JP2018107861A - Battery charge device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a battery charge device which shortens a charge time while suppressing deterioration of a battery by effectively utilizing power supplied from an external power source and is capable of improving charging efficiency of the battery.SOLUTION: A battery charge device comprises: a battery 11 which is mounted in a vehicle 1 and can be charged to a predetermined upper limit voltage; charge means 33 which charges the battery 11 by an external power source 32 of the vehicle 1; cooling means 20 which cools the battery 11; voltage detection means 40 which detects a voltage of the battery 11; and control means 40 by which, when the voltage detected by the voltage detection means 40 reaches the upper limit voltage while the battery 11 is charged, charging of the battery 11 by the charge means 33 is stopped or charge power is reduced until the detected voltage is reduced to a predetermined preset voltage. While the charging is stopped or the charge power is reduced during the charging of the battery 11, the control means 40 actuates the cooling means 20 with power from the external power source 32.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a battery charging device, and more particularly to a battery charging device mounted on an electric vehicle.

  Electric vehicles such as a hybrid (HEV) truck using an engine and a motor as driving sources and an electric (EV) truck using only a motor as a driving source are equipped with a large-capacity battery for operating the motor. . For example, Patent Document 1 discloses a vehicle charging device that charges a battery of an electric vehicle with a charger that is fed from an external power source.

  In this battery charging device, by providing various charging methods according to the situation, a decrease in battery life (deterioration) due to a large amount of current flowing through the battery due to rapid charging is suppressed. Specifically, when the battery life priority mode is selected, deterioration of the battery is suppressed by suppressing the current flowing from the external power supply to the battery via the charger to a predetermined value.

JP 2011-223796 A

  As in the conventional battery charger, simply reducing the power supplied from the external power source via the charger increases the charging time and reduces the charging efficiency. In addition, charging that is less than the rated power of the charger is performed, and the charging performance of the charger is not fully utilized. Therefore, there is still a problem to improve the charging efficiency of the battery while suppressing the deterioration of the battery by effectively using the power supplied from the external power source.

  The present invention has been made to solve at least a part of such problems, and the object of the present invention is to effectively utilize the power supplied from the external power source while suppressing deterioration of the battery. An object of the present invention is to provide a battery charger that can shorten the charging time and improve the charging efficiency of the battery.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following aspects or application examples.

(1) A battery charging apparatus according to this application example is mounted on a vehicle and can be charged to a predetermined upper limit voltage, charging means for charging the battery with an external power source of the vehicle, and cooling for cooling the battery Means, voltage detecting means for detecting the voltage of the battery, and when the voltage detected by the voltage detecting means during charging of the battery reaches the upper limit voltage, the charging is performed until the voltage drops to a predetermined set voltage. Control means for stopping charging of the battery by means or reducing charging power of the battery, while the control means stops charging or reducing charging power during charging of the battery, The cooling means is operated by electric power from the external power source.

  According to the battery charging apparatus according to this application example, when the voltage detected by the voltage detecting unit reaches the upper limit voltage during charging of the battery, the charging of the battery by the charging unit is stopped until the voltage is decreased to a predetermined set voltage. Or, by providing a control means for reducing the charging power of the battery, repeated on / off control such as stopping charging of the battery or reducing charging power, restarting charging with normal charging power thereafter, and further stopping charging or reducing charging power thereafter. Can be implemented. Thereby, compared with the case where the battery is continuously charged, as a result, the charging of the battery can be completed in a shorter time.

  Further, in the battery charging device according to this application example, the battery cooling unit is operated by the power supplied from the external power source while the charging of the battery is stopped or the charging power is reduced. This effectively utilizes the power that can be supplied from the external power supply while battery charging is stopped, and prevents the battery temperature from rising due to battery charging, while suppressing deterioration of the battery. The charging efficiency of the battery can be improved.

(2) In the battery charging apparatus according to the application example, the cooling unit includes a battery cooling circuit that cools the battery with circulating cooling water. When a battery is cooled by a water-cooled battery cooling circuit, the battery cooling effect and power consumption are larger than those of an air-cooled cooling system. Thereby, the electric power supplied from the external power source via the charging unit can be more effectively utilized for the cooling unit, and the charging efficiency can be improved by the effective cooling of the battery.

