JP5726046B2 - Vehicle power supply system - Google Patents

Description

  The present invention relates to a vehicle power supply system capable of improving power supply capability.

  As a conventional vehicle power supply system, a generator that is driven by an engine and supplies power to a battery actively regenerates braking energy by setting the generated voltage higher when the vehicle decelerates than when not decelerated. In some cases, when the vehicle is not decelerated, the fuel consumption is improved by reducing the load on the engine by setting it lower than when decelerating (see, for example, Patent Document 1).

  However, since the above-described vehicle power supply system is configured to charge the battery by directly supplying the generated power of the generator to the battery, if the generated power of the generator is changed greatly, the life of the battery is shortened. It leads to things.

  In order to solve such a problem, the following vehicles that can increase the power generation voltage of the generator and actively regenerate the braking energy of the vehicle while keeping the voltage of each part of the vehicle power supply system appropriate Power supply systems have been proposed. In other words, this vehicle power supply system includes a generator that is driven by an engine to generate AC power, a rectifier that rectifies the AC power into DC power and outputs it to a power generation bus, and supplies power to the vehicle load via the battery bus. A battery to be supplied; a power storage device for storing generated power from the generator; a first DC / DC converter in which one terminal is connected to the power generation bus; the other terminal is connected to the battery bus; and one terminal is connected to the power generation bus And a second DC / DC converter having the other terminal connected to the power storage device (see, for example, Patent Document 2).

JP 2008-67504 A WO2011 / 046147

  However, in the above-described vehicle power supply system disclosed in Patent Document 2, when a motor generator is used as the generator, the drive power of the motor generator is always supplied through the second DC / DC converter when supplied from the power storage device. Therefore, the second DC / DC converter needs a large-sized one having an allowable power enough to withstand the driving power. In addition, when the in-vehicle load requires a large amount of power, the first and second DC / DC converters are connected in series in order to supply electric power from the power storage device to the in-vehicle load. Both DC / DC converters must have an allowable power sufficient to withstand the power required by the on-vehicle load.

  The present invention was made to solve such problems, and in a vehicle power supply system having a plurality of voltage converters, the connection method of the voltage converters is switched according to the situation, Power that exceeds the allowable power of each voltage converter can be supplied.

A power supply system for a vehicle according to the present invention converts a kinetic energy supplied from a vehicle or an internal combustion engine as a generator into electric energy to generate DC power, and uses the vehicle or the internal combustion engine as a motor based on the DC power. A motor generator to drive,
A first power storage device for supplying electric power to a vehicle-mounted load via a first power storage bus;
A second power storage device that exchanges power with the motor generator and supplies stored power to the in-vehicle load and the first power storage device;
A first end is connected to the motor generator via a power generation bus and a second end is connected to the second power storage device via a second power storage bus so that both the power generation bus and the second power storage bus are connected. A first voltage converter that performs voltage conversion in a direction;
A first end is connected to the second power storage device via the second power storage bus, and a second end is connected to an output bus, and the second power storage bus is connected to the second power storage bus and the output bus from the second power storage bus. A second voltage converter that performs voltage conversion in the direction of the output bus;
A first switch for opening and closing a connection line between the output bus and the first power storage bus;
A second switch for opening and closing a connection line between the output bus and the power generation bus;
A control circuit for controlling the motor generator, the first voltage converter, the second voltage converter, the first switch, and the second switch;
The first voltage converter is a constant voltage control type voltage converter that maintains its first end at a first target voltage, and the second voltage converter is a constant voltage controller that maintains its second end at a second target voltage. A voltage controlled voltage converter,
When the electric power of the second power storage device is supplied to the motor generator, the control circuit opens the first switch and closes the second switch so that the first voltage conversion is performed. And the second voltage converter can be connected in parallel between the second power storage bus and the power generation bus, and the first target voltage and the second target voltage are set to the same voltage value. is there.

The vehicle power supply system according to the present invention converts a kinetic energy supplied from a vehicle or an internal combustion engine as a generator into electric energy to generate DC power, and uses the vehicle or the internal combustion engine as a motor based on the DC power. A motor generator that drives the engine;
A first power storage device for supplying electric power to a vehicle-mounted load via a first power storage bus;
A second power storage device that exchanges power with the motor generator and supplies stored power to the in-vehicle load and the first power storage device;
A first end is connected to the motor generator via a power generation bus and a second end is connected to the second power storage device via a second power storage bus so that both the power generation bus and the second power storage bus are connected. A first voltage converter that performs voltage conversion in a direction;
A first end is connected to the second power storage device via the second power storage bus, and a second end is connected to an output bus, and the second power storage bus is connected to the second power storage bus and the output bus from the second power storage bus. A second voltage converter that performs voltage conversion in the direction of the output bus;
A first switch for opening and closing a connection line between the output bus and the first power storage bus;
A second switch for opening and closing a connection line between the output bus and the power generation bus;
A control circuit for controlling the motor generator, the first voltage converter, the second voltage converter, the first switch, and the second switch;
The first voltage converter is a constant voltage control type voltage converter that maintains its first end at a first target voltage, and the second voltage converter is a constant voltage controller that maintains its second end at a second target voltage. A voltage controlled voltage converter,
The control circuit, when supplying the electric power of the second power storage device to the in-vehicle load and the first power storage device, the first switch is closed and the second switch is closed, The first voltage converter and the second voltage converter can be connected in parallel between the second power storage bus and the first power storage bus, and the first target voltage and the second target voltage are the same. The voltage value is set.

