JP2009291016A - Power supply for vehicle, and vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To achieve the automatic uniform use of a plurality of energy storage devices mounted on a vehicle to supply power to a motor which is a source of driving force of the vehicle, regardless of how the user uses the vehicle. <P>SOLUTION: A power supply 10 for a vehicle includes, as a vehicle driving system, a plurality of batteries B1 to Bn connected in parallel in such a manner as to be able to supply power to a motor 12 via respective relays SMR1 to SMRn; and a battery ECU 28 for selective open/close control over the relays SMR1 to SMRn. The battery ECU 28 includes a RAM for storing a battery Bm in use for power supply at the last system operation stop. After the system stops an operation and then resumes the operation, the battery ECU selects a battery Bm+1 having a number next higher than that of the last used battery and executes control to close the relay SMRm+1 corresponding to the battery Bm+1. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a vehicle power supply device and a vehicle, and more particularly to a vehicle power supply device including a plurality of power storage devices for supplying electric power to a motor that outputs power to wheels, and a vehicle using the same.

  Conventionally, a hybrid vehicle is known as an environment-friendly vehicle. This hybrid vehicle has both an engine that is an internal combustion engine and a motor that is an electric motor as power sources that output driving force to wheels. The motor operates by being supplied with electric power from a power storage device or a battery mounted on the vehicle, thereby outputting a driving force.

  In the hybrid vehicle described above, it is conceivable that not only one power storage device but also a plurality of power storage devices are mounted to enable stable power supply. In this case, it is desirable to charge and discharge each power storage device equally. However, depending on how the user uses the vehicle, the usage state of each power storage device may be biased instead of being uniform, and there may be variations in the degree of deterioration and the life of each power storage device.

  For example, in Patent Document 1, when charging a plurality of secondary battery modules connected in parallel via a switch circuit that can be opened and closed with respect to a charging power source, the remaining capacity and the mounting order of each secondary battery module are set. Regardless, a secondary battery charging device is disclosed in which secondary battery modules are charged in the order according to the user's wishes.

  Further, in Patent Document 2, the remaining capacity is displayed for each of a plurality of storage batteries connected in parallel, and the display is confirmed, and the storage batteries to be discharged by the user are sequentially switched, thereby enabling continuous use for a long time. An enabling storage battery drive is disclosed.

JP 2004-364388 A JP-A-5-135805

  Patent Documents 1 and 2 describe that charging is performed sequentially for a plurality of secondary batteries by switching in a desired order by a user's selection operation, and a plurality of power storage devices as described above are mounted. In a hybrid vehicle, it is unrealistic and complicated and dangerous for the user to select and use the power storage device that is used, that is, to supply power, during operation of the drive system or during traveling. If the power storage device to be used is selected by the above, it is difficult to expect equal use for each power storage device.

  An object of the present invention is to provide a vehicle that automatically realizes equal use of a plurality of power storage devices mounted to supply electric power to a motor that is a driving force source of the vehicle, regardless of how the user uses the vehicle. Power supply apparatus and a vehicle using the same.

  The present invention includes first to n-th (n is a natural number of 2 or more) power storage devices connected in parallel so as to be able to supply power to a motor capable of outputting driving force of a wheel via a closed circuit portion, A vehicle power supply apparatus having a control unit that selectively controls opening and closing of a closed circuit unit as a vehicle drive system, wherein the control unit supplies power immediately before the previous system stoppage (m is 1). Or a natural number of any one of n) power storage devices, and the m + 1th power storage device (where m + 1 is 1 when m = n) when the system operation is started after the previous system operation stop. And controlling to close the open / close path corresponding to the power storage device.

  In the vehicle power supply device according to the present invention, the control unit monitors the remaining capacity of each power storage device, and supplies power when the remaining capacity of the m-th power storage device that is currently being fed falls below a predetermined value. Control for switching the power storage device from the mth power storage device to the (m + 1) th power storage device may be executed.

  The vehicle power supply device according to the present invention further includes a charging port to which a power supply member connected to a vehicle external power supply is connected in order to charge the power storage device while the system operation is stopped. The control may be performed to select the (m + 1) th power storage device to be used when the system operation is started after the previous system operation stop as a charge target and to close the open / close path corresponding to the power storage device. .

