Vehicle Power System

Abstract

To reduce an influence of electromagnetic noise on on-vehicle AV equipment when an electric vehicle is electrically charged.SOLUTION: A vehicle power supply system 2 has: a first battery 5 which supplies electric power to a rotary electric machine 3 of a vehicle 1; a second battery 6 which feeds electricity to AV equipment 4 mounted on the vehicle; a switching device which electrically disconnects the AV equipment, a second ground line of the second battery and a first ground line of the first battery in an external charging state in which the vehicle has the first battery charged from outside the vehicle; and a shield structure 14 which electromagnetically shields a first load circuit 24a which includes the rotary electric machine connected to the first battery or a second load circuit 24b including the AV equipment connected to the second battery from the other load circuit.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a vehicle power supply system that supplies power to an on-board device in a vehicle. [Background technology]

[0002] Patent Document 1 discloses the configuration of a charging port for an electric vehicle that uses a simple method to ground the cable. Patent Document 2 describes a charging cable for an electric vehicle that is composed of a current supply line, a ground line, and a shielded line, in which the ground line and shielded line are grounded on the charger side and the shielded line and grounded on the electric vehicle side to reduce radiated noise. Patent Document 3 describes a charging device that includes a vehicle body connection wire in the charging cable and detects a ground fault from the potential of the vehicle body connection wire. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-166756 [Patent Document 2] Patent No. 5048888 [Patent Document 3] Japanese Patent Application Publication No. 5-276674 Summary of the Invention [Problem to be solved by the invention]

[0004] When charging a secondary battery for powering an electric vehicle using high-capacity charging equipment at a charging station or the like, electromagnetic noise caused by a large charging current flowing through the secondary battery for powering the vehicle can disrupt viewing on in-vehicle AV equipment. An object of the present invention is to reduce the influence of electromagnetic noise on in-vehicle AV equipment when an electric vehicle is being charged. [Means for solving the problem]

[0005] One aspect of the present invention is a vehicle power supply system having a first battery that supplies power to a rotating electric machine of a vehicle, a second battery that supplies power to AV equipment mounted on the vehicle, a switching device that electrically disconnects a second ground line of the AV equipment and the second battery from a first ground line of the first battery when the vehicle is in an external charging state in which the first battery is being charged from outside the vehicle, and a shielding structure that electromagnetically shields one of a first load circuit including the rotating electric machine connected to the first battery and a second load circuit including the AV equipment connected to the second battery from the other load circuit. According to another aspect of the present invention, the switching device disconnects the electrical connection between the first ground line, which is grounded to the earth via the body of the vehicle, and the second ground line. According to another aspect of the present invention, the vehicle includes a battery socket for removably attaching at least one of the first battery and the second battery to the body of the vehicle, and the switching device disconnects the electrical connection between the first ground line and the second ground line by disconnecting the electrical connection between the ground line of the first battery and the ground line of the second battery in the battery socket. According to another aspect of the present invention, at least when the second ground line is electrically disconnected from the first ground line by the switching device, the AV equipment communicates with other equipment installed in the vehicle using a carrier that allows communication even when electrically isolated. [Effects of the Invention]

[0006] According to the present invention, it is possible to reduce the influence of electromagnetic noise on in-vehicle AV equipment when charging an electric vehicle. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a diagram showing the configuration of a vehicle power supply system according to a first embodiment of the present invention. [Figure 2]FIG. 5 is a diagram showing the configuration of a vehicle power supply system according to a second embodiment of the present invention. [Figure 3] FIG. 10 is a diagram showing the configuration of a vehicle power supply system according to a third embodiment of the present invention. [Figure 4] FIG. 10 is a diagram showing the configuration of a vehicle power supply system according to a fourth embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. [First embodiment] 1 is a diagram showing the configuration of a vehicle power supply system 2a mounted on a vehicle 1, which is an electric vehicle, according to a first embodiment of the present invention. The vehicle power supply system 2a includes a rotating electric machine 3 that drives the vehicle 1, AV equipment 4, a first battery 5 that supplies power to the rotating electric machine 3, a second battery 6 that supplies power to the AV equipment 4, an ECU 7 that controls various functions of the vehicle 1, and a switching control device 8a. The AV equipment 4 may be, for example, a television, communication equipment such as a TCU (Telematics Control Unit), a display audio, a radio device, an IVI (In-Vehicle Infotainment) device, etc.