The vehicle power supply system according to the present invention converts a kinetic energy supplied from a vehicle or an internal combustion engine as a generator into electric energy to generate DC power, and uses the vehicle or the internal combustion engine as a motor based on the DC power. A motor generator that drives the engine;
A first power storage device for supplying electric power to a vehicle-mounted load via a first power storage bus;
A second power storage device that exchanges power with the motor generator and supplies stored power to the in-vehicle load and the first power storage device;
A first end is connected to the motor generator via a power generation bus and a second end is connected to the second power storage device via a second power storage bus so that both the power generation bus and the second power storage bus are connected. A first voltage converter that performs voltage conversion in a direction;
A first terminal is connected to the second power storage device via the second power storage bus, and a second terminal is connected to the output bus to perform bidirectional voltage conversion between the second power storage bus and the output bus. A second voltage converter;
A first switch for opening and closing a connection line between the output bus and the first power storage bus;
A second switch for opening and closing a connection line between the output bus and the power generation bus;
A control circuit for controlling the motor generator, the first voltage converter, the second voltage converter, the first switch, and the second switch;
The first voltage converter is a constant voltage control type voltage converter that maintains its first end at a first target voltage, and the second voltage converter is a constant voltage controller that maintains its second end at a second target voltage. A voltage controlled voltage converter,
The control circuit, when supplying the generated power of the motor generator to the second power storage device, makes the first switch open and closes the second switch, the first voltage The converter and the second voltage converter can be connected in parallel between the power generation bus and the second power storage bus, and the first target voltage and the second target voltage are set to the same voltage value,
The first voltage converter boosts the voltage in the direction from the first end to the second end, and the second voltage converter boosts the voltage in the direction from the second end to the first end, or
The first voltage converter steps down the voltage in the direction from the first end to the second end, and the second voltage converter steps down the voltage in the direction from the second end to the first end.

A vehicle power supply system according to the present invention includes a generator that generates direct-current power by converting kinetic energy supplied from a vehicle or an internal combustion engine into electrical energy;
A first power storage device for supplying electric power to a vehicle-mounted load via a first power storage bus;
A second power storage device that transfers power to and from the generator and supplies stored power to the in-vehicle load and the first power storage device;
A first end is connected to the generator via a power generation bus, and a second end is connected to the second power storage device via a second power storage bus so that the power generation bus and the second power storage bus are bidirectional. A first voltage converter for performing voltage conversion on
A first end is connected to the second power storage device via the second power storage bus, and a second end is connected to the first power storage bus, and the second end is connected between the second power storage bus and the first power storage bus. A second voltage converter that performs voltage conversion from two storage buses to the first storage bus;
A third switch for opening and closing a connection line between the first power storage bus and the power generation bus;
A control circuit for controlling the generator, the first voltage converter, the second voltage converter, and the third switch;
The first voltage converter is a constant voltage control type voltage converter that maintains its first end at a first target voltage, and the second voltage converter is a constant voltage controller that maintains its second end at a second target voltage. A voltage controlled voltage converter,
The control circuit closes the third switch and supplies the first voltage converter and the second voltage when supplying the electric power of the second power storage device to the in-vehicle load and the first power storage device. The converter can be connected in parallel between the second power storage bus and the first power storage bus, and the first target voltage and the second target voltage are set to the same voltage value.

According to the present invention, the first and second voltage converters are provided with the first and second switches that allow the first and second voltage converters to be connected in parallel to the motor generator or the vehicle load. The stored power can be transmitted to either the motor generator or the in-vehicle load via the first and second voltage converters. Moreover, the electric power generated by the motor generator can be transmitted to the second power storage device via the first and second voltage converters. As a result, it is possible to transmit power exceeding the allowable power of the first and second voltage converters between the second power storage device and the motor generator or the vehicle load. As a result, the first and second voltage converters can be operated efficiently, and it is not necessary to increase the allowable power of each voltage converter, so that the size and weight can be reduced.

In addition, according to the present invention, the third switch that enables the first and second voltage converters to be connected in parallel to the vehicle-mounted load is provided. And it can transmit to vehicle-mounted load via a 2nd voltage converter. As a result, it is possible to transmit power exceeding the allowable power of the first and second voltage converters between the second power storage device and the on-vehicle load. As a result, the first and second voltage converters can be operated efficiently, and it is not necessary to increase the allowable power of each voltage converter, so that the size and weight can be reduced.

1 is a circuit block diagram showing a vehicle power supply system according to Embodiment 1 of the present invention. It is a circuit block diagram which shows the example of the 1st voltage converter used for Embodiment 1 of this invention. It is a circuit block diagram which shows the example of the 2nd voltage converter used for Embodiment 1 of this invention. It is a circuit block diagram which shows the vehicle power supply system which concerns on Embodiment 2 of this invention. It is a circuit block diagram which shows the example of the 1st voltage converter used for Embodiment 3 of this invention. It is a circuit block diagram which shows the example of the 2nd voltage converter used for Embodiment 3 of this invention.

