JP2003203663A - Fuel cell power generating system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel cell power generating system with a new structure which prevents a rush current usually generated at the start of the system. <P>SOLUTION: The fuel cell power generating system comprises a fuel cell 16 generating electricity by the electrochemical reaction of fuel gas 12 and oxidant gas 14, a DC/DC converter 18 transforming the direct current voltage outputted from the fuel cell 16 into a prescribed direct current voltage, and a capacitor 20 connected to the output side of the DC/DC converter 18. By constructing like above, the DC/DC converter 18 can have a control part 22 controlling the DC/DC converter 18 main body, and the control part 22 can make the output voltage of the DC/DC converter 18 increase from zero to a prescribed voltage with a prescribed gradient when starting the DC/DC converter 18. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a fuel cell power generation system for converting the output of a fuel cell from direct current to alternating current,
In particular, the present invention relates to a fuel cell power generation system that suppresses an inrush current generated when the fuel cell power generation system is activated.

[0002]

2. Description of the Related Art A conventional fuel cell power generation system for obtaining electric power from a polymer electrolyte fuel cell includes a reformer 10, a fuel cell 16, a DC / DC converter 18, as shown in FIG.
A DC / AC inverter 40, an input current detection circuit 32, a driver circuit 30, an output voltage detection circuit 38, and a switching control circuit 34 are provided, and a DC voltage output from the fuel cell 16 is converted into a predetermined DC voltage by a DC / DC converter 18. After boosting to a voltage, a commercial power source with an AC fixed frequency was generated through the DC / AC inverter 40.

The fuel cell 16 is supplied with hydrogen-rich gas as the fuel gas 12 from the reformer 10, and the oxidant gas 1
Oxygen or air as 4 is supplied to generate direct current electricity. This direct current electricity is converted from low voltage direct current electricity to high voltage direct current electricity by the DC / DC converter 18, and is further converted from direct current electricity to alternating current electricity by the DC / AC inverter 40 to obtain 100 V / 50 Hz or 200 V / 50.
It was generating electric power as a commercial power source with an AC fixed frequency such as Hz.

A control unit 22 including a switching control circuit
Is the DC as the start signal 112 as shown in FIG.
Driver circuit 30 in response to the start of the DC / DC converter
Is operated to supply high-voltage DC electricity to the DC / AC inverter 40 via the step-up transformer 24.
/ DC converter 18 and DC / AC inverter 40 smoothing capacitor 20 as a capacitor is connected to DC / AC during several milliseconds inrush current 110 of several 10A to 100A as shown in FIG. Inverter 40
However, there is a problem in that the cells inside the fuel cell 16 are damaged or deteriorated, and the electronic components forming the DC / DC converter 18 and the DC / AC inverter 40 are damaged.

For the purpose of mitigating the inrush current 110, conventionally, a DC / AC inverter 102 with an inrush current prevention circuit as shown in FIG. 10 has been used. This inrush current prevention circuit, when inputting the start signal 112,
Current is supplied to the smoothing capacitor 7 of the DC / AC inverter through the resistor 11 having a large current capacity, and after the fuel cell power generation system shifts to a normal operating state, the switching control unit 100 clamps both terminals of the resistor 11. The switch 104 was closed and DC electricity was supplied from the DC / DC converter 18.

[0006]

However, in such a conventional fuel cell power generation system, the DC / AC inverter 1 is used.
As the current capacity of 02 increases, it is necessary to select a resistor having a value proportional to the square of the inrush current 110 as the current capacity of the resistor 11 for preventing the inrush current, and during operation of the fuel cell power generation system. In order to provide the switch 104 and the opening / closing control unit 100 for preventing the resistor 11 from being heated or damaged,
The fuel cell power generation system has been increased in size and the manufacturing cost has been increased.

Therefore, an object of the present invention is to provide a fuel cell power generation system having a new mechanism for preventing an inrush current generated at the time of starting the fuel cell power generation system.

[0008]

In order to achieve the above object, a fuel cell power generation system according to a first aspect of the present invention is provided with a fuel gas 12 and an oxidant gas 14 as shown in FIG.
The fuel cell 16 is connected to the output side of the DC / DC converter 18, which transforms the DC voltage output from the fuel cell 16 into a predetermined DC voltage, and the DC / DC converter 18 which generates electric power by an electrochemical reaction with the DC / DC converter 18. And a capacitor 20. The DC / DC converter 18 includes a control unit 22 that controls the main body of the DC / DC converter 18, and the control unit 22
Is configured to increase the output voltage with a predetermined gradient to boost the output voltage from zero to a predetermined DC voltage when the DC / DC converter 18 is started.

