Vehicle driving system and vehicle

Abstract

To cause a battery to efficiently function.SOLUTION: A vehicle travel system 10 includes: a travel motor / generator 13 which is connected to a first battery 11 and a second battery 12 via a relay; a power receiving unit 14 which is connected to the first battery 11 and the second battery 12 via a relay and is connected to an external power source 30; and a controller 15. The controller 15 is configured to charge the first battery 11 in the case that a charge state of the first battery 11 is lower than predetermined SOC and to charge the second battery 12 in the case that the charge state of the first battery 11 is SOC or greater when the power receiving unit 14 is connected to the external power source 30.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a vehicle driving system and a vehicle. [Background technology]

[0002] JP 2012-234697 A discloses a battery system. The battery system disclosed in the publication includes a first assembled battery and a second assembled battery for charging and discharging, and a diode. The first assembled battery can be charged and discharged with a current larger than that of the second assembled battery. The second assembled battery has a larger storage capacity than the first assembled battery. The first assembled battery and the second assembled battery are connected in parallel and are connected to a load. The diode is connected in series to the second assembled battery and is connected in parallel to the first assembled battery together with the second assembled battery. The diode allows a discharge current from the second assembled battery to the load, but prevents an excessive current from flowing from the load to the second assembled battery. A charger can be connected to the second assembled battery. The charger can input power from an external power source to the second assembled battery.

[0003] In this battery system, the provision of a diode allows the second assembled battery to only discharge to a load. When the SOC (State Of Charge) of the second assembled battery drops due to discharging, the second assembled battery can be charged using a charger. Since the first assembled battery and the second assembled battery are connected in parallel, if the second assembled battery is charged, a charging current can be passed from the second assembled battery to the first assembled battery, and the first assembled battery can also be charged. With this configuration, it is possible to prevent an excessive current from flowing to the second assembled battery. It is also said that the electrical energy stored in the second assembled battery can be efficiently utilized. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2012-234697 A Summary of the Invention [Problem to be solved by the invention]

[0005] Incidentally, the present inventors have been thinking about how to make the batteries function more efficiently in vehicles equipped with high-output batteries and high-capacity batteries. [Means for solving the problem]

[0006] The vehicle traveling system disclosed herein includes a first battery, a second battery, a traveling motor / generator, a power receiving unit, and a control device. The traveling motor / generator is connected to the first battery and the second battery via a relay, respectively. The power receiving unit is connected to the first battery and the second battery via a relay, respectively, and is connected to an external power source. The first battery is configured to allow charging and discharging at a current value of 5C or more. The second battery is a battery with a higher capacity than the first battery. The control device is configured to charge the first battery when the state of charge of the first battery is lower than a predetermined SOC when the power receiving unit is connected to the external power source, and to charge the second battery when the state of charge of the first battery is equal to or higher than the predetermined SOC.

[0007] With this vehicle drive system, the first battery, which is a high-output battery, is charged first, and as a result, a state in which the drive motor / generator can be driven at high output as required can be quickly established, allowing the batteries to function efficiently.

[0008] The control device determines a current value when charging the first battery from the power receiving unit, Receiving The current value may be configured to be higher than the current value when charging the second battery from the power unit.

[0009] The control device may be configured to input regenerative power to the first battery when the state of charge of the first battery is lower than a predetermined SOC, and to input the power to the second battery when the state of charge of the first battery is equal to or higher than the predetermined SOC, when regenerative power is output from the traction motor / generator.

[0010] The control device may be configured to connect the traction motor / generator to the first battery when the output value required from the traction motor / generator is equal to or greater than a predetermined output value and the state of charge of the first battery is equal to or greater than a predetermined SOC. Furthermore, the control device may be configured to connect the traction motor / generator to the second battery when the output value required from the traction motor / generator is equal to or greater than a predetermined output value and the state of charge of the first battery is lower than the predetermined SOC.

[0011] The control device may be configured to connect the traction motor / generator to the second battery when the output value required from the traction motor / generator is lower than a predetermined output value and the state of charge of the second battery is equal to or higher than a predetermined SOC. Furthermore, the control device may be configured to connect the traction motor / generator to the first battery when the output value required from the traction motor / generator is lower than a predetermined output value and the state of charge of the second battery is lower than the predetermined SOC.

[0012] The control device may be configured to charge the first battery from the second battery when both the first battery and the second battery are disconnected from the traction motor / generator and the state of charge of the first battery is lower than a predetermined SOC.

[0013] The control device may be configured to charge the second battery from the first battery when both the first battery and the second battery are disconnected from the traction motor / generator and the state of charge of the first battery is higher than a predetermined SOC.