[0009] The first battery 5 is charged by the rotating electric machine 3 when the rotating electric machine 3 operates in a generator mode by so-called regenerative braking, and is also charged by receiving power from a charging facility outside the vehicle 1 via a charging connector 9 provided on the body of the vehicle 1. The rotating electric machine 3 is provided with a drive device (not shown) that controls whether to generate driving force or to supply power generated by regenerative braking to the first battery 5.

[0010] A first ground line 10 (one of the thick lines in the figure) is connected between the rotating electric machine 3 and the first battery 5, and a second ground line 11 (the other of the thick lines in the figure) is connected between the AV equipment 4 and the second battery 6. The first ground line 10 is also connected to the ground of the ECU 7.

[0011] In this embodiment, the first ground line 10 is grounded to the earth via a vehicle body ground 12, which is a ground line formed by the body of the vehicle 1, and the second ground line 11 is connected to the first ground line 10 via a switching device 30a. The switching device 30a is, for example, a normally-on type relay, and when the switching device 30a is not energized, the first ground line 10 and the second ground line 11 are connected. Hereinafter, the switching device 30a and switching devices 30b, 30c, 30d, and 30e, which will be described later, will also be collectively referred to as switching devices 30.

[0012] In the embodiments described herein, the switching device 30 is a relay controlled by a switching control device 8a, 8b, or 8c (described later), but is not limited to this. As described later, the switching device 30 may be any electrical component, such as a mechanical switch, that can connect / disconnect the first ground line 10 and the second ground line 11.

[0013] When the vehicle 1 is in an external charging state in which the first battery 5 is being charged from outside the vehicle 1, the switching control device 8a controls the switching device 30 to electrically disconnect the second ground line between the AV equipment 4 and the second battery 6 from the first ground line 10 of the first battery 5.

[0014] The switching control device 8a includes a processor 20a and a memory 21. The memory 21 is configured, for example, by a volatile and / or non-volatile semiconductor memory and / or a hard disk drive. The processor 20a is, for example, a computer including a CPU (Central Processing Unit). The processor 20a may be configured to include a ROM (Read Only Memory) in which a program is written, a RAM (Random Access Memory) for temporarily storing data, and the like. The processor 20a includes, as functional elements or functional units, a detection unit 22 and a switching control unit 23a.

[0015] These functional elements of the processor 20a are realized, for example, by the processor 20a, which is a computer, executing a program. The computer program can be stored in any computer-readable storage medium. Alternatively, all or part of the functional elements of the processor 20a can be configured by hardware, each of which includes one or more electronic circuit components.

[0016] The detection unit 22 detects power supply to the first battery 5 from outside the vehicle 1 and detects that the vehicle 1 is in an external charging state in which the first battery 5 is being charged from outside the vehicle. For example, the detection unit 22 detects that the vehicle 1 is in an external charging state by a power supply sensor 13 provided between the first battery 5 and the charging connector 9. The power supply sensor 13 may be, for example, a current sensor that detects a current in a conductive cable between the first battery 5 and the charging connector 9. Alternatively, the power supply sensor 13 may be a mechanical sensor that detects that an external charging cable has been connected to the charging connector 9.

[0017] When the vehicle 1 is in an external charging state, the switching control unit 23a electrically disconnects the second ground line 11 from the first ground line 10. In this embodiment, the switching control unit 23a, for example, instructs the switching device 30a, which turns on and off the connection between the second ground line 11 and the first ground line 10, to electrically disconnect the connection between the second ground line 11 and the first ground line 10 when the vehicle 1 is in an external charging state.

[0018] The vehicle power supply system 2a also includes a shielding structure 14 that electromagnetically shields a second load circuit 24b including AV equipment 4 connected to a second battery 6 from a first load circuit 24a including a rotating electric machine 3 connected to a first battery 5. The shielding structure 14 does not need to be a sealed enclosure, and can be made of a conductive material having mesh, slits, and / or openings of a size corresponding to the wavelength of the electromagnetic waves to be shielded, in accordance with conventional technology.

