JP2008109749A - Power supply apparatus for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power supply apparatus for a vehicle, which is high in efficiency, at low cost. <P>SOLUTION: The apparatus controls switches 21-32 for switching the electrical connection states of battery modules 11-15 between a serial connection and parallel connection, and thereby power is supplied to motor generators 2, 5 at different voltages V100, V200 from power lines 101, 102. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a power supply device for a vehicle.

  In a motor generator mounted on a vehicle, when the load is low, the loss to the inverter can be reduced by setting the voltage to the inverter low, and when the load is high By setting the voltage to the inverter to a high voltage, the back electromotive voltage can be suppressed and a current can flow.

  However, a motor generator is disposed on each of the front and rear wheels of the vehicle. For example, the front wheels are driven by the driving force generated by the engine and the driving force generated by the motor generator, and the rear wheels are driven by the driving force generated by the motor generator. In the case of driving only the motor generator, the motor generator for driving the front wheels and the motor generator for driving the rear wheels may have different rotation regions. That is, the voltage applied to the motor generator may be different.

Therefore, Patent Document 1 discloses a configuration in which a DC / DC converter is connected to each of motor generators arranged on the front wheels and the rear wheels to control voltages applied to the motor generators.
JP 2004-242371 A

  However, in the above invention, when the DC / DC converter is arranged, it is necessary to increase the breakdown voltage of the elements constituting the DC / DC converter, and there are problems such as an increase in cost, a reduction in efficiency due to switching loss, and on-loss.

  The present invention was devised to solve such problems, and it supplies power to each motor generator without using a DC / DC converter, thereby reducing costs, reducing losses, and efficiently generating motor generators. The purpose is to supply electric power to.

  In the present invention, a plurality of power supplies for supplying power to a plurality of power consuming means, a circuit for connecting the plurality of power supplies in series or in parallel, and a circuit, the electrical connection state between the plurality of power supplies, A plurality of switching means for switching to serial connection or parallel connection, a power extraction circuit for connecting the circuit and the power consumption means, and switching between serial connection or parallel connection between the power sources according to the operating state of the power consumption means, Control means for controlling the voltages of the plurality of power extraction circuits.

  According to the present invention, the power consumption means and the circuit are connected by switching the electrical connection state between the plurality of power supply devices by the switching means provided in the circuit for connecting the plurality of power supply devices in series or in parallel. It is possible to control the voltage of the power take-out circuit, and to control the voltage required by the power consuming means. As a result, for example, power can be supplied to the power consuming means without using a DC / DC converter, cost can be reduced, and power can be efficiently supplied to the motor generator.

  A vehicle drive system according to a first embodiment of the present invention will be described with reference to the schematic configuration diagram of FIG.

  The vehicle drive system of this embodiment includes an engine 1, a motor generator (second motor generator) 2 that is the same as or independent of the engine 1, and the rotational speed of the output shaft of the engine 1 or the motor generator 2. , A transmission 3 that changes the radius of rotation, a front wheel 4 that is driven by torque transmitted from the transmission 3, a motor generator (first motor generator) 5 that independently serves as power for the vehicle, and transmission from the motor generator 5. The rear wheel 6 driven by the generated torque, the power supply device 7 for supplying power to the motor generators 2 and 5, the inverter 8 disposed between the power supply device 7 and the motor generator 2, and the power supply device 7 , An inverter 9 disposed between the motor generator 5, the power supply device 7, and the motor generators 2, 5 Includes a breaker 10 to an electrical connection selectively switched, the.

  The motor generator 2 rotates the output shaft by the electric power supplied from the power supply device 7 via the inverter 8 and drives the front wheels 4 via the transmission 3. Further, during braking of the vehicle, power is generated by the rotation transmitted through the front wheels 4 and the transmission 3, and power is supplied to the power supply device 7 through the inverter 8.

