Self-adaptive cooperative control method of wind-storage-hydrogen system considering SOC (State of Charge) state

Abstract

The invention discloses a self-adaptive cooperative control method for a wind-storage-hydrogen system considering an SOC (State of Charge) state. The method comprises the following steps: A, sampling the SOC and the hydrogen production power Pel in real time; b, when the SOC is in a normal working area, the SOC works normally; when the SOC is lower than the normal working area, entering the step C; when the SOC is higher than the normal working area, entering the step D; c, judging whether the SOC is in an over-discharge buffer area or not, if so, entering a step G, and otherwise, exiting the hydrogen production unit; d, judging whether the SOC is in an overcharge buffer area or not, if so, entering the step E, and otherwise, exiting the energy storage unit; e, judging whether the SOC is in an overcharge buffer low-level region or not, if so, entering a step G, and otherwise, entering a step F; f, actively reducing MPPT operation of the wind power unit; g, the sampled hydrogen production power Pel is corrected, and a corrected hydrogen production power instruction # imgabs0 # is obtained for a hydrogen production device to operate. According to the method, the hydrogen production power of the hydrogen production device can be dynamically optimized, and the energy storage battery is protected.

Description

Technical Field

[0001] The present invention belongs to the field of wind turbines participating in hydrogen production technology, especially refers to the optimization control technology of energy storage units in isolated wind-storage-hydrogen systems. Specifically, it is an adaptive collaborative control method of wind-storage-hydrogen systems considering the SOC state. Background Art

[0002] In a non-grid-connected DC microgrid architecture, the energy storage system's power regulation capability must be dynamically matched to its real-time SOC to ensure optimal power balance among all units within the system. Energy storage combined with wind power in hydrogen production can improve hydrogen production, but insufficient energy storage power can occur when the SOC approaches upper and lower limits. At this point, it's difficult to balance energy storage SOC protection with hydrogen production effectiveness. Therefore, when hydrogen production and energy storage operate in tandem, it's crucial to study the proper power distribution between the two, as well as the SOC protection of the energy storage device.

[0003] Traditional droop control strategies are widely used for energy storage power distribution and SOC optimization due to their simplicity and reliability. However, in traditional droop control strategies, the droop coefficient is typically fixed, maintaining a constant charge and discharge power of the energy storage battery, making it difficult to achieve reasonable power distribution and optimal SOC control. To address this issue, existing research has focused on improving droop control methods to enhance system flexibility and efficiency.

[0004] Some studies have introduced SOC weighting factors to dynamically adjust the droop coefficient, allowing the energy storage battery to automatically reduce discharge power when the SOC is high. Others have used adaptive control algorithms to optimize droop parameters in real time, such as droop coefficient adjustment based on fuzzy logic or neural networks. Still others have combined model predictive control (MPC) to optimize power allocation across multiple time scales. However, these methods remain insufficient in wind power hydrogen production scenarios, as most studies have not considered the impact of variable power operation of the electrolyzer on the energy storage SOC.

[0005] In summary, relatively little research has been conducted on energy storage SOC protection in wind power-assisted hydrogen production, and further research is needed. Therefore, this paper proposes an adaptive coordinated control of a wind-storage-hydrogen system that considers SOC status, thereby improving the performance of energy storage SOC protection when wind turbines are involved in hydrogen production. Summary of the Invention

[0006] The purpose of the present invention is to address the problems existing in the prior art and provide an adaptive coordinated control method for a wind-storage-hydrogen system taking into account the SOC state.

[0007] The purpose of the present invention is to be solved by the following technical solutions:

[0008] An adaptive coordinated control method for a wind-storage-hydrogen system considering the state of charge (SOC) is provided, wherein the wind-storage-hydrogen system includes a wind turbine unit, a hydrogen production unit, an energy storage unit, a control unit for controlling the above three units, and an energy management unit for managing the control unit. The steps of the adaptive coordinated control method are as follows:

[0009] A. The control unit samples the state of charge (SOC) of the energy storage battery and the hydrogen production power (P) of the hydrogen production device in real time. el ;

[0010] B. When the SOC is in the normal operating range, the wind-storage-hydrogen system operates normally; when the SOC is lower than the normal operating range, the process proceeds to step C; when the SOC is higher than the normal operating range, the process proceeds to step D;

[0011] C. Determine whether the SOC is in the over-discharge buffer zone. If so, proceed to step G; otherwise, control the hydrogen production unit to exit operation;

[0012] D. Determine whether the SOC is in the overcharge buffer zone. If so, proceed to step E. Otherwise, control the energy storage unit to exit operation.

[0013] E. Determine whether the SOC is in the overcharge buffer low range. If yes, proceed to step G; otherwise, proceed to step F.

[0014] F. Wind power units actively reduce MPPT operation;

[0015] G. Based on the data sampled in step A, the hydrogen production power P of the hydrogen production device el Make corrections to obtain the corrected hydrogen production power instruction Go to step H;

[0016] H. The hydrogen production device follows the revised hydrogen production power instruction run.

[0017] The adaptive cooperative control method is based on the state of charge SOC of the energy storage battery and the hydrogen production power P of the hydrogen production device. el As the input quantity, the hydrogen production power P of the hydrogen production device when the state of charge SOC of the energy storage battery is in the over-discharge buffer zone and the over-charge buffer low zone is calculated. el Correction is performed, and the hydrogen production power instruction obtained after correction is As a new reference value for hydrogen production power, it ensures that the state of charge (SOC) of the energy storage battery is in a reasonable range to avoid overcharging and over-discharging.