[0019] In the vehicle power supply system 2a having the above configuration, when the vehicle 1 is in an external charging state, the second ground line 11 and the first ground line 10 are electrically disconnected, and the second load circuit 24b including the AV equipment 4 is electromagnetically shielded by the shield structure 14 from the first load circuit 24a including the rotating electric machine 3. Therefore, in the vehicle power supply system 2a, when the first battery 5 of the vehicle 1 is being charged by a large-capacity charging facility at a charging station or the like, the influence of electromagnetic noise caused by the large charging current flowing through the first battery 5 for power on the AV equipment 4 can be effectively reduced. Therefore, disturbances to viewing on the AV equipment 4 in the external charging state can be reduced.

[0020] Note that when the second ground line 11 is electrically disconnected from the first ground line 10, the ground potentials of the AV equipment 4 and the ECU 7 may differ, which may cause a disruption in electrical communication between them. For this reason, the AV equipment 4 and the ECU 7 may communicate using a carrier that allows communication even when they are electrically isolated, such as communication using light, sound, or vibration as a carrier that can maintain electrical isolation between the AV equipment 4 and the ECU 7. In this embodiment, communication between the AV equipment 4 and the ECU 7 is performed using light as a carrier, for example, via a photocoupler 15. Note that such communication using a carrier that can maintain electrical isolation does not need to be performed constantly between the AV equipment 4 and the ECU 7, and may be performed at least when the vehicle 1 is in an external charging state.

[0021] [Second embodiment] Fig. 2 is a diagram showing the configuration of a vehicle power supply system 2b according to a second embodiment of the present invention. In Fig. 2, the same components as those shown in Fig. 1 are designated by the same reference numerals as those shown in Fig. 1, and the explanation given in Fig. 1 above is incorporated herein.

[0022] Vehicle power supply system 2b has a similar configuration to vehicle power supply system 2a, but first ground line 10 and second ground line 11 are connected to vehicle body ground 12 via switching devices 30b and 30c, respectively. Switching devices 30b and 30c are, for example, normally-on type relays, similar to switching device 30a, and when switching devices 30b and 30c are not energized, first ground line 10 and second ground line 11 are both connected to vehicle body ground 12.

[0023] Vehicle power supply system 2b also differs from vehicle power supply system 2a in that it includes a switching control device 8b instead of switching control device 8a. Switching control device 8b has a configuration similar to that of switching control device 8a, but differs in that it includes processor 20b including switching control unit 23b instead of processor 20a including switching control unit 23a. Switching control unit 23b has a configuration similar to that of switching control unit 23a, but differs in that when vehicle 1 is in an external charging state, switching control unit 23b electrically disconnects second ground line 11 from first ground line 10 by operating either switching device 30b arranged between first ground line 10 and vehicle body ground 12 or switching device 30c arranged between second ground line 11 and vehicle body ground 12.

[0024] In the vehicle power supply system 2b, for example, when the vehicle 1 is in an external charging state, the switching device 30c is operated to set the connection-off state, thereby electrically disconnecting the second ground line 11 from the vehicle body ground 12 to which the first ground line 10 is connected. This effectively reduces the influence of electromagnetic noise caused by the charging current flowing through the first battery 5 on the AV equipment 4, as in the first embodiment shown in FIG.

[0025] Additionally, in vehicle power supply system 2b, for example, if a charging cable from external charging equipment is connected to charging connector 9, and first grounding line 10 is connected to a grounding line outside the vehicle via charging connector 9 and the charging cable, switching device 30b may be operated to set the connection to an off state when vehicle 1 is in an external charging state. This allows first grounding line 10 to be secured by the grounding line outside the vehicle when first battery 5 is being charged, while second grounding line 11 is maintained in a state where it is grounded to vehicle body ground 12, thereby reducing the effects of electromagnetic noise on AV equipment 4.

[0026] [Third embodiment] Fig. 3 is a diagram showing the configuration of a vehicle power supply system 2c according to a third embodiment of the present invention. In Fig. 3, the same components as those shown in Fig. 1 are designated by the same reference numerals as those shown in Fig. 1, and the description of Fig. 1 above is incorporated herein.

[0027] Vehicle power supply system 2c has a similar configuration to vehicle power supply system 2a, but in addition to first ground line 10 and second ground line 11 being connected via switching device 30a, output line 16 of first battery 5 and output line 17 of second battery 6 are connected via switching device 30d. Switching device 30d is, for example, a normally-on type relay, similar to switching device 30a.

