Vehicle charging and discharging systems

Abstract

A charging / discharging system (1) comprises: a rotating electric machine (2) capable of outputting travel drive force; a drive circuit unit (5) that supplies the power of a main battery (3) to drive the rotating electric machine (2) and charges the main battery (3) by the regeneration of the rotating electric machine (2); and a control unit (10) that controls the drive circuit unit (5). The charging / discharging system (1) is configured so as not to charge a backup battery (200) by the regeneration of the rotating electric machine (2), said backup battery (200) being connectable to the drive circuit unit (5).

Description

[Technical Field]

[0001] The present invention relates to a vehicle charge / discharge system mounted on a vehicle. [Background technology]

[0002] In recent years, electric vehicles, plug-in hybrid vehicles, and other vehicles are equipped with batteries that supply power to drive motor generators and also recover and charge regenerated power.As batteries deteriorate, their charge capacity decreases and the driving distance per charge becomes shorter.However, replacing batteries with new ones is often expensive, so there is a demand for preventing deterioration as much as possible and extending their lifespan.

[0003] For this reason, a proposal has been made to equip a sub-battery separate from the main battery, with a higher state of charge (SOC) than the main battery and configured to be usable under heavy loads (see Patent Document 1). This allows for degradation of the sub-battery, and by frequently replacing the sub-battery, which is cheaper than the main battery, it is possible to extend the life of the main battery and reduce costs overall. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-118109 Summary of the Invention [Problem to be solved by the invention]

[0005] However, when using a vehicle, there is a risk that the battery may run out of charge due to various reasons, such as when the vehicle is stuck in traffic for a long time or when the vehicle is stranded due to bad weather (heavy snow), making it impossible to charge the battery. To prepare for such situations, it is possible to install a spare battery that can be used to move the vehicle to a location where it can be charged or to secure a power source that can serve as a heat source for life support. However, in a configuration that actively tolerates deterioration of the sub-battery, as in Patent Document 1, when the main battery runs out of power, the sub-battery may have deteriorated so much that it may no longer be able to function as a spare battery.

[0006] Therefore, an object of the present invention is to provide a vehicle charging / discharging system that can reduce the deterioration of a spare battery and function as a spare battery when the main battery runs out of power. [Means for solving the problem]

[0007] One aspect of the present invention is a rotating electric machine capable of outputting driving force for running; a drive circuit unit that supplies power from a main battery to drive the rotating electric machine and charges the main battery through regeneration by the rotating electric machine; a control unit that controls the drive circuit unit; a switching unit that is interposed between the drive circuit unit and a spare battery mounting unit connectable to the drive circuit unit and that can be manually switched between a state in which power is supplied from the spare battery to the drive circuit unit and a state in which power is cut off, before Prediction The auxiliary battery is not charged by regeneration of the rotating electric machine. R, the control unit disables switching by the switching unit until the remaining charge of the main battery becomes equal to or less than a predetermined remaining charge, and enables switching by the switching unit when the remaining charge becomes equal to or less than the predetermined remaining charge. This is a charging and discharging system for a vehicle.

[0008] This reduces the deterioration of the spare battery, and allows the spare battery to function as a spare battery when the main battery runs out of power. [Brief explanation of the drawings]

[0009] [Figure 1]1 is a block diagram showing a vehicle charging / discharging system according to an embodiment of the present invention; DETAILED DESCRIPTION OF THE INVENTION

[0010] A vehicle charging / discharging system according to this embodiment will now be described with reference to Fig. 1. Fig. 1 is a block diagram showing a vehicle charging / discharging system according to this embodiment.

[0011] A vehicle charging / discharging system (hereinafter simply referred to as "charging / discharging system") 1 according to this embodiment is mounted on a vehicle 100, such as an electric vehicle. The vehicle 100 is equipped with wheels (not shown) driven by a motor / generator (hereinafter simply referred to as "motor") 2, a steering mechanism for steering the wheels, and the like. The vehicle 100 is also equipped with auxiliary equipment 20, such as an air conditioner, headlamps, and a cooling system for cooling various parts of the charging / discharging system 1, which supplies refrigerant.

