Wind power hydrogen production system and operation strategy

Abstract

The invention relates to a wind power hydrogen production system and an operation strategy, and relates to the technical field of hydrogen energy, the wind power hydrogen production system comprises a distributed wind power unit, a mixed electrolytic cell array, an energy storage unit and an alternating current power grid; the distributed wind power unit is connected with the wind power collection bus, the alternating current power grid is connected with the wind power collection bus through the transformer, the energy storage unit is connected with the wind power collection bus, and the hybrid electrolytic cell array is connected with the wind power collection bus. A wind-hydrogen-storage integrated system is constructed, an alkaline electrolytic cell and a proton exchange membrane electrolytic cell are arranged in a mixed electrolytic cell array according to the capacity configuration proportion of 2: 1, grouped operation is carried out according to a rated state and a fluctuation state, the function advantages of the electrolytic cells in different operation groups are exerted, and reasonable distribution of hydrogen production power of the mixed electrolytic cells in a wind power hydrogen production system is achieved.

Description

Technical Field

[0001] The present disclosure relates to the field of hydrogen energy technology, and in particular to a wind power hydrogen production system and an operation strategy. Background Art

[0002] In the context of building a new power system with new energy as the main body, the use of renewable energy such as wind power generation to produce "green hydrogen" can achieve efficient use of clean energy. Among them, distributed wind power has the advantages of multi-point access, local consumption, and alleviating the power shortage in the load center. It converts distributed wind power into hydrogen energy that is easy to store on a large scale and used in a diversified manner according to local conditions, helping to achieve the "dual carbon" goal. In the application of distributed wind power hydrogen production system, a single type of electrolyzer is difficult to adapt to the impact of random fluctuations in wind power under multiple time scales. Therefore, combining the operating characteristics of alkaline electrolyzer AEL and proton exchange membrane electrolyzer PEMEL, constructing a hybrid electrolyzer array is an effective measure to ensure the stable operation of the system under fluctuating wind speed. In addition, a flexible rotation control strategy for the hybrid electrolyzer system can balance the use loss of each electrolyzer monomer and further improve the overall service life of the electrolyzer array. Based on what method to formulate a reasonable operation strategy to enhance the stable operation capability of the distributed wind power hydrogen production system and realize the reasonable power distribution of the hybrid electrolyzer has become one of the key research directions for the integration and development of wind power hydrogen production.

[0003] The current wind power hydrogen production system control strategy mainly focuses on the energy management and scheduling between each module and the electrolyzer, and there is little research on the coordinated operation of multiple electrolyzer arrays. Most of the existing electrolyzer arrays are composed of a single electrolyzer. For single AEL hydrogen production, there are problems such as poor dynamic response capability and high initial investment cost and high operation and maintenance cost of single PEM electrolyzer hydrogen production. Some studies focus on considering the operating characteristics of different electrolyzers, combining proton exchange membrane electrolyzers and alkaline electrolyzers to replace the hydrogen production system of a single type of electrolyzer, and proposing an ALK-PEM electrolysis hydrogen production system capacity optimization model to improve the economic benefits of the hydrogen production system, but the design of the hybrid electrolyzer control strategy is not comprehensive enough. The hybrid hydrogen production power generation system proposed in some studies can improve the adaptability and economy of the hydrogen production system and fluctuating power sources. Through the power allocation strategy, the state consistency between the electrolyzer arrays can be effectively guaranteed. Although the fluctuating power time can be evenly divided, the electrolyzers will switch between different states, affecting the energy utilization of the system. Taking all the above studies into consideration, most of them regard the electrolyzer array as a whole as an energy storage system, and only consider the equal distribution of operating time. The purpose is to be grid-friendly, and the operating status and power distribution of the single cells are not fully considered, resulting in the electrolyzer switching between different operating states, affecting the hydrogen production efficiency of the system. Summary of the invention

[0004] In order to solve the above technical problems, the present disclosure provides a wind power hydrogen production system and operation strategy for reasonably exerting the role and advantages of electrolyzers in different operation groups, improving the system energy utilization and dynamic electricity-hydrogen coupling capability, and improving hydrogen production efficiency.

[0005] In a first aspect, the present disclosure provides a wind power hydrogen production system, comprising: a distributed wind power unit, a hybrid electrolyzer array, an energy storage unit, and an AC power grid; the output end of the distributed wind power unit is connected to a wind power collection bus, the AC power grid is connected in series with one end of a transformer, the other end of the transformer is connected to the wind power collection bus, the energy storage unit is connected to the wind power collection bus, and the hybrid electrolyzer array is connected to the wind power collection bus;

[0006] The capacity configuration ratio of the alkaline electrolyzer to the proton exchange membrane electrolyzer in the hybrid electrolyzer array is 2:1;

[0007] The hybrid electrolyzer array includes a rated group and a fluctuation group, wherein the rated group includes n alkaline electrolyzers, and the fluctuation group includes m proton exchange membrane electrolyzers, where n is greater than or equal to 1 and is an integer, and m is greater than or equal to 1 and is an integer. The rated power of the electrolyzers in the hybrid electrolyzer array is P N .

[0008] Optionally, the alkaline electrolyzer is configured to adopt direct power control, and at least one alkaline electrolyzer in the rated group is operated at a rated power P N Operation, or, all alkaline electrolyzers are stopped.

[0009] Optionally, the proton exchange membrane electrolyzer is configured to adopt additional power adjustment, and the proton exchange membrane electrolyzers in the fluctuation group operate with fluctuating power, wherein the minimum operating power P of the proton exchange membrane electrolyzer is min =20%P N , maximum operating power P max =120%P N , standby power P s =3%P N .

[0010] In a second aspect, based on the same inventive concept, the present disclosure provides an operation strategy for a wind power hydrogen production system, which is applied in the wind power hydrogen production system as described in the first aspect, including:

[0011] When the power consumed by the hybrid electrolyzer array is (m-1)P S +nP N +P min ≤P el <nP N +(m-1)P S +P max, it is determined that the hybrid electrolyzer array is in rated working condition, and at this time the hybrid electrolyzer array operates in mode one;

[0012] When the power consumed by the hybrid electrolyzer is (mk)P S +nP N +kP min ≤P el <nP N +(mk)P S +kP max , it is determined that the hybrid electrolyzer array is in an overload condition, and at this time the hybrid electrolyzer array operates in mode 2;

[0013] When the power required to be absorbed by the hybrid electrolyzer array is P el ≥nP N +P S +(m-1)P max , it is judged that the hybrid electrolyzer array is in an overload condition, and at this time the hybrid electrolyzer array operates in mode three;

[0014] When the power that the hybrid electrolyzer needs to absorb is (m-1)P S +P N +P min ≤P el <xP N +(m-1)P S +P max , it is judged that the hybrid electrolyzer array is in an underload condition, and at this time the hybrid electrolyzer array operates in mode four;

[0015] When the power that the hybrid electrolyzer array needs to absorb is (m-1)P S +P min ≤P el <(m-1)P S +P max , it is judged that the hybrid electrolyzer array is in an underload condition, and at this time the hybrid electrolyzer array operates in mode five;

[0016] When the power that the hybrid electrolyzer array needs to absorb is 0<P el <(m-1)P S +P min , it is determined that the hybrid electrolyzer array is in an underload condition, and at this time the hybrid electrolyzer array operates in mode six;

[0017] Among them, the real-time measured wind power of the system is P w , the power of the hybrid electrolyzer array is P el =(1-20%)P w , the power of the energy storage unit is P b The alkaline electrolytic cell in the rated group is numbered P r1 , P r2 , Pr3 …P rn The proton exchange membrane electrolyzer in the fluctuation group is numbered P f1 , P f2 …P fm .