[0014] The first battery may be lighter and smaller than the second battery. Furthermore, the vehicle driving system disclosed herein may be appropriately installed in a vehicle. [Brief description of the drawings]

[0015] [Figure 1] FIG. 1 is a schematic diagram of a vehicle driving system 10 disclosed herein. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] An embodiment of the vehicle driving system disclosed herein will be described below. The embodiment described herein is, of course, not intended to limit the present invention. The present invention is not limited to the embodiment described herein unless otherwise specified. Each drawing is drawn typically and does not necessarily reflect the actual product. In addition, the same reference numerals are appropriately assigned to members and parts that perform the same function, and duplicated descriptions are omitted.

[0017] Vehicle Driving System 10 1 is a schematic diagram of a vehicle traveling system 10 disclosed herein. The vehicle traveling system 10 includes a first battery 11, a second battery 12, a traveling motor / generator 13, a power receiving unit 14, and a control device 15. The vehicle traveling system 10 can be connected to an external power source 30 outside the system and charged. Vehicles to which the vehicle traveling system 10 is applied include not only electric vehicles, but also small vehicles such as electric scooters and electric motorcycles.

[0018] <First battery 11, second battery 12> The first battery 11 is configured to be allowed to be charged and discharged at a current value of 5C or more, which is higher than the current value allowed for the second battery 12. The second battery 12 is a battery with a higher capacity than the first battery 11. In other words, the first battery 11 is capable of being charged and discharged at a high current value, and is configured as a so-called high-output battery. On the other hand, the second battery 12 is configured as a so-called high-capacity battery. The first battery 11 is appropriately referred to as a "high-output battery". The second battery 12 is appropriately referred to as a "high-capacity battery".

[0019] More specifically, both the first battery 11 and the second battery 12 have the required output performance as a power source for driving the driving motor / generator 13 for driving the vehicle. However, the first battery 11 is preferably designed to be able to be charged and discharged at a particularly high current value compared to the second battery 12. The second battery 12 is preferably designed to have a particularly high capacity compared to the first battery 12. That is, the first battery 11 has a structure that is less likely to deteriorate when charged and discharged at a high current value in a relative evaluation to the second battery 12, in addition to functioning as a power source for driving the vehicle. In this embodiment, the first battery 11 has excellent performance in terms of high output characteristics. On the other hand, the second battery 12 is superior in terms of high capacity in a relative evaluation to the first battery 11, in addition to functioning as a power source for driving the vehicle.

[0020] The second battery 12 may have high output characteristics equivalent to those of the first battery 11. The second battery 12 may have a higher capacity than the first battery 11, but may have output characteristics inferior to those of the first battery 11. The first battery 11 may be used as an assembled battery as appropriate. The second battery 12 may be a single cell and may be used as an assembled battery as appropriate. For a large vehicle that requires a large load when traveling, the first battery 11 and the second battery 12 are preferably used as an assembled battery. For a small vehicle that requires a small load when traveling, the first battery 11 may be a single cell. Similarly, the second battery 12 may also be a single cell.

[0021] The first battery 11 may be, for example, a battery used as a driving power source for a hybrid vehicle. A hybrid vehicle is equipped with an internal combustion engine, and power can be generated by the power obtained by the internal combustion engine. For this reason, high capacity is not so important for a battery used as a driving power source for a hybrid vehicle. On the other hand, in order to improve the fuel efficiency of a hybrid vehicle, it is desirable to recover as much regenerative energy as possible generated by the driving motor / generator 13 during braking. The regenerative energy is generated according to the kinetic energy during braking. For this reason, a large amount of energy can be instantaneously generated as regenerative energy. From the viewpoint of recovering as much of the regenerative energy as possible, it is preferable that a battery used as a driving power source for a hybrid vehicle has a structure that is not easily deteriorated by charging and discharging at a high current value.

[0022] Thus, the battery used as the driving power source of the hybrid vehicle is pursued to efficiently recover the regenerative energy converted into electric power, rather than to increase the capacity. As a typical example of the lithium-ion secondary battery used as the driving power source of the hybrid vehicle, a so-called NMC ternary lithium-containing transition metal composite oxide containing nickel manganese cobalt is used as the positive electrode active material, graphite is used as the negative electrode active material, and ethylene carbonate or ethyl methyl carbonate is used as the electrolyte. Furthermore, the lithium-ion secondary battery used as the driving power source of the hybrid vehicle is, for example, devised in terms of the structure of the active material layer, the viscosity, composition, and additives of the electrolyte. For example, in a prismatic battery mounted on a hybrid vehicle, a charge / discharge current of about 30C can be realized while suppressing deterioration of the secondary battery. The battery applied to the first battery 11 is not limited to the one exemplified here. It is expected that further research will further evolve the driving power source of the hybrid vehicle in the future, and charging at an even higher current value will become possible. The first battery 11 may be a battery having a structure that is resistant to deterioration, particularly when charged and discharged at a high current value.