[0018] The mathematical model used by the wind turbine in the wind turbine unit is:

[0019]

[0020] In formula (1)-formula (2), Pm is the wind energy capture power of the wind turbine; ρ is the air density; R is the rotor radius; v is the wind speed; C p is the wind energy utilization coefficient; β is the pitch angle; λ is the tip speed ratio, which is defined as λ = ωR / v, where ω is the speed of the wind turbine; λ1 is a coefficient obtained from λ; K opt is the optimal wind capture coefficient; λ opt is the optimal tip speed ratio; P max is the maximum wind energy capture power of the wind turbine; is the maximum wind energy utilization coefficient.

[0021] The mathematical model used by the hydrogen production device in the hydrogen production unit is:

[0022]

[0023] In formula (3), U el is the output voltage of a single alkaline electrolyzer; U rev is the reversible voltage of a single alkaline electrolytic cell; r1, r2 are the ohmic resistance parameters of the alkaline electrolytic cell; T el is the operating temperature of the alkaline electrolyzer; is the empirical parameter of overvoltage of alkaline electrolyzer; S el is the electrode surface area of ​​the alkaline electrolytic cell; I el is the working current of the hydrogen production device; U r0 is the reversible voltage of the alkaline electrolytic cell under standard conditions; K rev is the temperature empirical coefficient of the reversible voltage; U elc is the total output voltage when multiple alkaline electrolyzers are connected in series, i.e. the operating voltage of the hydrogen production device; n c is the number of alkaline electrolytic cells connected in series; P el is the hydrogen production power of the hydrogen production device.

[0024] The energy storage batteries in the energy storage unit are divided into five working intervals according to the state of charge (SOC) and seven critical values ​​are defined. The working intervals include:

[0025] Overcharge area, its SOC range is [SOC max ,SOC full ], that is, [90%, 100%];

[0026] Overcharge buffer, its SOC range is (SOC high ,SOC max ), i.e. (70%, 90%);

[0027] The normal operating area, its SOC range is [SOC low ,SOC high ], i.e. [30%, 70%];

[0028] Over discharge buffer, its SOC range is (SOC min ,SOC low ), i.e. (10%, 30%);

[0029] Over discharge area, its SOC range is [SOC empty ,SOC min ], i.e. [0,10%];

[0030] The SOC range of the overcharge buffer is further divided into the overcharge buffer low area and the overcharge buffer high area. The SOC range of the overcharge buffer low area is (SOC high ,SOC op ), that is (70%, 80%), the SOC range of the overcharge buffer high area is [SOC op ,SOC max ), i.e. [80%, 90%);

[0031] The 7 SOC critical values ​​are: SOC full =100%, SOC max =90%, SOC op =80%, SOC high =70%, SOC low =30%, SOC min =10%, SOC empty =0.

[0032] The wind-storage-hydrogen system provided by the present invention includes a wind turbine unit, a hydrogen production unit, and an energy storage unit. When the energy storage is overcharged, the hydrogen production unit can be adjusted to allow the hydrogen production device to absorb more power, or the wind turbine unit can be adjusted to reduce the power output of the wind turbine. Both of these can alleviate the problem of energy storage overcharge, so the overcharge buffer zone is divided into two sub-intervals. When the energy storage is over-discharged, because the wind turbine is already operating at maximum power and cannot generate more power, the hydrogen production unit can only be adjusted to allow the hydrogen production device to absorb less power, so the over-discharge buffer zone is not divided into sub-intervals.

[0033] The wind-storage-hydrogen system is divided into six operating modes based on the state of charge (SOC) of the energy storage battery in the energy storage unit:

[0034] Working mode 1: When the state of charge SOC of the energy storage battery is in the range [SOC low ,SOC high ], the energy storage battery is in the normal working area, the wind-storage-hydrogen system is working normally, and there is no need to consider the problem of overcharging or over-discharging;

[0035] Working mode 2: When the state of charge (SOC) of the energy storage battery is in the range (SOC high ,SOC op), the energy storage battery is in the overcharge buffer zone and there is an overcharge problem. It is necessary to calculate the state of charge SOC of the energy storage battery sampled by the control unit and the hydrogen production power P of the hydrogen production device. el The hydrogen production power P of the hydrogen production device el Make corrections and set the corrected hydrogen production power instruction Feedback to the hydrogen production device for execution;

[0036] Working mode 3: When the state of charge SOC of the energy storage battery is in the range [SOC op ,SOC max ), the energy storage battery is in the overcharge buffer zone and there is an overcharge problem. At this time, the hydrogen production power P of the hydrogen production device el The rated power of the hydrogen production device has been reached. If the energy storage battery is still charging, the speed of the wind turbine is adjusted to enable the wind turbine to actively reduce the MPPT operation;

[0037] Working mode 4: When the state of charge SOC of the energy storage battery is in the range (SOC min ,SOC low ), the energy storage battery is in the over-discharge buffer zone and there is an over-discharge problem. It is necessary to calculate the state of charge SOC of the energy storage battery sampled by the control unit and the hydrogen production power P of the hydrogen production device. el The hydrogen production power P of the hydrogen production device el Make corrections and set the corrected hydrogen production power instruction Feedback to the hydrogen production device for execution;

[0038] Working mode 5: When the state of charge SOC of the energy storage battery is in the range [SOC max ,SOC full ], the energy storage battery is in the overcharge area and the energy storage unit exits operation;

[0039] Working mode 6: When the state of charge SOC of the energy storage battery is in the range [SOC empty ,SOC min ], the energy storage battery is in the over-discharge area and the hydrogen production unit exits operation.

