Off-grid wind power and photovoltaic complementary coupling power generation and hydrogen production system

Abstract

The invention discloses an off-grid wind power and photovoltaic complementary coupling power generation and hydrogen production system, which comprises a hydrogen production power supply and an electrolytic bath connected with the hydrogen production power supply, the direct current and the alternating current of the electric energy are coupled and dynamically adjusted and converted into the current needed by the electrolytic cell according to the operation information of the electrolytic cell and the intensity change of the input electric energy, and the electric energy at least comprises photovoltaic power for outputting the direct current and / or wind power for outputting the alternating current; the electrolytic tank is used for electrolytic hydrogen production under the power supply action of the hydrogen production power supply. The hydrogen production system has the advantages of high intelligence, high stability, high reliability and the like.

Description

Technical Field

[0001] The present invention belongs to the technical field of hydrogen production by electrolysis of water, and specifically relates to an off-grid wind power and photovoltaic complementary coupling power generation and hydrogen production system. Background Art

[0002] The uneven distribution of electricity production and consumption in my country, the technical constraints of long-distance transmission, and the inherent randomness, volatility, seasonality and anti-peak characteristics of renewable energy generation have resulted in uneven distribution and unstable power generation in wind power and photovoltaic power, which has brought certain difficulties to their grid connection. At present, the wind power and photovoltaic installed capacity available for grid connection in many parts of China has reached the upper limit, resulting in serious wind, photovoltaic and water abandonment. The use of water electrolysis hydrogen production technology to recycle and utilize abandoned wind and solar power can not only effectively solve the problem of renewable energy consumption and grid connection stability in my country, but also solve the problem of carbon emissions in the metallurgical and chemical industries in the future.

[0003] Wind-solar coupling hydrogen production can form a new energy supply system that can effectively solve the drawbacks of traditional energy supply. When the capacity of the generator sets is the same, the wind-solar complementary power generation and hydrogen production system has obvious advantages over the single wind power or photovoltaic hydrogen production system. By utilizing the complementarity of wind and solar energy, wind power can be supplemented by photovoltaics when it is intermittent, and a relatively stable output current can be obtained, and the system has high stability and reliability. Taking Suzhou's climate as an example, Suzhou has weak wind and strong light during the day, and weak light and strong wind at night. By utilizing the complementary advantages of wind and solar energy, a wind-solar complementary hydrogen production power source can be designed. Therefore, the current output by wind-solar coupling is less volatile than that of pure wind power or pure photovoltaics, which can better match the working conditions of the electrolyzer, improve energy utilization efficiency, and obtain better social and economic benefits.

[0004] At present, there are three main technical difficulties in the production of green hydrogen by wind-solar coupling. First, the randomness and volatility of photovoltaic and wind power are very large. The strongest sunshine time every day is between 11 and 15 o'clock, and there is no light at night; wind power is more volatile, which means that the current and voltage output by photovoltaic and wind power fluctuate randomly. Secondly, photovoltaic outputs direct current (DC), while wind power outputs alternating current (AC). There is no mature solution in the world to design an electrolyzer hydrogen production power supply based on AC and DC coupling technology. In addition, commercially available alkaline electrolyzer systems all require a stable supply of direct current (DC). The volatility of photovoltaic and wind power will cause the hydrogen and oxygen at the anode and cathode of the electrolyzer to cross each other, damage the catalyst and diaphragm of the electrolyzer, and there is a risk of explosion. Summary of the invention

[0005] The main purpose of the present invention is to provide an off-grid wind power and photovoltaic complementary coupling power generation and hydrogen production system, thereby overcoming the deficiencies of the prior art.

[0006] In order to achieve the above-mentioned invention object, the technical solution adopted by the present invention includes: an off-grid wind power and photovoltaic complementary coupling power generation and hydrogen production system, comprising: A hydrogen production power source, used for inputting electric energy required for hydrogen production, and for coupling and dynamically adjusting the direct current and alternating current of the electric energy according to the operation information of the electrolyzer and the intensity change of the input electric energy, and converting the electric energy into the current required by the electrolyzer, wherein the electric energy at least includes photovoltaic power outputting direct current and / or wind power outputting alternating current; The electrolyzer is connected to the hydrogen production power supply and is used for producing hydrogen by electrolysis under the power supply of the hydrogen production power supply.

