JP2020018092A - Charge control device - Google Patents

Abstract

To provide a charge control device which can certainly uniformize charge amounts.SOLUTION: A charge control device charges a plurality of battery packs to be connected in parallel with one another and comprises: a charging circuit 12 which charges the respective battery packs by charge power to be supplied from an external power supply device 20; the respective contactors which electrically connect the respective battery packs with the charging circuit 12; a charge power control part 33 which controls charge power to be supplied to the charging circuit 12; a charge amount information acquisition part 32 which acquires the respective pieces of charge amount information; and a charge control part 31 which sequentially controls the start of charge from a battery pack with the lowest charge amount on the basis of the respective pieces of charge amount information, in which the charge control part 31 restricts the charge power until SOC of all the battery packs becomes approximately even after all the contactors are closed when potential difference is a first predetermined threshold T1 or more and the highest charge amount is a second threshold T2 or more at the start of charge.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a charge control device.

  In recent years, PHEV vehicles (plug-in hybrid electric vehicles) and EV vehicles (electric vehicles) have a battery system in which a plurality of battery packs (batteries) are connected in parallel in order to extend the range of the vehicle. It is being considered to increase.

  In charging such a battery system, it is necessary to shorten the charging time while ensuring safety. Therefore, when there is a difference in the amount of charge between the battery packs, the charge amount is preceded by the low charge amount battery pack. It has been proposed to charge the battery packs and charge them at the same time, and then close and contact the contactors of other high-charge battery packs connected in parallel (for example, see Patent Document 1).

  When performing the above charge control, it is difficult to measure an accurate voltage value during execution of charging of each battery pack. Therefore, it is apparent that a low charge amount battery pack is supplied with charging power from a charging circuit. At the timing when the system voltage of the high charge amount battery pack matches the voltage of the high charge amount battery pack, the contactor of the high charge amount battery pack is closed and parallel charging is started.

  Here, since the low-charge battery pack has a larger potential difference from the charging circuit than the high-charge battery pack, a larger charging current is supplied than the high-charge battery pack. Therefore, even if there is a difference in the amount of charge before charging, the voltage value between the battery packs gradually decreases with the progress of charging, that is, the amount of charge in each of the parallel-charged battery packs becomes uniform. Will be done.

JP 2015-70690 A

  However, in the charge control as described above, when the charge amount of the high-voltage battery pack at the start of charging is already high, the end of charging is determined based on the system voltage when each battery pack is connected in parallel, and the charge between battery packs is determined. There is a possibility that the charging may be terminated before the voltage equalization is completed.

  The present invention has been made in view of such a situation, and an object of the present invention is to ensure uniform charge amounts when charging a plurality of battery packs connected in parallel to each other. It is to provide a charge control device that can be used.

  A charge control device according to the present invention is a charge control device that charges a plurality of battery packs connected in parallel to each other, and a charging circuit that charges the battery pack with charging power supplied from an external power supply device; A contactor for electrically connecting a battery pack to the charging circuit; a charging power control unit for controlling the charging power supplied to the charging circuit; and a charging amount information obtaining unit for obtaining charging amount information for the battery pack A charge control unit that sequentially controls the contactor so as to start charging from the battery pack having a low charge amount among the plurality of battery packs based on the charge amount information acquired by the charge amount information acquisition unit. The charging control unit is configured to determine that at the start of charging, the potential difference between the plurality of battery packs is equal to or greater than a predetermined first threshold and When the charge amount of the battery pack having a high electric charge is equal to or greater than a predetermined second threshold value, the charge power control unit performs until the charge amounts of all the battery packs become substantially uniform after all the contactors are closed. Limiting supply of the charging power to the charging circuit;

  The charge control device increases the number of parallel charging while starting charging from a battery pack with a low charge amount in charging a plurality of battery packs, thereby ensuring safety against a potential difference between battery packs and reducing charging time. We are trying to shorten it. In addition, when the charge amount of the battery pack having the highest charge amount before charging is equal to or more than the second predetermined threshold value, the charge control device may determine that the charge amounts are substantially uniform after all the battery packs are connected in parallel. The charging power is limited only until the time is reached. Thereby, the charging control device according to the present invention does not provide a time to completely stop charging or minimizes it even during rapid charging in which an accurate voltage value of each battery pack cannot be obtained during charging, It is possible to prevent the end of charging from being determined while the amount of charge is unevenly distributed. Therefore, according to the charge control device of the present invention, when charging a plurality of battery packs connected in parallel to each other, it is possible to reliably equalize the charge amount.