(3) In the battery charging device according to the application example, the battery cooling circuit includes a refrigerant circuit that forms a refrigeration cycle including a compressor, and the refrigerant circuit cools the cooling water using the circulating refrigerant. When a battery is cooled by a battery cooling circuit including a refrigerant circuit, the battery cooling effect and power consumption are larger than those of an air-cooled cooling system. Thereby, the electric power supplied from the external power source via the charging unit can be more effectively utilized for the cooling unit, and the charging efficiency can be improved by the effective cooling of the battery.

(4) In the battery charging device according to the application example, when the voltage detected by the voltage detecting unit becomes equal to or lower than a predetermined set voltage after stopping the charging of the battery, the control unit Charging is restarted, and after the charging is restarted, the cooling means is operated by at least part of the electric power from the external power source. Thereby, the battery which becomes high temperature nearing full charge can be charged effectively, and the charging efficiency can be improved.

  According to the battery charging device of the present invention using the application example, the battery charging capable of improving the charging efficiency of the battery while suppressing the deterioration of the battery by effectively utilizing the power supplied from the external power source. Providing the device.

It is a schematic block diagram of the battery charging device which concerns on one Embodiment of this invention. It is the figure which showed the transition of the battery voltage Vb during charge of the battery of FIG. 1, the charging power Eb supplied to a battery from a charger, the cooling power Ec for cooling a battery, and the battery temperature Tb in time series. . It is a flowchart which shows the control routine of the battery charge control which ECU of FIG. 1 performs.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic configuration diagram of a battery charging device for a hybrid vehicle according to an embodiment of the present invention, which will be described below with reference to FIG. The hybrid vehicle 1 is configured as a so-called parallel hybrid truck, and is simply referred to as a vehicle in the following description.

  A vehicle 1 is equipped with a diesel engine (hereinafter referred to as an engine) 2 as a driving power source and a motor 3 (electric motor) that can also operate as a generator. A clutch 4 is connected to the output shaft of the engine 2, and an input side of the transmission 5 is connected to the clutch 4 via a rotating shaft of the motor 3. A differential device 7 is connected to the output side of the transmission 5 via a propeller shaft 6, and left and right drive wheels 9 are connected to the differential device 7 via a drive shaft 8.

  Specifically, the motor 3 is a synchronous generator motor including a rotor on which a permanent magnet is attached and a stator around which a three-phase coil is wound, and is connected to a battery 11 via an inverter 10.

  The vehicle 1 configured as described above has the clutch 4 connected to travel by the driving force of only the engine 2, the clutch 4 is disconnected to travel by the driving force of only the motor 3, and the clutch 4 is connected to the engine 2 and Traveling by the driving force of the motor 3 is possible. For example, when the vehicle 1 decelerates or travels on a downhill road, the motor 3 operates as a generator by reverse driving from the drive wheel 9 side. The negative driving force generated by the motor 3 is transmitted to the driving wheel 9 side as a braking force, and the AC power generated by the motor 3 is converted into DC power by the inverter 10 and charged to the battery 11.

  The vehicle 1 is provided with a battery cooling circuit (cooling means) 20 that cools the battery 11. The battery cooling circuit 20 has a circulation path 20a through which the cooling water circulates, and the battery 11, the radiator 21, and the pump 22 are inserted in the circulation path 20a in the order of the flow direction of the cooling water. The battery cooling circuit 20 has a bypass path 20b that bypasses the radiator 21 in the circulation path 20a, and a heat exchanger 23 is inserted in the bypass path 20b.

  The radiator 21 includes an electric fan 24 and is a heat exchanger that cools the cooling water by exchanging heat with the outside air blown by the fan 24. The pump 22 is electric and circulates cooling water in the circulation path 20a and the bypass path 20b.

