A current source system for green hydrogen production and a current source control method

Abstract

This invention provides a current source system and current source control method for green hydrogen production, including a new energy AC power generation system, a new energy DC power generation system, an AC current source converter, a DC current source converter, a three-phase transformer, a single-phase transformer, and an impedance-controlled and stabilizing load. The impedance-controlled and stabilizing load includes a controlled-adjustable variable impedance device and an electrolyzer. The new energy AC power generation system is connected to the AC power source converter via the three-phase transformer. The new energy DC power generation system is connected to the DC current source converter via the single-phase transformer. The impedance-controlled and stabilizing load is connected to both the AC and DC current source converters. The three-phase and single-phase transformers achieve voltage level transformation between the power generation system and the current source converter to meet the control of the current and power of the electrolyzer in the impedance-controlled and stabilizing load. This invention can achieve reliability and safety in hydrogen production from renewable energy sources at the refinery level.

Description

Technical Field

[0001] This invention relates to the technical field of hydrogen production from new energy power generation, and particularly to a current source system and current source control method for green hydrogen production. Background Technology

[0002] Hydrogen production via water electrolysis using electricity generated from new energy sources is a major future source of green hydrogen and is currently receiving attention from various countries. Especially for refineries, achieving large-scale green and stable hydrogen supply will be a crucial factor affecting carbon neutrality in the future. Currently, large-scale hydrogen production technology using water electrolysis generated from new energy sources is still in the technology development and verification stage.

[0003] The key to large-scale hydrogen production via water electrolysis using renewable energy sources is achieving a stable direct current supply. The most crucial element in this is various AC / DC power converters. Conventional technologies typically rely on voltage sources to provide stable power, while direct current supply is more efficient. Currently, there is no clear technical route or method for achieving a stable current supply using renewable energy sources such as wind and solar power, and power supply security issues persist during water electrolysis. Summary of the Invention

[0004] To address the problems in the prior art, embodiments of the present invention provide a current source system and a current source control method for green hydrogen preparation.

[0005] Specifically, the embodiments of the present invention provide the following technical solutions:

[0006] In a first aspect, embodiments of the present invention provide a current source system for green hydrogen preparation, comprising:

[0007] New energy AC power generation system, new energy DC power generation system, AC current source converter, DC current source converter, three-phase transformer, single-phase transformer and impedance controllable and stable load, wherein the impedance controllable and stable load includes a controlled adjustable variable impedance device and an electrolytic cell;

[0008] Among them, the new energy AC power generation system is connected to the AC current source converter through a three-phase transformer; the new energy DC power generation system is connected to the DC current source converter through a single-phase transformer; the impedance-controlled and stable load is connected to the AC current source converter and the DC current source converter; the three-phase transformer and the single-phase transformer realize the voltage level transformation between the power generation system and the current source converter to meet the control of the current and power of the electrolytic cell in the impedance-controlled and stable load;

[0009] Among them, the voltage level transformation between the power generation system and the current source converter by three-phase transformers and single-phase transformers refers to the voltage level transformation between the new energy AC power generation system or the new energy DC power generation system and the AC current source converter or the DC current source converter by three-phase transformers and single-phase transformers.

[0010] Secondly, embodiments of the present invention also provide a current source control method based on the current source system for green hydrogen preparation as described above, comprising:

[0011] The power source for green hydrogen production comes from the aforementioned new energy AC power generation system or the aforementioned new energy DC power generation system; the AC current source converter acts as the controller for these new energy AC power generation systems, such as AC wind turbines and photovoltaic power generation systems; the DC current source converter acts as the controller for these new energy DC power generation systems, such as DC wind turbines and photovoltaic power generation systems, respectively realizing the conversion of wind power or photovoltaic new energy power generation; the AC current source converter adopts dual closed-loop direct current control, and the DC current source converter adopts dual closed-loop direct current control; three-phase and single-phase transformers are used for voltage level conversion; the controlled adjustable variable impedance device serves as an accessory to balance the impedance of the electrolyzer, thereby improving the current control capability, and also exists as an energy leakage bypass in the event of a DC bus fault, enhancing the safety of the electrolyzer.