1 is a system configuration diagram of an electric vehicle including a charge control device according to the present invention. FIG. 2 is a circuit diagram schematically illustrating a circuit relating to charge control of the present invention and a flow of a control signal. 4 is a flowchart illustrating charging control according to the present invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The present invention is not limited to the contents described below, and can be arbitrarily changed and implemented without changing the gist. In addition, the drawings used in the description of the embodiments each schematically show constituent members, and partial emphasis, enlargement, reduction, or omission is performed for better understanding. In some cases, the scale or shape is not accurately represented.

  FIG. 1 is a system configuration diagram of an electric vehicle including a charge control device according to the present invention. A vehicle 1 shown in FIG. 1 is a truck of an electric vehicle (that is, an electric truck) including a motor 2 as a traveling drive source. The motor 2 is a motor that can also operate as a generator, such as a permanent magnet type synchronous motor. An output shaft of the motor 2 is connected to a differential 4 via a propeller shaft 3, and left and right drive wheels 6 are connected to the differential 4 via a drive shaft 5. In addition, the vehicle 1 is not limited to a truck type, and may be a general passenger car, a bus, or another car type as long as it has a motor as a traveling drive source.

  The motor 2 is connected to a high-voltage power storage unit 13 via an inverter 10, a junction box 11, and a charging circuit 12. The DC power stored in the high-voltage power 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 driving wheels 6 to drive the vehicle 1. Further, for example, when the vehicle 1 is decelerating or traveling on a downhill road (during regenerative traveling), the motor 2 operates as a generator (regenerative operation) by reverse driving from the drive wheels 6 side. 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 Is charged to the high-voltage power storage unit 13 via the. Various contactor switches (electromagnetic contactors) for connecting / disconnecting electric circuits are provided inside the high-voltage power storage unit 13. Power supply and cutoff can be controlled.

  The junction box 11 is connected to various electric devices mounted on the vehicle 1. 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 pump of a power steering device. The high-voltage accessories 14 operate by receiving power supply from the high-voltage power storage unit 13.

  Further, a low-voltage power storage unit (both not shown) may be connected to the junction box 11 via a DC-DC converter. This makes it possible to appropriately supply power to a device driven at a low voltage, such as a VCU 30 described later.

  Further, a power receiving port 15 is connected to the junction box 11 via a power supply circuit 16. Thus, for example, in the case of quick charging, a direct current for charging the high-voltage power storage unit 13 can be supplied from the external power supply device 20 to the junction box 11. In the case of normal charging, an alternating current for charging the high-voltage power storage unit 13 can be supplied from the external power supply device 20. In the present 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 surface or the back surface of the vehicle 1, the AC current supplied from the AC power supply 23 is converted into the 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 at home, such as 100V and 200V, rapid charging, and non-contact charging can be used as appropriate.

  The power supply circuit 16 supplies the alternating 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 in the case of normal charging. For example, the power supply circuit 16 may be a circuit in which electronic components such as a coil, a diode, a transistor, and a capacitor are provided and have desired characteristics, or a circuit that simply supplies a direct current in one direction. You may. Further, 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 in 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 direct current is supplied to the charging circuit 12 from the power supply circuit 16 via the junction box 11, and the direct current is further supplied to the high-voltage power storage unit 13.

  The charging circuit 12 charges the high-voltage power 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 described in detail below. Further, 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 in the junction box 11.

  As described above, in the present embodiment, the power stored in the high-voltage power storage unit 13 is supplied to the junction box 11 via the charging circuit 12, so that 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 described later, and is a traveling power supply used for the motor 2 or the like as a driving source. The high-voltage power storage unit 13 has a predetermined operating temperature range that is appropriate for exhibiting 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 or the like.

  As shown in FIG. 1, the vehicle 1 includes an input / output device, a storage device (ROM, RAM, etc.) for storing a control program and a control map, a central processing unit (CPU), a timer counter, etc. (Not shown)). The VCU 30 according to the present embodiment is a control unit that mainly performs charging control of the high-voltage power storage unit 13, but may have another function for controlling the entire vehicle 1.

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

  Further, 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, a contact sensor is provided at the power receiving port 15, 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 and the external power supply device 20 is connected. The VCU 30 may recognize.