  In this case, the control unit monitors the remaining capacity of each power storage device, and when charging of the (m + 1) th power storage device that is currently being charged is completed, the power storage devices that are insufficiently charged are sequentially selected and charged. Control to switch to may be executed.

  Furthermore, a vehicle according to the present invention includes any one of the above-described vehicle power supply devices. In this case, the vehicle may further include an engine that can output the driving force of the wheels.

  According to the vehicle power supply device of the present invention, the control unit stores the m-th power storage device (m is a natural number from 1 to n) that has been supplied with power immediately before the previous system stoppage. Then, when the system operation is started after the previous system operation stop, the m + 1th power storage device is selected (where m + 1 is 1 when m = n), and control to close the open / close path corresponding to the power storage device is performed. By executing this, a power storage device different from the power storage device used last time is always selected when the system is operating. As a result, the usage states of the plurality of power storage devices can be made equal regardless of how the user uses the vehicle.

  Embodiments according to the present invention will be described below in detail with reference to the accompanying drawings. In this description, specific shapes, materials, numerical values, directions, and the like are examples for facilitating the understanding of the present invention, and can be appropriately changed according to the application, purpose, specification, and the like.

  FIG. 1 is a diagram showing a schematic configuration of a vehicle power supply device 10 according to an embodiment of the present invention. The vehicle 1 in which the vehicle power supply device 10 is incorporated has a motor 12 that can output a driving force to the wheels 2a and 2b. The rotating shaft 14 of the motor 12 is connected to the axle 18 via the differential gear portion 16, whereby the rotational driving force of the rotating shaft 14 due to the operation of the motor 12 is transmitted via the differential gear portion 16 and the axle 18. It is transmitted to the wheels 2a, 2b.

  Here, although the vehicle 1 is illustrated as having only the motor 12 as a driving force source, the vehicle power supply device 10 is not limited to an electric vehicle using only the motor as a driving force source, but uses gasoline, light oil, or the like as fuel. The present invention can also be applied to a hybrid vehicle using an internal combustion engine as a driving force source. In this case, a motor is further provided as a generator that generates electric power by distributing power from the engine, and the electric power generated by the motor is converted from an AC voltage to a DC voltage by an inverter, and then to each battery described later. It is charged or supplied directly as drive power for the motor 12.

  A three-phase synchronous motor is preferably used for the motor 12. One end of each of the U-phase, V-phase, and W-phase coils constituting a part of the stator of the motor 12 is commonly connected to the neutral point N, while the other end of each phase coil is a voltage converter. 20 are electrically connected to each other. Voltage converter 20 includes an inverter that converts a DC voltage supplied from a secondary battery, which is a power storage device described later, into a three-phase AC voltage that is a motor applied voltage. Voltage converter 20 further includes a boost converter that boosts the DC voltage supplied from the secondary battery to a voltage value within a range up to a predetermined upper limit value. In the voltage converter 20 including these inverter and boost converter, the included power switching element (for example, IGBT) is controlled on / off based on a command from a motor ECU (Electronic Control Unit, the same applies hereinafter) 22. Thus, the DC / AC conversion function and the boosting function are executed. In addition, the said inverter and a boost converter can use a thing of a known structure, and abbreviate | omits detailed description here.

  The motor 12 can also function as a generator during regeneration such as braking and deceleration of the vehicle 1. The electric power generated by the motor 12 is converted from an AC voltage to a DC voltage by the inverter in the voltage converter 20 and then stepped down by the converter, and then charged to each battery described later.

  The vehicle power supply device 10 is connected to the power line 24 and the ground line 26 connected to the voltage converter 20 in parallel via corresponding system main relays (switching path portions) SMR1, SMR2,. First to nth batteries (hereinafter also referred to as “batteries” as appropriate) B1, B2,..., Bn as the electrically connected power storage devices, and the system main relays (opening / closing path portions) SMR1, SMR2 ,... Includes a battery ECU (control unit) 28 that selectively controls on (closed) and off (open) SMRn. Here, although at least three or more batteries are shown in FIG. 1, the “n” may be a natural number of 2 or more. For example, only two batteries B1 and B2 may be used. Moreover, although secondary batteries, such as a lithium ion battery and a nickel hydride battery, are used suitably for each battery B1, B2, ..., Bn, a capacitor etc. may be used as an electrical storage apparatus in addition to that.

