JP6630588B2 - Power supply device, device and control method - Google Patents

Description

  The present invention relates to a power supply, a device, and a control method.

  A polyphase converter in which a plurality of voltage conversion capable converters are connected in parallel has a current sensor, and a detection value of the current sensor is used for controlling the polyphase converter. In the current sense component failure detection in a multi-phase power system described in Patent Literature 1, a detected value of a current detector (sensor device) exceeds an upper threshold or When the period below the lower threshold exceeds the switching cycle, a failure of the current detection unit is determined based on an abnormality of a component included in the current detection unit. A similar technique is also described in Patent Document 2.

US Patent Application Publication No. 2004/0189315 JP-A-10-253682

  In the technique described in Patent Literature 1, control of the polyphase power system after the failure of the current detection unit is detected is not considered. However, if the multi-phase power system is mounted on transportation equipment or electric equipment and used to supply power to the main parts of the equipment, power supply to the main parts will be maintained even if the current detection unit fails. It is desirable to be able to continue. In addition, in the multi-phase power system, high-efficiency power supply can be realized by appropriately changing the number of power supply phases according to the load condition. Therefore, even if the current detection unit fails, it is more desirable that the number of phases to be supplied with power can be changed.

  An object of the present invention is to provide a power supply device, a device, and a control method that have high control continuity even when a sensor that detects a current fails.

In order to achieve the above object, the invention described in claim 1 is
A power source (for example, a fuel cell 101 in an embodiment described later);
A conversion module (e.g., FC-VCU 103, 203 in an embodiment described later) having a plurality of conversion units capable of converting the voltage of the power supplied by the power supply, and the plurality of conversion units being electrically connected in parallel. When,
A first current sensor (for example, a current sensor 105 in an embodiment described later) that detects a current flowing between the power supply and the conversion module,
A second current sensor (for example, a phase current sensor 1051 to 1054 in an embodiment described later) that detects a current flowing through each of the plurality of conversion units,
A first control unit (for example, a first control unit that performs a first control that changes the number of operations that is the number of the conversion units that perform the voltage conversion using a detection value of the first current sensor or a detection value of the second current sensor) ECU 113 in an embodiment described later),
In the case where the number of operations is plural, a second control unit (for example, in an embodiment to be described later) that performs a second control for equalizing the current flowing through the conversion unit of the number of operations using the detection value of the second current sensor. ECU 113),
Depending on whether the first current sensor and the second current sensor are normal or abnormal, a detection value used in performing the first control is a detection value of the first current sensor and the second current sensor. A determination unit (for example, the ECU 113 in an embodiment to be described later) that determines one of the detected values of the above and determines whether to perform the second control.
A power supply device comprising:
Note that the first control unit, the second control unit, and the determination unit may be shared by the same ECU 113 having a plurality of functions described in embodiments described later.

The invention according to claim 2 is the invention according to claim 1,
If the first current sensor and the second current sensor are normal, the determination unit determines a detection value used when performing the first control as a detection value of the first current sensor, and Decide to do.

According to the invention described in claim 3, in the invention described in claim 1 or 2,
The determining unit determines that the second control is to be performed using a detection value of the second current sensor when at least the second current sensor is normal.

The invention according to claim 4 is the invention according to any one of claims 1 to 3,
If the first current sensor is normal and the second current sensor is abnormal, the determination unit determines a detection value used when performing the first control as a detection value of the first current sensor, It is determined that the second control is not performed.

The invention according to claim 5 is the invention according to any one of claims 1 to 4,
If the first current sensor is abnormal and the second current sensor is normal, the determination unit determines a detection value used when performing the first control as a detection value of the second current sensor, Determining to perform the second control,
The first control unit performs the first control using a total value of the detection values of the second current sensor.

The invention according to claim 6 is the invention according to any one of claims 1 to 5,
A control unit that drives the conversion unit that performs the voltage conversion and controls the conversion module,
If the first current sensor or the second current sensor is abnormal, the control unit performs control to reduce an input current from the power supply to the conversion module.

The invention according to claim 7 is the invention according to any one of claims 1 to 6,
A control cycle of the first control using a detection value of the first current sensor is different from a control cycle of the second control.

The invention according to claim 8 is the invention according to claim 7,
A control cycle of the first control using the detection value of the first current sensor is earlier than a control cycle of the second control.

  According to a ninth aspect of the present invention, there is provided an apparatus having the power supply device according to any one of the first to eighth aspects.

The invention according to claim 10 is
A power source (for example, a fuel cell 101 in an embodiment described later);
A conversion module (e.g., FC-VCU 103, 203 in an embodiment described later) having a plurality of conversion units capable of converting the voltage of the power supplied by the power supply, and the plurality of conversion units being electrically connected in parallel. When,
A first current sensor (for example, a current sensor 105 in an embodiment described later) that detects a current flowing between the power supply and the conversion module,
A second current sensor (for example, a phase current sensor 1051 to 1054 in an embodiment described later) that detects a current flowing through each of the plurality of conversion units,
A first control unit (for example, a first control unit that performs a first control that changes the number of operations that is the number of the conversion units that perform the voltage conversion using a detection value of the first current sensor or a detection value of the second current sensor) ECU 113 in an embodiment described later),
In the case where the number of operations is plural, a second control unit (for example, in an embodiment to be described later) that performs a second control for equalizing the current flowing through the conversion unit of the number of operations using the detection value of the second current sensor. ECU 113), the control method performed by the power supply device comprising:
Depending on whether the first current sensor and the second current sensor are normal or abnormal, a detection value used in performing the first control is a detection value of the first current sensor and the second current sensor. And a control method for determining whether or not to perform the second control.
Note that the first control unit and the second control unit may be shared by the same ECU 113 having a plurality of functions described in embodiments described later.

  According to the first, ninth, and tenth aspects of the present invention, even if one of the first current sensor and the second current sensor fails, control relating to a change in the number of operations based on at least the input current to the conversion module. Can be continued, and control can be continued so that the load is not concentrated on a part of the plurality of conversion units.

  The current value flowing into the conversion module from the power supply flows through at least one conversion part. Therefore, the total value of the detection value of the first current sensor provided in the preceding stage of the plurality of conversion units and the detection value of the second current sensor provided in each of the plurality of conversion units is theoretically equal. However, in practice, each current sensor has an unavoidable product error. Therefore, the sum of the detection values of the first current sensor and the detection values of the second current sensor is not always equal. In particular, when detecting the current flowing into the conversion module by using the second current sensor, it is necessary to use a plurality of current sensors, and therefore, there is a high possibility that the error from the actual current value will increase. According to the invention of claim 2, from the viewpoint of detecting the current value flowing into the conversion module, the detection value of the first current sensor, which is more accurate than the second current sensor, is used for the first control. By performing the second control with high accuracy, the load on the conversion unit can be equalized.

  If the converters have the same structure, the current flowing through each converter is theoretically equal. However, in practice, the current flowing through each converter is not always equal due to various parameters such as the deterioration state of each converter and product errors of components of the converter. According to the third aspect of the present invention, the load on the converters can be equalized by performing the second control using the detection value of the second current sensor provided in each converter.

  According to the invention of claim 4, since the second control is not performed, a slight deviation occurs in the current flowing through each converter, but the current flowing into the conversion module by continuing the first control. Since the number of converters that perform voltage conversion is appropriately changed according to the value, the plurality of converters share the current flowing into the conversion module, and the concentration of load on some converters can be suppressed.

  According to the fifth aspect of the present invention, by continuing the first control using the total value of the currents of the respective converters detected by the second current sensor, the accuracy is higher than when the detection value of the first current sensor is used. Although low, the number of operations can be changed even if the first current sensor fails. In this case, although the efficiency of voltage conversion is slightly impaired, the current value flowing through each conversion unit is equalized by the second control using the detection value of the second current sensor. The concentration of the load on the conversion unit does not occur, and the high durability and long life of the conversion module are not impaired.

  If one of the first current sensor and the second current sensor fails, as described above, one of the first control and the second control cannot be executed, or the control accuracy and control stability are reduced. According to the invention of claim 6, by performing control to reduce the input current from the power supply to the conversion module, the control accuracy and control stability when the first current sensor or the second current sensor is abnormal are reduced. Can be complemented.

  According to the invention of claim 7, the control cycle is mainly determined based on the difference between the role of the first control using the detection value of the first current sensor and the role of the second control using the detection value of the second current sensor. Therefore, the first control and the second control can be stably performed while suppressing competition (hunting) between the first control and the second control and an increase in the calculation load of the control device.

  According to the invention of claim 8, since the second control is an auxiliary role of the first control, the control cycle is set based on the difference between the role of the first control and the role of the second control. The first control and the second control can be stably performed while suppressing competition (hunting) between the first control and the second control and an increase in the calculation load of the control device.

1 is a block diagram illustrating a schematic configuration of an electric vehicle equipped with a power supply device according to an embodiment of the present invention. FIG. 2 is an electric circuit diagram illustrating a relationship among a power supply device, a battery, a VCU, a PDU, and a motor generator according to the embodiment. FIG. 7 is a diagram illustrating a change over time of a switching signal and an input / output current of the FC-VCU when only one of four conversion units (phases) of the FC-VCU is driven. FIG. 7 is a diagram illustrating a change over time of a switching signal and input / output current of the FC-VCU when driving all four conversion units (phases) of the FC-VCU. It is a graph which shows the energy efficiency of FC-VCU which considered the loss with respect to the input current for every several N of the converter (phase) to drive. FIG. 3 is a diagram illustrating a positional relationship between components of a four conversion unit (phase) and a smoothing capacitor of the FC-VCU illustrated in FIG. 2 when viewed from a Z-axis direction. FIG. 9 is an electric circuit diagram illustrating a relationship among a power supply device, a battery, a VCU, a PDU, and a motor generator according to another embodiment. FIG. 8 is a diagram illustrating a positional relationship between components and smoothing capacitors of four conversion units (phases) included in the FC-VCU illustrated in FIG. 7 when viewed from a Z-axis direction. FIG. 4 is a diagram of a first control example showing phases to be driven for each drive pattern in the FC-VCU, for each number of operating phases. 5 is a flowchart illustrating a procedure for selecting a drive pattern of an FC-VCU by an ECU according to a first control example . FIG. 11 is a diagram of a second control example showing phases to be driven for each drive pattern in the FC-VCU, for each number of operating phases. 9 is a flowchart illustrating a procedure of selecting an FC-VCU drive pattern by an ECU according to a second control example . 9 is a graph showing a loss ηtotal_N in the FC-VCU with respect to the input current IFC for each number N of operating phases when the input power of the FC-VCU is constant. 5 is a graph showing a loss in the FC-VCU with respect to a boosting rate when the FC-VCU is driven with a predetermined number of phases while the input power is constant. It is a figure which shows each loss map in FC-VCU of the number of operation phases of one phase, two phases, and four phases. 5 is a graph showing an IV characteristic of a fuel cell in which a closed circuit voltage changes according to an output current . FIG. 16 is a diagram illustrating a combined loss map in which minimum loss values hatched by the three loss maps illustrated in FIG. 15 are extracted. FIG. 13 is a diagram of a fourth control example showing the phases to be driven for each drive pattern in the FC-VCU for each number of operating phases. It is a figure which shows the time-dependent change of phase current IL1-IL4 which flows through each phase when FC-VCU is driven by four phases. It is a figure which shows the time-dependent change of the phase current IL1-IL4 which flows through each phase when FC-VCU is driven by three phases. When switching the number of operating phases of the FC-VCU from one phase to two phases, duty ratios D1 and D2 of the on / off switching control for the switching elements of the driving phase 1 and the driving phase 2 and the phase currents IL1 and IL2 FIG. 13 is a diagram of a fifth control example showing an example of a change with time of the input current IFC. When the number of operating phases of the FC-VCU is switched from two to one, the duty ratios D3 and D4 of the on / off switching control for the switching elements of phase 1 that continues driving and phase 2 that stops driving, and each phase current IL1 FIG. 13 is a diagram of a fifth control example illustrating an example of a change with time of the IL2 and the input current IFC. FIG. 14 is a diagram of a fifth control example illustrating an example of a relationship between a threshold value of an input current IFC for switching the number of operating phases and a change amount of a phase current flowing in a driving phase accompanying the switching of the number of operating phases. 13 is a flowchart illustrating an operation performed by an ECU of a fifth control example when switching the number of operating phases of the FC-VCU. FIG. 18 is a diagram of a fifth control example showing another example of the relationship between the threshold value of the input current IFC for switching the number of operating phases and the amount of change in the phase current flowing through the driving phase accompanying the switching of the number of operating phases. When the number of operating phases of the FC-VCU controlled at the switching frequency f is one, when the number of operating phases of the FC-VCU controlled at the switching frequency f / 2 is one, and the control is performed at the switching frequency f / 2 FIG. 13 is a diagram of a sixth control example showing an example of a change with time of the output current and the input current IFC of the FC-VCU when the number of operating phases of the FC-VCU is two-phase and interleaved. FIG. 13 is a diagram illustrating an example of a relationship between an input current IFC and a switching frequency, the number of operating phases, and a frequency of an input / output current when the ECU of the sixth control example controls the FC-VCU. The figure which shows an example of the relationship between the input current IFC and the switching frequency, the number of operating phases, and the frequency of input / output current when the ECU which does not perform control of the 6th control example determines the number of operating phases based on the loss of FC-VCU. It is. FIG. 16 is a diagram illustrating another example of the relationship between the input current IFC and the switching frequency, the number of operating phases, and the frequency of the input / output current when the ECU of the sixth control example controls the FC-VCU. It is a graph which shows the loss (eta) total_N in FC-VCU with respect to the input current IFC for every number N of operation phases. FIG. 9 is a diagram illustrating a case where a phase current flowing through a driving phase increases when an input current IFC decreases and the number of operating phases decreases by performing power save control. FIG. 17 is a diagram of a seventh control example showing a case where the number of operating phases of the FC-VCU is increased from the number of phases before the power save control without depending on the input current IFC during the power save control. 13 is a flowchart illustrating an operation performed by an ECU of a seventh control example when the temperature of the FC-VCU exceeds a threshold value. It is a figure of the 8th example of control which shows the electric current value for the number of operation phases, the electric current value for phase current balance control, and the presence or absence of execution of power save control for every different state of a current sensor and a phase current sensor. It is a flowchart which shows the operation | movement which ECU of 8th control example performs according to the state of a current sensor and a phase current sensor. It is a block diagram showing a schematic structure of an electric vehicle in which a power supply device having an ECU of a ninth control example is mounted. FIG. 21 is a diagram of a tenth control example illustrating a basic amplitude of an AC signal according to the number of operation phases of the FC-VCU and a temporal change of the basic amplitude total value. FIG. 4 is an enlarged view illustrating an input current value near 0 (A) for explaining a difference in waveform of an input current IFC due to a magnitude of an AC signal superimposed when driving an FC-VCU in one phase. It is a figure which shows the relationship between the boost rate of FC-VCU, and the coefficient which multiplies a basic superposition amount. FIG. 21 is a diagram of an eleventh control example showing a basic amplitude of an AC signal according to the number of operation phases of the FC-VCU and a temporal change of the basic amplitude total value. FIG. 4 is an enlarged view illustrating an input current value near 0 (A) for explaining a difference in waveform of an input current IFC due to a magnitude of an AC signal superimposed when driving an FC-VCU in one phase. It is a figure which shows the relationship between the boost rate of FC-VCU, and the coefficient which multiplies a basic superposition amount. It is a flowchart which shows the operation | movement which ECU of 11th control example performs when superimposing an alternating current signal on the control signal of a drive phase. FIG. 7 is a block diagram illustrating a schematic configuration of an electric vehicle equipped with a power supply device according to another embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a block diagram showing a schematic configuration of an electric vehicle equipped with a power supply device according to an embodiment of the present invention. In FIG. 1, a thick solid line indicates a mechanical connection, a double dotted line indicates a power wiring, and a thin solid arrow indicates a control signal. The 1MOT type electric vehicle shown in FIG. 1 includes a motor generator (MG) 11, a PDU (Power Drive Unit) 13, a VCU (Voltage Control Unit) 15, a battery 17, and a power supply device 100 of one embodiment. Prepare. Hereinafter, each component included in the electric vehicle will be described.