[0018] Optionally, in the mode 1, all alkaline electrolyzers in the rated group are in operation, only one proton exchange membrane electrolyzer in the fluctuation group is in operation, and m-1 proton exchange membrane electrolyzers are on standby for rotation; the mixed integer segmented model outputs the instruction:

[0019]

[0020] Optionally, in the second mode, all alkaline electrolyzers in the rated group are in operation; the fluctuation group has k proton exchange membrane electrolyzers participating in the average sharing of the fluctuation power, and (mk) units participating in the standby rotation; the mixed integer segmented model output instruction is:

[0021]

[0022] After the rotation time T is reached,

[0023]

[0024] Optionally, in the third mode, all alkaline electrolyzers in the rated group are in operation; all proton exchange membrane electrolyzers in the fluctuation group are also in operation, operating in a rated or overloaded state, and excess power is absorbed by the energy storage system; the mixed integer segmented model output instruction is:

[0025]

[0026] Optionally, in the fourth mode, only one proton exchange membrane electrolyzer in the fluctuation group is in operation, and the remaining m-1 units are on standby for rotation; the rated group has x alkaline electrolyzers working in the rated state, and nx units are in the shutdown state; the mixed integer segmented model output instruction is:

[0027]

[0028] After the rotation time T is reached,

[0029]

[0030] Optionally, in the fifth mode, all alkaline electrolyzers in the rated group stop running; only one proton exchange membrane electrolyzer in the fluctuation group participates in the fluctuation operation, and the remaining m-1 are on standby for rotation; the mixed integer segmented model output instruction is:

[0031]

[0032] Optionally, in the sixth mode, at least one proton exchange membrane electrolyzer in the fluctuation group is maintained in the lowest ideal operating state, the others enter the standby state, the alkaline electrolyzer in the rated group stops operating, and the output instruction of the mixed integer segmented model is:

[0033]

[0034] Compared with the prior art, the technical solution provided by the embodiment of the present disclosure has the following advantages: the present disclosure combines distributed wind power with a hybrid electrolyzer array and a grid-type energy storage system to construct a wind-hydrogen-storage integrated system, with the goal of realizing a reasonable distribution of hydrogen production power of hybrid electrolyzers in a distributed wind power hydrogen production system, conducts in-depth research on the rotation optimization strategy of the hybrid electrolyzer array, proposes a hybrid electrolyzer group rotation control strategy based on power fuzzy segmentation, organically combines AEL and PEMEL to form a hybrid electrolyzer array, and operates in groups according to rated operation and fluctuating operation states. Then, a mixed integer segmented model algorithm is used to control the start and stop, operation state, and power consumption of each electrolyzer, in order to give full play to the role and advantages of electrolyzers in different operation groups and improve the system energy utilization and dynamic electric hydrogen coupling capability. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present disclosure and, together with the description, serve to explain the principles of the present disclosure.

[0036] 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, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0037] Figure 1 Shown is a topological diagram of a distributed wind power hydrogen production system provided by an embodiment of the present disclosure;

[0038] Figure 2 The figure shows a control strategy block diagram of a grid-type energy storage system provided by an embodiment of the present disclosure;

[0039] Figure 3 Shown is an AEL control block diagram provided by an embodiment of the present disclosure;

[0040] Figure 4 Shown is a diagram of AEL hydrogen production efficiency and hydrogen production rate provided by an embodiment of the present disclosure;

[0041] Figure 5 Shown is a PEMEL control block diagram provided by an embodiment of the present disclosure;

[0042] Figure 6Shown is a diagram of PEMEL hydrogen production efficiency and hydrogen production rate provided by an embodiment of the present disclosure;

[0043] Figure 7 FIG. 1 is a schematic diagram of a group rotation control strategy provided by an embodiment of the present disclosure;

[0044] Figure 8 Shown is a mixed integer piecewise model flow chart provided by an embodiment of the present disclosure;

[0045] Fig. 9 Shown is a schematic diagram of a typical wind speed and output torque, rotation speed, voltage, and current provided by an embodiment of the present disclosure;

[0046] Fig.10 The figure shows a schematic diagram of the overall operation of each unit of a wind power hydrogen production system provided by an embodiment of the present disclosure;

[0047] Fig.11 Shown is a schematic diagram of the operation of each unit of a hybrid electrolytic cell provided by an embodiment of the present disclosure;

[0048] Fig.12 Shown is a schematic diagram of the output of an energy storage unit provided in an embodiment of the present disclosure;

[0049] Fig.13 Shown is a schematic diagram of the operation of each electrolytic cell under a simple equal distribution strategy provided by an embodiment of the present disclosure;

[0050] Fig.14 Shown is a comparative analysis diagram of a group rotation control strategy based on fuzzy segmentation and a single PEM simple time averaging strategy provided by an embodiment of the present disclosure. DETAILED DESCRIPTION

[0051] In order to more clearly understand the above-mentioned objectives, features and advantages of the present disclosure, the scheme of the present disclosure will be further described below. It should be noted that the embodiments of the present disclosure and the features in the embodiments can be combined with each other without conflict.

[0052] In the following description, many specific details are set forth to facilitate a full understanding of the present disclosure, but the present disclosure may also be implemented in other ways different from those described herein; it is obvious that the embodiments in the specification are only part of the embodiments of the present disclosure, rather than all of the embodiments.

[0053] Figure 1 The figure shows a topological diagram of a distributed wind power hydrogen production system provided by the embodiment of the present disclosure. Please refer to Figure 1The present disclosure provides a wind power hydrogen production system 100, comprising: a distributed wind power unit 01, a hybrid electrolyzer array 03, an energy storage unit 02, and an AC power grid 04; the output end of the distributed wind power unit 01 is connected to a wind power collection bus, the AC power grid 04 is connected in series with one end of a transformer 05, the other end of the transformer 05 is connected to the wind power collection bus, the energy storage unit 02 is connected to the wind power collection bus, and the hybrid electrolyzer array 03 is connected to the wind power collection bus;

[0054] The capacity configuration ratio of the alkaline electrolyzer and the proton exchange membrane electrolyzer in the hybrid electrolyzer array 03 is 2:1;

[0055] The hybrid electrolyzer array 03 includes a rated group and a fluctuation group. The rated group includes n alkaline electrolyzers, and the fluctuation group includes m proton exchange membrane electrolyzers, where n ≥ 1 and is an integer, and m ≥ 1 and is an integer. The rated power of the electrolyzers in the hybrid electrolyzer array 03 is P N .

[0056] Specifically, in order to achieve the improvement of resource utilization and hydrogen production efficiency of the wind power hydrogen production system 100, the present disclosure constructs a hybrid electrolyzer hydrogen production system model, in which the distributed wind power unit 01 uses a direct-drive permanent magnet synchronous generator as an electrolysis power source, and the energy storage unit 02 uses a lithium iron phosphate battery. The energy storage unit 02 is used to release the stored electric energy in the lithium iron phosphate battery when the total power input is less than the power demand of the hydrogen production device (such as the electrolyzer), and adjust the electrolyzer power according to the wind and solar power generation and the economy of the grid power. The hybrid electrolyzer array 03 is composed of AEL (alkaline electrolyzer) and PEM (proton exchange membrane electrolyzer), which are coupled to the AC bus through power electronic equipment.

[0057] In an optional embodiment provided by the present disclosure, a mathematical model of an alkaline electrolytic cell is established. The working voltage of a single electrolytic cell is relatively low. A plurality of single electrolytic cells are connected in series to form a stack. At any working temperature, the volt-ampere characteristic of the stack is:

[0058]

[0059] Where: T el is the temperature of the electrolytic cell; el is the current of the electrolytic cell; r1 and r2 are the ohmic resistance parameters of the electrolyte; s1, s2, s3 are the electrode overvoltage coefficients; t1, t2, t3 are the electrolyte overvoltage coefficients; U rev is the reversible open circuit voltage; A el is the electrode area; N el U is the number of electrolytic cells connected in series; el Output voltage for a single electrolyzer.