  The battery ECU 28 is a CPU that executes a control program, a ROM that stores a control program, parameter threshold values, and the like in advance. The battery ECU 28 temporarily supplies data such as a battery number by supplying power immediately before or when the system is stopped. A readable RAM (storage unit) and the like are included.

  Each battery B1, B2,..., Bn is provided with a current sensor 30 for detecting the battery current. The battery ECU 28 monitors the remaining capacity (SOC (State Of Charge)) for each of the batteries B1, B2,..., Bn by integrating the battery current input from each current sensor 30. .

  The vehicle 1 further includes a main ECU 32. A power switch 34, a vehicle speed sensor 36, and an accelerator opening sensor 38 are electrically connected to the main ECU 32, respectively. The power switch 34 is, for example, a push button type switch that is installed at a position that can be easily operated by a user sitting in the driver's seat of the vehicle 1. When the power switch 34 is turned on, the motor 12, the voltage converter 20, each battery B <b> 1. , B2,..., Bn, system main relays SMR1, SMR2,. The drive system is deactivated. Further, the main ECU 32 obtains a vehicle required torque based on the vehicle speed inputted from the vehicle speed sensor 36 and the accelerator opening inputted from the accelerator opening sensor 38, and the driving force corresponding to the vehicle required torque is obtained from the motor 12. A torque command is transmitted to the motor ECU 22 so as to be output. Further, the main ECU 32 is also electrically connected to the battery ECU 28 so as to be communicable, and various data such as remaining capacity for each of the batteries B1, B2,..., Bn, battery voltage and battery temperature detected by a sensor (not shown), and the like. On the other hand, an on / off signal of the power switch 34 is transmitted.

  Next, the operation and control of the vehicle power supply device 10 will be described with reference to FIG. FIG. 2 is a flowchart showing a control procedure executed in battery ECU 28. This control is started when, for example, the electromagnetic lock of the vehicle door is released by the control of the main ECU 32.

  First, it is determined whether or not the power switch 34 has been turned on (step S10). This determination is made based on whether or not an ON signal indicating that the power switch 34 is turned ON by the user is received from the main ECU 32. If the ON signal cannot be received even after a predetermined time has elapsed (NO in step S10), the process ends.

  On the other hand, when the power switch 34 is turned on (YES in step S10), which battery to use is selected from the n batteries B1 to Bn (step S12). At this time, since the battery number used for power supply at the time of the previous system operation stop for the vehicle drive system is stored in the RAM, the battery number used at the time of the previous system operation stop is m (m is 1 to 1). n is a natural number), that is, when the m-th battery Bm was the last used battery, the m + 1-th battery Bm + 1, which is the next higher-order battery, is selected as the current power supply battery. Thereby, battery ECU 28 turns on system main relay SMRm + 1 corresponding to battery Bm + 1 to enable power supply from battery Bm + 1 to motor 12.

  When the use battery is selected in this way, the battery number m + 1 is stored in the RAM and the use battery storage is updated (step S14). Then, electric power is supplied from the (m + 1) -th battery Bm + 1 according to the accelerator operation by the user (step S16), whereby the motor 12 is activated and the driving force is output.

  Next, it is determined whether or not the remaining capacity SOC of the (m + 1) th battery Bm + 1 in use has decreased to a predetermined threshold, for example, less than 40% of the rated capacity (step S18). If the SOC is 40% or more (NO in step S18), it is determined whether or not the power switch 34 is turned off (step S24). If the power switch 34 is not turned off (step S24). NO), returning to step S16, the use of the (m + 1) th battery Bm + 1 is continued.

  As described above, when the SOC of the (m + 1) th battery Bm + 1 becomes less than 40% while repeating the processes of steps S16, S18, and S24 (YES in step S18), the used battery is the next higher-order battery, that is, Switch to the m + 2 battery (step S20). At this time, system main relay SMRm + 2 is turned on to enable power supply from m + 2 battery Bm + 2, and then system main relay SMRm + 1 is turned off. Further, when the nth battery Bn is used and the SOC becomes less than 40%, the next battery to be used is switched to the first battery B1.

  When the used battery is switched as described above, the used battery number stored in the RAM is updated to m + 2 and stored (step S22). Thereafter, similarly to the above, it is determined whether or not the power switch 34 is turned off (step S24), and the processes of steps S16 to S24 are repeatedly executed until the power switch 34 is turned off. When the power switch 34 is turned off (YES in step S24), the vehicle drive system is deactivated. At that time, the battery number of the battery that has been in use until the system deactivation is stored in the RAM as the last used battery. It will be in the state.