  In the battery cooling circuit 20 configured as described above, when the battery 11 is cooled, the pump 22 is driven so that the cooling water that has absorbed the heat of the battery 11 is sent to the radiator 21. In the radiator 21, the cooling water is cooled by exchanging heat between the cooling water and the outside air. Then, the sufficiently cooled cooling water is sent to the battery 11 again.

  The battery cooling circuit 20 includes a refrigerant circuit 30 having a circulation path 30a through which the refrigerant circulates. In the circulation path 30a, a heat exchanger 23, a compressor 31, a condenser (not shown), an expansion valve, and the like are inserted in order from the refrigerant flow direction. The refrigerant circuit 30 forms a refrigeration cycle that causes the heat exchanger 23 to function as an evaporator, and cools the cooling water circulating in the battery cooling circuit 20 with the refrigerant in the heat exchanger 23. The compressor 31 is an electric scroll type, for example, and adjusts the pressure of the refrigerant on the high-pressure side in the refrigeration cycle, and thus the temperature of the refrigerant.

  In the refrigerant circuit 30 configured as described above, the low-temperature refrigerant is sent to the heat exchanger 23 by driving the compressor 31 when the battery 11 is cooled. In the heat exchanger 23, the cooling water is cooled by performing heat exchange between the refrigerant and the cooling water. Then, the sufficiently cooled cooling water is sent to the battery 11 again.

  The amount of heat released from the battery 11 by the battery cooling circuit 20 varies according to the number of revolutions of the pump 22, the fan 24, and the compressor 31. For example, if the rotation speed of the pump 22 is increased, the circulation amount of the cooling water is increased, and the heat dissipation amount of the battery 11 is increased. Further, if the number of rotations of the fan 24 is increased, heat dissipation of the cooling water in the radiator 21 is promoted, and the cooling water can be maintained at a low temperature, so that the heat dissipation amount of the battery 11 increases. Further, if the rotation speed of the compressor 31 is increased, the cooling capacity related to the refrigeration cycle of the refrigerant circuit 30 is increased, the heat radiation of the cooling water in the heat exchanger 23 is promoted, and the cooling water can be maintained at a low temperature. The heat dissipation amount of 11 increases.

  The battery 11 can be connected to an external power source 32 provided outside the vehicle 1, and a charger (charging means) 33 that can supply power to the battery 11 from the external power source 32 is connected to the battery 11. The external power source 32 includes, for example, 100V and 200V ordinary charging for home use, quick charging, and non-contact charging. Although one charger 33 is shown in the present embodiment, a plurality of chargers 33 may be provided corresponding to the external power source 32.

  The vehicle 1 includes an ECU (voltage detection means, control means) 40 that manages the battery 11 including the battery cooling circuit 20. The ECU 40 is connected to a charger 33, a battery temperature sensor 41 that detects the temperature Tb of the battery 11, and an outside air temperature sensor 42 that detects the outside air temperature Ta outside the vehicle 1. Further, the ECU 40 detects the battery voltage Vb of the battery 11, the current flowing between the inverter 10 and the battery 11, and calculates the SOC (State Of Charge) of the battery 11 from these detection results.

  Further, the battery 11 is preset with an upper limit voltage Vbmax for protecting the battery 11 from application of an overvoltage. In addition, when the temperature of the battery 11 is increased due to heat generation, the performance and the life of the battery 11 are reduced. Therefore, an appropriate temperature range is determined in use.

  The ECU 40 also performs drive control of the pump 22 and the fan 24 of the battery cooling circuit 20 and the compressor 31 of the refrigerant circuit 30. The pump 22, the fan 24, and the compressor 31 are normally driven by the electric power stored in the battery 11, including during charging of the battery 11 and when the vehicle 1 is traveling. Instead, it can be directly driven by power from the external power source 32.

  Here, when a relatively long charging time (for example, 24 hours) can be secured, the ECU 40 instructs the charger 33 to charge the battery 11 at a low current value in order to suppress deterioration of the battery 11. . In this case, the battery 11 can be fully charged without accompanying the deterioration of the battery 11.

