JP2020054044A - Charge control device and charge control method - Google Patents

Abstract

To suppress overcharge to batteries.SOLUTION: A charge control device 10 is provided on a vehicle comprising a plurality of batteries 1 connected in parallel and a plurality of relay circuits 3 provided between each of the plurality of batteries 1 and a charger 20 for charging the plurality of batteries 1 and that switches between electrically connecting or not connecting each of the plurality of batteries 1 with the charger 20. The charger 20 is electrically connected with any one of the plurality of batteries 1 in turn to charge each of the plurality of batteries 1 by a predetermined amount of power. When a difference between a voltage value of a battery 1 connected with the charger 20 and a voltage value of a battery 1 not connected with the charger 20 becomes a predetermined threshold or more, the relay circuit 3 is controlled to separate the battery 1 being charged from the charger 20, and any one of the batteries 1 not connected with the charger 20 is electrically connected to the charger 20.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a charge control device and a charge control method.

  An electric vehicle is provided with a plurality of batteries connected in parallel, and these batteries are charged from a charger installed outside (for example, see Patent Document 1).

JP 2007-068285 A

  By the way, the speed of deterioration of each of the plurality of batteries may be different depending on the use state of the batteries. When a plurality of batteries connected in parallel are charged at the same time, the voltage value of the deteriorated battery quickly increases, and there is a problem that the deteriorated battery is overcharged.

  Therefore, the present invention has been made in view of these points, and an object of the present invention is to provide a charge control device and a charge control method capable of suppressing overcharging of a battery.

  A charging control device according to a first aspect of the present invention includes a plurality of batteries connected in parallel, and a plurality of batteries provided between each of the plurality of batteries and a charger for charging the plurality of batteries. A plurality of switching circuits for switching whether or not each of the plurality of batteries is electrically connected to the charger. An amount specifying unit, a voltage value specifying unit that specifies a voltage value of each of the plurality of batteries, and controlling the switching circuit to electrically connect any one of the plurality of batteries to the charger in order. And based on the charge amount specified by the charge amount specifying unit, each of the plurality of batteries is charged by a predetermined amount of power, and connected to the charger specified by the voltage value specifying unit. When the difference between the voltage value of the battery and the voltage value of the battery not connected to the charger is equal to or greater than a predetermined threshold value, the switching circuit is controlled to control the charging of the battery. And a charging control unit that disconnects one of the batteries not connected to the charger and electrically connects the battery to the charger.

The charge control unit may repeat charge control for charging each of the plurality of batteries by a predetermined amount of power.
The charging control unit may change the predetermined power amount based on a type of the charger.

  A charging control method according to a second aspect of the present invention includes a plurality of batteries connected in parallel, and a plurality of batteries provided between each of the plurality of batteries and a charger for charging the plurality of batteries. Executing a computer provided in a vehicle having a plurality of switching circuits that switch whether to electrically connect each of the plurality of the chargers, and specifying a charge amount for each of the plurality of batteries, Specifying the respective voltage values of the plurality of batteries, and controlling the switching circuit to electrically connect any one of the plurality of batteries to the charger in order, and In the step of causing the plurality of batteries to be charged by a predetermined amount of power based on the amount of charge specified in the specifying step, and the step of specifying the voltage value, Controlling the switching circuit when a difference between a voltage value of the battery connected to the charger specified in the above and a voltage value of the battery not connected to the charger becomes equal to or more than a predetermined threshold value. Disconnecting the battery being charged from the charger, and electrically connecting any one of the batteries not connected to the charger to the charger.

  ADVANTAGE OF THE INVENTION According to this invention, there exists an effect that overcharge with respect to a battery can be suppressed.

It is a figure showing composition of a vehicular electric power system concerning this embodiment. It is a figure showing composition of a charge control device concerning this embodiment. 5 is a flowchart illustrating a flow of processing when the charge control device according to the embodiment charges a plurality of batteries.