  The inverter 8 converts DC power supplied from the power supply device 7 into AC power and supplies it to the motor generator 2, and converts AC power generated by the motor generator 2 into DC power and supplies power to the power supply device 7. Supply.

  The motor generator 5 drives the rear wheels 6 with the electric power supplied from the power supply device 7 via the inverter 9. When the vehicle is braked, power is generated by the rotation transmitted through the rear wheel 6, and power is supplied to the power supply device 7 through the inverter 9.

  The inverter 9 converts DC power supplied from the power supply device 7 into AC power and supplies it to the motor generator 5, and converts AC power generated by the motor generator 5 into DC power and supplies power to the power supply device 7. Supply. The inverters 8 and 9 have a common negative terminal, and the positive terminal of the inverter 8 and the positive terminal of the inverter 9 can be connected to the power supply device 7, respectively.

  The circuit breaker 10 is a mechanical relay, for example, and selectively switches the electrical connection state between the power supply device 7 and the inverter 8 and between the power supply device 7 and the inverter 9.

  The power supply device 7 will be described in detail with reference to FIG.

  The power supply device 7 takes out electric power from the battery pack 100, the electric power line (second electric power extraction circuit) 101 that takes out electric power from the battery pack 100 and supplies electric power to the motor generator 2, and takes out electric power from the battery pack 100, 5 includes a power line (first power extraction circuit) 102 that supplies power to 5 and a controller (control means) 200 that switches ON / OFF of switches 21 to 32 described later.

  The battery pack 100 is provided in a plurality of battery modules (power supplies) 11, 12, 13, 14, 15, a circuit 33 that connects the battery modules 11, 12, 13, 14, 15 in series or in parallel, and the circuit 33. , Switches (switching means) 21 to 32 capable of switching the electrical connection state of the battery modules 11, 12, 13, 14, and 15 in series or in parallel.

  The battery modules 11, 12, 13, 14, and 15 are power storage means such as nickel metal hydride batteries and capacitors.

  The switches 21 to 32 are semiconductor switches, and the switches 21, 22, 24, 25, 27, 28, 30, and 31 are switches for connecting the battery modules 11 to 15 in parallel, and each switch is turned on. Thus, the battery modules 11 to 15 are connected in parallel. Moreover, the switches 23, 26, 29, and 32 are switches for connecting the battery modules 11 to 15 in series, and the battery modules 11 to 15 are connected in series when each switch is turned on. That is, the connection state between the battery modules 11 to 15 can be switched between parallel connection and series connection by appropriately switching ON / OFF of the switches 21 to 32.

  The power line 101 includes a power adjustment switch (second power adjustment switch) 40, a diode (second diode) 42, and a reactor (second reactor) 44. In the power line 101, the power adjustment switch 40 and the reactor 44 are arranged in series between the battery pack 100 and the circuit breaker 10, and the diode 42 is arranged in parallel between the battery pack 100 and the circuit breaker 10. . The diode 42 is disposed between the power adjustment switch 40 and the reactor 44. The positive terminal (second positive terminal) 101a of the power line 101 is connected between the battery module 13 and the battery module 14 and can extract power from the battery modules 11-15. The power line 101 supplies power from the battery pack 100 to the motor generator 2 via the circuit breaker 10 and the inverter 8, and supplies power to the battery pack 100 by a part of the power generated by the motor generator 2 during braking. Then, the battery modules 11 to 15 can be charged. Hereinafter, the voltage of the power line 101 is referred to as voltage V100.

  The power line 102 includes a power adjustment switch (first power adjustment switch) 41, a diode (first diode) 43, and a reactor (first reactor) 45. In the power line 102, the power adjustment switch 41 and the reactor 45 are arranged in series between the battery pack 100 and the circuit breaker 10, and the diode 43 is arranged in parallel between the battery pack 100 and the circuit breaker 10. . The diode 43 is disposed between the power adjustment switch 41 and the reactor 45. The positive terminal (first positive terminal) 102a of the power line 102 is connected to the positive side of the battery module 11 and can extract power from the battery modules 11-15. Further, the battery modules 11 to 15 can be charged by supplying electric power to the battery pack 100 by a part of the electric power generated by the motor generator 5 during braking. Hereinafter, the voltage of the power line 102 is referred to as a voltage V200.