[0012] Vehicle 100 is also equipped with a rapid charging port 101 that can be connected to a rapid charger 301, and a normal charging port 102 that can be connected to a normal charger 302. Rapid charger 301 is a charger that can supply a larger current than normal charger 302 at a voltage of, for example, 200V, while normal charger 302 is a charger that can supply a current from a household commercial power source with a voltage of, for example, 100V to 200V. Rapid charger 301 may use a higher voltage than normal charger 302.

[0013] The charging / discharging system 1 mounted on the vehicle 100 mainly performs the driving function and includes a motor 2, which is a rotating electric machine capable of outputting driving force for driving, a main battery 3 capable of storing power to be supplied to the motor 2, a drive circuit unit 5 having an inverter 5A and a regenerative converter 5B, and a control unit (ECU) 10. The charging / discharging system 1 also includes a charging circuit unit 7 having a rapid charging circuit unit 7A and a normal charging circuit unit 7B as a unit for externally charging the main battery 3. The rapid charging circuit unit 7A is connected to the rapid charging port 101, and the normal charging circuit unit 7B is connected to the normal charging port 102. The main battery 3 is formed, for example, from a lithium-ion battery capable of outputting current at a voltage of 400V.

[0014] That is, when a rapid charger 301 is connected to the rapid charge port 101, the main battery 3 is rapid-charged via the rapid charge circuit unit 7A with a current greater than that of the normal charge circuit unit 7B described below, or when a normal charger 302 is connected to the normal charge port 102, the main battery 3 is normally-charged via the normal charge circuit unit 7B with a current smaller than that of the rapid charge.

[0015] Furthermore, when the vehicle 100 is traveling and accelerating, power is supplied from the main battery 3 to the motor 2 by PWM control of the inverter 5A or the like, thereby driving the motor 2 to power, and the wheels (not shown) are driven by this driving force, causing the vehicle to travel. When the vehicle 100 is traveling and decelerating, the wheels (not shown) are rotated by the inertial force of the vehicle 100, causing the motor 2 to rotate, and the regenerative converter 5B causes the motor 2 to regenerate, recovering the regenerated power in the main battery 3 and charging the main battery 3. The powering and regeneration of the motor 2 are performed by the control unit 10 controlling the drive circuit unit 5 based on the accelerator opening, the amount of brake pressure, etc.

[0016] The charging / discharging system 1 also includes a DC-DC converter 6 connected to the main battery 3, and an auxiliary battery 8. The DC-DC converter 6 steps down the voltage of the main battery 3 to 12 V and charges the auxiliary battery 8, which is a so-called 12 V battery, when the remaining charge of the auxiliary battery 8 is low. The auxiliary battery 8 supplies power to the above-mentioned auxiliaries 20 and a control unit 10 of the vehicle 100. The DC-DC converter 6 is also configured to be able to supply power to the auxiliaries 20 without passing through the auxiliary battery 8. Note that the DC-DC converter 6 may also supply power to the control unit 10 without passing through the auxiliary battery 8.

[0017] An AC / DC output terminal 23 is also connected to the main battery 3. This AC / DC output terminal 23 is a terminal that supplies AC current of the same voltage (e.g., 100 V) as a so-called household outlet, and in other words, it incorporates an inverter circuit (not shown) that converts DC current to AC current while stepping down the voltage of the main battery 3. Any electrical device can be connected to this AC / DC output terminal 23 as long as its power consumption does not exceed the allowable power, and in particular, a cold weather device 400 such as an electric blanket, which will be described in detail later, can be connected.

[0018] Next, the characteristics of the charge / discharge system 1 according to this embodiment will be described. The charge / discharge system 1 includes a spare battery mounting unit 21 to which a spare battery 200 can be attached (detached), and a power distributor 22 as a switching unit. The spare battery mounting unit 21 is arranged, for example, in the trunk of the vehicle 100, and is configured so that the spare battery 200 can be attached and detached. The spare battery 200 has a smaller charge capacity and size than the main battery 3, and is designed to have a lower operating temperature range (usable temperature range) than that of the main battery 3.

