JP6535583B2 - Power supply for vehicles - Google Patents

Description

  The present invention relates to a power supply device for a vehicle including a first power storage unit and a second power storage unit.

  As electric vehicles that can be charged by an external power source, not only electric vehicles equipped with only a motor generator as a power source, but also hybrid electric vehicles equipped with a motor generator and an engine as a power source. These electric vehicles have a high voltage system provided with a high voltage battery for supplying power to a motor generator and a low voltage system provided with a low voltage battery for supplying power to a controller and accessories. (See Patent Document 1). In addition, when charging the high voltage battery with the external power supply, it is necessary to start the controller for charge control, so power is supplied from the high voltage system to the low voltage system via the power converter such as a converter. ing.

JP, 2011-87408, A

  By the way, when supplying electric power from a high voltage system to a low voltage system, when the temperature of a power converter rises excessively, it is necessary to stop a power converter from a viewpoint of protecting a power converter. As described above, stopping the power converter to cut off the power supply to the low voltage system is a factor to reduce the power supply voltage of the controller, and is a factor to stop the controller. In addition, stopping the charge control controller is a factor for stopping the charging by the external power supply, and is a factor for extending the charging time of the high voltage battery.

  An object of the present invention is to suppress the extension of the charging time.

  The vehicle power supply device according to the present invention is a vehicle power supply device including a first power storage body and a second power storage body having a voltage lower than that of the first power storage body, and the external power supply is used to charge the first power storage body. A first power supply provided between a power supply connection unit to which the external power supply is connected, the first power storage unit, and the second power storage unit, and supplying power from the first power storage unit to the second power storage unit; A converter, a second power converter provided between the power supply connection portion and the second power storage body, which supplies power from the power supply connection portion to the second power storage body, and the external power supply connection portion; A first supply mode for supplying power to the second storage via the first power converter during external charging to which a power supply is connected, and power on the second storage via the second power converter And a second supply mode for supplying Switches between the second supply mode and the first supply mode based on temperature.

  According to the present invention, the mode control unit supplies power to the second power storage body via the first power converter, and supplies power to the second power storage body via the second power converter. Switching to the second supply mode to be performed based on the temperature. Thereby, at the time of external charging in which the external power supply is connected to the power supply connection portion, charging of the first power storage body by the external power supply can be continued, and extension of the charging time of the first power storage body can be suppressed.

BRIEF DESCRIPTION OF THE DRAWINGS It is the schematic which shows the power supply device for vehicles which is one embodiment of this invention. It is a flowchart which shows an example of the execution procedure of mode switching control. It is explanatory drawing which shows the electric power supply condition when 1st supply mode is performed during external charge. It is explanatory drawing which shows the electric power supply condition when 2nd supply mode is performed during external charge. It is the schematic which shows the structure of the power supply device for vehicles which is other embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described in detail based on the drawings. FIG. 1 is a schematic view showing a vehicular power supply device 10 according to an embodiment of the present invention. The illustrated vehicle power supply device 10 is applied to an electric vehicle that can be charged by an external power supply. As such an electric vehicle, for example, there is an electric vehicle equipped with only a motor generator as a power source, and there is a hybrid type electric vehicle equipped with a motor generator and an engine as a power source.

  As shown in FIG. 1, the vehicle power supply device 10 includes a high voltage battery (first power storage body) 11. A high voltage system 13 for supplying power to the motor generator 12 is connected to the high voltage battery 11. High voltage system 13 includes an inverter 15 connected to high voltage battery 11 via energization line 14, and a motor generator 12 connected to inverter 15 via energization line 16. Drive wheels 17 are connected to the motor generator 12 via a drive system (not shown). At the time of acceleration of the vehicle which causes motor generator 12 to perform power running, DC power is converted to AC power by inverter 15, and power is supplied from high voltage battery 11 to motor generator 12. On the other hand, at the time of vehicle deceleration for regenerating motor generator 12, AC power is converted to DC power by inverter 15, and power is supplied from motor generator 12 to high voltage battery 11.

  Further, an external charging system 21 to which power is supplied from the external power supply 20 is connected to the high voltage battery 11. The external charging system 21 has a charger 23 connected to the high voltage battery 11 via the conduction line 22, and an inlet (power supply connection portion) 25 connected to the charger 23 via the conduction line 24. ing. When charging the high voltage battery 11 using the external power supply 20, the connector 27 of the charging cable 26 is connected to the inlet 25, and the plug 28 of the charging cable 26 is connected to the outlet 29 of the external power supply 20. Thus, when the external power supply 20 is connected to the inlet 25, AC power is converted to DC power by the charger 23, and power is supplied from the external power supply 20 to the high voltage battery 11 via the charger 23. The charger 23 is a so-called AC-DC converter including a plurality of switching elements and the like, and has a function of converting AC power into DC power.