  Motor generator 11 is driven by electric power supplied from at least one of battery 17 and power supply device 100, and generates motive power for the electric vehicle to travel. The torque generated by motor generator 11 is transmitted to drive wheels W via gear box GB including a shift speed or a fixed speed and differential gear D. The motor generator 11 operates as a generator when the electric vehicle decelerates, and outputs a braking force of the electric vehicle. Note that regenerative electric power generated by operating motor generator 11 as a generator is stored in battery 17.

  The PDU 13 converts a DC voltage into a three-phase AC voltage and applies the same to the motor generator 11. Further, PDU 13 converts an AC voltage input during a regenerative operation of motor generator 11 into a DC voltage.

  The VCU 15 boosts the output voltage of the battery 17 while maintaining the direct current. In addition, VCU 15 reduces the voltage of electric power generated by motor generator 11 and converted into direct current when the electric vehicle decelerates. Further, the VCU 15 drops the output voltage of the power supply device 100 while keeping the DC voltage. The power stepped down by the VCU 15 is charged in the battery 17.

  Battery 17 has a plurality of storage cells such as a lithium ion battery and a nickel hydride battery, and supplies high-voltage power to motor generator 11 via VCU 15. Note that the battery 17 is not limited to a secondary battery such as a lithium ion battery or a nickel hydride battery. For example, a capacitor or a capacitor which has a small storable capacity but can charge and discharge a large amount of power in a short time may be used as the battery 17.

  As shown in FIG. 1, the power supply device 100 includes a fuel cell (FC) 101, an FC-VCU (Fuel Cell Voltage Control Unit) 103, a current sensor 105, and phase current sensors 1051 to 1054 (see FIG. 2). , Voltage sensors 1071 and 1072, temperature sensors 1091 to 1094 (see FIG. 2), a power switch 111, and an ECU (Electronic Control Unit) 113.

  The fuel cell 101 has a hydrogen tank, a hydrogen pump, and an FC stack. The hydrogen tank stores hydrogen, which is a fuel for the electric vehicle to run. The hydrogen pump regulates the amount of hydrogen sent from the hydrogen tank to the FC stack. In addition, the hydrogen pump can also adjust the humidification amount of hydrogen by supplying dry hydrogen stored in the hydrogen tank to the FC stack after passing through a water storage tank in the hydrogen pump. The FC stack takes in hydrogen supplied from a hydrogen pump and oxygen in the air, and generates electric energy by a chemical reaction. The electric energy generated by the FC stack is supplied to the motor generator 11 or the battery 17.

  The fuel cell 101 includes, in addition to a polymer electrolyte fuel cell (PEFC), a phosphoric acid fuel cell (PAFC) and a molten carbonate fuel cell (MCFC = Molten Carbonate). Various types of fuel cells, such as a fuel cell and a solid oxide fuel cell (SOFC), can be applied.

Note that the closed circuit voltage of the fuel cell 101 fluctuates according to the output current . Further, the characteristics of the fuel cell 101 and the characteristics of the battery 17 described above are different from each other. The fuel cell 101 can continuously discharge a large current as long as hydrogen and oxygen as fuels are supplied. However, it is difficult to fluctuate the output of the fuel cell 101 discontinuously in a short time due to the principle of generating electricity by an electrochemical reaction of the supplied fuel gas. Considering these characteristics, it can be said that the fuel cell 101 has characteristics as a high-capacity power supply. On the other hand, it is difficult for the battery 17 to continuously discharge a large current due to the principle of generating electricity by an electrochemical reaction of an internal active material, but it is never possible to fluctuate its output discontinuously in a short time. Not difficult. Considering these characteristics, it can be said that the battery 17 has characteristics as a high-output type power supply.

  The FC-VCU 103 has four conversion units capable of converting the voltage of the electric power (electric energy) output from the fuel cell 101, connects them in parallel with each other, and shares an output node and an input node with each other. It is a polyphase converter. FIG. 2 is an electric circuit diagram showing a relationship among the power supply device 100, the battery 17, the VCU 15, the PDU 13, and the motor generator 11. As shown in FIG. 2, each converter included in the FC-VCU 103 has a circuit configuration of a boost chopper circuit including a reactor, a diode connected in series to the reactor, and a switching element connected between the reactor and the diode. Have. A smoothing capacitor C1 is provided on the input side of the FC-VCU 103 in parallel with the four converters, and a smoothing capacitor C2 is provided on the output side of the FC-VCU 103 in parallel with the VCU 15.

  The four conversion units of the FC-VCU 103 are electrically connected in parallel, and the switching elements of at least one of the conversion units are turned on / off at a desired timing, thereby boosting the voltage of the fuel cell 101 while maintaining the DC voltage. And output. The on / off switching operation of the switching element of the conversion unit is controlled by a pulse-like switching signal having a predetermined duty ratio from the ECU 113 to the FC-VCU 103.

  The number of converters driven by the control of the ECU 113 affects the ripple of the output current of the FC-VCU 103. When on / off switching control of the switching element of the conversion unit is performed, the input current to the FC-VCU 103 flows to the switching element side during the ON operation, and the reactor stores energy. During the OFF operation, the input current to the FC-VCU 103 is a diode. Flowing to the side, the reactor releases the stored energy. For this reason, when only one of the four converters of the FC-VCU 103 is driven, as shown in FIG. 3, the FC-VCU 103 outputs a current flowing through the converter in the OFF operation. When all four conversion units of the FC-VCU 103 are driven, interleave control is performed to shift the on / off switching phase of each conversion unit by 90 degrees as shown in FIG. In this case, the ripple of the output current of the FC-VCU 103 is smaller than the case where only one converter shown in FIG. 3 is driven by combining the output current of each converter at the output node of the FC-VCU 103. When two of the four converters included in the FC-VCU 103 are driven, interleave control is performed to shift the on / off switching phase of each converter to be driven by 180 degrees. At this time, the ripple of the output current of the FC-VCU 103 is larger than the case where the four converters shown in FIG. 4 are driven, but smaller than the case where only one converter shown in FIG. 3 is driven. As described above, the ripple of the output current changes depending on the number of converters to be driven. Ripple in the output current can be minimized if the phase difference between the driving converters is equal to the value divided by the number of converters driving 360 degrees.

  The number of converters to be driven also affects the loss generated in the FC-VCU 103. The loss generated in the FC-VCU 103 includes a transition loss ηtrans generated when the switching element transitions between the on and off states, a conduction loss ηconduct generated from a resistance component of the switching element and the like, and a switching loss ηswitch generated by switching. (Fsw).

When only one of the four conversion units is driven, the loss ηtotal_1 generated in the FC-VCU 103 is represented by the following equation (1). Here, “IFC” is an input current to the FC-VCU 103, “V1” is an input voltage of the FC-VCU 103, and “V2” is an output voltage of the FC-VCU 103. “Ttrans _” is a transition time from on to off or from off to on in the switching element, “Fsw _” is a switching frequency, and “RDSon” is an on-resistance of the switching element constituting the converter. “A” is a constant.

Based on the loss ηtotal_1 shown in the equation (1), the conduction loss particularly increases as the input current IFC to the FC-VCU 103 increases, and the calorific value of the FC-VCU 103 increases. Therefore, when increasing the number of converters to be driven and driving N converters (N is an integer of 2 or more), the loss ηtotal_N generated in the FC-VCU 103 is represented by the following equation (2). .

  Based on the loss ηtotal_N shown in equation (2), the switching loss increases as the number of converters to be driven increases, but the conduction loss decreases. For this reason, the ECU 113 selects the number of converters to be driven using a map or the like showing the energy efficiency of the FC-VCU 103 in consideration of the loss for each number N of converters to be driven. FIG. 5 is a graph showing the energy efficiency of the FC-VCU 103 in consideration of the loss with respect to the input current IFC for each number N of converters to be driven. The ECU 113 selects an appropriate number N according to the input current IFC to the FC-VCU 103 from the map based on the graph of FIG.

  FIG. 6 is a diagram illustrating a positional relationship of each component of the four conversion units and the smoothing capacitors C1 and C2 of the FC-VCU 103 illustrated in FIG. 2 when viewed from the Z-axis direction. In the following description, each of the four conversion units of the FC-VCU 103 is expressed as a “phase”. Therefore, in the present embodiment, as shown in FIG. 6, the converter including the reactor L1 is “phase 1”, the converter including the reactor L2 is “phase 2”, the converter including the reactor L3 is “phase 3”, The converter including the reactor L4 is referred to as “phase 4”. If the number of driving converters (phases) to be driven (hereinafter, also referred to as “the number of operating phases”) is one, “one phase”, and the number of converters (phases) to be driven is two In this case, the number of operating phases is represented as “N-phase” by the number N of converters (phases) to be driven, such as “two-phase”.

  As shown in FIG. 6, in the present embodiment, phases 1 to 4 are arranged in a line on the XY plane, and phases 1 and 4 are arranged on the outermost sides on the XY plane. Phase 2 is arranged inside, and phase 3 is arranged inside phase 4. Further, the iron core of reactor L1 forming phase 1 and the iron core of reactor L2 forming phase 2 are shared, and the winding directions of the coils of each reactor with respect to the iron core are opposite to each other. Similarly, the iron core of reactor L3 and the iron core of reactor L4 are shared, and the winding directions of the coils of each reactor with respect to the iron core are opposite to each other. Therefore, reactor L1 and reactor L2 are magnetically coupled to each other, and reactor L3 and reactor L4 are magnetically coupled to each other.

  Further, FIG. 6 shows that when the same current is applied to the reactors magnetically coupled to each other, the magnetic fluxes generated in the respective phases are canceled. Current IL3 flowing through reactor L3 generates magnetic flux 3 and current IL4 flowing through reactor L4 generates magnetic flux 4 by electromagnetic induction. As described above, since the iron core of the reactor L3 and the iron core of the reactor L4 are shared, the magnetic fluxes 3 and 4 are opposite to each other and cancel each other. Therefore, magnetic saturation in reactor L3 and reactor L4 can be suppressed. The same applies to reactor L1 and reactor L2.

  Further, iron core Coa shared by reactor L1 and reactor L2 is disposed on the XY plane over phase 1 and phase 2, and iron core Cob shared by reactor L3 and reactor L4 is phase 3 and phase L2. The phase 4 is arranged on the XY plane. The XY plane may be a horizontal plane or a vertical plane. The number of reactors to be magnetically coupled is not limited to two. By sharing the iron core as described above, three, four or more reactors can be magnetically coupled.

  The induced currents IL1 to IL4 of the reactors L1 to L4 in each phase are input to a node Node2 connected to a node connecting one end of the switching element and one end of the diode. A node Node1 at the other end of the switching element is connected to a ground line. The output current of each phase is output from a node Node3 at the other end of the diode.