[0040] The specific steps of the wind power unit actively reducing MPPT operation in step F are:

[0041] F1. Calculate the change in the state of charge (SOC) of the energy storage battery using formula (4):

[0042]

[0043] In formula (4), ΔSOC is the change in the state of charge (SOC) of the energy storage battery obtained from two consecutive samplings; Q m is the maximum capacity of the energy storage battery; i batis the current of the energy storage battery; τ is the time constant;

[0044] F2. Let γ = 1 + c·ΔSOC / Δt, where γ is the adjustment coefficient; c is a non-negative constant, ΔSOC / Δt is the gradient of the change in the state of charge (SOC) over time, and c·ΔSOC / Δt is the step size. If the gradient is large, indicating that the SOC is increasing rapidly at that time point, a larger step size is added to increase γ more; if the gradient is small, indicating that the SOC is increasing slowly at that time point, a smaller step size is added to increase γ less.

[0045] F3, adjust the wind turbine speed ω in the fan unit so that the wind turbine speed no longer tracks the optimal speed ω opt , but track the speed of the MPPT when running ω*, ω opt The relationship between and ω* is shown in formula (5):

[0046] ω*=γ·ω opt (5)

[0047] In formula (5), ω opt It corresponds to the optimal speed of the wind turbine when operating in MPPT mode; ω* corresponds to the speed of the wind turbine when operating in MPPT mode; γ is the adjustment coefficient, and γ>1.

[0048] When the wind power unit actively reduces the MPPT operation in step F, the state of charge (SOC) of the energy storage battery is [80%, 90%).

[0049] The corrected hydrogen production power instruction in step G The calculation formula is:

[0050]

[0051] In formula (6)-formula (7), α is the power correction factor; P el The hydrogen production power of the hydrogen production device obtained by sampling; is the corrected hydrogen production power instruction of the hydrogen production device; SOC0 is the initial state of charge of the energy storage battery; SOC is the state of charge of the energy storage battery; P elmax is the rated power of the hydrogen production device; P elmin It is the insulation power of the hydrogen production device.

[0052] When the state of charge SOC of the energy storage battery is in the range (70%, 80%), the energy storage battery is in the overcharge buffer low area, and there is an overcharge problem. It is necessary to adjust the hydrogen production power P of the hydrogen production device. el Make corrections and set the corrected hydrogen production power instruction Feedback to the hydrogen production device for execution, the corrected hydrogen production power instruction The calculation formula is:

[0053]

[0054] In formula (8)-(9), α1 is the power correction factor when the state of charge SOC is in the overcharge buffer low range; P el The hydrogen production power of the hydrogen production device obtained by sampling; is the corrected hydrogen production power instruction of the hydrogen production device; SOC0 is the initial state of charge of the energy storage battery; SOC is the state of charge of the energy storage battery; SOC op P is the upper limit critical value corresponding to the state of charge of the energy storage battery when it is in the overcharge buffer low area; elmax is the rated power of the hydrogen production device.

[0055] When the state of charge SOC of the energy storage battery is in the range (10%, 30%), the energy storage battery is in the over-discharge buffer zone and there is an over-discharge problem. It is necessary to adjust the hydrogen production power P of the hydrogen production device. el Make corrections and set the corrected hydrogen production power instruction Feedback to the hydrogen production device for execution, the corrected hydrogen production power instruction The calculation formula is:

[0056]

[0057] In formula (10) and formula (11), α2 is the power correction factor when the state of charge SOC is in the over-discharge buffer zone; P el The hydrogen production power of the hydrogen production device obtained by sampling; is the corrected hydrogen production power instruction of the hydrogen production device; SOC0 is the initial state of charge of the energy storage battery; SOC is the state of charge of the energy storage battery; SOC min P is the lower critical value corresponding to the state of charge of the energy storage battery in the over-discharge buffer zone; elmin It is the insulation power of the hydrogen production device.

[0058] Compared with the prior art, the present invention has the following advantages:

[0059] The adaptive cooperative control method of the present invention divides the working state of the energy storage battery into multiple working intervals, and samples the state of charge SOC of the energy storage battery and the hydrogen production power P of the hydrogen production device in real time. el , dynamically identify the working range of the state of charge (SOC) and determine the corrected hydrogen production power instruction of the hydrogen production device accordingly The combination of MPPT reduction operation and hydrogen production power correction is used to improve the SOC protection performance of the energy storage battery when the state of charge SOC is close to the upper and lower limits, and the hydrogen production power of the hydrogen production device is dynamically optimized, which has good effectiveness and superiority in energy storage SOC protection. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] Attachment Figure 1 A topological structure diagram of a wind-storage-hydrogen system adopted by an adaptive coordinated control method of a wind-storage-hydrogen system considering SOC state provided by the present invention;

[0061] Attachment Figure 2 The SOC interval division diagram of the energy storage battery provided by the present invention;

[0062] Attachment Figure 3 A schematic diagram of hydrogen production power correction principle of the hydrogen production device provided by the present invention;

[0063] Attachment Figure 4 The relationship curve between the output power and the rotation speed of the wind turbine provided by the present invention;

[0064] Attachment Figure 5 This is a flow chart of a wind-storage-hydrogen system adaptive collaborative control method considering SOC state in the coordinated operation of a wind-storage-hydrogen DC microgrid according to the present invention;

[0065] Attachment Figure 6 A comparison chart of wind turbine power under the overcharge buffer zone between the strategy of the present invention and the strategy in the literature provided in the embodiment;

[0066] Attachment Figure 7 A comparison chart of hydrogen production power between the strategy of the present invention and the strategy in the literature under the overcharge buffer zone provided in the embodiment;

[0067] Attachment Figure 8 A comparison chart of energy storage power between the strategy of the present invention and the strategy in the literature under the overcharge buffer zone provided in the embodiment;

[0068] Attachment Figure 9 A comparison chart of energy storage SOC between the strategy of the present invention and the strategy in the literature under the overcharge buffer zone provided in the embodiment;

[0069] Attachment Figure 10 The wind speed used in the over-discharge buffer zone for the strategies of the present invention and the literature provided in the embodiments;

[0070] Attachment Figure 11 A comparison chart of hydrogen production power between the strategy of the present invention and the strategy in the literature under the over-discharge buffer zone provided in the embodiment;

[0071] Attachment Figure 12 A comparison chart of the energy storage SOC in the over-discharge buffer zone between the strategy of the present invention and the strategy in the literature provided in the embodiment. DETAILED DESCRIPTION

[0072] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be embodied in many forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete and will fully convey the concepts of the example embodiments to those skilled in the art. Like reference numerals in the figures represent like or similar structures, and thus their detailed description will be omitted.