  With the above configuration, electric power is supplied from the battery pack 100 to the motor generators 2 and 5 using the electric power lines 101 and 102, and the battery modules 11 to 15 are charged with a part of the electric power generated by the motor generators 2 and 5. can do.

  Here, the relationship between the ON / OFF states of the switches 21 to 32 and the voltages V100 and V200 is shown in FIG. In FIG. 3, the voltage of each battery module is the same voltage, and is assumed to be voltage V <b> 1. By switching ON / OFF of the switches 21 to 32 in accordance with the operation state (load) of the motor generators 2 and 5, the connection states of the battery modules 11 to 15 can be switched in series and parallel. Note that there is a series-parallel connection that realizes the same voltage state at the voltages V100 and V200 by switching the switches 21 to 32. Battery modules that have been connected in series to extract power have lower SOC (state of charge) of the battery modules than battery modules that have been connected in parallel to extract power, resulting in variations in SOC between battery modules. However, by appropriately switching ON / OFF of the switches 21 to 32, it is possible to reduce the SOC variation between the battery modules.

  Here, a current flow in a certain series-parallel connection state will be described with reference to FIGS.

  FIG. 4 shows a current flow when the switches 21, 22, 26, 27, 28, 30 and 31 are ON and the switches 23, 24, 25, 29 and 32 are OFF. That is, the battery modules 11 and 12 are connected in parallel, the battery modules 13, 14, and 15 are connected in parallel, and the battery modules 11 and 12 and the battery modules 13, 14, and 15 are connected in series. In this connection state, the voltage V100 is the voltage V1, and the voltage V200 is the voltage 2V1, which is twice the voltage V100.

  FIG. 5 shows a current flow when the switches 23, 26, 27, 28, and 32 are ON and the switches 21, 22, 24, 25, 29, 30, and 31 are OFF. That is, the battery modules 13 and 14 are connected in parallel, and the battery module 11, the battery module 12, the battery modules 13 and 14, and the battery module 15 are connected in series. In this connection state, the voltage V100 becomes the voltage 2V1, and the voltage V200 becomes the voltage 4V1.

  Next, boost control in the power running state of this embodiment will be described with reference to FIG. In FIG. 6, a power supply device 7, a smoothing capacitor 50 provided inside the inverter 8, and a smoothing capacitor 51 provided inside the inverter 9 are shown.

  When changing the voltage V100 and voltage V200 supplied from the battery pack 100 by switching ON / OFF of the switches 21 to 32, the power adjustment switches 40 and 41 are turned OFF to supply power from the battery pack 100. To stop.

  Then, the switches 21 to 32 are switched ON / OFF inside the battery pack 100 to switch the connection state of the battery modules 11 to 15 to a desired connection state. For example, when the current voltage V100 is the voltage V1 and the voltage V100 is increased, the voltage V100 can be set to the voltage 2V1 by connecting the battery module 14 and the battery module 15 in series.

  Thereafter, when the power adjustment switches 40 and 41 are turned ON, a current flows toward the smoothing capacitors 50 and 51. The electric power lines 101 and 102 are respectively provided with reactors 44 and 45, and the amount of change in current is suppressed by the reactors 44 and 45 (FIG. 6A). When the power adjustment switches 40 and 41 are turned OFF, the current from the battery pack 100 does not flow toward the smoothing capacitors 50 and 51, but the current flows from the reactors 44 and 45 toward the smoothing capacitors 50 and 51 ( FIG. 6 (b)).

  As described above, the power adjustment switches 40 and 41 are turned off, and the switches 21 to 32 are turned on / off, and then the power adjustment switches 40 and 41 are switched to increase the voltage to a desired voltage. .

