JP2019110656A - Power supply system - Google Patents

Abstract

To improve utilization efficiency of a device in a power supply system comprising a battery and a fuel cell.SOLUTION: In a power supply system comprising a battery and a fuel cell, a fuel cell converter comprises a pair of chopper circuits connected in parallel with each other and each including a reactor whose one end is connected with a positive electrode side of the fuel cell, an upper diode connected between the other end of the reactor and a positive electrode side of a load, a lower diode connected between the other end of the reactor and a negative electrode side of the fuel cell, and a lower switching element connected in parallel to the lower diode. At the fuel cell side from a connection point of the upper diode, the lower diode and the reactor in the pair of chopper circuits, a switching part for connecting and disconnecting between the fuel cell converter and the positive electrode side of the fuel cell is provided. The switching part can switch between a state where the fuel cell converter is connected with the positive electrode side of the fuel cell, and a state where the fuel cell converter is connected with an external connection part that can receive power supplied from an external AC power supply.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a power supply system.

  BACKGROUND In recent years, power supply systems including a battery, which is a secondary battery that stores electric power supplied to a load, and a fuel cell connected to the load in parallel with the battery, are used for various devices. For example, as described in Patent Document 1, in an electric vehicle traveling by the output of a drive motor driven mainly using electric power stored in a battery, the battery is generated using electric power generated by a fuel cell. 2. Description of the Related Art There are electric vehicles that can continue traveling while suppressing that the remaining capacity (SOC: State Of Charge) of the battery is reduced and the power is exhausted by charging. Such an electrically powered vehicle is also referred to as a fuel cell range extender type electrically powered vehicle. In a fuel cell range extender type electric vehicle, for example, the battery is charged by an external power supply, and the fuel cell is activated according to the decrease in the remaining capacity of the battery while the electric vehicle is traveling.

JP, 2014-143851, A

  By the way, in a power supply system including a battery and a fuel cell, it is considered desirable to improve the utilization efficiency of the device in the power supply system. Specifically, the power supply system described above may be provided with a converter having a boosting function for boosting the power output from the power source according to the voltage of the power source. For example, as such a converter, a battery converter for boosting the power stored in the battery or a fuel cell converter for boosting the power generated by the fuel cell may be provided. Here, in the power supply system, when the supply of power from the power source to the load is not performed, a situation may occur where the converter is not used. Such a situation causes a reduction in the utilization efficiency of the device in the power supply system. The reduction in the utilization efficiency of the device in the power supply system may cause an increase in the number of parts in the power supply system, which in turn may cause the power supply system to become larger.

  Therefore, the present invention has been made in view of the above problems, and an object of the present invention is to provide a new and improved apparatus capable of improving the utilization efficiency of a device in a power supply system including a battery and a fuel cell. Power supply system.

  To solve the above problems, according to one aspect of the present invention, a battery connected to a load and storing electric power supplied to the load, and a parallel-connected battery via a fuel cell converter capable of converting voltage A power supply system comprising: a fuel cell connected to the load; and an external connection portion capable of receiving power supplied from the external AC power supply in a state of being connected to an external AC power supply, the fuel cell converter comprising: Between a reactor whose one end is connected to the positive electrode side of the fuel cell, an upper diode connected between the other end of the reactor and the positive electrode side of the load, and between the other end of the reactor and the negative electrode side of the fuel cell A pair of chopper circuits provided in parallel with each other including a lower diode connected to the lower diode and a lower switching element connected in parallel to the lower diode; A switching unit for connecting and disconnecting the fuel cell converter and the positive electrode side of the fuel cell is provided on the fuel cell side from the connection point of upper diode, lower diode and reactor in a pair of chopper circuits of the converter, the fuel cell converter The switch unit can switch between the state in which the fuel cell converter is connected to the positive electrode side of the fuel cell and the state in which the fuel cell converter is connected to the external connection portion, and the operation of the fuel cell converter A power supply system is provided, comprising a controller for controlling

  In each of the pair of chopper circuits of the fuel cell converter, the upper switching element may be connected in parallel to the upper diode.

  The control device connects the fuel cell converter to the external connection portion to operate as a PWM rectifier when the external connection portion is connected to the external AC power supply, whereby the external connection from the external AC power supply is performed. The battery may be charged using power received via the unit.

  When the external connection unit is connected to an external alternating current load, the control device causes the fuel cell converter to be connected to the external connection unit to operate as a PWM inverter, whereby the storage power of the battery is converted to the external alternating current The load may be fed via the external connection.

  The control device may switch the lower switching elements of the pair of chopper circuits of the fuel cell converter so as to cause a phase difference when the fuel cell converter is operated to step up the voltage.

  The battery is connected to the load in parallel with the fuel cell and the fuel cell converter via a battery converter capable of converting a voltage, and the battery converter is a reactor whose one end is connected to the positive electrode side of the battery; An upper diode connected between the other end of the reactor and the positive electrode side of the load, an upper switching element connected in parallel with the upper diode, and a connection between the other end of the reactor and the negative electrode side of the battery Lower diode and a pair of chopper circuits provided in parallel with each other including a lower switching element connected in parallel to the lower diode, and the connection point between the upper diode, the lower diode and the reactor in the pair of chopper circuits of the battery converter On the battery side, the battery converter and the battery A switching unit for connecting and disconnecting to the pole side is provided, and the switching unit of the battery converter is in a state in which the battery converter is connected to the positive electrode side of the battery, and a state in which the battery converter is connected to the external connection unit And the controller may control the operation of the battery converter.

  When the external connection portion is connected to an external AC load, the control device causes the battery converter to be connected to the external connection portion to operate as a PWM inverter, whereby the power generated by the fuel cell is converted to the external AC. The load may be fed via the external connection.

  The control device may switch the lower switching elements of the pair of chopper circuits of the battery converter so as to cause a phase difference with each other when performing the boost operation of the battery converter.

  The control device may switch the upper switching elements of the pair of chopper circuits of the battery converter so as to generate a phase difference when the battery converter is operated to step down the battery converter.

  As described above, according to the present invention, it is possible to improve the utilization efficiency of the device in the power supply system including the battery and the fuel cell.

It is a schematic diagram which shows schematic structure of the power supply system which concerns on embodiment of this invention. It is a schematic diagram which shows the flow of the electric power in the power supply system which concerns on the embodiment at the time of driving | running | working of an electric vehicle. It is a figure for demonstrating the operation | movement of the fuel cell converter at the time of driving | running | working of an electric vehicle. It is a schematic diagram which shows the flow of the electric power in the power supply system which concerns on the embodiment at the time of the external charge of a battery. It is a figure for demonstrating the operation | movement of the fuel cell converter at the time of the external charge of a battery. It is a schematic diagram which shows the flow of the electric power in the power supply system which concerns on the embodiment at the time of the external electric power feeding to the external alternating current load which used the electrical storage electric power of the battery. It is a figure for demonstrating the operation | movement of the fuel cell converter at the time of the external electric power feeding to the external alternating current load using the electrical storage electric power of a battery. It is a schematic diagram which shows schematic structure of the power supply system which concerns on a 1st modification. It is a schematic diagram which shows schematic structure of the power supply system which concerns on a 2nd modification. It is a schematic diagram which shows schematic structure of the power supply system which concerns on an application example. It is a schematic diagram which shows the flow of the electric power in the power supply system which concerns on the application example at the time of driving | running | working of an electric vehicle. It is a schematic diagram which shows the flow of the electric power in the power supply system which concerns on the application example at the time of the external charge of a battery. It is a schematic diagram which shows the flow of the electric power in the power supply system which concerns on the application example at the time of the external electric power feeding to the external alternating current load using the electrical storage electric power of a battery. It is a schematic diagram which shows the flow of the electric power in the power supply system which concerns on the application example at the time of the external electric power feeding to the external alternating current load using the generated electric power of a fuel cell.

  The present invention will now be described more fully with reference to the accompanying drawings, in which exemplary embodiments of the invention are shown. In the present specification and the drawings, components having substantially the same functional configuration will be assigned the same reference numerals and redundant description will be omitted.

<1. Power supply system configuration>
First, the configuration of a power supply system 1 according to an embodiment of the present invention will be described with reference to FIG.

  The power supply system 1 is, for example, a system which is mounted on an electric vehicle and realizes power transmission between the battery 10 and the fuel cell 20 as a drive source of the electric vehicle and the drive motor 32.

  In addition, although such a power supply system 1 is demonstrated as one Embodiment below, the power supply system which concerns on this invention is not limited to such an example. For example, the power supply system according to the present invention may be mounted on devices other than electrically powered vehicles such as railways or other transport machines equipped with batteries and fuel cells. Further, the load 30 in the power supply system 1 includes the inverter 31 and the drive motor 32 as described later, but the load according to the present invention may be capable of consuming the supplied power, and the power supply system is mounted It may vary as appropriate depending on the device to be

  FIG. 1 is a schematic view showing a schematic configuration of a power supply system 1 according to the present embodiment.

  As shown in FIG. 1, the power supply system 1 includes a battery 10, a fuel cell 20, a load 30 including an inverter 31 and a drive motor 32, a fuel cell converter 50, an external connection unit 60, and a control device 100. Equipped with

  The electrically powered vehicle equipped with the power supply system 1 can travel with the drive motor 32 driven using the power stored in the battery 10 (also referred to as stored power) as a drive source. Further, the electric vehicle is used to charge the battery 10 using the electric power generated by the fuel cell 20 (also referred to as generated electric power), thereby suppressing the decrease in the remaining capacity SOC of the battery 10 and the exhaustion of the electric power. It is possible to continue traveling while.

  The power supply system 1 is mounted on, for example, a fuel cell range extender type electric vehicle. Specifically, in the power supply system 1 mounted on a fuel cell range extender type electric vehicle, the stored power of the battery 10 is mainly used for driving the drive motor 32, and the generated power of the fuel cell 20 is mainly used for the battery 10. Used for charging. The power generated by the fuel cell 20 may be used to drive the drive motor 32. For example, the power generated by the fuel cell 20 may be used to drive the drive motor 32 in addition to the power stored in the battery 10. The ratio of the frequency used to drive the drive motor 32 between the stored power of the battery 10 and the generated power of the fuel cell 20 is not particularly limited. Further, specifically, in power supply system 1 mounted on a fuel cell range extender type electric vehicle, battery 10 may be charged using power supplied from an external power supply of the electric vehicle.

  The battery 10 is a battery capable of charging and discharging electric power, and stores the electric power supplied to the drive motor 32. As the battery 10, for example, a secondary battery such as a lithium ion battery, a lithium ion polymer battery, a nickel hydrogen battery, a nickel cadmium battery, or a lead storage battery is used, but batteries other than these may be used.

  As shown in FIG. 1, the battery 10 is connected to the inverter 31. Therefore, the storage power of the battery 10 can be supplied to the drive motor 32 through the inverter 31. The stored power of the battery 10 may be supplied to various auxiliary devices provided in the motor-driven vehicle.

  Also, the battery 10 is charged using the power supplied to the battery 10. Specifically, battery 10 may be charged using the power generated by fuel cell 20. Also, the battery 10 can be charged using the electric power regenerated by the drive motor 32 (regenerative electric power). In addition, battery 10 may be charged using power received from an external AC power supply via external connection unit 60, as described later.