[0073] The terms "a", "an", "the", and "said" are used to indicate the presence of one or more elements / components / etc.; the terms "including" and "having" are used to express an open-ended inclusive meaning and mean that additional elements / components / etc. may be present in addition to the listed elements / components / etc.

[0074] based on Figures 1 to 5 The control block diagram, principle diagram and working flow diagram of the system shown in the figure, the present invention provides an adaptive collaborative control method for a wind-storage-hydrogen system considering the SOC state. The collaborative control method divides the working state of the energy storage system into multiple working intervals, and samples the state of charge SOC of the energy storage battery and the hydrogen production power P of the hydrogen production device in real time. el , dynamically identify the working range of the state of charge (SOC) of the energy storage battery, and modify the hydrogen production power of the hydrogen production device accordingly. At the same time, the adaptive collaborative control method is further optimized in conjunction with the MPPT reduction operation method to improve the SOC protection performance of the energy storage device when the SOC is close to the upper and lower limits.

[0075] The mathematical model of the wind turbine generator system used in the adaptive coordinated control method of the wind-storage-hydrogen system considering the SOC state provided by the present invention is:

[0076]

[0077] In formula (1)-formula (2), P m is the wind energy capture power of the wind turbine; ρ is the air density; R is the rotor radius; v is the wind speed; C p is the wind energy utilization coefficient; β is the pitch angle; λ is the tip speed ratio, which is defined as λ = ωR / v, where ω is the speed of the wind turbine; λ1 is a coefficient obtained from λ; K opt is the optimal wind capture coefficient; λ opt is the optimal tip speed ratio; P max is the maximum wind energy capture power of the wind turbine; is the maximum wind energy utilization coefficient.

[0078] The mathematical model of the hydrogen production device used in the adaptive coordinated control method of the wind-storage-hydrogen system considering the SOC state provided by the present invention is:

[0079]

[0080] In formula (3), U el is the output voltage of a single alkaline electrolyzer; U rev is the reversible voltage of a single alkaline electrolytic cell; r1, r2 are the ohmic resistance parameters of the alkaline electrolytic cell; T el is the operating temperature of the alkaline electrolyzer; is the empirical parameter of overvoltage of alkaline electrolyzer; S el is the electrode surface area of ​​the alkaline electrolytic cell; I el is the working current of the hydrogen production device; U r0 is the reversible voltage of the alkaline electrolytic cell under standard conditions; K rev is the temperature empirical coefficient of the reversible voltage; U elc is the total output voltage when multiple alkaline electrolyzers are connected in series, i.e. the operating voltage of the hydrogen production device; n c is the number of alkaline electrolytic cells connected in series; P el is the hydrogen production power of the hydrogen production device.

[0081] The present invention provides an adaptive coordinated control method for a wind-storage-hydrogen system considering the state of charge (SOC). The energy storage batteries in the energy storage unit are divided into five working intervals according to the state of charge (SOC) and seven critical values ​​are defined. The working intervals include:

[0082] Overcharge area, its SOC range is [SOC max ,SOC full ], that is, [90%, 100%];

[0083] Overcharge buffer, its SOC range is (SOC high ,SOC max ), i.e. (70%, 90%);

[0084] The normal operating area, its SOC range is [SOC low ,SOC high ], i.e. [30%, 70%];

[0085] Over discharge buffer, its SOC range is (SOC min ,SOC low ), i.e. (10%, 30%);

[0086] Over discharge area, its SOC range is [SOC empty ,SOC min ], i.e. [0,10%];

[0087] The SOC range of the overcharge buffer is further divided into the overcharge buffer low area and the overcharge buffer high area. The SOC range of the overcharge buffer low area is (SOC high ,SOCop ), that is (70%, 80%), the SOC range of the overcharge buffer high area is [SOC op ,SOC max ), i.e. [80%, 90%);

[0088] The 7 SOC critical values ​​are: SOC full =100%, SOC max =90%, SOC op =80%, SOC high =70%, SOC low =30%, SOC min =10%, SOC empty =0;

[0089] The wind-storage-hydrogen system adopts adaptive coordinated control for the energy storage units and hydrogen production units in the overcharge buffer low zone and the over-discharge buffer zone.

[0090] Based on the state of charge (SOC) of the energy storage battery, the operating modes of the wind-storage-hydrogen system are divided into six operating modes:

[0091] Working mode 1: When the state of charge SOC of the energy storage battery is in the range [SOC low ,SOC high ], the energy storage battery is in the normal working area and the wind-storage-hydrogen system is working normally;

[0092] Working mode 2: When the state of charge (SOC) of the energy storage battery is in the range (SOC high ,SOC op ), the energy storage battery is in the overcharge buffer zone and there is an overcharge problem. It is necessary to calculate the state of charge SOC of the energy storage battery sampled by the control unit and the hydrogen production power P of the hydrogen production device. el The hydrogen production power P of the hydrogen production device el Make corrections and set the corrected hydrogen production power instruction Feedback to the hydrogen production device for execution;