[0007] In a preferred embodiment, the input photovoltaic and wind power electric energy accounts for 1% to 99% each, and the energy input ratio of the wind power to the photovoltaic power is greater than 0.25 and less than 2.

[0008] In a preferred embodiment, the hydrogen production power supply includes a control module, which obtains the operating information of the electrolyzer through a communication signal, and the operating information includes polarization curve information of the electrolyzer at different temperatures; the control module also obtains the maximum output power of the photovoltaic and wind power according to the intensity of the photovoltaic and wind power, and couples the DC and AC power of the electrical energy at the maximum output power point and dynamically adjusts the conversion output to a current that matches the polarization curve of the electrolyzer.

[0009] In a preferred embodiment, the hydrogen production power supply also includes a power conversion module connected to both the control module and the electrolyzer, and the power conversion module includes at least a DC / DC converter and / or an AC / DC rectifier. The DC / DC converter and the AC / DC rectifier are respectively used to convert the direct current output of photovoltaic power and the alternating current output of wind power, and finally output direct current to the electrolyzer.

[0010] In a preferred embodiment, the DC / DC converter and the AC / DC rectifier both have a maximum output power point functional module for dynamically tracking the maximum output power point.

[0011] In a preferred embodiment, the electrolyzer operates in the range of 10% to 110% of the rated power, and the electrolyzer includes at least an alkaline electrolyzer, a proton exchange membrane electrolyzer and an anion exchange membrane electrolyzer. The control module is also used to determine the amount of electricity to be allocated to the alkaline electrolyzer, the proton exchange membrane electrolyzer and the anion exchange membrane electrolyzer respectively according to changes in the output power of photovoltaic and wind power.

[0012] In a preferred embodiment, when the output power of photovoltaic and wind power is lower than 20% of the installed capacity, the control module preferentially supplies power to the alkaline electrolyzer, and the excess power is distributed to the proton exchange membrane electrolyzer and the anion exchange membrane electrolyzer.

[0013] In a preferred embodiment, the heat exchanger of the alkaline electrolyzer is connected to the heat exchanger of the proton exchange membrane electrolyzer and / or the anion exchange membrane electrolyzer, and the electrolyzer exchanges heat with the outdoors; when the electrolyzer operates normally, the electrolyzer exchanges heat with the outdoors, and when the output power of the photovoltaic and wind power is lower than 20% of the installed capacity, the electrolyzer stops exchanging heat with the outdoors, and the alkaline electrolyzer transfers heat to the proton exchange membrane electrolyzer and / or the anion exchange membrane electrolyzer.

[0014] In a preferred embodiment, the system also includes a hydrogen storage system and an energy storage system. The hydrogen storage system is connected to the electrolyzer and is used to store hydrogen generated by electrolysis in the electrolyzer. The energy storage system is connected to the hydrogen production power supply and is used to provide electrical energy to the electrolyzer when external electrical energy cannot be input into the hydrogen production power supply.

[0015] In a preferred embodiment, the energy storage system includes a lithium battery energy storage system or a fuel cell energy storage and supply system.

[0016] Compared with the prior art, the beneficial effects of the present invention are at least: The present invention designs a hydrogen production power supply for an electrolyzer based on wind power and photovoltaic coupling complementary technology. Specifically, the electrolysis voltage and current required by the electrolyzer are determined by obtaining the operation information of the electrolyzer, such as the polarization curve information of the electrolyzer at different temperatures. Subsequently, the maximum output power of photovoltaic and wind power is obtained according to the intensity of photovoltaic and wind power. At the maximum power point, the power conversion module of photovoltaic and wind power outputs the voltage and current that can match the polarization curve of the electrolyzer, which can reduce the energy consumption of water electrolysis and greatly improve the intelligence, stability and reliability of the hydrogen production system.