  On the other hand, when the charging time can be ensured only for a short time, the ECU 40 instructs the charger 33 to perform rapid charging at a high current value. In this case, when the battery voltage Vb approaches the upper limit voltage Vbmax, in order to protect the battery 11, the ECU 40 supplies power supplied from the external power source 32 to the charger 33 so that the battery voltage Vb does not exceed the upper limit voltage Vbmax. I have to squeeze it. In this case, only charging performance less than the rated power of the charger 33 is exhibited.

  On the other hand, as described above, the battery 11 deteriorates when it reaches a high temperature exceeding an appropriate temperature range for use. Further, in the state where the battery voltage Vb approaches the upper limit voltage Vbmax, the charging energy continues to be released due to heat, and thus the temperature rise of the battery 11 becomes significant.

  Thus, conventionally, when the battery voltage Vb is close to the upper limit voltage Vbmax, the temperature of the battery 11 is relatively high, so that the power supplied from the external power source 32 to the battery 11 is continuously reduced. In addition, out of the power supplied to the battery 11 from the charger 33, the battery 11 must also be cooled with surplus power excluding the charging power supplied while being throttled to the battery 11.

  However, in such a conventional continuous charging method, the resistance of the battery 11 is increased, and the amount of charge with respect to the charging time, that is, the charging efficiency is lowered, so that the charging performance of the charger 33 can be utilized to the maximum. In addition, it took a long time for the battery 11 to be fully charged.

  In addition, the conventional continuous charging tends to cause spontaneous discharge in the battery 11. Therefore, in order to compensate for the spontaneous discharge, the charger 33 supplies the battery 11 to the battery 11 in such a manner that a minute current is pushed in while the battery voltage Vb does not exceed the upper limit voltage Vbmax while the current from the external power supply 32 is reduced. So-called trickle charging is performed to lead the battery 11 to full charge.

  During trickle charging, almost all the power supplied to the battery 11 based on the minute current is used for cooling the battery 11 at the same time. For this reason, although the battery 11 is being charged, power that is not charged in the battery 11 is supplied from the external power source 32 to the battery 11 via the charger 33, and the charging efficiency of the battery 11 is significantly reduced. .

  Therefore, the ECU 40 of the present embodiment effectively improves the charging efficiency of the battery 11 while suppressing deterioration of the battery 11 by effectively using the power supplied from the external power source 32 via the charger 33. Battery charge control is performed.

  Specifically, as shown in FIG. 1, the charger 33 is connected not only to the battery 11 but also to a pump 22 as a cooling means, a fan 24, and a compressor 31 so as to be able to directly supply power. . At this time, the charger 33 may supply power to these components via a DC / DC converter (not shown). In the battery charging control, the charger 33 appropriately supplies power supplied from the external power source 32 to the battery 11 and the cooling unit, so that charging of the battery 11 and cooling of the battery 11 during charging are performed. Optimal power distribution is achieved.

  FIG. 2 illustrates a battery voltage Vb during charging of the battery 11, a charging power Eb supplied from the charger 33 to the battery 11, and a cooling power for cooling the battery 11 in order to explain the battery charging control of the present embodiment. It is the figure which showed transition of Ec and battery temperature Tb in time series.

  As shown in FIG. 2, in the battery charging control, when the battery voltage Vb reaches the upper limit voltage Vbmax during the charging of the battery 11, the charging of the battery 11 by the charger 33 is stopped and the battery 11 is switched from the external power supply 32 to the battery 11. The supplied charging power Eb is zero. While charging of the battery 11 is stopped, the battery 11 is driven by intentionally driving at least one of the pump 22, the fan 24, and the compressor 31 by directly using the power supplied from the external power supply 32. The electric power supplied from the external power supply 32 is consumed as the cooling electric power Ec instead of the charging electric power Eb.

  Although not shown, in the battery charging control of the present embodiment, when the battery voltage Vb reaches the upper limit voltage Vbmax during normal charging, the charging of the battery 11 by the charger 33 is not stopped, but the battery voltage Vb However, the charging power may be reduced to such a current value that causes a voltage drop that becomes equal to or lower than the set voltage Vbs1. In this case, while the charging power is being reduced, surplus power obtained by subtracting the charging power Eb of the battery from the power supplied from the external power supply 32 can be consumed as the cooling power Ec.