[0028] Vehicle power supply system 2c also differs from vehicle power supply system 2a in that it has switching control device 8c instead of switching control device 8a. Switching control device 8c has a configuration similar to switching control device 8a, but differs in that it has processor 20c including switching control unit 23c instead of processor 20a including switching control unit 23a. Switching control unit 23c differs from switching control unit 23a in that it sets both switching devices 30a and 30d to the connection-on state when vehicle 1 is not in the external charging state, and operates both switching devices 30a and 30d to the connection-off state when vehicle 1 is in the external charging state.

[0029] As a result, in vehicle power supply system 2c, when vehicle 1 is not in an external charging state, output line 16 and first ground line 10 of first battery 5 are connected to output line 17 and second ground line 11 of second battery 6, respectively, and both first battery 5 and second battery 6 can be charged by rotating electric machine 3 during regenerative braking or the like while vehicle 1 is traveling. On the other hand, when vehicle 1 is in an external charging state, vehicle power supply system 2c electrically disconnects output line 16 and first ground line 10 of first battery 5 from output line 17 and second ground line 11 of second battery 6, respectively, so that, similar to the first embodiment shown in FIG. 1 , the effect of electromagnetic noise caused by the charging current flowing through first battery 5 on AV equipment 4 can be effectively reduced.

[0030] [Fourth embodiment] Fig. 4 is a diagram showing the configuration of a vehicle power supply system 2d according to a fourth embodiment of the present invention. In Fig. 4, the same components as those shown in Fig. 1 are designated by the same reference numerals as those shown in Fig. 1, and the explanation given in Fig. 1 above is incorporated herein.

[0031] Vehicle power supply system 2d has a similar configuration to vehicle power supply system 2a, but first battery 5 and second battery 6 are detachably fixed to vehicle 1 via battery sockets 18 and 19, respectively. This allows vehicle power supply system 2d to use, for example, portable mobile batteries as first battery 5 and second battery 6.

[0032] In vehicle power supply system 2d, first ground line 10 and second ground line 11 are connected by switching device 30e, which connects the internal ground lines of battery sockets 18 and 19 to each other. Switching device 30e is, for example, a normally-on type relay, similar to switching device 30a.

[0033] It should be noted that, instead of battery sockets 18 and 19, a single battery socket having two slots into which the first battery 5 and the second battery 6 can be inserted may be used. In this case, the switching device 30e may be built into the battery socket.

[0034] Switching control unit 23a of switching control device 8a sets switching device 30e to the connection-on state when vehicle 1 is not in the external charging state, and operates switching device 30e to the connection-off state when vehicle 1 is in the external charging state. That is, switching control unit 23a turns on and off the electrical connection between the ground line of first battery 5 in battery socket 18 and the ground line of second battery 6 in battery socket 19 using switching device 30e, thereby turning on and off the electrical connection between first ground line 10 and second ground line 11.

[0035] 1, in vehicle power supply system 2d, when vehicle 1 is not in an external charging state, the influence of electromagnetic noise caused by charging current flowing through first battery 5 on AV equipment 4 can be effectively reduced. Also, in vehicle power supply system 2d, switching device 30e connects the internal ground lines of two battery sockets 18, 19, thereby simplifying the configuration of the wire harness routed within vehicle 1 to connect battery sockets 18, 19 with on-vehicle devices. Also, because the respective ground lines are connected in the vicinity of first battery 5 and second battery 6, electromagnetic noise is less likely to occur.

[0036] [Other embodiments] In the above-described embodiments, the shielding structure 14 electromagnetically shields the second load circuit 24b including the AV equipment 4 connected to the second battery 6 from the first load circuit 24a including the rotating electric machine 3 connected to the first battery 5, but the reverse may also be true. That is, the vehicle power supply systems 2a, 2b, 2c, and 2d (hereinafter also collectively referred to as the vehicle power supply system 2) may include a shielding structure that electromagnetically shields one of the first load circuit 24a and the second load circuit 24b from the other load circuit.

[0037] In the vehicle power supply system 2 shown in each of the above-described embodiments, the switching device 30 is a relay controlled by the switching control devices 8a, 8b, and 8c (hereinafter also collectively referred to as the switching control device 8), but is not limited to this. The switching device 30 may be any electrical component, such as a mechanical switch, that can connect and disconnect the first ground line 10 and the second ground line 11.