[0017] The present invention can also flexibly distribute corresponding electricity to each electrolytic cell in the electrolytic cell according to the changes in photovoltaic and wind power output energy, and can fully utilize the heat by combining with a novel heat exchanger connection technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 is a schematic diagram of the overall structure of a hydrogen production system in one embodiment of the present invention; Figure 2 It is a schematic diagram of the principle of a hydrogen production power supply in one embodiment of the present invention; Figure 3It is a schematic diagram of the connection structure of multiple electrolytic cell heat exchangers in one embodiment of the present invention; Figure 4 is a schematic diagram of changes in electrolysis voltage and alkali solution temperature over time in the electrolytic cell in Example 1 of the present invention; Figure 5 Schematic diagram of the changes of hydrogen in oxygen and oxygen in hydrogen during the hydrogen production process of the electrolyzer in Example 1 of the present invention; Figure 6 Schematic diagram of changes in gas impurities in the electrolytic cell caused by adjusting the current in Example 1 of the present invention; Figure 7 Schematic diagram of the changes of hydrogen in oxygen and oxygen in hydrogen during the hydrogen production process of the electrolyzer in Example 2 of the present invention; Figure 8 is a schematic diagram of changes in impurities in electrolytic cell gas caused by adjusting the current in Example 2 of the present invention; Fig. 9 This is a schematic diagram of the energy conversion rate of the hydrogen production power supply of the present invention. DETAILED DESCRIPTION

[0020] The present invention will be more fully understood through the following detailed description, which should be read in conjunction with the accompanying drawings. Detailed embodiments of the present invention are disclosed herein; however, it should be understood that the disclosed embodiments are only exemplary of the present invention, which can be embodied in various forms. Therefore, the specific functional details disclosed herein should not be interpreted as limiting, but only as the basis of the claims and as a representative basis for teaching those skilled in the art to adopt the present invention in different ways in virtually any appropriate detailed embodiment.

[0021] like Figure 1 As shown, an off-grid wind power and photovoltaic complementary coupling power generation and hydrogen production system disclosed in an embodiment of the present invention is used to use abandoned wind and photovoltaic resources for electrolysis of water to produce hydrogen when there is surplus wind and photovoltaic resources in the regional power grid. The hydrogen production system mainly includes a hydrogen production power supply and an electrolyzer connected to the hydrogen production power supply, wherein the hydrogen production power supply is designed based on wind power and photovoltaic coupling complementary technology, and the DC and AC power of the electric energy are coupled and dynamically adjusted to be converted into the current required by the electrolyzer according to the operation information of the electrolyzer and the intensity change of the input electric energy.

[0022] Specifically, the electric energy input by the hydrogen production power supply can be supplied by photovoltaic, wind power, power grid, battery, etc. In this embodiment, photovoltaic and / or wind power are preferentially input. Among them, the proportion of photovoltaic electric energy input to the hydrogen production power supply is 1%~99%, and the proportion of wind power electric energy input to the hydrogen production power supply is also 1%~99%, and the energy input ratio of wind power to photovoltaic is greater than 0.25 and less than 2. When the energy input ratio of wind power to photovoltaic is greater than 0.25, that is, when there is no light at night, relying on wind power, the electrolyzer can be maintained at about 20% of the rated power to avoid repeated startup and shutdown; the energy input ratio of wind power to photovoltaic also needs to be less than 2. When encountering extreme conditions during the day and the wind stops completely, the electrolyzer can be maintained at about 20% of the rated power by relying on light.

[0023] In this embodiment, combined with Figure 2 As shown, the hydrogen production power supply mainly includes a power conversion module and a control module, wherein the power conversion module is connected to the control module and the electrolyzer, and includes at least a DC / DC converter and / or an AC / DC rectifier. The DC / DC converter is used to convert the DC power output of the photovoltaic power plant into DC power, and the AC / DC rectifier is used to convert the AC power output of the wind power plant into DC power. The final stable DC power is input to the electrolyzer. Preferably, the AC / DC rectifier adopts a silicon carbide (SiC) new semiconductor material power converter product or an IGBT module hydrogen production power product or a thyristor module hydrogen production power product. And both the DC / DC converter and the AC / DC rectifier have a maximum output power point (MPPT) function module that dynamically tracks the maximum output power point.