[0012] Furthermore, i dc1 i dc2 , Optimized scheduling is achieved based on the current allocation optimization mechanism;

[0013] The current distribution optimization mechanism includes:

[0014] S1. Based on the dual-closed-loop AC control strategy of the new energy AC power generation system, the dual-closed-loop DC control strategy of the new energy DC power generation system, and the dynamic adjustment of the controlled adjustable variable impedance device, the system is guaranteed to function. Stablize;

[0015] S2, when i dc1 +i dc2 Output capability greater than When required, adjustments are needed at this time. To ensure Stablize;

[0016] S3, when i dc1 +i dc2 Output capability less than When required, adjustments are needed at this time. It is zero, that is, S Z open circuit;

[0017] S4. When i dc1i dc2 When the fluctuation in the control exceeds the first preset threshold, the impedance value of the controlled variable impedance is dynamically adjusted, thereby changing the electrolytic cell current.

[0018] S5. When the fluctuation of the DC bus current exceeds the second preset threshold, immediately S p The circuit is opened to protect the electrolytic cell, while the controlled variable impedance device is quickly adjusted to discharge mode to consume transient energy.

[0019] Furthermore, The stability is controlled by the new energy AC power generation system. dc1 i and new energy DC power generation system control dc2 And the adjustment control of the controlled variable impedance device The dynamic adjustment of three currents ensures that, namely:

[0020]

[0021] In the formula, It is the current i during the operation of the electrolytic cell. dc1 It is a direct current controlled by a new energy AC power generation system, i dc2 It is a DC current controlled by a new energy DC power generation system. It is a controlled adjustment of the variable impedance device.

[0022] Furthermore, the logical order of dynamic adjustment is as follows:

[0023] The power generation side is given the highest priority: when i dc1 and i dc2 When both exist, the power source with the larger generating capacity is considered the main power source, and its regulation priority is the highest; when i dc1 or i dc2 When existing independently, any one of the power sources is considered as the main power source;

[0024] Load regulation side is the second priority: after the first priority generation side current stabilization control adjustment, Adjusted as the second priority;

[0025] The current is adjusted in stages to avoid instability caused by frequent system adjustments.

[0026] Furthermore, when the fluctuation of the DC bus current exceeds the second preset threshold, it is necessary to calculate S. p First, clear the way, S Z By maintaining the connection, transient energy will be absorbed by a controlled adjustable variable impedance device, preventing further system degradation and ensuring equipment safety.

[0027] Furthermore, new energy AC power generation systems or new energy DC power generation systems can connect to and disconnect different forms of new energy power generation according to system requirements.

[0028] Furthermore, when the new energy power generation system malfunctions, the energy storage inductor L... dc1 L dc2 or L dc3 L dc4 Its energy storage function ensures the safe disconnection of the electrolytic cell while disconnecting faulty AC current source converters and DC current source converters, thereby improving the safety of the electrolytic cell system.