[0060] According to Faraday's law, the hydrogen production rate of the electrolyzer depends on the current of the electrolyzer. The hydrogen production rate formula of the alkaline electrolyzer is:

[0061]

[0062] Where: z is the number of gas compressions; F is the Faraday constant; η(T el ,j) is the electrolysis efficiency, which changes with the current density and temperature; a i (i=1,2,3,4,5) is the Faraday efficiency coefficient; j el is the current density, and its value is I el / A el .

[0063] In an optional embodiment provided by the present disclosure, a mathematical model of a proton exchange membrane electrolyzer is established. The PEM electrolyzer voltage model is composed of an open circuit voltage, an activation overvoltage, and an ohmic overpotential. Equation 3 describes the expression of the total voltage of the electrolyzer:

[0064] V el =V ocv +V act +V ohm (3)

[0065] Among them, the open circuit voltage V ocv is the theoretical minimum voltage for electrolytic cell startup, expressed as:

[0066]

[0067] Where: E0 is the standard electromotive force; R is the ideal gas constant; z0 is the number of electron transfers in the reaction, which is 2; is the hydrogen partial pressure; is the partial pressure of oxygen; is the water activity between the anode and the electrolyte, which is taken as 1.

[0068] Activation overpotential V act The expression is:

[0069]

[0070] Where: α is the transfer coefficient; i is the current density; i0 is the exchange current density.

[0071] Ohmic overpotential V ohm Its value is related to the material properties of the components inside the electrolytic cell, and the specific expression is:

[0072]

[0073] Where: R ohm is the electron of the proton exchange membrane; Tm is the operating temperature, σ m is the resistivity of the proton exchange membrane, which depends on the properties of the membrane itself and the operating temperature. It can be obtained from the empirical formula:

[0074]

[0075] Where: m is the water content of the proton exchange membrane.

[0076] The hydrogen production efficiency formulas of the two types of electrolyzers are:

[0077]

[0078] Where ΔG is the Gibbs free energy; P el The power of hydrogen production by electrolyzer.

[0079] At present, the two water electrolysis hydrogen production technologies, mainly AEL and PEMEL, have become the mainstream of the development of the green hydrogen market. The working characteristics of the two types of electrolyzers are compared as shown in Table 1:

[0080] Table 1

[0081]

[0082] It can be seen from Table 1 that AEL has the characteristics of low cost and high reliability, while PEMEL has the advantages of wide range, long cycle and fast response. Suitable electrolyzers are selected to form hybrid electrolyzers under various complex working conditions to improve the flexible response capability of the hydrogen production system. Analysis shows that when the capacity configuration ratio of the hybrid electrolyzer array 03 is set to AEL:PEMEL=2:1, the system energy utilization efficiency and economy are most reasonable, and the wind power hydrogen production system 100 can be operated stably within the full power range. In addition, the present disclosure divides the hybrid electrolyzer array 03 into two groups: one group is composed of AEL, which is responsible for rated operation, and the other group is composed of PEMEL, which is responsible for adapting to fluctuating operation.

[0083] In this way, the present disclosure constructs a wind-hydrogen-storage integrated system by combining distributed wind power with a hybrid electrolyzer array 03 and a grid-type energy storage system, wherein the hybrid electrolyzer array 03 includes alkaline electrolyzers and proton exchange membrane electrolyzers with a capacity configuration ratio of 2:1, and is operated in groups according to rated operation and fluctuation states, so as to give full play to the advantages of electrolyzers in different operating groups, so as to realize a reasonable distribution of hydrogen production power of the hybrid electrolyzers in the wind power hydrogen production system 100.

[0084] Figure 2 The figure shows a control strategy block diagram of a grid-type energy storage system provided by an embodiment of the present disclosure. Please refer to Figure 1 and Figure 2In an optional embodiment provided by the present disclosure, the alkaline electrolyzer is configured to adopt direct power control, and at least one alkaline electrolyzer in the rated group is operated at a rated power P N Run, or, both stop running.

[0085] Specifically, the grid-type energy storage consists of a droop control strategy that simulates the operating mechanism of a synchronous generator and a lithium iron phosphate battery. In the wind power hydrogen production system 100, when the hydrogen production power cannot meet the demand, the hybrid electrolyzer array 03 may experience a large-scale shutdown state, which will cause inconsistent operating time of the electrolyzer. To solve this problem, the grid-type energy storage system can provide the necessary active power support for the hybrid electrolyzer to maximize the safe and stable operation of the wind power hydrogen production system 100. At the same time, when the wind power overflows, the surplus power can be absorbed in time to further improve the system's wind power absorption rate.

[0086] Figure 3 The figure shows an AEL control block diagram provided by the embodiment of the present disclosure, please refer to Figure 3 , the embodiment of the present disclosure formulates corresponding control strategies according to the operating characteristics of the alkaline electrolyzer. For example, in the AC / DC converter part of the alkaline electrolyzer, direct power control is adopted to ensure that the electrolyzer can continuously and stably consume its rated power. In the DC / DC converter part, the alkaline electrolyzer reference output power P elref With AEL rated terminal voltage U el Divide to generate the current reference value I elref and the actual current value I el After the difference is made, it is compared with the triangle wave through PI control to generate the pulse signal D of the Buck converter. el .

[0087] Figure 4 The figure shows an AEL hydrogen production efficiency and hydrogen production rate diagram provided by the embodiment of the present disclosure. Please refer to Figure 4 After applying the control strategy, the AEL hydrogen production rate at the rated state is 6.1 mol / s and the hydrogen production efficiency is 60%.

[0088] Figure 5 The figure shows a PEMEL control block diagram provided by the embodiment of the present disclosure, please refer to Figure 5 The disclosed embodiment formulates a corresponding control strategy for the operating characteristics of the proton exchange membrane electrolyzer. Since the PEM electrolyzer has good regulation characteristics, an additional power adjustment link is added to the PEM electrolyzer Buck converter control strategy, which can control the PEM electrolyzer to increase 20% P outside the normal operating range. eln The real-time output power is obtained according to the change of the current and voltage of the PEM electrolyzer, and then the fluctuating current is obtained through the power loop PI control after calculating with the reference power of the PEM electrolyzer, and then compared with the reference current value Ielref After the difference is made, the pulse control signal D of the Buck converter is generated through the current loop PI control el .

[0089] Figure 6 The figure shows a PEMEL hydrogen production efficiency and hydrogen production rate diagram provided by the embodiment of the present disclosure. Please refer to Figure 6 After applying the control strategy, when the hydrogen production power is low, the change of hydrogen production efficiency is more significant with the increase of power, and the maximum hydrogen production efficiency can reach 83%, and the corresponding maximum hydrogen production power is 0.45MW. However, with the further increase of power, the hydrogen production efficiency gradually decreases, and stabilizes at 62% after reaching the maximum operating power of 3MW. At the same time, the hydrogen production rate gradually increases from the initial 3.1mol / s to 5.7mol / s.

[0090] In this way, by analyzing the operating characteristics of the AEL electrolyzer and the PEMEL electrolyzer, corresponding control strategies are formulated respectively. The hydrogen production rate of the AEL electrolyzer in the rated state after optimized control is 6.1 mol / s, and the hydrogen production efficiency is 60%. The maximum hydrogen production efficiency of the PEMEL electrolyzer after optimized control can reach 83%, and the maximum hydrogen production rate can reach 5.7 mol / s. That is, by operating the AEL electrolyzer in the hybrid electrolyzer array 03 at the rated state, the rated group stable hydrogen production rate and hydrogen production efficiency can be obtained. By operating the PEMEL electrolyzer in the hybrid electrolyzer array 03 in a fluctuating state, according to the characteristics of the distributed wind power unit 01, combined with the fluctuating wind power, the efficiency of the hybrid electrolyzer array 03 and the efficiency of the wind power hydrogen production system 100 can be maximized.