[0024] The control module is connected to the electrolyzer in communication, and is used to obtain the operation information of the electrolyzer through the communication signal, and the operation information includes the polarization curve information of the electrolyzer at different temperatures, and determines the electrolysis voltage and current required by the electrolyzer; the control module also includes obtaining the maximum output power of photovoltaic and wind power by using the above-mentioned MPPT function module according to the intensity of photovoltaic and wind power, and coupling and dynamically adjusting the DC and AC of the electric energy at the maximum output power point through the above-mentioned photovoltaic DC / DC converter and the wind power AC / DC rectifier to convert and output the current and voltage that match the polarization curve of the electrolyzer. That is, the control module can adjust the output voltage and current at any time according to the operating status of the electrolyzer and the changes in the intensity of photovoltaic and wind power. In addition, the control module is also connected to the cloud management platform in communication, and can save multiple photovoltaic, wind and electrolyzer operation data, and quickly match the output size of current and voltage according to the historical wind and photovoltaic intensity data.

[0025] In this embodiment, the electrolyzer connected to the hydrogen production power source has a wide load power range, specifically, it can operate in the range of 10% to 110% of the rated power. Preferably, the current power that can be output by the total installed capacity of photovoltaic and wind power is 10% higher than the installed rated power of the electrolyzer. When the wind and photovoltaic power are good, the electrolyzer can operate at 100% of the rated power. The excess 10% of electricity generated by photovoltaic and wind power can be used to charge the energy storage battery or directly increase the load power of the electrolyzer to 110%.

[0026] In this embodiment, the electrolyzer includes at least an alkaline (ALK) electrolyzer, a proton exchange membrane (PEM) electrolyzer, and an anion exchange membrane (AEM) electrolyzer. The control module is also used to determine the amount of electricity to be allocated to the alkaline electrolyzer, the proton exchange membrane electrolyzer, and the anion exchange membrane electrolyzer according to the change in the output power of photovoltaic and wind power. The specific implementation method is that when the output power of photovoltaic and wind power is less than 20% of the installed capacity, the control module gives priority to powering the ALK electrolyzer to maintain 20% of the rated operating power, and the surplus power is allocated to the PEM electrolyzer and the AEM electrolyzer.

[0027] In addition, due to the differences in the operating temperature and startup speed of the above three types of electrolyzers, specifically, the operating temperature of the ALK electrolyzer is about 85°C, while that of the PEM electrolyzer and AEM electrolyzer is 60°C. In the installation process of large-scale wind and light complementary hydrogen production electrolyzers, ALK, PEM and AEM electrolyzers can choose 2 or 3 types for installation. The heat exchange functional components of these electrolyzers are different from the heat exchangers of commercially available electrolyzers. Common electrolyzer heat exchangers use water cooling to quickly remove the heat generated by the electrolyzer to the outdoors.

[0028] Based on the above differences, the present invention combines and connects the heat exchangers of the three electrolytic cells. Figure 3As shown in the figure, since the operating temperature of PEM and AEM electrolyzers is relatively low, the heat exchangers of these two electrolyzers are connected to the heat exchanger of ALK electrolyzers during the design and assembly of the electrolyzers, and the heat exchange system retains the function of heat exchange with the outside. When the electrolyzers are operating at rated power, ALK, PEM and AEM electrolyzers maintain the function of heat exchange with the outside and maintain their respective rated operating temperatures. When the energy output of photovoltaic and wind power is insufficient, since the operation of ALK electrolyzers at lower power (<20% rated power) will cause serious crosstalk between hydrogen and oxygen, the alkaline electrolyzers are powered first, and the surplus power is then supplied to PEM or AEM electrolyzers. At this time, the function of heat exchange between ALK, PEM and AEM electrolyzers and the outside is stopped. Since the heat exchanger of the ALK electrolyzer is connected to the heat exchanger of the AEM electrolyzer or the PEM electrolyzer, the ALK electrolyzer operates at a higher temperature, so the heat of the alkali solution can be transferred to the AEM and PEM electrolyzers, allowing them to maintain the rated operating temperature and operate at 5~10% of the rated power.

[0029] In addition, the present invention also includes a hydrogen storage system and an energy storage system, wherein the hydrogen storage system is connected to the electrolyzer to store hydrogen generated by electrolysis in the electrolyzer, and the energy storage system is connected to the hydrogen production power supply to provide power to the electrolyzer system in extreme cases, such as when wind power and photovoltaic power cannot input power, so that the electrolyzer does not need to be shut down and maintains operation at a lower rated load (about 20% rated load power). In this embodiment, the energy storage system includes a lithium battery energy storage system or a fuel cell energy storage and energy supply system.

