Wind-hydrogen coupling system based on chain distribution strategy and control method thereof

Abstract

The application discloses a wind-hydrogen coupling system based on a chain distribution strategy and a control method thereof, which comprises a direct-drive permanent magnet wind power generation system, a voltage conversion system, a water electrolysis hydrogen production system and an energy distribution system; the direct-drive permanent magnet wind power generation system is used for capturing wind energy and converting the wind energy into mechanical energy and then into high-voltage electric energy; the voltage conversion system is used for converting the high-voltage electric energy generated by the direct-drive permanent magnet wind power generation system into stable low-voltage direct-current electric energy and inputting the low-voltage direct-current electric energy into the water electrolysis hydrogen production system; the water electrolysis hydrogen production system is composed of at least one proton exchange membrane electrolysis cell (PEMEL) single stack and is used for electrolyzing water to prepare hydrogen; the energy control system is based on the chain distribution strategy, is coupled with a plurality of MIBC control systems and corresponding PEMEL single stacks, performs power distribution, and guarantees stable and efficient operation of the water electrolysis hydrogen production system. The application can effectively consume abandoned wind power, improves the hydrogen production reliability of the system, and effectively solves the problems of abandoned wind power coupling control and power distribution.

Description

Technical Field

[0001] The present invention relates to the technical field of hydrogen production from energy, and in particular to a wind-hydrogen coupling system based on a chain distribution strategy and a control method thereof. Background Art

[0002] According to statistics from the National Energy Administration, as of November 2021, my country's grid-connected wind power installed capacity reached 300.15 million kilowatts, surpassing the 300 million kilowatt mark and ranking first globally for 12 consecutive years. As grid-connected wind power capacity continues to increase, insufficient wind power absorption capacity, resulting in inadequate grid integration, has gradually emerged. The rational use of energy storage technology to maintain a high wind power grid connection rate, overcome the randomness and volatility of wind power generation, and reduce wind curtailment remains a pressing issue.

[0003] As a clean energy source, hydrogen boasts high energy density, large capacity, long lifespan, and ease of storage and transportation, making it a preferred option for the large-scale, comprehensive development and utilization of wind power. However, traditional hydrogen production by electrolysis operates at a fixed hydrogen production rate under stable power conditions, resulting in low power levels for individual electrolyzers. However, the amount of wind power curtailed is intermittent, highly random, and has high power levels. Current technologies focus less on the selection, configuration, testing, and optimization of key equipment such as system operation strategies and DC / DC converters. Consequently, the coupling control and power allocation between wind curtailment and hydrogen production by electrolysis present significant challenges. Summary of the Invention

[0004] To solve the above technical problems, the present invention proposes a wind-hydrogen coupling system based on a chain distribution strategy, comprising: a direct-drive permanent magnet wind power generation system, a voltage transformation system, a water electrolysis hydrogen production system and an energy distribution system;

[0005] The direct-drive permanent magnet wind power generation system is used to capture wind energy, convert it into mechanical energy and then convert it into high-voltage electrical energy;

[0006] The transformer system is used to convert the abandoned wind power that cannot be connected to the grid and transmitted or consumed locally in the high-voltage electric energy generated by the direct-drive permanent magnet wind power generation system into stable low-voltage direct current and input it into the water electrolysis hydrogen production system.

[0007] The water electrolysis hydrogen production system is composed of at least one proton exchange membrane electrolyzer PEMEL single stack, which is used to electrolyze water to produce hydrogen;

[0008] The energy control system is used to calculate the allocated power of each PEMEL single stack in real time, allocate the abandoned wind power to the water electrolysis hydrogen production system, and ensure the stable and efficient operation of the water electrolysis hydrogen production system.

[0009] Preferably, the transformer system is an MIBC structure, including a two-phase staggered parallel buck circuit and capacitors C1, C2, C3 and C4; the capacitors C1 and C2 are connected in series and in parallel with the input voltage, and the capacitors C3 and C4 are connected in series and connected between the switching tubes.

[0010] Preferably, the MIBC structure controls the on and off of the switching devices of the MIBC structure through a power PI regulator and a current PI regulator to construct an MIBC control system.