  Next, an operation related to charging of the high-voltage power storage unit 13 will be described more specifically with reference to FIG. FIG. 2 is a circuit diagram schematically showing a circuit relating to charging control of the present invention and a flow of a control signal. FIG. 2 shows a state in which the external power supply device 20 is connected to the vehicle 1, but the components interposed between the external power supply device 20 and the charging circuit 12 are not shown and will not be described below. . Further, in the present embodiment, the high-voltage power storage unit 13 is configured by two first battery packs P1 and second battery packs P2 connected in parallel with each other for simplification of description. .

  The first battery pack P1 includes a first contactor CON1 and a first battery module B1, both of which are connected in series. Further, the first battery module B1 has an internal resistance R. The first contactor CON1 electrically connects the first battery pack P1 to the charging circuit 12 in the closed state, and cuts off the connection between 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. The second battery module B2 has an internal resistance R. The second contactor CON2 electrically connects the second battery pack P2 to 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. Note that 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 the charge control unit 31 that individually controls the opening and closing of the first contactor CON1 and the second contactor CON2, and the individual charge information (SOC) of the first battery module B1 and the second battery module B2. And a charging power control unit 33 that controls power required for charging the high-voltage power 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 permits parallel charging by regarding that both voltages are substantially the same. . Here, the first threshold value T1 is a threshold value preset as a potential difference that ensures sufficient safety even when the first battery pack P1 and the second battery pack P2 are connected in parallel. For example, in this embodiment, it is set as 2.5V.

  The charge information acquisition unit 32 monitors the charge state of each battery module by acquiring SOC1 as charge information in the first battery module B1 and SOC2 as charge information in the second battery module B2. . 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 unit 32 of the VCU 30. Here, after transmitting the SOC value to the BGW (battery gateway: an intermediate VCU that controls each battery, not shown), the charge information obtaining unit 32 of the VCU 30 obtains the SOC information. Is also good.

The charging power control unit 33 controls the charging power supplied from the charging circuit 12 to the high-voltage storage unit 13 to a desired charging power by grasping the required charging power according to the charging state of the high-voltage storage unit 13. . Here, VCU30, to the high-voltage energy storage unit 13 in a state in which the charging circuit 12 is connected, the voltage value of the entire vehicle 1 power system, i.e. to obtain a system voltage V _S. Thus, the charging electric power control unit 33, in addition to grasp the charging power required based on the acquired system voltage V _S, it determines the charge end of high voltage energy storage unit 13 based on the system voltage V _S.

  In addition, the VCU 30 can acquire the voltage values of the first battery module B1 and the second battery module B2 as the voltage V1 and the voltage V2, respectively. Then, the VCU 30 confirms the presence or absence of a battery pack that can be connected in parallel at the start of charging, particularly by acquiring the voltage value of each battery module before the start of charging of both. However, when the voltage V1 and the voltage V2 are acquired during charging, they are dynamically changed and thus have incorrect values. Here, the presence / absence of a battery pack that can be connected in parallel may be confirmed / determined by a BGW (not shown), which is an intermediate VCU, instead of the VCU 30.

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

The VCU 30 checks the voltage V1 and the voltage V2 of each battery module before the start of charging when charging the high-voltage power storage unit 13. If the potential difference is less than the first threshold T1, the VCU 30 checks the first battery pack P1 and the The control for charging the two battery packs P2 in parallel is executed. In this case, VCU30, based on the system voltage _{V S,} while requesting the charging power required for charging the high voltage energy storage unit 13 to the external power supply device 20, the charging control unit 31 first contactor CON1 and the second Control is performed to close both contactors CON2. In addition, 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 charged by supplying charging power from the charging circuit 12, respectively.

  On the other hand, in the present embodiment, since 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, first, the second battery pack P2, which is a low charge battery pack, Quick charging starts from. That is, the charge control unit 31 (or BGW not shown) keeps the first contactor CON1 in the open state and closes the second contactor CON2.

At this time, when the voltage charging circuit 12 outputs the charging voltage V _C, since the value of the potential difference divided by the internal resistance R and the voltage V2 of the charging voltage V _C and the second battery pack P2 is the charging current, the equation of _{(V C -350) /0.1 [Ω} ] = 100 [a], the charging voltage _{V C} becomes 360 [V]. In other words, the charging circuit 12 when the voltage V2 of the second battery pack P2 is 350 [V], by outputting the 360 [V] as the charging voltage _{V C,} a constant current of 100 [A] Fast charging can be performed.

