Photovoltaic power generation direct-driven CO2 modular power supply control method, device and power supply system

Abstract

The present invention belongs to the field of power electronics technology, and provides a direct-drive photovoltaic power generation CO2 modular power supply control method, device and power supply system. First, the overall structure of the system is elaborated in detail. According to the changes in the photovoltaic output characteristics and the working characteristics of the electrolytic cell, the number of electrolytic cell modules and the power supply voltage are flexibly controlled to achieve power balance in the system. Then, the top-level optimization strategy during the system operation process is described, and the system operation process is designed, aiming to finally achieve the stable operation of the modular electrolytic cell power supply system. Finally, the control method is designed based on the system structure and operation strategy. Taking a two-unit electrolytic cell power supply system as an example and using an energy storage unit for auxiliary power supply, the control strategy is analyzed, and finally the external voltage of the electrolytic cell is flexibly controlled to enable the normal progress of electrocatalysis to meet the expected requirements.

Description

Technical Field

[0001] The present invention belongs to the field of power electronics technology, and in particular relates to a photovoltaic power generation direct-driven CO2 modular power supply control method, device and power supply system. Background Art

[0002] The statements in this section merely provide background information related to the present invention and do not necessarily constitute prior art.

[0003] With the continuous improvement of environmental awareness and the increasing prominence of global climate change, renewable energy has gradually become the main direction of global energy transformation. However, since the power generation of renewable energy is related to meteorological conditions, it is difficult to control and has large fluctuations. With the rapid development of renewable energy, its absorption problem has become increasingly prominent. At the same time, how to reduce carbon emissions and control carbon emissions in the chemical industry has also become a major problem.

[0004] In order to solve these problems, power storage technology has developed rapidly, effectively solving the problem of large volatility and difficulty in controlling renewable energy. CO2 capture technology and its electrocatalytic technology are also developing rapidly. Capturing CO2 and converting it into multi-carbon fuels through electrocatalysis can not only effectively recycle CO2, but also reduce the demand for fossil fuels and reduce carbon emissions. Combining the two, using renewable energy to drive the one-step conversion of tail gas CO2 from high-carbon emission industries into multi-carbon fuels, avoiding a single path for electricity consumption, can significantly improve the renewable energy consumption capacity, reduce energy consumption, and reduce carbon emissions.

[0005] However, there are many challenges in the process of using renewable energy to drive CO2 electrolyzers to convert into multi-carbon fuels. The voltage range of photovoltaic power generation is approximately between 200-400V, but the power supply voltage range of the electrolyzer is only 4-6V. In order to avoid overcurrent damage to the electrolyzer caused by large currents, achieve the maximum power output of photovoltaics, reduce energy loss, and facilitate flexible regulation, the CO2 electrolyzer needs to be modularized. However, how to achieve modular cluster control of electrolyzers is a major problem. Current modular cluster control technologies, such as MMC, mainly serve high-voltage direct current transmission and grid-connected technologies, and are also widely used in battery energy storage technologies, but none of them involve combining the use of renewable energy with the power supply of CO2 electrolyzers for control. Summary of the invention

[0006] In order to solve at least one technical problem existing in the above-mentioned background technology, the present invention provides a photovoltaic power generation direct-driven CO2 modular power supply control method, device and power supply system, which directly applies photovoltaic power generation to the CO2 electrolyzer, reduces energy loss in the intermediate process, and at the same time reduces carbon emissions and improves the renewable energy absorption capacity.

[0007] In order to achieve the above object, the present invention adopts the following technical solution:

[0008] A first aspect of the present invention provides a photovoltaic power generation direct-driven CO2 modular power supply control method, comprising the following steps:

[0009] Estimate the number of electrolyzers and energy storage modules required for the PV system based on the rated output power of the PV system, the power required by the electrolyzer, and the capacity of the energy storage module;

[0010] During the operation of the photovoltaic system, the number of electrolyzer modules that can consume the corresponding power and the number of energy storage modules that need to be operated are calculated based on the output power of the photovoltaic system and the power required by the electrolyzer;

[0011] For the electrolyzer module, the output voltage of the first electrolyzer power supply unit is controlled according to the output voltage loop, and the remaining electrolyzer power supply units use the input voltage loop control loop to calculate the input voltage reference value of the electrolyzer;

[0012] For the energy storage module, the input voltage of the energy storage module is determined according to the output power of the photovoltaic system and the input voltage reference value of the electrolyzer, thereby controlling the charging and discharging of the energy storage module.

