Electric hydrogen production factory and control unit and control method thereof

Abstract

A control unit (40) for an electrical hydrogen production (PtH) plant (100) is provided. The control unit (40) comprises at least one model (41) and is configured to calculate a maximum efficiency point tracking of the PtH plant (100) by solving an objective function having a predetermined hydrogen production rate of the PtH plant or a predetermined amount of energy input to the PtH plant using the at least one model, the control unit receives, as an input to the at least one model, a measured parameter indicative of a state of a component of the PtH plant; determining one or more setpoints for co-operation of the components of the PtH plant based on a solution obtained by solving the objective function; and providing the one or more setpoints to one or more of the components of the PtH plant to operate the PtH at the maximum efficiency point.

Description

Technical Field

[0001] The present disclosure relates to a maximum efficiency point tracking (MEPT) control for a power-to-hydrogen (PtH) plant. Background Art

[0002] Power-to-hydrogen (PtH) is considered one of the most important technologies in the process of decarbonization and carbon neutrality. In this context, PtH has become increasingly popular due to its high quality energy density and environmentally friendly advantages. However, in the prior art, PtH plants are usually operated under constant parameters, which leads to problems of deviation from the high efficiency point of the PtH plant, especially when the PtH plant adopts renewable energy sources that may vary intermittently. This is particularly problematic for large-scale PtH systems because any deviation from the high efficiency point will result in high power losses. Summary of the invention

[0003] According to an embodiment of the present disclosure, a control unit for a power-to-hydrogen (PtH) plant is provided. The control unit includes at least one model and is configured to: calculate the maximum efficiency point tracking of the PtH plant by solving an objective function with a predetermined hydrogen production rate of the PtH plant or a predetermined amount of energy input to the PtH plant using the at least one model, wherein the control unit receives measured parameters indicating the state of components of the PtH plant as input to the at least one model; determine one or more set points for coordinated operation of the components of the PtH plant based on a solution obtained by solving the objective function; and provide the one or more set points to one or more of the components of the PtH plant to operate the PtH at the maximum efficiency point.

[0004] According to another embodiment of the present disclosure, a PtH plant is provided. The PtH plant includes: an electrolyzer for producing hydrogen; a power supply unit for supplying power to the electrolyzer; auxiliary equipment coupled to the electrolyzer; and a control unit in communication with the electrolyzer, the power supply unit, and the auxiliary equipment. The control unit includes at least one model and is configured to: calculate the maximum efficiency point tracking of the PtH plant by solving an objective function having a predetermined hydrogen production rate of the electrolyzer or a predetermined amount of energy input to the PtH plant using the at least one model, wherein the control unit receives measured parameters indicating the status of components of the PtH plant as inputs to the at least one model; determine one or more set points for coordinated operation of the components of the PtH plant based on a solution obtained by solving the objective function; and provide the one or more set points to one or more of the components of the PtH plant to operate the PtH at the maximum efficiency point.

[0005] According to another embodiment of the present disclosure, a control method for a power-to-hydrogen (PtH) plant is provided. The control method includes: calculating the maximum efficiency point tracking of the PtH plant by solving an objective function with a predetermined hydrogen production rate of the PtH plant or a predetermined amount of energy input to the PtH plant using the at least one model, wherein a control unit receives measured parameters indicating the state of components of the PtH plant as input to the at least one model; determining one or more set points for coordinated operation of the components of the PtH plant based on a solution obtained by solving the objective function; and providing the one or more set points to one or more of the components of the PtH plant to operate the PtH at the maximum efficiency point. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] The disclosed aspects will hereinafter be described in conjunction with the accompanying drawings, which are provided to illustrate rather than limit the scope of the present disclosure.

[0007] Figure 1 The multi-energy interconversion in a PtH plant is shown.

[0008] Figure 2 Shown is the effect of gas bubbles in an electrolyser.

[0009] Figure 3 A PtH plant according to an example of the present disclosure is shown.

[0010] Figure 4 Shows Figure 3 An implementation of a PtH plant is shown.

[0011] Figure 5 An example of a distributed control unit is shown.

[0012] Figure 6 An example of a central control unit is shown.

[0013] Figure 7 is a flow chart of an MEPT control process according to one example of the present disclosure.

[0014] Figure 8 is a flowchart of a MEPT control process according to another example of the present disclosure.

[0015] Fig. 9 Examples of two optimizations of power distribution are shown.

[0016] Fig.10 Shows Figure 4 Implementation of PtH shown.

[0017] Fig.11 Shows Figure 4 Another embodiment of the PtH is shown.

[0018] Fig.12 is a flow chart of a control method of a PtH plant according to an example of the present disclosure.

[0019] Fig.13 is a simulation graph showing the synergy of temperature and speed for maximum PtH efficiency.

[0020] Fig.14 is a simulation diagram showing the maximum efficiency and optimized power of the pump, heater and electrolyzer at different supply currents.

