JP2007242533A - Voltage converter for fuel cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To dissolve the problem requiring the design change of a booster circuit according to the change of the specification of a fuel cell. <P>SOLUTION: The booster circuit 12 is placed between the fuel cell 2 and an inverter 13 to boosts the DC voltage of a DC power from the fuel cell, and to supply the DC power of a boosted DC current to the inverter. The booster circuit 12 has two transducers 123 having a predetermined transformer ratio. A parallel circuit pattern 12A connecting the each input side wiring 121 of the two transformers in parallel, and a series circuit pattern 12B connecting the each input side wiring of the two transformers are preliminary prepared. One of the parallel circuit pattern or the series circuit pattern related to the range of the allowed input voltage corresponding to an output voltage range becomes possible to be selected according to the output voltage of the DC current generated by the fuel cell. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention is used, for example, in a power conditioner device (hereinafter simply referred to as a power conditioner device) of a fuel cell power generation system that links a fuel cell and a system power source and supplies power to a general load such as a home appliance. The present invention relates to a voltage converter for a fuel cell such as a booster circuit that boosts a DC voltage generated by the fuel cell between a fuel cell and an inverter and supplies the boosted DC voltage to an inverter.

  Conventionally, such a general fuel cell power generation system extracts, for example, hydrogen by reforming gas, kerosene, alcohol, etc., and reacts the extracted hydrogen with oxygen in the air to generate DC power. A fuel cell, a system power source such as a commercial power source, and a power conditioner device disposed between the fuel cell and the system power source and having an inverter function for converting DC power generated by the fuel cell. A booster circuit that boosts the DC voltage of the DC power from the battery, and an inverter that converts the DC power boosted by the booster circuit into AC power.

  The booster circuit inside the power converter device used in such a general fuel cell power generation system has an allowable input voltage range corresponding to the output voltage range of the DC power from the fuel cell, and within this allowable input voltage range. The DC power from the fuel cell can be input, the DC voltage of the DC power is boosted, and the DC power of the boosted DC voltage is supplied to the inverter.

  However, according to such a fuel cell power generation system, the specifications of the output voltage range of DC power generated according to the type and manufacturing method of the fuel cell and the amount of cells of the fuel cell differ from manufacturer to manufacturer. Depending on the specifications, the allowable input voltage range of the booster circuit arranged between the fuel cell and the inverter must be changed, so a design change including the boost ratio of the transformer inside the booster circuit is required, and the fuel cell system The fact is that you have to customize every time.

For example, as a prior art for changing the step-up ratio of the transformer, an output transformer including an inverter that converts the DC power of the fuel cell into AC power and an output transformer that converts the AC output voltage of the inverter is provided. Has a tap winding provided in the secondary winding and a tap selection unit for selecting a tap, and when the output voltage drops due to aging of the fuel cell, the tap transformer can be selected by selecting the tap. A device in which the ratio is increased to compensate for a decrease in output voltage is known (see, for example, Patent Document 1).
Japanese Patent Laid-Open No. 11-162491 (see abstract and FIG. 1)

  However, according to the voltage conversion device for a fuel cell disclosed in Patent Document 1, a booster circuit disposed between the fuel cell and the inverter is not the subject of the invention. In the first place, for example, a fuel cell having an output voltage range specification of 20V to 50V is 2 When the fuel cell is changed to a 40V to 100V output voltage range specification, the allowable input voltage range of the booster circuit is also changed from 20V to 50V specification to 40V to 100V specification, that is, the output accompanying the change of the fuel cell specification There is no function to adjust the allowable input voltage range of the booster circuit according to the change of the voltage range, and it is necessary to change the design including the boost ratio of the transformer inside the booster circuit according to the specification change of the fuel cell .

  The present invention has been made in view of the above points, and an object of the present invention is for a fuel cell that can flexibly cope with an allowable input voltage range of a booster circuit in accordance with a change in the output voltage range of the fuel cell. The object is to provide a voltage converter.

  In order to achieve the above object, a fuel cell voltage converter according to the present invention is disposed between a fuel cell and an inverter, boosts a DC voltage from the fuel cell, and supplies the boosted DC voltage to the inverter. A voltage conversion device for a fuel cell, in which a plurality of transformers having a predetermined transformation ratio are arranged, a parallel circuit pattern in which input-side wirings of the plurality of transformers are connected in parallel, and input-side wirings of the plurality of transformers are connected in series. The parallel circuit pattern or the series circuit pattern relating to an allowable input voltage range corresponding to the same voltage range according to a voltage range of DC power generated by the fuel cell It can be selected alternatively.

