JP2007249341A - Hydrogen production system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wind power generation and hydrogen production system that stably supplies power from a wind power generation device to a load and a hydrogen production device. <P>SOLUTION: The absorption of power fluctuations of the wind power generation device in the hydrogen production device and the control of the current of the hydrogen production device can stabilize hydrogen production and suppress hydrogen production device degradation. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a hydrogen production apparatus, and more particularly to a hydrogen production apparatus that uses power obtained by wind power generation as an energy source.

  Currently, most of the energy that supports our lives is provided by fossil fuels, but in addition to the depletion of resources, there are issues such as global warming. One way to solve these problems is to use renewable energy such as wind, solar, and hydropower. However, these renewable energies have drawbacks such as low energy density and unstable energy supply. As a method for solving these problems, there is a method in which energy is temporarily converted into secondary energy called hydrogen and stored, and hydrogen is supplied in accordance with energy demand, thereby achieving a stable supply of energy. Furthermore, hydrogen energy also has the advantage that it can be easily stored compared to electrical energy.

  As a method for generating hydrogen using wind power and producing hydrogen stably and efficiently, the voltage supplied from the power generator to the hydrogen generator is controlled by controlling the wind turbine speed of the wind power generator with an exciter. There is a method of control.

JP 2004-269945 A

  When the stable supply of power to the load by wind power generation and the production of hydrogen are performed simultaneously, the load on the hydrogen production device fluctuates, resulting in unstable hydrogen production and repeated load fluctuations. This accelerates the deterioration of the hydrogen production apparatus.

  An object of the present invention is to provide a wind power generation hydrogen production apparatus that stably supplies power from a wind power generation apparatus to a load and a hydrogen production apparatus.

  A wind power generation hydrogen production apparatus having a wind power generation apparatus that supplies power to a load and an electrolytic hydrogen production apparatus that receives power supply from the wind power generation apparatus, and sets power to be supplied to a preset load as a target value, The wind power generation hydrogen production apparatus is characterized in that a difference between a power generation output generated by the wind power generation apparatus and the target value is supplied to the electrolytic hydrogen production apparatus.

  According to the wind power generation hydrogen production apparatus of the present invention, it is possible to provide a wind power generation hydrogen production apparatus that stably supplies power from the wind power generation apparatus to a load and a hydrogen production apparatus.

  This was realized by controlling the chopper circuit for controlling the power supplied to the hydrogen production device, the current control of the chopper circuit, and the windmill pitch angle of the wind power generator.

Embodiments for carrying out the present invention will be described below.
(1) In the wind turbine generator connected to the power grid, electrolytic hydrogen is supplied by supplying a predetermined power to the grid and using the difference between the generated power of the wind turbine generator and the target value power output to the grid as differential power. A hydrogen production system that produces hydrogen by supplying it to production equipment.
(2) In the above, the hydrogen production system which controls hydrogen production amount by controlling the electric power and electric current which are supplied to an electrolytic hydrogen production apparatus based on the operation state of an electrolytic hydrogen production apparatus.
(3) A hydrogen production system that uses a wind turbine generator capable of controlling the wind turbine pitch angle and controls the wind turbine pitch angle to keep the power generator output at a predetermined power.
(4) A hydrogen production system comprising at least a wind power generator, an electrolytic hydrogen production device, and an AC / DC converter for supplying the generated alternating current to the electrolytic hydrogen production device.
(5) In the above, the hydrogen production system which has a chopper circuit for controlling the electric power supplied to an electrolytic hydrogen production apparatus.
(6) An oxygen production system for producing oxygen in a wind turbine generator connected to an electric power system by supplying predetermined electric power to the electric power system and supplying surplus fluctuation power to the electrolytic oxygen production apparatus.

  As described above, the embodiment according to the present invention compares the power or current that can be supplied from the wind power generator with the operable power or current range of the hydrogen production apparatus in the hydrogen production system, and operates the hydrogen production apparatus. This is achieved by controlling the state. Furthermore, the embodiment according to the present invention is achieved by controlling the windmill pitch angle so that the rated power of the wind turbine generator or the optimum power depending on the wind speed is output.

  In the present embodiment, the load is an electric power system, but the load is not limited to the electric power system, and can be applied to uses such as factories and plants that require stable power supply.

  Moreover, although described as a hydrogen production apparatus in the following examples, when hydrogen is obtained by electrolysis of water, oxygen is also obtained at the same time. Therefore, in the following examples, an oxygen production apparatus is obtained by collecting generated oxygen.

  FIG. 1 is a configuration diagram of a wind power generation hydrogen production apparatus according to an embodiment of the present invention.

