrically connected to the battery via a second boost converter. In the high-voltage charging circuit structure, the charging inlet is electrically connected to the battery without going through the second boost converter. Thus, in the electric vehicle of Patent Document 1, it is necessary to separately provide a first boost converter that boosts the voltage supplied from the battery to the electric unit, and a second boost converter that boosts the power supplied from the charging inlet to the battery.

[0005] This specification provides a technique that can realize the above-mentioned multiple circuit structures without requiring two boost converters. [Means for solving the problem]

[0006] In a first aspect disclosed in this specification, an electric vehicle includes a rechargeable battery, an electric unit including a traction motor, a boost converter, a charging inlet detachably connected to an external charging device, and a connection circuit including a plurality of relays and electrically connecting the battery, the electric unit, the boost converter, and the charging inlet. The connection circuit is capable of selectively forming a powering circuit structure, a low-voltage charging circuit structure, and a high-voltage charging circuit structure by switching the plurality of relays. In the powering circuit structure, the battery is electrically connected to the electric unit via the boost converter, in the low-voltage charging circuit structure, the charging inlet is electrically connected to the battery via the boost converter and the electric unit is electrically disconnected from the boost converter, and in the high-voltage charging circuit structure, the charging inlet is electrically connected to the battery not via the boost converter and the electric unit is electrically disconnected from the boost converter.

[0007] According to the above configuration, the boost converter is used to boost the power supplied from the battery to the electric unit, and is also used to boost the power supplied from the charging inlet to the battery. That is, the boost converter is used both during powering and charging. According to such a configuration, the above-mentioned multiple circuit structures can be realized without the need for two boost converters. As a result, the electric vehicle can be made more compact. [Brief description of the drawings]

[0008] [Figure 1] 1 shows a schematic diagram of an electric vehicle 2 according to a first embodiment. [Diagram 2] The switching process executed by the control device 20 will be described. [Diagram 3]1 shows a schematic diagram of an electric vehicle 102 according to a second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] (First embodiment) 1, the electric vehicle 2 includes a rechargeable battery 10, an electric unit 12, a boost converter 14, a charging inlet 16, a connection circuit 18, and a control device 20. The battery 10 is a rechargeable secondary battery, and includes, as an example, multiple lithium-ion cells.

[0010] The electric unit 12 has an inverter 30 and a traction motor 32. The inverter 30 converts DC power into AC power and drives the traction motor 32. The traction motor 32 is driven by the power supplied from the inverter 30 and transmits driving force to the drive wheels. The boost converter 14 is a device that boosts electric power. The boost converter 14 has a single-phase structure. The charging inlet 16 is detachably connected to an external charging device (not shown) and receives charging power from the external charging device.

[0011] The connection circuit 18 includes a first power line L1 to an eighth power line L8 and a first relay R1 to a fourth relay R4. The first power line L1 and the second power line L2 electrically connect the battery 10 and the boost converter 14. The third power line L3 and the fourth power line L4 electrically connect the boost converter 14 and the electric unit 12 (specifically, the inverter 30). The fifth power line L5 electrically connects the charging inlet 16 and the first power line L1. The sixth power line L6 electrically connects the charging inlet 16 and the second power line L2. The seventh power line L7 connects the first power line L1 and the third power line L3. The first connection part C1, which is a connection part between the first power line L1 and the seventh power line L7, is provided on the battery 10 side relative to the second connection part C2, which is a connection part between the first power line L1 and the fifth power line L5. The eighth power line L8 connects the second power line L2 and the fourth power line L4. The third connection point C3, which is the connection point between the second power line L2 and the eighth power line L8, is provided closer to the battery 10 than the fourth connection point C4, which is the connection point between the second power line L2 and the sixth power line L6.

[0012] The first relay R1 is provided on the first power line L1 and the second power line L2. The first relay R1 is provided on the battery 10 side of the first connection part C1 and on the battery 10 side of the third connection part C3. The first relay R1 is a so-called system main relay. The second relay R2 is provided on the first power line L1 and the second power line L2. The second relay R2 is provided between the first connection part C1 and the second connection part C2 and between the third connection part C3 and the fourth connection part C4. The third relay R3 is provided on the seventh power line L7 and the eighth power line L8. The fourth relay R4 is provided on the third power line L3 and the fourth power line L4. The fourth relay R4 is provided on the electric unit 12 side of the fifth connection point C5, which is the connection point between the third power line L3 and the seventh power line L7, and on the electric unit 12 side of the sixth connection point C6, which is the connection point between the fourth power line L4 and the eighth power line L8.

[0013] The control device 20 is a computer equipped with a CPU, a ROM, and a RAM. The control device 20 controls the operations of the battery 10, the electric unit 12, the boost converter 14, and the first relay R1 to the fourth relay R4. The control device 20 can selectively form a powering circuit structure (see FIG. 1(A)), a low-voltage charging circuit structure (see FIG. 1(B)), and a high-voltage charging circuit structure (see FIG. 1(C)) by switching the first relay R1 to the fourth relay R4.

[0014] (Connection circuit switching process; Figure 2) The connection circuit switching process executed by the control device 20 of the electric vehicle 2 will be described with reference to Fig. 2. The control device 20 periodically executes the connection circuit switching process.

[0015] In S10, the control device 20 determines whether or not an external charging device is connected to the charging inlet 16. If the charging device is not connected to the charging inlet 16 (NO in S10), the control device 20 proceeds to S12. On the other hand, if the charging device is connected to the charging inlet 16 (YES in S10), the control device 20 proceeds to S20.