[0013] Furthermore, the calculation method for the number of electrolyzers and energy storage modules required for the photovoltaic system is:

[0014] ,

[0015] ,

[0016] Where M is the number of electrolyzers required for the photovoltaic system. P out is the rated output power of the photovoltaic system, P work is the power required by the electrolyzer, X is the number of spare electrolyzer modules; N is the number of energy storage modules required for the photovoltaic system, P str_capa is the capacity of the energy storage module, and Y is the energy storage ratio of the new energy power station.

[0017] Furthermore, the method of calculating the number of electrolyzer modules that can consume the corresponding power and the number of energy storage modules that need to be operated according to the obtained output power of the photovoltaic system and the power required by the electrolyzer includes:

[0018] Calculate the absolute value of the maximum output power difference between the current moment and the previous moment;

[0019] Determine the absolute value and the power required by the electrolytic cell:

[0020] If the absolute value is greater than the power required by the electrolyzer, determine whether the maximum output power difference between the current moment and the previous moment is greater than 0. If it is greater than 0, calculate the number of electrolyzer modules invested and the power that needs to be stored in the energy storage module based on the maximum output power difference between the current moment and the previous moment and the power required by the electrolyzer; otherwise, calculate the number of electrolyzers to be bypassed and the power that needs to be released by the energy storage module based on the absolute value and the power required by the electrolyzer;

[0021] If the absolute value is less than the power required by the electrolyzer, determine whether the maximum output power difference between the current moment and the previous moment is greater than 0. If it is greater than 0, the energy storage module needs to store the power corresponding to the maximum output power difference between the current moment and the previous moment. Otherwise, the energy storage module needs to release the power corresponding to the output power difference.

[0022] Furthermore, the control method further includes:

[0023] Obtaining the operating voltage of the electrolyzer module;

[0024] Determine whether the cell voltage fluctuation range exceeds the set fluctuation range;

[0025] If exceeded, the corresponding electrolyzer module is a bypass fault module, and the upper and lower power switch devices of the same bridge arm of the DC / DC module of the power supply circuit of the module are controlled to be turned on at the same time, bypassing the faulty electrolyzer and putting into use an electrolyzer with the same power that has been repaired, and marking the bypassed electrolyzer as waiting for maintenance;

[0026] If it is not exceeded, the corresponding electrolyzer module can be put into use.

[0027] Furthermore, the calculation formula of the input voltage reference value of the electrolytic cell is:

[0028] ,

[0029] Where s is the serial number of the electrolyzer power supply module, The input voltage of the electrolyzer power supply module, It is the input voltage reference value of the electrolyzer power supply module. is the supply voltage of the electrolyzer, is the equivalent impedance of the electrolytic cell, The input voltage of the electrolyzer power supply module with serial number 1, The equivalent impedance of the electrolyzer power supply module is number 1, The supply voltage of the electrolytic cell with serial number 1 of the electrolytic cell power supply module.

[0030] Furthermore, the calculation formula of the input voltage of the energy storage module is:

[0031] ,

[0032] in, is the serial number of the energy storage module, is the input voltage of the energy storage module.

[0033] A second aspect of the present invention provides a photovoltaic power generation direct-driven CO2 modular power supply control device, comprising:

[0034] The system configuration module is used to estimate the number of electrolyzers and energy storage modules required for the photovoltaic system based on the rated output power of the photovoltaic system, the power required by the electrolyzer, and the capacity of the energy storage module;

[0035] The operation quantity optimization module is used to calculate the number of electrolyzer modules that can consume the corresponding power and the number of energy storage modules that need to be operated during the operation of the photovoltaic system according to the output power of the photovoltaic system and the power required by the electrolyzer;

[0036] The power supply control module is used to control the output voltage of the first electrolyzer power supply unit according to the output voltage loop for the electrolyzer module, and the other electrolyzer power supply units use the input voltage loop control circuit to calculate the input voltage reference value of the electrolyzer; for the energy storage module, the input voltage of the energy storage module is determined according to the output power of the photovoltaic system and the input voltage reference value of the electrolyzer, thereby controlling the charging and discharging of the energy storage module.