[0011] Preferably, the energy control system sets the maximum reference power of each PEMEL single stack based on a chain allocation strategy, collects the power of abandoned wind power, calculates the real-time allocated power of the nth PEMEL single stack through the chain allocation strategy, and generates a PWM control quantity through the MIBC control system corresponding to each PEMEL single stack, adjusts the opening and closing time of the switching device, so that each PEMEL single stack operates according to the power value allocated by the system to produce hydrogen.

[0012] Accordingly, the present invention also provides a control method for a wind-hydrogen coupling system based on a chain allocation strategy, comprising the following steps:

[0013] Step S1: The direct-drive permanent magnet wind power generation system converts wind energy into high-voltage electrical energy, wherein the abandoned wind energy that cannot be connected to the grid or is consumed locally is transmitted to the current bus;

[0014] Step S2: The energy control system calculates the real-time distributed power of each PEMEL stack.

[0015] Step S3: The real-time distributed power of each PEMEL stack calculated in step S2 is input into the MIBC control system corresponding to each PEMEL stack, the on-off time of the switch components of the MIBC control system is adjusted, and the abandoned wind power in the current bus is converted into low-voltage direct current and transmitted to each PEMEL stack for hydrogen production.

[0016] Preferably, the specific steps of calculating the real-time allocated power in step S2 are:

[0017] Step S21: deriving the MIBC control system transfer function and calculating the control parameters of the power PI regulator and the current PI regulator;

[0018] Step S22: Power allocation calculation, setting the maximum reference power P of each PEMEL stack elmax , abandoned wind power P wind , calculate the real-time distribution power P of the nth PEMEL single stack through the chain allocation strategy refn .

[0019] Preferably, step S21 is specifically as follows:

[0020] Step S211: Calculate the step-down ratio K and current ripple Δi of the MIBC control system using the following formula: o , switching device voltage stress V S :

[0021] (1)

[0022] (2)

[0023] (3)

[0024] Where V o Indicates the output voltage, V dc represents the input voltage, D represents the duty cycle of the switching device, L represents the output inductance, L=L1=L2, L1 and L2 are the two output inductors of MIBC, f s Indicates the switching frequency of the switching device, V S1 、V S2 、V S3 and V S4 Represents the voltage across the switches S1, S2, S3, and S4.

[0025] Step S212: Analyze the working condition of the MIBC control system within one switching cycle by the state space averaging method, and obtain the average state equation according to Kirchhoff's law:

[0026] (4)

[0027] Where i1 and i2 represent the currents passing through L1 and L2 respectively, and C o represents output capacitance, R represents output resistance, and t represents time;

[0028] Step S213: Establish a small signal mathematical model:

[0029] (5)

[0030] Step S214: Substitute equations (1) and (5) into equation (4) to calculate:

[0031] (6)

[0032] Step S15: Set i1=i2=i L , perform Laplace transform on Equation (6):

[0033] (7)

[0034] wherein s represents a Laplace transform factor;

[0035] Step S216: transforming formula (7) to obtain a transfer function G of the MIBC control system i (s) is:

[0036] (8)

[0037] Step S17: according to the transfer function, selecting parameter values of the power PI regulator and the current PI regulator suitable for system operation through an amplitude-phase characteristic curve.

[0038] Preferably, the chain distribution strategy in step S22 specifically refers to sequentially starting each PEMEL single stack in a pre-arranged order, and the PEMEL single stack in a previous stage is operated to its maximum reference power P elmax After that, the PEMEL single stack in a next stage is started, and the power distribution of the PEMEL single stack that is not started is 0.

[0039] Preferably, step S3 specifically refers to that the MIBC control system corresponding to each PEMEL single stack calculates a current reference value through the power PI controller by subtracting the real-time distribution power received by the PEMEL single stack from the real-time power of the PEMEL single stack, and generates a PWM control amount through the current PI controller by subtracting the real-time current from the amplitude limiting link, so as to adjust the turn-on and turn-off time of the switching device of the MIBC control system, so that each PEMEL single stack generates hydrogen according to the real-time distribution power.

[0040] Preferably, at least one PEMEL backup stack is arranged, and when one or more of the plurality of PEMEL single stacks fails to operate, the PEMEL backup stack is started to undertake power generation of these PEMEL single stacks, so as to ensure stable operation of the system.