[0091] Figure 7 FIG. 1 is a schematic diagram of a group rotation control strategy provided by an embodiment of the present disclosure, please refer to Figure 7 In an optional embodiment provided by the present disclosure, the proton exchange membrane electrolyzer is configured to adopt additional power adjustment, and the proton exchange membrane electrolyzers in the fluctuation group operate with fluctuating power, wherein the minimum operating power P of the proton exchange membrane electrolyzer is min =20%P N , maximum operating power P max =120%P N , standby power P s =3%P N .

[0092] Specifically, the group rotation control strategy aims to reasonably allocate the start and stop states and the power consumption of each electrolyzer. The hybrid electrolyzer group rotation control strategy proposed in this disclosure is to divide the hybrid electrolyzer into two groups: one group is composed of AELs, which are responsible for rated operation; the other group is composed of PEMELs, which are responsible for adapting to fluctuating operation. The schematic diagram of the group rotation control strategy is shown in Figure 7 As shown, through this group rotation, the operating status of the hybrid electrolyzer array 03 can be managed more effectively, the absorption power can be adjusted reasonably, and the safe and stable operation of the wind power hydrogen production system 100 can be guaranteed to the greatest extent.

[0093] The present disclosure proposes a mixed integer segmented model algorithm based on the hybrid electrolyzer group rotation control strategy, sets the hydrogen production, operating time and start-stop times as optimization objects, and uses the operating characteristics and power allocation as model constraints. Due to the start-stop characteristics of the alkaline electrolyzer, the rated group enters the pre-start state whenever it reaches the starting power. The fluctuation group (fluctuation state, standby state, overload state, shutdown state) and the rated group (working state, shutdown state) are used as integer variables, that is, the operating state of each electrolyzer is controlled in the form of the output power per unit value. For example, the rated group consists of n alkaline electrolyzers, numbered P r1 , P r2 , P r3 …P rn The wave group consists of m PEM electrolyzers, numbered P f1 , P f2 …P fm ; Rated power is P N , wind power is P w ; The power of hybrid electrolyzer array 03 is P el =(1-20%)P w , the ideal minimum safe operating power P of the PEM electrolyzer min =20%P N , PEM electrolyzer maximum operating power (overload state) P max =120%P N , PEM electrolyzer standby power (standby state) P s =3%P N , the power of the energy storage system P b , the rotation time is T.

[0094] In this way, according to the wide range of power fluctuations in the distributed wind power unit 01, the rated power P of the AEL in the rated group N The fluctuation state power of PEMEL in the fluctuation group is 20%P N Up to 120%P N , Standby power P s =3%P N Combined with each other, it ensures the coordinated operation of AEL and PEMEL, gives full play to the operating characteristics of each equipment, and realizes the reasonable allocation of hydrogen production power.

[0095] Figure 8 The figure shows a mixed integer segmentation model flow chart provided by the embodiment of the present disclosure, please refer to Figure 8The present disclosure provides an operation strategy of a wind power hydrogen production system 100, which is applied in the wind power hydrogen production system 100 as described above, and includes:

[0096] When the power that the hybrid electrolyzer array 03 needs to absorb is (m-1)P S +nP N +P min ≤P el <nP N +(m-1)P S +P max , it is determined that the hybrid electrolytic cell array 03 is in rated working condition, and at this time, the hybrid electrolytic cell array 03 operates in mode 1;

[0097] When the power that the hybrid electrolyzer array 03 needs to absorb is (mk)P S +nP N +kP min ≤P el <nP N +(mk)P S +kP max , it is determined that the hybrid electrolytic cell array 03 is in an overload condition, and at this time the hybrid electrolytic cell array 03 operates in mode 2;

[0098] When the power that the hybrid electrolyzer array 03 needs to absorb is P el ≥nP N +P S +(m-1)P max , it is determined that the hybrid electrolytic cell array 03 is in an overload condition, and at this time the hybrid electrolytic cell array 03 operates in mode three;

[0099] When the power that the hybrid electrolyzer array 03 needs to absorb is (m-1)P S +P N +P min ≤P el <xP N +(m-1)P S +P max , it is determined that the hybrid electrolytic cell array 03 is in an underload condition, and at this time, the hybrid electrolytic cell array 03 operates in mode four;

[0100] When the power that the hybrid electrolyzer array 03 needs to absorb is (m-1)P S +P min ≤P el <(m-1)P S +P max , it is determined that the hybrid electrolytic cell array 03 is in an underload condition, and at this time, the hybrid electrolytic cell array 03 operates in mode five;

[0101] When the power that the hybrid electrolyzer array 03 needs to absorb is 0<P el<(m-1)P S +P min , it is determined that the hybrid electrolytic cell array 03 is in an underload condition, and at this time, the hybrid electrolytic cell array 03 operates in mode six;

[0102] Among them, the real-time measured wind power of the system is P w , the power of the hybrid electrolyzer array 03 is P el =(1-20%)P w ; The number of the alkaline electrolytic cell in the rated group is P r1 , P r2 , P r3 …P rn ; The number of the proton exchange membrane electrolyzer in the wave group is P f1 , P f2 …P fm .

[0103] It should be noted that the power of the hybrid electrolytic cell array 03 here refers to the power that the hybrid electrolytic cell array 03 can absorb.

[0104] For more information, see Figure 8 , taking into account the characteristics of AEL and PEMEL, as well as the wide range of power fluctuations in the wind power hydrogen production system 100, the present disclosure proposes an operation strategy for the wind power hydrogen production system 100, which aims to perform multi-time scale fuzzy segmented grouping rotation on the hybrid electrolyzer array 03. The strategy divides the operating state of the hybrid electrolyzer into three scenarios, namely rated operating conditions, overload conditions, and underload conditions. According to the power that the hybrid electrolyzer array 03 can absorb under different operating conditions, the hybrid electrolyzer is divided into six operating modes, and the start and stop time and absorbed power of each electrolyzer in different operating modes are controlled by a mixed integer segmented model.

[0105] Under rated conditions, the hybrid electrolytic cell array 03 operates in mode 1. At this time, the N alkaline electrolytic cells in the rated group of the hybrid electrolytic cell array 03 operate at a rated power P N Operation, only one of the M proton exchange membrane electrolyzers in the fluctuation group is in operation, and the operating power of the operating proton exchange membrane electrolyzer is at the ideal minimum safe operating power 20% P N With maximum operating power 120% P N The remaining proton exchange membrane electrolyzers are in standby mode, and the power of the hybrid electrolyzer array 03 is (m-1)P S +nP N +P min ≤P el <nP N +(m-1)P S +P max .