[0023] The second battery 12 may be, for example, a high-capacity battery for a BEV (Battery Electric Vehicle) that runs by driving a drive motor with a battery power source. Such a high-capacity battery may use lithium cobalt oxide as the positive electrode active material, graphite as the negative electrode active material, or a gel of an electrolyte solution impregnated in a polymer made of polyethylene oxide or polyvinylidene fluoride. With such a configuration, an energy density of about 200 to 300 Wh / g may be realized. In addition, charging and discharging at a current value of about 1C to 3C may be permitted. In such a secondary battery, charging and discharging at a relatively large current value, such as 5C or more than 10A, tends to be unacceptable because it causes early deterioration. In addition, the charging speed may be controlled to be slowed down when the remaining capacity exceeds 80%. In this way, the second battery 12 may have a higher capacity than the first battery 11 in order to increase the driving range of the vehicle. On the other hand, the second battery 12 may be more susceptible to degradation when charged or discharged at a high current than the first battery 11. For this reason, the second battery 12 may be used together with a mechanism for limiting the current value during charging or discharging.

[0024] In this embodiment, the first battery 11 and the second battery 12 are electrically connected via a relay r1. The first battery 11 is provided with a sensor s1 that detects a voltage value and a current value. The second battery 12 is provided with a sensor s2 that detects a voltage value and a current value. The sensors s1 and s2 are each connected to the control device 15, and the detection signals of the sensors s1 and s2 are each sent to the control device 15. The sensor s1 may further have a function of detecting the temperature of the first battery 11. The sensor s2 may further have a function of detecting the temperature of the second battery 12.

[0025] <Traction motor / generator 13> The traction motor / generator 13 is a device that has the functions of a traction motor and a generator. The traction motor / generator 13 is configured to receive electric power to generate kinetic energy used for the vehicle's travel, and to convert the kinetic energy generated when the vehicle is braked into electrical energy. The traction motor / generator 13 is a device that converts kinetic energy into electrical energy when the vehicle is decelerated or stopped.

[0026] In this embodiment, the traveling motor / generator 13 and the first battery 11 are electrically connected via a relay r2. The relay r2 is incorporated in the control unit c1. The traveling motor / generator 13 and the second battery 12 are electrically connected via a relay r3. The relay r3 is incorporated in the control unit c2. Various types of such traveling motor / generator 13 have been proposed as motors for electric vehicles. It is expected that the traveling motor / generator 13 will further evolve and become capable of outputting with even higher efficiency as research progresses in the future. Therefore, the traveling motor / generator 13 is not limited to those currently known. In this embodiment, the traveling motor / generator 13 is provided with a sensor s3 that detects the generation of regenerative power. The sensor s3 is preferably configured to detect the magnitude of the regenerative power.

[0027] <Power receiving unit 14> The power receiving unit 14 is a unit that receives power from an external power source 30. The external power source 30 may be a home power source or a power source installed at a charging spot in town. The power receiving unit 14 is a device configured to be electrically connected to the external power source 30 by wire or wirelessly (non-contact). In this embodiment, the power receiving unit 14 is provided with a sensor s4 that detects the connection with the external power source 30. The sensor s4 may be configured to detect the wired connection or wireless electrical connection between the power receiving unit 14 and the external power source 30. The detection signal of the sensor s4 is sent to the control device 15. The power receiving unit 14 and the first battery 11 are electrically connected via a relay r4. The power receiving unit 14 and the second battery 12 are electrically connected via a relay r5. The specific configuration of the sensor s4 is not specifically disclosed here, but a mechanical detection means or an electrical detection means may be applied as appropriate. Such a detection means may be appropriately adopted by a person skilled in the art.

[0028] <Relays r1 to r5> The relays r1 to r5 can be realized as semiconductor relays controlled by the control device 15. In this embodiment, the relays r1 to r5 are incorporated in the control units c1 to c5, respectively. The relays r1 to r5 are switched ON / OFF by the control device 15, respectively. The control units c1 to c5 also include an inverter, a DC-DC converter, and the like, as appropriate. For example, the relay r1 connects the first battery 11 and the second battery 12. At this time, the control unit c1 controls the voltage as appropriate using the DC-DC converter incorporated in the control unit c1, as well as the ON / OFF of the relay r1. Then, the control unit c1 controls the charging between the first battery 11 and the second battery 12.