Embodiment 1 FIG.
1 is a circuit block diagram showing a vehicle power supply system according to Embodiment 1 of the present invention. As shown in FIG. 1, the vehicular power supply system of the present embodiment converts kinetic energy supplied from a vehicle (not shown) or an internal combustion engine (not shown) as a generator into electric energy to generate DC power. And the motor generator 1 that drives the vehicle or the internal combustion engine based on DC power as a motor, and supplies power to the in-vehicle load 12 via a first power storage bus (hereinafter referred to as a battery bus) 11. A first power storage device (hereinafter referred to as a battery) 13, a second power storage device 2 that transmits and receives power to and from the motor generator 1, and supplies stored power to the in-vehicle load 12 and the battery 13, and the motor generator 1 The first end is connected to the power generation bus 8 and the second end is connected to the second power storage device 2 via the second power storage bus 9 to convert the voltage between the power generation bus 8 and the second power storage bus 9. The first power to perform The first terminal is connected to the converter 3 and the second power storage device 2 via the second power storage bus 9 and the second terminal is connected to the output bus 10 so that the voltage between the second power storage bus 9 and the output bus 10 is A second voltage converter 4 that performs conversion; a first switch 5 that opens and closes a connection line between the output bus 10 and the battery bus 11; and a second switch that opens and closes a connection line between the output bus 10 and the power generation bus 8. 2 switch 6, motor generator 1, first voltage converter 3, second voltage converter 4, first switch 5, and control circuit 7 that controls second switch 6.

  The motor generator 1 is rotationally driven by a vehicle or an internal combustion engine, generates DC power based on a power generation command from the control circuit 7, and outputs it to the power generation bus 8. Further, the motor generator 1 is driven to rotate based on the stored electric power of the second power storage device 2 based on the torque command from the control circuit 7 to drive the vehicle or the internal combustion engine.

  The first voltage converter 3 has a first end connected to the motor generator 1 via the power generation bus 8 and a second end connected to the second power storage device 2 via the power storage bus 9. When the motor generator 1 is driven by a vehicle or an internal combustion engine to generate power, the generated power is transmitted to the second power storage device 2, and when the motor generator 1 drives the vehicle or the internal combustion engine, the second The electric power stored in the power storage device 2 is transmitted to the motor generator 1. Therefore, the first voltage converter 3 needs to be a bidirectional voltage converter capable of transmitting power in both directions between the power generation bus 8 and the second power storage bus 9.

The first voltage converter 3 uses a constant voltage control type voltage converter that maintains a first end at a predetermined first target voltage (hereinafter referred to as a target voltage V1_ref). As such a voltage converter, for example, a general voltage converter such as a step-up / step-down chopper circuit that feedback-controls the voltage at the first end can be used.
Here, if (voltage change at the first end) / (current change at the first end) is considered as the input impedance of the first voltage converter 3, the first voltage converter 3 is independent of the current at the first end. Since the voltage at the first end is kept constant, it can be regarded as a voltage converter with a low input impedance.

  FIG. 2 is a circuit configuration diagram illustrating an example of the first voltage converter 3. In FIG. 2, the first end 31 of the first voltage converter 3 is connected to the power generation bus 8, and the second end 32 is connected to the second power storage bus 9. The voltage V1 detected at the first end 31 of the first voltage converter 3 is compared with the target voltage V1_ref output from the control circuit 7 by the subtractor 33, and the deviation V1e is output to the PID calculator 34. The PID calculator 34 performs a PID calculation based on the deviation V1e and outputs a duty signal as an operation amount. The PWM generator 35 generates a PWM signal according to the duty signal from the PID calculator 34. The PWM signal is input to the gates of switching elements Q1H, Q1L, Q2H, and Q2L such as FETs and IGBTs through a gate drive amplifier, and controls on / off of each switching element Q1H, Q1L, Q2H, and Q2L. Note that L is an inductor, and Ci and Co are capacitors.

  The second voltage converter 4 has a first end connected to the second power storage device 2 via the second power storage bus 9, and a second end connected to the first end 51 of the first switch 5 and the second power via the output bus 10. The second switch 6 is connected to the second end 62. The second voltage converter 4 is a unidirectional voltage converter capable of transmitting power from the first end to the second end in order to transmit the power stored in the second power storage device 2 to the output bus 10. However, a bidirectional voltage converter capable of transmitting power in both directions between the first end and the second end may be used.

  The second voltage converter 4 is a constant voltage control type voltage converter that maintains the second end at a predetermined second target voltage (hereinafter referred to as target voltage V2_ref). As such a voltage converter, for example, a general voltage converter such as a step-up / step-down chopper circuit that feedback-controls the voltage at the second end can be used. The predetermined target voltage V2_ref is set based on the rated voltage of the battery 13. For example, if a lead storage battery having a rated voltage of 12V is used as the battery 13, the target voltage is generally set to about 14V.

  FIG. 3 is a circuit configuration diagram showing an example of the second voltage converter 4. In this example, a bidirectional buck-boost chopper is used as the second voltage converter 4. In FIG. 3, the first end 41 of the second voltage converter 4 is connected to the second power storage bus 9, and the second end 42 is connected to the output bus 10. The voltage V2 detected at the second end 42 of the second voltage converter 4 is compared with the target voltage V2_ref output from the control circuit 7 by the subtractor 43, and the deviation V2e is output to the PID calculator 44. The PID calculator 44 performs a PID calculation based on the deviation V2e and outputs a duty signal as an operation amount. The PWM generator 45 generates a PWM signal according to the duty signal from the PID calculator 44. The PWM signal is input to the gates of switching elements Q1H, Q1L, Q2H, and Q2L such as FETs and IGBTs through a gate drive amplifier, and controls on / off of each switching element Q1H, Q1L, Q2H, and Q2L. Note that L is an inductor, and Ci and Co are capacitors.

