A method for multi-tank electrolysis cluster participating in grid frequency response interaction

Abstract

The application discloses a kind of multi-tank electrolysis cluster participation grid frequency response interaction method, belong to power system operation control field;After receiving frequency response control instruction, first according to maximum power reserve and maximum system maximum frequency deviation total droop coefficient D and total inertia coefficient H are generated;Second, according to the droop coefficient of different electrolytic tank according to operating power, power limit and electrolytic cluster total droop coefficient, the droop coefficient of different electrolytic tank is generated;Finally, according to the droop coefficient of electrolytic tank and the total inertia coefficient of electrolytic cluster, the inertia coefficient of different electrolytic tank is generated respectively;Compared with the traditional frequency response method, the frequency response method considers the difference of different electrolytic tank operating condition when distributing frequency response coefficient, and maximizes the power reserve of electrolytic cluster in frequency response by optimal allocation of frequency response coefficient, so as to reduce the frequency fluctuation of power system after power imbalance, improve the safety, reliability and stability of system.

Description

Technical Field

[0001] This invention belongs to the field of power system operation and control, and specifically relates to a method for multi-cell electrolytic clusters to participate in grid frequency response interaction. Background Technology

[0002] Climate change is driving the decarbonization of the energy sector, and the concept of integrating renewable energy into the power system and converting excess energy into hydrogen through water electrolyzers is gaining attention due to its environmental and economic benefits. Currently, there are three main types of electrolyzers: alkaline electrolyzers, proton exchange membrane electrolyzers, and solid oxide electrolyzers, with alkaline electrolyzers being the most widely used in industry.

[0003] With the increasing proportion of renewable energy, a key challenge facing power systems is the reduction in system inertia and primary frequency response reserves due to the transition from synchronous machines to inverter-based renewable energy, which threatens system frequency stability. To address this issue, researchers have proposed integrating alkaline electrolyzers into the frequency response of power systems, as they can rapidly adjust operating power. However, an alkaline water electrolysis cluster (AWEP) typically consists of multiple electrolyzer stacks, each operating at different power levels. How to fully utilize the power reserve capacity of the electrolysis cluster and effectively distribute damping and inertia coefficients among these stacks becomes a significant challenge.

[0004] Therefore, this invention analyzes the operating characteristics of alkaline electrolyzers and proposes a method for allocating the frequency response coefficients of multi-cell electrolyzer clusters suitable for large-scale electrolyzer clusters participating in power system frequency response auxiliary services. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the present invention aims to provide a method for multi-cell electrolysis clusters to participate in grid frequency response interaction, thereby maximizing the power reserve provided by the electrolysis clusters in frequency response, optimizing the frequency response capability of the electrolysis clusters, and improving the stability of the power system.

[0006] The objective of this invention can be achieved through the following technical solution: a method for multi-cell electrolytic cell clusters to participate in grid frequency response interaction, the method comprising the following steps:

[0007] Step 1: When the electrolytic cluster receives the frequency response command, the electrolytic cluster generates the total droop coefficient D and the total inertia coefficient H.

[0008] And assign coefficients to the different electrolytic cells that are currently in operation;

[0009] Step 2: The electrolytic cell generates a sag coefficient when the electrolytic cell power is reduced and a sag system when the power is increased, based on its own power, power limit and total sag coefficient of the electrolytic cluster.

[0010] Step 3: The electrolytic cell obtains the inertia coefficient when the power is increased and the inertia coefficient when the power is decreased based on the sag coefficient and the total inertia coefficient when the power is increased / decreased.

[0011] Step 4: The electrolytic cell performs a frequency response based on the generated sag coefficient and inertia coefficient.

[0012] As an improvement to the present invention, the method for generating the electrolytic cluster droop coefficient in step 1 is as follows:

[0013]

[0014] In the formula, MPR represents the maximum power support that the electrolytic cluster can provide at this time, and Δf max D represents the maximum acceptable frequency fluctuation for the power system. awep The frequency response total droop system representing the electrolytic cluster,

[0015] The calculation method for the maximum power support (MPR) that an electrolytic cluster can provide is as follows:

[0016]

[0017] In the formula, the subscript numbers represent the electrolytic cell number, P max P represents the maximum power of the electrolytic cell. ini This represents the initial power of the electrolytic cell.

[0018] In step 1, when the electrolytic cluster assigns coefficients to different operating electrolytic cells, to ensure the overall characteristics exhibited by the electrolytic cluster in its frequency response, the following should be true:

[0019]

[0020] In the formula, D awep,i With H awep,i These represent the sag coefficient and inertia coefficient of the i-th electrolytic cell, respectively.

[0021] Step 2: When the electrolytic cell generates its own frequency response droop coefficient, in order to ensure that the allocated droop coefficient allows all electrolytic cells to reach their power limit under the same frequency fluctuation, the droop coefficient D of the electrolytic cell increases as the power rises because the deviation between the operating power of the electrolytic cell and the maximum and minimum power limits is not equal. awep,i,up With the droop factor D when power decreases awep,down,i The values ​​are different.