[0029] Furthermore, relay r2 connects the first battery 11 and the drive motor / generator 13. Relay r3 connects the second battery 12 and the drive motor / generator 13. The input and output of secondary batteries such as the first battery 11 and the second battery 12 is DC. In contrast, the input and output of the drive motor / generator 13 is AC. When a voltage is applied from the first battery 11 and the second battery 12 to the drive motor / generator 13, the control units c2 and c3 convert the DC to AC. This conversion is performed by an inverter incorporated in the control units c2 and c3. Furthermore, when the output voltage of the first battery 11 and the second battery 12 is lower than the control voltage of the drive motor / generator 13, the DC-DC converter incorporated in the control units c2 and c3 boosts the voltage.

[0030] The relay r4 connects the first battery 11 and the power receiving unit 14. The relay r5 connects the second battery 12 and the power receiving unit 14. The power receiving unit 14 is connected to the external power source 30. The voltage of the relay r4 is appropriately controlled according to the input / output characteristics of the first battery 11. The voltage of the relay r5 is appropriately controlled according to the input / output characteristics of the second battery 12. The control of the charging current from the external power source 30 to the first battery 11 may be performed by the control unit c4 incorporating the relay r4 or the power receiving unit 14. The control of the charging current from the external power source 30 to the second battery 12 may be performed by the control unit c5 incorporating the relay r5 or the power receiving unit 14. To realize such control, the control units c4, c5 and the power receiving unit 14 may be appropriately equipped with an inverter, a DC-DC converter, etc.

[0031] In FIG. 1, charging from the power receiving unit 14 to the first battery 11 is designated as "Charge I." Charging from the power receiving unit 14 to the second battery 12 is designated as "Charge II." Charging from the travel motor / generator 13 to the first battery 11 is designated as "Charge III." Charging from the travel motor / generator 13 to the second battery 12 is designated as "Charge IV." Charging from the second battery 12 to the first battery 11 is designated as "Charge V." Charging from the first battery 11 to the second battery 12 is designated as "Charge VI." Furthermore, power supply from the first battery 11 to the travel motor / generator 13 is designated as "Mode I." Power supply from the second battery 12 to the travel motor / generator 13 is designated as "Mode II."

[0032] <Control device 15> The control device 15 is configured to charge the first battery 11 when the power receiving unit 14 is connected to the external power source 30 if the state of charge of the first battery 11 is lower than a predetermined SOC, and to charge the second battery 12 when the state of charge of the first battery 11 is equal to or higher than the predetermined SOC. With this configuration, when the power receiving unit 14 is connected to the external power source 30, charging from the power receiving unit 14 to the first battery 11, "Charge I," is given priority over charging from the power receiving unit 14 to the second battery 12, "Charge II."

[0033] In this embodiment, whether or not the power receiving unit 14 is connected to the external power supply 30 is determined based on a detection signal from a sensor s4 provided in the power receiving unit 14. Whether or not the state of charge of the first battery 11 is lower than a predetermined SOC is determined based on a sensor s1 provided in the first battery 11. For example, the sensor s1 detects information such as the voltage value, current value, and temperature of the first battery 11. The control device 15 may be configured to obtain the state of charge (SOC) of the first battery 11 based on the detection data such as the voltage value, current value, and temperature of the first battery 11 acquired from the sensor s1. Various methods for estimating the SOC of the first battery 11 have been proposed for secondary batteries, and an appropriate method for the first battery 11 may be appropriately adopted. When the control device 15 determines that the power receiving unit 14 is connected to the external power source 30 based on the detection signal of the sensor s4, and further when the charging state of the first battery 11 is lower than a predetermined SOC based on the sensor s1, the control device 15 controls the power receiving unit 14 to charge the first battery 11.

[0034] In this case, in the embodiment shown in Fig. 1, the control device 15 may turn on relay r4 and turn off relay r5, relay r1, and relay r2. This connects the power receiving unit 14 connected to the external power source 30 with the first battery 11, and charges the first battery 11 through the power receiving unit 14. On the other hand, when the power receiving unit 14 is connected to the external power source 30, if the state of charge of the first battery 11 is equal to or higher than a predetermined SOC, the second battery 12, which is a high-capacity battery, is charged. In this case, in the embodiment shown in Fig. 1, the control device 15 may turn on relay r5 and turn off relay r4, relay r1, and relay r3.