  In addition, as shown in FIG. 7, the iron core of each reactor constituting phase 1 to phase 4 may be independent. However, even in this case, as shown in FIG. 8, phases 1 to 4 are arranged in a line on the XY plane, and phases 1 and 4 are arranged on the outermost sides on the XY plane. , Phase 1 is arranged inside phase 1 and phase 3 is arranged inside phase 4.

  The current sensor 105 and the phase current sensors 1051 to 1054 included in the power supply device 100 are so-called Hall-type current sensors that do not have an electrical contact (node) with a circuit whose current is to be detected. Each current sensor has a core and a Hall element, and a Hall element, which is a magnetoelectric conversion element, converts a magnetic field proportional to an input current generated in a gap between the cores into a voltage. The current sensor 105 detects an input current IFC to the FC-VCU 103, which is also an output current of the fuel cell 101. A signal indicating a voltage corresponding to the input current IFC detected by the current sensor 105 is sent to the ECU 113. The phase current sensors 1051 to 1054 shown in FIG. 2 detect phase currents IL1 to IL4 flowing through each phase (each conversion unit) of the FC-VCU 103. A signal indicating a voltage corresponding to the phase currents IL1 to IL4 detected by the phase current sensors 1051 to 1054 is sent to the ECU 113. Note that the control cycle of the current sensor 105 and the control cycle of the phase current sensors 1051 to 1054 are different from each other in order to prevent control interference in the ECU 113. In the present embodiment, the control cycle of the current sensor 105 is earlier than the control cycle of the phase current sensors 1051 to 1054. This balances the current sensor 105, which greatly affects the efficiency of the FC-VCU 103, that is, the change in the number of operating phases using the detected value, and the current value of each phase driven using the detected value. This is due to the difference in the role of the auxiliary phase current sensors 1051 to 1054.

  The voltage sensor 1071 detects an input voltage V1 of the FC-VCU 103, which is also an output voltage of the fuel cell 101. A signal indicating voltage V1 detected by voltage sensor 1071 is sent to ECU 113. Voltage sensor 1072 detects output voltage V2 of FC-VCU 103. A signal indicating voltage V2 detected by voltage sensor 1072 is sent to ECU 113.

  The temperature sensors 1091 to 1094 detect the temperature of the FC-VCU 103, in particular, the temperature near the switching element of each phase (each conversion unit). Signals indicating the temperatures T1 to T4 detected by the temperature sensors 1091 to 1094 are sent to the ECU 113.

  The power switch 111 is a switch operated by a driver when starting or stopping the electric vehicle on which the power supply device 100 is mounted. When the power switch 111 is operated (turned on) when the electric vehicle is stopped, a power switch signal indicating activation is input to the ECU 113. On the other hand, when the power switch 111 is operated (turned off) while the electric vehicle is operating, a power switch signal indicating a stop is input to the ECU 113.

  The ECU 113 controls the fuel cell 101, selects a phase to be driven among the four phases constituting the FC-VCU 103, and controls on / off switching by a switching signal supplied to a switching element of the selected phase, and controls the PDU 13 and the VCU 15. I do. Further, the ECU 113 performs power distribution control using the VCU 15 so as to utilize the characteristics of the fuel cell 101 and the battery 17 having different characteristics. By performing this power distribution control, the fuel cell 101 is used to supply a constant amount of power to the motor generator 11 during acceleration running of the electric vehicle, and the battery 17 has a large driving force for running the electric vehicle. It is used to supply power to motor generator 11 when needed. When the electric vehicle is running at a reduced speed, the ECU 113 charges the battery 17 with regenerative power generated by the motor generator 11.

Further, the ECU 113 controls the FC-VCU 103 according to first to eleventh control examples described below. Hereinafter, the control of each control example will be described in detail with reference to the drawings.

(First control example )
The ECU 113 of the first control example switches the driving pattern of the phase in the FC-VCU 103 based on the on / off operation of the power switch 111.

FIG. 9 is a diagram of a first control example showing phases to be driven for each driving pattern in the FC-VCU 103 for each number of operating phases. The ECU 113 of the first control example controls the FC-VCU 103 based on one of the four drive patterns shown in FIG. For example, when the FC-VCU 103 is driven in one phase in the driving pattern 1, the ECU 113 controls the on / off switching of the switching element of the phase 1, and when driven in two phases, the switching element of the phase 1 and the phase 2 is 180. On / off switching control is performed with a phase difference of degrees, and when driving in four phases, on / off switching control of each of the switching elements of phase 1 to phase 4 is performed with a phase difference of 90 degrees. In the case of two phases, the phase to be driven in the case of one phase and the phase in which the iron core of the reactor and the phase are shared, such as “phase 1 and phase 2” or “phase 3 and phase 4” In other words, two phases of the phase and the magnetically coupled phase are driven. However, when the iron core of each phase reactor shown in FIGS. 7 and 8 drives the independent FC-VCU 203 in two phases, one of the phase driven in the case of one phase and the other three phases One is driven. In the driving pattern of the FC-VCU 103 shown in FIG. 9, three-phase operation is excluded for the reason described later. However, when the FC-VCU 203 shown in FIGS. May be. The number of operating phases of the FC-VCUs 103 and 203 is determined by the ECU 113 based on the input current IFC to the FC-VCU 103.

FIG. 10 is a flowchart illustrating a procedure for selecting a drive pattern of the FC-VCU 103 by the ECU 113 in the first control example . As shown in FIG. 10, the ECU 113 sequentially selects one of the four driving patterns 1 to 4 shown in FIG. 9 each time the power switch 111 is turned on while the electric vehicle is stopped. . The ECU 113 controls the FC-VCU 103 such that the switching element of the phase indicated by the drive pattern selected according to the flowchart of FIG. 10 performs an on / off switching operation. As a result, the load applied to each phase is equalized due to the rotation of the driving pattern described above, so that the FC-VCU 103 can have high durability and long life.

As described above, the control for equalizing the load of each phase according to the first control example is performed each time the power switch 111 is turned on in a state where the electric vehicle is stopped. This is a simple control in which one of the four is selected in order. In addition to the simple control, the control of the FC-VCU 103 is stabilized because a large control parameter change such as rotation of the driving pattern can be performed before the operation of the FC-VCU 103, not during the operation of the FC-VCU 103. In the flowchart shown in FIG. 10, the ECU 113 selects the drive pattern after the power switch 111 is turned on. However, the ECU 113 selects and stores the drive pattern when the power switch 111 is turned off. When the power switch 111 is turned on, the stored drive pattern may be read. Further, in the diagram shown in FIG. 9, all the driving patterns are limited to one phase, two phases, and four phases, and driving in three phases is not included. In addition to two and four phases, three phases to be driven in the case of three phases may be set.

In addition, the ECU 113 of the first control example may perform the power save control described in the seventh control example or the phase current balance control described in the eighth control example in addition to the above-described control during traveling of the electric vehicle. . Although the load equalization during the running of the electric vehicle is not performed only by the control of the first control example , the load of each phase can be equalized even during the running of the electric vehicle by performing the additional control described above. Of the FC-VCU 103 can have high durability and long life.

In addition, the rotation of the driving pattern described in the first control example , the power save control described in the seventh control example , and the phase current balance control described in the eighth control example suppress concentration of a load on a specific phase. Has a common purpose. In order to more appropriately equalize the load of each phase by combining these controls, it is necessary to avoid competition (hunting) between the controls so that each control functions normally.

The main control parameter in the rotation of the drive pattern described in the first control example is an on / off operation of the power switch 111, and the main control parameter in the power save control described in the seventh control example is the temperature sensor 1091 to 1094. The main control parameter in the phase current balance control described in the eighth control example is the detection value of the phase current sensors 1051 to 1054. As described above, since the main control parameters in these controls are different from each other, the other control is not affected at all.

Further, the power save control described in the seventh control example and the phase current balance control described in the eighth control example are performed while the electric vehicle is running, and the rotation of the drive pattern described in the first control example is performed in the electric vehicle. Is performed while the vehicle is stopped (at the time of start-up), so that the applied scene is completely different.

That is, the main control parameters and control application scenes are used for the rotation of the drive pattern described in the first control example , the power save control described in the seventh control example , and the phase current balance control described in the eighth control example. Therefore, by appropriately combining these controls, the durability and life of the FC-VCU 103 can be further improved.

(Second control example )
When driving the magnetic coupling type FC-VCU 103 shown in FIG. 2 and FIG. 6 in one phase, the ECU 113 of the second control example is the inner one of the phases 1 to 4 arranged in a line on the XY plane. Is driven.

FIG. 11 is a diagram of a second control example showing phases to be driven for each drive pattern in the FC-VCU 103 for each number of operating phases. The ECU 113 of the second control example controls the FC-VCU 103 based on one of the two drive patterns shown in FIG. For example, when the FC-VCU 103 is driven in one phase in the driving pattern 1, the ECU 113 controls the on / off switching of the switching element of phase 2; On / off switching control is performed with a phase difference of degrees, and when driving in four phases, on / off switching control of each of the switching elements of phase 1 to phase 4 is performed with a phase difference of 90 degrees. In the case of two phases, the phase to be driven in the case of one phase and the phase in which the iron core of the reactor and the phase are shared, such as “phase 1 and phase 2” or “phase 3 and phase 4” In other words, two phases of the phase and the magnetically coupled phase are driven. However, when the iron core of each phase reactor shown in FIGS. 7 and 8 drives the independent FC-VCU 203 in two phases, the phase (phase 2 or phase 3) to be driven in the case of one phase, and The phase (phase 3 or phase 2) arranged on the inner side adjacent to the phase is driven. When the FC-VCU 203 shown in FIGS. 7 and 8 is used, driving may be performed in three phases. The number of operating phases of the FC-VCUs 103 and 203 is determined by the ECU 113 based on the input current IFC to the FC-VCU 103.

FIG. 12 is a flowchart illustrating a procedure for selecting a drive pattern of the FC-VCU 103 by the ECU 113 in the second control example . As shown in FIG. 12, the ECU 113 sequentially selects one of the two drive patterns 1 and 2 shown in FIG. 11 each time the power switch 111 is turned on while the electric vehicle is stopped. . The ECU 113 controls the FC-VCU 103 based on the drive pattern selected according to the flowchart of FIG.

As described above, according to the second control example , the phases that are driven when the FC-VCU 103 is driven in one phase are one of the phases 1 to 4 arranged side by side in the example illustrated in FIG. Phase 2 or phase 3 located inside. The reason why the phase 2 or the phase 3 is preferentially used is that the length of the wiring (112, 113, 122, 123) from the phase 2 or the phase 3 to the smoothing capacitors C1 and C2 is the phase 1 or the phase 3. This is because the length from (4) to the smoothing capacitors C1 and C2 is shorter than the length (111, 114, 122, 124). If the wiring is long, the L component increases and the smoothing ability by the smoothing capacitors C1 and C2 decreases. Therefore, when the phase 1 or the phase 4 is selected, the switching ripple due to the operation of the power switch 111 increases. However, as in this control example, the phase 2 or phase 3 having the shortest wiring length to the smoothing capacitors C1 and C2 is preferentially used as the phase for performing voltage conversion, and the wiring length to the smoothing capacitors C1 and C2 is the shortest. If the long phases 1 and 4 are not used, the input / output current of the FC-VCU 103 is sufficiently smoothed by the smoothing capacitors C1 and C2, and the ripple is suppressed. In addition, the noise level applied to the outside of the FC-VCU 103 by the phase 2 and the phase 3 is lower than that of the phase 1 and the phase 4 arranged on the outside. , The noise level is low and the ripple is small due to the shielding effect. Therefore, the ECU 113 preferentially uses phase 2 or phase 3 when driving the FC-VCU 103 in one phase. As a result, it is possible to prevent the load from being concentrated on some of the phases, and to minimize the adverse effect on other electric components provided around. Note that the driving pattern shown in FIG. 11 is limited to one phase, two phases, and four phases, and does not include driving in three phases. In addition to two and four phases, three phases to be driven in the case of three phases may be set.

The first effect of the second control example is that the size of the smoothing capacitors C1 and C2 can be reduced by reducing the ripple of the output current of the FC-VCU 103, so that the FC-VCU 103 can be reduced in weight and size. In addition, as a second effect, the load applied to each phase is equalized, so that the FC-VCU 103 can have high durability and long life. That is, the second control example both the first and second effects can be achieved simultaneously.

Further, similarly to the rotation of the driving pattern described in the first control example , the rotation of the driving pattern described in the second control example is performed by the power saving control described in the seventh control example and the phase current described in the eighth control example. By combining with the balance control, it is possible to further increase the durability and life of the FC-VCU 103. Similar to the first control example, rotation of the driving patterns described in the second control example, to the phase current balance control described power save control and the eighth control example described in the seventh control example, the main control Since double hunting countermeasures are taken depending on the application scene of parameters and control, by appropriately combining these controls, it is possible to further increase the durability and life of the FC-VCU 103.

It should be noted that the rotation of the drive pattern described in the second control example can be applied to other than the four-phase magnetic coupling type multi-phase converter. As a first modified example of the second control example , there is a rotation of a driving pattern in a 2N-phase magnetic coupling type multi-phase converter in which two adjacent phases are magnetically coupled to each other. Note that N is a natural number of 3 or more. For example, in a six-phase magnetic coupling type polyphase converter, as described in the second control example , when driving in one phase, one of phase 3 and phase 4 located at the center of the polyphase converter is used. When driven by two phases, both phases 3 and 4 magnetically coupled to each other are used. When driven by three phases, phase 2 located at the center of the polyphase converter after phase 3 and phase 4 Alternatively, one of phase 5 is used. That is, the phase located at the center of the multi-phase converter and the phase magnetically coupled to the phase may be a drive pattern that is preferentially driven.