  The battery 10 is provided with a battery management system (BMS) 11. For example, the battery management device 11 calculates information such as the voltage of the battery 10 and the remaining capacity SOC, and outputs the information to the control device 100.

  The fuel cell 20 is a cell capable of generating electric power by reacting hydrogen gas and oxygen gas. For example, the fuel cell 20 generates low-voltage power as compared to the electromotive force of the battery 10. The fuel cell 20 is connected to a hydrogen tank (not shown), and the hydrogen tank is filled with, for example, high pressure hydrogen supplied to the fuel cell 20. Hydrogen gas is supplied from the hydrogen tank to the fuel cell 20 by a motor pump or the like (not shown). Further, air as an oxygen gas is supplied to the fuel cell 20 by a compressor (not shown) or the like. By controlling the supply amount of hydrogen gas and oxygen gas to the fuel cell 20, the output of the fuel cell 20 is controlled.

  As shown in FIG. 1, the fuel cell 20 is connected to the inverter 31 in parallel with the battery 10 via a fuel cell converter 50 capable of converting a voltage. Therefore, the power generated by the fuel cell 20 can be supplied to the battery 10 through the fuel cell converter 50. Further, the power generated by the fuel cell 20 can be supplied to the inverter 31 through the fuel cell converter 50.

  In addition, between the positive electrode side of the fuel cell 20 and the fuel cell converter 50 (specifically, from the connecting point P59 of the chopper circuit 51, the chopper circuit 52 and the positive electrode side of the fuel cell 20 of the fuel cell converter 50 described later) 20) may be provided with a diode 92 for restricting the direction of the current in one direction from the positive electrode side of the fuel cell 20 to the fuel cell converter 50 from the viewpoint of preventing the backflow of the current to the fuel cell 20.

  The load 30 consumes the power supplied from the battery 10. As shown in FIG. 1, the load 30 includes an inverter 31 and a drive motor 32.

  The inverter 31 is a power conversion device capable of converting power between DC power and AC power, and has a function of performing bidirectional power conversion between the drive motor 32 and the power source side such as the battery 10 or the like. .

  The inverter 31 includes, for example, a three-phase bridge circuit. The inverter 31 is provided with a switching element, and the operation of the switching element is controlled to control conversion of power by the inverter 31.

  As shown in FIG. 1, the inverter 31 is connected to the drive motor 32. Therefore, bidirectional power conversion via the inverter 31 can be performed between the drive motor 32 and the power source side of the battery 10 or the like. For example, the inverter 31 can convert supplied DC power into AC power and supply the AC power to the drive motor 32. Further, the inverter 31 can convert alternating current power regenerated and generated by the drive motor 32 into direct current power and supply the direct current power to the battery 10. A smoothing capacitor 91 may be connected in parallel to the inverter 31 from the viewpoint of smoothing the direct current flowing in the power supply system 1.

  The driving motor 32 can output power by being driven (powering drive) using the supplied power. As the drive motor 32, for example, a three-phase alternating current motor is used. The power output from the drive motor 32 is transmitted to, for example, a differential device (not shown), and distributed and transmitted to the pair of left and right drive wheels by the differential device. In addition, the drive motor 32 may have a function (regeneration function) as a generator that is regeneratively driven at the time of deceleration of the electric vehicle and generates electric power using rotational energy of the wheels.

  The fuel cell converter 50 is a power converter capable of converting a voltage, and has a function of boosting the generated power of the fuel cell 20 and supplying it to the load 30 side. The fuel cell converter 50 is provided with a switching element, and the operation of the switching element is controlled to control the conversion of power by the fuel cell converter 50.

  As shown in FIG. 1, the fuel cell converter 50 includes a pair of chopper circuits 51 and 52 provided in parallel to each other.

  Chopper circuit 51 includes an upper switching element 511, a lower switching element 512, an upper diode 513, a lower diode 514, and a reactor 515. One end of a reactor 515 is connected to the positive electrode side of the fuel cell 20. The upper diode 513 is a diode connected between the other end of the reactor 515 and the positive electrode side of the inverter 31. Specifically, the upper diode 513 regulates the direction of the current in one direction from the other end of the reactor 515 toward the positive electrode side of the inverter 31. The lower diode 514 is a diode connected between the other end of the reactor 515 and the negative electrode side of the fuel cell 20. Specifically, lower diode 514 regulates the direction of current in one direction from the negative electrode side of fuel cell 20 to the other end of reactor 515. The upper switching element 511 is a switching element connected in parallel to the upper diode 513. The lower switching element 512 is a switching element connected in parallel to the lower diode 514.

  Chopper circuit 52 includes an upper switching element 521, a lower switching element 522, an upper diode 523, a lower diode 524, and a reactor 525. One end of a reactor 525 is connected to the positive electrode side of the fuel cell 20. The upper diode 523 is a diode connected between the other end of the reactor 525 and the positive electrode side of the inverter 31. Specifically, the upper diode 523 regulates the direction of the current in one direction from the other end of the reactor 525 to the positive electrode side of the inverter 31. The lower diode 524 is a diode connected between the other end of the reactor 525 and the negative electrode side of the fuel cell 20. Specifically, lower diode 524 regulates the direction of current in one direction from the negative electrode side of fuel cell 20 to the other end of reactor 525. The upper switching element 521 is a switching element connected in parallel to the upper diode 523. The lower switching element 522 is a switching element connected in parallel to the lower diode 524.

  As each switching element of the chopper circuits 51 and 52, for example, a MOSFET (Metal Oxide Semiconductor Field Effect Transistor), an IGBT (Insulated Gate Bipolar Transistor) or the like is used.

  In each chopper circuit of the fuel cell converter 50, the lower switching element 512 (522) performs a switching operation (in other words, an operation of repeating ON and OFF) in a state where the upper switching element 511 (521) is maintained OFF. Thus, the power generated by the fuel cell 20 is boosted and supplied to the load 30 side. At this time, in each chopper circuit of fuel cell converter 50, magnetic energy is stored in reactor 515 (525) when lower switching element 512 (522) is ON, and the lower switching element 512 (522) is OFF. The magnetic energy is released from the reactor 515 (525).

  Here, on the fuel cell 20 side from the connection points P51 and P52 of the upper diode, lower diode and reactor in the pair of chopper circuits 51 and 52 of the fuel cell converter 50, the fuel cell converter 50 and the positive electrode side of the fuel cell 20 are A switching unit 59 is provided. The switching unit 59 can switch between a state in which the fuel cell converter 50 is connected to the positive electrode side of the fuel cell 20 and a state in which the fuel cell converter 50 is connected to the external connection portion 60.

  As shown in FIG. 1, the switching unit 59 includes a switch 591 and a switch 592.

  The switch 591 is provided on the fuel cell 20 side with respect to the connection point P51 of the upper diode 513, the lower diode 514 and the reactor 515 in the chopper circuit 51, and connects the chopper circuit 51 and the positive electrode side of the fuel cell 20 at the installation position. For example, the switch 591 is provided between the chopper circuit 51, the chopper circuit 52, and the connection point P59 on the positive electrode side of the fuel cell 20 and the reactor 515. Further, the switch 591 can connect the chopper circuit 51 and one of the pole sides of the external connection portion 60 at the installation position, and the chopper circuit 51 is connected to the positive electrode side of the fuel cell 20. It can be switched to the state of being connected to one of the pole sides of the external connection portion 60.

  The switch 592 is provided on the fuel cell 20 side from the connection point P52 of the upper diode 523, the lower diode 524 and the reactor 525 in the chopper circuit 52, and connects the chopper circuit 52 and the positive electrode side of the fuel cell 20 at the installation position. For example, the switch 592 is provided between the reactor 525 and the connection point P59 on the positive electrode side of the chopper circuit 51, the chopper circuit 52, and the fuel cell 20. The switch 592 can connect the chopper circuit 52 and the other pole side of the external connection unit 60 at the installation position, and the chopper circuit 52 is connected to the positive electrode side of the fuel cell 20. It is possible to switch to the state of being connected to the other pole side of the external connection portion 60.

  In the state where the chopper circuit 51 is connected to the positive electrode side of the fuel cell 20 by the switch 591 and the chopper circuit 52 is connected to the positive electrode side of the fuel cell 20 by the switch 592 It corresponds to the state of being connected to On the other hand, the fuel cell converter is in a state where the chopper circuit 51 is connected to one pole side of the external connection section 60 by the switch 591 and the chopper circuit 52 is connected to the other pole side of the external connection section 60 by the switch 592 50 corresponds to a state in which the external connection unit 60 is connected.

  The fuel cell converter 50 can execute power conversion between the external connection portion 60 and the load 30 side in a state where the fuel cell converter 50 is connected to the external connection portion 60. For example, the fuel cell converter 50 can convert alternating current supplied from the external connection unit 60 into direct current power and supply it to the load 30 side. Further, the fuel cell converter 50 can convert DC power supplied from the load 30 side into AC power and supply the AC power to the external connection unit 60. The power conversion by the fuel cell converter 50 in a state in which the fuel cell converter 50 is connected to the external connection unit 60 will be described in detail later.

  The external connection unit 60 can be connected to an external device that is an external device of the device (in the present embodiment, the electric vehicle) on which the power supply system 1 is mounted, and in the state of being connected to the external device Receive power from external devices. Specifically, the external connection unit 60 receives single-phase AC power between the power supply system 1 and an external device.

  For example, the external connection unit 60 can receive power supplied from the external AC power supply in a state of being connected to the external AC power supply that is an external AC power supply. Also, for example, the external connection unit 60 can supply power to the external AC load in a state of being connected to the external AC load which is an external AC load. The external AC load may be various home loads, for example, in a system called V2H (Vehicle to Home).

  As shown in FIG. 1, the external connection unit 60 includes, for example, an external circuit 61, an internal circuit 62, and a transformer 63. The external side circuit 61 is a circuit provided so as to be connectable to an external device outside the electrically powered vehicle, and has a pair of poles. The internal circuit 62 is a circuit provided so as to be connectable to the fuel cell converter 50, and has a pair of poles. The transformer 63 is a transformer capable of converting a voltage between the external circuit 61 and the internal circuit 62. Further, the external circuit 61 and the internal circuit 62 can be insulated by the transformer 63.

  For example, in a state where the external alternating current power supply is connected to the external side circuit 61, power is supplied from the external alternating current power supply to the external side circuit 61. The power is transformed by the transformer 63 and then supplied to the internal circuit 62. At this time, when the fuel cell converter 50 is connected to the external connection unit 60, power can be supplied from the internal circuit 62 to the fuel cell converter 50. Also, for example, when the fuel cell converter 50 is connected to the external connection unit 60 in a state where an external AC load is connected to the external side circuit 61, power can be supplied from the fuel cell converter 50 to the internal side circuit 62. . At this time, the power supplied to the internal circuit 62 is transformed by the transformer 63 and then supplied to the external AC load through the external circuit 61.

  The control device 100 includes a central processing unit (CPU) that is an arithmetic processing unit, a read only memory (ROM) that is a storage element that stores programs used by the CPU, arithmetic parameters, and the like. It is comprised by RAM (Random Access Memory) etc. which are memory elements to store temporarily.