[0035] According to this control, when the power receiving unit 14 is connected to the external power source 30 and the state of charge of the first battery 11 is lower than a predetermined SOC, the first battery 11, which is a high-output battery, is charged preferentially. This ensures that the high-output battery can be used preferentially after charging with the external power source 30. This allows the high-output battery to supply power to the traveling motor / generator 13, quickly ensuring a state in which the traveling motor / generator 13 can be driven at high output as required. This allows the first battery 11 and the second battery 12 to function efficiently.

[0036] In the above control, the predetermined SOC for the state of charge of the first battery 11 may be SOC100%, which is the upper limit SOC of the usage range set for the first battery 11. Also, in order to suppress deterioration of the first battery 11 after charging and to accept regenerative energy, a margin may be left in the charge amount. From this point of view, in the above control, the predetermined SOC for the state of charge of the first battery 11 may be about SOC80%. In this way, in the above control, the predetermined SOC for the state of charge of the first battery 11 may be appropriately set to any SOC within the range of about SOC100% to 70%, which is the upper limit SOC of the usage range set for the first battery 11. Similarly, the state of charge (SOC) of the second battery 12 may be estimated by a predetermined process of the control device 15 based on information detected by the sensor s2.

[0037] The control device 15 may be configured so that the current value when charging the first battery 11 from the power receiving unit 14 is higher than the current value when charging the second battery 12 from the power receiving unit 14. The control device 15 may be configured, for example, to control the control unit c4 so that the voltage applied to the first battery 11 is higher when charging the first battery 11 from the power receiving unit 14. This increases the current value when charging the first battery 11. The first battery 11 is then charged quickly. For this reason, for example, even if both the first battery 11 and the second battery 12 are out of charge, the first battery 11 is charged quickly, so that the vehicle travel system 10 can be quickly restored to a charge state where it can be used if the vehicle is travelling a short distance.

[0038] The control device 15 is configured to charge the first battery 11 preferentially when regenerative power is output from the travel motor / generator 13. Specifically, the control device 15 may be configured to input regenerative power to the first battery 11 when the state of charge of the first battery 11 is lower than a predetermined SOC when regenerative power is output from the travel motor / generator 13, and to input the power to the second battery 12 when the state of charge of the first battery 11 is equal to or higher than the predetermined SOC. With this configuration, when regenerative power is generated by the travel motor / generator 13, charging "Charge III" from the travel motor / generator 13 to the first battery 11 is given priority over charging "Charge IV" from the travel motor / generator 13 to the second battery 12.

[0039] The regenerative electric power generated by the traction motor / generator 13 is generated when braking the vehicle's kinetic energy, and a large amount of electric power can be generated instantaneously. In contrast, the first battery 11 can tolerate a higher charging current than the second battery 12. Therefore, when regenerative electric power is output from the traction motor / generator 13, the first battery 11 is configured to be charged preferentially, so that more of the regenerative electric power generated by the traction motor / generator 13 can be recovered. As a result, the recovered electric power is used to drive the vehicle. This makes it possible to extend the vehicle's cruising range.

[0040] Here, when regenerative power is input from the travel motor / generator 13 to the first battery 11, in the embodiment shown in Fig. 1, the control device 15 may turn on relay r2 and turn off relays r1, r3 and r4. This connects the travel motor / generator 13 and the first battery 11. Then, the regenerative power generated by the travel motor / generator 13 is charged to the first battery 11. At this time, the voltage and current values ​​may be appropriately controlled by the control unit c2.

[0041] On the other hand, when regenerative power is input from the travel motor / generator 13 to the second battery 12, in the embodiment shown in Fig. 1, the control device 15 may turn relay r3 ON and relays r1, r2 and r5 OFF. This connects the travel motor / generator 13 and the second battery 12. The regenerative power generated by the travel motor / generator 13 is then charged into the second battery 12. At this time, the voltage and current values ​​may be appropriately controlled by the control unit c3.

[0042] For example, the upper limit of the allowable current value of the second battery 12 is lower than that of the first battery 11. From this viewpoint, it is preferable to control the current value. currentA constant current diode d3 may be incorporated in the path. The constant current diode d3 is preferably configured to limit the current flowing from the traction motor / generator 13 to the second battery 12 to a certain level or less.

[0043] The control device 15 may be configured to connect the traction motor / generator 13 to the first battery 11 when the output value required by the traction motor / generator 13 is equal to or greater than a predetermined output value and the state of charge of the first battery 11 is equal to or greater than a predetermined SOC. Furthermore, the control device 15 may be configured to connect the traction motor / generator 13 to the second battery 12 when the output value required by the traction motor / generator 13 is equal to or greater than a predetermined output value and the state of charge of the first battery 11 is lower than the predetermined SOC.

