JP7137387B2 - Charging control device and electric vehicle - Google Patents

Description

The present invention relates to a charging control device and an electric vehicle .

In recent years, PHEVs (plug-in hybrid electric vehicles) and EVs (electric vehicles) have been equipped with a battery system in which multiple battery packs (batteries) are connected in parallel in order to extend the cruising range of the vehicle. It is considered to increase the

When charging such a battery system, it is necessary to shorten the charging time while ensuring safety. It has been proposed to charge the battery packs and close the contactors of the other high-charge battery packs connected in parallel after the charge amounts of the battery packs become substantially the same to charge them at the same time (see, for example, Patent Document 1).

When implementing the above charging control, it is difficult to measure the accurate voltage value during charging of each battery pack. When the system voltage and the voltage of the high charge battery pack match, the contactor of the high charge battery pack is closed and parallel charging is started.

Here, since the low charge amount battery pack has a larger potential difference from the charging circuit than the high charge amount battery pack, a larger charging current is supplied than the high charge amount battery pack. Therefore, even if there is a difference in the amount of charge between the battery packs that are charged in parallel, as the charging progresses, the voltage value between the battery packs gradually decreases, in other words, the amount of charge becomes uniform. It will be done.

JP 2015-70690 A

However, in the charging control described above, if the amount of charge in the high-voltage battery pack is already high at the start of charging, charging termination is determined based on the system voltage when each battery pack is connected in parallel, and the charging is terminated. There is a risk that the charging will end before the equalization of the voltage is completed.

SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances, and an object of the present invention is to ensure uniform charge amounts when charging a plurality of battery packs connected in parallel. To provide a charging control device capable of

A charging control device according to the present invention is a charging control device for charging a plurality of battery packs connected in parallel, comprising a charging circuit for charging the battery packs with charging power supplied from an external power supply device; a contactor that electrically connects a battery pack and the charging circuit; a charging power control unit that controls the charging power supplied to the charging circuit; and a charging amount information acquisition unit that acquires charging amount information of the battery pack. and a charging control unit that sequentially controls the contactor so that charging is started from the battery pack having the lowest charge amount among the plurality of battery packs, based on the charge amount information acquired by the charge amount information acquisition unit. , wherein the charge control unit is configured to control the potential difference between the plurality of battery packs to be equal to or greater than a predetermined first threshold and the charge amount of the battery pack having the highest charge amount to be equal to or greater than a predetermined second threshold. and restricting the supply of the charging power from the charging power control unit to the charging circuit from when all the contactors are closed until the charging amounts of all the battery packs become substantially uniform.

In charging a plurality of battery packs, the charging control device increases the number of parallel connections while starting charging from the battery pack with the lowest charge amount, thereby shortening the charging time while ensuring safety against the potential difference between the battery packs. We are trying to shorten it. In addition, the charge control device determines that, when the charge amount of the battery pack with the highest charge amount before charging is equal to or greater than a predetermined second threshold, the charge amount is substantially uniform after all the battery packs are connected in parallel. The charging power is limited until the As a result, the charging control device according to the present invention does not provide or minimize the time for completely stopping charging even during rapid charging in which an accurate voltage value of each battery pack cannot be obtained during charging. It is possible to avoid determining the end of charging while the amount of charge is unevenly distributed. Therefore, according to the charging control device of the present invention, when charging a plurality of battery packs connected in parallel, it is possible to ensure uniform charging amounts .
Further, in the charging control device according to the present invention, the charging amount information acquired by the charging amount information acquisition unit may be a pseudo system voltage in a state where at least one of the plurality of battery packs is connected to the charging circuit. .
Further, in the charging control device according to the present invention, the charging control unit restricts the charging power supply from the charging power control unit to the charging circuit by applying rapid charging in which an accurate voltage of each battery pack during charging cannot be obtained. may be implemented in some cases.
Also, an electric vehicle according to the present invention includes any one of the charging control devices described above.