[0030] Several embodiments are used below to illustrate the performance of the off-grid wind power and photovoltaic complementary coupling power generation and hydrogen production system of the present invention.

[0031] Example 1 When the rated voltage of the electrolyzer of the hydrogen production system is 200V and the rated current is 456A, wind power and photovoltaic power input AC and DC power for hydrogen production. The hydrogen production power supply converts these renewable power sources into DC power with a voltage of 200V, and dynamically adjusts the voltage and current according to the polarization curve of the electrolyzer and the changes in the intensity of light and wind. When the electrolyzer is just started, the alkali solution temperature is close to room temperature. At this time, the hydrogen production power supply can match the polarization curve of the electrolyzer, and the voltage can quickly reach 200V. As the temperature of the alkali solution increases, the activity of the water electrolysis reaction also increases, and the electrolysis voltage required by the electrolyzer also decreases (such as Figure 4As shown). When the alkali solution temperature rises from room temperature to 70°C, the corresponding electrolyzer input voltage can be reduced from 200V to 187V, which means that the DC energy consumption of water electrolysis is also reduced. This shows that the off-grid wind power and photovoltaic complementary coupling power generation and hydrogen production system of the present invention can match the current-voltage curve (IV curve) of the water electrolysis process, dynamically adjust the value of the electrolysis voltage according to the reaction activity of water electrolysis, and reduce the energy consumption of water electrolysis, which fully reflects that the wind power and photovoltaic complementary coupling power generation and hydrogen production system of the present invention has high intelligence.

[0032] Moreover, under normal sunshine and wind conditions, the hydrogen production power supply of the present invention can output a relatively stable current with little current fluctuation, so the concentration of impurity gas (i.e. hydrogen in oxygen, oxygen in hydrogen) generated by the anode and cathode can be stably maintained at a low value. Figure 5 As shown, the concentration of hydrogen in oxygen fluctuates between 0.5% and 0.6%, which is far below the lower limit of 2% that causes the electrolyzer to automatically shut down, and the purity of hydrogen is stable at more than 99.9%, indicating that the off-grid wind power and photovoltaic complementary coupling power generation and hydrogen production system of the present invention is very stable.

[0033] When the electrolyzer is operated at low power, the concentration of impurity gas (i.e. hydrogen in oxygen, oxygen in hydrogen) generated at the anode and cathode will be too high. Especially when the electrolyzer is operated at a power level reduced from 100% to 20% in a very short time, the impurity concentration of the gas on both sides of the anode and cathode of the electrolyzer will increase rapidly. Figure 6 As shown in the figure, when the output current of the hydrogen production power supply is artificially reduced from 435A to 96A, the concentration of gas impurities (hydrogen in oxygen, oxygen in hydrogen) produced by the electrolyzer will also increase, and the concentration of hydrogen in oxygen will be close to 1%, while the purity of cathode hydrogen can be maintained at more than 99.5%, indicating that the wind power and photovoltaic complementary coupling power generation hydrogen production system of the present invention has high reliability. Figure 6 It can also be seen that the system can withstand frequent large fluctuations in current in the short term, and the hydrogen and oxygen impurities in the electrolyzer do not exceed the design standards during the process.

[0034] Example 2 When the rated voltage of the electrolyzer of the hydrogen production system is 200V and the rated current is 456A. ​​Under normal sunshine and wind conditions, the hydrogen production power supply system of the present invention can output a relatively stable voltage, so the concentration of impurity gas (i.e., hydrogen in oxygen, oxygen in hydrogen) generated by the anode and cathode can be stably maintained at a low value. Figure 7 As shown, the concentration of hydrogen in oxygen fluctuates between 0.5% and 0.6%, which is far below the lower limit of 2% that causes the electrolyzer to automatically shut down, and the purity of hydrogen is stable at more than 99.9%, indicating that the off-grid photovoltaic wind power water electrolysis hydrogen production system of the present invention is very stable.