[0093] Working mode 3: When the state of charge SOC of the energy storage battery is in the range [SOC op ,SOC max ), the energy storage battery is in the overcharge buffer zone and there is an overcharge problem. At this time, the hydrogen production power P of the hydrogen production device el The rated power of the hydrogen production device has been reached. If the energy storage battery is still charging, the speed of the wind turbine is adjusted to enable the wind turbine to actively reduce the MPPT operation;

[0094] Working mode 4: When the state of charge SOC of the energy storage battery is in the range (SOC min ,SOC low), the energy storage battery is in the over-discharge buffer zone and there is an over-discharge problem. It is necessary to calculate the state of charge SOC of the energy storage battery sampled by the control unit and the hydrogen production power P of the hydrogen production device. el The hydrogen production power P of the hydrogen production device el Make corrections and set the corrected hydrogen production power instruction Feedback to the hydrogen production device for execution;

[0095] Working mode 5: When the state of charge SOC of the energy storage battery is in the range [SOC max ,SOC full ], the energy storage battery is in the overcharge area and the energy storage unit exits operation;

[0096] Working mode 6: When the state of charge SOC of the energy storage battery is in the range [SOC empty ,SOC min ], the energy storage battery is in the over-discharge area and the hydrogen production unit exits operation.

[0097] Based on the above settings, the specific steps of the adaptive coordinated control method of the wind-storage-hydrogen system considering the SOC state provided by the present invention are as follows:

[0098] A. The control unit samples the state of charge (SOC) of the energy storage battery and the hydrogen production power (P) of the hydrogen production device in real time. el ;

[0099] B. When the SOC is in the normal operating range, the wind-storage-hydrogen system operates normally; when the SOC is lower than the normal operating range, the process proceeds to step C; when the SOC is higher than the normal operating range, the process proceeds to step D;

[0100] C. Determine whether the SOC is in the over-discharge buffer zone. If so, proceed to step G; otherwise, control the hydrogen production unit to exit operation;

[0101] D. Determine whether the SOC is in the overcharge buffer zone. If so, proceed to step E. Otherwise, control the energy storage unit to exit operation.

[0102] E. Determine whether the SOC is in the overcharge buffer low range. If yes, proceed to step G; otherwise, proceed to step F.

[0103] F. Wind power units actively reduce MPPT operation;

[0104] G. Based on the data sampled in step A, the hydrogen production power P of the hydrogen production device el Make corrections to obtain the corrected hydrogen production power instruction Go to step H;

[0105] H. The hydrogen production device follows the revised hydrogen production power instruction run.

[0106] In the above step F, when the wind power unit actively reduces the MPPT operation, the state of charge (SOC) of the energy storage battery is [80%, 90%). The specific steps for the wind power unit to actively reduce the MPPT operation are as follows:

[0107] F1. Calculate the change in the state of charge (SOC) of the energy storage battery using formula (4):

[0108]

[0109] In formula (4), ΔSOC is the change in the state of charge (SOC) of the energy storage battery obtained from two consecutive samplings; Q m is the maximum capacity of the energy storage battery; i bat is the current of the energy storage battery; τ is the time constant;

[0110] F2. Let γ = 1 + c·ΔSOC / Δt, where γ is the adjustment coefficient; c is a non-negative constant, ΔSOC / Δt is the gradient of the change in the state of charge (SOC) with respect to time, and c·ΔSOC / Δt is the step size. If the gradient is large, indicating that the SOC is increasing rapidly at that point in time, a larger step size is added to increase γ more. If the gradient is small, indicating that the SOC is increasing slowly at that point in time, a smaller step size is added to increase γ less.

[0111] F3, adjust the wind turbine speed ω in the fan unit so that the wind turbine speed no longer tracks the optimal speed ω opt , but track the speed of the MPPT when running ω*, ω opt The relationship between and ω* is shown in formula (7):

[0112] ω*=γ·ω opt (5)

[0113] In formula (5), ω opt It corresponds to the optimal speed of the wind turbine when operating in MPPT mode; ω* corresponds to the speed of the wind turbine when operating in MPPT mode; γ is the adjustment coefficient, and γ>1.

[0114] Figure 4 That is the relationship curve between the output power and speed of the wind turbine. Figure 4 It can be seen that Corresponding to the optimal speed of the wind turbine when MPPT is running, The calculation formula for the speed of the wind turbine when it is running at reduced MPPT is shown in formula (5). If the speed of the wind turbine is adjusted to increase, the tip speed ratio λ of the wind turbine will no longer be maintained at the optimal value λ. opt Thus, the MPPT operation can be achieved.

[0115] In the above step G, the corrected hydrogen production power instruction The calculation formula is:

[0116]

[0117] In formula (6)-formula (7), α is the power correction factor; P el The hydrogen production power of the hydrogen production device obtained by sampling; is the corrected hydrogen production power instruction of the hydrogen production device; SOC0 is the initial state of charge of the energy storage battery; SOC is the state of charge of the energy storage battery; P elmax is the rated power of the hydrogen production device; P elmin It is the insulation power of the hydrogen production device.

[0118] Based on the state of charge (SOC) of the energy storage battery, the wind-storage-hydrogen system adopts adaptive collaborative control for the energy storage unit and hydrogen production unit in the overcharge buffer low zone, and adopts adaptive collaborative control for the energy storage unit and hydrogen production unit in the over-discharge buffer zone.

[0119] When the state of charge (SOC) of the energy storage battery is in the range (70%, 80%), the energy storage battery is in the overcharge buffer low area, and there is an overcharge problem. It is necessary to adjust the hydrogen production power P of the hydrogen production device. el Make corrections and set the corrected hydrogen production power instruction Feedback to the hydrogen production device for execution, the corrected hydrogen production power instruction The calculation formula is:

[0120]

[0121] In equations (8) and (9), α1 is the power correction factor when the state of charge (SOC) is in the low overcharge buffer region.