  Further, the control device 100 communicates with each device provided in the power supply system 1. Communication between the control device 100 and each device is realized, for example, using CAN (Controller Area Network) communication. For example, the control device 100 communicates with the fuel cell 20, the inverter 31, the fuel cell converter 50, and the battery management device 11. The functions of the control device 100 according to the present embodiment may be divided by a plurality of control devices, and in this case, the plurality of control devices may be connected to each other via a communication bus such as CAN.

  For example, the control device 100 controls the output of the fuel cell 20 by controlling the supply amount of hydrogen gas and oxygen gas to the fuel cell 20. Further, for example, the control device 100 controls the conversion of power by the inverter 31 by controlling the operation of the switching element of the inverter 31. Thereby, generation of power by the driving motor 32 and regenerative power generation are controlled. Further, for example, the control device 100 controls the conversion of power by the chopper circuits 51 and 52 by controlling the operation of the switching elements of the pair of chopper circuits 51 and 52 of the fuel cell converter 50. Further, for example, the control device 100 controls the operation of the switching unit 59 of the fuel cell converter 50 to connect the fuel cell converter 50 to the positive electrode side of the fuel cell 20, and the fuel cell converter 50 is externally connected. It controls switching with the state connected to the unit 60. Thus, control device 100 controls the operation of fuel cell converter 50.

<2. Power supply system operation>
Subsequently, the operation of the power supply system 1 according to the present embodiment will be described with reference to FIGS.

  The operation of each device of the power supply system 1 is controlled by the control device 100 according to the driving state of the electric vehicle. Below, each operation | movement of such a power supply system 1 is demonstrated.

(During driving)
First, with reference to FIG. 2 and FIG. 3, an operation of the power supply system 1 when the electric powered vehicle travels will be described. FIG. 2 is a schematic view showing the flow of electric power in the power supply system 1 when the electric powered vehicle travels. FIG. 3 is a diagram for describing the operation of fuel cell converter 50 when the electric vehicle is traveling. In the drawings showing the flow of power in the power supply system of FIG. 2 etc. referred to in the present specification, the flow of power is indicated by thick arrows.

  At the time of traveling of the electric vehicle, control device 100 uses power stored in battery 10 mainly to drive drive motor 32 and uses generated power of fuel cell 20 to charge battery 10 and the like. Control system 1

  The control device 100 connects the fuel cell converter 50 to the positive electrode side of the fuel cell 20 by controlling the operation of the switching unit 59 when the electric vehicle is traveling. Thereby, specifically, as shown in FIG. 2, chopper circuits 51 and 52 of fuel cell converter 50 are connected to the positive electrode side of fuel cell 20 by switches 591 and 592.

  The control device 100 controls the output of the drive motor 32 based on parameters such as the acceleration / deceleration command amount and the vehicle speed so that, for example, the output of the drive motor 32 matches the required value when the electric vehicle travels. . At this time, as shown in FIG. 2, the control device 100 supplies the storage power of the battery 10 to the driving motor 32 through the inverter 31 by controlling the operation of the inverter 31.

  As shown in FIG. 2, the control device 100 connects the fuel cell converter 50 to the positive electrode side of the fuel cell 20 by the switching unit 59 when the electric vehicle is traveling, so that the generated power of the fuel cell 20 is on the load 30 side. Can be supplied to the fuel cell via the fuel cell converter 50. As a result, charging of the battery 10 using the generated power of the fuel cell 20 and feeding of the generated power of the fuel cell 20 to the driving motor 32 are realized.

  For example, when the remaining capacity SOC of the battery 10 is equal to or less than the threshold value, the control device 100 supplies the generated power of the fuel cell 20 to the battery 10 via the fuel cell converter 50 in order to charge the battery 10. The threshold value is set to, for example, a value that can appropriately determine whether the traveling of the electric-powered vehicle can be continued without the remaining capacity SOC of the battery 10 decreasing and the power being exhausted. Further, for example, when the output of the battery 10 is insufficient for the required value during traveling of the electrically powered vehicle, the control device 100 sends the generated power of the fuel cell 20 to the inverter 31 to supply power to the drive motor 32. The fuel is supplied via the fuel cell converter 50.

  As described above, when the generated power of the fuel cell 20 is supplied to the load 30 side, the control device 100 boosts the generated power of the fuel cell 20 by the fuel cell converter 50 and supplies the generated power to the load 30 side. Specifically, control device 100 boosts the generated power of fuel cell 20 by switching the lower switching elements 512 and 522 of chopper circuits 51 and 52 of fuel cell converter 50. Such operation of the fuel cell converter 50 is also referred to as step-up operation.

  For example, when boosting operation of fuel cell converter 50, control device 100 generates a triangular carrier wave, and compares the carrier wave with the voltage command value to open / close timing of lower switching elements 512, 522. Generates a pulse-like command signal indicating. Then, the control device 100 outputs a command signal to the fuel cell converter 50 to cause the lower switching elements 512 and 522 to perform switching operation according to the command signal.

  As described above, since the command signals of the lower switching elements 512 and 522 are determined according to the set value of the voltage command value to be compared with the carrier wave, the control device 100 sets the voltage command value appropriately. The duty ratio of the switching operation of the lower switching elements 512 and 522 can be controlled. Here, assuming that the voltage before boosting (the voltage of the power generated by the fuel cell 20) is V_in and the voltage after boosting (the voltage closer to the load 30 than the fuel cell converter 50) is V_out, the duty ratio γ is It is represented by (1).

  For example, first, the control device 100 determines the duty ratio γ based on the equation (1) so as to obtain a desired boost ratio. Then, control device 100 sets the voltage command value such that duty ratio γ becomes the value thus determined. Thereby, the boosting ratio in the boosting operation of fuel cell converter 50 is appropriately controlled.

  When boosting operation of fuel cell converter 50, control device 100 may switch lower switching elements 512 and 522 so that a phase difference occurs between them.

  In this case, for example, as shown in FIG. 3, the control device 100 generates carrier waves of the lower switching elements 512 and 522 so as to cause a phase difference of 180 °. Then, for each of lower switching elements 512 and 522, control device 100 generates a command signal to be turned on in a section where the carrier wave is equal to or higher than the voltage command value. Thereby, the command signals of the lower switching elements 512 and 522 can be generated so as to cause a phase difference of 180 ° to each other, so that the lower switching elements 512 and 522 are switched to perform a phase difference of 180 ° to each other. be able to. Therefore, a phase difference of 180 ° occurs between current iu flowing through reactor 515 and current iv flowing through reactor 525. Therefore, the cycle of the current i (in other words, the current obtained by combining the current iu and the current iv) flowing to the fuel cell 20 is halved compared to the case where the switching operations of the lower switching elements 512 and 522 have the same phase. Ru. Therefore, the amplitude of the current i corresponding to the pulsating current ripple can be reduced due to the switching operation of the lower switching elements 512 and 522.

  The phase difference between the carrier waves of lower switching elements 512 and 522 generated by control device 100 may be other than 180 °. Even in that case, the command signals of the lower switching elements 512 and 522 can be generated so as to cause a phase difference with each other. Therefore, a phase difference can be generated between the current iu and the current iv. Therefore, since the low frequency component of the current i flowing to the fuel cell 20 can be weakened, the amplitude of the current i corresponding to the pulsating current ripple due to the switching operation of the lower switching elements 512 and 522 can be reduced. .

(When charging externally)
Next, the operation of the power supply system 1 at the time of external charging of the battery 10 will be described with reference to FIGS. 4 and 5. The external charging of the battery 10 corresponds to charging of the battery 10 using the power received from the external AC power supply 201. FIG. 4 is a schematic view showing the flow of power in the power supply system 1 when the battery 10 is externally charged. FIG. 5 is a diagram for describing the operation of fuel cell converter 50 at the time of external charging of battery 10.

  When the electrically powered vehicle is stopped, the external AC power supply 201 may be connected to the external connection unit 60. In such a case, control device 100 controls power supply system 1 such that battery 10 is charged using the power received from external AC power supply 201 through external connection unit 60.

  When external connection unit 60 is connected to external AC power supply 201, control device 100 connects fuel cell converter 50 to external connection unit 60 by controlling the operation of switching unit 59. Thus, specifically, chopper circuits 51 and 52 of fuel cell converter 50 are connected to external connection unit 60 by switches 591 and 592 as shown in FIG.

  When external connection unit 60 is connected to external AC power supply 201, control device 100 is connected to external connection unit 60 by switching unit 59, as shown in FIG. Power received from the AC power supply 201 through the external connection unit 60 can be supplied to the load 30 through the fuel cell converter 50. Thereby, charging of battery 10 using the power received from external AC power supply 201 through external connection unit 60 can be realized.

  As described above, when the power received from the external AC power supply 201 is supplied to the load 30 side, the control device 100 rectifies the power received from the external AC power supply 201 by the fuel cell converter 50 to the load 30 side. Supply to Specifically, control device 100 causes power to be received from external AC power supply 201 by switching upper switching elements 511 and 521 and lower switching elements 512 and 522 of chopper circuits 51 and 52 of fuel cell converter 50. Rectify Such operation of the fuel cell converter 50 is also referred to as rectification operation.

  When rectifying operation of fuel cell converter 50, control device 100 causes, for example, fuel cell converter 50 to operate as a PWM rectifier. The PWM rectifier converts AC power to DC power using PWM control.

  In this case, for example, as shown in FIG. 5, the control device 100 generates a triangular carrier wave and an inverted carrier wave having a phase difference of 180 ° with respect to the carrier wave. Then, control device 100 generates a sinusoidal signal wave having the same frequency as voltage Vs on the input side (external connection unit 60 side) of reactors 515 and 525. The phase of the signal is appropriately set such that a desired phase can be obtained as the phase of the current is on the input side (external connection unit 60 side) of reactors 515 and 525 described later. Further, the amplitude of the signal is appropriately set such that a desired voltage can be obtained as the voltage Vo closer to the load 30 than the fuel cell converter 50.

  Then, the control device 100 generates a command signal for each of the upper switching elements 511 and 521 and the lower switching elements 512 and 522 by comparing the carrier wave and the inverted carrier wave with the signal wave. The control device 100 outputs the generated command signal to the fuel cell converter 50 to cause each switching element to perform a switching operation according to the command signal.

  For example, the control device 100 generates a command signal such that the upper switching element 511 is turned on in a section where the carrier wave is smaller than the signal wave. Further, the control device 100 generates a command signal such that the lower switching element 512 is turned on in a section where the carrier wave is equal to or greater than the signal wave. Further, the control device 100 generates a command signal such that the upper switching element 521 is turned on in a section where the inversion carrier wave is equal to or larger than the signal wave. Further, the control device 100 generates a command signal such that the lower switching element 522 is turned on in a section where the inverted carrier wave is smaller than the signal wave.

  As shown in FIG. 5, the command signal of each switching element generated as described above sequentially switches combinations of two switching elements turned on among the upper switching elements 511 and 521 and the lower switching elements 512 and 522. It becomes such a signal. As each switching element performs a switching operation according to such a command signal, there is a state in which magnetic energy is accumulated in reactors 515 and 525 and a state in which magnetic energy is released from reactors 515 and 525 to the load 30 side. Continue to be repeated alternately. As a result, the AC power received from the external AC power supply 201 is rectified to a DC current by the fuel cell converter 50 and supplied to the load 30 side. Therefore, battery 10 can be charged using the power received from external AC power supply 201 via external connection unit 60.