[0035] When the electrolyzer is operated at low power, the concentration of impurity gas (i.e. hydrogen in oxygen, oxygen in hydrogen) generated at the anode and cathode will be too high. Especially when the electrolyzer is operated at a power level reduced from 100% to 20% in a very short time, the impurity concentration of the gas on both sides of the anode and cathode of the electrolyzer will increase rapidly. Figure 8 As shown, this is the case of the electrolyzer system under non-continuous fluctuating current. When the output current of the hydrogen production power supply is artificially reduced from 435A to 96A, the concentration of gas impurities (hydrogen in oxygen, oxygen in hydrogen) produced by the electrolyzer will also increase. The concentration of hydrogen in oxygen will exceed 1%, but is lower than the upper limit of the electrolyzer shutdown alarm of 2%, indicating that the hydrogen production system of the present invention has high reliability.

[0036] Example 3 When the photovoltaic and wind power output energy is low (about 20% of the rated installed capacity), the present invention can make full use of the heat by combining and connecting the heat exchangers of the electrolyzers. For example, at 20% of the total installed capacity of photovoltaic and wind power (because the total installed power of wind and solar power is 10% higher than the total power of the electrolyzer), the ALK, PEM and AEM electrolyzers can only reach 22% of the rated power. By using the technology of combining and connecting the heat exchangers of the electrolyzers in the present invention, the ALK electrolyzer operates at 30% of the rated power, and the PEM and AEM electrolyzers operate at 10% of the rated power respectively. The heat generated by the ALK is transferred to the reaction liquid of the PEM and AEM electrolyzers through the heat exchanger connection technology. As shown in the table below, after avoiding heat waste through the present invention, the reaction liquid temperature of each electrolyzer is 10°C higher.

[0037] Table 3 Comparison of rated temperatures of three electrolytic cells

[0038] In addition, if Fig. 9 As shown in FIG. 1 , it is a schematic diagram of the efficiency of the hydrogen production power supply of the present invention. The hydrogen production power supply of the present invention is composed of multiple AC / DC rectifiers and DC / DC converters. According to the topological structure analysis of the power module, the efficiency of the hydrogen production power supply is determined by the MPPT efficiency, AC / DC and DC / DC conversion rates, as shown in FIG. Fig. 9 As shown, the energy conversion efficiency of a single power module is above 97%, with the highest reaching 97.8%, indicating that 97.8% of renewable energy can be used to convert into direct current (DC) required by the electrolyzer. If a grid-connected water electrolysis system is used, photovoltaic and wind power must first be converted into alternating current (AC) through DC / AC and AC / AC and then connected to the grid. Then, the AC / DC module converts the grid AC into direct current (DC) to power the electrolyzer. Renewable electricity needs to be converted twice. The efficiencies of commonly used DC / AC inverters and AC / DC rectifiers are 97.3% and 95.1%, respectively. Therefore, the comprehensive energy conversion rate is 92.5%, namely: ; Compared with the energy conversion rate of 97% in the solution of the present invention, it is nearly 5% lower.

[0039] A hydrogen production system provided by an embodiment of the present invention has the following advantages: 1. The present invention designs the hydrogen production power supply of the electrolyzer based on the wind power and photovoltaic coupling complementary technology, and specifically determines the electrolysis voltage and current required by the electrolyzer by obtaining the operation information of the electrolyzer, such as the polarization curve information of the electrolyzer at different temperatures. Subsequently, according to the intensity of photovoltaic and wind power, the maximum output power of photovoltaic and wind power is obtained, and at the maximum power point, the power conversion module of photovoltaic and wind power outputs the voltage and current that can match the polarization curve of the electrolyzer, which can reduce the energy consumption of water electrolysis and greatly improve the intelligence, stability and reliability of the hydrogen production system. 2. The present invention can also flexibly allocate corresponding electricity to each electrolyzer in the electrolyzer according to the changes in photovoltaic and wind power output energy, and combined with the new heat exchanger connection technology, the heat can be fully utilized.

[0040] The various aspects, embodiments, features and examples of the present invention should be considered as illustrative in all aspects and are not intended to limit the present invention, the scope of the present invention is defined only by the claims. Other embodiments, modifications and uses will be apparent to those skilled in the art without departing from the spirit and scope of the claimed invention.

[0041] The use of headings and sections in this disclosure is not meant to limit the disclosure; each section may apply to any aspect, embodiment, or feature of the disclosure.