Here, the voltage value of the voltage V2 of the second battery pack P2 increases as the charging of the second battery pack P2 progresses. Therefore, the charging circuit 12, in order to maintain the charge current of 100 [A], and increases the charging voltage V _C in accordance with the increase of the voltage V2.

Charging of the second battery pack P2 progresses, the voltage V2 of the second battery pack P2 rises to 400 [V], the charging voltage _{V C} at this _{time, (V C -400) /0.1 [} Ω] From the equation of = 100 [A], it has risen to 410 [V]. At this time, 410 a charging circuit 12 for outputting a charging voltage _{V C} of [V], by a 400 [V] second battery pack P2 of, VCU30 the system as the voltage between them, approximately 405 [V] It will acquire voltage V _S.

At this time, VCU30 the potential difference between the system voltage _{V S} and the voltage V1 of the first battery pack P1 is, by which is less than the first threshold value T1, the parallel charging of the first battery pack P1 and the second battery pack P2 Is determined to be possible. That is, the charge control unit 31 (or BGW not shown) permits the 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, the first battery pack P1 between the second battery pack P2, there is a potential difference due to the influence of the output voltage V _C of the charging circuit 12. However, since the second battery pack P2 has a larger potential difference from 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. Will be. For this reason, the potential difference between the first battery pack P1 and the second battery pack P2 decreases as the charging progresses, and the charge amounts of both become uniform to reach a fully charged state.

However, if the charge amount of the first battery pack P1 before the start of charging relatively high (eg more SOC85%), before charging the amount equalization of the battery pack, charging based VCU30 within the system voltage V _S There is a possibility that the stop is determined. Therefore, the charge control device according to the present invention executes the charge control of each battery pack in accordance with the control described below, thereby completing the charge while reliably equalizing the charge amount of each battery pack.

  FIG. 3 is a flowchart showing the charging control according to the present invention. Vehicle 1 starts rapid charging of high-voltage power storage unit 13 in accordance with the charging control of FIG. 3 when charging plug 21 is inserted into power receiving port 15.

  When the 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 acquired here are accurate values because they are measured values 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 to determine whether charging has proceeded to the extent that parallel charging is possible, as described later. In addition, since the voltage value of each battery pack is constantly measured and the value is 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 above-described first threshold value T1 (Step S2). If the potential difference between the two is less than the first threshold value T1, the respective battery packs can be charged in parallel, and even if there is a difference between SOC1 and SOC2, the difference is eliminated before reaching the full charge 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 charging control unit 31 closes the first contactor CON1 and the second contactor CON2. Thereby, the quick charging in which the first battery module B1 and the second battery module B2 are connected in parallel is permitted (step S3).

Then, VCU30, while check the charge status of the high voltage energy storage unit 13 based on the system voltage V _S, determines whether the detected fully charged state (step S4). Further, when the high-voltage power storage unit 13 has reached the fully charged state, the charging control is terminated (Yes in step S4), and the charging is continued until the high voltage storage unit 13 reaches the fully charged state (No in step S4).

  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 performs 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 largest SOC among the SOCs is less than the second threshold T2 (Step S6). Here, the second threshold value T2 is a threshold value for determining whether or not there is a battery pack whose voltage before charging is already high. That is, when there is a battery pack whose SOC is higher than the second threshold value T2, when a plurality of battery packs having a potential difference equal to or more than the first threshold value T1 are rapidly charged in parallel, before the charge amounts of the battery packs are equalized. Thus, the end of charging is determined. In the present embodiment, the second threshold T2 is set, for example, as SOC 85%.

  When it is determined that the maximum SOC is less than the second threshold value T2 (Yes in step S6), the quick charge is started from the battery pack having the lowest SOC, that is, in the present embodiment, from the second battery pack P2 (step S6). S11).

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 above-described first threshold value T1 (Step S12). Here, the voltage V1 of the first battery pack P1, which is measured before charging, the potential difference between the system voltage V _S affected by the charging circuit 12 as a voltage V2 of the second battery pack P2 is, for the first threshold value T1 Be compared.

  If the potential difference between the first battery pack P1 and the second battery pack P2 is greater than or equal to the first threshold value T1 (No in step S12), it is determined that the two cannot be charged in parallel, and the rapid charging of the second battery pack P2 is performed. continue.