With this configuration, the output voltage detection circuit 38 detects the DC voltage applied to the capacitor 20 through the intermediate node voltage of the dividing resistor 27 and feeds it back to the switching control circuit 34. The switching control circuit 34 controls the conduction period of the switching element 28 while comparing the fed back DC voltage with the startup control voltage that increases with time, and controls the DC voltage applied to the capacitor 20 from zero to a predetermined DC voltage. It can be increased with a certain slope to prevent inrush current. Therefore, it is possible to prevent performance deterioration of the fuel cell power generation system and local deterioration of the material.

In order to achieve the above object, a fuel cell power generation system according to a second aspect of the present invention uses an electrochemical reaction between a fuel gas 12 and a fuel gas as an oxidant gas 12, as shown in FIG. A fuel cell 16 for generating power, a DC / DC converter 18 for converting a DC voltage output from the fuel cell 16 into a predetermined DC voltage, and a capacitor 20 connected to an output side of the DC / DC converter 18 are provided. The DC / DC converter 18 has a control unit 22 that controls the main body of the DC / DC converter 18, and the control unit 22 boosts the output voltage from zero to a predetermined DC voltage when the DC / DC converter 18 is started. The input current of the DC / DC converter 18 is limited.

With such a configuration, the input current maximum value control circuit 46 that has received the start signal commands the switching control circuit 34 to start activation of the maximum input current value of the fuel cell power generation system, and the switching control circuit 34 causes the driver circuit to operate. The conduction period of the switching element 28 is controlled through 30. The switching control circuit 34 monitors the input current of the DC / DC converter 18 through the input current detection circuit 32, and monitors the output voltage of the DC / DC converter 18 through the output voltage detection circuit 38.

Further, the switching control circuit 34 uses a DC
The start-up period can be determined based on the output voltage of the / DC converter 18, and the conduction period of the switching element 28 can be controlled so that the input current of the monitored DC / DC converter 18 does not exceed a predetermined maximum value.

Subsequently, the switching control circuit 34
When the output voltage of the monitored DC / DC converter 18 is boosted to the charging voltage of the capacitor 20, the conduction period of the switching element 28 is changed to the operation mode, and the maximum limit of the input current is released.

The switching control circuit 34 can limit the input current of the DC / DC converter 18 in order to boost the DC voltage applied to the capacitor 20 from zero to a predetermined DC voltage, and prevent inrush current. Therefore, it is possible to prevent performance deterioration of the fuel cell power generation system and local deterioration of the material.

To achieve the above object, a fuel cell power generation system according to a third aspect of the present invention converts a DC voltage output from a DC / DC converter 18 into an AC voltage, as shown in FIGS. 1 and 4. DC / AC inverter 4
0, the capacitor 20 is a DC / AC inverter 40
Form part of.

With this configuration, it is possible to generate stable AC electricity during operation while preventing inrush current that occurs at the time of starting the fuel cell power generation system, and to reduce the performance of the fuel cell power generation system and local materials. It is possible to prevent deterioration.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. In each drawing, the same or corresponding members are designated by the same reference numerals or similar reference numerals, and redundant description will be omitted.

FIG. 1 is a block diagram of a fuel cell power generation system according to a first embodiment of the present invention. The fuel cell power generation system includes a fuel cell 16, a DC / DC converter 18, a DC / AC inverter 40, and a control unit 22, and the fuel cell 16 includes a hydrogen rich gas 12 as a fuel gas and an oxidizer from a reformer 10. Oxygen or air as the gas 14 is supplied to generate direct current electricity by an electrochemical reaction,
It converts DC electricity into AC electricity and supplies electricity to the outside.

The control unit 22 is connected to the DC / DC converter 18, and includes a driver circuit 30, an input current detection circuit 32, an output voltage detection circuit 38, an output voltage gradient command circuit 36, and a switching control circuit 34. To have.