[0037] Furthermore, the device further comprises a fault judgment module, and the fault judgment module is configured to:

[0038] Obtaining the operating voltage of the electrolyzer module;

[0039] Determine whether the cell voltage fluctuation range exceeds the set fluctuation range;

[0040] If exceeded, the corresponding electrolyzer module is a bypass fault module, and the upper and lower power switch devices of the same bridge arm of the DC / DC module of the power supply circuit of the module are controlled to be turned on at the same time, bypassing the faulty electrolyzer and putting into use an electrolyzer with the same power that has been repaired, and marking the bypassed electrolyzer as waiting for maintenance;

[0041] If it is not exceeded, the corresponding electrolyzer module can be put into use.

[0042] Furthermore, in the operation quantity optimization module, the number of electrolyzer modules that can consume the corresponding power and the number of energy storage modules that need to be operated are calculated based on the obtained output power of the photovoltaic system and the power required by the electrolyzer, including:

[0043] Calculate the absolute value of the maximum output power difference between the current moment and the previous moment;

[0044] Determine the absolute value and the power required by the electrolytic cell:

[0045] If the absolute value is greater than the power required by the electrolyzer, determine whether the maximum output power difference between the current moment and the previous moment is greater than 0. If it is greater than 0, calculate the number of electrolyzer modules invested and the power that needs to be stored in the energy storage module based on the maximum output power difference between the current moment and the previous moment and the power required by the electrolyzer; otherwise, calculate the number of electrolyzers to be bypassed and the power that needs to be released by the energy storage module based on the absolute value and the power required by the electrolyzer;

[0046] If the absolute value is less than the power required by the electrolyzer, determine whether the maximum output power difference between the current moment and the previous moment is greater than 0. If it is greater than 0, the energy storage module needs to store the power corresponding to the maximum output power difference between the current moment and the previous moment, otherwise the energy storage module needs to release the power corresponding to the output power difference. A third aspect of the present invention provides a photovoltaic power generation direct-drive CO2 modular power supply system, comprising an electrolyzer module, an energy storage module, and a photovoltaic power generation direct-drive CO2 modular power supply control system as described in Example 2.

[0047] Compared with the prior art, the present invention has the following beneficial effects:

[0048] 1. The present invention combines the use of renewable energy with the power supply of the CO2 electrolyzer, and flexibly controls the external voltage of the electrolyzer through a modular control method to achieve normal electrocatalysis and meet expected requirements.

[0049] 2. The present invention adopts the method of input series connection and output parallel connection to combine the utilization of renewable energy with electrocatalysis, simplifying the intermediate steps to realize the power supply of renewable energy direct-driven electrolyzer.

[0050] 3. The present invention integrates the electrolyzer and energy storage into the photovoltaic power generation system at the same time, so that the entire system can flexibly dispatch power when the output power of the photovoltaic power generation system changes, thereby achieving normal operation of electrocatalysis.

[0051] Advantages of additional aspects of the present invention will be given in part in the following description, and in part will become obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0053] Figure 1 This is a flow chart of a photovoltaic power generation direct-driven CO2 modular power supply control method provided by an embodiment of the present invention;

[0054] Figure 2 A modular electrolyzer power supply system provided by an embodiment of the present invention;

[0055] Figure 3 is a flow chart of an electrolytic cell operation quantity optimization strategy provided by an embodiment of the present invention;

[0056] Figure 4 This is a block diagram of a power supply control strategy provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0057] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0058] It should be noted that the following detailed descriptions are all illustrative and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0059] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0060] Embodiment 1

[0061] like Figure 1 As shown, this embodiment provides a photovoltaic power generation direct-driven CO2 modular power supply control method, including the following steps:

[0062] Step 1: Estimate the number of electrolyzers and energy storage modules required for the PV system based on the rated output power of the PV system, the power required by the electrolyzer, and the capacity of the energy storage module;

[0063] Step 2: During the operation of the photovoltaic system, the number of electrolyzer modules that can consume the corresponding power and the number of energy storage modules that need to be operated are calculated based on the obtained output power of the photovoltaic system and the power required by the electrolyzer;

[0064] Step 3: For the electrolyzer module, the output voltage of the first electrolyzer power supply unit is controlled according to the output voltage loop, and the remaining electrolyzer power supply units adopt the input voltage loop control loop to calculate the input voltage reference value of the electrolyzer;

[0065] For the energy storage module, the input voltage of the energy storage module is determined according to the output power of the photovoltaic system and the input voltage reference value of the electrolyzer, thereby controlling the charging and discharging of the energy storage module.