[0029] As can be seen from the above technical solution, the current source system and current source control method for green hydrogen production provided in this embodiment of the invention include a new energy AC power generation system, a new energy DC power generation system, an AC current source converter, a DC current source converter, a three-phase transformer, a single-phase transformer, and an impedance-controlled and stabilizing load. The impedance-controlled and stabilizing load includes a controlled adjustable variable impedance device and an electrolyzer. The new energy AC power generation system is connected to the AC current source converter through the three-phase transformer; the new energy DC power generation system is connected to the DC current source converter through the single-phase transformer; the impedance-controlled and stabilizing load is connected to both the AC and DC current source converters; the three-phase transformer and the single-phase transformer realize voltage level transformation between the power generation system and the current source converter to meet the control of the current and power of the electrolyzer in the impedance-controlled and stabilizing load. This embodiment of the invention can achieve the reliability and safety of hydrogen production from renewable energy at the refinery level. The power source for green hydrogen production comes from either an AC or DC power generation system of new energy sources. AC current source converters act as controllers for AC wind turbines, photovoltaic power generation systems, and other new energy AC power generation systems. DC current source converters act as controllers for DC wind turbines, photovoltaic power generation systems, and other new energy DC power generation systems, respectively converting power from wind power or photovoltaic power. Both AC and DC current source converters employ dual closed-loop direct current control. Three-phase and single-phase transformers are used for voltage level conversion. Controlled adjustable variable impedance devices serve as accessories to balance the impedance of the electrolyzer, improving current control capability and acting as a bypass for energy leakage in the event of a DC bus fault, thus enhancing the safety of the electrolyzer. dc1 i dc2 , Optimal scheduling is achieved based on a current allocation optimization mechanism, which is as follows: S1 ensures optimal scheduling by dynamically adjusting three aspects: the dual-closed-loop AC control strategy of the new energy AC power generation system, the dual-closed-loop DC control strategy of the new energy DC power generation system, and the adjustment of the controlled adjustable variable impedance device. Stable; S2 when i dc1 +idc2 Output capability greater than When required, adjustments are needed at this time. To ensure Stable; S3 when i dc1 +i dc2 Output capability less than When required, adjustments are needed at this time. It is zero, that is, S Z Open path; S4 when i dc1 i dc2 When the fluctuation in the control exceeds the first preset threshold, the impedance value of the controlled variable impedance is dynamically adjusted, thereby changing the electrolytic cell current. S5 When the fluctuation of the DC bus current exceeds the second preset threshold, immediately S p An open circuit is used to protect the electrolyzer's safety, while a controlled variable impedance device quickly adjusts to a discharge mode to dissipate transient energy. This invention allows for the connection and disconnection of different renewable energy generation methods according to system requirements, providing multiple safeguards for stable and safe power supply to the electrolyzer, obtaining a power source for green hydrogen production, and improving the accuracy of electrolyzer current control. The control method provided in this invention can be extended to other similar applications beyond refineries. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0031] Figure 1 This is a schematic diagram of the system topology provided in an embodiment of the present invention;

[0032] Figure 2 This is a control block diagram of an AC current source converter provided in an embodiment of the present invention;

[0033] Figure 3 This is a control block diagram of a DC current source converter provided in an embodiment of the present invention;

[0034] Figure 4 This is a control block diagram of a controlled adjustable variable impedance device;

[0035] Figure 5 This is a flowchart of the current distribution mechanism provided in an embodiment of the present invention. Detailed Implementation

[0036] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0037] To address the shortcomings of existing technologies, this invention provides a current source system and current source control method for green hydrogen production. This method is applied to large-scale scenarios of hydrogen production by electrolyzing water using electricity generated from new energy sources, meeting the reliability and safety requirements for producing refinery-grade hydrogen.

[0038] Figure 1 A schematic diagram of the topology of a current source system for green hydrogen production provided in an embodiment of the present invention is shown. Figure 1 As shown, the current source system for green hydrogen preparation provided in this embodiment of the invention includes:

[0039] New energy AC power generation system, new energy DC power generation system, AC current source converter, DC current source converter, three-phase transformer, single-phase transformer and impedance controllable and stable load, wherein the impedance controllable and stable load includes a controlled adjustable variable impedance device and an electrolytic cell;

[0040] Among them, the new energy AC power generation system is connected to the AC current source converter through a three-phase transformer; the new energy DC power generation system is connected to the DC current source converter through a single-phase transformer; the impedance-controlled and stable load is connected to the AC current source converter and the DC current source converter; the three-phase transformer and the single-phase transformer realize the voltage level transformation between the power generation system and the current source converter to meet the control of the current and power of the electrolytic cell in the impedance-controlled and stable load;

[0041] Among them, the voltage level transformation between the power generation system and the current source converter by three-phase transformers and single-phase transformers refers to the voltage level transformation between the new energy AC power generation system or the new energy DC power generation system and the AC current source converter or the DC current source converter by three-phase transformers and single-phase transformers.

[0042] like Figure 1The diagram illustrates the connection methods for each unit. The new energy AC power generation system is connected to the AC current source converter via a three-phase transformer; the new energy DC power generation system is connected to the DC current source converter via a single-phase transformer; the impedance-controlled stable load is connected to both the AC and DC current source converters; the three-phase and single-phase transformers enable voltage level transformation between the power generation system and the current source converter, thereby satisfying the current / power control of the electrolyzer in the impedance-controlled stable load. This invention allows for the connection and disconnection of different new energy power generation forms according to system requirements, achieving multiple guarantees for stable and safe power supply to the electrolyzer, obtaining a power source path for green hydrogen production, and improving the current control accuracy of the electrolyzer. This embodiment of the invention can achieve the reliability and safety of hydrogen production from new energy power generation at the refinery level.