  It should be noted that in the command signal not hatched in FIG. 5, no current flows in the switching element turned on in response to the command signal, and current flows in the diode connected in parallel with the switching element Is shown.

  Here, as shown in FIG. 5, voltage Vc at the output side (connection point P51 side) of reactors 515 and 525 takes a value of Vo, 0 or -Vo, and the average value of voltage Vc is in phase with the signal wave It becomes sinusoidal. In addition, the current is at the input side (external connection unit 60 side) of the reactors 515 and 525 has a sine wave having a phase substantially matching the voltage Vs. Since the phase of the current is depends on the phase of the signal wave, the phase of the current is can be controlled by appropriately determining the phase of the signal wave. For example, as shown in FIG. 5, the control device 100 controls the phase of the current is to substantially coincide with the voltage Vs. Thereby, the power factor in the rectification operation of fuel cell converter 50 can be improved.

  As described above, when external connection unit 60 is connected to external AC power supply 201, control device 100 causes fuel cell converter 50 to be connected to external connection unit 60, and for example, fuel cell converter 50 serves as a PWM rectifier. By operating, the battery 10 can be charged using the power received from the external AC power supply 201 via the external connection unit 60.

  The upper switching elements 511 and 521 may be omitted from the configuration of the power supply system 1. In that case, when external connection unit 60 is connected to external AC power supply 201, control device 100 connects fuel cell converter 50 to external connection unit 60, and for example, fuel cell converter 50 serves as a diode bridge. By operating it, the AC power received from the external AC power supply 201 can be rectified to a DC current and supplied from the fuel cell converter 50 to the load 30 side. Therefore, battery 10 can be charged using the power received from external AC power supply 201 via external connection unit 60. Specifically, when the fuel cell converter 50 is operated as a diode bridge, the control device 100 maintains the lower switching elements 512 and 522 OFF.

  Also, in the above, an example was described in which the power received from the external AC power supply 201 via the external connection unit 60 is used to charge the battery 10 when the external connection unit 60 is connected to the external AC power supply 201. The power received from the external AC power supply 201 may be supplied to the drive motor 32. For example, when external connection unit 60 is connected to external AC power supply 201, control device 100 makes a request for driving drive motor 32, for example, as indicated by the double-dotted line arrow in FIG. The power received from the external AC power supply 201 through the external connection unit 60 may be supplied to the driving motor 32 through the inverter 31.

(At the time of external power feeding)
Next, the operation of the power supply system 1 at the time of external power feeding to the external AC load 202 will be described with reference to FIGS. 6 and 7. In the present embodiment, external power feeding to the external AC load 202 corresponds to power feeding to the external AC load 202 using the stored power of the battery 10. FIG. 6 is a schematic view showing the flow of power in the power supply system 1 at the time of external power feeding to the external AC load 202 using the stored power of the battery 10. FIG. 7 is a diagram for describing the operation of fuel cell converter 50 at the time of external power feeding to external AC load 202 using the storage power of battery 10.

  When the electric powered vehicle is stopped, the external AC load 202 may be connected to the external connection unit 60. In such a case, control device 100 controls power supply system 1 such that the stored power of battery 10 is supplied to external AC load 202 via external connection unit 60.

  When external connection unit 60 is connected to external AC load 202, control device 100 connects fuel cell converter 50 to external connection unit 60 by controlling the operation of switching unit 59. Thus, specifically, as shown in FIG. 6, chopper circuits 51 and 52 of fuel cell converter 50 are connected to external connection unit 60 by switches 591 and 592.

  When external connection unit 60 is connected to external AC load 202, control device 100 causes fuel cell converter 50 to be connected to external connection unit 60 by switching unit 59, as shown in FIG. The stored power of 10 can be supplied to the external connection unit 60 side through the fuel cell converter 50. Thereby, it can be realized that the stored power of the battery 10 is supplied to the external AC load 202 via the external connection unit 60.

  As described above, when the storage power of the battery 10 is supplied to the external connection unit 60 side, the control device 100 converts the storage power of the battery 10 into an alternating current by the fuel cell converter 50 to the external connection unit 60 side. Supply. Specifically, control device 100 performs switching operation of upper switching elements 511 and 521 and lower switching elements 512 and 522 of chopper circuits 51 and 52 of fuel cell converter 50 to convert the stored power of battery 10 to alternating current. To convert. Such operation of the fuel cell converter 50 is also referred to as direct current to alternating current conversion operation.

  The control device 100 operates, for example, the fuel cell converter 50 as a PWM inverter when the fuel cell converter 50 performs the DC / AC conversion operation. The PWM inverter converts DC power into AC power using PWM control.

  In this case, for example, as shown in FIG. 7, the control device 100 generates a triangular carrier wave and an inverted carrier wave having a phase difference of 180 ° with respect to the carrier wave. Then, control device 100 generates a sinusoidal signal wave having the same frequency as the target value of voltage Vs on the output side (external connection unit 60 side) of reactors 515 and 525. The phase of the signal is appropriately set such that a desired phase can be obtained as the phase of the current is on the output side (external connection unit 60 side) of reactors 515 and 525 described later. Further, the amplitude of the signal is appropriately set such that the amplitude of the voltage Vs approaches the target value.

  Then, the control device 100 generates a command signal for each of the upper switching elements 511 and 521 and the lower switching elements 512 and 522 by comparing the carrier wave and the inverted carrier wave with the signal wave. The control device 100 outputs the generated command signal to the fuel cell converter 50 to cause each switching element to perform a switching operation according to the command signal.

  For example, the control device 100 generates a command signal such that the upper switching element 511 is turned on in a section where the carrier wave is smaller than the signal wave. Further, the control device 100 generates a command signal such that the lower switching element 512 is turned on in a section where the carrier wave is equal to or greater than the signal wave. Further, the control device 100 generates a command signal such that the upper switching element 521 is turned on in a section where the inversion carrier wave is equal to or larger than the signal wave. Further, the control device 100 generates a command signal such that the lower switching element 522 is turned on in a section where the inverted carrier wave is smaller than the signal wave.

  As shown in FIG. 7, the command signal of each switching element generated as described above sequentially switches combinations of two switching elements turned on among the upper switching elements 511 and 521 and the lower switching elements 512 and 522. It becomes such a signal. A state in which magnetic energy is stored in reactors 515 and 525 and a state in which magnetic energy is released from reactors 515 and 525 to external connection unit 60 by each switching element performing a switching operation according to such a command signal And continue to be repeated alternately. Thereby, the stored power of the battery 10 is converted into an alternating current by the fuel cell converter 50 and supplied to the external connection portion 60 side. Therefore, the storage power of the battery 10 can be supplied to the external AC load 202 via the external connection unit 60. At this time, the voltage Vs after direct current to alternating current conversion by the fuel cell converter 50 substantially matches the target value.

  It should be noted that in the command signal not hatched in FIG. 7, no current flows in the switching element turned on in response to the command signal, and current flows in the diode connected in parallel with the switching element Is shown.

  Here, as shown in FIG. 7, voltage Vc at the input side (connection point P51 side) of reactors 515, 525 takes voltage Vo, 0 or -Vo on the side of load 30 from fuel cell converter 50, and voltage Vc The average value of is sinusoidal in phase with the signal wave. In addition, the current is at the output side (external connection unit 60 side) of the reactors 515 and 525 has a sine wave shape having a phase difference of approximately 180 ° with respect to the voltage Vs. Since the phase of the current is depends on the phase of the signal wave, the phase of the current is can be controlled by appropriately determining the phase of the signal wave. For example, as shown in FIG. 7, the control device 100 controls the phase of the current is so that a phase difference of approximately 180 ° with respect to the voltage Vs occurs. Thus, the power factor in the direct current to alternating current conversion operation of fuel cell converter 50 can be improved.

  As described above, when the external connection unit 60 is connected to the external AC load 202, the control device 100 connects the fuel cell converter 50 to the external connection unit 60. For example, the fuel cell converter 50 is used as a PWM inverter. By operating, the stored power of the battery 10 can be supplied to the external AC load 202 via the external connection portion 60.

  In the above, when the external connection unit 60 is connected to the external AC load 202, the example has been described in which the stored power of the battery 10 is converted to an AC current by the fuel cell converter 50 and the power is supplied to the external AC load 202. However, the power regenerated by the load 30 may be supplied to the external AC load 202. For example, when the load 30 can execute regenerative power generation in a state where the external connection unit 60 is connected to the external AC load 202, for example, the control device 100 loads the load as indicated by the dashed double-dotted arrow in FIG. The power regenerated by the power generation 30 may be converted into an alternating current by the fuel cell converter 50 and may be supplied to the external AC load 202.

<3. Power system effect>
Then, the effect of power supply system 1 concerning this embodiment is explained.

  In the power supply system 1 according to the present embodiment, the fuel cell converter 50 is a reactor whose one end is connected to the positive electrode side of the fuel cell 20, and an upper diode connected between the other end of the reactor and the positive electrode side of the load 30. A pair of chopper circuits 51 and 52 provided in parallel, each including a lower diode connected between the other end of the reactor and the negative electrode side of the fuel cell 20 and a lower switching element connected in parallel to the lower diode; Prepare. Further, the fuel cell converter 50 is connected to the positive electrode side of the fuel cell 20 on the fuel cell 20 side from the connection points P51 and P52 of the upper diode, the lower diode and the reactor in the pair of chopper circuits 51 and 52 of the fuel cell converter 50. A switching unit 59 is provided which can switch between the closed state and the state in which the fuel cell converter 50 is connected to the external connection unit 60.

  As a result, when the external AC power supply 201 is connected to the external connection unit 60, the fuel cell converter 50 is connected to the external connection unit 60 and is rectified, whereby the external AC power supply 201 is connected via the external connection unit 60. The power received can be used to charge the battery 10. Therefore, the fuel cell converter 50 can be used to convert the electric power in the external charging of the battery 10 when, for example, the electric vehicle stops driving the drive motor 32. Therefore, it is possible to suppress the occurrence of a situation where the fuel cell converter 50 is not used when the electrically powered vehicle is stopped or the like. Therefore, the utilization efficiency of the device in the power supply system 1 including the battery 10 and the fuel cell 20 can be improved.

  Furthermore, according to the present embodiment, by improving the utilization efficiency of the device in the power supply system 1, it is possible to suppress an increase in the number of parts in the power supply system 1. For example, suppressing additional provision of a device for performing conversion of power in external charging of battery 10 (specifically, rectification of DC power received from external AC power supply 201) to power supply system 1 it can. Therefore, an increase in the size of the power supply system 1 can be suppressed.

  Further, in the power supply system 1 according to the present embodiment, in each of the pair of chopper circuits 51 and 52 of the fuel cell converter 50, the upper switching element may be connected in parallel to the upper diode. Thereby, when external AC load 202 is connected to external connection portion 60, electric power stored in battery 10 is converted to external AC load 202 by connecting fuel cell converter 50 to external connection portion 60 and performing DC / AC conversion operation. Can be fed via the external connection 60. Therefore, fuel cell converter 50 can be used for conversion of electric power in external power supply to external AC load 202 when the electric vehicle is stopped or the like. Therefore, the utilization efficiency of the device in the power supply system 1 can be more effectively improved.