[0066] Through the above modular control method, the external voltage of the electrolyzer can be flexibly controlled to ensure that the electrocatalysis proceeds normally and meets the expected requirements.

[0067] like Figure 2 The figure shows a modular electrolyzer power supply system. In order to reduce the voltage stress of the switch tube, the input end is connected in series, and the DC / DC unit is connected in parallel to expand the output power range; the load side is connected to a corresponding number of electrolyzer modules and energy storage units. This constitutes a photovoltaic direct-driven modular electrolyzer power supply system.

[0068] According to the changes in photovoltaic output characteristics and the working characteristics of the electrolyzer, the number of electrolyzer modules and the supply voltage are flexibly controlled to achieve power balance of the system.

[0069] According to the rated output power of the photovoltaic system P out and the power required by the electrolyzer P work , the number of electrolyzers M that the system needs to configure is estimated, as shown in formula (1). The formula reserves X spare electrolyzer modules in case the output power of the photovoltaic system increases and the electrolyzer needs to be put into use again or the working electrolyzer needs to be repaired.

[0070] (1),

[0071] According to the energy storage device configuration standard, the energy storage ratio of the new energy power station is configured. For example, the new energy power station is required to configure no less than 10% of energy storage. In order to make the electrolyzer still work at night, it is configured according to the ratio Y (Y ≥ 10%). Suppose the capacity of the energy storage module is P str_capa , the number of energy storage modules N that the system needs to configure can be estimated, as shown in formula (2):

[0072] (2),

[0073] like Figure 3 The schematic diagram of the method for optimizing the number of electrolytic cell operations is shown, which includes the following steps:

[0074] Step 201: monitor the output power change of the photovoltaic system in real time, and calculate the number of electrolyzer modules that can consume the corresponding power and the number of energy storage modules that need to be operated according to the output power of the photovoltaic system and the power required by the electrolyzer;

[0075] In this embodiment, according to the initial maximum output power of the photovoltaic system P out_max and the power required by the electrolyzer P work The ratio of is rounded to calculate the number of electrolyzer modules m (m<M) that can consume the corresponding power.P out_max Substituting into formula (2), the number of energy storage modules that need to be operated, n (n < N), is obtained.

[0076] During operation, the power difference Δ between the current sampling and the previous sampling of the maximum output power is calculated in real time. P out , compared with Δ P out The absolute value of P work :

[0077] When |Δ P out |> P work When Δ P out >0, put into use a corresponding number of electrolyzer modules, calculate the power that needs to be stored in the energy storage module, and adjust the operating state of the system, as shown in formula (3).

[0078] (3),

[0079] Among them, Δ m is the number of electrolytic cells put into operation again, given by Δ P out and P work The ratio of is rounded to get the integer; P store is the power that needs to be stored in the energy storage module.

[0080] If Δ P out <0, bypass the corresponding number of electrolyzers, calculate the power that needs to be released by the energy storage module, and adjust the operating state of the system, as shown in formula (4).

[0081] (4),

[0082] Among them, Δ n is the number of electrolytic cells that need to be bypassed, given by |Δ P out |with P work The ratio of is rounded to get the integer; P release The power that needs to be released by the energy storage module.

[0083] When |Δ P out |< P work When Δ P out >0, Pstore =Δ P out , the energy storage module needs to store the corresponding power; if Δ P out <0, P release =Δ P out , the energy storage module needs to release the corresponding power.

[0084] Step 202: monitor the working voltage of the electrolytic cell in real time. If the cell voltage fluctuation range exceeds the set normal fluctuation range, determine that the module is a faulty module in operation state, control the upper and lower power switch devices of the same bridge arm of the DC / DC module of the power supply circuit of the module to be turned on at the same time, bypass the faulty electrolytic cell, and put into use an electrolytic cell with the same power that has been repaired, and at the same time repair the bypassed electrolytic cell so that it can be put into use again;

[0085] The electrolytic cell bypassed in step 201 due to the change in photovoltaic output power is repaired to ensure that it can be put into use again at any time.

[0086] In step 3, taking the power supply system with m-unit electrolyzer power supply modules and n-unit energy storage modules in parallel as an example, the corresponding control strategy is designed, such as Figure 4 shown.