  The vehicle power supply device 10 has a low voltage system 32 including a low voltage battery (second power storage unit) 30 and a vehicle load 31. The low voltage battery 30 is designed to have a lower voltage than the high voltage battery 11. The low voltage system 32 is connected to the high voltage system 13 via the main converter 33 and connected to the external charging system 21 via the sub converter 34. That is, the high voltage system 13 is connected to the input terminal of the main converter 33 via the conduction line 35, and the low voltage system 32 is connected to the output terminal of the main converter 33 via the conduction line 36. Further, the external charging system 21 is connected to the input terminal of the sub converter 34 via the conduction line 37, and the low voltage system 32 is connected to the output terminal of the sub converter 34 via the conduction line 38.

  Thus, a main converter 33, which is a first power converter, is provided between the high voltage battery 11 constituting the high voltage system 13 and the low voltage battery 30 constituting the low voltage system 32. By operating the main converter 33, power is supplied from the high voltage battery 11 to the low voltage battery 30. Further, a sub-converter 34, which is a second power converter, is provided between the inlet 25 of the external charging system 21 and the low voltage battery 30 of the low voltage system 32. By operating the sub-converter 34, power is supplied from the inlet 25 to the low voltage battery 30.

  When the control system is activated by a switch operation or the like, power is supplied from the high voltage system 13 to the low voltage system 32 through the main converter 33 (first supply mode). Further, at the time of external charging in which the external power supply 20 is connected to the inlet 25, power is supplied from the external charging system 21 to the low voltage system 32 via the sub converter 34 (second supply mode). That is, when the external power supply 20 is not connected to the inlet 25, the first supply mode for operating the main converter 33 is executed, while when the external power supply 20 is connected to the inlet 25, the sub converter A second delivery mode of operating 34 is performed. Thus, by supplying power to the low voltage system 32 from the sub converter 34 at the time of external charging, power can be supplied to the low voltage system 32 without passing through the high voltage battery 11, and energy efficiency at the time of external charging Can be improved.

  The main converter 33 and the sub converter 34 are so-called DC-DC converters configured by switching elements, reactors, and the like, and have a function of stepping down DC power and supplying it to the low voltage system 32. Further, the charger 23 and the sub converter 34 are accommodated in one case 40, and the charger 23 and the sub converter 34 constitute one on-vehicle charging unit 41. As described above, by incorporating the charger 23 and the sub-converter 34 into one case 40, it is possible to achieve sharing of a cooling system etc., and it is possible to reduce the number of parts and to reduce the cost.

  The vehicle power supply device 10 includes a controller 42 that controls the charger 23, the main converter 33, the sub converter 34, and the like. As described above, at the time of external charging in which the external power supply 20 is connected to the inlet 25, the sub-converter 34 is operated to execute the second supply mode for supplying power to the low voltage system 32. That is, the controller 42 not only controls the charger 23 to charge the high voltage battery 11, but also controls the sub-converter 34 to stabilize the power supply voltage applied to the vehicle load 31 such as the controller 42. Incidentally, external charging is often continued for a long time, and operating the sub-converter 34 for a long time has been a factor causing an excessive temperature rise of the sub-converter 34.

  As described above, when the temperature of the subconverter 34 rises excessively, it is necessary to stop the subconverter 34 from the viewpoint of protecting the internal elements. In this case, since the power supply to the low voltage system 32 is cut off, there is a possibility that the power supply voltage of the controller 42 or the like may be reduced as the low voltage battery 30 is discharged. There is a risk of being Furthermore, in the illustrated vehicle power supply device 10, since both the charger 23 and the sub converter 34 are incorporated into the on-vehicle charging unit 41, the heat of the sub converter 34 causes the temperature of the charger 23 to rise. There is a risk. Such temperature rise of the charger 23 is a factor that limits the function of the charger 23, and is a factor that limits or stops external charging.