[0041] Compared with the closest prior art, the technical scheme provided by the present application has the following beneficial effects:

[0042] 1) The MIBC control system can directly reduce the high voltage on the abandoned wind side to the range of the allowable operating voltage of the PEMEL, the one-time voltage reduction capacity of the system is improved by 4 times, the voltage stress of the switching device is not higher than 1 / 2 of the input voltage, the use of power electronic intermediate equipment is reduced, and the system harmonic is reduced.

[0043] 2) The rapid load variation and wide range regulation capacity of the PEMEL allow the system to select the power distribution strategy without considering multiple complex indexes, thereby simplifying the control link.

[0044] 3) The chain power distribution strategy and the setting of PEMEL backup stacks ensure that the system can quickly start the backup stack and redistribute the power within 10 minutes when one or more single stacks are shut down, so that the system can continue to work normally and has high reliability.

[0045] 4) Except for part of the equipment and transmission loss, the abandoned wind power in the wind-hydro coupling system is used for hydrogen production by electrolysis, and the abandoned wind power utilization rate is increased to more than 95%. BRIEF DESCRIPTION OF DRAWINGS

[0046] Figure 1 The structure block diagram of a wind-hydro coupling system and a control method based on a chain distribution strategy in an embodiment of the present application;

[0047] Figure 2 The topological structure diagram of the MIBC structure in the embodiment of the present application;

[0048] Figure 3 The voltage stress V o of the switching device, the current ripple Δi S of the MIBC control system in the embodiment of the present application;

[0049] Figure 4 The structure diagram of the MIBC control system in the embodiment of the present application;

[0050] Figure 5 The equivalent circuit model of the PEMEL single stack in the embodiment of the present application;

[0051] Figure 6 The electrical external characteristic curve diagram of the equivalent circuit model of the PEMEL single stack in the embodiment of the present application;

[0052] Figure 7 The wind-hydro coupling circuit structure diagram of the PEMEL single stack in the embodiment of the present application;

[0053] Figure 8 The mathematical model diagram of the MIBC control system in the embodiment of the present application;

[0054] Figure 9 The dynamic characteristic curve diagram of the MIBC control system in the embodiment of the present application;

[0055] Figure 10 The topological diagram of a wind-hydro coupling system and a control method based on a chain distribution strategy in the embodiment of the present application;

[0056] Figure 11 The output power curve diagram of a small wind turbine in Shantou Nan'ao East Peninsula wind farm on November 12-24, 2021 in the embodiment of the present application;

[0057] Figure 12This is a schematic diagram of the operation of a four-stack PEMEL wind-hydrogen coupling system in an embodiment of the present invention. DETAILED DESCRIPTION

[0058] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0059] The terms used in the embodiments of the present invention are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The singular forms "a," "an," and "the" used in the embodiments of the present invention and the appended claims are also intended to include plural forms unless the context clearly indicates otherwise. It should also be understood that the term "and / or" used herein refers to and includes any or all possible combinations of one or more associated listed items.

[0060] like Figure 1 As shown, a structural diagram of a wind-hydrogen coupling system based on a chain allocation strategy provided by an embodiment of the present invention is shown. For ease of description, only the parts related to the embodiment of the present invention are described, which are detailed as follows:

[0061] The wind-hydrogen coupling system in the embodiment of the present invention includes a direct-drive permanent magnet wind power generation system, a voltage transformation system, a water electrolysis hydrogen production system and an energy distribution system;

[0062] Direct-drive permanent magnet wind power generation system is used to convert wind energy into mechanical energy and then into high-voltage electrical energy.

[0063] The transformer system is connected to the water electrolysis hydrogen production system and is used to convert the high-voltage electricity generated by the direct-drive permanent magnet wind power generation system that cannot be connected to the grid for transmission or is forced to be abandoned due to local consumption into stable low-voltage direct current, and transmit it to the water electrolysis hydrogen production system to power the water electrolysis hydrogen production system. In the embodiment of the present invention, this part of electricity is called abandoned wind power.

[0064] The water electrolysis hydrogen production system is used to absorb the abandoned wind power to produce hydrogen by water electrolysis. In the embodiment of the present invention, the water electrolysis hydrogen production system is composed of at least one proton exchange membrane electrolyzer PEMEL.

[0065] The energy control system is used to calculate the allocated power of the PEMEL single stack in real time, allocate the abandoned wind power to the water electrolysis hydrogen production system, and ensure the stable and efficient operation of the water electrolysis hydrogen production system.