  As described above, the first switch 51 has the first end 51 connected to the output bus 10 and the second end connected to the battery 13 and the battery bus 11 on the vehicle load 12 side. When supplying the electric power stored in the second power storage device 2 to the in-vehicle load 12 via the second voltage converter 4, the first switch 5 is closed.

  As described above, the second switch 6 has the second end 62 connected to the output bus 10 and the first end 61 connected to the power generation bus 8. When the electric power stored in the second power storage device 2 is supplied to the motor generator 1 via the first voltage converter 3 and the second voltage converter 4, the second switch 6 is closed. The first switch 5 is opened. When the electric power generated by the motor generator 1 is stored in the second power storage device 2 via the first voltage converter 3, the second switch 6 is opened.

  When the first switch 5 is opened and the second switch 6 is closed as described above, the first end of the first voltage converter 3 and the second end of the second voltage converter 4 are connected to the motor generator 1. Connected. At this time, by setting the target voltage V1_ref at the first end of the first voltage converter 3 and the target voltage V2_ref at the second end of the second voltage converter 4 to the same value, the first voltage converter 3 and the first voltage converter 3 The electric power stored in the second power storage device 2 can be transmitted to the motor generator 1 by operating the two-voltage converter 4 in parallel.

  The second power storage device 2 can use an electric storage device having a large capacity such as an electric double layer capacitor or a storage battery such as a lithium ion storage battery or a nickel hydride storage battery. The charging voltage Vc of the second power storage device 2 becomes a rated voltage when a storage battery is used, and when an electric double layer capacitor is used, the charging voltage Vc is calculated from the capacitor capacity C, the initial voltage Vc0, and the charging current Ic of the capacitor. It is obtained by the formula.

  Vc (t) = ∫ (Ic / C) dt + Vc0 (1)

  Here, the charging current Ic of the capacitor is determined by the following equation from the current I1o output from the second end of the first voltage converter 3 and the current I2i input to the first end of the second voltage converter 4.

  Ic = I1o-I2i (2)

  By using a constant voltage control type voltage converter as the first voltage converter 3, the voltage Vmg of the power generation bus 8 can be maintained at a predetermined voltage. In this way, the voltage Vmg of the power generation bus 8 can be uniquely determined because the first voltage converter 3 having a low input impedance is connected to the power generation bus 8 which is one circuit connection point. It is.

  The motor generator 1 is driven by the engine when the engine is in an operating state to generate power, and does not generate power when the engine is in a stopped state. When the engine is started from the stopped state to the operating state, the motor generator 1 starts the engine using the electric power stored in the second power storage device 2.

  The motor generator 1 may be controlled using a known control method. For example, when the motor generator 1 performs power generation, the motor generator 1 receives a power generation command from the control circuit 7 and generates power. When the motor generator 1 drives the engine, the motor generator 1 1 is driven by receiving a torque command from the control circuit 7.

  The control circuit 7 includes a control command for the motor generator 1, a target voltage V1_ref command for the first voltage converter 3, a target voltage V2_ref command for the second voltage converter 4, an open / close command for the first switch 5, 2 Outputs an open / close command for the switch 6. The control of the vehicle power supply system by the control circuit 7 is performed based on the vehicle state. The vehicle state refers to vehicle speed, engine torque, voltage of the battery 13 and the second power storage device 2, and the like, which are detected by a known method and input to the control circuit 7 as vehicle state information 70.

  The power generation output of the motor generator 1 is changed according to the vehicle state. When the vehicle is being braked and there is excessive engine torque, the power generation output is increased and the second power storage device 2 is quickly charged. However, when it is not preferable to perform additional charging, such as when the charging state of the second power storage device 2 is full, the power generation output is not necessarily increased. Further, if there is no excessive engine torque because the vehicle is not braking, and the state of charge of the second power storage device 2 is not extremely low, the generated power is made zero, and the state of charge of the second power storage device 2 is When it is extremely low, it generates the electric power required by the vehicle load 12. By changing the power generation output according to the vehicle state as described above, the surplus engine torque can be used efficiently, so the amount of fuel used is reduced.

  When the first switch 5 is closed and connected to the battery 13 and the vehicle load 12 via the battery bus 11, the target voltage V2_ref at the second end of the second voltage converter 4 is the battery 13 as described above. Set based on the rated voltage. On the other hand, when the first switch 5 is opened and the second switch 6 is closed, the first voltage converter 3 and the second voltage converter 4 are connected in parallel to electrically drive the stored power of the second power storage device 2. Since the vehicle 1 or the internal combustion engine is driven by transmitting power to the generator 1, the target voltage V1_ref of the first voltage converter 3 and the target voltage V2_ref of the second voltage converter 4 are set to the same voltage value, and the setting is made. The value is a voltage value sufficient to drive the vehicle or the internal combustion engine.

  As described above, the opening / closing command of the first switch 5 is opened when power is transmitted to the motor generator 1 and is closed otherwise. The opening / closing command for the second switch 6 is closed when power is transmitted to the motor generator 1 as described above, and is closed otherwise.