[0019] The spare battery 200 can be removed from the spare battery mounting section 21, and it is generally recommended that the spare battery 200 be permanently mounted in the spare battery mounting section 21. The spare battery 200 mounted in the spare battery mounting section 21 is connected only to the normal charging circuit section 7B of the charging circuit section 7, meaning that the spare battery 200 is capable of the above-mentioned normal charging but not quick charging. Generally, while quick charging is possible at service areas, commercial facilities, etc., charging of the main battery 3 of the vehicle 100 is generally assumed to be performed normally at home, for example. When the main battery 3 is charged using normal charging in this way, if the remaining charge of the spare battery 200 decreases due to natural discharge or the like, the spare battery 200 is automatically charged each time.

[0020] The spare battery 200 mounted in the spare battery mounting section 21 is connected to a power distributor 22 which is connected to the inverter 5A and the AC / DC output terminal 23. The power distributor 22 is configured to be able to disconnect the spare battery 200 from the inverter 5A and also to disconnect the spare battery 200 from the AC / DC output terminal 23, for example, by a switch (not shown) located at the driver's seat. In other words, the power distributor 22 is interposed between the drive circuit section 5 and the spare battery mounting section 21 and is configured to be manually switched between a state in which power is supplied from the spare battery 200 to the drive circuit section 5 and a state in which power is cut off. Similarly, the power distributor 22 is interposed between the AC / DC output terminal 23 and the spare battery mounting section 21 and is configured to be manually switched between a state in which power is supplied from the spare battery 200 to the AC / DC output terminal 23 and a state in which power is cut off.

[0021] The switches of the power distributor 22 may be two switches that can switch each connection individually, or one switch that switches between connecting and disconnecting both, or a dial switch that can select between disconnecting both, connecting one, connecting the other, or connecting both.

[0022] The control unit 10 performs control to disable switching of the power distributor 22 until the remaining charge of the main battery 3 falls below a predetermined remaining amount (for example, 20%), and when the remaining amount falls below the predetermined remaining amount, it enables the switch of the power distributor 22, that is, it enables manual switching, and notifies the user that the switch can be switched using, for example, a warning light or an information display. In this way, by having a passenger such as the driver perform a manual operation, the system automatically switches to the spare battery 200, preventing the spare battery 200 from running out of charge without the passenger noticing.

[0023] As described above, when the remaining charge of the main battery 3 falls below a predetermined level, normal driving using the power of the main battery 3 becomes scarce. Therefore, the driver can switch the power distributor 22 to switch from the normal driving mode, in which the vehicle runs using the power of the main battery 3, to the degenerated driving mode, in which the vehicle runs using the power of the spare battery 200. If the main battery 3 is a typical lithium-ion battery, its durability may be affected when the remaining charge falls below a predetermined level (e.g., 20% or less). Therefore, it is preferable that the control unit 10 determines that the main battery 3 is out of power when the remaining charge of the main battery 3 falls below the predetermined level (e.g., 20%), immediately prohibits use of the main battery 3, and switches the vehicle to the degenerated driving mode.

[0024] The spare battery 200 has a voltage of, for example, 200 V, which is lower than that of the main battery 3 and has a smaller maximum charge capacity. Therefore, in this degenerate traveling mode, the control unit 10 sets a maximum speed limit of, for example, 50 km / h for the vehicle 100, and allows the vehicle 100 to travel at speeds lower than this limit. By limiting the vehicle speed in this manner, the maximum driving force that can be output when powered from the spare battery 200 to drive the motor 2 is limited to a driving force lower than that when powered from the main battery 3. This eliminates the need to output a large driving force, reduces power consumption, and ensures that the distance that can be traveled by the spare battery 200 (available driving range) is maximized. Note that although the spare battery 200 has a lower voltage than the main battery 3, because the maximum driving force when the motor 2 is driven by the spare battery 200 is limited in this manner, it is not necessary to boost the voltage before supplying it to the inverter 5A or for the inverter 5A to boost the voltage.