[0044] According to this configuration, when the output value required by the traveling motor / generator 13 is high, i.e., when the load is high, the first battery 11, which is a high-output battery, is preferentially supplied with power to the traveling motor / generator 13. In other words, when the output value required by the traveling motor / generator 13 is high, the power supply "Mode I" from the first battery 11 to the traveling motor / generator 13 is prioritized. This control can be applied, for example, when the vehicle accelerates suddenly or climbs a slope. The first battery 11 has high output resistance and can output a high current value in response to the request of the traveling motor / generator 13. On the other hand, the first battery 11 does not have a high capacity compared to the second battery 12. In this embodiment, the traveling motor / generator 13 is configured to be connected to the second battery 12 when the output value required by the traveling motor / generator 13 is equal to or higher than a predetermined output value and the state of charge of the first battery 11 is lower than a predetermined SOC.

[0045] Therefore, even if the required level of output value of the traction motor / generator 13 cannot be achieved, the vehicle can continue traveling without stopping the power supply to the traction motor / generator 13. Also, the SOC of the first battery 11 can be prevented from becoming lower than a predetermined SOC. This suppresses deterioration of the first battery 11. Also, as described above, the regenerative power from the traction motor / generator 13 is configured to be preferentially supplied to the first battery 11, which allows the first battery 11 to quickly recover from its SOC and improves its usage rate.

[0046] The control device 15 may connect the traction motor / generator 13 to the second battery 12 when the output value required by the traction motor / generator 13 is lower than a predetermined output value and the state of charge of the second battery 12 is equal to or higher than a predetermined SOC. Furthermore, the control device 15 may be configured to connect the traction motor / generator 13 to the first battery 11 when the output value required by the traction motor / generator 13 is lower than a predetermined output value and the state of charge of the second battery 12 is lower than a predetermined SOC. In other words, when the output value required by the traction motor / generator 13 is low, priority is given to "Mode II" power supply from the second battery 12 to the traction motor / generator 13.

[0047] According to this configuration, when the output value required by the traveling motor / generator 13 is low, that is, when the load is low, the second battery 12, which is a high-capacity battery, is preferentially supplied with power to the traveling motor / generator 13. This control can be applied, for example, when traveling at a low and constant speed. The first battery 11 has high output resistance and can output a high current value in response to the request of the traveling motor / generator 13. On the other hand, the first battery 11 does not have a high capacity compared to the second battery 12. In this embodiment, when the output value required by the traveling motor / generator 13 is low, the first battery 11 does not supply power to the traveling motor / generator 13. Therefore, the power stored in the first battery 11 can be preserved. As a result, the power stored in the first battery 11 is not consumed unnecessarily. Therefore, when the output value required by the traveling motor / generator 13 is high, it is easier to meet the demand with the power supply from the first battery 11.

[0048] That is, in this embodiment, the vehicle traveling system 10 includes a first battery 11 which is a high-output battery and a second battery 12 which is a high-capacity battery. When charging / discharging at a high current value is not required, the first battery 11 is preserved. When charging / discharging at a high current value is required, the first battery 11 is controlled so as to be used preferentially. Furthermore, the regenerative power generated by the traveling motor / generator 13 is configured to be charged preferentially to the first battery 11. This makes it possible to appropriately output high power in response to the demands of the traveling motor / generator 13.

[0049] In this embodiment, the control device 15 is configured to charge the first battery 11 from the second battery 12 (i.e., Charge V) when both the first battery 11 and the second battery 12 are disconnected from the travel motor / generator 13 and the state of charge of the first battery 11 is lower than a predetermined SOC. In this case, in the embodiment shown in FIG. 1, the control device 15 may turn on relay r1 and turn off relays r2 to r5. This connects the first battery 11 and the second battery 12. Then, the control unit c1 may adjust the voltage between the first battery 11 and the second battery 12 so that a current flows from the first battery 11 to the second battery 12.

[0050] According to this configuration, charging of the first battery 11 from the second battery 12 is appropriately performed. Therefore, when both the first battery 11 and the second battery 12 are disconnected from the driving motor / generator 13, power is supplied from the second battery 12 to the first battery 11, and the state of charge of the first battery 11 is restored to a predetermined SOC. Therefore, when the output value required by the driving motor / generator 13 is high, the probability that power can be supplied from the first battery 11, which is a high-output battery, to the driving motor / generator 13 increases. Therefore, the driving motor / generator 13 produces the required output at a higher rate, and the driving performance of the vehicle is improved. The control of power supply from the second battery 12 to the first battery 11 may be configured to stop when the first battery 11 reaches a predetermined SOC, for example. This prevents excessive power from being supplied from the second battery 12 to the first battery 11.