  Further, in the power supply system 1 according to the present embodiment, the control device 100 operates as a PWM rectifier by connecting the fuel cell converter 50 to the external connection unit 60 when the external connection unit 60 is connected to the external AC power supply 201. Thus, the battery 10 can be charged using the power received from the external AC power supply 201 via the external connection unit 60. As a result, while improving the power factor in the rectification operation of fuel cell converter 50, battery 10 can be charged using the power received from external AC power supply 201.

  Further, in the power supply system 1 according to the present embodiment, the control device 100 operates as a PWM inverter by connecting the fuel cell converter 50 to the external connection unit 60 when the external connection unit 60 is connected to the external AC load 202. Thus, the stored power of the battery 10 can be supplied to the external AC load 202 via the external connection portion 60. Thus, the stored power of the battery 10 can be supplied to the external AC load 202 while improving the power factor in the DC-AC conversion operation of the fuel cell converter 50.

  Further, in the power supply system 1 according to the present embodiment, the control device 100 causes the lower switching elements 512, 522 of the pair of chopper circuits 51, 52 of the fuel cell converter 50 to mutually The switching operation can be performed so that a phase difference occurs. Thereby, a phase difference can be generated between the current flowing through reactor 515 and the current flowing through reactor 525, so that the pulsating current ripple due to the switching operation of lower switching elements 512 and 522 can be reduced. it can.

<4. Modified example>
Subsequently, a power supply system according to a modification will be described with reference to FIGS. 8 and 9.

[First Modification]
First, a power supply system 1a according to a first modification will be described with reference to FIG. FIG. 8 is a schematic view showing a schematic configuration of a power supply system 1a according to a first modification.

  The power supply system 1a according to the first modification differs from the power supply system 1 described above in the installation position of the switching unit 59 in the chopper circuits 51 and 52 of the fuel cell converter.

  In the fuel cell converter 50a according to the first modification, the switching unit 59 includes a switch 591 provided in the chopper circuit 51 and a switch 592 provided in the chopper circuit 52, as in the power supply system 1 described above.

  As shown in FIG. 8, in the first modification, the switch 591 is provided between a connection point P51 of the upper diode 513, the lower diode 514, and the reactor 515, and the reactor 515. The switch 591 connects and disconnects the chopper circuit 51 and the positive electrode side of the fuel cell 20 at such an installation position. Further, the switch 591 can connect the chopper circuit 51 to one of the pole sides of the external connection portion 60 at such an installation position, and the chopper circuit 51 is connected to the positive electrode side of the fuel cell 20; It is possible to switch between the state where the circuit 51 is connected to one of the pole sides of the external connection portion 60.

  Further, as shown in FIG. 8, in the first modification, the switch 592 is provided between a connection point P52 of the upper diode 523 and the lower diode 524 and the reactor 525 and the reactor 525. Switch 592 connects chopper circuit 52 with the positive electrode side of fuel cell 20 at such an installation position. The switch 592 can connect the chopper circuit 51 to the other pole side of the external connection portion 60 at such an installation position, and the chopper circuit 52 is connected to the positive electrode side of the fuel cell 20; It is possible to switch between the state where the circuit 52 is connected to the other pole side of the external connection 60.

  In the first modification, the installation position of the switching unit 59 in the fuel cell converter 50a is as described above. Therefore, when the fuel cell converter 50a is connected to the external connection unit 60 by the switching unit 59, the external Reactors 515 and 525 are not included in the circuit formed by the inner side circuit 62 of the connection portion 60 and the fuel cell converter 50a.

  Here, specifically, the transformer 63 of the external connection portion 60 includes a coil wound around a part of the external circuit 61 and a coil wound around a part of the inner circuit 62. Some of the coils of such a transformer 63 do not contribute to the transformation, resulting in leakage inductance. Therefore, in the first modification, when the fuel cell converter 50a is connected to the external connection portion 60, in the circuit formed by the internal side circuit 62 of the external connection portion 60 and the fuel cell converter 50a, the internal side of the transformer 63 A part of the coils on the circuit 62 side can function as a reactor.

  Therefore, when the external AC power supply 201 is connected to the external connection unit 60, the fuel cell converter 50a is connected to the external connection unit 60, and the fuel cell converter 50a is rectified as in the power supply system 1 described above. Can. Further, when the external AC load 202 is connected to the external connection portion 60, the fuel cell converter 50a is connected to the external connection portion 60, and the fuel cell converter 50a is subjected to DC / AC conversion operation as in the power supply system 1 described above. It can be done.

  As described above, if the installation position of the switching unit 59 in the chopper circuit 51, 52 of the fuel cell converter is closer to the fuel cell 20 than the connection point P51, P52 of the upper diode, lower diode and reactor in the chopper circuit 51, 52 Well, not particularly limited.

Second Modified Example
Next, a power supply system 1b according to a second modification will be described with reference to FIG. FIG. 9 is a schematic view showing a schematic configuration of a power supply system 1b according to a second modification.

  The power supply system 1b according to the second modification differs from the above-described power supply system 1 in the number of chopper circuits provided in the fuel cell converter.

  As shown in FIG. 9, a fuel cell converter 50b according to the second modification further includes chopper circuits 53 and 54 in addition to the chopper circuits 51 and 52 described above. The four chopper circuits 51, 52, 53, 54 of the fuel cell converter 50b are provided in parallel to one another. The chopper circuits 53 and 54 are connected to, for example, the chopper circuit 51, the chopper circuit 52, and the connection point P59 on the positive electrode side of the fuel cell 20.

  The chopper circuits 53 and 54 include upper switching elements 531 and 541, lower switching elements 532 and 542, upper diodes 533 and 543, lower diodes 534 and 544, and reactors 535 and 545. One end of the reactors 535 and 545 is connected to the positive electrode side of the fuel cell 20. The upper diodes 533 and 543 are diodes connected between the other ends of the reactors 535 and 545 and the positive electrode side of the inverter 31. Specifically, upper diodes 533 and 543 regulate the direction of the current in one direction from the other end of reactors 535 and 545 toward the positive electrode side of inverter 31. The lower diodes 534 and 544 are diodes connected between the other ends of the reactors 535 and 545 and the negative electrode side of the fuel cell 20. Specifically, lower diodes 534 and 544 regulate the direction of current in one direction from the negative electrode side of fuel cell 20 to the other end of reactors 535 and 545. The upper switching elements 531 and 541 are switching elements connected in parallel to the upper diodes 533 and 543. The lower switching elements 532 and 542 are switching elements connected in parallel to the lower diodes 534 and 544.

  Further, from the connection points P51, P52, P53, P54 of the upper diode, lower diode and reactor in the chopper circuits 51, 52, 53, 54 of the fuel cell converter 50b according to the second modification, the fuel cell 20 side A switching unit 59 b is provided to connect and disconnect the cell converter 50 b and the positive electrode side of the fuel cell 20. Similar to the switching unit 59 described above, the switching unit 59b can switch between the state in which the fuel cell converter 50b is connected to the positive electrode side of the fuel cell 20 and the state in which the fuel cell converter 50b is connected to the external connection unit 60b. It is.

  Here, as shown in FIG. 9, the external connection unit 60b according to the second modification differs from the external connection unit 60 described above in that two internal sides are connected to one external circuit 61b via a transformer 63b. Circuits 62b and 62b are provided. Each of the inner circuits 62b, 62b has a pair of poles.

  As shown in FIG. 9, the switching unit 59 b according to the second modification further includes switches 593 and 594 in addition to the switches 591 and 592 described above. Switches 593 and 594 are provided, for example, between connection point P59 and reactors 535 and 545.

  Switch 591 is able to connect chopper circuit 51 and one pole side of one internal circuit 62b of external connection portion 60b at the installation position, and switch 592 has chopper circuit 52 and external connection portion 60b at the installation position. The other pole side of one internal circuit 62b can be connected. Therefore, the switches 591 and 592 are in a state in which the chopper circuits 51 and 52 are connected to the positive electrode side of the fuel cell 20 and a state in which the chopper circuits 51 and 52 are connected to one internal circuit 62b of the external connection portion 60b. Can be switched.

  The switch 593 can connect the chopper circuit 53 and one pole side of the other internal circuit 62b of the external connection portion 60b at the installation position, and the switch 594 can connect the chopper circuit 54 and the external connection portion at the installation position. The other pole side of the other internal circuit 62b of 60b can be connected. Therefore, in the switches 593 and 594, the chopper circuits 53 and 54 are connected to the positive electrode side of the fuel cell 20, and the chopper circuits 53 and 54 are connected to the other internal circuit 62b of the external connection portion 60b. Can be switched.

  A state in which the chopper circuits 51 and 52 are connected to the positive electrode side of the fuel cell 20 by the switches 591 and 592 and the chopper circuits 53 and 54 are connected to the positive electrode side of the fuel cell 20 by the switches 593 and 594 is a fuel cell converter 50b corresponds to a state in which the positive electrode side of the fuel cell 20 is connected. On the other hand, chopper circuits 51 and 52 are connected to one internal circuit 62b of external connection unit 60b by switches 591 and 592, and chopper circuits 53 and 54 are connected to the other internal side of external connection unit 60b by switches 593 and 594. The state in which the fuel cell converter 50b is connected to the circuit 62b corresponds to the state in which the fuel cell converter 50b is connected to the external connection portion 60b.

  In the second modification, when the external AC power supply 201 is connected to the external connection unit 60b, the fuel cell converter 50b is connected to the external connection unit 60b. For example, the chopper circuits 53 and 54 are chopper circuits 51 and 52, respectively. The fuel cell converter 50b can be rectified by operating in the same manner as the operation described above. Further, when the external AC load 202 is connected to the external connection portion 60b, the fuel cell converter 50b is connected to the external connection portion 60b, and for example, the chopper circuits 53 and 54 operate as described above for the chopper circuits 51 and 52 By operating similarly, the fuel cell converter 50b can perform DC / AC conversion operation.

  Further, in the second modification, as in the power supply system 1 described above, the control device 100 lowers the switching elements 512, 522, when the fuel cell converter 50b is operated for boosting, for example, when the electric vehicle is traveling. The switches 532 and 542 may be switched to generate a phase difference.

  In this case, for example, the control device 100 generates carrier waves of the lower switching elements 512, 522, 532, and 542 so that a phase difference of 90 ° occurs with each other. Then, control device 100 generates a command signal such that each of lower switching elements 512, 522, 532 and 542 is turned on in a section where the carrier wave is equal to or higher than the voltage command value. As a result, the command signals of the lower switching elements 512, 522, 532, 542 are generated so that a phase difference of 90 ° occurs with each other, so that the lower switching elements 512, 522, 532, 542 are 90 ° with each other. A switching operation can be made to occur. Therefore, a 90 ° phase difference occurs between the currents flowing through reactors 515, 525, 535, 545. Therefore, the period of the current flowing through the fuel cell 20 is one fourth of that in the case where the switching operations of the lower switching elements 512, 522, 532, 542 have the same phase. Therefore, the amplitude of the current flowing through the fuel cell 20 corresponding to the pulsating current ripple due to the switching operation of the lower switching elements 512, 522, 532, 542 can be reduced more effectively.

  As described above, the number of chopper circuits provided in the fuel cell converter and having the above-described switching unit may be at least two, and is not particularly limited.

<5. Application example>
Subsequently, a power supply system 2 according to the application example will be described with reference to FIGS. 10 to 14.