It should be noted that the rotation of the drive pattern described in the second control example is applicable to a multi-phase converter in which the number of magnetically coupled phases is other than two. As a second modified example of the second control example , there is a rotation of a drive pattern in an L × M-phase magnetically coupled polyphase converter in which adjacent M phases are magnetically coupled to each other. Note that M is a natural number of 3 or more, and L is a natural number of 1 or more. For example, in a six-phase magnetic coupling type multi-phase converter, a phase 3 located at the center of the multi-phase converter is used as the first drive pattern when driving in one phase, and a phase 3 is used in driving in two phases. Of the phases 1 and 2 magnetically coupled to each other, the phase 2 close to the center of the polyphase converter is used. When driven in three phases, phases 1 to 3 are used. When driven in four phases, the phase 1 is used. In addition to .about.3, phase 4 located at the center of the polyphase converter is used. As the second drive pattern, when driving in one phase, phase 4 located at the center of the polyphase converter is used. When driving in two phases, phase 4 and phase 6 magnetically coupled to each other are used. When the phase 5 close to the center of the polyphase converter is used and phases are driven by three phases, phases 4 to 6 are used. When driven by four phases, the phase is located at the center of the polyphase converter in addition to phases 4 to 6. Use phase 3. The first and second drive patterns are rotated.

Further, it should be noted that the rotation of the drive pattern described in the second control example can be applied to a polyphase converter that is not magnetically coupled. As a third modified example of the second control example , there is a rotation of a drive pattern in a polyphase converter that is not magnetically coupled. In the third modification, since all phases are not magnetically coupled to each other, the phase located at the center of the multiphase converter is preferentially used each time the number of phases to be driven increases.

(Third control example )
The ECU 113 of the third control example includes an input current IFC to the FC-VCU 103 which is also an output current of the fuel cell 101, an input voltage V1 of the FC-VCU 103 which is also an output voltage of the fuel cell 101, and an FC-VCU 103 which is a target value. The number of operating phases of the FC-VCU 103 is determined based on only the input current IFC from a loss map created in advance based on the output voltage V2 of the FC-VCU 103. In the following description, “output voltage V2 / input voltage V1” is referred to as a boost rate of FC-VCU 103.

  FIG. 13 is a graph showing the loss η total_N in the FC-VCU 103 with respect to the input current IFC for each number N of operating phases when the input power (= IFC × V1) of the FC-VCU 103 is fixed. FIG. 14 is a graph showing the loss in the FC-VCU 103 with respect to the boost rate when the input power is constant and the FC-VCU 103 is driven with a predetermined number of phases. As shown in FIG. 13, the magnitude of the loss in the FC-VCU 103 differs depending on the input current IFC, and also differs depending on the number N of operating phases. For this reason, the number N of operating phases that minimizes the loss when the input power is constant is obtained from the input current IFC. However, as shown in FIG. 14, the magnitude of the loss in the FC-VCU 103 differs depending on the boosting rate (= output voltage V2 / input voltage V1). In a commercial power system or the like that is a constant power source, the number of operating phases can be appropriately changed based only on FIG. 13 and FIG. 14, but as described later, an IV characteristic in which an output voltage fluctuates according to an output current. In a power supply having the above, the number of operating phases cannot be appropriately changed unless this IV characteristic is considered.

Therefore, in the present control example , the loss at the FC-VCU 103 with respect to the input current IFC is derived in advance for each output voltage V2 of the FC-VCU 103, and a loss map is created for each number N of operating phases. In this control example , the FC-VCU 103 shown in FIG. 2 and FIG. 6 is driven in one of two phases, one phase, two phases, and four phases for the reason described later. Create each loss map. The horizontal axis of each loss map shown in FIG. 15 indicates the input current IFC, and the vertical axis indicates the output voltage V2. The loss in the FC-VCU 103 corresponding to each input current IFC and each output voltage V2 extracted from a predetermined range. Values are listed. The input current IFC is represented by I1 to I20, respectively, and these I1 to I20 are values provided at equal intervals. The output voltage V2 is represented by V2_1 to V2_21, and these V2_1 to V2_21 are values provided at equal intervals. Note that a relationship of “output voltage V2 = boost rate × input voltage V1 (3)” is established. The loss described in each of the loss maps shown in FIG. 15 and FIG. 17 described later is not an actual loss value (W) but a value for explaining the magnitude relationship between the loss values under each condition. Note that this is the normalized loss value of

  Since the input voltage V1 has a predetermined relationship with the input current IFC based on the IV characteristics of the fuel cell 101 shown in FIG. 16, it can be derived from the input current IFC. Therefore, assuming that the input voltage V1 is a coefficient in the above equation (3), the output voltage V2 shown in FIG. 15 is a variable that indirectly indicates the boost rate.

In each loss map of FIG. 15, among the three loss values corresponding to the same input current IFC and the same output voltage V2, the cell having the smallest value, in other words, the cell having the highest efficiency is hatched. In this control example , a combined loss map shown in FIG. 17 is created by extracting minimum loss values hatched by the three loss maps shown in FIG. 15, and the number of operating phases of the FC-VCU 103 is calculated based on the combined loss map. Is set, the threshold value of the input current IFC is set.

  As shown in the combined loss map of FIG. 17, when the number of operating phases at which the loss value becomes minimum differs depending on the output voltage V2 even with the same input current IFC, the output voltage V2 of the different The number of operating phases with the largest number of cells having the minimum loss value corresponding to each is set to the number of operating phases for performing voltage conversion. For example, in the example shown in FIG. 17, when the input current IFC is I12 (A), the number of cells having the minimum loss value corresponding to each of the different output voltages V2 is three when the number of operating phases is four. Is 18 in two phases, the number of operating phases when the input current IFC is I12 (A) is set to two phases, and the threshold value of the input current IFC for switching between two phases and four phases is I12 (A). And I13 (A). Further, a combined loss map may be created by removing the number of operating phases having the smallest number of cells having the smallest loss value. The threshold value set based on the combined loss map is not limited to the above-described setting according to the number of cells, but may be set according to the magnitude of the loss value of each operating phase at a predetermined output voltage V2. . The predetermined output voltage V2 is, for example, an average value or a median value of the range of the output voltage V2 in the loss map. If the predetermined output voltage V2 is V2_11, the threshold value of the input current IFC for switching between one phase and two phases is set to a value IFCa between I5 (A) and I6 (A), and two phases and four phases are set. The threshold value of the input current IFC to be switched is set to a value IFCb between I12 (A) and I13 (A).

  Note that the threshold value of the input current IFC for switching the number of operating phases may be provided with hysteresis when the input current IFC increases and when the input current IFC decreases. For example, the threshold value IFCb, which is a point at which the two-phase and the four-phase are switched, is set to I13 (A) when the input current IFC rises and the two-phase is switched to the four-phase. When switching from two phases to two phases, it is set to I13-Δ (A). By providing this hysteresis, control conflict can be eliminated.

  Although the loss map shown in FIG. 15 and the combined loss map shown in FIG. 17 are maps of loss values, an efficiency map may be used instead of a loss value. In this case, as the threshold value of the input current IFC, a combined efficiency map based on the number of operating phases having the highest efficiency is used.

The threshold value IFCb having the smaller absolute value of the absolute value of the rising speed of the command value of the input current IFC and the absolute value of the falling speed of the command value of the input current IFC is set to I13 (A). Is preferably set to I13-Δ (A). This is because the smaller the absolute value is, the longer the IFC belongs to the vicinity of the threshold value, so that the number of operating phases can be more appropriately switched and the loss is reduced. In this control example , since the absolute value of the rising speed of the command value of the input current IFC is smaller than the absolute value of the falling speed of the command value of the input current IFC, the input current IFC rises and changes from two phases to four phases. In the case of switching, the threshold value IFCb is set to I13 (A), and in the case of switching from four phases to two phases due to the fall of the input current IFC, the threshold value IFCb is set to I13-Δ (A). You.

The ECU 113 of this control example uses the threshold values IFCa and IFCb of the input current IFC, which are the switching points of the number of operating phases according to the composite loss map shown in FIG. The number of operating phases of the FC-VCU 103 is determined based on only the current IFC or only the input current IFC obtained from the detection values of the phase current sensors 1051 to 1054. The loss map shown in FIG. 15 and the combined loss map shown in FIG. 17 are created in advance by a computer different from the ECU 113.

As described above, the value required for the EC 113 of the third control example to determine the number of operating phases of the FC-VCU 103 is only the input current IFC to the FC-VCU 103, and the EC 113 has the threshold values IFCa, The number of operating phases can be determined by simple control using IFCb as a reference value. As described above, since a value other than the input current IFC is not required to determine the number of operating phases, efficient and appropriate switching control of the number of operating phases is possible. As a result, even if the output of the fuel cell 101 changes, the FC-VCU 103 operates efficiently.

In the above description, the number of operating phases of the magnetic coupling type FC-VCU 103 shown in FIGS. 2 and 6 has been described as one, two, or four. However, each phase shown in FIGS. When the FC-VCU 203 in which the iron cores of the reactors are independent is used, one phase, two phases, two phases, and three phases are obtained according to a combined loss map based on four loss maps of one to four phases including three phases. Set each threshold, which is the phase and the switch point between three and four phases. When driving the FC-VCU 103 in a plurality of phases, the ECU 113 of the third control example may perform the phase current balance control described in the eighth control example .

  In the above description, in FIGS. 15 and 17, the loss under each condition is calculated at a predetermined voltage (V) interval in V2_1 to V2_21 (V), which is the range of the output voltage V2 required for the FC-VCU 103. However, as a modified example, the loss under each condition may be calculated only with the average value in the range of the output voltage V2 required for the FC-VCU 103, and the number of operating phases for the input current IFC may be determined based on this. In the combined loss map shown in FIG. 17, it is possible to obtain the threshold value of the input current IFC by focusing only on the average value V2_11 (V) of the range of the output voltage V2 required for the FC-VCU 103. is there. According to this modification, not only can the number of operating phases of the FC-VCU 103 be changed in terms of efficiency, but also the number of steps required for control construction relating to the number of operating phases can be significantly reduced.

In the present control example , the case where the number of operating phases is changed based on only the input current IFC has been described. However, in order to perform voltage conversion with higher efficiency, as a modification of the present control example , in addition to the input current IFC, the output voltage The number of operating phases may be changed based on V2. In this modification, when the input current IFC is I12 (A) and the output voltage V2 is V2_1 to V2_3 (V), driving is performed in four phases, the input current IFC is I12 (A), and the output voltage V2 is V2_4 to V2_21 (V). In ()), two-phase driving is performed.

(Fourth control example )
The ECU 113 of the fourth control example prohibits an odd-numbered phase other than one as the number of operating phases of the magnetic coupling type FC-VCU 103 illustrated in FIGS. 2 and 6.

FIG. 18 is a diagram illustrating a fourth control example in which phases to be driven for each drive pattern in the FC-VCU 103 are shown for each number of operating phases. The ECU 113 of the fourth control example controls the FC-VCU 103 based on one of the four drive patterns shown in FIG. For example, when the FC-VCU 103 is driven in one phase in the driving pattern 1, the ECU 113 controls the on / off switching of the switching element of the phase 1, and when driven in two phases, the switching element of the phase 1 and the phase 2 is 180. On / off switching control is performed with a phase difference of degrees, and when driving in four phases, on / off switching control of each of the switching elements of phase 1 to phase 4 is performed with a phase difference of 90 degrees. In the case of two phases, the phase to be driven in the case of one phase and the phase in which the iron core of the reactor is shared with the phase to be driven, such as “phase 1 and phase 2” or “phase 3 and phase 4” Drives two phases.

FIG. 19 is a diagram illustrating temporal changes in phase currents IL1 to IL4 flowing through the respective phases when the FC-VCU 103 is driven in four phases. As shown in FIG. 19, when the FC-VCU 103 is driven in four phases, the change in the amplitude of the phase currents IL1 to IL4 is determined by the phase current balance control described in the eighth control example . It is even because it is. Similarly, when the FC-VCU 103 is driven in two phases, changes in the amplitudes of the phase currents IL1 and IL2 when driving the phases 1 and 2 and the phase currents IL3 and IL4 when driving the phases 3 and 4 are performed. Are equal.

FIG. 20 is a diagram showing temporal changes in phase currents IL1 to IL4 flowing in the respective phases when driving FC-VCU 103 in three phases. Even if the input current of each phase is balanced by the phase current balance control described in the eighth control example , if the number of operating phases is changed from four to three, the phase current IL4 flowing in phase 4 decreases. As a result, the magnetic flux 4 acting in the direction to cancel the magnetic flux 3 of the iron core Cob shown in FIG. 6 decreases, and the phase current IL3 of the phase 3 that forms a pair of the reverse-winding magnetic coupling increases. As a result, as shown in FIG. 20, the change in the amplitude of the phase current IL3 is larger than the change in the amplitude of the phase currents IL1 and IL2, and the load on the phase 3 is higher than in the other phases. Therefore, the ECU 113 of the present control example prohibits driving of the FC-VCU 103 in odd-numbered phases except for one phase. The same phase current imbalance occurs when the number of operating phases is changed from two to three.