  However, when a bidirectional voltage converter is used for the second voltage converter 4, charging from the motor generator 1 to the second power storage device 2 is performed using the first voltage converter 3 and the second voltage converter 4. It is possible to connect in parallel, and in such an operation, the second switch 6 is closed and the first switch 5 is opened.

  Furthermore, power transmission from the second power storage device 2 to the in-vehicle load 12 and the battery 13 can be performed by connecting the first voltage converter 3 and the second voltage converter 4 in parallel. In this case, the second switch 6 is closed and the first switch 5 is closed.

  As described above, according to the present embodiment, the first and second switches that enable the first and second voltage converters 3 and 4 to be connected in parallel to the motor generator 1 or the vehicle load 12. 5 and 6, the power stored in the second power storage device 2 can be transmitted to either the motor generator 1 or the in-vehicle load 12 via the first and second voltage converters 3 and 4. . Further, the electric power generated by the motor generator 1 can be transmitted to the second power storage device 2 via the first and second voltage converters 3 and 4. As a result, it is possible to transmit power exceeding the allowable power of the first and second voltage converters 3 and 4 between the second power storage device 2 and the motor generator 1 or the on-vehicle load 12. As a result, the first and second voltage converters 3 and 4 can be operated efficiently, and it is not necessary to increase the allowable power of each voltage converter 3 and 4, thereby reducing the size and weight.

Embodiment 2. FIG.
FIG. 4 is a circuit configuration diagram of a vehicle power supply system according to Embodiment 2 of the present invention. As shown in FIG. 4, the vehicle power supply system of the present embodiment converts kinetic energy supplied from a vehicle (not shown) or an internal combustion engine (not shown) into electrical energy to generate DC power. The generator 14, a first power storage device (hereinafter referred to as a battery) 13 that supplies power to the in-vehicle load 12 through a first power storage bus (hereinafter referred to as a battery bus) 11, and the power transfer to and from the generator 14 And the second power storage device 2 that supplies the stored power to the on-vehicle load 12 and the battery 13, and the first end is connected to the generator 14 via the power generation bus 8 and the second power storage device 2 is connected to the second power storage device 2. A first voltage converter 3 that performs voltage conversion between the power generation bus 8 and the second power storage bus 9 with the second end connected via the bus 9 and the second power storage device 2 via the second power storage bus 9 One end is connected to the battery bus 11 A second voltage converter 4 that performs voltage conversion between the second power storage bus 9 and the battery bus 11 with two ends connected thereto, and a third switch 15 that opens and closes a connection line between the battery bus 11 and the power generation bus 8 , A generator 14, a first voltage converter 3, a second voltage converter 4, and a control circuit 7 that controls the third switch 15.

  In the vehicular power supply system of the second embodiment shown in FIG. 4, the motor generator 1 is replaced with a generator 14 as compared with the vehicular power supply system of the first embodiment, and the output bus 10, the first switch 5, The second switch 6 is omitted, the second end of the second voltage converter 4 is connected to the battery bus 11, and a third switch 15 that opens and closes the connection line between the battery bus 11 and the power generation bus 8 is added. ing. Other components and their functions are the same as those in the first embodiment.

  In the present embodiment, when the third switch 15 is opened, the power generated by the generator 14 is stored in the second power storage device 2 via the first voltage converter 3, and the power stored in the second power storage device 2 is further stored. It can be supplied to the battery bus 11 via the second voltage converter 4. On the other hand, when the third switch 15 is closed, the power generation bus 8 and the battery bus 11 are connected, so that the first voltage converter 3 and the second voltage converter 4 are connected in parallel. If such a connection method is taken, the stored power of the second power storage device 2 can be supplied to the battery bus 11 via the first voltage converter 3 and the second voltage converter 4. Therefore, it is possible to supply power exceeding the allowable power of the first voltage converter 3 and the second voltage converter 4 from the second power storage device 2 to the battery bus 11.

  When the in-vehicle load 12 requires a large amount of power, the power stored in the second power storage device 2 is supplied to the battery bus 11 via the first voltage converter 3 and the second voltage converter 4 as described above. Moreover, since the voltage drop of the battery bus 11 can be suppressed, the effect of preventing the instantaneous stop of the in-vehicle load 12 is obtained.

  The case where the in-vehicle load 12 requires large electric power is, for example, a case where a starter (starting motor) is driven. Since the starter is for starting the engine, when the starter operates, the engine is stopped and the power generation of the generator 14 is also stopped. Therefore, by closing the third switch 15 and connecting the first voltage converter 3 and the second voltage converter 4 in parallel as described above, the power supplied from the second power storage device 2 to the starter is reduced. There is an increasing effect.

  When the first voltage converter 3 and the second voltage converter 4 are connected in parallel as described above, the target voltage V2_ref at the second end of the second voltage converter 4 and the first voltage converter 3 The target voltage V1_ref at the first end is set to the same voltage value, and the set value is set based on the rated voltage of the battery 13.

  In addition, when it is the vehicle-mounted load 12 and devices other than the starter require large power, the generator 14 connects the first voltage converter 3 and the second voltage converter 4 in parallel to the battery bus 11. When power is supplied, it does not matter whether power generation is performed or not.