[Constitution]
First, the configuration of the power supply system 2 according to the application example will be described with reference to FIG. FIG. 10 is a schematic view showing a schematic configuration of a power supply system 2 according to an application example.

  As shown in FIG. 10, the power supply system 2 according to the application example further includes a battery converter 40 as compared to the power supply system 1 described above.

  In the application example, as shown in FIG. 10, the battery 10 is connected to the inverter 31 in parallel with the fuel cell 20 and the fuel cell converter 50 via the battery converter 40 capable of converting a voltage. Therefore, the storage power of the battery 10 can be supplied to the inverter 31 via the battery converter 40. The stored power of the battery 10 may be supplied to various auxiliary devices provided in the motor-driven vehicle. Further, the power supplied from the load 30 can be supplied to the battery 10 through the battery converter 40.

  The battery converter 40 is a power converter capable of converting a voltage, and has a function of boosting the stored power of the battery 10 and supplying it to the load 30 side. Furthermore, the battery converter 40 has a function of stepping down the power supplied from the load 30 and supplying the power to the battery 10. The battery converter 40 is provided with a switching element, and by controlling the operation of the switching element, conversion of power by the battery converter 40 is controlled.

  As shown in FIG. 10, the battery converter 40 includes a pair of chopper circuits 41 and 42 provided in parallel to each other.

  The chopper circuit 41 includes an upper switching element 411, a lower switching element 412, an upper diode 413, a lower diode 414, and a reactor 415. One end of a reactor 415 is connected to the positive electrode side of the battery 10. The upper diode 413 is a diode connected between the other end of the reactor 415 and the positive electrode side of the inverter 31. Specifically, the upper diode 413 regulates the direction of current in one direction from the other end of the reactor 415 toward the positive electrode side of the inverter 31. The lower diode 414 is a diode connected between the other end of the reactor 415 and the negative electrode side of the battery 10. Specifically, lower diode 414 regulates the direction of the current in one direction from the negative electrode side of battery 10 to the other end of reactor 415. The upper switching element 411 is a switching element connected in parallel to the upper diode 413. The lower switching element 412 is a switching element connected in parallel to the lower diode 414.

  The chopper circuit 42 includes an upper switching element 421, a lower switching element 422, an upper diode 423, a lower diode 424, and a reactor 425. One end of a reactor 425 is connected to the positive electrode side of the battery 10. The upper diode 423 is a diode connected between the other end of the reactor 425 and the positive electrode side of the inverter 31. Specifically, the upper diode 423 regulates the direction of the current in one direction from the other end of the reactor 425 to the positive electrode side of the inverter 31. The lower diode 424 is a diode connected between the other end of the reactor 425 and the negative electrode side of the battery 10. Specifically, lower diode 424 regulates the direction of the current in one direction from the negative electrode side of battery 10 to the other end of reactor 425. The upper switching element 421 is a switching element connected in parallel to the upper diode 423. The lower switching element 422 is a switching element connected in parallel to the lower diode 424.

  As each switching element of the chopper circuits 41 and 42, for example, a MOSFET (Metal Oxide Semiconductor Field Effect Transistor), an IGBT (Insulated Gate Bipolar Transistor) or the like is used.

  In each chopper circuit of battery converter 40, the lower switching element 412 (422) performs switching operation in a state where upper switching element 411 (421) is maintained OFF, whereby the stored power of battery 10 is boosted and the load It is supplied to the 30 side. At this time, in each chopper circuit of battery converter 40, magnetic energy is stored in reactor 415 (425) when lower switching element 412 (422) is ON, and when lower switching element 412 (422) is OFF. Magnetic energy is released from the reactor 415 (425).

  In each chopper circuit of battery converter 40, power is supplied from load 30 by upper switching element 411 (421) performing a switching operation while lower switching element 412 (422) is maintained OFF. Is stepped down and supplied to the battery 10. At this time, in each chopper circuit of battery converter 40, magnetic energy is stored in reactor 415 (425) when upper switching element 411 (421) is ON, and when upper switching element 411 (421) is OFF. Magnetic energy is released from the reactor 415 (425).

  Here, on the battery 10 side from the connection points P41 and P42 of the upper diode, the lower diode and the reactor in the pair of chopper circuits 41 and 42 of the battery converter 40, a switching portion for connecting and disconnecting the battery converter 40 and the positive electrode side of the battery 10 49 are provided. Switching unit 49 is capable of switching between a state in which battery converter 40 is connected to the positive electrode side of battery 10 and a state in which battery converter 40 is connected to external connection portion 60.

  As shown in FIG. 10, the switching unit 49 includes a switch 491 and a switch 492.

  The switch 491 is provided on the battery 10 side from the connection point P41 of the upper diode 413, the lower diode 414, and the reactor 415 in the chopper circuit 41, and connects the chopper circuit 41 and the positive electrode side of the battery 10 at the installation position. For example, the switch 491 is provided between the chopper circuit 41, the chopper circuit 42, and the connection point P49 on the positive electrode side of the battery 10 and the reactor 415. The switch 491 can connect the chopper circuit 41 to one of the pole sides of the external connection unit 60 at the installation position, and the chopper circuit 41 is connected to the positive electrode side of the battery 10; It is possible to switch to the state of being connected to one of the pole sides of the connection portion 60.

  The switch 492 is provided on the battery 10 side from the connection point P42 of the upper diode 423 and the lower diode 424 and the reactor 425 in the chopper circuit 42, and connects and connects the chopper circuit 42 and the positive electrode side of the battery 10 at the installation position. For example, the switch 492 is provided between the chopper circuit 41, the chopper circuit 42, and the connection point P49 on the positive electrode side of the battery 10 and the reactor 425. Further, switch 492 can connect chopper circuit 42 to the other pole side of external connection portion 60 at the installation position, and a state where chopper circuit 42 is connected to the positive pole side of battery 10, chopper circuit 42 is externally It is possible to switch to the state of being connected to the other pole side of the connection portion 60.

  When the chopper circuit 41 is connected to the positive side of the battery 10 by the switch 491 and the chopper circuit 42 is connected to the positive side of the battery 10 by the switch 492, the battery converter 40 is connected to the positive side of the battery 10 It corresponds to the state. On the other hand, battery converter 40 is in a state where chopper circuit 41 is connected to one pole side of external connection portion 60 by switch 491 and chopper circuit 42 is connected to the other pole side of external connection portion 60 by switch 492. Corresponds to the state of being connected to the external connection unit 60.

  The battery converter 40 can perform power conversion between the external connection unit 60 and the load 30 side in a state where the battery converter 40 is connected to the external connection unit 60. For example, the battery converter 40 can convert DC power supplied from the load 30 side into AC power and supply the AC power to the external connection unit 60. The power conversion by the battery converter 40 in the state where the battery converter 40 is connected to the external connection unit 60 will be described in detail later.

  In the application example, the control device 100 controls the conversion of power by the chopper circuits 41 and 42 by controlling the operation of the switching elements of the pair of chopper circuits 41 and 42 of the battery converter 40. Also, for example, the control device 100 controls the operation of the switching unit 49 of the battery converter 40 to connect the battery converter 40 to the positive electrode side of the battery 10 and connect the battery converter 40 to the external connection unit 60. Control the switching between the two states. Thus, control device 100 controls the operation of battery converter 40.

[Operation]
Subsequently, the operation of the power supply system 2 according to the application example will be described with reference to FIGS.

(During driving)
First, with reference to FIG. 11, the operation of the power supply system 2 when the electric powered vehicle travels will be described. FIG. 11 is a schematic view showing the flow of electric power in the power supply system 2 when the electric powered vehicle travels.

  At the time of traveling of the electric vehicle, control device 100 uses power stored in battery 10 mainly to drive drive motor 32 and uses generated power of fuel cell 20 to charge battery 10 and the like. Control system 2

  The control device 100 connects the fuel cell converter 50 to the positive electrode side of the fuel cell 20 by controlling the operation of the switching unit 59 when the electric vehicle is traveling. Thereby, specifically, chopper circuits 51 and 52 of fuel cell converter 50 are connected to the positive electrode side of fuel cell 20 by switches 591 and 592 as shown in FIG. Further, control device 100 connects battery converter 40 to the positive electrode side of battery 10 by controlling the operation of switching unit 49. Thereby, specifically, chopper circuits 41 and 42 of battery converter 40 are connected to the positive electrode side of battery 10 by switches 491 and 492 as shown in FIG.

  The control device 100 connects the fuel cell converter 50 to the positive electrode side of the fuel cell 20 by the switching unit 59 when the electric vehicle is traveling, thereby, as shown in FIG. Can be supplied to the fuel cell via the fuel cell converter 50. At this time, the control device 100 boosts the generated power of the fuel cell 20 by the fuel cell converter 50 and supplies it to the load 30 side. The boosting operation by the fuel cell converter 50 is the same as the boosting operation by the fuel cell converter 50 in the power supply system 1 described above, and thus the description thereof is omitted.

  The control device 100 controls the output of the drive motor 32 based on parameters such as the acceleration / deceleration command amount and the vehicle speed so that, for example, the output of the drive motor 32 matches the required value when the electric vehicle travels. . Here, when the electric powered vehicle is traveling, the control unit 100 connects the stored power of the battery 10 to the load 30 side as shown in FIG. 11 by the battery converter 40 being connected to the positive electrode side of the battery 10 by the switching unit 49. Can be supplied via the battery converter 40.

  As described above, when the storage power of the battery 10 is supplied to the load 30 side, the control device 100 boosts the storage power of the battery 10 by the battery converter 40 and supplies it to the load 30 side. Specifically, control device 100 boosts the stored power of battery 10 by switching the lower switching elements 412 and 422 of chopper circuits 41 and 42 of battery converter 40. Such operation of the battery converter 40 is also referred to as step-up operation.

  For example, when boosting operation of battery converter 40, control device 100 compares the triangular carrier wave with the voltage command value in the same manner as the boosting operation by fuel cell converter 50 in power supply system 1 described above. A pulse wave command signal indicating the open / close timing of the lower switching elements 412 and 422 is generated. Then, the control device 100 outputs a command signal to the battery converter 40 to cause the lower switching elements 412 and 422 to perform switching operation according to the command signal.

  In addition, for example, similarly to the boosting operation by the fuel cell converter 50 in the power supply system 1 described above, the control device 100 determines the duty ratio of the lower switching elements 412 and 422 so as to obtain a desired boost ratio. Then, control device 100 sets the voltage command value such that the duty ratio becomes the value thus determined. Thereby, the boosting ratio in the boosting operation of battery converter 40 is appropriately controlled.

  Further, when boosting operation of battery converter 40, control device 100 switches lower switching elements 412 and 422 so that a phase difference occurs between them similarly to the boosting operation by fuel cell converter 50 in power supply system 1 described above. You may operate it. For example, the control device 100 switches the lower switching elements 412 and 422 so that they have a phase difference of 180 ° by generating carrier waves of the lower switching elements 412 and 422 so as to cause a phase difference of 180 degrees. You may operate it. The phase difference between the carrier waves of lower switching elements 412 and 422 generated by control device 100 may be other than 180 °.