  After performing normal charging for charging the battery 11 without reducing the charging power and stopping the battery charging after the battery voltage Vb reaches the upper limit voltage Vbmax or reducing the charging power, as shown in FIG. In addition, a certain amount of voltage drop occurs in the battery 11. Such a voltage drop occurs particularly when charging with a relatively large current value, and the state in which the potential characteristics are biased due to a charge imbalance in the ion distribution in the electrolyte solution or active material of the battery 11 is restored. Due to that. The voltage value of the battery 11 in such a biased potential characteristic state is a voltage value including the above-described internal resistance, and a voltage value obtained by subtracting the internal resistance is a true voltage value.

  In addition, in the battery 11 in which the voltage value including the internal resistance becomes the upper limit voltage and the potential characteristic is biased, continuous charging is performed until the voltage value obtained by subtracting the internal resistance of the battery 11 reaches the upper limit voltage value. In this case, since the internal resistance is high, a very long charging time is required.

  Considering the above battery characteristics, in the battery charging control, when the battery voltage Vb reaches the upper limit voltage Vbmax during charging of the battery 11, charging of the battery 11 by the charger 33 is stopped or charging power is reduced. Thus, when the battery voltage drop is intentionally generated and the battery voltage Vb becomes equal to or lower than the set voltage Vbs1, normal charging of the battery 11 by the charger 33 is resumed.

  The set voltage Vbs1 serving as a trigger for resuming normal charging is a voltage value smaller than the upper limit voltage Vbmax, and is a voltage value at which the voltage drop of the battery 11 substantially converges. As the battery 11 approaches full charge, the set voltage Vbs1 is set so as to gradually increase, for example, as shown in FIG. 2, with the set voltage Vbs2 and the set voltage Vbs3, according to the amount of charge (SOC) of the battery 11. .

  The charging power Eb is a time-series rectangular wave in a time-series manner through repeated on / off control such as stopping charging of the battery 11 or reducing charging power, restarting charging with normal charging power thereafter, and further stopping charging or reducing charging power thereafter. It has transitioned to.

  The charging power Eb gradually decreases in both the supply time and the power value as the battery 11 approaches full charge. As described above, this is because when the battery 11 approaches full charge, the difference between the upper limit voltage and the voltage value obtained by subtracting the internal resistance of the battery 11 decreases as the SOC of the battery 11 increases. . As shown by the alternate long and short dash line in FIG. 2, the rectangular wave representing the increase or decrease in the charging power Eb is represented by a gentle approximate curve when drawn in time average, and the battery 11 is smooth and short as a whole. You can see that the battery is fully charged.

  On the other hand, the increase / decrease in the cooling power Ec of the battery 11 also changes in a time series with a stepped rectangular wave. Although the supply time of the cooling power E gradually decreases as the battery 11 approaches full charge, the power value increases. This is because, as described above, when the battery voltage Vb approaches the upper limit voltage Vbmax, the temperature rise of the battery 11 becomes significant, and thus the cooling request for the battery 11 is appropriately dealt with. As shown by the broken line in FIG. 2, the rectangular wave representing the increase / decrease in the cooling power Ec is represented by a gentle approximate curve when drawn by time average, and the battery 11 is generally viewed before full charge. It can be seen that the cooling is effective smoothly in a short time.

  Actually, the battery temperature Tb repeatedly increases and decreases while decreasing locally as the cooling power E increases within a range not exceeding the upper limit temperature Tbmax of the appropriate temperature range of the battery 11. As indicated by a two-dot chain line in FIG. 2, the upper limit value of the battery temperature Tb is represented by a gentle approximate curve, and gradually decreases as the battery 11 approaches full charge. Such a decrease in the battery temperature Tb is a preferable preparation state after the battery charging is completed, for example, before the vehicle 1 starts traveling, and contributes to the extension of the cruising distance when the vehicle 1 is traveled immediately after the battery charging is completed. It is.