The DC / DC converter 18 includes an input current detector 23, a step-up transformer 24, a rectifying diode 25 as a rectifier, a current smoothing reactor 26, a dividing resistor 27, and a pair of switching elements 28. To do. It is a transformer that inputs low-voltage DC electricity and outputs high-voltage DC electricity.

The DC / AC inverter 40 has an inverter switching element group 42 which is connected to the smoothing capacitor 20 on the input side and receives gate control from a microcomputer as a control circuit, and which is complementary to the inverter switching element 42. A constant frequency AC voltage can be supplied to the AC output 44 by such a conducting action.
For example, a commercial power source such as 100V / 200V at 50/60 Hz can be supplied, and it can be connected to an existing commercial power source line to cope with an increase / decrease in load.

The electric power output from the fuel cell 16 is, for example, DC electricity of about 50 V which is supplied to the DC / DC converter 18. For example, the DC electricity positive voltage line is connected to the input intermediate tap of the step-up transformer 24. The direct current negative voltage line is connected to both terminals of the step-up transformer 24 via a switching element 28.

The switching control circuit 34 complementarily drives the switching element 28 via the driver circuit 30 so that when one switching element is ON, the other switching element is OFF. Due to the complementary conduction of the switching element 28, the step-up transformer 24 changes the direction of the current flowing inside the step-up transformer 24 with time, and outputs the current to the output side of the step-up transformer 24, for example, 10
It outputs AC electricity of about 300 V at a frequency of 100 kHz from 100 kHz.

A current smoothing reactor 26 is connected to the output terminal of the step-up transformer 24 via a rectifying diode 25 as a rectifier, and is connected to a positive voltage DC line. On the other hand, a negative voltage DC line is connected to the output center tap. To the positive and negative DC lines, for example, a dividing resistor 27 that outputs DC electricity of about 300 V and detects the potential level is connected. In the present embodiment, the push-pull method is used as the step-up method of the DC / DC converter 18, but a step-up chopper method as a means for stepping up DC electricity, or a voltage doubler rectifier composed of a smoothing capacitor and a switching element that does not use a transformer. A scheme can be used.

A start signal is input to the control unit 22 while the fuel cell 16 is outputting DC electricity. Upon receiving the start signal, the output voltage gradient command circuit 36 issues an output voltage gradient command to the switching control circuit 34 to start the start mode of the power generation system. The output voltage gradient parameter can be configured only by hardware, and is also written in the PROM or the ROM in the microcomputer to
It is stored as time-series data that rises from a voltage value to a predetermined voltage value.

The switching control circuit 34 receives the output voltage data of the DC / DC converter 18 through the output voltage detection circuit 38 and the DC through the input current detection circuit 32.
It is possible to receive the input current data of the / DC converter 18 and simultaneously monitor the input current and the output voltage. Analog values may be used for the monitored input current and output voltage. You may use the digitized value. For the input current detection circuit 32 and the output voltage detection circuit 38, an AD converter that converts an analog value of current or voltage into a digital signal can be used.

The switching control circuit 34 can control the complementary conducting operation of the switching element 28 to limit the voltage value to such a level that no transient inrush current is generated. For example, when the output voltage gradient command is issued in response to the start signal, both the input current and the output voltage of the DC / DC converter 18 are zero values.

The switching control circuit 34 complementarily drives the switching element 28 through the driver circuit 30 to control the input current of the DC / DC converter 18 to such an extent that it slightly increases from zero. DC as input current increases
Although the output voltage of the / DC converter 18 also increases, it can be controlled by the switching control circuit 34 so that the output voltage has a gradient.

FIG. 2 is a timing chart of the fuel cell power generation system according to the first embodiment of the present invention.
The switching control circuit 34 includes the DC / DC converter 1
The switching element 28 is driven complementarily while monitoring the output voltage of the switch 8. For example, in the input stage of the start signal, the conduction period of the switching element 28 can be controlled to be short, and the conduction period can be controlled to be gradually increased so as to gradually change.

As shown in the lower part of FIG. 2, the output voltage of the DC / DC converter 18 is zero volt at the time of starting the DC / DC converter, and is controlled so as to gradually increase with the passage of time. . The slope of the output voltage of the DC / DC converter 18 can be set to, for example, about 10 seconds for increasing the voltage from zero volt to the rated 300 volt.