[0087] Step 301, first is the control strategy of the electrolyzer module, such as Figure 4 As shown in the figure, the output voltage loop is designed to control the output voltage of the electrolyzer power supply unit with sequence number 1. V ref,1 Output reference voltage value, according to the working voltage required by the electrolytic cell V work The other electrolyzer power supply units adopt the input voltage loop control loop. Since the duty cycle is negatively correlated with the input voltage during the input voltage loop regulation process, a negative gain is added to the control loop.

[0088] According to the power balance formula, ignoring device losses, under stable operation, formula (5) can be written as:

[0089] (5),

[0090] in, s is the serial number of the electrolyzer power supply module, The input voltage of the electrolyzer power supply module, The input current of the electrolyzer power supply module, is the conversion efficiency of the DC / DC converter, is the output voltage of the DC / DC converter and also the supply voltage of the electrolyzer. is the equivalent impedance of the electrolytic cell.

[0091] The input of each unit is connected in series. Under stable operation, the input current of each unit is equal and the working voltage of each electrolyzer is V work It is known that the output voltage of each unit is V o,s satisfy V o,s = V work , its input voltage reference value V ref,s The output voltage of each unit can be V o,s And the equivalent impedance of the electrolytic cell R o,s As shown in formula (6):

[0092] (6),

[0093] in, The input voltage of the electrolyzer power supply module with serial number 1, The equivalent impedance of the electrolyzer power supply module is number 1, The supply voltage of the electrolytic cell with serial number 1 of the electrolytic cell power supply module.

[0094] Step 302: For the control of the energy storage module, add the MPPT controller as the outer loop control to enable the photovoltaic system to achieve maximum power output. The inner loop adopts input voltage control. The voltage at the maximum power point is the overall input voltage of the input series side. V in , according to the change of photovoltaic output power and the input voltage of other electrolyzers, determine the reference value of energy storage module input voltage V ref,l ( l = 1,2,…,n), as shown in formula (7), thereby controlling the input voltage of the energy storage module and further controlling the charging and discharging process of the energy storage module.

[0095] (7),

[0096] in, is the serial number of the energy storage module, is the input voltage of the energy storage module.

[0097] Embodiment 2

[0098] This embodiment provides a photovoltaic power generation direct-driven CO2 modular power supply control device, including:

[0099] The system configuration module is used to estimate the number of electrolyzers and energy storage modules required for the photovoltaic system based on the rated output power of the photovoltaic system, the power required by the electrolyzer, and the capacity of the energy storage module;

[0100] The operation quantity optimization module is used to calculate the number of electrolyzer modules that can consume the corresponding power and the number of energy storage modules that need to be operated during the operation of the photovoltaic system according to the output power of the photovoltaic system and the power required by the electrolyzer;

[0101] The power supply control module is used to control the output voltage of the first electrolyzer power supply unit according to the output voltage loop for the electrolyzer module, and the other electrolyzer power supply units use the input voltage loop control circuit to calculate the input voltage reference value of the electrolyzer; for the energy storage module, the input voltage of the energy storage module is determined according to the output power of the photovoltaic system and the input voltage reference value of the electrolyzer, thereby controlling the charging and discharging of the energy storage module.

[0102] The device further includes a fault judgment module, which is configured to:

[0103] Obtaining the operating voltage of the electrolyzer module;

[0104] Determine whether the cell voltage fluctuation range exceeds the set fluctuation range;

[0105] If exceeded, the corresponding electrolyzer module is a bypass fault module, and the upper and lower power switch devices of the same bridge arm of the DC / DC module of the power supply circuit of the module are controlled to be turned on at the same time, bypassing the faulty electrolyzer and putting into use an electrolyzer with the same power that has been repaired, and marking the bypassed electrolyzer as waiting for maintenance;

[0106] If it is not exceeded, the corresponding electrolyzer module can be put into use.

[0107] In the operation quantity optimization module, the number of electrolyzer modules that can consume the corresponding power and the number of energy storage modules that need to be operated are calculated based on the obtained output power of the photovoltaic system and the power required by the electrolyzer, including:

[0108] Calculate the absolute value of the maximum output power difference between the current moment and the previous moment;

[0109] Determine the absolute value and the power required by the electrolytic cell:

[0110] If the absolute value is greater than the power required by the electrolyzer, determine whether the maximum output power difference between the current moment and the previous moment is greater than 0. If it is greater than 0, calculate the number of electrolyzer modules invested and the power that needs to be stored in the energy storage module based on the maximum output power difference between the current moment and the previous moment and the power required by the electrolyzer; otherwise, calculate the number of electrolyzers to be bypassed and the power that needs to be released by the energy storage module based on the absolute value and the power required by the electrolyzer;

[0111] If the absolute value is less than the power required by the electrolyzer, determine whether the maximum output power difference between the current moment and the previous moment is greater than 0. If it is greater than 0, the energy storage module needs to store the power corresponding to the maximum output power difference between the current moment and the previous moment. Otherwise, the energy storage module needs to release the power corresponding to the output power difference.