[0043] Figure 2 This is a control block diagram of an AC current source converter provided in an embodiment of the present invention. Figure 3 This is a control block diagram of a DC current source converter provided in an embodiment of the present invention, specifically for the attached... Figure 2 , 3 This describes a scenario of the embodiment and the connection control method of each unit component. Wherein, As the ultimate goal of system control, the control objective of both AC current source converters and DC current source converters is... Stablize. Figure 4 This is a control block diagram for a controlled adjustable variable impedance device, specifically for... Figure 4 This section describes a scenario and the connection control method for each unit component in an embodiment. Closed-loop control is used to achieve this. Stability. Figure 5 This is a flowchart of the current distribution mechanism provided in an embodiment of the present invention. The following is in conjunction with... Figures 2-5 The current source control method provided in the embodiments of the present invention will be explained and described in detail.

[0044] Another embodiment of the present invention provides a current source control method for a current source system for green hydrogen preparation based on the above embodiments. The current source control method includes:

[0045] The power source for green hydrogen production comes from the aforementioned new energy AC power generation system or the aforementioned new energy DC power generation system; the AC current source converter acts as the controller for these new energy AC power generation systems, such as AC wind turbines and photovoltaic power generation systems; the DC current source converter acts as the controller for these new energy DC power generation systems, such as DC wind turbines and photovoltaic power generation systems, respectively realizing the conversion of wind power or photovoltaic new energy power generation; the AC current source converter adopts dual closed-loop direct current control, and the DC current source converter adopts dual closed-loop direct current control; three-phase and single-phase transformers are used for voltage level conversion; the controlled adjustable variable impedance device serves as an accessory to balance the impedance of the electrolyzer, thereby improving the current control capability, and also exists as an energy leakage bypass in the event of a DC bus fault, enhancing the safety of the electrolyzer.

[0046] It is understood that, based on the content of the above embodiments, in this embodiment, i dc1 i dc2 , Optimized scheduling is achieved based on the current allocation optimization mechanism;

[0047] The current distribution optimization mechanism includes:

[0048] S1. Based on the dual-closed-loop AC control strategy of the new energy AC power generation system, the dual-closed-loop DC control strategy of the new energy DC power generation system, and the dynamic adjustment of the controlled adjustable variable impedance device, the system is guaranteed to function. Stablize;

[0049] S2, when i dc1 +i dc2 Output capability greater than When required, adjustments are needed at this time. To ensure Stablize;

[0050] S3, when i dc1 +i dc2 Output capability less than When required, adjustments are needed at this time. It is zero, that is, S Z open circuit;

[0051] S4. When i dc1 i dc2 When the fluctuation in the control exceeds the first preset threshold, the impedance value of the controlled variable impedance is dynamically adjusted, thereby changing the electrolytic cell current.

[0052] S5. When the fluctuation of the DC bus current exceeds the second preset threshold, immediately S p The circuit is opened to protect the electrolytic cell, while the controlled variable impedance device is quickly adjusted to discharge mode to consume transient energy.

[0053] Understandable, The stability is controlled by the new energy AC power generation system. dc1 i and new energy DC power generation system control dc2 And the adjustment control of the controlled variable impedance device The dynamic adjustment of three currents ensures that, namely:

[0054]

[0055] In the formula, It is the current i during the operation of the electrolytic cell. dc1 It is a direct current controlled by a new energy AC power generation system, i dc2 It is a DC current controlled by a new energy DC power generation system. It is a controlled adjustment of the variable impedance device.

[0056] It is understood that, based on the content of the above embodiments, the dynamically adjusted logical order in this embodiment can be:

[0057] The power generation side is given the highest priority: when i dc1 and i dc2 When both exist, the power source with the larger generating capacity is considered the main power source, and its regulation priority is the highest; when i dc1 or i dc2 When existing independently, any one of the power sources is considered as the main power source;

[0058] Load regulation side is the second priority: after the first priority generation side current stabilization control adjustment, Adjusted as the second priority;

[0059] The current is adjusted in stages to avoid instability caused by frequent system adjustments.