As shown in the upper part of FIG. 2, the input current of the DC / AC inverter 40 is controlled to be zero ampere at the time of starting the DC / DC converter and gradually increase with the passage of time. There is. For example, when the gradient of the input current of the DC / AC inverter 40 rises from zero amps to about 10 amps, the smoothing capacitor 20 is fully charged, then returns to zero amps, and power is supplied at the rated operation. The smoothing capacitor 20 can be controlled to be repeatedly charged and discharged during the period.

FIG. 3 is a timing chart of the fuel cell power generation system according to the first embodiment of the present invention.
The switching control circuit 34 applies to the gate of the switching element 28 a signal that changes with time as shown in the figure. The output voltage of the DC / DC converter 18 at the time indicated by the start is zero volt.

The switching control circuit 34 can output a rectangular wave having a narrow pulse width at the start point and modulate the signal so as to widen the pulse width with the passage of time. For example, the illustrated waveform is applied to one gate of the switching element 28 and is a waveform in which the duty ratio of the signal is changed. A signal having a complementary relationship with the illustrated signal is applied to the other switching element 28.

FIG. 4 is a block diagram of a fuel cell power generation system according to a second embodiment of the present invention. The fuel cell power generation system includes a fuel cell 16, a DC / DC converter 18, a DC / AC inverter 40, and a control unit 22, and the fuel cell 16 includes a hydrogen rich gas 12 as a fuel gas and an oxidizer from a reformer 10. Oxygen or air as the gas 14 is supplied, DC electricity is generated by an electrochemical reaction, DC electricity is converted to AC electricity, and electricity is supplied to the outside.

The internal structures of the control unit 22, the DC / DC converter 18, the DC / AC inverter 40, and the switching control circuit 34 are the same as those in the first embodiment described above, and their explanations are omitted.

The switching control circuit 34 complementarily drives the switching element 28 through the driver circuit 30 to control the input current of the DC / DC converter 18 so as to rise from zero to a predetermined current value. The output voltage of the DC / DC converter 18 is gradually increased by the preset input current and can be controlled to have a predetermined slope from zero volt.

A start signal is input to the control unit 22 while the fuel cell 16 is outputting DC electricity. The input current maximum value control circuit 46 which has received the start signal issues an input current maximum value command to the switching control circuit 34 to start the start mode of the power generation system.

The switching control circuit 34 receives the output voltage data of the DC / DC converter 18 through the output voltage detection circuit 38 and the DC through the input current detection circuit 32.
It is possible to receive the input current data of the / DC converter 18 and simultaneously monitor the input current and the output voltage. Analog values may be used for the monitored input current and output voltage. You may use the digitized value. For the input current detection circuit 32 and the output voltage detection circuit 38, an AD converter that converts an analog value of current or voltage into a digital signal can be used.

As shown in the lower part of FIG. 5, the output voltage of the DC / DC converter 18 is zero volt at the time of starting the DC / DC converter, and is controlled so as to gradually increase with the passage of time. The slope of the output voltage of the DC / DC converter 18 can be set to, for example, about 10 seconds for increasing the voltage from zero volt to the rated 300 volt.

As shown in the upper part of FIG. 5, the input current of the DC / AC inverter 40 is controlled to be zero ampere at the time of starting the DC / DC converter and gradually increase with the passage of time. There is. For example, when the gradient of the input current of the DC / AC inverter 40 rises from zero amps to about 10 amps, the smoothing capacitor 20 is fully charged, then returns to zero amps, and power is supplied at the rated operation. The smoothing capacitor 20 can be controlled to be repeatedly charged and discharged during the period.

As shown in the middle part of FIG. 5, the input current of the DC / DC converter 18 rises to a predetermined set current from the time when the DC / DC converter is started and does not change with time, and the smoothing capacitor 20 is fully charged. The current returns to zero amperage at the stage of charging, and then the current is increased / decreased by ON / OFF control of the switching element 28 so that charging / discharging of the smoothing capacitor 20 is repeated during the period of supplying the electric power in the rated operation.

FIG. 6 is a timing chart of the fuel cell power generation system according to the second embodiment of the present invention.
The switching control circuit 34 applies a periodic pulse signal as shown to the gate of the switching element 28. DC / DC converter 18 at the time indicated by the start
Although its output voltage is zero volt, it can be controlled to increase with a predetermined gradient by this periodic switching control.