If driving in one phase is also prohibited, as shown in FIG. 5, the energy efficiency of the FC-VCU 103 decreases particularly when the input current IFC is low. Therefore, even in the case of the magnetic coupling type FC-VCU 103, the ECU 113 of this control example permits one-phase driving.

As described above, according to the fourth control example , as the number of operating phases of the magnetic coupling type FC-VCU 103, odd phases other than one are prohibited. For this reason, the concentration of the load on one phase can be prevented, and the life and durability of the FC-VCU 103 can be extended. Further, when the driving in the odd-numbered phases is prohibited, one of the sets of phases sharing the iron core is not driven except for the case of the number of operating phases being 1, so that the amplitude of the phase current of the driven phase changes evenly. And the control of the FC-VCU 103 is stabilized. Furthermore, since the amplitudes of the phase currents of the driving phases are uniform, the ripple of the output current of the FC-VCU 103 is reduced by the above-described interleave control, the size of the smoothing capacitor C2 can be reduced, and the weight of the FC-VCU 103 can be reduced.・ Miniaturization is possible.

In the fourth control example , the case where two adjacent phases are magnetically coupled to each other has been described. However, as a modified example of this control example , in the case where adjacent N phases are magnetically coupled to each other, Only one phase and a multiple of N are used as the number of operating phases. Excluding one phase, it is prohibited to use only a part of the N phases magnetically coupled to each other as the number of operating phases. Note that N is a natural number of 3 or more.

  Further, in the above description, one-phase operation is exceptionally permitted in order to suppress a decrease in the energy efficiency of the FC-VCU 103 particularly in a state where the input current IFC is low. One-phase operation may be prohibited in order to increase the durability and the service life.

(Fifth control example )
When switching the number of operating phases of the FC-VCU 103, the ECU 113 of the fifth control example changes the duty ratio of the on / off switching control for the switching element of the phase to start driving or the phase to stop driving stepwise and continuously. .

FIG. 21 shows the duty ratios D1 and D2 of the on / off switching control for the switching elements of phase 1 that continues driving and phase 2 that starts driving when the number of operating phases of the FC-VCU 103 is switched from one phase to two phases. FIG. 14 is a diagram of a fifth control example illustrating an example of changes over time of the phase currents IL1 and IL2 and the input current IFC. As shown in FIG. 21, when newly driving the phase 2 in addition to the phase 1 being driven, the ECU 113 of this control example sets a phase number switching period Ti from one phase to two phases. During this period Ti, while the duty ratio D1 of the on / off switching control for the phase 1 switching element that continues driving is fixed, the duty ratio D2 of the on / off switching control for the phase 2 switching element that starts driving is gradually increased. increase. Note that the final duty ratio of the phase 2 after the phase number switching period Ti is the duty ratio of the phase 1.

If the ECU 113 starts driving the phase 2 at a duty ratio corresponding to a desired boost rate in the FC-VCU 103 without setting the number-of-phases switching period Ti, the input current IFC is reduced as shown by a dashed line in FIG. fluctuate. This fluctuation of the input current IFC not only impairs control stability, but also hinders an increase in the size of the smoothing capacitors C1 and C2, and a reduction in the weight and size of the FC-VCU 103. However, as in the present control example , by gradually increasing the duty ratio of the phase to start driving toward the duty ratio of the phase being driven, the phase current flowing through the phase to start driving gradually changes. , The fluctuation of the input current IFC can be suppressed.

On the other hand, in order to switch the number of operating phases of the FC-VCU 103 from two phases to one phase, for example, when stopping the driving of the phase 2, the ECU 113 of the present control example , as shown in FIG. A phase number switching period Td for each phase is set, and during this period Td, the duty ratio D3 of the on / off switching control for the phase 1 switching element that continues driving is fixed and the phase 2 switching element for which the driving is stopped is stopped. The duty ratio D4 of the on / off switching control is reduced stepwise to zero. FIG. 22 shows the duty ratios D3 and D4 of the on / off switching control for the driving phase 1 and the driving stop phase 2 when switching the number of operating phases of the FC-VCU 103 from two to one, and the phase currents IL1 and IL4. FIG. 4 is a diagram illustrating an example of a change with time of IL2 and an input current IFC.

  When the number of operating phases is increased as shown in FIG. 21, the load on one of the driving phases (hereinafter referred to as “driving phase”) is reduced, so that the control stability of the FC-VCU 103 is improved, and In addition, the reduction of the load contributes to high durability and long life of the FC-VCU 103. On the other hand, when the number of operating phases is reduced as shown in FIG. 22, the load applied to one driving phase increases, so that the control stability of the FC-VCU 103 decreases and the increase in the load decreases. Hinders high durability and long service life. As described above, since the control stability of the FC-VCU 103 is reduced when the number of operating phases is reduced, the ECU 113 sets the phase number switching period Td set when reducing the number of operating phases to the number of operating phases. The change rate of the duty ratio D2 is set smaller than that in FIG. 21 by setting it longer than the phase number switching period Ti set when increasing.

  The examples shown in FIGS. 21 and 22 described above are cases where the number of operating phases is switched between one phase and two phases, but the same applies to the case where the number of operating phases is switched between two phases and four phases. However, as shown in FIG. 23, when switching the number of operating phases based on thresholds IFCa and IFCb of input current IFC for switching the number of operating phases predetermined based on the loss generated in FC-VCU 103, ECU 113 The larger the amount of change in the phase current flowing through the phase that continues driving or the amount of change in the phase current flowing through the phase that starts or stops driving, which is the driving phase accompanying the switching of the number of operating phases, the greater the number of phase switching periods Ti and Td Is set longer to reduce the duty ratio change rate. In the example shown in FIG. 23, the change amount of the phase current in the drive phase when switching between 1 phase and 2 phases is “IFCa / 2”, and the change amount of the phase current in the drive phase when switching between 2 phases and 4 phases. Is "IFCb / 2-IFCb / 4". The amount of change in the phase current when the number of operating phases is discontinuously changed, such as switching between two phases and four phases, may be larger than the amount of change in the phase current when the number of operating phases is continuously changed. High. Therefore, the phase number switching period at the time of discontinuous switching of the number of operating phases is set longer than at the time of continuous switching.

  Note that the threshold of the input current IFC, which is the point at which the number of operating phases is switched, may be provided with hysteresis when the input current IFC rises and when it falls. In this case, the amount of change in the phase current in the drive phase due to the change in the number of operating phases is different depending on whether the input current IFC increases or decreases.

FIG. 24 is a flowchart illustrating an operation performed by the ECU 113 of the fifth control example when the number of operating phases of the FC-VCU 103 is switched. As shown in FIG. 24, the ECU 113 determines whether or not to switch the number of operating phases (step S501). If the number of operating phases is to be switched, the process proceeds to step S503. In step S503, the ECU 113 sets the number-of-phases switching period T based on the increase / decrease in the number of operating phases and the amount of change in the phase current in the drive phase before and after the switching of the number of operating phases. At this time, the ECU 113 sets the phase number switching period T to be longer when the number of operating phases is reduced than when it is increased, and the larger the amount of change in the phase current in the driving phase before and after the switching of the number of operating phases, the longer the phase number switching period T. Set longer. Further, the ECU 113 sets a longer phase number switching period T when the number of operating phases is switched discontinuously than when the number of operating phases is switched continuously.

  Next, the ECU 113 acquires the duty ratio D of the phase in which the driving is continued (step S505). Next, the ECU 113 sets the count value t indicating the time to 0 (step S507). Next, the ECU 113 sets a value obtained by adding the control period Δt to the count value t as a new count value t (step S509). Next, when increasing the number of operating phases while keeping the duty ratio D of the phase in which the driving is continued fixed, the ECU 113 switches on / off the switching element of the phase in which the driving is started at a duty ratio of (t / T) × D. When the control is performed to reduce the number of operating phases, on / off switching control is performed on the switching element of the phase whose driving is stopped at a duty ratio of D− (t / T) × D (step S511). Next, the ECU 113 determines whether or not the count value t is equal to or longer than the phase number switching period T (t ≧ T) (step S513). If so, the process returns to step S509.

As described above, when switching the number of operating phases of the FC-VCU 103, the ECU 113 of the fifth control example gradually changes the duty ratio of the on / off switching control for the switching element of the phase to start driving or the phase to stop driving. By changing to the above, the phase current flowing through the phase for starting the driving or the phase for stopping the driving gradually changes, so that the fluctuation of the input current IFC when the number of operating phases is switched can be suppressed. In addition, although the control stability of the FC-VCU 103 at the time of reducing the number of operation phases is reduced, the control stability is set to a longer phase number switching period in accordance with the reduction. Also, the variation of the input current IFC at the time of switching the number of operating phases can be suppressed. Similarly, the control stability decreases as the amount of change in the phase current of the drive phase at the time of switching the number of operating phases increases. The fluctuation of the input current IFC can be suppressed. Also, when the number of operating phases is switched discontinuously, the change amount of the phase current is large and the control stability is likely to be reduced. Therefore, by setting a longer phase number switching period in this case, the switching of the number of operating phases is performed. The fluctuation of the input current IFC at the time can be suppressed. Therefore, the weight and size of the FC-VCU 103 due to the increase in the size of the smoothing capacitors C1 and C2 can be suppressed while ensuring control stability.

  The example shown in FIG. 23 shows the case where the number of operating phases of the magnetic coupling type FC-VCU 103 shown in FIGS. 2 and 6 is one, two, or four. When using the FC-VCU 203 in which the iron core of the reactor of each phase shown is independent, the number of operating phases of 1 to 4 phases including 3 phases is used. In this case, as shown in FIG. 25, the number of operating phases is switched based on thresholds IFCaa, IFCbb, and IFCcc of input current IFC for switching the number of operating phases predetermined based on a loss generated in FC-VCU 103. The ECU 113 sets the phase number switching periods Ti and Td to be longer as the amount of change in the phase current flowing through the driving phase accompanying the switching of the number of operating phases is longer, and reduces the rate of change in the duty ratio.

(Sixth control example )
The ECU 113 of the sixth control example controls the frequency of the switching signal (hereinafter referred to as “switching frequency”) based on the input current IFC to the FC-VCU 103 such that the ripple of the input / output current of the smoothing capacitors C1 and C2 is equal to or less than the threshold. ) To synchronize the change in the number of operating phases of the FC-VCU 103 with the change in the setting of the switching frequency.

FIG. 26 shows the case where the number of operating phases of the FC-VCU 103 controlled at the switching frequency f is one, the number of operating phases of the FC-VCU 103 controlled at the switching frequency f / 2 is one, and the switching frequency f FIG. 4 is a diagram illustrating an example of a change over time of the output current and the input current IFC of the FC-VCU 103 when the number of operating phases of the FC-VCU 103 controlled at / 2 is two phases and the above-described interleave control is performed. As shown in the example on the left side of FIG. 26, when the ECU 113 drives the FC-VCU 103 in one phase and controls the switching elements of the driving phase to be turned on / off at the switching frequency f, the output current and the input current IFC of the FC-VCU 103 are changed. Becomes the same “f” as the switching frequency f. Here, if the number of operating phases is changed to the switching frequency f / 2 while maintaining one phase, each frequency of the output current and the input current IFC of the FC-VCU 103 becomes “f / 2” which is the same as the switching frequency f / 2. This frequency f or f / 2 is provided at the resonance frequency of the circuit including the smoothing capacitor C1 provided on the input side of the FC-VCU 103 and the circuit provided upstream of the FC-VCU 103, or provided at the output side of the FC-VCU 103. The resonance frequency of the circuit including the smoothing capacitor C2 and the circuit provided downstream of the FC-VCU 103 is not preferable because the ripples of the output current and the input current IFC of the FC-VCU 103 increase. In this control example , description will be made assuming that the frequency f / 2 is the resonance frequency.

  When the switching frequency is set low especially when the input current IFC is low and the FC-VCU 103 is driven in one phase, the input current IFC has a discontinuous waveform including a period in which the value is 0 (zero-crossing). In some cases. Such a discontinuous waveform of the input current IFC is not preferable because it reduces control stability of the FC-VCU 103.

  As described above, if the switching frequency when the FC-VCU 103 is driven in one phase is low, problems such as an increase in ripples and a decrease in control stability occur. Is desirable. However, if this high frequency is applied to two or more phases, the switching loss in the entire FC-VCU 103 increases, and another problem such as overheating of the FC-VCU 103 due to heat generation of the switching element may occur. Therefore, it is desirable that the switching frequency of the FC-VCU 103 be set lower as the number of operating phases increases. In FIG. 26, when the FC-VCU 103 is driven in two phases as shown in the example on the right side with respect to the example on the left side, on / off switching control of the switching elements of the driving phase is performed at the switching frequency f / 2. At this time, the frequency of the output current of the FC-VCU 103 is the same as the frequency shown in the example on the left because the FC-VCU 103 is interleaved, and the resonance frequency f / 2 can be avoided.

FIG. 27 is a diagram illustrating a relationship between the input current IFC, the switching frequency, the number of operating phases, and the frequency of the input / output current when the ECU 113 of the sixth control example controls the FC-VCU 103. The ECU 113 of this control example determines the switching frequency and the number of operating phases of the FC-VCU 103 based on the relationship shown in FIG. That is, the ECU 113 sets a switching frequency according to the input current IFC to the FC-VCU 103, and switches the number of operating phases in synchronization with the change in the setting of the switching frequency. Note that the switching frequency f when the FC-VCU 103 is driven in one phase is set to a value at which the amplitude of the ripple of the output current and the input current IFC of the FC-VCU 103 is equal to or smaller than the threshold. When performing interleave control during multi-phase operation, the switching frequency is set according to the input current IFC so that the value obtained by multiplying the switching frequency by the number of operating phases does not become the resonance frequency. Preferably, the switching frequency according to the input current IFC is set so that the frequency of the output current does not change even when the number of operating phases is changed.