[Overview of Vehicle Power System S]
FIG. 1 is a diagram illustrating a configuration of a vehicle power system S according to the present embodiment. The vehicle power system S is mounted on a vehicle and is used to supply power to a motor unit 5 mounted on the vehicle. Although not limited, the vehicle power system S according to the present embodiment is suitably used for large electric vehicles such as buses and trucks.

  The vehicle power system S includes a plurality of batteries 1 (batteries 1A to 1C), a connection unit 2 connected to the charger 20, a plurality of relay circuits 3 (relay circuits 3A to 3C), a relay circuit 4, It includes a motor unit 5 and a charge control device 10.

  The plurality of batteries 1 are connected in parallel. Each of the plurality of relay circuits 3 is provided between the battery 1 and the charger 20 connected to the connection unit 2. In the example shown in FIG. 1, the relay circuit 3A is provided between the battery 1A and the connection unit 2, the relay circuit 3B is provided between the battery 1B and the connection unit 2, and the relay circuit 3C Is provided between the battery 1C and the connection unit 2. The plurality of relay circuits 3 switch whether or not to electrically connect the battery 1 to the charger 20 according to the control of the charging control device 10.

The relay circuit 4 is provided between the battery 1 and the motor unit 5. The relay circuit 4 switches whether or not to electrically connect the battery 1 and the motor unit 5 according to the control of the charging control device 10.
The motor unit 5 includes, for example, a motor control unit (not shown) and a motor (not shown), and operates by power supplied from the battery 1 via the relay circuit 4.

  The charging control device 10 controls the plurality of relay circuits 3 when the charger 20 installed in the charging facility is connected to the connection unit 2 and charges the plurality of batteries 1. Are sequentially connected to the charger 20 and charged by a predetermined amount of power. During the charging of the battery 1 connected to the charger 20, the charging control device 10 determines that the difference between the voltage value of the battery 1 and the voltage value of the battery 1 not connected to the charger 20 is equal to or greater than a predetermined threshold. Then, by controlling the plurality of relay circuits 3, the battery 1 being charged is disconnected from the charger, and one of the batteries not connected to the charger 20 is electrically connected to the charger 20. .

  When the degraded battery 1 is charged, the voltage value increases faster than when the undegraded battery 1 is charged. On the other hand, the charging control device 10 according to the present embodiment stops charging the battery 1 whose voltage value increases early before the charging of the predetermined amount of power is completed, and switches to charging the other battery 1. In addition, it is possible to suppress overcharging of the battery 1 in which the voltage value rises early.

[Configuration of Charge Control Device 10]
Next, the configuration of the charging control device 10 will be described. FIG. 2 is a diagram illustrating a configuration of the charge control device 10. The charge control device 10 is, for example, an ECU (Electronic Control Unit), and includes a storage unit 11 and a control unit 12, as shown in FIG.

  The storage unit 11 is, for example, a ROM (Read Only Memory) or a RAM (Random Access Memory). The storage unit 11 stores various programs for causing the control unit 12 to function.

  The control unit 12 is a calculation resource including a processor such as a CPU (Central Processing Unit) not shown. The control unit 12 functions as a charge amount specifying unit 121, a voltage value specifying unit 122, and a charge control unit 123 by executing a program stored in the storage unit 11.

  The charge amount specifying unit 121 specifies a charge amount for each of the plurality of batteries 1. For example, an ammeter (not shown) is connected to a line connected to the plurality of batteries 1. When the charger 20 is connected to the connection unit 2 and each of the plurality of batteries 1 is being charged, the charge amount specifying unit 121 determines whether the plurality of batteries 1 are based on the current value measured by the ammeter. 1 is specified. In the present embodiment, the charge amount specifying unit 121 specifies the charge amount based on the current value measured by the ammeter. However, the present invention is not limited thereto, and the charge amount may be specified by another method. .