  When a DC / DC converter is used, it is necessary to hold the voltage by switching operation even after the boosting is finished. In this embodiment, however, the switching operation needs to be performed once the boosting is finished. Therefore, the switching loss caused by the switching operation can be suppressed.

  Also, when boosting with a DC / DC converter, if the voltage on the input side to the DC / DC converter is set to a low value, for example, V1, in accordance with the low power supply, In this embodiment, the voltages V100 and V200 can be changed by switching ON / OFF of the switches 21 to 32. Therefore, in this embodiment, the switches 21 to 32 are changed. It is possible to suppress an increase in the current flowing through and the like, and it is possible to suppress an on loss due to the increase in the current. In addition, the withstand voltages of the power adjustment switches 40 and 41 and the switches 21 to 32 can be lowered, and the cost can be reduced. In this embodiment, the diode 43 has a higher breakdown voltage than the diode 42, and the diode 42 has a higher breakdown voltage than the power adjustment switches 40 and 41 and the switches 21 to 32. That is, a relatively low withstand voltage element can be used, and the cost can be reduced.

  Further, for example, by increasing the voltage V200 stepwise, it is possible to prevent the current flowing through the switches 21 to 32 from rapidly increasing, and the withstand voltage of the switches 21 to 32 can be lowered, thereby reducing the cost. be able to.

  Changes in the target voltage commands and induced voltages of the voltages V100 and V200 in the step-up control in the power running state of this embodiment will be described with reference to FIG.

  When the acceleration is large, the transmission 3 maintains the current gear ratio as much as possible to improve the acceleration performance. When acceleration is large, voltage V100 is changed from V1 to 2V1, and the induced voltage of motor generator 2 increases. Further, since the vehicle speed increases, the voltage V200 applied to the motor generator 5 is changed stepwise from V1 to 5V1, and the induced voltage of the motor generator 5 increases.

  When the acceleration is small, the rotational speed of the engine 1 is kept as small as possible in order to improve fuel efficiency, and the transmission 3 shifts to the High side at a relatively early stage. When the acceleration is small, the voltage V100 remains V1, and the induced voltage of the motor generator 2 does not become higher than when the acceleration is large. Further, when the vehicle speed increases, voltage V200 is changed stepwise from V1 to V3, and the induced voltage of motor generator 5 increases.

  As described above, the voltages V100 and V200 are controlled according to the electric power required for the motor generators 2 and 5, that is, the ON / OFF switching of the switches 21 to 32 is controlled. Control the induced voltage. In this embodiment, the maximum voltage applied to the motor generator 2 is 2V1, but it is also possible to increase the output of the motor generator 2 by weakening the voltage of 2V1 and performing the field.

  In addition, even when the output of the motor generator 2 is regulated by the limitation of the voltage applied to the motor generator 2, power is preferentially distributed to the motor generator 5 to which a higher voltage can be applied, thereby driving the vehicle. You can maintain power.

  The braking force (regeneration amount) distribution between the front wheels and the rear wheels during braking is distributed according to the weight distribution before and after the vehicle, the position of the center of gravity of the vehicle, and the like. In the cooperative regenerative brake that divides the braking force distributed to the front wheels and rear wheels into the braking force generated by the motor generator power generation torque and the braking force generated by the mechanical brake, the braking force generated by the motor generator power generation torque and the mechanical brake The braking force is distributed to and the braking force.

  In this embodiment, the motor generators 2 and 5 generate electric power during braking to charge the battery modules 11 to 15 of the battery pack 100.

  The braking force distributed by the front wheel 4 and the rear wheel 6 at the time of braking is set in advance, and each braking force on the front wheel 4 and the rear wheel 6 is distributed by the motor generators 2 and 5 or the mechanical brake.