  As described above, according to the present embodiment, since the third switch 15 that allows the first and second voltage converters 3 and 4 to be connected in parallel to the vehicle-mounted load 12 is provided, 2 The power stored in the power storage device 2 can be transmitted to the in-vehicle load 12 via the first and second voltage converters 3 and 4. As a result, it is possible to transmit power exceeding the allowable power of the first and second voltage converters 3 and 4 between the second power storage device 2 and the vehicle-mounted load 12. As a result, the first and second voltage converters 3 and 4 can be operated efficiently, and it is not necessary to increase the allowable power of each voltage converter 3 and 4, thereby reducing the size and weight.

Embodiment 3 FIG.
In the third embodiment, in the vehicular power supply system having the same configuration as that of the first or second embodiment, a step-up voltage converter is used for the first voltage converter 3 and the second voltage converter 4 is used. A step-down voltage converter is used, or a step-down voltage converter is used for the first voltage converter 3 and a step-up voltage converter is used for the second voltage converter 4.

  The step-up voltage converter used for the first voltage converter 3 or the second voltage converter 4 boosts the voltage from the first end to the second end, and from the second end to the first end. Is a voltage converter capable of stepping down the voltage. Similarly, the step-down voltage converters used for the first voltage converter 3 or the second voltage converter 4 step down the voltage in the direction from the first end to the second end, respectively, and from the second end to the first end. The voltage converter is capable of boosting the voltage in the direction of the end.

  In the vehicular power supply system of the first embodiment, when the second switch 6 is opened and the first switch 5 is closed, the electric power generated by the motor generator 1 is supplied to the second power storage bus via the first voltage converter 3. 9 is further transmitted from the second power storage bus 9 to the output bus 10 via the second voltage converter 4. At this time, if the first voltage converter 3 is a step-up voltage converter and the second voltage converter 4 is a step-down voltage converter, the generated power of the motor generator 1 is transmitted to the output bus 10. In the process, the voltage is boosted by the first voltage converter 3 and subsequently lowered by the second voltage converter 4. On the other hand, if the first voltage converter 3 is a step-down voltage converter and the second voltage converter 4 is a step-up voltage converter, the generated power of the motor generator 1 is transmitted to the output bus 10. In the process, the voltage is stepped down by the first voltage converter 3 and then boosted by the second voltage converter 4.

  In the vehicle power supply system of the first embodiment, when the first switch 5 is opened and the second switch 6 is closed, the first end of the first voltage converter 3 and the second voltage converter 4 The second end is connected to the motor generator 1. At this time, the target voltage V1_ref at the first end of the first voltage converter 3 and the target voltage V2_ref at the second end of the second voltage converter 4 are set to the same value, so that the second power storage device 2 is charged. The transmitted power can be transmitted to the motor generator 1 by operating the first voltage converter 3 and the second voltage converter 4 in parallel. Here, as a combination of the first voltage converter 3 and the second voltage converter 4, a combination of a boost type and a step-down type, or a combination of a step-down type and a boost type, the first voltage converter 3 as described above is used. Since the first end and the second end of the second voltage converter 4 are connected to the motor generator 1, the first voltage converter 3 and the second voltage converter 4 are connected to the motor generator 1. The power of the second power storage device 2 can be stepped down or boosted for transmission.

  That is, as the first voltage converter 3 and the second voltage converter 4, a step-up / step-down voltage converter is used by combining different voltage converters such as a step-up type and a step-down type or a step-down type and a step-up type. Even if it is not, it is possible to realize the vehicle power supply system of the first embodiment. The step-up or step-down voltage converter has a simpler circuit than the step-up / step-down voltage converter, and thus contributes to the miniaturization of the vehicle power supply system.

  Here, an example in which a step-down voltage converter is used as the first voltage converter 3 is shown in FIG. 5, and an example in which a step-up voltage converter is used as the second voltage converter 4 is shown in FIG.

  In FIG. 5, the first end 31 of the first voltage converter 3 is connected to the power generation bus 8, and the second end 32 is connected to the second power storage bus 9. The voltage V1 detected at the first end 31 of the first voltage converter 3 is compared with the target voltage V1_ref output from the control circuit 7 by the subtractor 33, and the deviation V1e is output to the PID calculator 34. The PID calculator 34 performs a PID calculation based on the deviation V1e and outputs a duty signal as an operation amount. The PWM generator 35 generates a PWM signal according to the duty signal from the PID calculator 34. The PWM signal is input to the gates of switching elements Q1H and Q1L such as FETs and IGBTs through a gate drive amplifier, and controls on / off of each switching element Q1H and Q1L.

  In FIG. 6, the first end 41 of the second voltage converter 4 is connected to the second power storage bus 9, and the second end 42 is connected to the output bus 10. The voltage V2 detected at the second end 42 of the second voltage converter 4 is compared with the target voltage V2_ref output from the control circuit 7 by the subtractor 43, and the deviation V2e is output to the PID calculator 44. The PID calculator 44 performs a PID calculation based on the deviation V2e and outputs a duty signal as an operation amount. The PWM generator 45 generates a PWM signal according to the duty signal from the PID calculator 44. The PWM signal is input to the gates of switching elements Q2H and Q2L such as FETs and IGBTs through a gate drive amplifier, and controls on / off of each switching element Q2H and Q2L.

  Similarly, in the second embodiment, the first voltage converter 3 and the second voltage converter 4 are different voltage types such as a step-up type and a step-down type voltage converter or a step-down type and a step-up type voltage converter. Converters can be combined. Then, the vehicle power supply system of the second embodiment can be realized without using the step-up / step-down voltage converter as the first voltage converter 3 and the second voltage converter 4.