[0016] In S12, the control device 20 causes the connection circuit 18 to form a powering circuit structure. As shown in FIG. 1(A), the control device 20 electrically connects the first relay R1, the second relay R2, and the fourth relay R4, and electrically opens the third relay R3. This electrically connects the battery 10 to the electric unit 12 via the boost converter 14. In FIG. 1(A), the direction of the current flowing from the battery 10 to the electric unit 12 is indicated by a solid arrow, and the direction of the current flowing from the electric unit 12 to the battery 10 is indicated by a dashed arrow. Therefore, the power supplied from the battery 10 is supplied to the electric unit 12 via the boost converter 14. When S12 ends, the control device 20 ends the processing of FIG. 2.

[0017] In S20, the control device 20 judges whether or not the battery voltage of the battery 10 is greater than the output voltage of the charging device. If the battery voltage is greater than the output voltage (YES in S20), the control device 20 proceeds to S22. On the other hand, if the battery voltage is equal to or less than the output voltage (NO in S20), the control device 20 proceeds to S24. An example of a case where the control device 20 judges YES in S20 is when the battery voltage is 800V and the output voltage is 400V. An example of a case where the control device 20 judges NO in S20 is when the battery voltage is 200V and the output voltage is 400V.

[0018] In S22, the control device 20 causes the connection circuit 18 to form a low-voltage charging circuit structure. As shown in FIG. 1B, the control device 20 electrically connects the first relay R1 and the third relay R3, and electrically opens the second relay R2 and the fourth relay R4. As a result, the charging inlet 16 is electrically connected to the battery 10 via the boost converter 14, and the electric unit 12 is electrically disconnected from the boost converter 14. In FIG. 1B, the direction of the current flowing from the charging inlet 16 to the battery 10 is indicated by a solid arrow, and the direction of the current flowing from the battery 10 to the charging inlet 16 is indicated by a dashed arrow. Therefore, the charging power supplied from the charging device is supplied to the battery 10 via the boost converter 14. That is, the power boosted by the boost converter 14 is supplied to the battery 10. When S22 ends, the control device 20 ends the processing of FIG. 2. Then, the processing for charging the battery 10 is executed.

[0019] In S24, the control device 20 causes the connection circuit 18 to form a high-voltage charging circuit structure. As shown in FIG. 1(C), the control device 20 electrically connects the first relay R1 and the second relay R2, and electrically opens the third relay R3 and the fourth relay R4. As a result, the charging inlet 16 is electrically connected to the battery 10 without passing through the boost converter 14, and the electric unit 12 is electrically disconnected from the boost converter 14. In FIG. 1(C), the direction of the current flowing from the charging inlet 16 to the battery 10 is indicated by a solid arrow, and the direction of the current flowing from the battery 10 to the charging inlet 16 is indicated by a dashed arrow. Therefore, the charging power supplied from the charging device is supplied to the battery 10 without passing through the boost converter 14. When S24 ends, the control device 20 ends the processing of FIG. 2. Then, the processing for charging the battery 10 is executed.

[0020] As described above, the electric vehicle 2 includes the rechargeable battery 10, the electric unit 12 including the traction motor 32, the boost converter 14, the charging inlet 16 that is detachably connected to an external charging device, and the connection circuit 18 that includes multiple relays R2 to R4 and electrically connects the battery 10, the electric unit 12, the boost converter 14, and the charging inlet 16. The connection circuit 18 is capable of selectively forming a powering circuit structure, a low-voltage charging circuit structure, and a high-voltage charging circuit structure by switching the multiple relays R2 to R4. In the powering circuit structure, the battery 10 is electrically connected to the electric unit 12 via the boost converter 14; in the low-voltage charging circuit structure, the charging inlet 16 is electrically connected to the battery 10 via the boost converter 14 and the electric unit 12 is electrically disconnected from the boost converter 14; and in the high-voltage charging circuit structure, the charging inlet 16 is electrically connected to the battery 10 without going through the boost converter 14 and the electric unit 12 is electrically disconnected from the boost converter 14.

[0021] According to the above configuration, boost converter 14 is used to boost the power supplied from battery 10 to electric unit 12, and is also used to boost the power supplied from charging inlet 16 to battery 10. That is, boost converter 14 is used both during powering and charging. According to such a configuration, the above-mentioned multiple circuit structures can be realized without the need for two boost converters. As a result, electric vehicle 2 can be made compact.

[0022] (Second Example) As shown in Fig. 3, the electric vehicle 102 of the second embodiment differs from the boost converter 14 of the first embodiment in that the boost converter 114 has a three-phase structure. The other points are similar to the electric vehicle 2 of the first embodiment. In this way, the boost converter 114 may have a multi-phase structure in which a plurality of boost circuits are connected in parallel, and can achieve the same effects as the first embodiment regardless of the number of phases. [Explanation of symbols]

[0023] 2: electric vehicle, 10: battery, 12: electric unit, 14: boost converter, 16: charging inlet, 18: connection circuit, 20: control device, 30: inverter, 32: driving motor, 102: electric vehicle, 114: boost converter

Claims

[Claim 1] An electric vehicle, A rechargeable battery; an electric unit including a driving motor; A boost converter; A charging inlet that is detachably connected to an external charging device; a connection circuit including a plurality of relays and electrically connecting the battery, the electric unit, the boost converter, and the charging inlet; Equipped with the connection circuit is capable of selectively forming a powering circuit structure, a low-voltage charging circuit structure, and a high-voltage charging circuit structure by switching the plurality of relays, In the powering circuit structure, the battery is electrically connected to the electric unit via the boost converter, In the low-voltage charging circuit structure, the charging inlet is electrically connected to the battery via the boost converter, and the electric unit is electrically isolated from the boost converter; In the high-voltage charging circuit structure, the charging inlet is electrically connected to the battery without passing through the boost converter, and the electric unit is electrically disconnected from the boost converter. Electric car.

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