Note that, as in the present control example , the change in the number of operating phases is not synchronized with the change in the setting of the switching frequency. For example, as shown in FIG. If the number of operating phases is changed based on this, the FC-VCU 103 can be driven in a state where the energy efficiency is always high. However, depending on the value of the input current IFC, the frequency of the input / output current of the FC-VCU 103 becomes the resonance frequency f / 2, and the ripple increases.

As described above, in the sixth control example , the frequency of the switching signal (hereinafter referred to as “the frequency of the switching signal” based on the input current IFC to the FC-VCU 103 such that the ripple due to the resonance at the input / output side of the FC-VCU 103 is equal to or less than the threshold. Is set, and the number of operating phases of the FC-VCU 103 is changed in synchronization with the setting change of the switching frequency based on the input current IFC. Thus, even if the setting of the FC-VCU 103 is changed, if the software is changed without changing the hardware configuration, the occurrence of resonance on the input / output side of the FC-VCU 103 can be prevented, Control stability of the FC-VCU 103 can be improved.

  Further, the switching frequency set when the input current IFC is low is set to a value high enough not to cause a problem of overheating of the FC-VCU 103, so that the input current IFC has a current level that has a continuous waveform without zero crossing. The lower limit can be lowered. That is, it is possible to widen the range of the input current in which the control stability equal to or higher than the predetermined level can be secured. Furthermore, since the output current of the FC-VCU 103 and the amplitude of the ripple of the input current IFC are equal to or smaller than the threshold value, it is possible to avoid an increase in the size of the smoothing capacitors C1 and C2, and to reduce the size and weight of the FC-VCU 103. Become.

  The example shown in FIG. 27 shows a case where the number of operating phases of the magnetic coupling type FC-VCU 103 shown in FIGS. 2 and 6 is one, two, or four. When using the FC-VCU 203 in which the iron core of the reactor of each phase shown is independent, the number of operating phases of 1 to 4 phases including 3 phases is used. In this case, the relationship between the input current IFC and the switching frequency and the number of operating phases is shown in FIG. Further, the threshold value of the input current IFC for switching the switching frequency and the number of operating phases may be provided with hysteresis when the input current IFC increases and when the input current IFC decreases. For example, the threshold value IFCa shown in FIGS. 27 and 29, which is a point at which one-phase and two-phase are switched, is different from the value set when the input current IFC rises to switch from one-phase to two-phase. When the IFC drops and switches from two phases to one phase, a value lower than this value is set. By providing this hysteresis, control conflict (hunting) can be eliminated.

(Seventh control example )
When the temperature of the FC-VCU 103 exceeds the threshold value, the ECU 113 of the seventh control example increases the number of operating phases of the FC-VCU 103 to a number larger than the current number of phases.

The ECU 113 of this control example prevents overheating of the FC-VCU 103 when at least one of the temperatures T1 to T4 detected by the temperature sensors 1091 to 1094 (hereinafter, simply referred to as “temperature T”) exceeds a threshold th1. For this purpose, control for reducing the input current IFC that is the output current of the fuel cell 101 (hereinafter referred to as “power save control”) is performed. However, when the ECU 113 determines the number of operating phases of the FC-VCU 103 based on the input current IFC based on the graph shown in FIG. 30, the power saving control reduces the input current IFC to reduce the number of operating phases. If it is reduced, as shown in FIG. 31, the phase current flowing through the driving phase increases, and conversely, there is a possibility that the temperature T of the FC-VCU 103 may further increase. The power save control is control performed on the FC-VCU 103 by changing the duty ratio of the driving phase, but may be output control performed on the fuel cell 101.

Even in the case where the power save control is performed when the temperature T exceeds the threshold value th1, the ECU 113 of the present control example determines the number of operating phases of the FC-VCU 103 regardless of the input current IFC, as shown in FIG. Increase the number of phases before power save control. In the example shown in FIG. 32, when the temperature T exceeds the threshold th1 when the FC-VCU 103 is driven in two phases, the power save control is performed and the number of operating phases of the FC-VCU 103 is changed to four phases. I do. As a result, the phase current IL flowing through each phase of the FC-VCU 103 decreases and the load applied to each phase is reduced, so that the temperature T of the FC-VCU 103 decreases.

The ECU 113 of this control example continues the state in which the number of operating phases of the FC-VCU 103 is increased by performing the power save control for a predetermined time τ or more. That is, the ECU 113 prohibits the stop of the power save control and the change of the number of operating phases before the predetermined time τ has elapsed. If the temperature T falls below the threshold th2 after the lapse of the predetermined time τ, the ECU 113 stops the power save control and changes the number of operating phases according to the input current IFC after the stop of the power save control. Note that the threshold value th2 is a value less than the threshold value th1.

FIG. 33 is a flowchart illustrating an operation performed by the ECU 113 of the seventh control example when the temperature of the FC-VCU 103 exceeds a threshold value. As shown in FIG. 33, the ECU 113 determines whether or not the temperature T has exceeded the threshold th1 (T> th1) (step S701), and if T> th1, proceeds to step S703. In step S703, the ECU 113 starts the power save control. Next, the ECU 113 increases the number of operating phases of the FC-VCU 103 from the number of phases before power save control (step S705). When increasing the number of operating phases, the ECU 113 sets the phase number switching period as described in the fifth control example , and increases the duty ratio of the phase to start driving stepwise and continuously. However, the phase number switching period set in step S705 is set to be shorter than the phase number switching period when simply increasing the number of operating phases without performing power save control when the temperature of the FC-VCU 103 is equal to or lower than the threshold value. . As a result, the increase in the number of operating phases performed in step S705 is completed quickly.

  Next, the ECU 113 sets the count value t indicating the time to 0 (step S707). Next, the ECU 113 sets a value obtained by adding the control period Δt to the count value t as a new count value t (step S709). Next, the ECU 113 determines whether or not the count value t is equal to or longer than a predetermined time τ (t ≧ τ) (step S711). If t ≧ τ, the process proceeds to step S713, and if t <τ, the process proceeds to step S713. It returns to S709. In step S713, the ECU 113 determines whether or not the temperature T is lower than the threshold value th2 (T <th2). If T <th2, the process proceeds to step S715. In step S715, the ECU 113 stops the power save control started in step S703. Next, the ECU 113 changes the number of operating phases according to the input current IFC after stopping the power save control (step S717).

As described above, according to the seventh control example , when the temperature of the FC-VCU 103 exceeds the threshold value and the power save control is performed, the number of operating phases of the FC-VCU 103 is set to a phase larger than the current number of phases. By increasing the number, the load on the driving phase is reduced. For this reason, while the drive of the FC-VCU 103 is maintained, the temperature rise before the FC-VCU 103 reaches the overheated state can be suppressed, and the normal state can be maintained.

The example illustrated in FIG. 32 illustrates a case where the number of operating phases of the magnetic coupling type FC-VCU 103 illustrated in FIGS. 2 and 6 is one, two, or four. As shown in the fourth control example , in the magnetic coupling type FC-VCU 103, it is preferable to use only a part of a plurality of phases magnetically coupled to each other in order to avoid concentration of a load on some phases. Absent. This is because even if the number of operating phases is increased to reduce the load on the driving phase, the load is concentrated on some phases, and the possibility of the FC-VCU 103 becoming overheated cannot be eliminated.

  On the other hand, when using the FC-VCU 203 in which the iron core of each phase reactor shown in FIGS. 7 and 8 is independent, the number of operating phases of 1 to 4 phases including 3 phases is used. In this case, when the temperature T exceeds the threshold th1 when the FC-VCU 203 is driven in two phases, power save control is performed, and the number of operating phases of the FC-VCU 103 is increased to three phases or four phases. Change to phase. Further, in any of the magnetic coupling type FC-VCU 103 and the non-magnetic coupling type FC-VCU 203, the ECU 113 performs the maximum operation regardless of the number of operation phases when the temperature T exceeds the threshold th1. The number of phases may be changed. By changing to the maximum number of operation phases, the load applied to the drive phase can be reduced to the maximum, the possibility that the FC-VCU 103 will be overheated can be eliminated earlier, and the normal state can be maintained.

In the examples shown in FIGS. 2 and 7, the temperature sensors 1091 to 1094 are provided only in the vicinity of the switching element. However, other parts inside the FC-VCUs 103 and 203 such as diodes and reactors L1 to L4, and fuel Temperature sensors may be provided outside the FC-VCUs 103 and 203 such as the battery 101 and the smoothing capacitors C1 and C2, and the power save control described in the present control example may be performed based on the temperature detected by the temperature sensors.

(Eighth control example )
When at least one of the phase current sensors 1051 to 1054 or the current sensor 105 has failed, the ECU 113 of the eighth control example performs appropriate control according to the failure state. Note that the ECU 113 determines the failure of the current sensor 105 and the phase current sensors 1051 to 1054. Various known methods can be used to determine the failure of the current sensor 105 and the phase current sensors 1051 to 1054. For example, when using the method of determining a sticking fault, an intermediate sticking fault, and a sticking fault disclosed in Japanese Patent Application Laid-Open No. Hei 10-253682, the ECU 113 determines that a signal indicating a voltage corresponding to the detected current value is within a specified range. If a state representing an outside value has continued for a predetermined time or longer, it is determined that a malfunction has occurred.

In this control example , when all of the current sensor 105 and the phase current sensors 1051 to 1054 are normal, the value of the input current IFC to the FC-VCU 103 detected by the current sensor 105 is the number of operating phases of the FC-VCU 103 by the ECU 113. Is used to determine The values of the phase currents IL1 to IL4 detected by the phase current sensors 1051 to 1054 are used by the ECU 113 to perform phase current balance control. In the phase current balance control, each drive is performed such that each phase current in the drive phase becomes the target value by setting a value obtained by dividing the sum of the moving average values of the phase currents IL1 to IL4 by the number of operating phases of the FC-VCU 103 as the target value. This refers to control for increasing or decreasing the duty ratio of a switching signal for a phase.

The switching control of the number of operating phases is performed based on the input current IFC to the FC-VCU 103 or the total value of the phase currents IL1 to IL4, as described in the third control example . However, the total value of the phase currents IL1 to IL4 does not always indicate the true value of the input current to the FC-VCU 103 due to the phase error of each phase due to a product error of the phase current sensor or interleave control. Therefore, it is preferable to use the input current IFC to the FC-VCU 103. On the other hand, in order to perform the phase current balance control, each value of the phase currents IL1 to IL4 is necessary, so the phase current sensors 1051 to 1054 are used. Either control can prevent the load from being concentrated on some phases.

FIG. 34 is a diagram illustrating a current value for determining the number of operating phases, a current value for phase current balance control, and whether or not power save control is performed for each of different states of the current sensor 105 and the phase current sensors 1051 to 1054. It is a figure of 8 control examples . As shown in FIG. 34, when at least one of the phase current sensors 1051 to 1054 fails, the number of operating phases of the FC-VCU 103 is equal to the input current IFC to the FC-VCU 103 detected by the current sensor 105 without changing from the normal state. And the phase current balance control is not performed. When the current sensor 105 fails, the number of operating phases of the FC-VCU 103 is determined based on the sum of the phase currents IL1 to IL4 detected by the phase current sensors 1051 to 1054, and the phase current balance control is determined to be normal. This is performed based on the phase currents IL1 to IL4 detected by the phase current sensors 1051 to 1054 without any change.

  In addition, when at least one of the phase current sensors 1051 to 1054 fails or when the current sensor 105 fails, control for reducing the input current IFC that is the output current of the fuel cell 101 (hereinafter referred to as “power save control”). ) Is performed. The power save control is control performed on the FC-VCU 103 by changing the duty ratio of the driving phase, but may be output control performed on the fuel cell 101. The power save control performed when at least one of the phase current sensors 1051 to 1054 has failed is performed in order to supplement control stability that is reduced by not performing the phase current balance control. The power save control performed when the current sensor 105 has failed is based on the control cycle based on the sum of the phase currents IL1 to IL4 for determining the number of operating phases of the FC-VCU 103 and the phase currents IL1 to IL4. This is performed in order to complement the control stability that is lowered by synchronizing with the phase current balance control cycle. In addition, as described above, the phase current of each phase is different due to the product error of the phase current sensor and the interleave control, so that the total value of the phase currents IL1 to IL4 does not necessarily change the true value of the input current to the FC-VCU 103. Since it is not always shown, it is also performed to complement this point.

  Note that the control cycle of the current sensor 105 and the control cycle of the phase current sensors 1051 to 1054 are different from each other in order to prevent control interference in the ECU 113. In the present embodiment, the control cycle of the current sensor 105 is earlier than the control cycle of the phase current sensors 1051 to 1054. This is, as described above, a change in the number of operating phases using the detected value, that is, a current sensor 105 that greatly affects the efficiency of the FC-VCU 103, and a current value of each phase driven using the detected value. This is due to the difference in the role of the auxiliary phase current sensors 1051 to 1054 in achieving the balance.