  Here, for example, when the high-voltage power storage unit 13 is composed of three battery packs having different charge amounts, in step S11 and step S12, by sequentially controlling each contactor, the number of parallel contacts is increased stepwise and rapidly. Charging is performed. That is, in this case, charging is first started from the low charge amount battery pack, and when the potential difference between the low charge amount battery pack and the middle charge amount battery pack becomes less than the first threshold value T1, the low charge amount battery pack and the middle charge amount The battery pack is charged in parallel with the battery pack. Further, when charging progresses until the potential difference between the low charge battery pack and the middle charge battery pack and the high charge battery pack becomes less than the first threshold value T1 (Yes in step S12), all the battery packs are connected in parallel. Connect to

  On the other hand, when it is determined that the maximum SOC is equal to or more than the second threshold value T2 (No in step S6), the quick charge is started from the battery pack having the lowest SOC, that is, in the present embodiment, from 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 above-described first threshold value T1 (Step S8). Here, the voltage V1 of the first battery pack P1, which is measured before charging, the potential difference between the system voltage V _S affected by the charging circuit 12 as a voltage V2 of the second battery pack P2 is, for the first threshold value T1 Be compared.

  If 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), it is determined that the two batteries cannot be charged in parallel yet, and the rapid charging of the second battery pack P2 is performed. continue.

  Here, for example, when the high-voltage power storage unit 13 includes three battery packs having different amounts of charge, in steps S6 and S7, the number of parallel contacts is increased stepwise by controlling each contactor sequentially to increase the number in parallel. Charging is performed. That is, in this case, charging is first started from the low charge amount battery pack, and when the potential difference between the low charge amount battery pack and the medium charge amount battery pack becomes smaller than the first threshold T1, the low charge amount battery pack and the middle charge amount The battery pack is charged in parallel with the battery pack. Further, when charging progresses until the potential difference between the low charge battery pack and the middle charge battery pack and the high charge 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 becomes smaller than the first threshold T1 (Yes in step S8), all the battery packs are connected in parallel as described above. You.

However, the battery pack, since the possibility of parallel connection is determined based on the system voltage V _S, not necessarily the SOC just because connected in parallel is uniformized. Therefore, the charging power control unit 33 of the VCU 30 changes the power request for the external power supply device 20 and limits the charging power supplied from the charging circuit to the high-voltage power 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 power storage unit 13. As a result, in the high-voltage power storage unit 13, the power is exchanged between the battery packs, so that the difference between the two SOCs 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, when it is determined that the difference between the SOCs has been eliminated (Yes in step S10), the charge control ends after the full charge through steps S3 and S4 described above.

  As described above, the charging control device according to the present invention increases the number of parallel batteries while charging the first battery pack P1 and the second battery pack P2 while starting charging from a battery pack having a low charge amount. In addition, the charging time is reduced while ensuring safety against a potential difference between the battery packs. In addition, when the charge amount of the battery pack having the highest SOC before charging is equal to or more than the predetermined second threshold value T2, the charge control device determines that the SOC is substantially uniform after all the battery packs are connected in parallel. The charging power is limited only during the period. As a result, the charge control device according to the present invention does not provide time to stop charging even during rapid charging in which accurate voltages V1 and V2 of the first battery pack P1 and the second battery pack P2 cannot be obtained during charging. Or, while minimizing the charge, it is possible to prevent the charge termination from being determined while the SOC is unevenly distributed. Therefore, according to the charge control device of the present invention, when charging a plurality of battery packs connected in parallel to each other, it is possible to reliably equalize the charge amount.

DESCRIPTION OF SYMBOLS 1 Vehicle 12 Charging circuit 13 High-voltage power 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 (1)

A charge control device that charges a plurality of battery packs connected in parallel with each other,
A charging circuit for charging the battery pack with charging power supplied from an external power supply device,
A contactor for 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 information acquisition unit for acquiring charge information of the battery pack;
Based on the charge amount information acquired by the charge amount information acquisition unit, a charge control unit that sequentially controls the contactor so as to start charging from the battery pack having a low charge amount among the plurality of battery packs, Including
The charging control unit may be configured such that, at the start of charging, the potential difference between the plurality of battery packs is equal to or greater than a predetermined first threshold, and the charge amount of the battery pack having the highest charge amount is equal to or greater than a predetermined second threshold value A charging control device that restricts the supply of the charging power from the charging power control unit to the charging circuit until the charging amounts of all the battery packs become substantially uniform after all the contactors are closed.

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