1 is a system configuration diagram of an electric vehicle equipped with a charging control device according to the present invention; FIG. FIG. 2 is a circuit diagram schematically showing the flow of a circuit and control signals relating to charging control of the present invention; 4 is a flowchart showing charging control according to the present invention;

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. It should be noted that the present invention is not limited to the content described below, and can be arbitrarily changed and implemented without changing the gist of the present invention. In addition, all of the drawings used for describing the embodiments schematically show constituent members, and are partially emphasized, enlarged, reduced, or omitted for the purpose of deepening understanding. It may not represent the scale, shape, etc. accurately.

FIG. 1 is a system configuration diagram of an electric vehicle equipped with a charging control device according to the present invention. A vehicle 1 shown in FIG. 1 is an electric vehicle truck (that is, an electric truck) provided with a motor 2 as a driving source. The motor 2 is, for example, a permanent magnet type synchronous motor that can also be operated as a generator. A differential gear 4 is connected to the output shaft of the motor 2 via a propeller shaft 3 , and left and right drive wheels 6 are connected to the differential gear 4 via a drive shaft 5 . Note that the vehicle 1 is not limited to a truck type, and may be a general passenger car, bus, or other automobile type as long as it has a motor as a driving source.

The motor 2 is connected to a high voltage storage unit 13 via an inverter 10 , a junction box 11 and a charging circuit 12 . The DC power stored in the high-voltage storage unit 13 is converted into AC power by the inverter 10 and supplied to the motor 2, and the driving force generated by the motor 2 is transmitted to the drive wheels 6 to drive the vehicle 1. Further, for example, when the vehicle 1 decelerates or travels on a downhill road (during regenerative travel), the motor 2 operates as a generator by reverse driving from the drive wheels 6 (regenerative operation). The negative driving force generated by the motor 2 is transmitted to the driving wheels 6 as a braking force, and the AC power generated by the motor 2 is converted into DC power by the inverter 10, and the junction box 11 and the charging circuit 12 are operated. The high voltage storage unit 13 is charged through the . Various contactor switches (electromagnetic contactors) for connecting and disconnecting the electric circuit are provided inside the high voltage storage unit 13, and by connecting and disconnecting the contactor switch, the high voltage storage unit 13 It is possible to control the supply and cutoff of power to the

Junction box 11 is connected to various electric devices mounted on vehicle 1 . Electric power can be distributed to various electric devices by the junction box 11 .

The junction box 11 is connected to high-pressure accessories 14 such as a cooler compressor and a power steering pump. High-voltage accessories 14 operate by receiving power supply from high-voltage power storage unit 13 .

Junction box 11 may also be connected to a low-voltage power storage unit (none of which is shown) via a DC-DC converter. This makes it possible to appropriately supply power to a device driven at a low voltage, such as the VCU 30, which will be described later.

Furthermore, a power receiving port 15 is connected to the junction box 11 via a power supply circuit 16 . As a result, the junction box 11 can be supplied with a DC current for charging the high-voltage storage unit 13 from the external power supply device 20 in the case of quick charging, for example. In addition, in the case of normal charging, AC current for charging high-voltage power storage unit 13 can be supplied from external power supply device 20 . In this embodiment, the external power supply device 20 includes a charging plug 21, an AC-DC converter 22, and an AC power supply 23. With such a configuration, by inserting the charging plug 21 into the power receiving port 15 provided on the side or back of the vehicle 1, the AC current supplied from the AC power supply 23 is converted into a DC current by the AC-DC converter 22. The DC current is supplied from the charging plug 21 to the vehicle 1 . For the external power supply device 20, for example, normal charging of 100 V or 200 V for home use, quick charging, or non-contact charging can be appropriately used.

In normal charging, the power supply circuit 16 supplies AC current received from the external power supply device 20 through the power receiving port 15 to the charging circuit 12 through the junction box 11 . For example, the power supply circuit 16 may be a circuit in which electronic components such as coils, diodes, transistors, and capacitors are arranged and have desired characteristics, or may simply be a circuit that supplies direct current in one direction. may Moreover, the power supply circuit 16 may be shared with a desired circuit in the junction box 11 . That is, the power supply circuit 16 may be provided inside the junction box 11 .