[0051] Furthermore, in this embodiment, the control device 15 is configured to charge the second battery 12 from the first battery 11 (i.e., Charge VI) when both the first battery 11 and the second battery 12 are disconnected from the travel motor / generator 13 and the state of charge of the first battery 11 is higher than a predetermined SOC. In this case, in the embodiment shown in FIG. 1, the control device 15 may turn on relay r1 and turn off relays r2 to r5. This connects the first battery 11 and the second battery 12. Then, the control unit c1 may adjust the voltage between the first battery 11 and the second battery 12 so that a current flows from the second battery 12 to the first battery 11.

[0052] For example, the regenerative power generated by the traveling motor / generator 13 may be charged to the first battery 11, causing the state of charge of the first battery 11 to be higher than a predetermined SOC. In this embodiment, in such a case, the first battery 11 charges the second battery 12 until the first battery 11 reaches the predetermined SOC. As a result, the state of charge of the first battery 11 becomes low. Furthermore, when regenerative power is generated by the traveling motor / generator 13, the regenerative power is charged to the first battery 11, improving the efficiency of recovery of the regenerative power. Note that the control of the supply of power from the first battery 11 to the second battery 12 may be configured to stop, for example, when the first battery 11 reaches the predetermined SOC. This prevents excessive power from being supplied from the first battery 11 to the second battery 12, and maintains the first battery 11 in a high state of charge.

[0053] The first battery 11 is preferably lighter and smaller than the second battery 12. The first battery 11 is preferably constructed to be less expensive than the second battery 12. In this embodiment, as described above, the first battery 11 is used more frequently. The first battery 11 is repeatedly charged and discharged at a high current value. For this reason, although the first battery 11 is constructed as a high-output battery that is less likely to deteriorate when charged and discharged at a high current value, performance degradation may gradually progress.

[0054] On the other hand, this vehicle traveling system 10 is equipped with the first battery 11, which is a high-output battery, and high-rate (high current value) use of the second battery 12, which is a high-capacity battery, is suppressed. As a result, the second battery 12 can have a significantly longer life than the first battery 11. The first battery 11 is replaced more frequently than the second battery 12, but is constructed to be less expensive than the second battery 12. As a result, the long-term maintenance costs of the vehicle traveling system 10 as a whole can be kept low. And, in this vehicle traveling system 10, the first battery 11 can be treated as a consumable part with a shorter span than the second battery 12. The first battery 11 is lighter and smaller than the second battery 12, making it easier to handle and reducing the workload when replacing it.

[0055] The vehicle traveling system 10 also includes a first battery 11 and a second battery 12. The first battery 11 and the second battery 12 are connected to a traveling motor / generator 13 and a power receiving unit 14, respectively. Therefore, even if one of them breaks down, the vehicle will not immediately become unable to travel. In particular, even if the first battery 11 breaks down, as long as the second battery 12, which is a high-capacity battery, does not break down, power can still be supplied to the traveling motor / generator 13, and long-distance traveling can also be ensured. Therefore, according to the vehicle traveling system 10, a system that is unlikely to become unable to travel due to a battery as a whole can be provided.

[0056] The vehicle travel system 10 disclosed herein can be suitably applied as a travel system for so-called electric vehicles. The vehicle travel system 10 disclosed herein can be suitably applied not only to electric vehicles, but also to small vehicles such as electric scooters, electric motorcycles, electric kickboards, and electric unicycles. It can also be applied to large vehicles such as electric buses. The specific configuration of a vehicle to which the vehicle travel system 10 can be applied is preferably such that the travel motor / generator 13 is mechanically connected to the drive mechanism of the vehicle. The specific configuration of such a vehicle is not particularly limited, and various configurations have been proposed as the configuration of an electric vehicle.

[0057] The vehicle driving system disclosed herein has been described above in various ways. Unless otherwise specified, the embodiments of the vehicle driving system described herein do not limit the present invention. Furthermore, the vehicle driving system disclosed herein can be modified in various ways, and each component and each process described herein can be omitted or combined as appropriate, unless a particular problem occurs. [Explanation of symbols]

[0058] 10 Vehicle Driving System 11 First battery (high power battery) 12 2nd battery (high capacity battery) 13 Travel motor / generator 14 Power receiving unit 15 Control device 30 External power supply c1~c5 control unit r1~r5 Relay s1~s4 Sensors

Claims

1. A first battery; A second battery; a motor / generator for driving connected to the first battery and the second battery via a relay, Control device and Equipped with The first battery is configured to be allowed to be charged and discharged at a current value of 5 C or more, the second battery is a battery having a higher capacity than the first battery, a constant current diode is connected in series to a current path between the driving motor / generator and the second battery so as to limit the current flowing from the driving motor / generator to the second battery to a certain level or less; The control device includes: When regenerative power is output from the traction motor / generator, if the state of charge of the first battery is lower than a predetermined SOC, the regenerative power is input to the first battery, and if the state of charge of the first battery is equal to or higher than the predetermined SOC, the regenerative power is input to the second battery; and the first battery and the second battery are both disconnected from the driving motor / generator, and when the state of charge of the first battery is lower than a predetermined SOC, the first battery is charged from the second battery. Vehicle driving system.