  The control device 100 is supplied from the load 30 side as shown by the two-dot chained arrow in FIG. 11 as the battery converter 40 is connected to the positive electrode side of the battery 10 by the switching unit 49 when the electric vehicle is traveling. Power can be supplied to the battery 10 via the battery converter 40. As a result, charging of the battery 10 using the power generated by the fuel cell 20 and charging of the battery 10 using regenerative power of the driving motor 32 are realized.

  As described above, when the power supplied from the load 30 side is supplied to the battery 10, the control device 100 reduces the power supplied from the load 30 side by the battery converter 40 and supplies the power to the battery 10. Specifically, control device 100 reduces the regenerative power of drive motor 32 by switching the upper switching elements 411 and 421 of chopper circuits 41 and 42 of battery converter 40. Such operation of the battery converter 40 is also referred to as step-down operation.

  For example, when step-down operation of battery converter 40 is performed, control device 100 compares the triangular carrier wave with the voltage command value in the same manner as the boosting operation by fuel cell converter 50 in power supply system 1 described above. A pulse wave command signal indicating the open / close timing of the upper switching elements 411 and 421 is generated. Then, the control device 100 causes the upper switching elements 411 and 421 to perform the switching operation according to the command signal by outputting the command signal to the battery converter 40.

  As described above, since the command signals of the upper switching elements 411 and 421 are determined according to the set value of the voltage command value to be compared with the carrier wave, the control device 100 sets the voltage command value appropriately. The duty ratio of the switching operation of the upper switching elements 411 and 421 can be controlled. Here, assuming that the voltage before voltage reduction (voltage on the load 30 side from the battery converter 40) is V_in and the voltage after voltage reduction (voltage on the battery 10 side from the battery converter 40) is V_out, the duty ratio γ is It is represented by (2).

  For example, the control device 100 first determines the duty ratio γ based on the equation (2) so as to obtain a desired step-down ratio. Then, control device 100 sets the voltage command value such that duty ratio γ becomes the value thus determined. Thereby, the step-down ratio in the step-down operation of battery converter 40 is appropriately controlled.

  Further, when step-down operation of battery converter 40 is performed, control device 100 switches upper switching elements 411 and 421 such that a phase difference occurs between them, similarly to the boosting operation by fuel cell converter 50 in power supply system 1 described above. You may operate it. For example, the control device 100 generates the carrier waves of the upper switching elements 411 and 421 so as to cause a 180 ° phase difference with each other, thereby switching the upper switching elements 411 and 421 so that a 180 ° phase difference with each other. You may operate it. The phase difference between the carrier waves of the upper switching elements 411 and 421 generated by the control device 100 may be other than 180 °.

(When charging externally)
Next, with reference to FIG. 12, the operation of the power supply system 2 at the time of external charging of the battery 10 will be described. FIG. 12 is a schematic view showing the flow of power in the power supply system 2 when the battery 10 is externally charged.

  When the electrically powered vehicle is stopped, the external AC power supply 201 may be connected to the external connection unit 60. In such a case, control device 100 controls power supply system 2 such that battery 10 is charged using the power received from external AC power supply 201 through external connection unit 60.

  When external connection unit 60 is connected to external AC power supply 201, control device 100 connects fuel cell converter 50 to external connection unit 60 by controlling the operation of switching unit 59. Thus, specifically, as shown in FIG. 12, chopper circuits 51 and 52 of fuel cell converter 50 are connected to external connection unit 60 by switches 591 and 592. Further, control device 100 connects battery converter 40 to the positive electrode side of battery 10 by controlling the operation of switching unit 49. Thereby, specifically, chopper circuits 41 and 42 of battery converter 40 are connected to the positive electrode side of battery 10 by switches 491 and 492 as shown in FIG.

  When external connection unit 60 is connected to external AC power supply 201, control device 100 connects fuel cell converter 50 to external connection unit 60 by switching unit 59, as shown in FIG. Power received from the AC power supply 201 through the external connection unit 60 can be supplied to the load 30 through the fuel cell converter 50. Thereby, battery 10 can be charged using the power received from external AC power supply 201. At this time, the control device 100 rectifies the power received from the external AC power supply 201 by the fuel cell converter 50 and supplies the rectified power to the load 30 side. The rectification operation by the fuel cell converter 50 is the same as the rectification operation by the fuel cell converter 50 in the power supply system 1 described above, and thus the description thereof is omitted.

  Here, in the case of charging the battery 10 using the power received from the external AC power supply 201, it is necessary to adjust the voltage of the power supplied to the battery 10 to a charging voltage which can be charged by the battery 10.

  Control device 100 can adjust the voltage of the power supplied to battery 10 by controlling the rectifying operation of fuel cell converter 50. Furthermore, control device 100 can also adjust the voltage of the power supplied to battery 10 by controlling the step-down operation of battery converter 40. Therefore, control device 100 can adjust the voltage of the power supplied to battery 10 to the charging voltage by appropriately controlling both the rectifying operation of fuel cell converter 50 and the step-down operation of battery converter 40. From the viewpoint of reducing the switching loss, control device 100 adjusts the voltage of the power supplied to battery 10 to the charging voltage only by controlling the rectification operation of fuel cell converter 50, and stops the switching operation of battery converter 40. You may

  When external connection unit 60 is connected to external AC power supply 201, power is received from external AC power supply 201 as shown by the double-dotted line arrow in FIG. 12 as in power supply system 1 described above. May be supplied to the inverter 31 and the drive motor 32.

(At the time of external power feeding)
Next, with reference to FIG. 13 and FIG. 14, the operation of the power supply system 2 at the time of external power feeding to the external AC load 202 will be described. In the application example, the external power feeding to the external AC load 202 includes power feeding to the external AC load 202 using the stored power of the battery 10 and power feeding to the external AC load 202 using the generated power of the fuel cell 20. . As will be described in detail below, in the application example, since both the stored power of the battery 10 and the generated power of the fuel cell 20 can be used to feed the external AC load 202, the external AC load 202 can be powered. Total power can be increased.

  First, with reference to FIG. 13, an operation of the power supply system 2 at the time of external power feeding to the external AC load 202 using the stored power of the battery 10 will be described. FIG. 13 is a schematic diagram showing the flow of power in the power supply system 2 at the time of external power feeding to the external AC load 202 using the stored power of the battery 10.

  When the electric powered vehicle is stopped, the external AC load 202 may be connected to the external connection unit 60. In such a case, control device 100 may control power supply system 2 such that the stored power of battery 10 is supplied to external AC load 202 via external connection unit 60, for example.

  When the external connection unit 60 is connected to the external AC load 202, the control device 100 controls the operation of the switching unit 59 to connect, for example, the fuel cell converter 50 to the external connection unit 60. Thereby, specifically, as shown in FIG. 13, chopper circuits 51 and 52 of fuel cell converter 50 are connected to external connection unit 60 by switches 591 and 592. Further, when the switching unit 59 is controlled as described above, the control device 100 controls the operation of the switching unit 49 to connect the battery converter 40 to the positive electrode side of the battery 10. Thus, specifically, as shown in FIG. 13, chopper circuits 41 and 42 of battery converter 40 are connected to the positive electrode side of battery 10 by switches 491 and 492.

  In control device 100, fuel cell converter 50 is connected to external connection unit 60 when external connection unit 60 is connected to external AC load 202, and switching unit 59 and switching unit 49 are controlled as described above. Thus, as shown in FIG. 13, the stored power of the battery 10 can be supplied to the external connection portion 60 side via the fuel cell converter 50. Thereby, it can be realized that the stored power of the battery 10 is supplied to the external AC load 202 via the external connection unit 60. At this time, the control device 100 converts the stored power of the battery 10 into an alternating current by the fuel cell converter 50 and supplies it to the external connection unit 60 side. The direct current to alternating current conversion operation by the fuel cell converter 50 is the same as the direct current to alternating current operation by the fuel cell converter 50 in the power supply system 1 described above, and thus the description thereof is omitted.

  Here, in the case where the storage power of the battery 10 is converted to an alternating current and supplied to the external connection unit 60 side, it is necessary to adjust the voltage at the output side (external connection unit 60 side) of the reactors 515 and 525 to a target value. .

  Control device 100 can adjust the voltage at the output side of reactors 515 and 525 by controlling the DC / AC conversion operation of fuel cell converter 50. Furthermore, control device 100 can also adjust the voltage at the output side of reactors 515 and 525 by controlling the step-up operation of battery converter 40. Therefore, control device 100 can adjust the voltage at the output side of reactors 515 and 525 to a target value by appropriately controlling both the DC / AC conversion operation of fuel cell converter 50 and the boost operation of battery converter 40. it can. From the viewpoint of reducing switching loss, control device 100 adjusts the voltage at the output side of reactors 515 and 525 to a target value only by controlling the DC / AC conversion operation of fuel cell converter 50, and performs switching operation of battery converter 40. May be stopped.

  When external connection unit 60 is connected to external AC load 202 and switching unit 59 and switching unit 49 are controlled as described above, arrows of dashed-two dotted lines in FIG. 13 as in power supply system 1 described above. The electric power regenerated by the load 30 may be converted into an alternating current by the fuel cell converter 50 and supplied to the external AC load 202, as shown by the equation (1).

  Next, with reference to FIG. 14, the operation of the power supply system 2 at the time of external power feeding to the external AC load 202 using the generated power of the fuel cell 20 will be described. FIG. 14 is a schematic view showing the flow of power in the power supply system 2 at the time of external power feeding to the external AC load 202 using the generated power of the fuel cell 20.

  When the external AC load 202 is connected to the external connection unit 60 when the electric vehicle stops, etc., in the control device 100, the generated power of the fuel cell 20 is supplied to the external AC load 202 via the external connection unit 60. To control the power supply system 2.

  When the external connection unit 60 is connected to the external AC load 202, the control device 100 controls the operation of the switching unit 59 to connect, for example, the fuel cell converter 50 to the positive electrode side of the fuel cell 20. Thus, specifically, chopper circuits 51 and 52 of fuel cell converter 50 are connected to the positive electrode side of fuel cell 20 by switches 591 and 592 as shown in FIG. When the switching unit 59 is controlled as described above, the control device 100 controls the operation of the switching unit 49 to connect the battery converter 40 to the external connection unit 60. Thereby, specifically, chopper circuits 41 and 42 of battery converter 40 are connected to external connection unit 60 by switches 491 and 492 as shown in FIG.

  In control device 100, battery converter 40 is connected to external connection unit 60 when external connection unit 60 is connected to external AC load 202 and switching unit 59 and switching unit 49 are controlled as described above. As shown in FIG. 14, the generated power of the fuel cell 20 can be supplied to the external connection unit 60 side via the battery converter 40. Thereby, it can be realized that the generated power of the fuel cell 20 is supplied to the external AC load 202 via the external connection portion 60.

  As described above, when the generated power of the fuel cell 20 is supplied to the external connection portion 60 side, the control device 100 converts the generated power of the fuel cell 20 into an alternating current by the battery converter 40 and the external connection portion 60 side. Supply to Specifically, control device 100 performs switching operation of upper switching elements 411 and 421 and lower switching elements 412 and 422 of chopper circuits 41 and 42 of battery converter 40 to convert generated power of fuel cell 20 into alternating current. To convert. Such operation of the battery converter 40 is also referred to as DC-AC conversion operation.

  When the battery converter 40 performs the DC / AC conversion operation, for example, the control device 100 causes the battery converter 40 to operate as a PWM inverter in the same manner as the DC / AC operation by the fuel cell converter 50 in the power supply system 1 described above.