A high-voltage power storage unit 13 is connected to the junction box 11 via a charging circuit 12 . With such a connection configuration, a DC current is supplied from the power supply circuit 16 to the charging circuit 12 through the junction box 11 , and the DC current is further supplied to the high-voltage storage unit 13 .

The charging circuit 12 charges the high-voltage storage unit 13 with charging power supplied from the external power supply device 20 via the power receiving port 15, the power supply circuit 16, and the junction box 11, as will be described later in detail. Moreover, the charging circuit 12 may be shared with a desired circuit in the junction box 11 . That is, the charging circuit 12 may be provided inside the junction box 11 .

As described above, in the present embodiment, the electric power stored in the high-voltage storage unit 13 is supplied to the junction box 11 via the charging circuit 12, so the charging circuit 12 also functions as a discharging circuit. Become. Note that the charging circuit and the discharging circuit may be provided independently.

The high-voltage power storage unit 13 includes a plurality of battery packs, as will be described later, and is a power source for running used for the motor 2 or the like that is a drive source. Moreover, the high-voltage power storage unit 13 has a predetermined operating temperature range that is appropriate for exhibiting its performance. Here, the number of battery packs included in high-voltage power storage unit 13 is not limited as long as it is plural, and may be appropriately changed based on the power capacity required for vehicle 1 and the like.

As shown in FIG. 1, the vehicle 1 includes an input/output device, a storage device (ROM, RAM, etc.) for storing control programs, control maps, etc., a central processing unit (CPU), a timer counter, etc. (all (not shown) is installed. The VCU 30 in the present embodiment is a control unit that mainly controls charging of the high-voltage power storage unit 13, but may be provided with other functions for performing overall control of the vehicle 1 as a whole.

The VCU 30 can acquire from the high-voltage power storage unit 13 SOC (State Of Charge) corresponding to the amount of charge in the high-voltage power storage unit 13 and information on the battery state such as battery temperature. In addition, the VCU 30 can acquire information on the progress of charging the high-voltage storage unit 13 and the like, and can also transmit a control signal for controlling the connection/disconnection of the switch in the high-voltage storage unit 13 .

Furthermore, the VCU 30 can also acquire information on whether or not the external power supply device 20 is connected from the power receiving port 15 . For example, the power receiving port 15 is provided with a contact sensor, and when the charging plug 21 contacts the power receiving port 15, a sensor signal from the contact sensor is supplied to the VCU 30, thereby indicating that the external power supply device 20 is connected. VCU 30 may recognize.

Next, referring to FIG. 2, the operation of charging the high-voltage storage unit 13 will be described more specifically. FIG. 2 is a circuit diagram schematically showing the flow of a circuit and control signals relating to charging control according to the present invention. 2 shows a state in which the external power supply device 20 is connected to the vehicle 1, components interposed between the external power supply device 20 and the charging circuit 12 are omitted from illustration and description below. . In addition, in the present embodiment, the high-voltage power storage unit 13 is composed of two, a first battery pack P1 and a second battery pack P2, which are connected in parallel for the sake of simplicity of explanation. .

The first battery pack P1 includes a first contactor CON1 and a first battery module B1, both of which are connected in series. In addition, the first battery module B1 has an internal resistance R. The first contactor CON1 electrically connects the first battery pack P1 and the charging circuit 12 in the closed state, and disconnects the first battery pack P1 and the charging circuit 12 in the open state.

The second battery pack P2 includes a second contactor CON2 and a second battery module B2, both of which are connected in series. In addition, the second battery module B2 has an internal resistance R. The second contactor CON2 electrically connects the second battery pack P2 and the charging circuit 12 in the closed state, and cuts off the connection between the second battery pack P2 and the charging circuit 12 in the open state. The number of contactors in each battery pack is not limited to one, and a plurality of contactors may be mounted.