  For example, when a step-up voltage converter and a step-down voltage converter are used as the first voltage converter 3 and the second voltage converter 4, respectively, when the third switch 15 is opened, the generated power of the generator 14 is The voltage is boosted by one voltage converter 3, is stepped down by the second voltage converter 4 via the second power storage bus 9, and is output to the battery bus 11. On the other hand, when the third switch 15 is closed, the power generation bus 8 and the battery bus 11 are connected, and the first voltage converter 3 and the second voltage converter 4 are connected in parallel. The voltage can be stepped down via the 1 voltage converter 3 and the second voltage converter 4 to transmit power to the battery bus 11. In this case, the target voltage V1_ref at the first end of the first voltage converter 3 and the target voltage V2_ref at the second end of the second voltage converter 4 are set to the same voltage value based on the rated voltage of the battery 13. Further, the power can be boosted from the generator 14 via the first voltage converter 3 and the second voltage converter 4 to transmit power to the second power storage device 2.

  Further, when a step-down voltage converter and a step-up voltage converter are used as the first voltage converter 3 and the second voltage converter 4, respectively, the generated power of the generator 14 in the state where the third switch 15 is opened is The voltage is stepped down by one voltage converter 3, boosted by the second voltage converter 4 via the second power storage bus 9, and output to the battery bus 11. On the other hand, in the state where the third switch 15 is closed, the voltage can be boosted from the second power storage device 2 via the first voltage converter 3 and the second voltage converter 4 to transmit power to the battery bus 11. In this case, the target voltage V1_ref at the first end of the first voltage converter 3 and the target voltage V2_ref at the second end of the second voltage converter 4 are set to the same voltage value based on the rated voltage of the battery 13. In addition, power can be transmitted from the generator 14 to the second power storage device 2 by stepping down through the first voltage converter 3 and the second voltage converter 4.

  As described above, in the present embodiment, in the vehicle power supply system of Embodiment 1 or 2, the first voltage converter boosts the voltage in the direction from the first end to the second end, and the first voltage from the second end. A voltage converter that steps down the voltage in the direction of the end, and the second voltage converter steps down the voltage in the direction from the first end to the second end and boosts the voltage in the direction from the second end to the first end. The first voltage converter is a voltage converter that steps down the voltage in the direction from the first end to the second end and steps up the voltage in the direction from the second end to the first end; The voltage converter is a voltage converter that increases the voltage in the direction from the first end to the second end and decreases the voltage in the direction from the second end to the first end. As a result, the system of Embodiment 1 or 2 can be realized without using a step-up / step-down voltage converter, which simplifies the circuit and contributes to the miniaturization of the system.

  It should be noted that the present invention can be freely combined with each other within the scope of the invention, and each embodiment can be appropriately modified or omitted.

1 motor generator, 2 second power storage device, 3 first voltage converter, 4 second voltage converter,
5 First switch, 6 Second switch, 7 Control circuit, 8 Power generation bus,
9 second power storage bus, 10 output bus, 11 first power storage bus (battery bus),
12 on-vehicle load, 13 first power storage device (battery), 14 generator,
15 Third switch.

Claims (9)