FIG. 35 is a flowchart illustrating an operation performed by the ECU 113 of the eighth control example according to the states of the current sensor 105 and the phase current sensors 1051 to 1054. As shown in FIG. 35, the ECU 113 performs a failure determination on the current sensor 105 and the phase current sensors 1051 to 1054 (step S801). Next, as a result of the failure determination performed in step S801, the ECU 113 determines whether the current sensor 105 is normal or abnormal (step S803). If the current sensor 105 is normal, the process proceeds to step S805. If so, the process proceeds to step S817. In step S805, the ECU 113 determines whether the phase current sensors 1051 to 1054 are normal or has a faulty abnormal state. If all of the phase current sensors 1051 to 1054 are normal, the process proceeds to step S807, If at least one of the sensors 1051 to 1054 has failed and is in an abnormal state, the process proceeds to step S811.

In step S807, the ECU 113 determines the number of operating phases of the FC-VCU 103 based on the input current IFC using, for example , the switching control of the number of operating phases described in the third control example . Next, the ECU 113 performs the phase current balance control based on the values of the phase currents IL1 to IL4 (step S809). In step S811, the ECU 113 executes power save control. Next, the ECU 113 determines the number of operating phases of the FC-VCU 103 based on the input current IFC (step S813). Further, the ECU 113 stops the phase current balance control (step S815). According to the above description, before stopping the phase current balance control (step S815), the ECU 113 executes the power save control (step S811). This is because the number of operating phases is reduced based on the value of the input current IFC limited by the power save, and even if the phase current balance control is stopped, deviation of the phase current of each phase hardly occurs.

  In step S817, the ECU 113 determines whether the phase current sensors 1051 to 1054 are normal or has a faulty abnormal state. If all of the phase current sensors 1051 to 1054 are normal, the process proceeds to step S819, and the phase current If at least one of the sensors 1051 to 1054 has failed and is in an abnormal state, the process proceeds to step S825. In step S819, the ECU 113 executes power save control. Next, the ECU 113 determines the number of operating phases of the FC-VCU 103 based on the sum of the phase currents IL1 to IL4 (step S821). Next, the ECU 113 performs the phase current balance control based on the values of the phase currents IL1 to IL4 (step S823). In step S825, the ECU 113 stops the control of the FC-VCU 103.

As described above, according to the eighth control example , even if at least one of the phase current sensors 1051 to 1054 or the current sensor 105 fails, the number of operating phases is switched so that the load is not concentrated on some of the phases. These controls can be continued by complementarily using the detected values of the normal current sensor for performing the control and the phase current balance control. As a result, even if some of the current sensors fail, it is possible to maintain the effects of the above control such as equalizing the load of each phase and suppressing concentration of the load on one phase.

(Ninth control example )
The ECU 113 of the ninth control example controls on / off switching of a switching element of the FC-VCU 103 output from the feedback loop outside a feedback control loop (hereinafter referred to as “feedback loop”) in the ECU 113 that controls the FC-VCU 103. An AC signal is superimposed on a control signal (hereinafter, simply referred to as a “control signal”). Further, the ECU 113 generates a pulse-like switching signal based on the control signal on which the AC signal is superimposed, and outputs the switching signal to each switching element of the FC-VCU 103. The AC component included in the switching signal is superimposed to measure the impedance of the fuel cell 101. Further, the amplitude value of the AC signal is set based on a tenth control example or an eleventh control example described later.

FIG. 36 is a block diagram illustrating a schematic configuration of an electric vehicle equipped with a power supply device having the ECU 113 of the ninth control example . As shown in FIG. 36, the ECU 113 of the ninth control example includes a feedback control unit 121, an AC signal generation unit 123, and a switching signal generation unit 125. In this control example , since the FC-VCU 103 is controlled in the current control mode, the ECU 113 receives the target value of the input current IFC of the FC-VCU 103 (hereinafter, referred to as “IFC current target value”) as an input, and the feedback control unit 121. Is formed, that is, a feedback loop is formed to feed back the detection value of the current sensor 105 (input current IFC).

  Feedback control section 121 outputs a control signal based on the difference between the IFC current target value and the value of input current IFC detected by current sensor 105. The AC signal generation unit 123 generates an AC signal to be superimposed on the control signal to measure the impedance of the fuel cell 101. The AC signal generated by the AC signal generator 123 is superimposed on the control signal output by the feedback controller 121 outside the feedback loop. The switching signal generation unit 125 generates a pulse-like switching signal based on the control signal on which the AC signal is superimposed, and outputs the switching signal to each switching element of the FC-VCU 103.

  Note that the control cycle in the above-described feedback loop is different from the control cycle in the stage where the AC signal is superimposed on the control signal outside the feedback loop, and the AC signal is superimposed as compared with the control cycle in the feedback loop. The control cycle at the stage is slower. This is because a relatively fast control cycle is required in the feedback loop so that the FC-VCU 103 can output a target voltage in a current control mode described later and a target current in a current control mode described later. On the other hand, it is preferable that the control cycle at the stage where the AC signal is superimposed be relatively slow so that there is no need for a fast control cycle so far and the impedance of the fuel cell 101 can be measured accurately.

  In the above description, the ECU 113 controls the FC-VCU 103 in the voltage control mode in which the voltage V2 is driven to be the optimum voltage at which the driving efficiency of the motor generator 11 is equal to or higher than the threshold value. Inputs the V2 voltage target value and feeds back the voltage V2. The ECU 113 may control the FC-VCU 103 in a current control mode in which the control of the FC-VCU 103 is stable. In this case, the target value of the output current of the FC-VCU 103 is input to the feedback loop, and the detected value of the output current is fed back. Also in this case, the AC signal generated by the AC signal generator 123 is superimposed on the control signal output by the feedback controller 121 outside the feedback loop.

  The ECU 113 changes the impedance of the fuel cell 101 by an AC impedance method based on the input current IFC of the FC-VCU 103 that is on / off controlled in accordance with the switching signal including the AC component and the output voltage of the fuel cell 101 that is also the input voltage V1. It measures and indirectly grasps the water-containing state inside the fuel cell 101. According to the AC impedance method, the ECU 113 samples each detection value of the current sensor 105 and the voltage sensor 1071 at a predetermined sampling rate, performs Fourier transform processing (FFT calculation processing or DFT calculation processing), and the like. The impedance of the fuel cell 101 is obtained by, for example, dividing the voltage value after the Fourier transform process by the current value after the Fourier transform process. The water-containing state inside the fuel cell 101 affects the ion conduction in the electrolyte inside the fuel cell 101, and therefore has a correlation with the impedance of the fuel cell 101. Therefore, by measuring the impedance of the fuel cell 101 by the AC impedance method described above, the water content inside the fuel cell 101 can be indirectly grasped.

As described above, according to the ninth control example , the timing at which the AC component included in the switching signal for controlling the switching element of the FC-VCU 103 to be turned on and off is superposed outside the feedback loop in the ECU 113. If the AC signal is superimposed in the feedback loop, especially when the AC signal has a high frequency, the fluctuation of the input current IFC of the FC-VCU 103, which is a feedback component, increases. And the control stability of the FC-VCU 103 may be reduced.

  In addition, in principle, unless the control cycle in the feedback loop is made sufficiently earlier than the AC signal to be superimposed, the AC signal cannot be recognized by the ECU 113, so that the AC superposition cannot be performed. Therefore, especially when the AC signal has a high frequency, the control cycle in the feedback loop becomes very fast, and the calculation load on the ECU 113 becomes enormous.

However, since the control cycle outside the feedback loop is slower than the control cycle in the feedback loop, by superimposing an AC signal outside the feedback as in this control example , the above-described problem does not occur, and the FC-VCU 103 It is possible to measure the impedance of the fuel cell 101 while ensuring the control stability of the above and suppressing the calculation load of the ECU 113. By adjusting the humidification amount of the fuel gas supplied to the fuel cell 101 based on the measured impedance of the fuel cell 101, the water-containing state of the fuel cell 101 can be always maintained in an appropriate state, Deterioration and efficiency reduction can be suppressed.

Although the input current IFC is fed back in the feedback loop in the ECU 113 of the present control example , a feedback loop in which the output voltage V2 of the FC-VCU 103 feeds back may be used.

(Tenth control example )
When the FC-VCU 103 is driven in a single phase, only one of the plurality of switching elements included in the FC-VCU 103 is on / off switched. Therefore, even if the AC component is superimposed on the switching signal for controlling the switching element, if the amplitude of the AC component is appropriate, the zero crossing in the phase current is suppressed, and the control stability of the FC-VCU 103 is impaired. Absent. However, when the FC-VCU 103 is driven in multiple phases, since a plurality of switching elements are controlled to be turned on and off, an AC component superimposed on each switching signal causes a zero-cross of any phase current or a switching to a switching element. On the other hand, the control stability of the FC-VCU 103 may be reduced due to the AC superposition control performed in addition to the normal duty control and the interleave control. This possibility increases when performing interleave control for shifting the on / off switching phase of the switching element. The AC component included in the switching signal to the FC-VCU 103 is superimposed for measuring the impedance of the fuel cell 101 described in the ninth control example .

In view of the above circumstances, the ECU 113 of the tenth control example sets a section corresponding to the number of operating phases of the FC-VCU 103 determined based on the input current IFC to the FC-VCU 103. Then, the ECU 113 superimposes an AC signal having an amplitude value suitable for each section on a control signal (hereinafter, simply referred to as a “control signal”) for controlling on / off switching of the switching element of each drive phase. The ECU 113 generates a pulse-like switching signal based on the control signal on which the AC signal is superimposed as described above, and outputs the switching signal to the FC-VCU 103. Further, the section corresponding to the case where the FC-VCU 103 is driven in one phase is divided into two sections, and the ECU 113 superimposes an AC signal having an amplitude value suitable for each section on the drive phase control signal. Outputs a switching signal.

FIG. 37 is a diagram of a tenth control example showing the basic amplitude of the AC signal and the change over time of the basic amplitude total value according to the number of operating phases of the FC-VCU 103. FIG. 38 is a diagram for explaining the difference in the waveform of the input current IFC due to the magnitude of the amplitude of the AC signal superimposed when driving the FC-VCU 103 in one phase, where the value of the input current IFC is close to 0 (A). FIG. On the left side of FIG. 38, two AC signals having the same period but different amplitudes are shown. The amplitude of the AC signal on the upper left of FIG. 38 is smaller than the amplitude of the AC signal on the lower left of FIG. On the right side of FIG. 38, a waveform of the input current IFC including an AC component corresponding to the AC signal shown on the left side of FIG. 38 is shown. Note that the DC component of the input current IFC is based on the magnitude of the control signal.

If the amplitude of the AC signal to be superimposed is small, a sufficient AC component does not appear in each detection value of the current sensor 105 and the voltage sensor 1071, and the impedance of the fuel cell 101 cannot be measured accurately. Therefore, it is preferable that the amplitude of the AC signal to be superimposed is large enough not to affect the performance of the fuel cell 101 or to impair the control stability of the fuel cell 101 or the FC-VCU 103. However, the input current IFC when the FC-VCU 103 is driven in one phase is smaller than that in the case where the FC-VCU 103 is driven in multiple phases. When the signal is superimposed, the amplitude of the input current IFC appearing for the AC signal increases, and as shown in the lower right of FIG. 38, the input current IFC is discontinuous including a period in which the value becomes 0 (zero-crossing). It becomes a waveform. Such a discontinuous waveform of the input current IFC is not preferable because it makes the control of the fuel cell 101 unstable. Therefore, in the present control example , as shown in FIG. 37, when the FC-VCU 103 is driven in one phase, it is divided into two sections, section 1 and section 2, according to the magnitude of the input current IFC. In the section 1 in which the input current IFC is small, the ECU 113 changes the basic amplitude of the AC signal per drive phase (hereinafter referred to as “basic superposition amount”) into a discontinuous waveform as the input current IFC increases. Raise gradually so that it does not become. Then, the section 2 is set to be equal to or more than the input current IFC at which the basic overlap amount reaches the threshold value thac. In the section 2, since the threshold value thac suitable as the basic superimposition amount can be superimposed without making the input current IFC discontinuous, the ECU 113 sets the basic superimposition amount to the threshold value thac regardless of the magnitude of the input current IFC. Set to.

  In the section 3 corresponding to the case where the FC-VCU 103 is driven in two phases, the ECU 113 determines that the sum of the amplitudes of the AC signals superimposed on the control signals of the two drive phases is not suitable as the above-described basic superimposition amount. The basic superimposition amount is set to “thac / 2” regardless of the magnitude of the input current IFC so as to be equal to the threshold value thac. Similarly, in section 4 corresponding to the case where FC-VCU 103 is driven in four phases, ECU 113 determines that the sum of the amplitudes of the AC signals superimposed on the control signals of the four drive phases is a suitable threshold as the basic superimposed amount. The basic superimposition amount is set to “thac / 4” so as to be equal to the value thac, regardless of the magnitude of the input current IFC. Note that the ECU 113 may set the basic superimposition amount in a section when the FC-VCU 103 is driven in multiple phases (n phases) to a value that is reduced from “thac / n” as the input current IFC increases.

  Further, the ECU 113 multiplies the basic superimposition amount by a different coefficient according to the boost rate of the FC-VCU 103. FIG. 39 is a diagram illustrating a relationship between the boost rate of the FC-VCU 103 and a coefficient by which the basic superimposition amount is multiplied. As shown in FIG. 39, the coefficient by which the basic superimposition amount is multiplied is smaller as the boosting ratio is larger. This is because the higher the boosting ratio, the greater the ripple of the input current IFC, and thus the easier the AC superposition. The ECU 113 multiplies a coefficient corresponding to the boost rate of the FC-VCU 103 by a basic superimposition amount derived based on the relationship in FIG. 37, and then converts an AC signal having an amplitude value indicated by the calculated value into a control signal of each drive phase. A switching signal obtained by superimposition is output.