[0022] Step 2: When the electrolytic cell generates its own frequency response droop coefficient, the droop coefficient D of the electrolytic cell during power increase. awep,i,up The calculation method is as follows:

[0023]

[0024] Step 2: When the electrolytic cell generates its own frequency response droop coefficient, the droop coefficient D of the electrolytic cell during power reduction. awep,i,down The calculation method is as follows:

[0025]

[0026] In the formula, the subscript numbers represent the electrolytic cell number, P min This represents the minimum power of the electrolytic cell.

[0027] In step 3, when the electrolytic cell generates its own frequency response inertia coefficient, the inertia coefficient during power increase should be proportional to the droop coefficient during power increase:

[0028]

[0029] In step 3, when the electrolytic cell generates its own frequency response inertia coefficient, the inertia coefficient of the electrolytic cell during power reduction should be proportional to the sag coefficient during power reduction:

[0030]

[0031] In step 4, when adjusting the power of the electrolytic cell during frequency response, the following model should be followed:

[0032]

[0033] In the formula, ΔP represents the power change, Δf is the frequency offset, and ref represents the target value for frequency response adjustment.

[0034] The following model should be followed when reducing power:

[0035]

[0036] The beneficial effects of this invention are:

[0037] The method of this invention fully considers the different operating states (power) of different electrolytic cells when the electrolytic cluster participates in frequency response. Through optimal allocation between cells in the frequency response system, different electrolytic cells reach their operating limit power under the same frequency deviation, maximizing the power reserve that the electrolytic cluster can provide in frequency response, thereby reducing the frequency deviation of the system after a fault. By using this frequency response coefficient allocation method, electrolytic cluster operators can obtain more revenue in the ancillary services market.

[0038] This invention innovatively proposes to consider different droop coefficients and inertia coefficients when adjusting power up and down, thereby maximizing the power reserve provided by the electrolyzer to the power system based on the current operating status of the electrolyzer and improving the frequency response of the power system. Attached Figure Description

[0039] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0040] Figure 1 This is a flowchart of the frequency response coefficient slot allocation method of the present invention.

[0041] Figure 2 This is a qualitative comparison chart of the effects of the strategy proposed in this invention and a general frequency response strategy.

[0042] Figure 3 This is a simulation comparison chart of the effects of the strategy proposed in this invention and a general frequency response strategy. Detailed Implementation

[0043] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0044] Example: This invention relates to a method for multi-cell electrolysis clusters to participate in power grid frequency response interaction. Its core feature is that when the electrolysis cluster receives a frequency response command, it needs to generate a droop coefficient D and allocate the coefficient to different operating electrolysis cells.

[0045] To maximize the power reserve provided by the electrolytic cluster in the frequency response, the allocated droop factor should ensure that all electrolytic cells reach their power limit under the same frequency fluctuation.

[0046] Because it is related to the limit of electrolysis power, the droop coefficients when the power of the same electrolytic cell increases and decreases are not equal and need to be considered separately.

[0047] To ensure power synchronization between different electrolytic cells, the inertia coefficient should be proportional to its sag coefficient.

[0048] This embodiment assumes an electrolysis cluster consisting of two electrolytic cells, with a maximum power of 14.4MW and a minimum power of 2.4MW. The initial operating power of the two electrolytic cells is 12.4MW and 4.4MW, respectively.

[0049] Based on the system parameters, the maximum power support (MPR) that the electrolytic cluster can provide at this time can be obtained as follows:

[0050]

[0051] That is, the maximum power support MPR is 12MW. Assume the maximum frequency deviation Δf max Given a frequency of 0.1 Hz, the sag coefficient D of the electrolytic cluster can be calculated at this frequency.

[0052]

[0053] The frequency response inertia coefficient H of the electrolytic cluster awep Set it to 400.

[0054] Furthermore, the sag coefficient of electrolytic cell 1 when the power is increased can be calculated as follows:

[0055]

[0056] The sag coefficient of electrolytic cell 1 when the power is reduced is:

[0057]

[0058] The sag coefficient of electrolytic cell 2 when the power is increased is:

[0059]

[0060] The sag coefficient of electrolytic cell 2 when the power is reduced is:

[0061]

[0062] Furthermore, the inertia coefficient of electrolytic cell 1 when the power is increased can be calculated as follows:

[0063]

[0064] The inertia coefficient of electrolytic cell 1 when the power is reduced is:

[0065]

[0066] The inertia coefficient of electrolytic cell 2 when the power is increased is:

[0067]

[0068] The inertia coefficient of electrolytic cell 2 when the power is reduced is:

[0069]

[0070] Furthermore, the frequency response model of electrolytic cell 1 when the power is increased can be obtained as follows:

[0071]

[0072] The frequency response model of electrolytic cell 1 when the power is reduced is as follows:

[0073]

[0074] The frequency response model of electrolytic cell 2 when the power is increased is as follows:

[0075]

[0076] The frequency response model of electrolytic cell 2 when the power is reduced is as follows:

[0077]

[0078] To further illustrate the superiority of the proposed method, the effectiveness of the proposed electrolytic cell cluster participation frequency response strategy versus the general strategy was compared after a 100MW power system encountered a 10MW power imbalance. The results are attached. Figure 3 As shown in the figure, after the system power imbalance, the steady-state frequency deviation under the proposed strategy is 0.071Hz, while the steady-state frequency deviation under the general strategy is 0.104Hz. This proves that the proposed strategy can provide more power reserves and reduce frequency deviation.