Although the present embodiment has been described as applying the pulse shown in FIG. 6 to the gate of the switching element 28, as another means for limiting the input current of the DC / DC converter 18. A wide variety of switching elements 28 such as depletion type MOSFETs and IGBTs can be used to limit the input current.

FIG. 7 is a block diagram of a fuel cell power generation system according to a third embodiment of the present invention. The fuel cell power generation system includes a fuel cell 16, a DC / DC converter 18, a DC / AC inverter 40, and a control unit 22, and the fuel cell 16 includes a hydrogen rich gas 12 as a fuel gas and an oxidizer from a reformer 10. Oxygen or air as the gas 14 is supplied, direct current electricity is generated by an electrochemical reaction, direct current electricity is converted into alternating current electricity, and electric power is supplied to the outside.

The internal structures of the control unit 22, the DC / DC converter 18, the DC / AC inverter 40, and the switching control circuit 34 are the same as those in the first and second embodiments described above, and their explanations are omitted.

The switching control circuit 34 complementarily drives the switching element 28 through the driver circuit 30 to control the input current of the DC / DC converter 18 to increase from zero to a predetermined current value. The output voltage of the DC / DC converter 18 is gradually increased by the preset input current and can be controlled to have a predetermined slope from zero volt.

When the fuel cell 16 is outputting DC electricity, a start signal is input to the control unit 22. The input current maximum value control circuit 46 which has received the start signal issues an input current maximum value command to the switching control circuit 34 to start the start mode of the power generation system. Similarly, the output voltage gradient command circuit 36 that has received the start signal issues an output voltage gradient command to the switching control circuit 34 to start the start mode of the power generation system.

The switching control circuit 34 receives the output voltage data of the DC / DC converter 18 through the output voltage detection circuit 38 and the DC through the input current detection circuit 32.
It is possible to receive the input current data of the / DC converter 18 and simultaneously monitor the input current and the output voltage. Analog values may be used for the monitored input current and output voltage. You may use the digitized value. For the input current detection circuit 32 and the output voltage detection circuit 38, an AD converter that converts an analog value of current or voltage into a digital signal can be used.

FIG. 8 is a timing chart of the fuel cell power generation system according to the third embodiment of the present invention.
The switching control circuit 34 applies a narrow pulse to the gate of the switching element 28 to gradually increase the zero volt output voltage of the DC / DC converter 18 at the time indicated by the start in the figure. Then, a narrow pulse can be periodically applied to the gate of the switching element 28 to limit the input current to the set value.

As shown in the upper part of FIG. 8, the input current of the DC / AC inverter 40 is controlled so that it is zero ampere at the time of starting the DC / DC converter and rises with a predetermined gradient with the passage of time. ing. The slope of the input current of the DC / AC inverter 40, for example, rises from zero amps to about 10 amps, the smoothing capacitor 20 is fully charged, then returns to zero amps, and power is supplied at the rated operation. The charging / discharging of the smoothing capacitor 20 can be controlled to be repeated during the period.

The input current of the DC / DC converter 18 can be variously changed. The maximum value of the input current is the supply amount of hydrogen and oxygen to the fuel cell 16 and the rectifying diode 25 as a control component. It can be set from the maximum rated value of the dividing resistor 27 and the smoothing capacitor 20.

As described above, the fuel cell power generation system described in the embodiment of the present invention can prevent the inrush current generated at the time of starting the system, and the inrush current prevention mechanism does not require a large capacity resistor. Instead, the hardware logic control circuit or the software logic control circuit such as a microcomputer can be implemented at low cost and in a small space.

Further, since no inrush current is generated, damage and deterioration of the fuel cell can be reduced, and DC
It is possible to reduce damage and deterioration of electronic components that form the / DC converter 18 and the DC / AC inverter 40.

As a means to be applied to the embodiment of the present invention, the fuel cell 16 has, for example, a solid polymer membrane constituting an electrolyte, and a fuel electrode and a fuel electrode are provided on one surface side of the solid polymer membrane. A polymer electrolyte fuel cell having a fuel gas passage for supplying a fuel gas containing hydrogen as a main component and having an oxidizer electrode on the other surface side can be used.