  Therefore, according to the voltage converter for a fuel cell of the present invention, a parallel circuit pattern in which the input side wirings of the plurality of transformers are connected in parallel, and a series circuit in which the input side wirings of the plurality of transformers are connected in series. The parallel circuit pattern or the series circuit pattern relating to the allowable input voltage range corresponding to the same voltage range can be alternatively selected according to the voltage range of the DC power generated by the fuel cell. For example, when the output voltage range of the fuel cell is 20V to 50V, the parallel circuit pattern is selected, and when the output voltage range of the fuel cell is 40V to 100V, the series circuit pattern is selected. The allowable input voltage range of the booster circuit can be flexibly accommodated without changing the design of the booster circuit in accordance with the change of the voltage range.

  The voltage conversion device for a fuel cell according to the present invention includes a selection unit that selectively selects the parallel circuit pattern or the series circuit pattern, and a voltage conversion unit configured to select a DC power generated by the fuel cell. Control means for controlling the selection means is provided to selectively select the parallel circuit pattern or the series circuit pattern related to the allowable input voltage range corresponding to the voltage amount.

  Therefore, according to the voltage conversion device for a fuel cell of the present invention, according to the voltage range of DC power generated by the fuel cell, the parallel circuit pattern or the parallel circuit pattern related to the allowable input voltage range corresponding to the same voltage range. The series circuit pattern is automatically selected. For example, when the output voltage range of the fuel cell is 20V to 50V, the parallel circuit pattern is selected, and when the output voltage range of the fuel cell is 40V to 100V, the series circuit pattern is selected. By selecting, the allowable input voltage range of the booster circuit can be flexibly dealt with without changing the design of the booster circuit according to the change of the output voltage range of the fuel cell.

  According to the fuel cell voltage converter of the present invention configured as described above, the parallel circuit pattern in which the input-side wirings of the plurality of transformers are connected in parallel and the input-side wirings of the plurality of transformers are connected in series. The parallel circuit pattern or the series circuit pattern related to the allowable input voltage range corresponding to the same voltage range is selected according to the voltage range of the DC power generated by the fuel cell. For example, when the output voltage range of the fuel cell is 20V to 50V, the parallel circuit pattern is selected. When the output voltage range of the fuel cell is 40V to 100V, the series circuit pattern is selected. According to the change in the output voltage range of the fuel cell, the allowable input voltage range of the booster circuit can be flexibly accommodated without requiring a design change of the booster circuit Kill.

  Hereinafter, a fuel cell power generation system showing an embodiment relating to a voltage converter for a fuel cell of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a schematic configuration inside the fuel cell power generation system according to the present embodiment.

  A fuel cell power generation system 1 shown in FIG. 1 is, for example, a fuel cell 2 that generates direct-current power by reforming gas, kerosene, alcohol, or the like to extract hydrogen and reacting the extracted hydrogen with oxygen in the air. And an inverter function that is arranged between the system power source 3 such as a commercial power source, the fuel cell 2 and the system power source 3 and converts the DC power generated by the fuel cell 2 into AC power, and for example, a power failure on the system power source 3 side. A power conditioner 4 having a monitoring function for monitoring and a main controller 5 for controlling the entire fuel cell power generation system 1 are provided.

  The power converter device 4 includes a first filter 11 that performs a filtering process on the DC power from the fuel cell 2, a booster circuit 12 that boosts a DC voltage of the DC power that has been filtered by the first filter 11, Between the inverter 13 that converts the DC power of the DC voltage boosted by the booster circuit 12 into AC power, the second filter 14 that filters the AC power converted by the inverter 13, and between the fuel cell 2 and the system power supply 3 A system-side switch 15 that electrically connects or disconnects, a memory unit 16 that stores various information, a communication interface 17 that communicates and connects with the main controller 5, a control device 18 that controls the entire power control device 4, A control power supply 19 that supplies control power to the control device 18 and the communication interface 17, and a grid-side power supply that supplies power from the grid power supply 3 And a 20.

  The system-side power supply unit 20 rectifies the AC power transformed by the insulation transformer 21 into DC power, and rectifies the DC power into DC power. And a rectifier 22 that supplies power to the control power source 19 through 23.

  For example, when the fuel cell 2 is generating power, the control device 18 electrically connects the fuel cell 2 and the system power source 3 through the system-side switch 15 and detects the power generation stop of the fuel cell 2, for example. The electrical connection between the fuel cell 2 and the system power supply 3 is cut off through the switch 15.

  Further, when the fuel cell 2 is generating power, the control power source 19 extracts DC power generated by the fuel cell 2 between the first filter 11 and the booster circuit 12, and controls the extracted DC power as control power. This is supplied to the device 18 and the communication interface 17.