  Voltage value specifying section 122 specifies the voltage value of each of a plurality of batteries 1. For example, a voltmeter (not shown) is connected to the plurality of batteries 1. The voltage value specifying unit 122 specifies the voltage value of each of the batteries 1 by acquiring the voltage value measured by the voltmeter.

  The charging control unit 123 controls charging of each of the plurality of batteries 1. First, when the charging control unit 123 obtains information indicating that the charger 20 has been connected to the connection unit 2 from the connection unit 2, the charging control unit 123 controls the relay circuit 4 so that the charger 20 and the plurality of batteries 1 and the motor unit Separate from 5.

  Subsequently, the charge control unit 123 controls the relay circuit 3 to electrically connect any one of the batteries 1 to the charger 20 in order, and the charge amount specified by the charge amount specifying unit 121. , Each of the plurality of batteries 1 is charged by a predetermined amount of power. The charging control unit 123 performs charging until the voltage values of the plurality of batteries 1 reach a predetermined voltage value by repeating the charging control for charging each of the plurality of batteries 1 by a predetermined amount of power.

  Specifically, the charging control unit 123 specifies the battery 1 with the lowest voltage value based on the voltage values of the plurality of batteries 1 specified by the voltage value specifying unit 122. The charging control unit 123 controls each of the plurality of relay circuits 3 to electrically connect the battery 1 having the lowest voltage value to the connection unit 2 and disconnect the other battery 1 from the connection unit 2. Subsequently, by controlling the connection unit 2, the charging control unit 123 outputs a predetermined amount of power from the charger 20 connected to the connection unit 2 to the battery 1 electrically connected to the connection unit 2. Charge.

  For example, the charging control unit 123 performs charging until the voltage value of the battery 1 to be charged first increases by a predetermined value. The charge control unit 123 sets the amount of charge to the battery 1 specified by the charge amount specifying unit 121 as a predetermined amount of power until the voltage value of the battery 1 increases by a predetermined value. Then, the charging control unit 123 charges the battery 1 to be subsequently charged with the predetermined amount of power.

  Here, the charging control unit 123 may change the predetermined power amount based on the acquired information indicating the type of the charger 20. In this case, the charging control unit 123 acquires information indicating the type of the charger 20 connected to the connection unit 2 from the connection unit 2. The type of the charger 20 indicates the charging speed of the charger 20, and includes a type indicating fast charging and a type indicating normal charging. The charging control unit 123 increases the predetermined value used to specify the predetermined amount of power when charging is started, as the charging speed indicated by the acquired information indicating the type of the charger 20 increases, thereby increasing the predetermined power. Increase the amount.

  For example, when charging is performed by the charger 20 that can perform high-speed charging, the voltage of the battery 1 may rise in a short time and significantly exceed a predetermined value. On the other hand, the charging control device 10 can set the predetermined value used when specifying the predetermined amount of power when charging is started to an appropriate value according to the type of the charger 20.

  When charging the battery 1 electrically connected to the charger 20, the charging control unit 123 electrically connects the voltage value of the battery 1 specified by the voltage value specifying unit 122 to the charger 20. The lowest voltage value among the voltage values of the battery 1 not connected is compared. The charging control unit 123 determines that the difference between the voltage value of the battery 1 connected to the charger 20 and the lowest voltage value of the battery 1 not connected to the charger 20 is a predetermined threshold value. As described above, the battery 1 being charged is separated from the charger 20 by controlling the plurality of relay circuits 3. Here, it is assumed that the predetermined threshold value is a value larger than the predetermined value used when the charging control unit 123 specifies the predetermined electric energy when charging is started.

  Then, the charging control unit 123 causes any one of the batteries 1 not electrically connected to the charger 20 to be electrically connected to the charger 20 via the connection unit 2. For example, the charging control unit 123 causes the battery 1 having the lowest voltage value among the batteries 1 not electrically connected to the charger 20 to be electrically connected to the charger 20 via the connection unit 2. After that, the charging control unit 123 charges the battery 1 electrically connected to the charger 20 with a predetermined amount of power.