[0122] When the state of charge (SOC) of the energy storage battery is in the range (10%, 30%), the energy storage battery is in the over-discharge buffer zone and there is an over-discharge problem. It is necessary to adjust the hydrogen production power P of the hydrogen production device. el Make corrections and set the corrected hydrogen production power instruction Feedback to the hydrogen production device for execution, the corrected hydrogen production power instruction The calculation formula is:

[0123]

[0124] In formula (10) and formula (11), α2 is the power correction factor when the state of charge (SOC) is in the over-discharge buffer zone.

[0125] Example

[0126] A specific embodiment is provided below to further illustrate the control effect of the adaptive coordinated control method of a wind-storage-hydrogen system considering the SOC state provided by the present invention.

[0127] 1. Simulation Analysis

[0128] Based on the different operating ranges of the energy storage battery's state of charge (SOC), the battery's state of charge (SOC) in the overcharge buffer zone and the over-discharge buffer zone was analyzed. Furthermore, to verify the superiority and effectiveness of the adaptive coordinated control method proposed in this invention, a comparative analysis was conducted between an adaptive coordinated control method for a wind-storage-hydrogen system that considers SOC status (hereinafter referred to as the present invention's strategy) and an energy storage adaptive droop control method used in a certain literature (hereinafter referred to as the literature's strategy).

[0129] (I) Simulation parameters are shown in Table 1.

[0130] Table 1 Simulation parameters

[0131]

[0132] (2) Analysis of simulation results

[0133] Figures 6 to 9 The following are comparison diagrams of wind turbine power, hydrogen production power, energy storage power and energy storage SOC of the strategy of the present invention and the strategy in the literature under the overcharge buffer zone; in the simulation, the initial value of the initial state of charge SOC0 of the energy storage battery is set to 79%.

[0134] Depend on Figure 6 It can be seen that between 0 and 35 seconds, the curves of the two strategies are consistent, meaning the wind turbine power is the same, and the energy storage battery's state of charge (SOC) is within [70%, 80%] during this period. When the energy storage battery's SOC reaches 80%, the wind turbine power of the two strategies deviates. Between 35 and 60 seconds, the wind turbine in the strategy of the present invention begins to reduce power, while the wind turbine in the strategy of the reference maintains MPPT operation.

[0135] from Figure 7 It can be seen that during the simulation process of 0 to 60 seconds, the hydrogen production device in the literature strategy maintains constant power operation, while the strategy of the present invention gradually increases the hydrogen production power to the rated power threshold according to the preset slope when the state of charge (SOC) of the energy storage battery is in the range of [70%, 80%]; until the state of charge (SOC) of the energy storage battery increases to 80%, the hydrogen production power increases to the rated power of hydrogen production. When the state of charge (SOC) of the energy storage battery exceeds 80%, the hydrogen production device maintains rated power operation.

[0136] In addition, by Figure 8 and Figure 9It can be seen that the charging power and state of charge (SOC) of the energy storage battery in the strategy of the present invention are both lower than those in the literature, and the difference is small in the first 35 seconds. When the SOC of the energy storage battery is in the range of [80%, 90%], due to the high SOC approaching the upper limit, the charging power and SOC deviation of the two increase with the increase of SOC, as shown in the figure from 35 to 60 seconds. This example verifies the effectiveness of the strategy of the present invention under turbulent wind speeds and when the energy storage battery is in the overcharge buffer condition.

[0137] Figures 10 to 12 The following are comparison diagrams of wind speed, hydrogen production power and state of charge (SOC) of the energy storage battery in the over-discharge buffer zone between the strategy of the present invention and the strategy in the literature; in the simulation, the initial value of the state of charge (SOC) of the energy storage battery is set to 20%.

[0138] from Figure 11 It can be seen that during the simulation process of 0 to 60 seconds, the hydrogen production device in the literature strategy maintains constant power operation, while the strategy of the present invention gradually decays the hydrogen production power to the insulation power threshold according to the preset slope when the state of charge (SOC) of the energy storage battery is in the range of [10%, 30%]. When the state of charge (SOC) of the energy storage battery is less than 10%, the system automatically switches to the insulation power operation mode to ensure the safety of the electrolyzer equipment and maintain the lowest energy consumption.

[0139] Depend on Figure 12 It can be seen that when the energy storage battery's state of charge (SOC) operates in the over-discharge buffer zone, the secondary power distribution can adaptively adjust the hydrogen production power, reducing the battery's energy release. Therefore, the energy storage battery's state of charge (SOC) of the strategy of the present invention is higher than that of the reference strategy. Furthermore, as the energy storage battery's state of charge (SOC) decreases, the deviation between the two increases, meaning that the superiority of the strategy of the present invention becomes more pronounced as the energy storage battery's state of charge (SOC) decreases. This example demonstrates the effectiveness of the strategy of the present invention when the energy storage battery is in the over-discharge buffer zone under turbulent wind speeds.

[0140] From the above analysis, it can be seen that the strategy of the present invention can better dynamically optimize the hydrogen production power and has a better energy storage SOC protection effect. Compared with the strategy in the literature, the strategy proposed in the present invention has more advantages in energy storage SOC protection.

[0141] The adaptive collaborative control method of the present invention proposes a strategy for dynamically optimizing the hydrogen production power of the hydrogen production device based on the state of charge (SOC) of the energy storage battery. This strategy quantifies the mathematical relationship between the state of charge (SOC) of the energy storage battery and the hydrogen production power of the hydrogen production device, and derives a correction value for the hydrogen production power based on this relationship. The proposed strategy has good effectiveness and superiority in protecting the energy storage SOC.