  Further, when the power generation of the fuel cell 2 is stopped, the control power source 19 cuts off the electrical connection between the fuel cell 2 and the system power source 3 through the system side switch 15, thereby supplying AC power from the system power source 3 to the system. The DC power is converted to DC power through the insulating transformer 21, the rectifier 22 and the reverse current diode 23 in the side power supply unit 20, and this DC power is supplied to the control device 18 and the communication interface 17 as control power.

  FIG. 2 is an explanatory diagram showing a schematic configuration inside the booster circuit 12 of the power control device 4.

  The booster circuit 12 shown in FIG. 2 includes two transformers 123 having an input-side wiring 121 and an output-side wiring 122 and having a predetermined transformation ratio, and connects the input-side wirings 121 of the trunks 123 in parallel. A circuit pattern 12A (see FIG. 2A) and a series circuit pattern 12B (see FIG. 2B) for connecting the input-side wirings 121 of the trunks 123 in series are provided. The circuit pattern 12B can be alternatively selected.

  The booster circuit 12 shown in FIG. 2A shows a case where the parallel circuit pattern 12A is selected. The input circuit wirings 121 of the transformer 123 are connected in parallel to form a large current circuit. The DC power is supplied to each transformer 123 by increasing the amount of current while maintaining a constant voltage amount of the DC power, and each transformer 123 converts the DC voltage of the DC power to a predetermined voltage (based on a command from the controller 18). For example, the voltage is boosted to 330 V), and the boosted DC power is supplied to the inverter 13.

  The booster circuit 12 shown in FIG. 2B shows a case where the series circuit pattern 12B is selected. The high-voltage circuit is configured by connecting the input-side wirings 121 of the transformer 123 in series. The DC power is supplied to each transformer 123 by increasing the amount of voltage while maintaining a constant current amount of the DC power, and each transformer 123 converts the DC voltage of the DC power to a predetermined voltage (based on a command from the controller 18). For example, the voltage is boosted to 330 V), and the boosted DC power is supplied to the inverter 13.

  The fuel cell voltage converter is the booster circuit 12, the fuel cell is the fuel cell 2, the inverter is the inverter 13, the transformer is the transformer 123, the input side wiring is the input side wiring 121, and the series circuit pattern is the series circuit pattern. 12B, the parallel circuit pattern corresponds to the parallel circuit pattern 12A, the selection means corresponds to the pattern switching unit 30, and the control means corresponds to the control device 18.

  Next, operation | movement of the fuel cell power generation system 1 which shows this Embodiment is demonstrated.

  For convenience of explanation, the output voltage range of the fuel cell 2 in use in the fuel cell power generation system 1 is 20 V to 50 V, and the booster circuit 12 has an allowable input voltage range of 20 V to 20 V depending on the output voltage range of the fuel cell 2. It is assumed that the parallel circuit pattern 14A of 50V is selected.

  At this time, since the booster circuit 12 selects the parallel circuit pattern 12A, the allowable input voltage range corresponds to the specification of the output voltage range (20V to 50V) of the fuel cell 2, and the DC power from the fuel cell 2 is increased. Can be entered.

  Furthermore, the booster circuit 12 selects the parallel circuit pattern 12A and connects the input-side wirings 121 of the transformers 123 in parallel to form a large current circuit. The current amount is increased and supplied to each transformer 123 while maintaining a constant voltage amount with respect to the direct current power.

  When the fuel cell 2 having an output voltage range of 20V to 50V specification being used in the fuel cell power generation system 1 is changed to the fuel cell 2 having an output voltage range of 40V to 100V specification, the booster circuit 12 has an allowable input voltage range. By selecting the series circuit pattern 14B that sets 40V to 100V, the allowable input voltage range corresponds to the specification of the output voltage range (40V to 100V) of the fuel cell 2, and DC power from the fuel cell 2 is input. Can do.

  Further, the booster circuit 12 selects the series circuit pattern 12B and connects the input-side wirings 121 of the transformers 123 in series to form a high voltage circuit. The voltage amount is increased and supplied to each transformer 123 while maintaining a constant current amount with respect to the direct current power.

  According to the present embodiment, the parallel circuit pattern 12A in which the input-side wirings 121 of the two transformers 123 are connected in parallel, and the series circuit pattern 12B in which the input-side wirings 121 of the two transformers 123 are connected in series. In accordance with the output voltage range of the DC power generated by the fuel cell 2, the parallel circuit pattern 12A or the series circuit pattern 12B relating to the allowable input voltage range corresponding to the output voltage range is alternatively selected. For example, when the output voltage range of the fuel cell 2 is 20V to 50V, the parallel circuit pattern 12A is selected. When the output voltage range of the fuel cell 2 is 40V to 100V, the series circuit pattern 12B is selected. Without changing the design, the allowable input voltage range of the booster circuit 12 can be flexibly handled according to the change of the output voltage range of the fuel cell 2. It is possible.