[0066] In the embodiment of the present invention, the transformer system adopts Figure 2Specifically, the MIBC structure shown is a conventional two-phase interleaved parallel high step-down ratio interleaved Buck converter with the addition of four capacitors. C1 and C2 are connected in series and in parallel with the input voltage, while C3 and C4 are connected in series between the switches. C1 and C2 are charged by the input voltage and discharged to the two-phase interleaved parallel Buck converter with C3 and C4. This achieves a high step-down ratio without the need for a small duty cycle. Furthermore, based on the principle of capacitive voltage division, the converter can store energy in the input capacitor, reducing the voltage stress of the switching devices.

[0067] like Figure 3 As shown, in order to verify the static characteristics of MIBC in the embodiment of the present invention, current control is applied to MIBC, and the input DC voltage V is set. dc =300V, switching frequency of the switching device f s =100kHz, output inductance L=250μH, current reference value I ref =50A.

[0068] When the duty cycle D drops to 0.14, the current stabilizes at 50A; the current ripple Δi o Maintained at around 0.28A; the maximum voltage stress is approximately 150V, no higher than 1 / 2 of the input voltage, and V S4 The maximum value is only about 80V, which verifies the characteristics of MIBC's high voltage drop, low current ripple, and low voltage stress.

[0069] like Figure 4 As shown, the MIBC structure in the embodiment of the present invention controls the on and off of the switching devices of the MIBC structure through a power PI regulator and a current PI regulator to construct an MIBC control system.

[0070] The PEMEL power reference value is input into the power loop. After subtracting it from the PEMEL power real-time measurement value, the power error value is input into the power PI regulator to obtain the PEMEL current reference value. The PEMEL current reference value is used as the current loop input. After subtracting it from the PEMEL current real-time measurement value, the current error value is input into the current PI regulator to obtain the real-time trigger signal of the MIBC switching device. The switching device is controlled to operate according to the duty cycle given by the real-time trigger signal, completing the dual closed-loop control of the MIBC control system.

[0071] like Figure 5 As shown in FIG, the PEMEL proposed in the present invention adopts an equivalent circuit model that can characterize its charge transfer effect and electrothermal loss.

[0072] The PEMEL equivalent circuit model equates the charge transfer between the anode and cathode to capacitors C1 and C2, and equates the cathode heat loss, transmembrane transport loss, and anode heat loss to resistors R1 and R2. int 、R2,Vint Multiply it by the current to express the hydrogen production power.

[0073] like Figure 6 As shown, in order to verify the electrical external characteristics of the PEMEL single stack equivalent circuit model in the embodiment of the present invention, a step current is applied to the model to prove that the model can well reflect the PEMEL charge transfer effect and electrothermal loss characteristics.

[0074] like Figure 7 As shown, the energy control system in the embodiment of the present invention is coupled by multiple MIBC control systems and the corresponding PEMEL single stacks, expanding from the PEMEL single stack structure to multiple stacks for coordinated operation and power distribution, ensuring stable and efficient operation of the water electrolysis hydrogen production system.

[0075] The present invention also provides a control method for a wind-hydrogen coupling system based on a chain allocation strategy, comprising the following steps:

[0076] Step S1: The direct-drive permanent magnet wind power generation system converts wind energy into high-voltage electrical energy, wherein the abandoned wind energy that cannot be connected to the grid or is consumed locally is transmitted to the current bus;

[0077] Step S2: The energy control system calculates the real-time distributed power of each PEMEL stack.

[0078] Step S3: The real-time distributed power of each PEMEL stack calculated in step S2 is input into the MIBC control system corresponding to each PEMEL stack, the on-off time of the switch components of the MIBC control system is adjusted, and the abandoned wind power in the current bus is converted into low-voltage direct current and transmitted to each PEMEL stack for hydrogen production.

[0079] Wherein, step S2 is specifically as follows:

[0080] Step S21: deriving the MIBC control system transfer function and calculating the control parameters of the power PI regulator and the current PI regulator;

[0081] Step S22: Power allocation calculation, setting the maximum reference power P of each PEMEL stack elmax , abandoned wind power P wind , calculate the real-time distribution power P of the nth PEMEL single stack through the chain allocation strategy refn .