Claims

1. An off-grid wind power and photovoltaic complementary coupling power generation and hydrogen production system, characterized by: The system comprises: A hydrogen production power source, used for inputting electric energy required for hydrogen production, and for coupling and dynamically adjusting the direct current and alternating current of the electric energy according to the operation information of the electrolyzer and the intensity change of the input electric energy, and converting the electric energy into the current required by the electrolyzer, wherein the electric energy at least includes photovoltaic power outputting direct current and / or wind power outputting alternating current; The electrolyzer is connected to the hydrogen production power supply and is used for producing hydrogen by electrolysis under the power supply of the hydrogen production power supply.

2. The off-grid wind power and photovoltaic complementary coupling power generation and hydrogen production system according to claim 1, characterized in that: The input photovoltaic and wind power electric energy accounts for 1% to 99% each, and the energy input ratio of wind power to photovoltaic power is greater than 0.25 and less than 2.

3. The off-grid wind power and photovoltaic complementary coupling power generation and hydrogen production system according to claim 1, characterized in that: The hydrogen production power supply includes a control module, which obtains the operating information of the electrolyzer through a communication signal, and the operating information includes polarization curve information of the electrolyzer at different temperatures; the control module also obtains the maximum output power of the photovoltaic and wind power according to the intensity of the photovoltaic and wind power, and couples the direct current and alternating current of the electrical energy at the maximum output power point and dynamically adjusts and converts the output into a current that matches the polarization curve of the electrolyzer.

4. The off-grid wind power and photovoltaic complementary coupling power generation and hydrogen production system according to claim 3 is characterized by: The hydrogen production power supply also includes a power conversion module connected to both the control module and the electrolyzer, and the power conversion module includes at least a DC / DC converter and / or an AC / DC rectifier. The DC / DC converter and the AC / DC rectifier are respectively used to convert the direct current output of photovoltaic power and the alternating current output of wind power into power, and finally output direct current to the electrolyzer.

5. The off-grid wind power and photovoltaic complementary coupling power generation and hydrogen production system according to claim 4 is characterized by: The DC / DC converter and the AC / DC rectifier both have a maximum output power point functional module for dynamically tracking the maximum output power point.

6. The off-grid wind power and photovoltaic complementary coupling power generation and hydrogen production system according to claim 3 is characterized by: The electrolyzer operates in the range of 10% to 110% of the rated power, and the electrolyzer includes at least an alkaline electrolyzer, a proton exchange membrane electrolyzer and an anion exchange membrane electrolyzer. The control module is also used to determine the amount of electricity to be allocated to the alkaline electrolyzer, the proton exchange membrane electrolyzer and the anion exchange membrane electrolyzer respectively according to the changes in the output electricity of photovoltaic and wind power.

7. The off-grid wind power and photovoltaic complementary coupling power generation and hydrogen production system according to claim 6, characterized in that: When the output power of photovoltaic and wind power is lower than 20% of the installed capacity, the control module gives priority to supplying power to the alkaline electrolyzer, and the excess power is distributed to the proton exchange membrane electrolyzer and the anion exchange membrane electrolyzer.

8. The off-grid wind power and photovoltaic complementary coupling power generation and hydrogen production system according to claim 6, characterized in that: The heat exchanger of the alkaline electrolyzer is connected to the heat exchanger of the proton exchange membrane electrolyzer and / or the anion exchange membrane electrolyzer, and the electrolyzer exchanges heat with the outside; when the electrolyzer operates normally, the electrolyzer exchanges heat with the outside, and when the output power of the photovoltaic and wind power is lower than 20% of the installed capacity, the electrolyzer stops exchanging heat with the outside, and the alkaline electrolyzer transfers heat to the proton exchange membrane electrolyzer and / or the anion exchange membrane electrolyzer.

9. The off-grid wind power and photovoltaic complementary coupling power generation and hydrogen production system according to claim 1, characterized in that: The system also includes a hydrogen storage system and an energy storage system. The hydrogen storage system is connected to the electrolyzer and is used to store hydrogen generated by electrolysis in the electrolyzer. The energy storage system is connected to the hydrogen production power supply and is used to provide electrical energy to the electrolyzer when external electrical energy cannot be input into the hydrogen production power supply.

10. The off-grid wind power and photovoltaic complementary coupling power generation and hydrogen production system according to claim 9, characterized in that: The energy storage system includes a lithium battery energy storage system or a fuel cell energy storage and supply system.

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