More specifically, the VCU 30 acquires charge control unit 31 that individually controls opening and closing of the first contactor CON1 and the second contactor CON2, and individual charge amount information (SOC) of the first battery module B1 and the second battery module B2. and a charge power control unit 33 that controls the power required to charge the high-voltage storage unit 13 .

When the potential difference between the first battery pack P1 and the second battery pack P2 is less than a predetermined first threshold value T1, the charging control unit 31 assumes that the voltages of the first battery pack P1 and the second battery pack P2 are substantially the same, and permits parallel charging. . Here, the first threshold T1 is a threshold set in advance as a potential difference that can sufficiently ensure safety even when the first battery pack P1 and the second battery pack P2 are connected in parallel. , for example, is set to 2.5 V in this embodiment.

The charge amount information acquisition unit 32 acquires SOC1 as charge amount information in the first battery module B1 and SOC2 as charge amount information in the second battery module B2, thereby monitoring the charge state of each battery module. . The amount of charge in each battery module is calculated by a battery control unit (BCU) (not shown) and transmitted to the charge amount information acquisition section 32 of the VCU 30 . Here, a BGW (battery gateway: an intermediate VCU that controls each battery, not shown) is interposed to transmit the SOC value to the BGW. good too.

Charging power control unit 33 controls the charging power supplied from charging circuit 12 to high voltage storage unit 13 to desired charging power by grasping the required charging power according to the state of charge of high voltage storage unit 13 . . Here, _VCU 30 acquires the voltage value of the entire electric power system of vehicle 1, that is, system voltage VS, for high voltage power storage unit 13 to which charging circuit 12 is connected. Thereby, charging power control unit 33 determines the charging end of high voltage power storage unit 13 based on system voltage _VS as well as grasping the necessary charging power described above based on acquired system voltage _VS.

In addition, the VCU 30 can acquire the voltage values of the first battery module B1 and the second battery module B2 as voltage V1 and voltage V2, respectively. Then, the VCU 30 acquires the voltage value of each battery module particularly before the start of charging of both modules, thereby confirming the presence or absence of a battery pack that can be connected in parallel at the start of charging. However, if the voltage V1 and the voltage V2 are obtained during charging, they will be inaccurate values because they change dynamically. Here, instead of the VCU 30, a BGW (not shown), which is an intermediate VCU, may confirm and determine whether or not there are battery packs that can be connected in parallel.

Next, the basic operation of charging control according to the present invention will be described with continued reference to FIG. Here, it is assumed that the voltage V1 of the first battery module B1 is 405V and the voltage V2 of the second battery module B2 is 350V as the state before charging is started. Also, the charging circuit 12 supplies a charging current of 100 [A] to the high-voltage storage unit 13 when performing rapid charging with a constant current. Further, assume that the internal resistance R of each battery pack is 0.1 [Ω].

In charging the high-voltage power storage unit 13, the VCU 30 checks the voltage V1 and the voltage V2 of each battery module before charging is started. Control for parallel charging of two battery packs P2 is executed. In this case, the VCU 30 requests the external power supply device 20 for charging power necessary for charging the high-voltage storage unit 13 based on the system voltage _VS. Control to close both contactors CON2. Alternatively, the connection/disconnection control of the first contactor CON1 and the second contactor CON2 may be performed by a BGW (not shown), which is an intermediate VCU, instead of the VCU 30 . As a result, the first battery module B1 and the second battery module B2 are each supplied with charging power from the charging circuit 12 and charged.

On the other hand, in the present embodiment, the potential difference between the first battery module B1 and the second battery module B2 before charging is equal to or greater than the first threshold value T1. Rapid charging starts from That is, the charging control unit 31 (or the BGW not shown) keeps the first contactor CON1 open and closes the second contactor CON2.