[0038] For example, the switching device 30 may be a mechanical switch provided in the charging connector 9, which has an electrical contact that breaks when the plug of the charging cable is connected to the charging connector 9 and makes an electrical contact that makes a contact when the plug is removed from the charging connector 9.

[0039] The present invention is not limited to the configurations of the above-described embodiments, and can be implemented in various forms without departing from the spirit of the present invention.

[0040] [Configuration supported by the above embodiment] The above-described embodiment supports the following configurations.

[0041] (Configuration 1) A vehicle power supply system having a first battery that supplies power to a rotating electric machine of a vehicle, a second battery that supplies power to AV equipment mounted on the vehicle, a switching device that electrically disconnects a second ground line of the AV equipment and the second battery from a first ground line of the first battery when the vehicle is in an external charging state in which the first battery is being charged from outside the vehicle, and a shielding structure that electromagnetically shields one of a first load circuit including the rotating electric machine connected to the first battery and a second load circuit including the AV equipment connected to the second battery from the other load circuit. The vehicle power supply system of configuration 1 can effectively reduce the influence on AV equipment of electromagnetic noise caused by a large charging current flowing through the first battery, thereby reducing disturbances to the viewing experience on the AV equipment.

[0042] (Configuration 2) A vehicle power supply system as described in Configuration 1, wherein the switching device disconnects the electrical connection between the first ground line, which is grounded to the ground via the vehicle body, and the second ground line. According to the vehicle power supply system of configuration 2, it is possible to ensure grounding when charging the first battery, while reducing disturbances to the audio-visual experience of AV equipment.

[0043] (Configuration 3) A vehicle power supply system as described in Configuration 1, comprising a battery socket for removably attaching at least one of the first battery and the second battery to the body of the vehicle, and the switching device disconnects the electrical connection between the first ground line and the second ground line by disconnecting the electrical connection between the ground line of the first battery and the ground line of the second battery in the battery socket. According to the vehicle power supply system of configuration 3, the configuration of the wire harness inside the vehicle can be simplified and electromagnetic noise from the first battery can be reduced.

[0044] (Configuration 4) A vehicle power supply system described in any one of configurations 1 to 3, wherein the AV equipment communicates with other equipment installed in the vehicle using a carrier that allows communication even when electrically isolated, at least when the second ground line is electrically disconnected from the first ground line by the switching device. According to the vehicle power supply system of configuration 4, even if the second ground line is disconnected from the first ground line, good communication can be achieved between the AV device and other in-vehicle devices. [Explanation of symbols]

[0045] 1...vehicle, 2, 2a, 2b, 2c, 2d...vehicle power supply system, 3...rotating electric machine, 4...AV equipment, 5...first battery, 6...second battery, 7...ECU, 8, 8a, 8b, 8c...switching control device, 9...charging connector, 10...first ground line, 11...second ground line, 12...vehicle body ground, 13...power supply sensor, 14...shielding structure, 15...photocoupler, 16, 17...output line, 18, 19...battery socket, 20a, 20b, 20c...processor, 21...memory, 22...detection unit, 23a, 23b, 23c...switching control unit, 24a...first load circuit, 24b...second load circuit, 30, 30a, 30b, 30c, 30d, 30e...switching device.

Claims

1. a first battery that supplies power to a rotating electric machine of the vehicle; a second battery for supplying power to AV equipment mounted on the vehicle; a switching device that electrically disconnects a second ground line of the AV equipment and the second battery from a first ground line of the first battery when the vehicle is in an external charging state in which the first battery is charged from outside the vehicle; a shielding structure that electromagnetically shields one of a first load circuit including the rotating electric machine connected to the first battery and a second load circuit including the AV equipment connected to the second battery from the other load circuit; having Vehicle power system.

2. the switching device disconnects the electrical connection between the first ground line, which is grounded to the ground via a body of the vehicle, and the second ground line; 10. The vehicle power supply system of claim 1.

3. a battery socket for detachably mounting at least one of the first battery and the second battery to a body of the vehicle; the switching device electrically disconnects the ground line of the first battery from the ground line of the second battery in the battery socket, thereby electrically disconnecting the first ground line from the second ground line.

10. The vehicle power supply system of claim 1.

4. At least when the second ground line is electrically disconnected from the first ground line by the switching device, the AV device communicates with other devices mounted on the vehicle using a carrier that allows communication even in an electrically isolated state.

4. The vehicle power supply system according to claim 1.

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