It should be noted that the fuel cell power generation system of the present invention is not limited to the above illustrated example, and various modifications can be made without departing from the scope of the present invention. For example, the start-up mode can be executed in a state where direct current electricity is being output from the fuel cell 16, and when the fuel cell 16 is started in a state where no fuel and oxygen are supplied and no electrochemical reaction occurs. Even if there is, a timer or a fuel cell 16 output voltage detection device can be added to execute the automatic start mode.

[0056]

As described above, the first aspect of the present invention is as described above.
According to the fuel cell power generation system of any one of 3 to 3, DC / AC
Smoothing capacitor 2 connected to the input stage of the inverter 40
It is possible to effectively prevent damage or deterioration of the system by preventing an inrush current flowing into zero.

[Brief description of drawings]

FIG. 1 is a block diagram of a fuel cell power generation system according to an embodiment of the present invention.

FIG. 2 is a timing chart of the fuel cell power generation system according to the embodiment of the present invention.

FIG. 3 is a timing chart of the fuel cell power generation system according to the embodiment of the present invention.

FIG. 4 is a block diagram of a fuel cell power generation system according to an embodiment of the present invention.

FIG. 5 is a timing chart of the fuel cell power generation system according to the embodiment of the present invention.

FIG. 6 is a timing chart of the fuel cell power generation system according to the embodiment of the present invention.

FIG. 7 is a block diagram of a fuel cell power generation system according to an embodiment of the present invention.

FIG. 8 is a timing chart of the fuel cell power generation system according to the embodiment of the present invention.

FIG. 9 is a timing chart of a conventional fuel cell power generation system.

FIG. 10 is a conventional DC with an inrush current prevention circuit.
It is a block diagram of an / AC inverter.

FIG. 11 is a block diagram of a conventional fuel cell power generation system.

[Explanation of symbols]

7 Smoothing capacitor 10 reformer 11 resistors 12 Fuel gas 14 Oxidizer gas 16 Fuel cell 18 DC / DC converter 20 smoothing capacitor 22 Control unit 23 Input current detector 24 step-up transformer 25 Rectifier diode 26 Current smoothing reactor 27 division resistors 28 switching elements 30 driver circuit 32 Input current detection circuit 34 Switching control circuit 36 Output voltage gradient command circuit 38 Output voltage detection circuit 40 DC / AC inverter 42 switch transistor 46 Input current maximum value control circuit 100 Open / close controller 102 inverter 104 switch 110 Inrush current 112 Start signal

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Naohide Haga             1-6-34 Konan, Minato-ku, Tokyo Ebara Ballard             Within the corporation (72) Inventor Manabu Watanabe             1-6-34 Konan, Minato-ku, Tokyo Ebara Ballard             Within the corporation (72) Inventor Shoji Aoyama             1-6-34 Konan, Minato-ku, Tokyo Ebara Ballard             Within the corporation (72) Inventor Kazufumi Tateishi             1-6-34 Konan, Minato-ku, Tokyo Ebara Ballard             Within the corporation F-term (reference) 5H007 BB07 CA02 CB05 CB06 CC01                       CC03 DA05 DA06 DC02 DC05                       GA01                 5H026 AA06                 5H027 AA06 BA01 MM26

Claims (3)

[Claims] 1. A fuel cell that generates electricity by an electrochemical reaction between a fuel gas and an oxidant gas; a DC / DC converter that transforms a DC voltage output from the fuel cell into a predetermined DC voltage; and the DC / DC. A capacitor connected to the output side of the converter; said DC / DC converter comprising:
A control unit for controlling the DC / DC converter main body,
The control unit is configured to increase the output voltage with a predetermined gradient to boost the output voltage from zero to the predetermined DC voltage when the DC / DC converter is activated; a fuel cell power generation system. 2. A fuel cell that generates electricity by an electrochemical reaction between a fuel gas and an oxidant gas; a DC / DC converter that transforms a DC voltage output from the fuel cell into a predetermined DC voltage; and the DC / DC. A capacitor connected to the output side of the converter; said DC / DC converter comprising:
A control unit for controlling the DC / DC converter main body,
The control unit is configured to limit the input current of the DC / DC converter in order to boost the output voltage from zero to the predetermined DC voltage when the DC / DC converter is activated; a fuel cell power generation system. 3. A DC / AC inverter for converting a DC voltage output from the DC / DC converter into an AC voltage; the capacitor constitutes a part of the DC / AC inverter; 2. The fuel cell power generation system according to 2.