[0112] Embodiment 3

[0113] This embodiment provides a photovoltaic power generation direct-driven CO2 modular power supply system, including an electrolyzer module, an energy storage module and a photovoltaic power generation direct-driven CO2 modular power supply control device as described in the above-mentioned embodiment 2.

[0114] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A photovoltaic power generation direct-driven CO2 modular power supply control method, comprising the following steps: Estimate the number of electrolyzers and energy storage modules required for the PV system based on the rated output power of the PV system, the power required by the electrolyzer, and the capacity of the energy storage module; During the operation of the photovoltaic system, the number of electrolyzer modules that can consume the corresponding power and the number of energy storage modules that need to be operated are calculated based on the output power of the photovoltaic system and the power required by the electrolyzer, including: Calculate the absolute value of the maximum output power difference between the current moment and the previous moment; Determine the absolute value and the power required by the electrolytic cell: If the absolute value is greater than the power required by the electrolyzer, determine whether the maximum output power difference between the current moment and the previous moment is greater than 0. If it is greater than 0, calculate the number of electrolyzer modules invested and the power that needs to be stored in the energy storage module based on the maximum output power difference between the current moment and the previous moment and the power required by the electrolyzer; otherwise, calculate the number of electrolyzers to be bypassed and the power that needs to be released by the energy storage module based on the absolute value and the power required by the electrolyzer; If the absolute value is less than the power required by the electrolyzer, determine whether the maximum output power difference between the current moment and the previous moment is greater than 0. If it is greater than 0, the energy storage module needs to store the power corresponding to the maximum output power difference between the current moment and the previous moment. Otherwise, the energy storage module needs to release the power corresponding to the output power difference. For the electrolyzer module, the output voltage of the first electrolyzer power supply unit is controlled according to the output voltage loop, and the remaining electrolyzer power supply units use the input voltage loop control loop to calculate the input voltage reference value of the electrolyzer; For the energy storage module, the input voltage of the energy storage module is determined according to the output power of the photovoltaic system and the input voltage reference value of the electrolyzer, thereby controlling the charging and discharging of the energy storage module.

2. A photovoltaic power generation direct-driven CO2 modular power supply control method as claimed in claim 1, characterized in that: The calculation method for the number of electrolyzers and energy storage modules required for a photovoltaic system is: ， ， Where M is the number of electrolyzers required for the photovoltaic system. P out is the rated output power of the photovoltaic system, P work is the power required by the electrolyzer, X is the number of spare electrolyzer modules; N is the number of energy storage modules required for the photovoltaic system, P str_capa is the capacity of the energy storage module, and Y is the energy storage ratio of the new energy power station.

3. A photovoltaic power generation direct-driven CO2 modular power supply control method as claimed in claim 1, characterized in that: The control method further comprises: Obtaining the operating voltage of the electrolyzer module; Determine whether the cell voltage fluctuation range exceeds the set fluctuation range; If exceeded, the corresponding electrolyzer module is a bypass fault module, and the upper and lower power switch devices of the same bridge arm of the DC / DC module of the power supply circuit of the module are controlled to be turned on at the same time, bypassing the faulty electrolyzer and putting into use an electrolyzer with the same power that has been repaired, and marking the bypassed electrolyzer as waiting for maintenance; If it is not exceeded, the corresponding electrolyzer module can be put into use.

4. A photovoltaic power generation direct-driven CO2 modular power supply control method as claimed in claim 1, characterized in that: The calculation formula of the input voltage reference value of the electrolyzer is: ， Where s is the serial number of the electrolyzer power supply module, The input voltage of the electrolyzer power supply module, It is the input voltage reference value of the electrolyzer power supply module. is the supply voltage of the electrolyzer, is the equivalent impedance of the electrolytic cell, The input voltage of the electrolyzer power supply module with serial number 1, The equivalent impedance of the electrolyzer power supply module is number 1, The supply voltage of the electrolytic cell with serial number 1 of the electrolytic cell power supply module.