  In this case, for example, the control device 100 generates triangular wave carrier waves and inverted carrier waves in the same manner as the direct current alternating current operation by the fuel cell converter 50 in the power supply system 1 described above. A sine wave signal wave having the same frequency as the target value of the voltage at the connection portion 60) is generated. Then, control device 100 generates a command signal for each switching element of battery converter 40 by comparing the carrier wave and the inverted carrier wave with the signal wave, and outputs the command signal to battery converter 40 to generate the command signal. Each switching element is caused to perform a corresponding switching operation.

  Thereby, the power generated by the fuel cell 20 is converted into an alternating current by the battery converter 40 and supplied to the external connection portion 60 side. Therefore, the power generated by the fuel cell 20 can be supplied to the external AC load 202 via the external connection portion 60. At this time, the voltage after direct current to alternating current conversion by the battery converter 40 substantially matches the target value.

  As described above, when external connection unit 60 is connected to external AC load 202, control device 100 connects battery converter 40 to external connection unit 60, and operates, for example, battery converter 40 as a PWM inverter. Thus, the generated power of the fuel cell 20 can be supplied to the external AC load 202 via the external connection portion 60.

  Here, in the case where the generated power of the fuel cell 20 is converted to an alternating current and supplied to the external connection unit 60 side, it is necessary to adjust the voltage on the output side (external connection unit 60 side) of the reactors 415 and 425 to a target value is there.

  Control device 100 can adjust the voltage at the output side of reactors 415 and 425 by controlling the DC / AC conversion operation of battery converter 40. Furthermore, control device 100 can also adjust the voltage at the output side of reactors 415 and 425 by controlling the boosting operation of fuel cell converter 50. Therefore, control device 100 adjusts the voltage at the output side of reactors 415 and 425 to a target value by appropriately controlling both the DC / AC conversion operation of battery converter 40 and the boost operation of fuel cell converter 50. it can. Control device 100 adjusts the voltage at the output side of reactors 415 and 425 to a target value only by controlling the DC / AC conversion operation of battery converter 40 from the viewpoint of reducing switching loss, and the switching operation of fuel cell converter 50 May be stopped.

  When external connection unit 60 is connected to external AC load 202 and switching unit 59 and switching unit 49 are controlled as described above, the arrow of the two-dot chain line in FIG. 14 as in power supply system 1 described above. The power regenerated by the load 30 may be converted into an alternating current by the battery converter 40 and supplied to the external AC load 202, as shown by

[effect]
Subsequently, the effects of the power supply system 2 according to the application example will be described.

  In the power supply system 2 according to the application example, the battery converter 40 includes a reactor whose one end is connected to the positive electrode side of the battery 10, an upper diode connected between the other end of the reactor and the positive electrode side of the load 30, A pair of parallel circuits including an upper switching element connected in parallel to the diode, a lower diode connected between the other end of the reactor and the negative electrode side of the battery 10, and a lower switching element connected in parallel to the lower diode The chopper circuit 41, 42 provided in A state in which the battery converter 40 is connected to the positive electrode side of the battery 10 on the battery 10 side from the connection points P41 and P42 of the upper diode, the lower diode and the reactor in the pair of chopper circuits 41 and 42 of the battery converter 40; A switching unit 49 is provided which can switch between the state where battery converter 40 is connected to external connection unit 60.

  Thereby, when external AC power supply 201 is connected to external connection portion 60, battery converter 40 is connected to external connection portion 60 to perform DC / AC conversion operation, whereby the generated power of fuel cell 20 is transmitted to external AC load 202. Can be fed via the external connection 60. Therefore, the battery converter 40 can be used for conversion of electric power in external power supply to the external AC load 202, for example, when the electric powered vehicle whose driving of the driving motor 32 is stopped is stopped. Therefore, it is possible to suppress the occurrence of a situation where the battery converter 40 is not used when the electrically powered vehicle is stopped or the like. Therefore, the utilization efficiency of the device in the power supply system 2 including the battery 10 and the fuel cell 20 can be further effectively improved.

  Furthermore, according to the application example, the use efficiency of the device in the power supply system 2 is further effectively improved, whereby the increase in the number of components in the power supply system 2 can be further effectively suppressed. For example, the power supply system 2 is prevented from additionally providing a device for performing conversion of power in external power supply to the external AC load 202 (specifically, conversion of DC power of the power source to AC current). be able to. Therefore, an increase in the size of the power supply system 2 can be suppressed more effectively.

  In the power supply system 2 according to the application example, when the external connection unit 60 is connected to the external AC load 202, the fuel cell 20 is connected by connecting the battery converter 40 to the external connection unit 60 and operating as a PWM inverter. The generated power can be supplied to the external AC load 202 via the external connection unit 60. Thus, the power generated by the fuel cell 20 can be supplied to the external AC load 202 while improving the power factor in the DC-AC conversion operation of the battery converter 40.

  Further, in the power supply system 2 according to the application example, when the battery converter 40 is subjected to a boost operation, the switching operations of the lower switching elements 412 and 422 of the pair of chopper circuits 41 and 42 of the battery converter 40 are mutually different. It can be done. Thereby, a phase difference can be generated between the current flowing through reactor 415 and the current flowing through reactor 425, so that the pulsating current ripple due to the switching operation of lower switching elements 412 and 422 can be reduced. it can.

  Further, in the power supply system 2 according to the application example, when the battery converter 40 performs the step-down operation, the switching operations of the upper switching elements 411 and 421 of the pair of chopper circuits 41 and 42 of the battery converter 40 are mutually generated. It can be done. Thereby, since a phase difference can be generated between the current flowing through reactor 415 and the current flowing through reactor 425, it is possible to reduce the pulsating current ripple due to the switching operation of upper switching elements 411 and 421. it can.

<6. End>
As described above, in the power supply system 1 according to the present embodiment, the fuel cell converter 50 is a reactor whose one end is connected to the positive electrode side of the fuel cell 20, between the other end of the reactor and the positive electrode side of the load 30. And a lower diode connected between the other end of the reactor and the negative electrode of the fuel cell 20, and a pair of lower switching elements connected in parallel to the lower diode. Chopper circuits 51 and 52 are provided. Further, the fuel cell converter 50 is connected to the positive electrode side of the fuel cell 20 on the fuel cell 20 side from the connection points P51 and P52 of the upper diode, the lower diode and the reactor in the pair of chopper circuits 51 and 52 of the fuel cell converter 50. A switching unit 59 is provided which can switch between the closed state and the state in which the fuel cell converter 50 is connected to the external connection unit 60.

  Thereby, since the fuel cell converter 50 can be used for conversion of the electric power in the external charging of the battery 10 when the electric vehicle stops, etc., the occurrence of a situation where the fuel cell converter 50 is not used is suppressed. can do. Therefore, the utilization efficiency of the device in the power supply system 1 including the battery 10 and the fuel cell 20 can be improved. Furthermore, according to the present embodiment, the use efficiency of the devices in the power supply system 1 is improved, so that the increase in the number of parts in the power supply system 1 can be suppressed, so the enlargement of the power supply system 1 is suppressed. can do.

  Although the preferred embodiments of the present invention have been described in detail with reference to the accompanying drawings, the present invention is not limited to such examples. It is obvious that those skilled in the art to which the present invention belongs can conceive of various modifications or applications within the scope of the technical idea described in the claims. Of course, it is understood that these also fall within the technical scope of the present invention.

1, 1a, 1b, 2 power supply system 10 battery 11 battery management unit 20 fuel cell 30 load 31 inverter 32 driving motor 40 battery converter 41, 42 chopper circuit 49 switching unit 50, 50a, 50b fuel cell converter 51, 52, 53 , 54 chopper circuit 59, 59b switching unit 60, 60b external connection unit 100 control device 201 external AC power supply 202 external AC load

Claims (9)

A battery connected to a load and storing power supplied to the load;
A fuel cell connected to the load in parallel with the battery via a fuel cell converter capable of converting voltage;
An external connection portion capable of receiving power supplied from the external AC power supply in a state of being connected to the external AC power supply;
In a power supply system comprising
The fuel cell converter includes a reactor whose one end is connected to the positive electrode side of the fuel cell, an upper diode connected between the other end of the reactor and the positive electrode side of the load, the other end of the reactor and the fuel cell A pair of chopper circuits provided in parallel with each other, including a lower diode connected between the negative electrode side and the lower diode and a lower switching element connected in parallel to the lower diode;
A switching unit for connecting and disconnecting the fuel cell converter and the positive electrode side of the fuel cell is provided on the fuel cell side from the connection point of the upper diode, the lower diode and the reactor in the pair of chopper circuits of the fuel cell converter
The switching unit of the fuel cell converter is capable of switching between a state in which the fuel cell converter is connected to the positive electrode side of the fuel cell and a state in which the fuel cell converter is connected to the external connection portion.
A controller for controlling the operation of the fuel cell converter;
Power system. In each of the pair of chopper circuits of the fuel cell converter, the upper switching element is connected in parallel to the upper diode.
The power supply system according to claim 1. The control device connects the fuel cell converter to the external connection portion to operate as a PWM rectifier when the external connection portion is connected to the external AC power supply, whereby the external connection from the external AC power supply is performed. Charging the battery using power received via the
The power supply system according to claim 2. When the external connection unit is connected to an external alternating current load, the control device causes the fuel cell converter to be connected to the external connection unit to operate as a PWM inverter, whereby the storage power of the battery is converted to the external alternating current Feed the load via the external connection,
The power supply system according to claim 2 or 3. The control device causes the lower switching elements of the pair of chopper circuits of the fuel cell converter to perform switching operations so as to cause a phase difference when the fuel cell converter is subjected to a boost operation.
The power supply system according to any one of claims 1 to 4. The battery is connected to the load in parallel with the fuel cell and the fuel cell converter through a battery converter capable of converting a voltage,
In the battery converter, a reactor whose one end is connected to the positive electrode side of the battery, an upper diode connected between the other end of the reactor and the positive electrode side of the load, and an upper switching connected in parallel to the upper diode A pair of chopper circuits provided in parallel with each other, including a device, a lower diode connected between the other end of the reactor and the negative electrode side of the battery, and a lower switching device connected in parallel with the lower diode;
A switching unit for connecting and disconnecting the battery converter and the positive electrode side of the battery is provided on the battery side from the connection point of the upper diode, the lower diode and the reactor in the pair of chopper circuits of the battery converter;
The switching unit of the battery converter is capable of switching between the state in which the battery converter is connected to the positive electrode side of the battery and the state in which the battery converter is connected to the external connection portion.
The control device controls the operation of the battery converter,
The power supply system according to any one of claims 1 to 5. When the external connection portion is connected to an external AC load, the control device causes the battery converter to be connected to the external connection portion to operate as a PWM inverter, whereby the power generated by the fuel cell is converted to the external AC. Feed the load via the external connection,
The power supply system according to claim 6. The control device causes the lower switching elements of the pair of chopper circuits of the battery converter to perform a switching operation so as to cause a phase difference when the battery converter is subjected to a boost operation.
The power supply system according to claim 6 or 7. The control device switches the upper switching elements of the pair of chopper circuits of the battery converter so as to cause a phase difference when the battery converter is operated to step down the battery converter.
The power supply system according to any one of claims 6 to 8.

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