[0060] It is understood that, based on the above embodiments, in this embodiment, when the fluctuation of the DC bus current exceeds the second preset threshold, it is necessary to calculate S. p First, clear the way, S Z By maintaining the connection, transient energy will be absorbed by a controlled adjustable variable impedance device, preventing further system degradation and ensuring equipment safety.

[0061] It is understood that, based on the content of the above embodiments, in this embodiment, the new energy AC power generation system or the new energy DC power generation system realizes the access and disconnection of different new energy power generation forms according to system requirements.

[0062] It is understood that, based on the content of the above embodiments, in this embodiment, when the new energy power generation system fails, the energy storage inductor L... dc1 L dc2 or L dc3 L dc4 Its energy storage function ensures the safe disconnection of the electrolytic cell while disconnecting faulty AC current source converters and DC current source converters, thereby improving the safety of the electrolytic cell system.

[0063] Therefore, the current source control method for the current source system for green hydrogen production provided in this embodiment includes: the power source for green hydrogen production comes from an AC or DC power generation system of new energy power generation; an AC current source converter acts as a controller for AC wind turbines, photovoltaic power generation systems, and other new energy AC power generation systems; a DC current source converter acts as a controller for DC wind turbines, photovoltaic power generation systems, and other new energy DC power generation systems, respectively realizing the conversion of wind power or photovoltaic power generation; the AC current source converter adopts dual closed-loop direct current control, and the DC current source converter adopts dual closed-loop direct current control; three-phase and single-phase transformers are used for voltage level conversion; a controlled adjustable variable impedance device serves as an accessory to balance the impedance of the electrolyzer, which can improve the current control capability and, in the event of a DC bus fault, acts as an energy leakage bypass, thereby improving the safety of the electrolyzer.

[0064] i dc1 i dc2 , Optimal scheduling is achieved based on a current allocation optimization mechanism. The current allocation optimization mechanism is as follows: S1 ensures optimal scheduling through dynamic adjustments based on three aspects: the dual-closed-loop AC control strategy of the new energy AC power generation system, the dual-closed-loop DC control strategy of the new energy DC power generation system, and the adjustment of the controlled adjustable variable impedance device. Stable; S2 when i dc1 +i dc2 Output capability greater than When required, adjustments are needed at this time. To ensure Stable; S3 when i dc1 +i dc2 Output capability less than When required, adjustments are needed at this time. It is zero, that is, S Z Open path; S4 when i dc1 i dc2 When the fluctuation in the control exceeds the first preset threshold, the impedance value of the controlled variable impedance is dynamically adjusted, thereby changing the electrolytic cell current. S5 When the fluctuation of the DC bus current exceeds the second preset threshold, immediately S pThe circuit is opened to protect the electrolytic cell, while the controlled variable impedance device is quickly adjusted to discharge mode to consume transient energy.

[0065] Understandable, The stability is controlled by the new energy AC power generation system. dc1 and the control of new energy DC power generation system i dc2 And the adjustment control of the controlled variable impedance device This is ensured by dynamically adjusting three currents. That is,

[0066]

[0067] In the formula, It is the current i during the operation of the electrolytic cell. dc1 It is a direct current controlled by a new energy AC power generation system, i dc2 It is a DC current controlled by a new energy DC power generation system. It is a controlled adjustment of the variable impedance device.

[0068] It is understandable that the logical order of dynamic adjustment is as follows: the power generation side has the highest priority: when i dc1 and i dc2 When both exist, the power source with the larger generating capacity is considered the main power source, and its regulation priority is the highest; when i dc1 or i dc2 When existing independently, any one of the power sources is considered as the main power source.

[0069] Load regulation side is the second priority: after the first priority generation side current stabilization control adjustment, Adjusted as the second priority.

[0070] The current is adjusted in stages to avoid instability caused by frequent system adjustments.

[0071] Understandably, when the fluctuation of the DC bus current exceeds the second preset threshold, it is necessary to calculate S. p First, clear the way, S Z Transient energy input will be absorbed by a controlled, adjustable variable impedance device to prevent further system degradation and ensure equipment safety. New energy AC or DC power generation systems can accommodate and disconnect different forms of new energy generation according to system requirements.