  The charge control unit 123 stops charging when each voltage value of the plurality of batteries 1 reaches a predetermined voltage value. After stopping charging, the charging control unit 123 controls the relay circuit 3 and the relay circuit 4 when acquiring information indicating that the connection between the connection unit 2 and the charger 20 has been released from the connection unit 2. Are electrically connected to the motor unit 5.

[Process Flow in Charge Control Device 10]
Subsequently, a flow of processing in the charging control device 10 will be described. FIG. 3 is a flowchart illustrating a flow of processing when the charging control device 10 according to the present embodiment charges a plurality of batteries 1.

  First, the charging control unit 123 determines whether or not the charger 20 is connected to the connection unit 2 (S1). When determining that the charger 20 is connected to the connection unit 2, the charging control unit 123 shifts the processing to S <b> 2, and when determining that the charger 20 is not connected to the connection unit 2, re-executes S <b> 1.

  Subsequently, when determining that the charger 20 is connected to the connection unit 2, the charging control unit 123 controls the relay circuit 4 to disconnect the charger 20 and the plurality of batteries 1 from the motor unit 5 (S2).

Subsequently, the charging control unit 123 controls the plurality of relay circuits 3 to electrically connect one battery 1 having the lowest voltage value to the charger 20 via the connection unit 2 (S3).
Subsequently, the charging control unit 123 starts charging the battery 1 electrically connected to the charger 20 by controlling the connection unit 2 (S4).

  Subsequently, the charging control unit 123 sets the voltage value of the battery 1 electrically connected to the charger 20 and the lowest voltage value of the voltage values of the battery 1 not electrically connected to the charger 20. It is determined whether or not the difference is equal to or greater than a predetermined threshold (S5). When determining that the difference between the voltage values is equal to or more than the predetermined threshold, the charging control unit 123 shifts the processing to S7, and when determining that the difference between the voltage values is less than the predetermined threshold, shifts the processing to S6.

  Subsequently, the charge control unit 123 determines whether or not the battery 1 electrically connected to the charger 20 has been charged with a predetermined amount of power based on the charge amount specified by the charge amount specifying unit 121. (S6). If the charging control unit 123 determines that the predetermined amount of power has been charged, the process proceeds to S7, and if it determines that the predetermined amount of power has not been charged, the process proceeds to S5.

  Subsequently, the charge control unit 123 determines whether or not the voltage values of all the batteries 1 are equal to or higher than a predetermined voltage value (S7). When determining that the voltage values of all the batteries 1 are equal to or higher than the predetermined voltage value, the charging control unit 123 shifts the process to S9, and determines that the voltage values of all the battery 1 are not equal to or higher than the predetermined voltage value. The process moves to S8.

  In S8, the charging control unit 123 determines whether the connection between the connection unit 2 and the charger 20 has been released. When determining that the connection has been released, the charging control unit 123 shifts the processing to S10, and when determined that the connection has not been released, shifts the processing to S3.

  In S9, the charging control unit 123 determines whether or not the connection between the connection unit 2 and the charger 20 has been released. When determining that the connection has been released, the charging control unit 123 shifts the processing to S10, and when it is determined that the connection has not been released, re-executes S9.

  In S10, the charging control unit 123 controls the plurality of relay circuits 3 and the relay circuit 4 to electrically connect the plurality of batteries 1 and the motor unit 5 (S10).

[Effects in the present embodiment]
As described above, the charging control device 10 according to the present embodiment controls the plurality of relay circuits 3 to electrically connect any one of the plurality of batteries 1 to the charger 20 in order, Each of the plurality of batteries 1 is charged by a predetermined amount of power, and a difference between a voltage value of the battery 1 connected to the charger 20 and a voltage value of the battery 1 not connected to the charger 20 is equal to or more than a predetermined threshold value. Then, by controlling the relay circuit 3, the battery 1 being charged is disconnected from the charger 20, and one of the batteries 1 not connected to the charger 20 is electrically connected to the charger 20.