[0082] Step S21 is specifically as follows:

[0083] Step S211: Calculate the step-down ratio K and current ripple Δi of the MIBC control system using the following formula: o , switching device voltage stress VS :

[0084] (1)

[0085] (2)

[0086] (3)

[0087] Where V o Indicates the output voltage, V dc represents the input voltage, D represents the duty cycle of the switching device, L represents the output inductance, L=L1=L2, L1 and L2 are the two output inductors of MIBC, f s Indicates the switching frequency of the switching device, V S1 、V S2 、V S3 and V S4 Represents the voltage across the switches S1, S2, S3, and S4.

[0088] Step S212: Analyze the working condition of the MIBC control system within one switching cycle by the state space averaging method, and obtain the average state equation according to Kirchhoff's law:

[0089] (4)

[0090] Where i1 and i2 represent the currents passing through L1 and L2 respectively, and C o represents output capacitance, R represents output resistance, and t represents time;

[0091] Step S213: Establish a small signal mathematical model:

[0092] (5)

[0093] Step S214: Substitute equations (1) and (5) into equation (4) to calculate:

[0094] (6)

[0095] Step S215: Set i1=i2=i L , perform Laplace transform on Equation (6):

[0096] (7)

[0097] Where s represents the Laplace transform factor;

[0098] Step S216: Transform equation (7) to obtain the transfer function G of the MIBC control system i (s) is:

[0099] (8)

[0100] Step S217: According to the topological structure of the MIBC control system and the transfer function, select the PI parameter value suitable for the system operation through the amplitude-phase characteristic curve. In this embodiment, k is taken as Pp =0.01, k Pi =50,k Ip =0.01, k Ii =100, where k Pp 、k Pi is the power PI controller parameter, k Ip 、k Ii are the current PI controller parameters.

[0101] like Figure 8 As shown in the figure, the mathematical model of the MIBC control system established by the above analysis is composed of the transfer functions corresponding to the PEMEL power reference value, the PEMEL power real-time measurement value, the sampling delay link, the power PI regulator, the current PI regulator, the PWM gain coefficient, and the MIBC. The model is connected according to the position of each part in the MIBC double closed-loop control structure. Specifically, after the PEMEL power reference value is input into the mathematical model, it is calculated according to the transfer function of each part and the connection method shown in the figure to obtain the real-time control quantity, and then the system is corrected to work according to the input reference value. Since the MIBC control system proposed in the present invention is a two-phase staggered parallel structure, the current reference value is divided into two identical paths for calculation. Among them, k PWM is the PWM gain coefficient, T s is the sampling delay coefficient.

[0102] like Figure 9 As shown, in order to verify the dynamic characteristics of the mathematical model of the MIBC control system in the embodiment of the present invention, the MIBC input voltage V dc and PEMEL power reference value P ref , the other parameters are the same as above. It can be seen that when the input voltage V dc And the power reference value P ref When a single or simultaneous ramp change occurs, the actual power value is within the acceptable range, with a certain fluctuation within less than 100W, which basically meets the requirements of followability and rapidity; in 0.4s, the input voltage V dc When a 100V step change occurs, the actual power value only shows an overshoot of about 60W and returns to stability after 5ms, indicating that the MIBC control system has strong stability and anti-interference capabilities.

[0103] The chain allocation strategy in step S22 is specifically that the PEMEL single stacks are put into operation step by step according to the pre-arranged order, and the previous PEMEL single stack is operated to its maximum reference power P elmax After that, the next level PEMEL single stack is started, and the power allocation of the unstarted single stack is 0.

[0104] Step S3 specifically includes: the MIBC control system corresponding to each PEMEL single stack subtracts the received real-time allocated power from the real-time power of the PEMEL single stack, calculates a current reference value through the power PI controller, and subtracts it from the real-time current through a limiting link, generates a PWM control variable through the current PI controller, adjusts the on and off time of the switching device of the MIBC control system, and enables each PEMEL single stack to produce hydrogen according to the real-time allocated power, thereby achieving the effect of real-time power distribution.

[0105] A topological diagram of a control method for a wind-hydrogen coupling system based on a chain allocation strategy in an embodiment of the present invention is shown in FIG. Figure 10 As shown in the figure, each PEMEL stack is coupled in parallel to the wind power curtailment busbar through its own MIBC control system to achieve independent control of each PEMEL stack.

[0106] When one or more PEMEL stacks fail and stop running, the system starts the backup PEMEL stack and distributes the power borne by these PEMEL stacks to other PEMEL stacks, and the system continues to operate normally.