5. A photovoltaic power generation direct-driven CO2 modular power supply control method as claimed in claim 1, characterized in that: The calculation formula for the input voltage of the energy storage module is: ， in, is the serial number of the energy storage module, is the input voltage of the energy storage module.

6. A photovoltaic power generation direct-driven CO2 modular power supply control device, characterized in that: include: The system configuration module is used to estimate the number of electrolyzers and energy storage modules required for the photovoltaic system based on the rated output power of the photovoltaic system, the power required by the electrolyzer, and the capacity of the energy storage module; The operation quantity optimization module is used in the operation of the photovoltaic system. According to the output power of the photovoltaic system and the power required by the electrolyzer, the number of electrolyzer modules that can consume the corresponding power and the number of energy storage modules that need to be operated are calculated, including: Calculate the absolute value of the maximum output power difference between the current moment and the previous moment; Determine the absolute value and the power required by the electrolytic cell: If the absolute value is greater than the power required by the electrolyzer, determine whether the maximum output power difference between the current moment and the previous moment is greater than 0. If it is greater than 0, calculate the number of electrolyzer modules invested and the power that needs to be stored in the energy storage module based on the maximum output power difference between the current moment and the previous moment and the power required by the electrolyzer; otherwise, calculate the number of electrolyzers to be bypassed and the power that needs to be released by the energy storage module based on the absolute value and the power required by the electrolyzer; If the absolute value is less than the power required by the electrolyzer, determine whether the maximum output power difference between the current moment and the previous moment is greater than 0. If it is greater than 0, the energy storage module needs to store the power corresponding to the maximum output power difference between the current moment and the previous moment. Otherwise, the energy storage module needs to release the power corresponding to the output power difference. The power supply control module is used to control the output voltage of the first electrolyzer power supply unit according to the output voltage loop for the electrolyzer module, and the other electrolyzer power supply units use the input voltage loop control circuit to calculate the input voltage reference value of the electrolyzer; for the energy storage module, the input voltage of the energy storage module is determined according to the output power of the photovoltaic system and the input voltage reference value of the electrolyzer, thereby controlling the charging and discharging of the energy storage module.

7. A photovoltaic power generation direct-drive CO2 modular power supply control device as claimed in claim 6, characterized in that: The device further includes a fault judgment module, which is configured to: Obtaining the operating voltage of the electrolyzer module; Determine whether the cell voltage fluctuation range exceeds the set fluctuation range; If exceeded, the corresponding electrolyzer module is a bypass fault module, and the upper and lower power switch devices of the same bridge arm of the DC / DC module of the power supply circuit of the module are controlled to be turned on at the same time, bypassing the faulty electrolyzer and putting into use an electrolyzer with the same power that has been repaired, and marking the bypassed electrolyzer as waiting for maintenance; If it is not exceeded, the corresponding electrolyzer module can be put into use.

8. A photovoltaic power generation direct-driven CO2 modular power supply control device as claimed in claim 6, characterized in that: In the operation quantity optimization module, the number of electrolyzer modules that can consume the corresponding power and the number of energy storage modules that need to be operated are calculated based on the obtained output power of the photovoltaic system and the power required by the electrolyzer, including: Calculate the absolute value of the maximum output power difference between the current moment and the previous moment; Determine the absolute value and the power required by the electrolytic cell: If the absolute value is greater than the power required by the electrolyzer, determine whether the maximum output power difference between the current moment and the previous moment is greater than 0. If it is greater than 0, calculate the number of electrolyzer modules invested and the power that needs to be stored in the energy storage module based on the maximum output power difference between the current moment and the previous moment and the power required by the electrolyzer; otherwise, calculate the number of electrolyzers to be bypassed and the power that needs to be released by the energy storage module based on the absolute value and the power required by the electrolyzer; If the absolute value is less than the power required by the electrolyzer, determine whether the maximum output power difference between the current moment and the previous moment is greater than 0. If it is greater than 0, the energy storage module needs to store the power corresponding to the maximum output power difference between the current moment and the previous moment. Otherwise, the energy storage module needs to release the power corresponding to the output power difference.

9. A photovoltaic power generation direct-driven CO2 modular power supply system, characterized in that: It comprises an electrolyzer module, an energy storage module and a photovoltaic power generation direct-driven CO2 modular power supply control device as described in any one of claims 6 to 8.

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