  As described above, according to the vehicle power supply device 10 of the present embodiment, the used battery that was supplied with power when the system operation was stopped or immediately before is stored, and then the power switch 34 is turned on. When the system operation starts, the battery with the next highest number after the last used battery is selected as the used battery. Therefore, when the system is operated, a battery different from the battery that was used last time is always selected. As a result, regardless of how the vehicle 1 is used by the user, the usage state of the n batteries B1 to Bn is changed. Can be even.

  Next, with reference to FIG. 3 and FIG. 4, the power supply device 11 for vehicles of another embodiment is demonstrated. FIG. 3 is a diagram showing a schematic configuration of the vehicle 1 including the vehicle power supply device 11. Since the vehicular power supply device 11 has substantially the same configuration as the vehicular power supply device 10, the same constituent elements are denoted by the same reference numerals, and redundant explanations are omitted. The differences will be mainly described.

  The vehicle power supply 11 includes first to nth batteries B1, B2,... Electrically connected in parallel to the motor 12 as a load via the system main relays SMR1, SMR2,. .., Bn and a battery ECU 28 for selectively turning on / off the system main relays SMR1, SMR2,..., SMRn, and covered with a cover member that can be opened and closed on the side or rear of the body of the vehicle 1 It further includes a power supply port 44 installed. The power supply port 44 is electrically connected to the neutral point N of the motor 12. Thus, when the plug 42 electrically connected to the vehicle external power supply 40 is connected to the power supply port 44 while the vehicle 1 is stopped and the system is stopped, the electric power input from the power supply port 44 is converted to the motor 12 and the voltage conversion. The batteries B1 to Bn are charged via the container 20. The vehicle external power source 40 may be a household AC power source (AC 100 volts) or a higher-voltage industrial AC power source. In this case, the AC voltage supplied from the power supply port 44 via the motor 12 is converted into a DC voltage by the inverter in the voltage converter 20, and is stepped down by the converter as necessary, and then charged to each of the batteries B1 to Bn. The

  Although the vehicle 1 on which the vehicle power supply device 11 is mounted is illustrated as having only the motor 12 as a driving force source, the vehicle power supply device 11 is limited to an electric vehicle using only the motor as a driving force source. The present invention is also applicable to a hybrid vehicle that uses an engine that is an internal combustion engine that uses gasoline, light oil, or the like as a fuel as a driving force source. Such a hybrid vehicle is sometimes called a “plug-in hybrid vehicle”.

  Next, with reference to FIG. 4, the operation and control of the vehicle power supply device 11 configured as described above will be described. FIG. 4 is a flowchart showing a control procedure executed in battery ECU 28. This control is started when, for example, the electromagnetic lock of the cover covering the power supply port 44 is released by the control of the main ECU 32.

  First, it is determined whether charging has started (step S30). This determination is based on an input signal from a plug detection sensor (not shown) that is disposed in the vicinity of the power supply port 44 and detects the connection of the plug 42, or a voltage sensor that detects that power is input from the power supply port 44. This is performed based on an input signal from (not shown).

  If the cover is closed and electromagnetically locked without the plug 42 being inserted into the power supply port 44 (NO in step S30), the process is terminated. On the other hand, when charging is started (YES in step S30), a battery to be charged is selected (step S32). Here, the battery to be used when the power switch 34 is turned on next time to start the system operation is selected. Describing along the example of the vehicle power supply device 10 described above, if the battery used at the time of the previous system operation stop is the m-th battery Bm, the battery used at the start of the next system operation is the m + 1-th battery Bm + 1. Since it is selected, this (m + 1) th battery Bm + 1 is selected as the charging target.

  Thus, when the (m + 1) th battery Bm + 1 is selected as the charging target, the corresponding system main relay SMRm + 1 is turned on. As a result, the power supplied from the power supply port 44 is charged to the (m + 1) th battery Bm + 1 via the motor 12 and the voltage converter 20 (step S34).

  Then, it is determined whether or not charging of the (m + 1) th battery Bm + 1 is completed (step S36). Here, it is determined that the charging is completed when the SOC of the (m + 1) th battery Bm + 1 reaches 80% of the rated capacity.