[0072] When a new energy power generation system malfunctions, the energy storage inductor L can be used to resolve the issue. dc1 L dc2 or L dc3 L dc4Its energy storage function ensures the safe disconnection of the electrolytic cell while disconnecting faulty AC current source converters and DC current source converters, thereby improving the safety of the electrolytic cell system.

[0073] As can be seen from the above technical solution, the current source system and its control method for green hydrogen production provided in this embodiment include: a new energy AC power generation system, a new energy DC power generation system, an AC current source converter, a DC current source converter, a three-phase transformer, a single-phase transformer, a controlled adjustable variable impedance device, an electrolyzer, etc. The method includes: the power source for green hydrogen production comes from the AC or DC power generation system of the new energy power generation system; the AC current source converter acts as the controller for the AC power generation system of the new energy AC power generation system, such as an AC wind turbine or a photovoltaic power generation system; the DC current source converter acts as the controller for the DC power generation system of the new energy DC power generation system, such as a DC wind turbine or a photovoltaic power generation system, respectively realizing the conversion of wind power or photovoltaic power generation; the AC current source converter adopts dual closed-loop direct current control, and the DC current source converter adopts dual closed-loop direct current control; the three-phase and single-phase transformers are used for voltage level conversion; the controlled adjustable variable impedance device serves as an accessory to balance the impedance of the electrolyzer, which can improve the current control capability and, in the event of a DC bus fault, acts as an energy leakage bypass, improving the safety of the electrolyzer; dc1 i dc2 , Optimal scheduling is achieved based on a current allocation optimization mechanism, which is as follows: S1 ensures optimal scheduling by dynamically adjusting three aspects: the dual-closed-loop AC control strategy of the new energy AC power generation system, the dual-closed-loop DC control strategy of the new energy DC power generation system, and the adjustment of the controlled adjustable variable impedance device. Stable; S2 when i dc1 +i dc2 Output capability greater than When required, adjustments are needed at this time. To ensure Stable; S3 when i dc1 +i dc2 Output capability less than When required, adjustments are needed at this time. It is zero, that is, S Z Open path; S4 when i dc1 i dc2 When the fluctuation in the control exceeds the first preset threshold, the impedance value of the variable impedance device is dynamically adjusted, thereby changing the electrolytic cell current. S5 When the fluctuation of the DC bus current exceeds the second preset threshold, immediately S pAn open circuit is used to protect the electrolyzer's safety, while a controlled variable impedance device quickly adjusts to a discharge mode to dissipate transient energy. This invention allows for the connection and disconnection of different renewable energy generation methods according to system requirements, providing multiple safeguards for stable and safe power supply to the electrolyzer, obtaining a power source for green hydrogen production, and improving the accuracy of electrolyzer current control. The control method provided by this invention can be extended to other similar applications beyond refineries.

[0074] Furthermore, in this invention, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0075] Furthermore, in this invention, the use of terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refers to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Furthermore, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0076] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A current source system for green hydrogen production, characterized in that, include: New energy AC power generation system, new energy DC power generation system, AC current source converter, DC current source converter, three-phase transformer, single-phase transformer and impedance controllable and stable load, wherein the impedance controllable and stable load includes a controlled adjustable variable impedance device and an electrolytic cell; Among them, the new energy AC power generation system is connected to the AC current source converter through a three-phase transformer; the new energy DC power generation system is connected to the DC current source converter through a single-phase transformer; the impedance-controlled and stable load is connected to the AC current source converter and the DC current source converter; the three-phase transformer and the single-phase transformer realize the voltage level transformation between the power generation system and the current source converter to meet the control of the current and power of the electrolytic cell in the impedance-controlled and stable load; Among them, the voltage level transformation between the power generation system and the current source converter achieved by the three-phase transformer and the single-phase transformer refers to the voltage level transformation between the new energy AC power generation system or the new energy DC power generation system and the AC current source converter or the DC current source converter achieved by the three-phase transformer and the single-phase transformer. i dc1 , i dc2 , Optimized scheduling is achieved based on the current allocation optimization mechanism; The current distribution optimization mechanism includes: S1. Based on the dual-closed-loop AC control strategy of the new energy AC power generation system, the dual-closed-loop DC control strategy of the new energy DC power generation system, and the dynamic adjustment of the controlled adjustable variable impedance device, the system is guaranteed to function. Stablize; S2, when i dc1 + i dc2 Output capability greater than When required, adjustments are needed at this time. To ensure Stablize; S3, when i dc1 + i dc2 Output capability less than When required, adjustments are needed at this time. It is zero, that is, S Z open circuit; S4, when i dc1 , i dc2 When the fluctuation in the control exceeds the first preset threshold, the impedance value of the controlled variable impedance is dynamically adjusted, thereby changing the electrolytic cell current. ; S5. When the fluctuation of the DC bus current exceeds the second preset threshold, immediately S p Open circuit to protect the electrolytic cell, while the controlled variable impedance device quickly adjusts to discharge mode to consume transient energy; in, It is the current when the electrolytic cell is working. i dc1 It is a direct current controlled by a new energy AC power generation system. i dc2 It is a DC current controlled by a new energy DC power generation system.