  By doing so, the charging control device 10 stops charging the battery 1 whose voltage value increases early before the charging of the predetermined power amount is completed, and switches to charging the other battery 1. It is possible to suppress overcharging of the battery 1 whose value increases early.

  In addition, the charge control device 10 performs charging until the voltage values of the plurality of batteries 1 reach a predetermined voltage value by repeating the charge control for charging each of the plurality of batteries 1 by a predetermined amount of power. By doing so, even when the connection between the connection unit 2 and the charger 20 is released during charging, the charge control device 10 sets the voltage difference between the plurality of batteries 1 to be less than the predetermined threshold. It can be.

  As described above, the present invention has been described using the embodiment, but the technical scope of the present invention is not limited to the scope described in the above embodiment, and various modifications and changes are possible within the scope of the gist. is there. For example, the specific embodiment of the dispersion / integration of the apparatus is not limited to the above embodiment, and all or a part of the apparatus may be functionally or physically dispersed / integrated in an arbitrary unit. Can be. Further, new embodiments that are generated by arbitrary combinations of the plurality of embodiments are also included in the embodiments of the present invention. The effect of the new embodiment caused by the combination has the effect of the original embodiment.

REFERENCE SIGNS LIST 1 battery 2 connection unit 3 relay circuit 4 relay circuit 5 motor unit 10 charge control device 11 storage unit 12 control unit 121 charge amount specification unit 122 voltage value specification unit 123 charge control unit 20 charger

Claims (4)

A plurality of batteries connected in parallel, and a battery provided between each of the plurality of batteries and a charger for charging the plurality of batteries; and whether or not each of the plurality of batteries is electrically connected to the charger. A charge control device provided in a vehicle including a plurality of switching circuits that switch between
A charge amount specifying unit that specifies a charge amount for each of the plurality of batteries;
A voltage value specifying unit that specifies a voltage value of each of the plurality of batteries;
By controlling the switching circuit, one of the plurality of batteries is electrically connected to the charger in order, and based on the amount of charge specified by the charge amount specifying unit, the number of the plurality of batteries Each of them is charged by a predetermined amount of power, and the difference between the voltage value of the battery connected to the charger specified by the voltage value specifying unit and the voltage value of the battery not connected to the charger is determined by a predetermined amount. When the threshold value is equal to or greater than the threshold value, by controlling the switching circuit, the battery being charged is disconnected from the charger, and one of the batteries not connected to the charger is electrically connected to the charger. A charge control unit to be connected;
A charge control device comprising: The charge control unit repeats charge control for charging each of the plurality of batteries by a predetermined amount of power,
The charge control device according to claim 1. The charging control unit changes the predetermined power amount based on a type of the charger,
The charging control device according to claim 1. A plurality of batteries connected in parallel, and a battery provided between each of the plurality of batteries and a charger for charging the plurality of batteries; and whether or not each of the plurality of batteries is electrically connected to the charger. A computer provided in a vehicle including a plurality of switching circuits for switching between the two is executed.
Identifying a charge amount for each of the plurality of batteries;
Identifying respective voltage values of the plurality of batteries;
By controlling the switching circuit, one of the plurality of batteries is electrically connected to the charger in order, and the plurality of batteries are determined based on the amount of charge specified in the step of specifying the amount of charge. Each of the batteries is charged by a predetermined amount of power, the voltage value of the battery connected to the charger specified in the step of specifying the voltage value, and the voltage of the battery not connected to the charger When the difference from the value is equal to or greater than a predetermined threshold, by controlling the switching circuit, the battery being charged is disconnected from the charger, and any one of the batteries not connected to the charger is disconnected from the battery. Electrically connecting to the charger;
A charge control method comprising:

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