[0025] Furthermore, in this degenerate traveling mode, when driving force is being output, the motor 2 is driven to power via the inverter 5A, but when driving force is not being output and the motor 2 is regenerated by the regenerative converter 5B, the regenerated power is sent to and charged by the main battery 3. Therefore, when traveling in this degenerate traveling mode, the remaining charge of the main battery 3 increases slightly, but this increase is used as driving power for the motor 2, together with power from the spare battery 200, when driving force is being output. In this way, even in the degenerate traveling mode, by not charging the spare battery 200 through regeneration by the motor 2, deterioration of the spare battery 200 can be prevented.

[0026] The possible cruising distance in this degenerate driving mode is, for example, 50 km on a highway, which allows the vehicle to travel under its own power to the next parking area or service area, so the charge capacity of spare battery 200 can be designed to be, for example, 3.5 kWh. Spare battery 200 with such a capacity weighs, for example, 10 kg to 20 kg, and is easily transportable even when removed from spare battery mounting section 21. Furthermore, by using spare battery 200 for self-propelled driving in this way, it can be used in place of a spare internal combustion engine power generation system such as a so-called range extender.

[0027] On the other hand, when the remaining charge of the main battery 3 falls below a predetermined level and manual switching of the power distributor 22 becomes possible, the switch of the power distributor 22 can be switched so that the power of the spare battery 200 is supplied to the AC / DC output terminal 23, and the mode can be switched from the normal terminal output mode in which the power of the main battery 3 is supplied to the AC / DC output terminal 23 to the spare terminal output mode.

[0028] This spare terminal output mode is intended, for example, for situations in which the vehicle 100 is unable to travel due to other factors (for example, traffic congestion or being stuck in a road). As described above, the accessories 20 are driven using power from the main battery 3. Therefore, when the main battery 3 runs out of charge, heating devices among the accessories 20 installed in the vehicle 100, such as an air conditioner and seat heaters, will stop operating. Therefore, assuming a situation in which the vehicle 100 is in a low-temperature environment (for example, below 0 degrees), it is considered to keep on hand low-power cold weather devices (heating devices for cold weather), such as electric blankets, that can keep occupants warm.

[0029] For example, even if five occupants use an electric blanket with a power consumption of 40 W for 12 hours each, the power consumption will be about 2.4 kWh, which is sufficient if the charge capacity of the spare battery 200 is about 3.5 kWh as described above. On the other hand, if an electric heater (e.g., a PCT heater) is used to heat the entire passenger compartment, even a medium-sized vehicle requires a heating capacity of about 5 kW, and the same 2.4 kWh of charge capacity will be consumed in about 30 minutes.

[0030] As described above, because spare battery 200 has an operating temperature range that is lower than that of main battery 3, there is no need to preheat spare battery 200 for use even when vehicle 100 is in a low-temperature environment, and the remaining charge can be used as much as possible, increasing the usage time of cold weather protection equipment and the like that protects occupants. In other words, because vehicle 100 does not require the use of cold weather protection equipment and the like that protects occupants in environments other than low-temperature environments (normal temperature environments or high-temperature environments), spare battery 200 uses a low-temperature compatible lithium-ion battery.

[0031] Generally, the internal resistance of a lithium-ion battery increases at low temperatures. This increase in internal resistance reduces the operating voltage, resulting in a decrease in power output and the inability to extract power even if a certain amount of charge remains. In a lithium-ion battery, the viscosity of the electrolyte increases at low temperatures, making it difficult for lithium ions to move and slowing down chemical reactions at the electrodes, resulting in an increase in internal resistance. Therefore, to lower the operating temperature range of a lithium-ion battery (to prevent the internal resistance from increasing even at low temperatures), an additive for low temperatures is mixed into the electrolyte to prevent the electrolyte from freezing, increasing its viscosity, and precipitating metal ions in the electrolyte. The spare battery 200 is constructed using a battery with an additive for low temperatures mixed into the electrolyte to lower the operating temperature range.

[0032] As described above, with the charge / discharge system 1 according to this embodiment, the spare battery 200 is not rapidly charged, thereby reducing the deterioration of the spare battery 200. Furthermore, in the degenerated running mode in which the vehicle runs using the motor 2 powered by the spare battery 200, the spare battery 200 is not charged during regeneration by the motor 2, thereby also reducing the deterioration of the spare battery 200. Because the deterioration of the spare battery 200 is reduced in this way, even when the remaining charge of the main battery falls below a predetermined level, that is, when it is determined that the main battery is out of power, the spare battery 200 can be used like new and can function as a spare battery.