  Therefore, in order to maintain the power supply to the low voltage system 32 during external charging, the controller 42 executes mode switching control to switch the power supply path of the low voltage system 32 based on the outside air temperature or the like. That is, the controller 42 operates the main converter 33 to supply power to the low voltage system 32 based on the outside air temperature or the like, and operates the sub converter 34 to supply power to the low voltage system 32. Mode switching control to switch between the second supply mode and the second supply mode. As described above, the controller 42 functioning as a mode control unit includes the outside air temperature sensor 43 for detecting the outside air temperature, the charger temperature sensor 44 for detecting the temperature of the charger 23, and the main temperature sensor for detecting the temperature of the main converter 33. 45 and a sub temperature sensor 46 for detecting the temperature of the sub converter 34 are connected. The controller 42 is configured by a microcomputer including a CPU, a ROM, a RAM, and the like, a drive circuit unit that generates a control current, and the like.

[Mode switching control]
Hereinafter, mode switching control executed by the controller 42 will be described. The mode switching control is executed along with the connection of the external power supply 20 to the inlet 25. FIG. 2 is a flowchart showing an example of an execution procedure of mode switching control. In FIG. 2, the temperature of the main converter 33 is described as “main temperature”, the temperature of the sub converter 34 is described as “sub temperature”, and the temperature of the charger 23 is described as “charger temperature”. Further, in FIG. 2, “main” means the main converter 33, and “sub” means the sub converter 34.

  As shown in FIG. 2, in step S10, it is determined whether the outside air temperature is equal to or higher than a predetermined temperature (first threshold) T1. If it is determined in step S10 that the outside air temperature exceeds the predetermined temperature T1 (for example, 40 ° C.), that is, if the ambient temperature of the vehicular power supply device 10 is estimated to be high, the process proceeds to step S11, and the main A first supply mode for operating converter 33 is performed. As described above, when the first supply mode is executed, the process proceeds to step S12, and it is determined whether the temperature of the main converter 33 is lower than or equal to a predetermined temperature (second threshold) T2. If it is determined in step S12 that the temperature of main converter 33 is lower than predetermined temperature T2, then the process proceeds to step S13 since the temperature of main converter 33 is within the normal range. The continuation of the supply mode is determined. On the other hand, if it is determined in step S12 that the temperature of the main converter 33 exceeds the predetermined temperature T2, the temperature of the main converter 33 exceeds the normal range, so the process proceeds to step S14 and the second supply mode is started. A switch to supply mode is determined.

  On the other hand, if it is determined in step S10 that the outside air temperature is lower than the predetermined temperature T1, that is, it is estimated that the ambient temperature of the vehicular power supply device 10 is normal temperature, the process proceeds to step S15 and the subconverter 34 A second feed mode of operation is performed. As described above, when the second supply mode is executed, the process proceeds to step S16, and it is determined whether the temperature of the sub converter 34 is lower than or equal to a predetermined temperature (third threshold) T3. If it is determined in step S16 that the temperature of subconverter 34 is lower than predetermined temperature T3, the process proceeds to step S17, and it is determined whether the temperature of charger 23 is lower than or equal to predetermined temperature (fourth threshold) T4. Be done. Then, if it is determined in step S17 that the temperature of charger 23 falls below predetermined temperature T4, since the temperatures of sub converter 34 and charger 23 are within the normal range, the process proceeds to step S18 and the sub converter The continuation of the second supply mode using 34 is determined. On the other hand, if it is determined in step S16 that the temperature of sub converter 34 exceeds predetermined temperature T3 or if it is determined in step S17 that the temperature of charger 23 exceeds predetermined temperature T4, sub converter 34 Alternatively, since the temperature of the charger 23 exceeds the normal range, the process proceeds to step S19, and it is determined to switch from the second supply mode to the first supply mode.

  Even if the first supply mode or the second supply mode is executed after steps S13, S14, S18, and S19, the process proceeds to step S10 again, and it is determined whether the outside air temperature is equal to or higher than the predetermined temperature T1. Is determined. That is, even if the first supply mode is executed after steps S13 and S19, if it is determined in step S10 that the outside air temperature is lower than the predetermined temperature T1, the process proceeds to step S15. The first supply mode is switched to the second supply mode. Similarly, even if the second supply mode is executed after steps S14 and S18, if it is determined in step S10 that the outside air temperature is equal to or higher than the predetermined temperature T1, the process proceeds to step S11 , And the second supply mode is switched to the first supply mode.