[0107] In an embodiment of the present invention, a wind-hydrogen coupling system based on a chain allocation strategy further includes auxiliary equipment. Auxiliary equipment refers to auxiliary equipment other than the main equipment, such as filters, circuit breakers, hydrogen (oxygen) gas separation purifiers, water tanks and water pumps required by the system.

[0108] In order to verify the effectiveness and feasibility of the wind-hydrogen coupling system based on the chain distribution strategy and its control method proposed in this invention, a Simulink simulation model of the system was established in Matlab software. Figure 11 The output power of a small wind turbine at the Shantou Nan'ao East Peninsula Wind Farm from 12 to 24 hours on a certain day in November 2021 is shown as the input of the system's abandoned wind power.

[0109] During this period, the output power of the abandoned wind power fluctuates between 0.7 kW and 8.8 kW. Therefore, three 3 kW single-stack PEMELs are required. In order to simulate the failure of a PEMEL during operation, the system is equipped with four single-stack PEMELs. The operation diagram of the four-stack PEMEL wind-hydrogen coupling system is shown in the figure. Figure 12 shown.

[0110] At 12h, the wind-hydrogen coupling system with multiple stacks based on the chain allocation strategy was started and operated. Initially, the wind curtailment power was less than 3kW, and only the No. 1 PEMEL stack was started and operated following the input power changes; at around 17h, the wind curtailment power gradually increased to more than 3kW, the No. 1 PEMEL stack reached the maximum operating power, and the No. 2 PEMEL stack was started; at around 18h, the No. 2 PEMEL stack was restarted after a short shutdown; subsequently, the wind curtailment power continued to increase, and the No. 3 PEMEL stack participated in the operation; at 20h, due to the long-term saturated operation of the No. 1 PEMEL stack, a fault occurred and the system needed to be exited for maintenance, and the spare No. 4 PEMEL stack was started, and No. 2 to No. 4 PEMELs took on the responsibility of absorbing the wind curtailment power and continued to maintain the normal hydrogen production of the system. It can be seen that the present invention has good wind curtailment power followability and can maintain a strong load-variable hydrogen production capability in the long-term wind curtailment power changes.

[0111] In terms of reliability, after the shutdown of PEMEL 1, the system immediately restarted PEMEL 4, completing the new power allocation approximately ten minutes later. Furthermore, the simulation model accounts for some losses in the MIBC and PEMELs, achieving a system curtailment efficiency of over 95%.

[0112] The technical features of the above-described embodiments may be combined in any manner. To simplify the description, not all possible combinations of the technical features in the above-described embodiments are described. Only preferred embodiments of the present invention are presented. While the description is relatively specific and detailed, it should not be construed as limiting the scope of the present invention. As long as there are no conflicts in the combination of these technical features, they should be considered to be within the scope of this specification.

[0113] It should be noted that those skilled in the art may make various modifications and improvements without departing from the scope of the present invention, and these modifications and improvements fall within the scope of protection of the present invention. Therefore, the scope of protection of the patent for this invention shall be based on the appended claims.