[0033] Furthermore, according to the charging / discharging system 1 of this embodiment, the power distributor 22 can be manually switched, so that it can automatically switch to the spare battery 200, preventing the spare battery 200 from running out of charge without the occupants noticing.

[0034] Furthermore, according to the charging / discharging system 1 of this embodiment, when the remaining charge of the main battery 3 falls below a predetermined remaining amount, the inverter 5A of the drive circuit unit 5 is set to a state in which the motor 2 can be driven by supplying power from the spare battery 200. This means that the spare battery 200 is not used in the normal driving mode, and the frequency of use of the spare battery 200 can be reduced, thereby slowing down the progression of deterioration of the spare battery 200.

[0035] Furthermore, according to the charging / discharging system 1 of this embodiment, the maximum driving force that can be output when power is supplied from the spare battery 200 to drive the motor 2 is limited to a driving force that is lower than the maximum driving force that can be output when power is supplied from the main battery 3 to drive the motor 2. This eliminates the need to output a large driving force, reduces power consumption, and increases the distance that can be traveled (cruising range) using the spare battery 200.

[0036] Furthermore, according to the charging / discharging system 1 of this embodiment, the spare battery 200 has the characteristic of having a usable temperature range that is lower than the usable temperature range of the main battery 3. Therefore, even when the vehicle 100 is in a low-temperature environment, it is possible to use up as much of the remaining charge in the spare battery 200 as possible, thereby increasing the usage time of the cold weather protection equipment that protects the occupants.

[0037] In the present embodiment described above, the charging / discharging system 1 is mounted on the vehicle 100 as an electric vehicle, but this is not limited to this, and the charging / discharging system can also be used in, for example, a plug-in hybrid vehicle.

[0038] Furthermore, in this embodiment, because the progression of deterioration of spare battery 200 is reduced, spare battery 200 does not need to be replaced frequently, but if it becomes so long that it no longer functions as a spare battery, it can be removed from spare battery mounting section 21 and easily replaced. Furthermore, spare battery 200 may be removed from spare battery mounting section 21 as part of normal use, and used by connecting it to equipment when on leisure trips (for example, camping).

[0039] Furthermore, in this embodiment, the connection state of the spare battery 200 is manually switched using the power distributor 22, but this is not limiting and automatic switching is not excluded. For example, automatic switching may be performed if the vehicle is in a state that the occupant will be fully aware of (for example, a state after the vehicle has stopped due to lack of power, a state in which the speed limit is limited due to degenerate driving, a state in which the steering or accelerator operation becomes heavy unlike normal, etc.). Furthermore, switching from the main battery 3 to the spare battery 200 is not limited to when the remaining charge of the main battery falls below a predetermined level, and may be performed in any case, such as when the occupant determines it is necessary.

[0040] Furthermore, in this embodiment, when switching from the main battery 3 to the spare battery 200, the normal driving mode is switched to the degenerate driving mode. However, this is not limited to this, and if the remaining charge of the spare battery 200 is sufficiently large, the vehicle may be able to drive in the same way as in the normal driving mode.

[0041] Furthermore, in this embodiment, the spare battery 200 has been described as having an operating temperature range lower than that of the main battery 3, but this is not limited thereto, and it goes without saying that a battery having the same operating temperature range can also function as a spare.

[0042] In this embodiment, the charging / discharging system 1 includes a main battery 3, a DC-DC converter 6, Auxiliary equipment Although the above description has been given of a system including a battery 8, a rapid charging circuit unit 7A, a normal charging circuit unit 7B, a power distributor 22, an AC / DC output terminal 23, etc., these may be provided as needed; in other words, they may not be provided in the vehicle 100 in the first place, or may be provided externally to the charging / discharging system 1.