[0106] Under overload conditions, the hybrid electrolyzer array 03 can operate in Mode 2 or Mode 3. Under overload conditions, all the rated groups in the hybrid electrolyzer array 03 are put into operation and operate at the rated power P N The fluctuating group has at least one proton exchange membrane electrolyzer operating at 120%P of the maximum operating power N In Mode 2, k proton exchange membrane electrolyzers operate at fluctuating power, 0 < k < m, and k is a positive integer. At this time, the power of the hybrid electrolyzer array 03 is (m - k)P S + nP N + kP min ≤ P el < nP N +(m - k)P S + kP max ;In Mode 3, m - 1 proton exchange membrane electrolyzers operate at 120%P of the maximum operating power N One proton exchange membrane electrolyzer is left on standby for rotation. At this time, the power of the hybrid electrolyzer array 03 is P el ≥ nP N + P S +(m - 1)P max 。

[0107] Under underload conditions, the hybrid electrolyzer array 03 can operate in Mode 4, Mode 5, and Mode 6. Under underload conditions, at least one alkaline electrolyzer in the rated group is in a shutdown state, and at least one proton exchange membrane electrolyzer in the fluctuating group operates at fluctuating power; in Mode 4, only one proton exchange membrane electrolyzer in the fluctuating group operates at fluctuating power, and the operating power is between 20%P of the ideal minimum safe operating power N and 120%P of the maximum operating power N The rest of the proton exchange membrane electrolyzers are in standby rotation state. At least one alkaline electrolyzer in the rated group operates at rated power, and the rest of the alkaline electrolyzers are in shutdown state. At this time, the power of the hybrid electrolyzer array 03 is (m - 1)P S + P N + P min ≤ P el < xP N +(m - 1)P S + P max ;In Mode 5, all the electrolyzers in the rated group are shut down, and only one proton exchange membrane electrolyzer in the fluctuating group operates at fluctuating power. The operating power is between 20%P of the ideal minimum safe operating power N and 120%P of the maximum operating power N The rest of the electrolyzers are in standby rotation state. At this time, the power of the hybrid electrolyzer array 03 is (m - 1)P S + P min ≤ P el <(m - 1)P S+P max In mode 6, all rated groups are shut down, and only one proton exchange membrane electrolyzer in the fluctuation group is operating at a power lower than the ideal minimum safe operating power of 20% P N The remaining proton exchange membrane electrolyzers are in standby rotation state. At this time, the power of the hybrid electrolyzer array 03 is 0<P el <(m-1)P S +P min .

[0108] In this way, through the mixed integer segmented model algorithm proposed in the present invention, an operation strategy of the wind power hydrogen production system 100 is formulated, and the hybrid electrolyzer array 03 under three different operating conditions, namely rated condition, overload condition, and underload condition, is divided into six operating modes. The power of the hybrid electrolyzer array 03 in each mode can adapt to the power fluctuation changes of the distributed wind power unit 01, improve the adaptability of the hybrid electrolyzer to the fluctuating power source, and ensure the reasonable distribution of power to the greatest extent.

[0109] Please continue to refer to Figure 8 In an optional embodiment provided by the present disclosure, in mode 1, all alkaline electrolyzers in the rated group are in operation, only one proton exchange membrane electrolyzer in the fluctuation group is in operation, and m-1 proton exchange membrane electrolyzers are on standby for rotation; the mixed integer segmented model outputs instructions:

[0110]

[0111] Specifically, the rated power of the alkaline electrolyzers in the rated group and the proton exchange membrane electrolyzers in the wave group in the hybrid electrolyzer array 03 are both P N , the rated group consists of n alkaline electrolytic cells, numbered P r1 , P r2 , P r3 …P rn The wave group consists of m PEM electrolyzers, numbered P f1 , P f2 …P fm ; Ideal minimum safe operating power P of PEM electrolyzer min =20%P N , PEM electrolyzer maximum operating power P max =120%P N , PEM electrolyzer standby power P s =3%P N , the rotation time is T.

[0112] When the power consumed by the hybrid electrolyzer array 03 is (m-1)P S +nP N +P min ≤P el <nP N +(m-1)PS +P max , the hybrid electrolyzer array 03 is in rated working condition, the hybrid electrolyzer array 03 operates in mode 1, in which the n alkaline electrolyzers in the rated group of the hybrid electrolyzer array 03 operate at rated power P N Run, that is, P r1 =P r2 =P r3 …=P rn =P N ; The number in the wave group is P f2 …P fm The proton exchange membrane electrolyzer is based on P f2 =…=P fm =P s =3%P N The standby power is waiting for rotation, and the number in the fluctuation group is P f1 The proton exchange membrane electrolyzer is based on P el -nP N -(m-1)P s In this way, the hybrid electrolyzer array 03 in mode 1 can be operated at fluctuating power when the rated group is operating at full rated power, and a proton exchange membrane electrolyzer in the fluctuation group can be operated at fluctuating power to adapt to the power fluctuation changes of the distributed wind power unit 01, and the remaining m-1 proton exchange membrane electrolyzers in the fluctuation group can be put on standby for rotation, which is beneficial to the reasonable distribution of power and prolonging the service life of the proton exchange membrane electrolyzers in the fluctuation group.

[0113] It should be noted that the rated group and the fluctuation group in the mixed electrolytic cell array 03 can be numbered in sequence along the arrangement order of the electrolytic cells, or can be numbered in reverse order along the arrangement order, or can be numbered from the middle position of the electrolytic cell arrangement. The present disclosure does not impose specific restrictions on the numbering method of the electrolytic cells, which is subject to actual needs.

[0114] In an optional embodiment provided by the present disclosure, in mode 2, all alkaline electrolyzers in the rated group are in operation; the fluctuation group has k proton exchange membrane electrolyzers participating in the average sharing of the fluctuation power, and (mk) units participating in the standby rotation; the mixed integer segmented model output instruction is:

[0115]

[0116] After the rotation time T is reached,

[0117]

[0118] Specifically, when the power consumed by the hybrid electrolyzer array 03 is (mk)P S +nP N +kP min ≤P el<nP N +(mk)P S +kP max , the hybrid electrolyzer array 03 is in an overload condition, and the hybrid electrolyzer array 03 operates in mode 2. In mode 2, the n alkaline electrolyzers in the rated group of the hybrid electrolyzer array 03 operate at the rated power PN, that is, P r1 =P r2 =P r3 …=P rn =P N There are k PEM electrolyzers in the fluctuation group that participate in the average sharing of the fluctuation power, where the upward rounding function is used Find, that is, P f1 …P fk These k PEM electrolyzers are all based on (P el -nP N ) / k fluctuating power operation, (mk) proton exchange membrane electrolyzers participate in standby rotation, that is, (mk) PEM electrolyzers operate at P S =3%P N The standby power is waiting for rotation.

[0119] After the rotation time T is reached, the n alkaline electrolyzers in the rated group still operate at the rated power P N Run, that is, P r1 =P r2 =P r3 …=P rn =P N ; P in the fluctuation group f1 …P fk The k PEM electrolyzers are s =3%P N The power standby, and the P f(2k+1) …P fm PEM electrolyzer with P s =3%P N Power standby; P f(k+1) …P f2k These k PEM electrolyzers are all equipped with P f(k+1) =…=P f2k =(P el -nP N ) / k fluctuating power operation.

[0120] In this way, the hybrid electrolyzer array 03 in mode 2 can be operated at fluctuating power in combination with the k proton exchange membrane electrolyzers in the fluctuation group while the rated group is operating at full rated power, so as to adapt to the power fluctuation changes of the distributed wind power unit 01, and the remaining mk proton exchange membrane electrolyzers in the fluctuation group can be put on standby for rotation. This mode of operation can achieve the reasonable equal distribution of hydrogen production power and time by the hybrid electrolyzer array 03.

[0121] In an optional embodiment provided by the present disclosure, in mode three, all alkaline electrolyzers in the rated group are in operation; all proton exchange membrane electrolyzers in the fluctuation group are also in operation, operating in a rated or overloaded state, and excess power is absorbed by the energy storage system; the mixed integer segmented model output instruction is:

[0122]

[0123] Specifically, when the power consumed by the hybrid electrolyzer array 03 is P el ≥nP N +P S +(m-1)P max , the hybrid electrolyzer array 03 is in overload condition, and the hybrid electrolyzer array 03 operates in mode 3. In mode 3, the n alkaline electrolyzers in the rated group of the hybrid electrolyzer array 03 operate at rated power P N Run, that is, P r1 =P r2 =P r3 …=P rn =P N The proton exchange membrane electrolyzers in the wave group are all put into operation, and the operating power is the rated power P N Or maximum operating power P max =120%P N , that is, the Pth f1 …P fm The operating power of these m proton exchange membrane electrolyzers is (P el -nP N ) / m, the excess power is absorbed by the energy storage unit 02, and the power absorbed by the energy storage unit 02 is P b =P el -nP N -mP max After the rotation time T is reached, the hybrid electrolyzer array 03 can reasonably share the hydrogen production power and time by continuing to operate according to formula (12).