Claims

1. A control method for a wind-hydrogen coupling system based on a chain allocation strategy, wherein the method is implemented based on a wind-hydrogen coupling system based on a chain allocation strategy, and is characterized by: The system includes a direct-drive permanent magnet wind power generation system, a voltage transformation system, a water electrolysis hydrogen production system and an energy control system; The direct-drive permanent magnet wind power generation system is used to capture wind energy, convert it into mechanical energy and then convert it into high-voltage electrical energy; The transformer system is used to convert the abandoned wind power that cannot be connected to the grid or locally consumed in the high-voltage electric energy generated by the direct-drive permanent magnet wind power generation system into stable low-voltage direct current and input it into the water electrolysis hydrogen production system; The water electrolysis hydrogen production system is composed of at least one proton exchange membrane electrolyzer PEMEL single stack, which is used to electrolyze water to produce hydrogen; The energy control system is used to calculate the allocated power of each PEMEL single stack in real time, allocate the abandoned wind power to the water electrolysis hydrogen production system, and ensure the stable and efficient operation of the water electrolysis hydrogen production system; The transformer system is an MIBC structure, including a two-phase interleaved parallel buck circuit and capacitors C1, C2, C3, and C4; the capacitors C1 and C2 are connected in series and then connected in parallel with the input voltage, and the capacitors C3 and C4 are connected in series and then connected between the switching tubes; The MIBC structure controls the on and off of the MIBC structure switch devices through a power PI regulator and a current PI regulator to construct an MIBC control system; The energy control system sets the maximum reference power of each PEMEL single stack based on a chain allocation strategy, collects the power of the abandoned wind power, calculates the real-time allocated power of the nth PEMEL single stack through the chain allocation strategy, and generates a PWM control variable through the MIBC control system corresponding to each PEMEL single stack, adjusts the on and off time of the switching device, so that each PEMEL single stack operates according to the power value allocated by the system to produce hydrogen; The method comprises the following steps: Step S1: The direct-drive permanent magnet wind power generation system converts wind energy into high-voltage electrical energy, and transmits the abandoned wind energy that cannot be connected to the grid or cannot be consumed locally to the current bus; Step S2: the energy control system calculates the real-time distributed power of each of the PEMEL single stacks; Step S3: inputting the real-time distributed power of each PEMEL stack calculated in step S2 into the MIBC control system corresponding to each PEMEL stack, adjusting the on and off times of the switch components of the MIBC control system, converting the abandoned wind power in the current bus into low-voltage direct current and transmitting the low-voltage direct current to each PEMEL stack for hydrogen production; The specific steps for calculating the real-time distributed power in step S2 are: Step S21: deriving the MIBC control system transfer function and calculating the control parameters of the power PI regulator and the current PI regulator; Step S22: Power allocation calculation, setting the maximum reference power P of each PEMEL stack elmax , abandoned wind power P wind , calculate the real-time distribution power P of the nth PEMEL single stack through the chain allocation strategy refn ; Step S21 is specifically as follows: Step S211: Calculate the step-down ratio K and current ripple Δi of the MIBC control system using the following formula: o , switching device voltage stress V S : （1） （2） （3） Where V o Indicates the output voltage, V dc represents the input voltage, D represents the duty cycle of the switching device, L represents the output inductance, L=L1=L2, L1 and L2 are the two output inductors of MIBC, f s Indicates the switching frequency of the switching device, V S1 、V S2 、V S3 and V S4 Represents the voltage across the switches S1, S2, S3, and S4; Step S212: Analyze the working condition of the MIBC control system within one switching cycle by the state space averaging method, and obtain the average state equation according to Kirchhoff's law: （4） Where i1 and i2 represent the currents passing through L1 and L2 respectively, and C o represents output capacitance, R represents output resistance, and t represents time; Step S213: Establish a small signal mathematical model: （5） Step S214: Substitute equations (1) and (5) into equation (4) to calculate: （6） Step S215: Set i1=i2=i L , perform Laplace transform on Equation (6): （7） Where s represents the Laplace transform factor; Step S216: Transform equation (7) to obtain the transfer function G of the MIBC control system i (s) is: （8） Step S217: According to the transfer function, parameter values ​​of the power PI regulator and the current PI regulator suitable for system operation are selected through the amplitude-phase characteristic curve.

2. The control method of a wind-hydrogen coupling system based on a chain allocation strategy according to claim 1, characterized in that: In step S22, the chain allocation strategy is specifically that each PEMEL stack is put into operation step by step according to the pre-arranged order, and the previous PEMEL stack is operated to its maximum reference power P elmax After that, the next level of PEMEL single stack is started. The power allocation of the unstarted PEMEL single stack is 0.

3. The control method of a wind-hydrogen coupling system based on a chain allocation strategy according to claim 1, characterized in that: Step S3 is specifically as follows: the MIBC control system corresponding to each PEMEL single stack subtracts the received real-time allocated power from the real-time power of the PEMEL single stack, calculates a current reference value through the power PI regulator, and subtracts it from the real-time current through a limiting link, generates a PWM control variable through the current PI regulator, adjusts the on and off time of the switching device of the MIBC control system, and enables each PEMEL single stack to produce hydrogen according to the real-time allocated power.

4. A control method for a wind-hydrogen coupling system based on a chain allocation strategy according to any one of claims 1 to 3, characterized in that: At least one PEMEL backup stack is set up. When one or more of the multiple PEMEL single stacks fail and stop operating, the PEMEL backup stack is started to take on the power generation load of these PEMEL single stacks to ensure smooth operation of the system.

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