[0043] [Summary of this embodiment] This vehicle charging and discharging system (1) a rotating electric machine (2) capable of outputting driving force for running; a drive circuit unit (5) that supplies power from a main battery (3) to drive the rotating electric machine (2) and charges the main battery (3) through regeneration by the rotating electric machine (2); a control unit (10) for controlling the drive circuit unit (5); It is preferable that the backup battery (200) connectable to the drive circuit section (5) is not charged by regeneration of the rotating electric machine (2).

[0044] As a result, the spare battery 200 is not charged during regeneration by the motor 2, and the progression of deterioration of the spare battery 200 can be reduced.

[0045] In addition, the vehicle charging / discharging system (1) a normal charging circuit unit (7B) connected to a normal charger (302) and capable of charging the main battery (3); a rapid charging circuit unit (7A) connected to a rapid charger (301) capable of supplying a larger amount of power than the normal charger (302) and capable of charging the main battery (3); It is preferable that the spare battery (200) is configured so that it can be charged only from the normal charging circuit section (7B).

[0046] As a result, the spare battery 200 is not quickly charged, and the progress of deterioration of the spare battery 200 can be reduced.

[0047] In addition, the vehicle charging / discharging system (1) The spare battery (200) is preferably detachable from the spare battery mounting section (21).

[0048] This allows the spare battery 200 to be easily replaced.

[0049] In addition, the vehicle charging / discharging system (1) It is preferable to provide a switching unit (22) that is interposed between the drive circuit unit (5) and the spare battery mounting unit (21) and that can be manually switched between a state in which power is supplied from the spare battery (200) to the drive circuit unit (5) and a state in which it is cut off.

[0050] As a result, since the power distributor 22 can be switched manually, the power supply is automatically switched from the main battery 3 to the spare battery 200, and it is possible to prevent the spare battery 200 from running out of charge without the occupant noticing.

[0051] In addition, the vehicle charging / discharging system (1) It is preferable that the control unit (10) sets the drive circuit unit (5) to a state in which the rotating electric machine (2) can be driven by supplying power from the spare battery (200) when the remaining charge of the main battery (3) falls below a predetermined remaining charge.

[0052] As a result, the spare battery 200 is not used in the normal running mode, and the frequency of use of the spare battery 200 is reduced, thereby slowing down the progression of deterioration of the spare battery 200. [Industrial Applicability]

[0053] The present disclosure is industrially applicable as a vehicle charging / discharging system to be mounted on vehicles such as automobiles and trucks. [Explanation of symbols]

[0054] 1... Vehicle charging / discharging system / 2... Rotating electric machine (motor) / 3... Main battery / 5... Drive circuit section / 7A... Rapid charging circuit section / 7B... Normal charging circuit section / 10... Control section / 21... Spare battery mounting section / 22... Switching section (distributor) / 200... Spare battery / 301... Rapid charger / 302... Normal charger

Claims

1. a rotating electric machine capable of outputting driving force for running; a drive circuit unit that supplies power from a main battery to drive the rotating electric machine and charges the main battery through regeneration by the rotating electric machine; a control unit that controls the drive circuit unit; a switching unit that is interposed between the drive circuit unit and a spare battery connectable to the drive circuit unit and that can be manually switched between a state in which power is supplied from the spare battery to the drive circuit unit and a state in which power is cut off; The auxiliary battery is not charged by regeneration of the rotating electric machine, the control unit disables switching by the switching unit until the remaining charge of the main battery becomes equal to or less than a predetermined remaining charge, and enables switching by the switching unit when the remaining charge becomes equal to or less than the predetermined remaining charge. Vehicle charging and discharging system.

2. a normal charging circuit section connected to a normal charger and capable of charging the main battery; a rapid charging circuit unit connected to a rapid charger capable of supplying more power than the normal charger and capable of charging the main battery; The spare battery is configured to be charged only from the normal charging circuit unit. The vehicle charging / discharging system according to claim 1 .

3. The spare battery is detachable from the spare battery mounting section.

3. The vehicle charging / discharging system according to claim 1 or 2.

4. the control unit sets the drive circuit unit to a state in which the rotating electric machine can be driven by supplying power from the spare battery when the remaining charge of the main battery becomes equal to or less than a predetermined remaining charge. The vehicle charging / discharging system according to claim 1 .

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