[0124] In this way, the hybrid electrolyzer array 03 in mode three can be operated at rated power or maximum operating power in combination with all proton exchange membrane electrolyzers in the fluctuation group while the rated group is operating at full rated power. The excess power is absorbed by the energy storage unit 02, and the remaining power can be stored in the energy storage unit 02 while maximizing the hydrogen production efficiency, providing backup power when the hydrogen production power cannot meet the demand, reducing the downtime of the hybrid electrolyzer array 03, and improving the safety and stability of the wind power hydrogen production system 100.

[0125] In an optional embodiment provided by the present disclosure, in mode 4, only one proton exchange membrane electrolyzer in the fluctuation group participates in operation, and the remaining m-1 units are on standby rotation; the rated group has x alkaline electrolyzers working in the rated state, and nx units are in the shutdown state; the mixed integer segmented model output instruction is:

[0126]

[0127] After the rotation time T is reached,

[0128]

[0129] Specifically, when the power consumed by the hybrid electrolyzer array 03 is (m-1)P S +P N +P min ≤P el <xP N +(m-1)P S +P max , the hybrid electrolyzer array 03 is in underload condition, the hybrid electrolyzer array 03 operates in mode 4, in which the x alkaline electrolyzers of the rated group in the hybrid electrolyzer array 03 operate in the rated state, where the rounding function is used to obtain That is, the operating power of these x alkaline electrolyzers is P r1 =P r2 =P r3 …=P rx =P N ; The remaining nx alkaline electrolyzers are in shutdown state, with a power of P r(x+1) =…=P rn =0, waiting to participate in the rotation in hot standby state. Only one PEM electrolyzer in the fluctuation group participates in the average sharing of fluctuation power, and the operating power of this PEM electrolyzer is P f1 =P el -xP N -(m-1)P s The remaining m-1 PEM electrolyzers are P s =3%P N of power standby.

[0130] After the rotation time T is reached, the Pth r(x+1) , P r(x+2) …P r(x+x) These x alkaline electrolyzers are working at rated conditions. r1 …P rx 、P r(2x+1) …P rn These nx alkaline electrolyzers are in shutdown state. Accordingly, the fluctuation group rotates to the Pth f2 PEM electrolyzer with P el-xP N -(m-1)P s The remaining P f1 , P f3 …P fm This m-1 PEM electrolyzer is based on P s =3%P N of power standby.

[0131] In this way, the hybrid electrolyzer array 03 in mode four can operate at rated power with x alkaline electrolyzers in the rated group and at fluctuating power with one proton exchange membrane electrolyzer in the fluctuating group, so as to adapt to the low power of the distributed wind power unit 01 in an underloaded state and put the remaining electrolyzers in the rated group and the fluctuating group on standby for rotation. This mode of operation can realize the reasonable distribution of hydrogen production power and time by the hybrid electrolyzer array 03.

[0132] In an optional embodiment provided by the present disclosure, in mode 5, all alkaline electrolyzers in the rated group stop running; only one proton exchange membrane electrolyzer in the fluctuation group participates in the fluctuation operation, and the remaining m-1 are on standby for rotation; the mixed integer segmented model output instruction is:

[0133]

[0134] Specifically, when the power consumed by the hybrid electrolyzer array 03 is (m-1)P S +P min ≤P el <(m-1)P S +P max , the hybrid electrolyzer array 03 is in an underload condition, and the hybrid electrolyzer array 03 operates in mode five. In mode five, all alkaline electrolyzers in the rated group of the hybrid electrolyzer array 03 stop operating, that is, P r1 =P r2 =P r3 …=P rn =0; only one PEM electrolyzer in the fluctuation group participates in the average sharing of fluctuation power, and the operating power of this PEM electrolyzer is P f1 =P el -(m-1)P s The remaining m-1 PEM electrolyzers are P s =3%P N of power standby.

[0135] After the rotation time T is reached, the fluctuation group can rotate according to this mode to achieve balanced distribution of the fluctuation power in the hybrid electrolytic cell array 03.

[0136] In this way, the hybrid electrolyzer array 03 in mode five can operate at fluctuating power in conjunction with a proton exchange membrane electrolyzer in the fluctuation group when all rated groups stop operating, adapt to the low power of the distributed wind power unit 01 in an underloaded state, and put the remaining electrolyzers in the fluctuation group on standby for rotation to maximize hydrogen production efficiency.

[0137] In an optional embodiment provided by the present disclosure, in mode six, at least one proton exchange membrane electrolyzer in the fluctuation group is maintained in the lowest ideal operating state, the others enter the standby state, the alkaline electrolyzer in the rated group stops operating, and the output instruction of the mixed integer segmented model is:

[0138]

[0139] Specifically, in mode 6, the power that the hybrid electrolyzer array 03 needs to absorb is 0<P el <(m-1)P S +P min In order to maintain the flexibility and reliability of the hybrid electrolyzer array 03, the lithium iron phosphate battery in the energy storage unit 02 is used to release a certain amount of power to ensure that at least one PEM electrolyzer belonging to the fluctuation group can maintain the lowest ideal operating state. The operating power of the PEM electrolyzer is P min =20%P N , the remaining PEM electrolyzers will enter standby mode, that is, P f2 =…=P fm =P s , and the rated group stops running, that is, P r1 =P r2 =P r3 …=P rn =0, at this time the power released by energy storage unit 02 is P b =P min +(m-1)P s -P el In this way, when the power output by the distributed wind power unit 01 does not meet the demand for hydrogen production power, the lithium iron phosphate battery in the energy storage unit 02 can provide necessary active support for the hybrid electrolyzer array 03, ensuring the safe and stable operation of the wind power hydrogen production system 100 and reducing the risk of downtime.

[0140] In order to verify the effectiveness and applicability of the proposed hybrid electrolyzer group rotation control strategy, the example uses a typical daily data sample of an actual distributed wind farm in a certain area of ​​Inner Mongolia. The selected input sample has a wide range of fluctuating power coverage, which has a more comprehensive verification effect on the proposed hybrid electrolyzer rotation control strategy. The parameters of each unit of the wind power hydrogen production system 100 are shown in Table 2:

[0141] Table 2

[0142]

[0143] Fig. 9 The figure shows a typical wind speed and output torque, speed, voltage and current diagram provided by the embodiment of the present disclosure. Please refer to Fig. 9 According to the static characteristics and rotation strategies of the above electrolyzers, the switching cycle, i.e. the rotation time, is set to T = 10min, which ensures the maximum power consumption while avoiding the long-term fluctuation of the PEM electrolyzer. A typical wind speed sample of 100min is selected to conduct a detailed operation status analysis of the hybrid electrolyzer hydrogen production system.

[0144] Fig.10 The figure shows the overall operation of each unit of a wind power hydrogen production system provided by the embodiment of the present disclosure. Please refer to Fig.10 , simulated in MATLAB / SIMULINK simulation platform, analyzed the operation status of each unit, and verified the stability and flexibility of the hybrid electrolytic cell group rotation control strategy based on fuzzy segmentation. Fig.10 It can be seen that the total power curve of the hybrid electrolyzer array 03 is consistent with the trend of the wind power curve, that is, the operation strategy of the wind power hydrogen production system 100 provided in the present disclosure can achieve accurate tracking of wind power.