As described above, according to the tenth control example , since the amplitude of the AC component included in the switching signal is a value suitable for each section, the control stability of the FC-VCU 103 is not impaired by the AC component. In addition, the impedance of the fuel cell 101 can be accurately measured.

  The example shown in FIG. 37 shows a case where the number of operating phases of the magnetic coupling type FC-VCU 103 shown in FIGS. 2 and 6 is one, two, or four. When using the FC-VCU 203 in which the iron core of the reactor of each phase shown is independent, the number of operating phases of one to four phases including three phases is used. In this case, in the section corresponding to the case where the FC-VCU 103 is driven in three phases, the ECU 113 determines that the sum of the amplitudes of the AC signals superimposed on the control signals of the three drive phases is not suitable as the above-described basic superimposition amount. The basic superimposition amount is set to “thac / 3” so as to be equal to the threshold value thac regardless of the magnitude of the input current IFC.

(Eleventh control example )
When the FC-VCU 103 is driven in a single phase, only one of the plurality of switching elements included in the FC-VCU 103 is on / off switched. Therefore, even if the AC component is superimposed on the switching signal for controlling the switching element, if the amplitude of the AC component is appropriate, the zero crossing in the phase current is suppressed, and the control stability of the FC-VCU 103 is impaired. Absent. However, when the FC-VCU 103 is driven in multiple phases, since a plurality of switching elements are controlled to be turned on and off, an AC component superimposed on each switching signal causes a zero-cross of any phase current or a switching to a switching element. On the other hand, the control stability of the FC-VCU 103 may be reduced due to the AC superposition control performed in addition to the normal duty control and the interleave control. In addition, as the number of operating phases when the FC-VCU 103 is driven in multiple phases increases, the control stability due to the AC component included in each switching signal becomes more remarkable. The AC component included in the switching signal to the FC-VCU 103 is superimposed for measuring the impedance of the fuel cell 101 described in the ninth control example .

In view of the above circumstances, the ECU 113 of the eleventh control example sets a section corresponding to the number of operating phases of the FC-VCU 103 determined based on the input current IFC to the FC-VCU 103. Then, the ECU 113 superimposes an AC signal having an amplitude value suitable for each section on a control signal (hereinafter, simply referred to as a “control signal”) for controlling on / off switching of the switching element of each drive phase. The ECU 113 generates a pulse-like switching signal based on the control signal on which the AC signal is superimposed as described above, and outputs the switching signal to the FC-VCU 103. Further, the section corresponding to the case where the FC-VCU 103 is driven in one phase is divided into two sections, and the ECU 113 superimposes an AC signal having an amplitude value suitable for each section on the drive phase control signal. Outputs a switching signal.

FIG. 40 is a diagram of an eleventh control example showing a basic amplitude of an AC signal according to the number of operating phases of the FC-VCU 103 and a temporal change of the basic amplitude total value. FIG. 41 is a diagram illustrating an input current IFC near 0 (A) for explaining a difference in waveform of the input current IFC due to the magnitude of the amplitude of the AC signal superimposed when the FC-VCU 103 is driven in one phase. FIG. On the left side of FIG. 41, two AC signals having the same period and different amplitudes are shown. The amplitude of the AC signal on the upper left of FIG. 41 is smaller than the amplitude of the AC signal on the lower left of FIG. 41. On the right side of FIG. 41, a waveform of the input current IFC including an AC component corresponding to the AC signal shown on the left side of FIG. 41 is shown. Note that the DC component of the input current IFC is based on the magnitude of the control signal.

If the amplitude of the AC signal to be superimposed is small, a sufficient AC component does not appear in each detection value of the current sensor 105 and the voltage sensor 1071, and the impedance of the fuel cell 101 cannot be measured accurately. Therefore, it is preferable that the amplitude of the AC signal to be superimposed is large enough not to affect the performance of the fuel cell 101 or to impair the control stability of the fuel cell 101 or the FC-VCU 103. However, the input current IFC when the FC-VCU 103 is driven in one phase is smaller than that in the case where the FC-VCU 103 is driven in multiple phases. When the signal is superimposed, the amplitude of the input current IFC that appears due to the AC component increases, and as shown in the lower right of FIG. 41, the input current IFC is discontinuous including a period in which the value is 0 (zero-crossing). It becomes a waveform. Such a discontinuous waveform of the input current IFC is not preferable because it makes the control of the fuel cell 101 unstable. Therefore, in the present control example , as shown in FIG. 40, when the FC-VCU 103 is driven in one phase, it is divided into two sections, section 1 and section 2, according to the magnitude of the input current IFC. In the section 1 in which the input current IFC is small, the ECU 113 changes the basic amplitude of the AC signal per drive phase (hereinafter referred to as “basic superposition amount”) into a discontinuous waveform as the input current IFC increases. Raise gradually so that it does not become. Then, the section 2 is set to be equal to or more than the input current IFC at which the basic overlap amount reaches the threshold value thac. In the section 2, since the threshold value thac suitable as the basic superimposition amount can be superimposed without making the input current IFC discontinuous, the ECU 113 sets the basic superimposition amount to the threshold value thac regardless of the magnitude of the input current IFC. Set to.

In the section 3 corresponding to the case where the FC-VCU 103 is driven in two phases, the ECU 113 determines that the sum of the amplitudes of the AC signals superimposed on the control signals of the two drive phases is not suitable as the above-described basic superimposition amount. The basic superimposition amount is set to “thac / 2” regardless of the magnitude of the input current IFC so as to be equal to the threshold value thac. Note that the ECU 113 may set the basic superimposition amount to a value reduced from “thac / 2” as the input current IFC increases. This is because, as the input current IFC increases, the ripple of the input current IFC increases, which facilitates AC superposition. In the section 4 corresponding to the case where the FC-VCU 103 is driven in four phases, the ECU 113 sets the basic superimposition amount to 0 regardless of the magnitude of the input current IFC. That is, the ECU 113 prohibits the superposition of the AC signal when the FC-VCU 103 is driven in four phases. In the present control example , for the same reason as in the fourth control example , as the number of operating phases of the FC-VCU 103, odd phases other than one phase are prohibited. Therefore, when the FC-VCU 103 is driven in three phases, no AC signal is superimposed.

  Further, the ECU 113 multiplies the basic superimposition amount by a different coefficient according to the boost rate of the FC-VCU 103. FIG. 42 is a diagram illustrating a relationship between the boost rate of the FC-VCU 103 and a coefficient by which the basic superimposition amount is multiplied. As shown in FIG. 42, the coefficient by which the basic superimposition amount is multiplied decreases as the boosting rate increases. This is because, as described above, as the boosting ratio increases, the ripple of the input current IFC increases, which facilitates AC superposition. The ECU 113 multiplies the coefficient corresponding to the boost rate of the FC-VCU 103 by the basic superposition amount derived based on the relationship in FIG. 40, and then converts the AC signal of the amplitude value indicated by the calculated value into the control signal of each drive phase. A switching signal obtained by superimposition is output.

FIG. 43 is a flowchart illustrating an operation performed by the ECU 113 of the eleventh control example when an AC signal is superimposed on a control signal of a drive phase. As shown in FIG. 43, the ECU 113 derives a basic superimposition amount in a section corresponding to the input current IFC to the FC-VCU 103 (step S1101). Next, the ECU 113 derives a coefficient corresponding to the boost rate of the FC-VCU 103 (step S1103). Next, the ECU 113 outputs a switching signal obtained by superimposing an AC signal having an amplitude value obtained by multiplying the basic superimposition amount by a coefficient on the control signal of each drive phase (step S1105). Next, the ECU 113 measures the impedance of the fuel cell 101 by the AC impedance method described in the ninth control example (step S1107). Next, the ECU 113 determines the water-containing state of the fuel cell 101 according to the impedance of the fuel cell 101 (step S1109). Next, the ECU 113 humidifies the fuel cell 101 in an amount corresponding to the water content determined in step S1109 (step S1111).

As described above, according to the eleventh control example , since the amplitude of the AC component included in the switching signal is a value suitable for each section, the control stability of the FC-VCU 103 is not impaired by the AC component. , The impedance of the fuel cell 101 can be measured.

Note that the present invention is not limited to the above-described embodiment, and can be appropriately modified and improved. For example, the above-described first to eleventh control examples are described independently of each other, but a power supply device combining two or more control examples may be used. Further, the above-described electric vehicle includes the fuel cell 101 and the battery 17 as energy sources. Instead of the fuel cell 101, a secondary battery such as a lithium ion battery or a nickel hydrogen battery having a higher energy weight density than the battery 17 is used. May be used. In this case, as shown in FIG. 44, each conversion unit of the FC-VCU 103 is provided with a switching element in parallel with a diode connected in series to the reactor, and the ECU 113 uses two switching elements including a high side and a low side. By performing the on / off switching operation, the voltage of the secondary battery provided in place of the fuel cell 101 is boosted and output.

  Further, the above-described electric vehicle is a 1MOT-type EV (Electrical Vehicle). However, even if the EV includes a plurality of motor generators, the HEV (Hybrid Electrical Vehicle) includes an internal combustion engine together with at least one motor generator. ) Or PHEV (Plug-in Hybrid Electrical Vehicle). Further, in the present embodiment, the power supply device 100 is mounted on the electric vehicle, but the power supply device 100 may be provided in an electric device not intended for transportation. The power supply device 100 is suitable for a power supply capable of outputting a large current, and it is particularly preferable to apply the power supply device 100 to a computer in which the increase in current is remarkable in recent years.

  The VCU 15 of the present embodiment boosts the voltage of the battery 17, but when the voltage of the fuel cell 101 is lower than the voltage of the battery 17, a VCU that reduces the voltage of the battery 17 is used. Further, a VCU capable of stepping up and down in both directions may be used. Further, the FC-VCU 103 is not limited to the step-up type, and may be a step-down type or a step-up / step-down type.

11 Motor generator (MG)
13 PDU
15 VCU
17 Battery 100 Power supply device 101 Fuel cell (FC)
103, 203 FC-VCU
105 Current sensor 1051 to 1054 Phase current sensor 1071, 1072 Voltage sensor 1091 to 1094 Temperature sensor 111 Power switch 113 ECU
121 Feedback control unit 123 AC signal generation unit 125 Switching signal generation unit C1, C2 Smoothing capacitors L1 to L4 Reactors Coa, Cob Iron core

Claims (10)

Power and
A conversion module having a plurality of conversion units capable of voltage conversion of the power supplied by the power supply, and the plurality of conversion units are electrically connected in parallel,
A first current sensor for detecting a current flowing between the power supply and the conversion module;
A second current sensor for detecting a current flowing through each of the plurality of converters;
Using a detection value of the first current sensor or a detection value of the second current sensor, a first control unit that performs first control that changes the number of operations that is the number of the conversion units that perform the voltage conversion,
When the number of operations is plural, a second control unit that performs second control to equalize currents flowing through the conversion units of the number of operations using a detection value of the second current sensor;
Depending on whether the first current sensor and the second current sensor are normal or abnormal, a detection value used in performing the first control is a detection value of the first current sensor and the second current sensor. And a determining unit that determines whether or not to perform the second control.
A power supply device comprising: The power supply device according to claim 1,
If the first current sensor and the second current sensor are normal, the determination unit determines a detection value used when performing the first control as a detection value of the first current sensor, and Power supply that decides to do. The power supply device according to claim 1 or 2,
The power supply device, wherein the determining unit determines that the second control is to be performed using a detection value of the second current sensor when at least the second current sensor is normal. The power supply device according to any one of claims 1 to 3, wherein
If the first current sensor is normal and the second current sensor is abnormal, the determination unit determines a detection value used when performing the first control as a detection value of the first current sensor, A power supply unit that determines not to perform the second control. The power supply device according to claim 1, wherein:
If the first current sensor is abnormal and the second current sensor is normal, the determination unit determines a detection value used when performing the first control as a detection value of the second current sensor, Determining to perform the second control,
The power supply device, wherein the first control unit performs the first control using a total value of detection values of the second current sensor. The power supply device according to any one of claims 1 to 5, wherein
A control unit that drives the conversion unit that performs the voltage conversion and controls the conversion module,
The power supply device, wherein the control unit performs control to reduce an input current from the power supply to the conversion module when the first current sensor or the second current sensor is abnormal. The power supply device according to any one of claims 1 to 6, wherein
A power supply device, wherein a control cycle of the first control using a detection value of the first current sensor and a control cycle of the second control are different from each other. The power supply device according to claim 7, wherein
The power supply device, wherein a control cycle of the first control using a detection value of the first current sensor is earlier than a control cycle of the second control.   An apparatus comprising the power supply device according to claim 1. Power and
A conversion module having a plurality of conversion units capable of voltage conversion of the power supplied by the power supply, and the plurality of conversion units are electrically connected in parallel,
A first current sensor for detecting a current flowing between the power supply and the conversion module;
A second current sensor for detecting a current flowing through each of the plurality of converters;
Using a detection value of the first current sensor or a detection value of the second current sensor, a first control unit that performs first control that changes the number of operations that is the number of the conversion units that perform the voltage conversion,
When the number of operations is plural, a power supply device including: a second control unit that performs a second control to equalize currents flowing through the conversion units of the number of operations using a detection value of the second current sensor. Control method to be performed,
Depending on whether the first current sensor and the second current sensor are normal or abnormal, a detection value used in performing the first control is a detection value of the first current sensor and the second current sensor. And determining whether or not to perform the second control.

Images