  As described above, when the outside air temperature exceeds the predetermined temperature T1, that is, when the ambient temperature of the in-vehicle charging unit 41 is high, the first supply mode for operating the main converter 33 is executed. Here, FIG. 3 is an explanatory view showing a power supply situation when the first supply mode is executed during the external charging. The solid arrows shown in FIG. 3 indicate the power supply status. As shown in FIG. 3, when the ambient temperature of the in-vehicle charging unit 41 is high, power is supplied from the main converter 33 to the low voltage system 32 by executing the first supply mode. As a result, while the power supply to the low voltage system 32 is maintained, the sub-converter 34 can be stopped to stop the heat generation, and the temperature rise of the in-vehicle charging unit 41, that is, the charger 23 can be suppressed. Thus, since the output restriction of the charger 23 can be avoided by suppressing the temperature rise of the charger 23, the charging of the high voltage battery 11 can be continued, and the charging time of the high voltage battery 11 can be maintained. Can be shortened. As a result, the convenience of the user can be improved, and the merchantability of the electric vehicle can be improved.

  On the other hand, when the outside air temperature is lower than the predetermined temperature T1, that is, when the ambient temperature of the on-vehicle charging unit 41 is low, the second supply mode for operating the sub-converter 34 is executed. Here, FIG. 4 is an explanatory view showing a power supply situation when the second supply mode is performed during the external charging. The black arrows shown in FIG. 4 are arrows indicating the power supply status. As shown in FIG. 4, when the ambient temperature of the in-vehicle charging unit 41 is low, power is supplied from the sub-converter 34 to the low voltage system 32 by executing the second supply mode. As described above, when the ambient temperature of the in-vehicle charging unit 41 is low, that is, when the excessive temperature rise of the charger 23 hardly occurs, the sub converter 34 is actively operated by executing the second supply mode. I am doing it. Thereby, power can be supplied from the external charging system 21 to the low voltage system 32 without passing through the high voltage battery 11, and energy efficiency at the time of external charging can be improved.

  When the temperature of the main converter 33 exceeds the normal range under the state where the first supply mode is being executed, the first supply mode is switched to the second supply mode. As a result, since the main converter 33 can be stopped, the main converter 33 can be protected while maintaining the power supply to the low voltage system 32 and continuing the external charging. When the temperature of the sub-converter 34 exceeds the normal range under the state where the second supply mode is being executed, the second supply mode is switched to the first supply mode. As a result, the sub-converter 34 can be stopped, so that the sub-converter 34 can be protected while maintaining the power supply to the low voltage system 32 and continuing the external charging. In addition, when the temperature of the charger 23 exceeds the normal range under the state where the second supply mode is being executed, the second supply mode is switched to the first supply mode. Thereby, the heat generation of the sub converter 34 can be stopped, and the temperature rise of the in-vehicle charging unit 41, that is, the charger 23 can be suppressed. That is, since the output restriction of the charger 23 due to the temperature rise can be suppressed, the charging of the high voltage battery 11 can be continued, and the significant extension of the charging time can be avoided.

Other Embodiments
In the example shown in FIG. 1, the vehicle power supply device 10 includes the charger 23, but the present invention is not limited to this, and the charger 23 can be connected to the vehicle power supply device 10 by using a charging facility outside the vehicle. You may omit it. Here, FIG. 5 is a schematic view showing a configuration of a vehicle power supply device 50 according to another embodiment of the present invention. In addition, in FIG. 5, about the components similar to the components shown in FIG. 1, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  As shown in FIG. 5, the vehicle power supply device 50 is provided with an external charging system 51 for supplying power from the external power supply 20 to the high voltage battery 11. The external charging system 51 energizes the high voltage battery 11. It has an inlet 25 connected via a line 52. When charging the high voltage battery 11 using the external power supply 20, the connector 27 of the charging cable 26 extending from the charging facility 53 outside the vehicle is connected to the inlet 25. By connecting the charging cable 26 to the inlet 25 in this manner, the external power supply 20 is connected to the inlet 25 via the charging facility 53.

  As described above, even the vehicle power supply device 50 not having the charger 23 performs the mode switching control based on the outside air temperature or the like as shown in the flowchart of FIG. You can get the effect. That is, when the outside air temperature or the temperature of the sub converter 34 is low, the second supply mode for operating the sub converter 34 is executed. Thus, power can be supplied from the external charging system 51 to the low voltage system 32 without passing through the high voltage battery 11, and energy efficiency at the time of external charging can be improved. On the other hand, when the outside air temperature or the temperature of the sub converter 34 is high, the first supply mode for operating the main converter 33 is executed. Thereby, even if the temperature of sub converter 34 rises excessively during external charging, power supply to low voltage system 32 can be continued using main converter 33, so the controller can be used during external charging. The power supply voltage such as 42 can be stabilized. As a result, external charging can be properly continued, so charging of the high voltage battery 11 can be continued, and extension of the charging time can be suppressed.