At this time, assuming that the voltage output from the charging circuit 12 is the charging voltage VC, the charging current is the value obtained by dividing the potential difference between the charging voltage _VC and the voltage _V2 of the second battery pack P2 by the internal resistance R. From the formula (V _C -350)/0.1 [Ω]=100 [A], the charging voltage V _C is 360 [V]. In other words, when the voltage V2 of the second battery pack P2 is 350 [V], the charging circuit 12 outputs 360 [V] as the charging voltage VC, thereby charging the battery with a constant current of 100 [ _A ]. Fast charging is possible.

Here, the voltage V2 of the second battery pack P2 increases as the charging of the second battery pack P2 progresses. Therefore, in order to maintain the charging current of 100 [ _A ], the charging circuit 12 increases the charging voltage VC in accordance with the increase of the voltage V2.

When the charging of the second battery pack P2 progresses and the voltage V2 of the second battery pack P2 rises to 400 [V], the charging voltage V _C at this time is (V _C -400)/0.1 [Ω]. = 100 [A], the voltage rises to 410 [V]. At this time, the charging circuit 12 that outputs the charging voltage V _C of 410 [V] and the second battery pack P2 of 400 [V] allow the VCU 30 to generate a system voltage of approximately 405 [V] as the voltage between them. We will get the voltage _VS.

At this time, when the potential difference between the system voltage _VS and the voltage V1 of the first battery pack P1 becomes less than the first threshold value T1, the VCU 30 charges the first battery pack P1 and the second battery pack P2 in parallel. is determined to be possible. That is, the charging control unit 31 (or the BGW not shown) permits charging of the first battery pack P1 by closing the first contactor CON1.

When the first contactor CON1 and the second contactor CON2 are closed, the charging circuit 12 simultaneously charges the first battery pack P1 and the second battery pack P2 connected in parallel. However, there is a potential difference between the first battery pack P1 and the second battery pack P2 due to the influence of the output voltage _VC of the charging circuit 12 . However, since the second battery pack P2 has a larger potential difference with the charging circuit 12 than the first battery pack P1, a larger charging current is distributed to the second battery pack P2 than to the first battery pack P1. It will be. Therefore, the potential difference between the first battery pack P1 and the second battery pack P2 is reduced as the charging progresses, and the charging amounts of both are equalized to reach a fully charged state.

However, when the charge amount of the first battery pack P1 before the start of charging is relatively high (for example, SOC 85% or more), the _VCU 30 charges based on the system voltage VS before the charge amounts of the battery packs are equalized. There is a possibility that the decision to stop is made. Therefore, the charging control apparatus according to the present invention performs charging control of each battery pack according to the control described below, thereby ensuring that the charging amount of each battery pack is equalized and charging is completed.

FIG. 3 is a flow chart showing charging control according to the present invention. When charging plug 21 is inserted into power receiving port 15 , vehicle 1 starts rapid charging of high-voltage power storage unit 13 according to the charging control shown in FIG. 3 .

When charging control is started, the VCU 30 checks the voltage V1 of the first battery pack P1 and the voltage V2 of the second battery pack P2 before charging (step S1). The voltage V1 and the voltage V2 obtained here are accurate values because they are measured values in the state before the rapid charging of each battery pack is started. Then, the VCU 30 temporarily stores the voltage V1 and the voltage V2 in the state before charging, thereby determining whether the charging has progressed to the extent that parallel charging is possible as described later. Also, since the voltage value of each battery pack is constantly measured and constantly updated, the voltage value immediately before charging can be obtained. However, if the contactor is not closed after the voltage value data is updated and stored, step S1 may be performed using the stored voltage value data.

Next, the VCU 30 (or BGW not shown) determines whether the potential difference between the first battery pack P1 and the second battery pack P2 is less than the first threshold value T1 (step S2). If the potential difference between the two is less than the first threshold value T1, each battery pack can be charged in parallel, and even if there is a difference between SOC1 and SOC2, the difference is eliminated before reaching the fully charged state.

When it is determined that the potential difference between the first battery pack P1 and the second battery pack P2 is less than the first threshold value T1 (Yes in step S2), the charge control unit 31 closes the first contactor CON1 and the second contactor CON2. As a result, rapid charging in which the first battery module B1 and the second battery module B2 are connected in parallel is permitted (step S3).