  Further, according to the present embodiment, when the series circuit pattern 12B is selected, the high voltage circuit that increases the voltage amount functions while maintaining the constant current amount, and when the parallel circuit pattern 12A is selected, the constant voltage amount is maintained. Accordingly, since the large current circuit that increases the amount of current functions, the function of the high voltage circuit or the large current circuit can be flexibly added according to the specifications of the fuel cell 2.

  In the above embodiment, the parallel circuit pattern 12A in which the input-side wirings 121 of the two transformers 123 are connected in parallel and the series circuit pattern in which the input-side wirings 121 of the two transformers 123 are connected in series. 12B is selected alternatively, but the number of transformers 123 may be N, and as shown in FIG. 3B, the input-side wirings 121 of the N transformers 123 are connected in parallel. The connected parallel circuit pattern 12A and the series circuit pattern 12A in which the input-side wirings 121 of the N transformers 123 are connected in series as shown in FIG. In addition, various specifications of the fuel cell 2 and the inverter 13 can be supported.

  Moreover, in the said embodiment, as shown in FIG. 4, the pattern switching part 30 which carries out the switching connection of the input side wirings 121 of the two transformers 123 inside the booster circuit 12 in parallel or in series is provided. The internal control device 18 switches and controls the pattern switching unit 30 that switches and selects the parallel circuit pattern 12A or the series circuit pattern 12B of the booster circuit 12 according to the voltage amount of the DC power generated by the fuel cell 2. In this case, the selection operation of the series circuit pattern 12B or the parallel circuit pattern 12A can be automated.

  According to the fuel cell voltage converter of the present invention configured as described above, the parallel circuit pattern in which the input-side wirings of the plurality of transformers are connected in parallel and the input-side wirings of the plurality of transformers are connected in series. The parallel circuit pattern or the series circuit pattern related to the allowable input voltage range corresponding to the same voltage range is selected according to the voltage range of the DC power generated by the fuel cell. For example, when the output voltage range of the fuel cell is 20V to 50V, the parallel circuit pattern is selected. When the output voltage range of the fuel cell is 40V to 100V, the series circuit pattern is selected. The allowable input voltage range of the booster circuit can be flexibly accommodated according to changes in the output voltage range of the fuel cell, for example, used in a fuel cell power generation system Useful for boosting circuit within that power conditioner.

It is a block diagram which shows schematic structure inside the fuel cell power generation system which shows embodiment of the voltage converter for fuel cells of this invention. It is a block diagram which shows schematic structure of the step-up circuit which is the principal part of the power converter apparatus in connection with this Embodiment. a) When the input side wirings of two transformers are connected in parallel (parallel circuit pattern) b) When the input side wirings of two transformers are connected in series (series circuit pattern) It is a block diagram which shows schematic structure of the pressure | voltage rise circuit which is the principal part of the power inverter apparatus in connection with other embodiment. a) When the input side wirings of N transformers are connected in parallel (parallel circuit pattern) b) When the input side wirings of N transformers are connected in series (series circuit pattern) It is a block diagram which shows schematic structure of the pressure | voltage rise circuit which is the principal part of the power inverter apparatus in connection with other embodiment.

Explanation of symbols

2 Fuel cell 12 Booster circuit (Fuel cell voltage converter)
12A Parallel circuit pattern 12B Series circuit pattern 13 Inverter 18 Control device (control means)
30 pattern switching unit (selection means)
121 Input side wiring 123 Transformer

Claims (2)

A fuel cell voltage converter that is arranged between a fuel cell and an inverter, boosts a DC voltage from the fuel cell, and supplies the boosted DC voltage to the inverter,
Arrange multiple transformers with a predetermined transformation ratio,
A parallel circuit pattern for connecting the input side wirings of the plurality of transformers in parallel, and a series circuit pattern for connecting the input side wirings of the plurality of transformers in series are provided in advance,
According to a voltage range of DC power generated by the fuel cell, the parallel circuit pattern or the series circuit pattern related to an allowable input voltage range corresponding to the voltage range can be alternatively selected. A fuel cell voltage converter. A selection means for alternatively selecting the parallel circuit pattern or the series circuit pattern;
The selection means for alternatively selecting the parallel circuit pattern or the series circuit pattern related to the allowable input voltage range corresponding to the voltage amount according to the voltage amount of DC power generated by the fuel cell. 2. The fuel cell voltage converter according to claim 1, further comprising control means for controlling the fuel cell.

Images