  It is needless to say that the present invention is not limited to the above embodiment, and various modifications can be made without departing from the scope of the invention. The illustrated electric vehicle is an electric vehicle equipped with only the motor generator 12 as a motive power source, but is not limited to this, and may be a hybrid type electric vehicle equipped with a motor generator and an engine as a motive power source.

  In the above description, the mode switching control is performed based on the outside air temperature, the temperature of the main converter 33, the temperature of the sub converter 34, and the temperature of the charger 23. However, the present invention is not limited thereto. For example, the mode switching control may be performed based on at least one of the outside air temperature, the temperature of the main converter 33, the temperature of the sub converter 34, and the temperature of the charger 23. Further, the present invention is not limited to the above-described temperatures, and mode switching control may be performed based on temperatures such as a cabin temperature and a battery temperature.

  Further, a predetermined temperature T1 to be compared with the outside air temperature, a predetermined temperature T2 to be compared with the temperature of the main converter 33, a predetermined temperature T3 to be compared with the temperature of the subconverter 34, and a predetermined temperature to be compared with the temperature of the charger 23. Each temperature of T4 is a temperature suitably set based on the temperature etc. which protection control intervenes with respect to each apparatus. The predetermined temperatures T1 to T4 are temperatures appropriately set according to the specifications of the respective devices, but they may be the same temperature or different from each other.

  In the above description, the batteries 11 and 30 are used as the first and second power storage units, but the present invention is not limited to this. A capacitor may be used as the first and second power storage units. Moreover, although the inlet 25 is provided in the electric vehicle in the example to show in figure, it is not restricted to this, You may provide a charging cable in an electric vehicle. In this case, the charging cable on the electric vehicle side functions as a power supply connection. Although charger 23 and sub-converter 34 are incorporated in one case 40 in the example shown in FIG. 1, the present invention is not limited to this. Even if charger 23 and sub-converter 34 are separately provided. good.

10 Vehicle Power Supply Device 11 High Voltage Battery (First Power Storage Body)
20 external power supply 23 charger 25 inlet (power supply connection)
30 Low Voltage Battery (Second Battery)
33 Main converter (1st power converter)
34 Sub converter (2nd power converter)
40 Case 42 Controller (Mode Controller)
50 Vehicle Power Supply T1 Predetermined Temperature (First Threshold)
T2 predetermined temperature (second threshold)
T3 predetermined temperature (third threshold)
T4 predetermined temperature (fourth threshold)

Claims (6)

A power supply apparatus for a vehicle, comprising: a first power storage unit and a second power storage unit having a voltage lower than that of the first power storage unit,
A power supply connection unit to which the external power supply is connected when the first power storage body is charged using the external power supply;
A first power converter provided between the first power storage unit and the second power storage unit, for supplying power from the first power storage unit to the second power storage unit;
A second power converter provided between the power supply connection unit and the second power storage unit, which supplies power from the power supply connection unit to the second power storage unit;
A first supply mode for supplying power to the second storage body via the first power converter during external charging in which the external power supply is connected to the power supply connection unit; and via the second power converter A mode control unit that switches between a second supply mode of supplying power to the second storage body;
Have
The said mode control part switches the said 1st supply mode and a said 2nd supply mode based on temperature, The power supply device for vehicles. In the vehicle power supply device according to claim 1,
The vehicle mode control unit executes the first supply mode when the outside air temperature exceeds a first threshold, and executes the second supply mode when the outside air temperature falls below the first threshold. Power supply. In the vehicle power supply device according to claim 1 or 2,
The mode control unit is configured to execute the first supply mode to the second supply mode when the temperature of the first power converter exceeds a second threshold while the first supply mode is being executed. Switch to the power supply for vehicles. The power supply device for a vehicle according to any one of claims 1 to 3.
The mode control unit is configured to execute the first supply mode from the second supply mode when the temperature of the second power converter exceeds a third threshold under a state in which the second supply mode is being executed. Switch to the power supply for vehicles. The power supply device for a vehicle according to any one of claims 1 to 4.
A charger provided between the power supply connection portion and the first power storage body, for supplying power from the power supply connection portion to the first power storage body;
The vehicle power supply device, wherein both the charger and the second power converter are housed in one case. In the vehicle power supply device according to claim 5,
The mode control unit switches from the second supply mode to the first supply mode when the temperature of the charger exceeds a fourth threshold under a state in which the second supply mode is being executed. Power supply for vehicles.

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