[0145] Combination Fig.10 It can be concluded that: in the first stage, as the wind speed is cut in and the wind turbine starts to work, due to the initial wind speed of about 8.2m / s, the wind power meets the grid-connected power, and the remaining hydrogen production power cannot meet the minimum safe operating power of the electrolyzer array. Fig.11 FIG. 1 is a schematic diagram showing the operation of each unit of a hybrid electrolyzer provided in an embodiment of the present disclosure. Fig.12 The figure shows a schematic diagram of the output of an energy storage unit 02 provided in an embodiment of the present disclosure, Fig.12 It can be seen that: at 3 minutes, the energy storage system starts to operate, releasing a maximum of 0.5MW of active power. Through mode six, the fluctuation group electrolyzers are controlled to operate in the minimum operating state and standby state respectively, meeting the minimum safe operating conditions of the electrolyzer array. As the wind speed increases to 10m / s, the system operation enters stage II, and the real-time calculated hydrogen production power is obtained. According to the power fuzzy segmentation model, it is determined that the system is working under underload conditions. The formula of mode four is used to determine that the rated group has 2 alkaline electrolyzers working in the rated state. Fig.10 It can be seen that the rated group power value is stable at 5MW, the fluctuating power is absorbed by one PEM electrolyzer, and the other is on standby. When the first rotation time of 10 minutes is reached, the switch is made according to the rotation control strategy. Among them, the grid-connected power will have a certain peak value with the switching of the rated group at about 20 minutes. Fig.11It can be concluded that the output of each electrolyzer is due to the instantaneous increase in current when the No. 1 and No. 3 alkaline electrolyzers participate in the rotation on the basis of the unchanged total hydrogen production power.

[0146] As the wind speed increases, the system enters stage III after running for 3T. The formula of mode 1 shows that all the electrolyzers in the rated group of the electrolyzer array are in operation. Since AEL has a certain delay, electrolyzer No. 1 only participates in the consumption at 32 minutes; only one PEM electrolyzer in the fluctuation group participates in the operation, and the fluctuation power increases from 0.7MW to 1.4MW in 32 minutes, maximizing the dynamic response capability of the PEM electrolyzer, and another PEMEL is on standby for rotation. Stage IV simulates a scene with large changes in wind speed, with the wind speed decreasing from 11.5m / s to 8.3m / s. The mixed integer segmented model responds to the real-time power changes. At this time, the system transitions from mode 4 to mode 6. It can be seen that the rated group of electrolyzers is reduced from all operation to all shutdown operation. At the same time, in order to ensure the safety of the electrolyzer array, the energy storage system starts working at 53 minutes to ensure that the hybrid electrolyzer remains in the lowest safe operating state. As the wind speed recovers, the system briefly enters mode 4 in stage V, and then the wind speed increases to 12m / s, and the power reaches the overload condition segmentation interval. It can be seen from mode 2 that at this time, the hybrid electrolyzer array 03 fully participates in absorbing wind power, and the two PEM electrolyzers jointly participate in absorbing fluctuating power, with a peak absorption capacity of 1.6MW. The wind speed suddenly decreases in stage VII, and the mixed integer segmented model responds to the real-time changing power. At this time, using the formula of mode 4, it can be seen that the rated group of electrolyzers is reduced from all operation to only one rated operation. At about 85 minutes, as the wind speed enters stage VIII, the system operates in mode 5. It can be seen from formula 15 that at this time, the power can no longer meet the minimum operating conditions of the rated group, and the hydrogen production power is all absorbed by a fluctuating group PEM electrolyzer. As the wind speed further decreases, in stage IX, simulating special operating mode 6, the wind speed drops to 8.2m / s. At this time, the power cannot meet the minimum safe operating limit of 0.5MW specified by PEM. Therefore, at 96 minutes, the energy storage system starts to work and provides 0.3MW of active power output. Under the simple rotation strategy, it is inevitable that a certain amount of wind curtailment will occur.

[0147] In order to improve the wind power abandonment phenomenon and increase the system resource utilization rate, the wind power hydrogen production system 100 provided in the embodiment of the present disclosure is equipped with a 3MW grid-type energy storage unit 02. Fig.12 As shown, the energy storage system takes the entire time period into consideration to ensure the safety of the hybrid electrolyzer array 03, improve the system's dynamic response capability while ensuring hydrogen production efficiency, and further improve the wind hydrogen system's absorption rate.

[0148] From the above, it can be seen that under typical daily wind speed samples, the mixed integer fuzzy piecewise model can effectively adapt to a variety of complex actual working conditions. The grouped hybrid electrolyzer array can respond well to the operating status and power demand assigned by the model, verifying the feasibility and reliability of the hybrid electrolyzer group rotation control strategy.

[0149] Fig.13 The figure shows the operation status of each electrolytic cell under a simple equal distribution strategy provided by the embodiment of the present disclosure. Please refer to Fig.13 , under the same typical wind speed, the operating curves of electrolyzers with different numbers have obvious differences. The electrolyzers with earlier numbers have longer operating time and more switching times. The electrolyzers with later numbers are in a non-operating state for a longer time, and the operating state and power distribution are unreasonable. If it runs for a long time, the degree of damage of electrolyzers with different numbers will be very different, and the array consistency is poor. In actual projects, it not only reduces the overall operating life, but also leads to an increase in the number of safety inspections and increases the cost of hydrogen production. In addition, the electrolyzer will switch between different operating states, and may even be in an overload state for a long time. The power distribution is unreasonable, which makes the short board effect more obvious.

[0150] Fig.14 The figure shows a comparison and analysis diagram of a group rotation control strategy based on fuzzy segmentation and a simple time averaging strategy of a single PEM provided by an embodiment of the present disclosure. Please refer to Fig.14 In the same scenario, in terms of operating time, the operating time of each group of electrolyzers under the disclosed operating strategy is distributed in 4 to 5 operating cycles, and the overall time distribution of the hybrid electrolyzer array 03 is relatively balanced; under the simple time averaging strategy, the operating time of PEM electrolyzer No. 2 accounts for as high as 72.25%, while that of PEM electrolyzer No. 6 is only 10.5%. The distribution and use are unreasonable, resulting in a reduction in the overall operating life of the PEM electrolyzer array. In terms of the proportion of start-stop times, the start-stop times of each group of electrolyzers under the disclosed operating strategy are relatively balanced, while under the simple time averaging strategy, it can be clearly seen that the start-stop times of electrolyzer No. 1 are much higher than those of other electrolyzers, and the electrolyzer life has a significant shortcoming, affecting the overall life of the electrolyzer array. In terms of hydrogen production efficiency, the overall hydrogen production efficiency of the hybrid electrolyzer array 03 is not significantly better than that of the single PEM electrolyzer array, but under the same typical scenario cycle, the total hydrogen production in the simple time-averaged mode is 0.13t, while the hydrogen production in the mixed integer segmented model can reach 0.151t, an increase of 16.2% in total hydrogen production. Through reasonable power allocation, the maximum utilization of hydrogen production power is achieved. At the same time, while the hydrogen production volume increases, the cost of hydrogen production by the hybrid electrolyzer is reduced by 13.8%.