[0142] In the embodiments of the present invention, the term "plurality" refers to two or more, unless otherwise specified. Terms such as "installed," "connected," and "fixed" should be interpreted broadly. For example, "connected" can refer to a fixed connection, a detachable connection, or an integral connection. Those skilled in the art will understand the specific meanings of these terms in the embodiments of the present invention based on specific circumstances.

[0143] In the description of the embodiments of the present invention, it should be understood that the terms "upper" and "lower" and the like indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, rather than indicating or implying that the device or unit referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they cannot be understood as limitations on the embodiments of the present invention.

[0144] Throughout this specification, terms such as "one embodiment" and "a preferred embodiment" mean that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, schematic representations of these terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0145] The above embodiments are only for illustrating the technical ideas of the present invention and cannot be used to limit the scope of protection of the present invention. Any changes made on the basis of the technical solutions in accordance with the technical ideas proposed by the present invention fall within the scope of protection of the present invention; any technologies not involved in the present invention can be implemented by existing technologies.

Claims

1. An adaptive coordinated control method for a wind-storage-hydrogen system considering the SOC state, characterized by: The wind-storage-hydrogen system based on the adaptive collaborative control method includes a wind turbine unit, a hydrogen production unit, an energy storage unit, a control unit for controlling the above three units, and an energy management unit for managing the control unit. The steps of the adaptive collaborative control method are as follows: A. The control unit samples the state of charge (SOC) of the energy storage battery and the hydrogen production power (P) of the hydrogen production device in real time. el ; B. When the SOC is in the normal operating range, the wind-storage-hydrogen system operates normally; when the SOC is lower than the normal operating range, the process proceeds to step C; when the SOC is higher than the normal operating range, the process proceeds to step D; C. Determine whether the SOC is in the over-discharge buffer zone. If so, proceed to step G; otherwise, control the hydrogen production unit to exit operation; D. Determine whether the SOC is in the overcharge buffer zone. If so, proceed to step E. Otherwise, control the energy storage unit to exit operation. E. Determine whether the SOC is in the overcharge buffer low range. If yes, proceed to step G; otherwise, proceed to step F. F. Wind power units actively reduce MPPT operation; G. Based on the data sampled in step A, the hydrogen production power P of the hydrogen production device el Make corrections to obtain the corrected hydrogen production power instruction Go to step H; H. The hydrogen production device follows the revised hydrogen production power instruction run.

2. The adaptive coordinated control method of a wind-storage-hydrogen system considering SOC state according to claim 1 is characterized in that: The mathematical model used by the wind turbine in the wind turbine unit is: In formula (1)-formula (2), P m is the wind energy capture power of the wind turbine; ρ is the air density; R is the rotor radius; v is the wind speed; C p is the wind energy utilization coefficient; β is the pitch angle; λ is the tip speed ratio, which is defined as λ = ωR / v, where ω is the speed of the wind turbine; λ1 is a coefficient obtained from λ; K opt is the optimal wind capture coefficient; λ opt is the optimal tip speed ratio; P max is the maximum wind energy capture power of the wind turbine; is the maximum wind energy utilization coefficient.

3. The adaptive coordinated control method of a wind-storage-hydrogen system considering SOC state according to claim 1 is characterized in that: The mathematical model used by the hydrogen production device in the hydrogen production unit is: In formula (3), U el is the output voltage of a single alkaline electrolyzer; U rev is the reversible voltage of a single alkaline electrolytic cell; r1, r2 are the ohmic resistance parameters of the alkaline electrolytic cell; T el is the operating temperature of the alkaline electrolytic cell; k el , is the empirical parameter of overvoltage of alkaline electrolyzer; S el is the electrode surface area of ​​the alkaline electrolytic cell; I el is the working current of the hydrogen production device; U r0 is the reversible voltage of the alkaline electrolytic cell under standard conditions; K rev is the temperature empirical coefficient of the reversible voltage; U elc is the total output voltage when multiple alkaline electrolyzers are connected in series, i.e. the operating voltage of the hydrogen production device; n c is the number of alkaline electrolytic cells connected in series; P el is the hydrogen production power of the hydrogen production device.

4. The adaptive coordinated control method of a wind-storage-hydrogen system considering SOC state according to claim 1 is characterized in that: The energy storage batteries in the energy storage unit are divided into five working intervals according to the state of charge (SOC) and seven critical values ​​are defined. The working intervals include: Overcharge area, its SOC range is [SOC max ,SOC full ], that is, [90%, 100%]; Overcharge buffer, its SOC range is (SOC high ,SOC max ), i.e. (70%, 90%); The normal operating area, its SOC range is [SOC low ,SOC high ], i.e. [30%, 70%]; Over discharge buffer, its SOC range is (SOC min ,SOC low ), i.e. (10%, 30%); Over discharge area, its SOC range is [SOC empty ,SOC min ], i.e. [0,10%]; The SOC range of the overcharge buffer is further divided into the overcharge buffer low area and the overcharge buffer high area. The SOC range of the overcharge buffer low area is (SOC high ,SOC op ), that is (70%, 80%), the SOC range of the overcharge buffer high area is [SOC op ,SOC max ), i.e. [80%, 90%); The 7 SOC critical values ​​are: SOC full =100%, SOC max =90%, SOC op =80%, SOC high =70%, SOC low =30%, SOC min =10%, SOC empty =0.