A motor generator that generates dc power by converting kinetic energy supplied from a vehicle or an internal combustion engine as a generator into electric energy, and that drives the vehicle or the internal combustion engine based on the dc power as a motor;
A first power storage device for supplying electric power to a vehicle-mounted load via a first power storage bus;
A second power storage device that exchanges power with the motor generator and supplies stored power to the in-vehicle load and the first power storage device;
A first end is connected to the motor generator via a power generation bus and a second end is connected to the second power storage device via a second power storage bus so that both the power generation bus and the second power storage bus are connected. A first voltage converter that performs voltage conversion in a direction ;
A first end is connected to the second power storage device via the second power storage bus, and a second end is connected to an output bus, and the second power storage bus is connected to the second power storage bus and the output bus from the second power storage bus. A second voltage converter that performs voltage conversion in the direction of the output bus ;
A first switch for opening and closing a connection line between the output bus and the first power storage bus;
A second switch for opening and closing a connection line between the output bus and the power generation bus;
A control circuit for controlling the motor generator, the first voltage converter, the second voltage converter, the first switch, and the second switch;
The first voltage converter is a constant voltage control type voltage converter that maintains its first end at a first target voltage, and the second voltage converter is a constant voltage controller that maintains its second end at a second target voltage. A voltage controlled voltage converter,
When the electric power of the second power storage device is supplied to the motor generator, the control circuit opens the first switch and closes the second switch so that the first voltage conversion is performed. And the second voltage converter can be connected in parallel between the second power storage bus and the power generation bus, and the first target voltage and the second target voltage are set to the same voltage value. Power system. A motor generator that generates dc power by converting kinetic energy supplied from a vehicle or an internal combustion engine as a generator into electric energy, and that drives the vehicle or the internal combustion engine based on the dc power as a motor;
A first power storage device for supplying electric power to a vehicle-mounted load via a first power storage bus;
A second power storage device that exchanges power with the motor generator and supplies stored power to the in-vehicle load and the first power storage device;
A first end is connected to the motor generator via a power generation bus and a second end is connected to the second power storage device via a second power storage bus so that both the power generation bus and the second power storage bus are connected. A first voltage converter that performs voltage conversion in a direction ;
A first end is connected to the second power storage device via the second power storage bus, and a second end is connected to an output bus, and the second power storage bus is connected to the second power storage bus and the output bus from the second power storage bus. A second voltage converter that performs voltage conversion in the direction of the output bus ;
A first switch for opening and closing a connection line between the output bus and the first power storage bus;
A second switch for opening and closing a connection line between the output bus and the power generation bus;
A control circuit for controlling the motor generator, the first voltage converter, the second voltage converter, the first switch, and the second switch;
The first voltage converter is a constant voltage control type voltage converter that maintains its first end at a first target voltage, and the second voltage converter is a constant voltage controller that maintains its second end at a second target voltage. A voltage controlled voltage converter,
The control circuit, when supplying the electric power of the second power storage device to the in-vehicle load and the first power storage device, the first switch is closed and the second switch is closed, The first voltage converter and the second voltage converter can be connected in parallel between the second power storage bus and the first power storage bus, and the first target voltage and the second target voltage are the same. Vehicle power supply system set to voltage value. A motor generator that generates dc power by converting kinetic energy supplied from a vehicle or an internal combustion engine as a generator into electric energy, and that drives the vehicle or the internal combustion engine based on the dc power as a motor;
A first power storage device for supplying electric power to a vehicle-mounted load via a first power storage bus;
A second power storage device that exchanges power with the motor generator and supplies stored power to the in-vehicle load and the first power storage device;
A first end is connected to the motor generator via a power generation bus and a second end is connected to the second power storage device via a second power storage bus so that both the power generation bus and the second power storage bus are connected. A first voltage converter that performs voltage conversion in a direction ;
A first terminal is connected to the second power storage device via the second power storage bus, and a second terminal is connected to the output bus to perform bidirectional voltage conversion between the second power storage bus and the output bus. A second voltage converter;
A first switch for opening and closing a connection line between the output bus and the first power storage bus;
A second switch for opening and closing a connection line between the output bus and the power generation bus;
A control circuit for controlling the motor generator, the first voltage converter, the second voltage converter, the first switch, and the second switch;
The first voltage converter is a constant voltage control type voltage converter that maintains its first end at a first target voltage, and the second voltage converter is a constant voltage controller that maintains its second end at a second target voltage. A voltage controlled voltage converter,
The control circuit, when supplying the generated power of the motor generator to the second power storage device, makes the first switch open and closes the second switch, the first voltage The converter and the second voltage converter can be connected in parallel between the power generation bus and the second power storage bus, and the first target voltage and the second target voltage are set to the same voltage value ,
The first voltage converter boosts the voltage in the direction from the first end to the second end, and the second voltage converter boosts the voltage in the direction from the second end to the first end, or
The first voltage converter steps down the voltage from the first end to the second end, and the second voltage converter steps down the voltage from the second end to the first end. system. The control circuit makes the first switch closed and the second switch open when supplying the electric power generated by the motor generator to the in-vehicle load and the first power storage device. The vehicle power supply system according to any one of claims 1 to 3. A generator that generates DC power by converting kinetic energy supplied from a vehicle or an internal combustion engine into electrical energy;
A first power storage device for supplying electric power to a vehicle-mounted load via a first power storage bus;
A second power storage device that transfers power to and from the generator and supplies stored power to the in-vehicle load and the first power storage device;
A first end is connected to the generator via a power generation bus, and a second end is connected to the second power storage device via a second power storage bus so that the power generation bus and the second power storage bus are bidirectional. A first voltage converter for performing voltage conversion on
A first end is connected to the second power storage device via the second power storage bus, and a second end is connected to the first power storage bus, and the second end is connected between the second power storage bus and the first power storage bus . A second voltage converter that performs voltage conversion from two storage buses to the first storage bus ;
A third switch for opening and closing a connection line between the first power storage bus and the power generation bus;
A control circuit for controlling the generator, the first voltage converter, the second voltage converter, and the third switch;
The first voltage converter is a constant voltage control type voltage converter that maintains its first end at a first target voltage, and the second voltage converter is a constant voltage controller that maintains its second end at a second target voltage. A voltage controlled voltage converter,
The control circuit closes the third switch and supplies the first voltage converter and the second voltage when supplying the electric power of the second power storage device to the in-vehicle load and the first power storage device. A vehicular power supply system in which a converter can be connected in parallel between the second power storage bus and the first power storage bus, and the first target voltage and the second target voltage are set to the same voltage value. 6. The vehicle power supply system according to claim 5, wherein the control circuit opens the third switch when supplying the generated power of the generator to the in-vehicle load and the first power storage device. 7. The vehicle power supply system according to claim 5, wherein the vehicle-mounted load requires electric power when starting the starter. The first voltage converter is a voltage converter that boosts the voltage in the direction from the first end to the second end and steps down the voltage in the direction from the second end to the first end.
8. The voltage converter according to claim 1, wherein the second voltage converter is a voltage converter that steps down the voltage in the direction from the first end to the second end and steps up the voltage in the direction from the second end to the first end. The vehicle power supply system according to any one of the preceding claims. The first voltage converter is a voltage converter that steps down the voltage from the first end to the second end and steps up the voltage from the second end to the first end,
8. The voltage converter according to claim 1, wherein the second voltage converter is a voltage converter that boosts the voltage in the direction from the first end to the second end and steps down the voltage in the direction from the second end to the first end. The vehicle power supply system according to any one of the preceding claims.

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