  When charging of the (m + 1) -th battery Bm + 1 is completed (YES in step S36), the system main relay SMRm + 1 is turned off, and then it is determined whether or not there is an insufficiently charged battery (step S38). Here, it is determined that the battery whose SOC monitored by the battery ECU 28 is less than 80% is insufficiently charged.

  If there is no insufficiently charged battery (NO in step S38), the process is terminated as it is. On the other hand, if there is an undercharged battery (YES in step S38), the system main relay corresponding to the undercharged battery is turned on to switch the charge battery (step S40). At this time, when there are a plurality of undercharged batteries, charging may be performed in order of switching during system operation, that is, in order from the battery with the smallest battery number, or charging in order from the lowest SOC. Also good.

  When the processes in steps S34 to S40 are repeated and charging is completed for all the batteries B1 to Bn (NO in step S38), the system main relay corresponding to the last charged battery is turned off and the process is terminated.

  Thus, according to the vehicle power supply device 11 of the present embodiment, in addition to the same effects as the vehicle power supply device 10 described above, the vehicle power supply device 11 is first used when the system operation is started by the next ON operation of the power switch 34. Since the battery to be charged is charged, the next system operation start can be more reliably executed.

  In the above vehicle power supply device 11, the power supply port 44 is electrically connected to the neutral point N of the motor 12. However, the present invention is not limited to this. An electrical connection may be made and this charge-only voltage converter may be electrically connected to the power line 24 and the ground line 26. In this case, the AC voltage input from the power supply port 44 is converted into a DC voltage by the charge voltage converter described above, and is stepped up or stepped down as necessary before being charged into the batteries B1 to Bn.

1 is a diagram illustrating a schematic configuration of a vehicle including a vehicle power supply device according to an embodiment of the present invention. It is a flowchart which shows the control procedure performed in the vehicle power supply device of FIG. It is a figure which shows schematic structure of the vehicle containing the vehicle power supply device of another embodiment of this invention. It is a flowchart which shows the control procedure performed in the vehicle power supply device of FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Vehicle, 2a, 2b Wheel, 10, 11 Vehicle power supply device, 12 Motor, 14 Rotating shaft, 16 Differential gear part, 18 Axle, 20 Voltage converter, 22 Motor ECU, 24 Power line, 26 Ground line, 28 Battery ECU, 30 Current sensor, 32 Main ECU, 34 Power switch, 36 Vehicle speed sensor, 38 Accelerator opening sensor, 40 Vehicle external power supply, 42 Plug, 44 Power supply port, B1-Bn battery, SMR1-SMRn System main relay, N Neutral point.

Claims (6)

First to nth (n is a natural number of 2 or more) power storage devices connected in parallel so as to be able to supply power to the motors capable of outputting the driving force of the wheels via the closed circuit part, and the closed circuit part A vehicle power supply apparatus having a control unit that selectively controls opening and closing as a vehicle drive system,
The control unit includes a storage unit that stores an m-th power storage device (m is a natural number of 1 to n) that has been supplied with power immediately before the previous system operation stop. When the operation is started, the m + 1th power storage device is selected (where m + 1 is 1 when m = n), and control for closing the open / close path corresponding to the power storage device is executed. Power supply. The vehicle power supply device according to claim 1,
The control unit monitors the remaining capacity of each power storage device, and when the remaining capacity of the m-th power storage device that is currently being fed falls below a predetermined value, the power storage device that supplies power from the mth power storage device A vehicular power supply device that performs control to switch to an m + 1 power storage device. The vehicle power supply device according to claim 1,
In order to charge the power storage device while the system is stopped, the battery pack further includes a charging port to which a power supply member connected to a vehicle external power source is connected.
The control unit performs control for selecting the m + 1-th power storage device to be used when the system operation is started after the previous system operation stop as a charging target and closing the open / close path corresponding to the power storage device. A power supply device for a vehicle. In the vehicle power supply device according to claim 3,
The control unit monitors the remaining capacity of each power storage device, and when charging of the currently charged m + 1th power storage device is completed, performs control to switch the power storage devices that are insufficiently charged in order to be charged. A power supply device for a vehicle that is executed.   A vehicle comprising the vehicle power supply device according to any one of claims 1 to 4.   6. The vehicle according to claim 5, further comprising an engine capable of outputting wheel driving force.

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