  Further, in the battery modules 11 to 15 of the battery pack 100, since the discharge amount of the battery modules that are connected in series at the time of discharging is larger than the discharge amount of the battery modules that are connected in parallel, the battery that is connected in series The module SOC is relatively low. Therefore, in this embodiment, at the time of braking, power is preferentially supplied to the battery modules that are connected in series, and the battery module having a relatively low SOC is charged. The battery modules 11 to 15 may be charged from the motor generators 2 and 5 by detecting the SOC of the battery modules 11 to 15 and connecting battery modules having a low SOC in series. Thereby, the variation in SOC of the battery modules 11-15 can be reduced.

  Changes in the target voltage commands of the voltages V100 and V200 in the regenerative state during braking and the braking force on the front and rear wheels will be described with reference to the time chart of FIG. It is assumed that voltage V200 is 3V1 and voltage V100 is 2V1 when braking is started.

  When braking is started at time t0, electric power is supplied from the motor generator 2 via the inverter 8 and from the motor generator 5 via the inverter 9 to the battery modules 11-15 of the battery pack 100. 15 is charged.

  At time t1, when the braking force of the rear wheel 6 becomes a predetermined braking force, the braking force (regenerative power) of the motor generator 5 is reduced, that is, the power generation amount of the motor generator 5 is temporarily reduced. In addition, the power generation amount reduced by the motor generator 5 is generated by the motor generator 2, whereby the battery modules 11 to 15 can be charged, and the fuel efficiency can be improved.

  At time t2, the switches 21 to 32 are switched ON / OFF so that the voltage V200 is changed from 3V1 to 2V1. At this time, since the voltage of the smoothing capacitor 51 of the inverter 9 is 3V1, a current flows from the smoothing capacitor 51 to the battery pack 100. However, the amount of change in the current is suppressed by the reactor 45. However, in such a case, the current may become relatively large due to the current from the smoothing capacitor 51 and the current generated by the power generation of the motor generator 5. By temporarily reducing the amount, a large current is prevented from flowing.

  When the voltage of the smoothing capacitor 51 becomes sufficiently low at time t3, the power generation amount of the motor generator 5 is increased. Further, the power generation amount of the motor generator 2 is reduced.

  Thus, when the rotational speed of the motor generators 2 and 5 is reduced during braking and the voltage V100 or the voltage V200 is reduced, a large current is generated by temporarily reducing the power generation amount of the motor generator that reduces the voltage. It can be prevented from flowing.

  The effect of 1st Embodiment of this invention is demonstrated.

  In this embodiment, when the voltages supplied to the motor generators 2 and 5 are different, the voltage V100 applied to the motor generator 2 via the inverter 8 by switching the switches 21 to 32 ON / OFF, and the motor generator 5 The voltage V200 applied via the inverter 9 can be controlled. Thus, for example, without using a DC / DC converter, the voltages V100 and V200 can be applied from the battery pack 100 to the motor generators 2 and 5 via the inverters 8 and 9, respectively, and the cost can be reduced.

  In addition, since switching is not required after boosting, switching loss due to switching of switches can be suppressed. In addition, the current flowing through the switches 21 to 32 can be reduced, and the on-loss can be reduced. Further, for example, when the voltage V200 is increased, the voltage can be increased stepwise, and a large current can be prevented from flowing through the inverters 8 and 9. Therefore, an element with a low withstand voltage can be used, and cost can be reduced.

  When switching ON / OFF of the switches 21 to 32, the power adjustment switches 41 and 42 are turned OFF, and then the switches 21 to 32 are switched ON / OFF, thereby preventing a large current from flowing through the inverters 8 and 9. be able to. Therefore, an element with a low withstand voltage can be used, and cost can be reduced.

  During braking, power is preferentially supplied to the battery module having a low SOC, and charging is performed, so that variations in the SOC of the battery modules 11 to 15 can be reduced.