5. The adaptive coordinated control method of the wind-storage-hydrogen system considering the SOC state according to claim 4 is characterized in that: The wind-storage-hydrogen system is divided into six operating modes based on the state of charge (SOC) of the energy storage battery in the energy storage unit: Working mode 1: When the state of charge SOC of the energy storage battery is in the range [SOC low ,SOC high ], the energy storage battery is in the normal working area and the wind-storage-hydrogen system is working normally; Working mode 2: When the state of charge (SOC) of the energy storage battery is in the range (SOC high ,SOC op ), the energy storage battery is in the overcharge buffer zone and there is an overcharge problem. It is necessary to calculate the state of charge SOC of the energy storage battery sampled by the control unit and the hydrogen production power P of the hydrogen production device. el The hydrogen production power P of the hydrogen production device el Make corrections and set the corrected hydrogen production power instruction Feedback to the hydrogen production device for execution; Working mode 3: When the state of charge SOC of the energy storage battery is in the range [SOC op ,SOC max ), the energy storage battery is in the overcharge buffer zone and there is an overcharge problem. At this time, the hydrogen production power P of the hydrogen production device el The rated power of the hydrogen production device has been reached. If the energy storage battery is still charging, the speed of the wind turbine is adjusted to enable the wind turbine to actively reduce the MPPT operation; Working mode 4: When the state of charge SOC of the energy storage battery is in the range (SOC min ,SOC low ), the energy storage battery is in the over-discharge buffer zone and there is an over-discharge problem. It is necessary to calculate the state of charge SOC of the energy storage battery sampled by the control unit and the hydrogen production power P of the hydrogen production device. el The hydrogen production power P of the hydrogen production device el Make corrections and set the corrected hydrogen production power instruction Feedback to the hydrogen production device for execution; Working mode 5: When the state of charge SOC of the energy storage battery is in the range [SOC max ,SOC full ], the energy storage battery is in the overcharge area and the energy storage unit exits operation; Working mode 6: When the state of charge SOC of the energy storage battery is in the range [SOC empty ,SOC min ], the energy storage battery is in the over-discharge area and the hydrogen production unit exits operation.

6. The method for adaptive coordinated control of a wind-storage-hydrogen system considering SOC state according to any one of claims 1 to 5, characterized in that: The specific steps of the wind power unit actively reducing MPPT operation in step F are: F1. Calculate the change in the state of charge (SOC) of the energy storage battery using formula (4): In formula (4), ΔSOC is the change in the state of charge (SOC) of the energy storage battery obtained from two consecutive samplings; Q m is the maximum capacity of the energy storage battery; i bat is the current of the energy storage battery; τ is the time constant; F2. Let γ = 1 + c·ΔSOC / Δt, where γ is the adjustment coefficient; c is a non-negative constant, ΔSOC / Δt is the gradient of the change in state of charge (SOC) with respect to time, and c·ΔSOC / Δt is the step size; F3, adjust the wind turbine speed ω in the fan unit so that the wind turbine speed no longer tracks the optimal speed ω opt , but track the speed of the MPPT when running ω*, ω opt The relationship between and ω* is shown in formula (5): ω*=γ·ω opt (5) In formula (5), ω opt It corresponds to the optimal speed of the wind turbine when operating in MPPT mode; ω* corresponds to the speed of the wind turbine when operating in MPPT mode; γ is the adjustment coefficient, and γ>1.

7. The adaptive coordinated control method of a wind-storage-hydrogen system considering SOC state according to claim 6 is characterized in that: When the wind power unit actively reduces the MPPT operation in step F, the state of charge (SOC) of the energy storage battery is [80%, 90%).

8. The method for adaptive coordinated control of a wind-storage-hydrogen system considering SOC state according to any one of claims 1 to 5, characterized in that: The corrected hydrogen production power instruction in step G The calculation formula is: In formula (6)-formula (7), α is the power correction factor; P el The hydrogen production power of the hydrogen production device obtained by sampling; is the corrected hydrogen production power instruction of the hydrogen production device; SOC0 is the initial state of charge of the energy storage battery; SOC is the state of charge of the energy storage battery; P elmax is the rated power of the hydrogen production device; P elmin It is the insulation power of the hydrogen production device.

9. The method for adaptive coordinated control of a wind-storage-hydrogen system considering SOC state according to any one of claims 1 to 5, characterized in that: When the state of charge SOC of the energy storage battery is in the range (70%, 80%), the energy storage battery is in the overcharge buffer low area, and there is an overcharge problem. It is necessary to adjust the hydrogen production power P of the hydrogen production device. el Make corrections and set the corrected hydrogen production power instruction Feedback to the hydrogen production device for execution, the corrected hydrogen production power instruction The calculation formula is: In formula (8)-(9), α1 is the power correction factor when the state of charge SOC is in the overcharge buffer low range; P el The hydrogen production power of the hydrogen production device obtained by sampling; is the corrected hydrogen production power instruction of the hydrogen production device; SOC0 is the initial state of charge of the energy storage battery; SOC is the state of charge of the energy storage battery; SOC op P is the upper limit critical value corresponding to the state of charge of the energy storage battery when it is in the overcharge buffer low area; elmax is the rated power of the hydrogen production device.

10. The method for adaptive coordinated control of a wind-storage-hydrogen system considering SOC state according to any one of claims 1 to 5, characterized in that: When the state of charge SOC of the energy storage battery is in the range (10%, 30%), the energy storage battery is in the over-discharge buffer zone and there is an over-discharge problem. It is necessary to adjust the hydrogen production power P of the hydrogen production device. el Make corrections and set the corrected hydrogen production power instruction Feedback to the hydrogen production device for execution, the corrected hydrogen production power instruction The calculation formula is: In formula (10) and formula (11), α2 is the power correction factor when the state of charge SOC is in the over-discharge buffer zone; P el The hydrogen production power of the hydrogen production device obtained by sampling; is the corrected hydrogen production power instruction of the hydrogen production device; SOC0 is the initial state of charge of the energy storage battery; SOC is the state of charge of the energy storage battery; SOC min P is the lower critical value corresponding to the state of charge of the energy storage battery in the over-discharge buffer zone; elmin It is the insulation power of the hydrogen production device.

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