Then, VCU 30 checks the state of charge of high-voltage storage unit 13 based on system voltage _VS , and determines whether or not a fully charged state has been detected (step S4). Furthermore, when the high-voltage storage unit 13 reaches the fully charged state, the charging control is terminated (Yes in step S4), and charging is continued until the fully charged state is reached (No in step S4).

Further, when it is determined that the potential difference between the first battery pack P1 and the second battery pack P2 before charging is equal to or greater than the first threshold value T1 (No in step S2), the charge amount information acquisition unit 32 of the VCU 30 obtains the first The SOC1 of the battery pack P1 and the SOC2 of the second battery pack P2 are checked (step S5).

Then, the VCU 30 determines whether the maximum SOC among the SOCs is less than the second threshold T2 (step S6). Here, the second threshold T2 is a threshold for determining whether or not there is a battery pack whose voltage is already high before charging. That is, when there is a battery pack with an SOC higher than the second threshold T2, if a plurality of battery packs with a potential difference equal to or greater than the first threshold T1 are rapidly charged in parallel, before the charging amounts of the respective battery packs are equalized , the end of charging is determined. The second threshold T2 is set as SOC 85%, for example, in the present embodiment.

If it is determined that the maximum SOC is less than the second threshold value T2 (Yes in step S6), rapid charging is started from the battery pack with the lowest SOC, that is, the second battery pack P2 in this embodiment (step S11).

Then, the VCU 30 determines whether the potential difference between the first battery pack P1 and the second battery pack P2 is less than the first threshold value T1 (step S12). Here, the potential difference between the voltage V1 of the first battery pack P1 measured before charging and the system voltage VS influenced by the charging circuit 12 as the voltage _V2 of the second battery pack P2 is be compared.

When the potential difference between the first battery pack P1 and the second battery pack P2 is equal to or greater than the first threshold value T1 (No in step S12), the second battery pack P2 is assumed to be unable to be charged in parallel yet, and the second battery pack P2 is rapidly charged. continue.

Here, for example, when the high-voltage storage unit 13 is composed of three battery packs with different charge amounts, in steps S11 and S12, by sequentially controlling each contactor, the number of parallel connections is increased step by step to rapidly Charging takes place. That is, in this case, charging is started from the low charge amount battery pack first, and when the potential difference between the low charge amount battery pack and the medium charge amount battery pack becomes less than the first threshold value T1, the low charge amount battery pack and the medium charge amount battery pack are charged. A battery pack is connected in parallel for charging. Furthermore, when charging progresses until the potential difference between the low charge amount battery pack, medium charge amount battery pack, and high charge amount battery pack becomes less than the first threshold value T1 (Yes in step S12), all battery packs are connected in parallel. connect to.

On the other hand, when it is determined that the maximum SOC is equal to or greater than the second threshold value T2 (No in step S6), rapid charging is started from the battery pack with the lowest SOC, that is, in the present embodiment, the second battery pack P2. (Step S7).

Then, the VCU 30 determines whether or not the potential difference between the first battery pack P1 and the second battery pack P2 is less than the first threshold value T1 (step S8). Here, the potential difference between the voltage V1 of the first battery pack P1 measured before charging and the system voltage VS influenced by the charging circuit 12 as the voltage _V2 of the second battery pack P2 is be compared.

When the potential difference between the first battery pack P1 and the second battery pack P2 is equal to or greater than the first threshold value T1 (No in step S8), the second battery pack P2 is assumed to be unable to be charged in parallel yet, and the second battery pack P2 is rapidly charged. continue.

Here, for example, when the high-voltage power storage unit 13 is composed of three battery packs with different charge amounts, in steps S6 and S7, the contactors are sequentially controlled to increase the number of parallel connections in a stepwise manner. Charging takes place. That is, in this case, charging is started from the low charge amount battery pack first, and when the potential difference between the low charge amount battery pack and the medium charge amount battery pack becomes less than the first threshold value T1, the low charge amount battery pack and the medium charge amount battery pack are charged. A battery pack is connected in parallel for charging. Furthermore, when charging progresses until the potential difference between the low charge amount battery pack, medium charge amount battery pack, and high charge amount battery pack becomes less than the first threshold value T1, all battery packs are connected in parallel.