  FIG. 3 is a flowchart showing a control routine for battery charging control executed by the ECU 40. Hereinafter, the battery charge control of the present embodiment will be described in detail along the flowchart of FIG.

  First, in step S1, the battery voltage Vb, the outside air temperature Ta, and the charge amount SOC at the start of the battery charge control are acquired, and the process proceeds to step S2.

  Next, in step S2, an optimum charging power Eb for guiding the battery 11 to full charge is calculated based on the battery voltage Vb, the outside air temperature Ta, the charge amount SOC, and the like, and the process proceeds to step S3.

  Next, in step S3, it is determined whether or not it is necessary to stop charging the battery 11 or reduce the charging power. Specifically, it is determined whether or not the battery voltage Vb has reached the upper limit voltage Vbmax, or whether or not the battery voltage Vb has decreased to the above-described set voltages Vbs1 to Vbs3 after reaching the upper limit voltage Vbmax. When the determination result is true (Yes), that is, when the battery voltage Vb has reached the upper limit voltage Vbmax, or after the battery voltage Vb has reached the upper limit voltage Vbmax, it has not decreased to the set voltages Vbs1 to Vbs3 described above. The process proceeds to step S4.

  Next, in step S4, based on the battery voltage Vb, the outside air temperature Ta, the charge amount SOC, etc., the optimum cooling power Ec for preventing the battery temperature Tb from exceeding the upper limit temperature Tbmax of the appropriate temperature range is calculated, and step S5. Migrate to

  Next, in step S5, charging of the battery 11 is stopped (charging power Eb = 0) or charging power is reduced. At the same time, based on the calculated cooling power Ec, the power of the external power source 32 is supplied via the charger 33 to at least one of the pump 22, the fan 24, and the compressor 31 as the cooling means, and the cooling means is driven. Then, the battery 11 is cooled and the routine returns.

  On the other hand, when the determination result is false (No) in step S3, that is, when the battery voltage Vb has not reached the upper limit voltage Vbmax, or after the battery voltage Vb has reached the upper limit voltage Vbmax, the above-described set voltages Vbs1 to Vbs1. When the voltage drops to Vbs3, the process proceeds to step S6.

  In step S6, the battery 11 is normally charged based on the calculated charging power Eb. Alternatively, when the battery voltage Vb decreases to the above-described set voltages Vbs1 to Vbs3 after reaching the upper limit voltage Vbmax, normal charging of the battery 11 is resumed. At the same time, based on the calculated cooling power Ec, power is supplied to the cooling means, the minimum cooling required for the battery 11, that is, the minimum cooling for the minimum power consumption is performed, and the routine returns.

  Thus, by repeatedly executing steps S1 to S6, the power supplied from the external power source 32 is optimally distributed for charging the battery 11 and cooling the battery 11 during charging.

  As described above, the present invention pays attention to the adverse effect that continuous long-time charging of the battery 11 increases the resistance of the battery 11 and, as a result, remarkably decreases the charging efficiency. Is to execute.

  Specifically, first, the battery voltage Vb, the charge amount SOC, the battery temperature Tb, and the like are monitored during charging (step S1). Next, after calculating the optimum charging power Eb (step S2), it is determined whether it is necessary to stop charging the battery 11 or reduce the charging power (step S3). Further, when it is determined that the charge stop or the charge power reduction is necessary, the cooling power Ec required for the battery 11 is calculated (step S4).

  Thereafter, the charging of the battery 11 is stopped or the charging power is reduced as necessary, and the cooling means such as the compressor 31 is locally driven with high power based on the calculated cooling power Ec, and the battery 11 is externally connected. The battery temperature Tb is reduced by actively cooling or pre-cooling with the power of the power source 32 (step S5).

  After that, after a certain amount of time has elapsed and the battery voltage Vb has dropped, normal charging of the battery 11 is resumed (step S6), so that the battery 11 can be more efficiently charged. Finally, the steps S1 to S6 are repeated to effectively use the power supplied from the external power supply 32, thereby shortening the charging time while suppressing the deterioration of the battery and improving the charging efficiency of the battery. be able to.