  The wind turbine generator includes a cage induction generator 2 and the like to which a wind turbine 1 capable of controlling the wind turbine pitch angle is connected, and is connected to an electric power system (infinite bus) via a two-line power transmission line 3. Here, a power factor adjusting phase-advancing capacitor 8 is installed at the terminal of the wind turbine generator, and the power factor is set to be approximately 1 at the rated output.

  The hydrogen production device 7 is connected to the power system via a Δ-Δ transformer 4, a three-phase full-wave rectifier circuit 5, and a step-down chopper circuit 6.

The step-down chopper circuit 6 is controlled by a pulse signal Gate Signal output from the chopper controller 55.
Chopper controller 55, the detected value of the current sensor 51 and voltage sensor 52, receives the output electric power P _w of a wind turbine generator, which is calculated by the power calculator 50. The voltage E ₂ of the hydrogen production device 7 is detected by the voltage sensor 54, and the current I ₂ flowing through the hydrogen production device 7 is detected by the current sensor 53 and input to the chopper control device 55.

  As the hydrogen production apparatus 7, a solid polymer electrolyte water electrolysis hydrogen production apparatus is used, and hydrogen is produced by consuming the fluctuating power of wind power by the hydrogen production apparatus 7 under the control of the step-down chopper circuit 6.

  Although an example of the step-down chopper circuit 6 will be described here, a step-up chopper circuit or a step-up / step-down chopper circuit may be used. Further, as a wind power generator, a description will be given using a device using a squirrel-cage induction generator here, but it can also be applied to a device using a synchronous generator, an AC excitation synchronous generator, a permanent magnet generator, or the like. . Further, the wind power generator may be a wind power generator composed of at least one unit. Furthermore, as a hydrogen production apparatus, a solid polymer electrolyte water electrolysis hydrogen production apparatus will be described here, but an alkaline water electrolysis hydrogen production apparatus, a brine electrolysis hydrogen production apparatus, a seawater electrolysis hydrogen production apparatus, and a steam electrolysis hydrogen production apparatus. May be.

FIG. 3 is a configuration diagram of the chopper control device 55 that drives the step-down chopper circuit 6. The differential power e between the wind power generation power P _w and the target value power P _k of the wind power generation power output to the grid is input to the PI controller 9. The PI controller 9 calculates a power target value P _t consumed by the hydrogen production device 7. Further, the electric power target value P _t is divided by the detected voltage value E ₂ to calculate a current command value I _t for the hydrogen production apparatus and output it to the comparison block (block A). The target value P _k may be changed in the apparatus under conditions such as an operation time zone, or the command value may be changed by transmission from the apparatus on the power system side.

On the other hand, the voltage E ₂ of the hydrogen production apparatus 7 is input to the maximum power value calculation block 11, and outputs the current value I _h allowed by the hydrogen production device 7 after the calculation to the comparison block (Block A). FIG. 4 is a diagram for explaining the operation of the power maximum value calculation block 11. In FIG. 4, when the current voltage E ₂ and current I ₂ are input, the state of the current-voltage characteristic of the hydrogen production apparatus (state B in the figure) is obtained by referring to a table or a calculation formula, and allowed at that time. A maximum current value I _{h max} and a minimum current value I _{h min} for hydrogen production are calculated and output as a current command value I _h . For example, if the state of the hydrogen production device changes and the current command value falls below the minimum value, or the current command value is changed and the current command value falls outside the range between the maximum and minimum values, the hydrogen production efficiency decreases. Therefore, it is necessary to limit the current command value within a predetermined range.

The comparison block 10 (block A) inputs the target current value I _t of the hydrogen production device 7, the maximum current value I _{h max} and the minimum current value I _{h min} allowed for hydrogen production, and I _t and I _{h max} , I _{h min} are compared, the value of the output signal Signal (1) is determined by the following formulas 1 and 2, and output to the switching block 57 (block B).
(Equation 1)
I _{h max} > I _t > I _{h min} : Signal (1) = 1
(Equation 2)
I _{h max} <I _t or I _t <I _{h min} : Signal (1) = 0
The switching block 57 (block B) inputs the input current command value I _t of the hydrogen production apparatus 7 and the input current command value I _h for permissible hydrogen production, and Signal (1) is “1”. when it outputs a current command value I _t from the switching unit 58 outputs a current command value I _h when the Signal (1) is "0" from the selector 58. That is, when the target current value I _t used for hydrogen production is out of the allowable range (I _{h max} > I _t > I _{h min} ) required for the hydrogen production apparatus, the allowable value I _h (I _{h max} or I _{h min} ) is selected.

  The current command value Iref output from the switch 58 is input to the current limiter 56.