Returning to the flowchart of FIG. 3, when the potential difference between the first battery pack P1 and the second battery pack P2 is less than the first threshold value T1 (Yes in step S8), all the battery packs are connected in parallel as described above. be.

However, each battery pack is determined whether or not it can be connected in parallel based on the system voltage _VS , so even if the battery packs are connected in parallel, it does not mean that the SOCs of each battery pack are equalized. Therefore, charging power control unit 33 of VCU 30 changes the power request for external power supply device 20 to limit the charging power supplied from the charging circuit to high voltage storage unit 13 (step S9). That is, the charging power control unit 33 stops or reduces the supply of charging power to the high voltage storage unit 13 . As a result, in the high-voltage storage unit 13, power is transferred between the battery packs, and the difference between the SOCs of the two is reduced.

When the charging power is limited, VCU 30 determines whether or not the difference in SOC between the battery packs has been eliminated (step S10). Then, if it is determined that the SOC difference has been eliminated (Yes in step S10), the charging control ends after full charging through steps S3 and S4.

As described above, in charging the first battery pack P1 and the second battery pack P2, the charging control device according to the present invention starts charging from the battery pack with the lowest charge amount and increases the parallel number. , the charging time is shortened while ensuring safety against the potential difference between the battery packs. In addition, when the amount of charge of the battery pack with the highest SOC before charging is equal to or greater than a predetermined second threshold value T2, the charging control device determines that the SOC is substantially uniform after all the battery packs are connected in parallel. The charging power is limited until the battery becomes full. As a result, the charging control device according to the present invention does not provide time to stop charging even in rapid charging in which the correct voltage V1 and voltage V2 of the first battery pack P1 and the second battery pack P2 cannot be obtained during charging. Alternatively, it is possible to avoid determining the end of charging while the SOC is unevenly distributed while minimizing it. Therefore, according to the charging control device of the present invention, when charging a plurality of battery packs connected in parallel, it is possible to ensure uniform charging amounts.

Reference Signs List 1 vehicle 12 charging circuit 13 high voltage storage unit 20 external power supply device 30 VCU
31 charge control unit 32 charge amount information acquisition unit 33 charge power control unit P1 first battery pack P2 second battery pack

Claims (4)

A charging control device for charging a plurality of battery packs connected in parallel,
a charging circuit that charges the battery pack with charging power supplied from an external power supply device;
a contactor electrically connecting the battery pack and the charging circuit;
a charging power control unit that controls the charging power supplied to the charging circuit;
a charge amount information acquisition unit that acquires charge amount information of the battery pack;
Based on the charge amount information acquired by the charge amount information acquisition unit , if the potential difference between the plurality of battery packs is equal to or greater than a predetermined first threshold at the start of charging, the charge amount among the plurality of battery packs a charging controller that sequentially controls the contactors to initiate charging from the battery pack with the lowest
When the charge amount of the battery pack having the highest charge amount at the start of the charge is equal to or greater than a predetermined second threshold, the charge control unit performs charging until the potential difference becomes less than the first threshold. , the charging control device, wherein the charging power control unit limits the supply of the charging power to the charging circuit from when all the contactors are closed until the charging amounts of all the battery packs become substantially uniform. 2. The charging control device according to claim 1, wherein the charging amount information acquired by said charging amount information acquisition unit is a system voltage in a state where at least one of a plurality of battery packs is connected to said charging circuit. The charging control unit restricts the charging power supply from the charging power control unit to the charging circuit when rapid charging is applied in which an accurate voltage of each battery pack during charging is not obtainable. Item 3. The charging control device according to item 1 or 2. An electric vehicle comprising the charging control device according to any one of claims 1 to 3.

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