[0151] In summary, the present disclosure provides a wind power hydrogen production system and operation strategy, including: a distributed wind power unit, a hybrid electrolyzer array, an energy storage unit, and an AC power grid; the output end of the distributed wind power unit is connected to the wind power collection bus, the AC power grid is connected in series with one end of the transformer, the other end of the transformer is connected to the wind power collection bus, the energy storage unit is connected to the wind power collection bus, and the hybrid electrolyzer array is connected to the wind power collection bus; by controlling the start and stop, operation state and power distribution of each electrolyzer unit through a mixed integer segmented model, the following conclusions are drawn: Compared with the simulation of the simple time-sharing control strategy of equal capacity, the group rotation control strategy proposed in the present disclosure makes the operation of the hybrid electrolyzer The operation time and the number of starts and stops are more balanced, the hydrogen production is increased by 16.2%, and the cost is reduced by 13.8%; the mixed integer segmentation algorithm ensures that the hybrid electrolyzer makes adaptive adjustments between groups and within groups with power fluctuations, improves the flexible consumption of wind power in typical power fluctuation scenarios, and improves the dynamic coupling of wind power hydrogen production systems under multiple time scales; the hybrid electrolyzer group rotation control strategy proposed in the present disclosure gives full play to the operating characteristics and power regulation characteristics of each electrolyzer group, ensures the state consistency between the electrolyzer arrays, improves the adaptive response capability of the hydrogen production system, and gives full play to the role advantages of electrolyzers in different operating groups, so as to realize the reasonable distribution of hydrogen production power of hybrid electrolyzers in wind power hydrogen production systems. By analyzing the operating characteristics of AEL electrolyzers and PEMEL electrolyzers, corresponding control strategies are formulated respectively. The hydrogen production rate of the AEL electrolyzer in the rated state after optimized control is 6.1 mol / s, and the hydrogen production efficiency is 60%. The maximum hydrogen production efficiency of the PEMEL electrolyzer after optimized control can reach 83%, and the maximum hydrogen production rate can reach 5.7 mol / s. According to the wide range of power fluctuations in distributed wind power units, the rated power P of AEL in the rated group is N The fluctuation state power of PEMEL in the fluctuation group is 20%P N Up to 120%P N , Standby power P s =3%P N Combined with each other, it ensures the coordinated operation of AEL and PEMEL, gives full play to the operating characteristics of each device, and realizes the reasonable allocation of hydrogen production power. The proposed mixed integer segmented model algorithm formulates the operation strategy of the wind power hydrogen production system, divides the hybrid electrolyzer array under three different operating conditions, namely rated condition, overload condition, and underload condition, into six operating modes. The power of the hybrid electrolyzer array in each mode can adapt to the power fluctuation of the distributed wind power unit, improve the adaptability of the hybrid electrolyzer to the fluctuating power source, and ensure the reasonable distribution of power to the greatest extent.

[0152] The above description is only a specific embodiment of the present disclosure, so that those skilled in the art can understand or implement the present disclosure. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined in the present disclosure can be implemented in other embodiments without departing from the spirit or scope of the present disclosure. Therefore, the present disclosure will not be limited to these embodiments described in the present disclosure, but will conform to the widest scope consistent with the principles and novel features disclosed in the present disclosure.

Claims

1. A wind power hydrogen production system, characterized in that: include: Distributed wind power unit, hybrid electrolyzer array, energy storage unit, AC power grid; the output end of the distributed wind power unit is connected to the wind power collection bus, the AC power grid is connected in series with one end of the transformer, the other end of the transformer is connected to the wind power collection bus, the energy storage unit is connected to the wind power collection bus, and the hybrid electrolyzer array is connected to the wind power collection bus; The capacity configuration ratio of the alkaline electrolyzer to the proton exchange membrane electrolyzer in the hybrid electrolyzer array is 2:1; The hybrid electrolyzer array includes a rated group and a fluctuation group, wherein the rated group includes n alkaline electrolyzers; the fluctuation group includes m proton exchange membrane electrolyzers, where n is greater than or equal to 1 and is an integer, and m is greater than or equal to 1 and is an integer; the rated power of the electrolyzers in the hybrid electrolyzer array is P N .

2. The wind power hydrogen production system according to claim 1, characterized in that: The alkaline electrolysis cell is configured to adopt direct power control, and at least one alkaline electrolysis cell in the rated group is controlled at a rated power P N Operation, or, all alkaline electrolyzers are stopped.

3. The wind power hydrogen production system according to claim 1, characterized in that: The proton exchange membrane electrolyzer is configured to adopt additional power adjustment, and the proton exchange membrane electrolyzers in the fluctuation group operate with fluctuating power, wherein the minimum operating power P of the proton exchange membrane electrolyzer is min =20%P N , maximum operating power P max =120%P N , standby power P s =3%P N .

4. A wind power hydrogen production system operation strategy, characterized in that: The method is applied in the wind power hydrogen production system as claimed in any one of claims 1 to 3, comprising: When the power consumed by the hybrid electrolyzer array is (m-1)P S +nP N +P min ≤P el <nP N +(m-1)P S +P max , it is determined that the hybrid electrolyzer array is in rated working condition, and at this time the hybrid electrolyzer array operates in mode one; When the power consumed by the hybrid electrolyzer is (mk)P S +nP N +kP min ≤P el <nP N +(mk)P S +kP max , it is determined that the hybrid electrolyzer array is in an overload condition, and at this time the hybrid electrolyzer array operates in mode 2; When the power required to be absorbed by the hybrid electrolyzer array is P el ≥nP N +P S +(m-1)P max , it is judged that the hybrid electrolyzer array is in an overload condition, and at this time the hybrid electrolyzer array operates in mode three; When the power that the hybrid electrolyzer needs to absorb is (m-1)P S +P N +P min ≤P el <xP N +(m-1)P S +P max , it is judged that the hybrid electrolyzer array is in an underload condition, and at this time the hybrid electrolyzer array operates in mode four; When the power that the hybrid electrolyzer array needs to absorb is (m-1)P S +P min ≤P el <(m-1)P S +P max , it is judged that the hybrid electrolyzer array is in an underload condition, and at this time the hybrid electrolyzer array operates in mode five; When the power that the hybrid electrolyzer array needs to absorb is 0<P el <(m-1)P S +P min , it is determined that the hybrid electrolyzer array is in an underload condition, and at this time the hybrid electrolyzer array operates in mode six; Among them, the real-time measured wind power of the system is P w , the power of the hybrid electrolyzer array is P el =(1-20%)P w , the power of the energy storage unit is P b The alkaline electrolytic cell in the rated group is numbered P r1 , P r2 , P r3 …P rn The proton exchange membrane electrolyzer in the fluctuation group is numbered P f1 , P f2 …P fm .

5. The wind power hydrogen production system operation strategy according to claim 4, characterized in that: In the first mode, all alkaline electrolyzers in the rated group are in operation, only one proton exchange membrane electrolyzer in the fluctuation group is in operation, and m-1 proton exchange membrane electrolyzers are on standby for rotation; the mixed integer segmented model outputs the following instructions:

6. The wind power hydrogen production system operation strategy according to claim 4, characterized in that: In the second mode, all alkaline electrolyzers in the rated group are in operation; k proton exchange membrane electrolyzers in the fluctuation group participate in the average sharing of the fluctuation power, and (mk) units participate in the standby rotation; the mixed integer segmented model output instruction is: After the rotation time T is reached, 7. The wind power hydrogen production system operation strategy according to claim 4, characterized in that: In the third mode, all alkaline electrolyzers in the rated group are in operation; all proton exchange membrane electrolyzers in the fluctuation group are also in operation, operating in a rated or overloaded state, and the excess power is absorbed by the energy storage system; the output instruction of the mixed integer segmented model is:

8. The wind power hydrogen production system operation strategy according to claim 4, characterized in that: In the fourth mode, only one proton exchange membrane electrolyzer is in operation in the fluctuation group, and the remaining m-1 units are on standby for rotation; in the rated group, x alkaline electrolyzers are working in the rated state, and nx units are in the shutdown state; the output instruction of the mixed integer segmented model is: After the rotation time T is reached, 9. The wind power hydrogen production system operation strategy according to claim 4, characterized in that: In the fifth mode, all alkaline electrolyzers in the rated group stop running; only one proton exchange membrane electrolyzer in the fluctuation group participates in the fluctuation operation, and the remaining m-1 are on standby for rotation; the output instruction of the mixed integer segmentation model is:

10. The wind power hydrogen production system operation strategy according to claim 4, characterized in that: In the sixth mode, at least one proton exchange membrane electrolyzer in the fluctuation group is maintained at the lowest ideal operating state, the others enter the standby state, the alkaline electrolyzer in the rated group stops running, and the output instruction of the mixed integer segmented model is:

Images