2. The current source system for green hydrogen preparation according to claim 1, characterized in that, The power source for green hydrogen production comes from either the new energy AC power generation system or the new energy DC power generation system. The AC current source converter acts as the controller for both the AC wind turbine and the AC photovoltaic power generation system, both of which are new energy AC power generation systems. Similarly, the DC current source converter acts as the controller for both the DC wind turbine and the DC photovoltaic power generation system, both of which are new energy DC power generation systems. The AC current source converter converts wind power or photovoltaic power generated from new energy sources, and the DC current source converter also converts wind power or photovoltaic power generated from new energy sources. Both the AC and DC current source converters employ dual closed-loop direct current control. Three-phase and single-phase transformers are used for voltage level conversion. A controlled adjustable variable impedance device serves as an accessory to balance the impedance of the electrolyzer, thereby improving current control capability. The new energy AC power generation system is connected to the AC current source converter via the three-phase transformer; the new energy DC power generation system is connected to the DC current source converter via the single-phase transformer; the impedance-controllable and stable adjustable load is connected to the output terminals of the AC current source converter and the DC current source converter respectively, and the impedance-controllable and stable adjustable load includes the controlled adjustable variable impedance device and the electrolytic cell connected in parallel.

3. The current source system for green hydrogen preparation according to claim 2, characterized in that, The stability is controlled by the new energy AC power generation system. i dc1 and control of new energy DC power generation systems i dc2 And the adjustment control of the controlled variable impedance device The dynamic adjustment of three currents ensures that, namely: = i dc1 + i dc2 - 。 4. The current source system for green hydrogen preparation according to claim 3, characterized in that, The logical order of dynamic adjustment is as follows: The power generation side is the first priority: when i dc1 and i dc2 When both exist, the power source with the largest generating capacity is considered the main power source, and its regulation priority is the highest; when i dc1 or i dc2 When existing independently, any one of the power sources is considered as the main power source; Load regulation side is the second priority: after the first priority generation side current stabilization control adjustment, Adjusted as the second priority; The current is adjusted in stages to avoid instability caused by frequent system adjustments.

5. The current source system for green hydrogen preparation according to claim 2 or 3, characterized in that, When the fluctuation of the DC bus current exceeds the second preset threshold, it is necessary to calculate S. p First, clear the way, S Z By maintaining the connection, transient energy will be absorbed by a controlled adjustable variable impedance device, preventing further system degradation and ensuring equipment safety.

6. The current source system for green hydrogen preparation according to any one of claims 2-4, characterized in that, New energy AC power generation systems or new energy DC power generation systems can connect to and disconnect different forms of new energy power generation according to system requirements.

7. The current source system for green hydrogen preparation according to any one of claims 2-4, characterized in that, When a new energy power generation system malfunctions, the energy storage inductor... L dc1 , L dc2 or L dc3 , L dc4 Its energy storage function ensures the safe disconnection of the electrolytic cell while disconnecting faulty AC current source converters and DC current source converters, thereby improving the safety of the electrolytic cell system.

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