2. The control device includes:

2. A vehicle driving system as described in claim 1, wherein the first battery and the second battery are both disconnected from the driving motor / generator, and the second battery is charged from the first battery when the state of charge of the first battery is higher than a predetermined SOC.

3. A first battery; A second battery; a motor / generator for driving connected to the first battery and the second battery via a relay, Control device and Equipped with The first battery is configured to be allowed to be charged and discharged at a current value of 5 C or more, the second battery is a battery having a higher capacity than the first battery, a constant current diode is connected in series to a current path between the driving motor / generator and the second battery so as to limit the current flowing from the driving motor / generator to the second battery to a certain level or less; The control device includes: When regenerative power is output from the traction motor / generator, if the state of charge of the first battery is lower than a predetermined SOC, the regenerative power is input to the first battery, and if the state of charge of the first battery is equal to or higher than the predetermined SOC, the regenerative power is input to the second battery; and A vehicle driving system configured such that both the first battery and the second battery are disconnected from the driving motor / generator, and when the state of charge of the first battery is higher than a predetermined SOC, charging of the second battery is performed from the first battery.

4. The vehicle driving system according to claim 1 , wherein the first battery is lighter and smaller than the second battery.

5. A first battery; A second battery; a motor / generator for driving connected to the first battery and the second battery via a relay, Control device and Equipped with The first battery is configured to be allowed to be charged and discharged at a current value of 5 C or more, the second battery is a battery having a higher capacity than the first battery, a constant current diode is connected in series to a current path between the driving motor / generator and the second battery so as to limit the current flowing from the driving motor / generator to the second battery to a certain level or less; the first battery is lighter and smaller than the second battery; The control device includes: When regenerative power is output from the traction motor / generator, the regenerative power is input to the first battery when the state of charge of the first battery is lower than a predetermined SOC, and the regenerative power is input to the second battery when the state of charge of the first battery is equal to or higher than the predetermined SOC. Vehicle driving system.

6. a first relay connecting the first battery and the traction motor / generator; a second relay connecting the second battery and the traction motor / generator; Further equipped with The control device includes: When regenerative power is output from the traction motor / generator, if the state of charge of the first battery is lower than a predetermined SOC, the first relay is turned on to input the power to the first battery, and if the state of charge of the first battery is equal to or higher than a predetermined SOC, the second relay is turned on to input the power to the second battery. A vehicle driving system according to any one of claims 1 to 5.

7. a power receiving unit connected to the first battery and the second battery via a relay, and connected to an external power source; When the power receiving unit is connected to an external power source, the power receiving unit is configured to charge the first battery when the state of charge of the first battery is lower than a predetermined SOC, and to charge the second battery when the state of charge of the first battery is equal to or higher than the predetermined SOC. A vehicle driving system according to any one of claims 1 to 6.

8. The control device includes:

8. The vehicle driving system according to claim 7, wherein a current value when charging the first battery from the power receiving unit is higher than a current value when charging the second battery from the power receiving unit.

9. The control device includes: When an output value required from the driving motor / generator is equal to or greater than a predetermined output value and a state of charge of the first battery is equal to or greater than a predetermined SOC, the driving motor / generator is connected to the first battery, and The vehicle is configured such that, when an output value required from the driving motor / generator is equal to or greater than a predetermined output value and a state of charge of the first battery is lower than a predetermined SOC, the driving motor / generator is connected to the second battery. A vehicle driving system according to any one of claims 1 to 8.

10. The control device includes: When an output value required from the driving motor / generator is lower than a predetermined output value and the state of charge of the second battery is equal to or higher than a predetermined SOC, the driving motor / generator is connected to the second battery, and the driving motor / generator is configured to be connected to the first battery when an output value required from the driving motor / generator is lower than a predetermined output value and a state of charge of the second battery is lower than a predetermined SOC; A vehicle driving system according to any one of claims 1 to 9.

11. A vehicle equipped with the vehicle driving system according to any one of claims 1 to 10.

Images