[0079] Appendix Figure 2 A qualitative comparison was made between the proposed cluster frequency response strategy and the general frequency response strategy. As shown in the figure, under power imbalance, the proposed frequency response strategy can achieve power balance with a smaller frequency change, reducing the system frequency deviation and demonstrating the superiority of the proposed strategy.

[0080] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above 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 one or more embodiments or examples.

[0081] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention.

Claims

1. A method for multi-cell electrolytic cell clusters to participate in grid frequency response interaction, characterized in that, The method includes the following steps: Step 1: When the electrolytic cluster receives the frequency response command, the electrolytic cluster generates the total droop coefficient D. awep With the total inertia coefficient H awep , And assign coefficients to the different electrolytic cells that are currently in operation; Step 2: The electrolytic cell generates a droop coefficient when the power is reduced and a droop coefficient when the power is increased, based on its own power, power limit and the maximum frequency fluctuation acceptable to the power system. Step 3: The electrolytic cell obtains the inertia coefficient when the power is increased and the inertia coefficient when the power is decreased based on the sag coefficient and the total inertia coefficient when the power is increased and decreased. Step 4: The electrolytic cell performs a frequency response based on the generated sag coefficient and inertia coefficient.

2. The method for multi-cell electrolytic cell clusters to participate in grid frequency response interaction according to claim 1, characterized in that: The method for generating the electrolytic cluster droop coefficient in step 1 is as follows: In the formula, MPR represents the maximum power support that the electrolytic cluster can provide at this time, and Δf max D represents the maximum acceptable frequency fluctuation for the power system. awep The total droop coefficient representing the frequency response of the electrolytic cluster. The calculation method for the maximum power support (MPR) that an electrolytic cluster can provide is as follows: In the formula, the subscript numbers represent the electrolytic cell number, P max,i P represents the maximum power of the i-th electrolytic cell. ini,i This represents the initial power of the i-th electrolytic cell.

3. The method for multi-cell electrolytic cell clusters to participate in grid frequency response interaction according to claim 2, characterized in that: In step 1, when the electrolytic cluster assigns coefficients to different operating electrolytic cells, to ensure the overall characteristics exhibited by the electrolytic cluster in its frequency response, the following should be true: In the formula, D awep,i With H awep,i These represent the sag coefficient and inertia coefficient of the i-th electrolytic cell, respectively.

4. The method for multi-cell electrolytic clusters to participate in grid frequency response interaction according to claim 3, characterized in that: Step 2: When the electrolytic cell generates its own frequency response droop coefficient, to ensure that the allocated droop coefficient allows all electrolytic cells to reach their power limit under the same frequency fluctuation, the droop coefficient D of the electrolytic cell is adjusted when the power is increased because the deviation between the operating power of the electrolytic cell and the maximum and minimum power limits is not equal. awep,up,i The droop coefficient D when the power is reduced awep,down,i The values ​​are different.

5. A method for multi-cell electrolytic clusters to participate in grid frequency response interaction according to claim 4, characterized in that: Step 2: When the electrolytic cell generates its own frequency response droop coefficient, the droop coefficient D of the electrolytic cell when the power is increased. awep,up,i The calculation method is as follows:

6. A method for multi-cell electrolytic clusters to participate in grid frequency response interaction according to claim 5, characterized in that: Step 2: When the electrolytic cell generates its own frequency response droop coefficient, the droop coefficient D of the electrolytic cell when the power is reduced. awep,down,i The calculation method is as follows: In the formula, the subscript numbers represent the electrolytic cell number, P min This represents the minimum power of the electrolytic cell.

7. A method for multi-cell electrolytic cell clusters to participate in grid frequency response interaction according to claim 6, characterized in that: In step 3, when the electrolytic cell generates its own frequency response inertia coefficient, the inertia coefficient during power increase should be proportional to the droop coefficient during power increase:

8. A method for multi-cell electrolytic cell clusters to participate in grid frequency response interaction according to claim 7, characterized in that: In step 3, when the electrolytic cell generates its own frequency response inertia coefficient, the inertia coefficient of the electrolytic cell during power reduction should be proportional to the sag coefficient during power reduction:

9. A method for multi-cell electrolytic cell clusters to participate in grid frequency response interaction according to claim 8, characterized in that: In step 4, when adjusting the power of the electrolytic cell during frequency response, the following model should be followed: In the formula, ΔP represents the power change, Δf is the frequency offset, and ref represents the target value for frequency response adjustment. The following model should be followed when reducing power:

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