  FIG. 2 shows an example of battery charging control performed by consuming the subsequent charging power Eb by the compressor 31 or the like when the battery voltage Vb reaches the upper limit voltage Vbmax. Other elements (for example, elapsed time) other than the battery voltage Vb may be used for switching.

  In addition, as described above, the battery charging control is not limited to switching on / off of charging stop and restart of the battery 11, but may be performed by reducing charging power. Here, the reduction of the charging power may be performed by switching to a predetermined low voltage value, or may be performed by gradually reducing to a low voltage value.

  When recharging the battery 11, if the battery 11 is approaching full charge, not all of the power from the external power supply 32 is charged, but cooling means such as the compressor 31 is provided by at least a part of the power. It may be activated.

  As described above, the battery charging control of the present embodiment controls the cooling and charging during charging of the battery 11 using the cooling device such as the compressor 31 based on the battery temperature Tb, the battery voltage Vb, the charge amount SOC, and the like. In addition, by optimally allocating the power supplied from the external power supply 32 so that the rated power of the charger 33 is used up, the battery 11 can be more efficiently charged and cooled. The charging efficiency of the battery 11 is improved while suppressing deterioration due to charging and heat generation.

  This is the end of the description of the embodiment of the battery charging device according to the present invention, but the embodiment is not limited to the above embodiment.

  For example, the devices provided in the battery cooling circuit 20 of the above embodiment are not limited to those described above, and the arrangement of each device is not limited to this, and other devices may be provided or the arrangement may be changed. You may do it.

  In the battery charge control of the above embodiment, the pump 22, the fan 24, and the compressor 31 are driven at an optimal rotation speed and drive timing while the battery 11 is being charged. However, the present invention is not limited to this, and at least one of the pump 22, the fan 24, and the compressor 31, or a combination of the two may be used as long as the cooling work required for the battery 11 can be secured.

  In the battery charge control of the above embodiment, the battery 11 is cooled by the water-cooled battery cooling circuit 20, but the present invention is not limited to this, and the present invention can also be applied to the case where the battery 11 is cooled by an air-cooled cooling means. It is. However, in general, the water-cooled cooling means has a larger cooling effect and consumes more power than the air-cooled type, and is therefore suitable for application of the battery charge control.

  Further, in the above embodiment, the case where the present invention is applied to a hybrid truck has been described. However, the present invention may be applied to a hybrid bus or a passenger car, or to an electric vehicle having only a motor as a driving power source. You may do it.

1 Vehicle 11 Battery 20 Battery cooling circuit (cooling means)
30 Refrigerant circuit 31 Compressor 32 External power source 33 Charger 40 ECU (voltage detection means, control means)

Claims (4)

A battery mounted on the vehicle and chargeable up to a predetermined upper limit voltage;
Charging means for charging the battery with an external power source of the vehicle;
Cooling means for cooling the battery;
Voltage detecting means for detecting the voltage of the battery;
When the voltage detected by the voltage detecting means during the charging of the battery reaches the upper limit voltage, the charging of the battery by the charging means is stopped until the voltage is lowered to a predetermined set voltage, or the battery is charged Control means for reducing power,
The control unit is a battery charging device that operates the cooling unit with electric power from the external power source while stopping charging or reducing charging power during charging of the battery.   The battery charging device according to claim 1, wherein the cooling unit includes a battery cooling circuit that cools the battery with circulating cooling water. The battery cooling circuit includes a refrigerant circuit that forms a refrigeration cycle including a compressor,
The battery charging device according to claim 2, wherein the refrigerant circuit cools the cooling water with a circulating refrigerant.   The control means restarts charging of the battery by the charging means when the voltage detected by the voltage detecting means becomes equal to or lower than a predetermined set voltage after stopping the charging of the battery. The battery charging device according to any one of claims 1 to 3, wherein after the restart, the cooling unit is operated by at least a part of electric power from the external power source.

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