  During braking, when the switches 21 to 32 are switched ON / OFF and the voltage V100 or V200 is stepped down, the power generation amount of the motor generator 2 or motor generator 5 to which the stepped down voltage V100 or V200 is applied is temporarily set. Make it smaller. When the voltage V100 or V200 is stepped down, a large current may flow due to the current from the smoothing capacitors 50 and 51 and the current generated by the motor generators 2 and 5; Alternatively, it is possible to suppress a large current from flowing through the battery pack 100 by temporarily reducing the amount of power generated by the motor generator 2 or the motor generator 5 to which V200 is applied. Further, when the power generation amount of the motor generator 2 or the motor generator 5 is temporarily reduced, the power generation amount of the other motor generator 2 or the motor generator 5 is temporarily increased, whereby the battery modules 11 to 15 are Can be charged, and fuel consumption can be improved.

  Next, a second embodiment of the present invention will be described with reference to FIG. This embodiment is an electric vehicle in which the front wheels 4 are driven by the torque generated by the motor generator 60 and the rear wheels 6 are driven by the torque generated by the motor generator 5.

  In this embodiment, the voltage characteristics to be applied to the motor generators 5 and 60 are set according to vehicle weight distribution and the like. For example, since the rear wheel load increases during acceleration, the induced voltage of motor generator 5 becomes higher than the induced voltage of motor generator 60.

  The effect of 2nd Embodiment of this invention is demonstrated.

  Also in the electric vehicle, the voltage applied to the motor generators 5 and 60 can be controlled according to the driving state, and the same effect as in the first embodiment can be obtained.

  Next, a third embodiment of the present invention will be described with reference to FIG. This embodiment includes a motor generator 63 that divides the driving force of the engine 61 by the planetary gear 62 and generates electric power by a part of the driving force of the engine 1, and a motor generator 65 that applies driving force to the wheels 64.

  In this embodiment, different voltages are applied to the motor generator 63 and the motor generator 65 from the power supply device 7. For example, when a large driving force is required at a low vehicle speed, the motor generator 63 has a high rotational speed, and the induced voltage of the motor generator 63 increases. In addition, since the driving force is assisted by the motor generator 65 in medium acceleration or the like, the induced voltage of the motor generators 63 and 65 becomes high.

  The effect of the third embodiment of the present invention will be described.

  In this embodiment, different voltages can be applied to the motor generator 63 and the motor generator 65 from the power supply device 7, and the same effect as in the first embodiment can be obtained.

  Next, a fourth embodiment of the present invention will be described with reference to FIG. In this embodiment, the positive terminal of the power supply line 103 that supplies power to the motor generator 2 is between the battery module 11 and the battery module 12, between the battery module 12 and the battery module 13, and The battery module 14 is connected to the battery module 14. The voltage V100 of the motor generator 2 can be changed by switching ON / OFF of the bidirectional switches 70 to 72 and ON / OFF of the switches 21 to 32.

  The effect of 4th Embodiment of this invention is demonstrated.

  In this embodiment, the voltage V100 of the motor generator 2 can be switched by switching ON / OFF of the bidirectional switches 70 to 72.

  It goes without saying that the present invention is not limited to the above-described embodiments, and includes various modifications and improvements that can be made within the scope of the technical idea.

1 is a schematic configuration diagram of a vehicle drive system according to a first embodiment of the present invention. 1 is a circuit diagram of a power supply device according to a first embodiment of the present invention. It is a map which shows the relationship between ON / OFF of the switch of 1st Embodiment of this invention, and voltage V100, V200. (A) It is a figure which shows the ON / OFF state of a certain switch of 1st Embodiment of this invention, and the (b) electric current flow. (A) It is a figure which shows the ON / OFF state of a certain switch of 1st Embodiment of this invention, and the (b) electric current flow. It is a figure which shows the flow of the electric current in the power running state of 1st Embodiment of this invention, (a) It is a figure which shows the flow of the electric current from a battery pack. (B) It is a figure which shows the flow of the electric current from a reactor. It is a figure which shows the time change of the target voltage command of the voltages V100 and V200 of the power running state of 1st Embodiment of this invention, and an induced voltage. It is a figure which shows the time change of the target voltage command of the voltage V100 of the regeneration state of 1st Embodiment of this invention, and the braking force of the front wheel side and the rear wheel side. It is a schematic block diagram of the vehicle drive system of 2nd Embodiment of this invention. It is a schematic block diagram of the vehicle drive system of 3rd Embodiment of this invention. It is a circuit diagram of the electric power supply apparatus of 4th Embodiment of this invention.