  The current limiter 56 is composed of, for example, a first-order lag filter or a change rate limiter that suppresses the change rate within a predetermined value, and outputs a current command value Iref ′ that suppresses a steep fluctuation of the current command value Iref. The current command value Iref ′ is input to the current adjustment block 12 (block C).

The current adjustment block 12 inputs the deviation to the PI controller 9 in order to make the deviation between the current command value Iref ′ and the current I ₂ flowing through the hydrogen production device zero, and the command value Duty for driving the chopper circuit 6 is obtained. And output to the pulse generator PWM.

  The pulse generator PWM generates a pulse gate signal for turning on / off switching elements such as IGBTs constituting the chopper circuit 6 from the inputted command value Duty.

FIG. 5 is a block diagram for obtaining the wind turbine pitch angle command BETA. Assuming that the average wind speed at a certain time is u [m / s], the characteristic of the generated power with respect to the rotational speed is a characteristic having a maximum value. Therefore, when the average wind speed u is obtained, the optimum wind turbine rotational speed ωref can be obtained by referring to a table or calculating with a calculation formula. When the wind speed is high, the engine is operated at a rotational speed that does not reach the maximum efficiency point so that the generated power becomes a predetermined value _PRmax so that the generated power does not become larger than the generator rating. Therefore, the power generation characteristic indicated by the bold line in the figure is obtained. The predetermined value P _Rmax can be changed by the switch 59. For example, when the power consumption in the system is small such as at night and it is not desired to output wind power to the system, the rated capacity of the hydrogen production device If P _R is changed to P _Rchg considerably, the hydrogen output can be produced by the hydrogen production apparatus while the power output to the system is substantially zero, and the wind power generation apparatus does not have to be stopped.

  The deviation is calculated by subtracting the detected rotation speed value ω from the optimum windmill rotation speed ωref. The obtained deviation is input to the PI controller 9, and the pitch angle BETA of the windmill, which is the output of the PI controller 9, is adjusted so that the deviation becomes zero.

6, 7, and 8 show the pitch angle control operation shown in FIG. 5. FIG. 6 shows the wind speed, FIG. 7 shows the pitch angle BETA calculated at that time, and FIG. 8 shows the power generation output. By the pitch angle control, the electric power when the wind speed is high is controlled to a predetermined value (here, 50 MW).

  9, FIG. 10 and FIG. 11 show the operation of the system shown in FIG. 1 and FIG.

FIG. 9 shows the current I ₂ flowing through the hydrogen production apparatus. The maximum current value of the hydrogen production apparatus is suppressed within a predetermined value (14 kA in this case) by the control of the block B in FIG. 3, and below the predetermined value, the hydrogen production apparatus current is absorbed so as to absorb wind power fluctuations. It has changed.

FIG. 10 shows the amount of hydrogen production. It can be seen that hydrogen is produced according to the current value I ₂ shown in FIG.

FIG. 11 shows the active power output to the power system, and this value can be adjusted by the target value P _k of the wind power output to the system described in FIG. FIG. 11 shows a waveform when P _k = 30 MW, and the power output to the system can be controlled to approximately 30 MW.

As shown in the above embodiment, than the value of the wind generated power P _w, by decreasing the target value P _k of the wind generated power to be output to the system, power fluctuation component of power by the wind power generation is absorbed by the hydrogen generating device , A hydrogen production system capable of outputting almost constant power to the system can be provided.

  As shown in the above embodiment, by removing the steep fluctuation component of the current command value and controlling the current supplied to the hydrogen production apparatus, useless power consumption that does not contribute to hydrogen production can be suppressed.

  In addition, since the means for limiting the maximum value of the current command value to the maximum value determined by the state of the hydrogen production apparatus is provided, the deterioration of the hydrogen production apparatus can be prevented.

Further, by changing the maximum power value P _R for obtaining the pitch angle and the same as the target value P _k of the wind generated power output can adjust the power to be output to the system (e.g., the maximum power value P _R to the system The base of the power value output to the system can be controlled to be almost zero.)

  According to the above embodiments, the hydrogen production apparatus can absorb wind power fluctuations, so that fluctuations in power output to the system can be suppressed, hydrogen production can be performed stably, and hydrogen production can be performed. There is an effect of suppressing deterioration of the apparatus.

  Next, Example 2 will be described with reference to FIG. FIG. 2 is a single-line diagram showing a device configuration of another embodiment of the present invention. The same reference numerals as those in FIG.

  In the embodiment shown in FIG. 2, the wind power generator is connected to the system via an AC / DC converter 61 and an AC / DC converter 62.

  The hydrogen production device 7 is connected to the DC portion of the AC / DC converter 61 (or 62), and the current of the hydrogen production device 7 is adjusted by the chopper circuit 6 and the control device 55.