Explanation of symbols

2 Motor generator (second motor generator)
4 Front wheel 5 Motor generator (first motor generator)
6 Rear wheel 7 Power supply device 8 Inverter 9 Inverter 11-15 Battery module (power supply)
21-32 switch (switching means)
33 Circuit 40 Power adjustment switch (second power adjustment switch)
41 Power adjustment switch (first power adjustment switch)
42 Diode (second diode)
43 Diode (first diode)
44 reactor (second reactor)
45 reactor (first reactor)
50 Smoothing capacitor 51 Smoothing capacitor 100 Battery pack 101 Power line (second power extraction circuit)
101a Positive terminal (second positive terminal)
102a Positive terminal (first positive terminal)
102 Power line (first power extraction circuit)
200 controller (control means)

Claims (6)

A plurality of power supplies for supplying power to a plurality of power consuming means;
A circuit for connecting the plurality of power supplies in series or in parallel;
A plurality of switching means provided in the circuit, for switching an electrical connection state between the plurality of power sources to a serial connection or a parallel connection;
A power extraction circuit connecting the circuit and the power consumption means;
Control means for controlling the voltages of the plurality of power extraction circuits by switching the series connection or the parallel connection between the power sources in accordance with the operating state of the power consuming means. Feeding device. The power extraction circuit includes:
When all of the plurality of power supplies are connected in series, a negative electrode terminal that is the lowest potential of the plurality of power supplies, a first positive electrode terminal that is the highest potential of the plurality of power supplies, and first power consuming means A first power extraction circuit that electrically connects
When the plurality of power supplies are all connected in series, the negative terminal, the second positive terminal having a lower potential than the first power extraction circuit, and the second power consuming means are electrically connected. The vehicle power supply device according to claim 1, further comprising: a second power extraction circuit that performs the operation. The first power extraction circuit includes:
Between the first positive terminal and the first power consuming means, a first reactor and a first power adjustment switch connected in series to the power source, and a parallel connection to the power source. A first diode;
The second power extraction circuit includes:
Between the second positive terminal and the second power consuming means, a second reactor and a second power adjustment switch connected in series to the power source, and a parallel connection to the power source are connected. A second diode;
The first diode has a higher breakdown voltage than the second diode;
The vehicle power supply device according to claim 2, wherein the second diode has a higher withstand voltage than the first and second power adjustment switches and the switching means.   When the electrical connection state between the plurality of power sources is switched by the switching unit, the electrical connection between the power source and the first power consuming unit is interrupted by the first power adjustment switch; and The electrical connection state between the plurality of power sources by the switching unit is switched after the electrical connection between the power source and the second power consuming unit is interrupted by the second power adjustment switch. The vehicle power supply device according to claim 2 or 3. The plurality of power consuming means are a first motor generator and a second motor generator that generate electric power during braking of the vehicle,
When braking the vehicle, the switching means switches the electrical connection state between the plurality of power sources, and when the voltage of the first power extraction circuit or the second power extraction circuit is lowered,
Temporarily reducing the amount of power generated by the first motor generator or the second motor generator connected to the first power extraction circuit or the second power extraction circuit for reducing the voltage;
The power generation amount of the first motor generator or the second motor generator connected to the first power extraction circuit or the second power extraction circuit that does not decrease the voltage is temporarily increased. The power supply device for a vehicle according to any one of claims 2 to 4.   6. The vehicle power supply device according to claim 5, wherein when the vehicle is braked, the power generation amount of the first motor generator is made larger than the power generation amount of the second motor generator.