  According to the present embodiment, there is an effect equivalent to that of the first embodiment, and by connecting to the direct current portion, a rectifier circuit becomes unnecessary and the configuration is simplified.

  By comparing the output of the power generation device and the production status of the hydrogen production device, it is possible to suppress load fluctuations on the hydrogen production device. Applicable.

The block diagram of the wind power generation hydrogen production apparatus which is one Example of this invention. The block diagram of the wind power generation hydrogen production apparatus which is the other Example of this invention. The block diagram of a chopper control apparatus. Explanatory drawing for calculating | requiring the maximum electric power value of a hydrogen production apparatus. Explanatory drawing of a pitch angle control apparatus. Wind speed data. Changes in windmill pitch angle. Wind power generator output change. Current change in hydrogen production equipment. Changes in the amount of hydrogen generated in hydrogen production equipment. Change in output power to the power system.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Windmill, 2 ... Cage type | mold induction generator, 3 ... Two-line system power transmission line, 4 ... (DELTA) -delta transformer, 5 ... Three-phase full-wave rectifier circuit, 6 ... Step-down chopper circuit, 7 ... Hydrogen production apparatus, 8 Power phase adjustment phase advance capacitor, 9 PI controller, 10 Comparison block, 11 Maximum power calculation block, 12 Current adjustment block, 50 Power calculator, 51, 53 Current sensor, 52, 54 Voltage sensor, 55 ... chopper controller, 56 ... current limiter, 57 ... switching block, 58, 59 ... switch, 61, 62 ... AC / DC converter, 70 ... pitch controller.

Claims (13)

  A wind power generation hydrogen production apparatus having a wind power generation apparatus that supplies power to a load and an electrolytic hydrogen production apparatus that receives power supply from the wind power generation apparatus, and sets power to be supplied to a preset load as a target value, A wind power generation hydrogen production apparatus characterized in that a difference between a power generation output generated by the wind power generation apparatus and the target value is supplied to the electrolytic hydrogen production apparatus.   A wind power generation hydrogen production apparatus having a wind power generation apparatus that supplies power to a load and an electrolytic hydrogen production apparatus that receives power supply from the wind power generation apparatus, the means for detecting the power generation output of the wind power generation apparatus, and a detection And a control means for supplying a difference between the generated power output and a target value of power to be supplied to a preset load to the electrolytic hydrogen production apparatus.   3. The wind power according to claim 2, further comprising a control unit that makes the supply power to the electrolytic hydrogen production apparatus and the power output to the load have a predetermined power value based on the detected power generation output of the wind power generation apparatus. Power generation hydrogen production equipment.   As the control means, based on the power consumption of the electrolytic hydrogen production apparatus and / or the current command value flowing through the electrolytic hydrogen production apparatus calculated from the power allowed for the hydrogen production apparatus, the power supply circuit switching element of the hydrogen production apparatus The wind power generation hydrogen production apparatus according to claim 2, further comprising means for controlling an input current by controlling a gate signal.   5. The wind power generation hydrogen production apparatus according to claim 4, further comprising current limiting means for suppressing a steep fluctuation of the current command value.   A current command value changing means for limiting the current command value so as not to exceed a maximum current value determined by an operating state of the electrolytic hydrogen production apparatus, and changing a target value of an input current of the electrolytic hydrogen production apparatus. The wind power generation hydrogen production apparatus according to claim 4.   The wind power generation hydrogen production apparatus according to claim 1, wherein the wind power generation apparatus includes a windmill, and a pitch angle of the windmill can be controlled.   The wind power generation hydrogen production apparatus according to claim 7, further comprising means for changing a maximum power value that can be generated by the wind turbine generator from the rated power of the wind turbine generator according to the pitch angle.   The wind power generation hydrogen production device according to claim 1, further comprising a power conversion circuit for supplying alternating current generated by the wind power generation device to the electrolytic hydrogen production device.   The wind power generation hydrogen production apparatus according to claim 1, further comprising a power conversion circuit for connecting the power generated by the wind power generation apparatus to a load.   The wind power generation hydrogen production apparatus according to claim 1, further comprising a chopper circuit for controlling power supplied to the electrolytic hydrogen production apparatus.   The wind power generation hydrogen production apparatus according to claim 1, wherein the load is a power system.   A wind power generation hydrogen production apparatus having a wind power generation apparatus that supplies power to a load and an electrolytic oxygen production apparatus that receives power supply from the wind power generation apparatus, and sets power to be supplied to a preset load as a target value, A wind power generation oxygen production apparatus characterized in that a difference between a power generation output generated by the wind power generation apparatus and the target value is supplied to the electrolytic oxygen production apparatus.

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