[0021] Fig.15 is the efficiency as the supply current fluctuates ( Fig.15 (a)), temperature( Fig.15 (b)), speed( Fig.15 (c)) and voltage ( Fig.15 (d)) Simulation diagram of the maximum efficiency point. DETAILED DESCRIPTION

[0022] Examples of the present disclosure relate to MEPT control of a PtH plant. A PtH plant includes components such as an electrolyzer, auxiliary equipment coupled to the electrolyzer (such as a pump, a heater, a cooler, and a heat exchanger), and a power supply unit for supplying power to the electrolyzer and the auxiliary equipment. A PtH plant is a multi-energy system in which various types of energy, such as electrical energy, thermal energy, mechanical energy, and chemical energy, interact and convert with each other. Multi-energy conversion in a PtH plant is as follows: Figure 1 As shown. Figure 1As shown, the PtH plant is powered by electricity taken from an energy source, which is distributed and converted into mechanical energy, thermal energy and chemical energy between the electrolyzer and auxiliary equipment such as pumps and thermal conditioning equipment (e.g. heaters, coolers or heat exchangers). Different types of energy are carried to the electrolyzer through the flowing electrolyte and converted into chemical energy stored in hydrogen.

[0023] like Figure 2 As shown, the mechanical energy provided by the pump (e.g. flowing electrolyte) has an important influence on the PtH plant due to the so-called bubble effect. Figure 2 (a)), the adhering bubbles on the catalyst isolate the electrolyte from the catalyst, which means that the covered area on the catalyst is ineffective for the electrolyte (e.g., water electrolysis). Therefore, the bubble effect tends to reduce the effective area for electrochemical reactions on the electrodes of the electrolyzer. For interstitial cells (see Figure 2 (b)), the bubbles will not only reduce the effective area of ​​the electrode, but also reduce the conductivity of the electrolyte. This is because the flow channel is contained in the conductive path. Since the conductivity of the bubbles is much lower than that of the electrolyte, the presence of bubbles has a negative impact on the cell resistance. Therefore, sufficient power should be allocated to the pump to ensure the detachment of the bubbles.

[0024] Thermal energy is also important for high performance of PtH plants. High temperatures have two main benefits for electrolysis (e.g., water electrolysis). From a thermodynamic point of view, the electrical energy required for electrolysis (e.g., water splitting) is reduced because more thermal energy is supplied to the electrolyzer. On the other hand, electrodes are better activated at high temperatures, which indicates an increase in energy conversion efficiency.

[0025] An important improvement of the present disclosure is that it provides coordinated control of the various components of a PtH plant using a model to ensure that the PtH plant can operate at a maximum efficiency point. Examples of the present disclosure are described below.

[0026] The MEPT control according to the example of the present disclosure can be applied to medium-sized PtH plants as well as large-sized PtH plants. For example, the power, current, and voltage of a medium-sized electrolyzer in a PtH plant can be 0.5MW, 1800A, and 250V, respectively. The power, current, and voltage of a large-sized electrolyzer in a PtH plant can be 5MW, 5000A, and 1000V, respectively.

[0027] Figure 3A PtH plant 100 according to one example of the present disclosure is shown. The PtH plant 100 obtains energy from an energy source 200. The energy source 200 may be a renewable energy source such as wind, solar, water, or geothermal. The energy source 200 may also be a grid-connected system or an off-grid system. The energy source 200 may also be a hybrid system of a grid and a battery that may deliver electricity during grid-connected or off-grid conditions.

[0028] According to an example of the present disclosure, the efficiency of the PtH plant 100 is represented by the ratio of hydrogen energy generated by the PtH plant 100 to the energy consumed by the PtH plant 100. Examples of the present disclosure are directed to achieving a maximum efficiency point of the PtH plant. The maximum efficiency point is represented by an objective function that includes a maximum ratio corresponding to the maximum efficiency point of the PtH plant.

[0029] The objective function is written as: maxP_H2 / ΣP_i 1≤i≤n (1) where P_H2 is the power of hydrogen produced by the PtH plant; and ΣP_i is the sum of the power consumed by the components of the PtH plant, and n is the number of components.

[0030] In one example, the energy input to the PtH plant 100 is distributed among pumps, heaters, and electrolyzers, and the objective function is written as: where P_H2 is the power of hydrogen produced by the PtH plant; P 泵 is the power consumed by the pump; P 加热器 is the power consumed by the heater; P 电解器 is the power consumed by the electrolyzer.

[0031] In the case where the output of the PtH plant 100 is predetermined, that is, the hydrogen generation rate of the PtH plant 100 is predetermined, for example, the hydrogen generation rate is preset to a certain level according to user requirements, the maximum ratio is the ratio of the hydrogen energy corresponding to the predetermined hydrogen generation rate to the minimum amount of energy required by the PtH plant 100. That is, in the case where the output energy is preset and the energy required to be input to the PtH plant is minimized, the maximum efficiency point of the PtH plant 100 can be achieved.

[0032] In another case, where the input of the PtH plant 100 is predetermined, that is, the amount of energy input to the PtH plant 100 is predetermined, for example, the amount of input energy is preset to a certain level according to a specific use case, the maximum ratio is the ratio of hydrogen energy generated by the PtH plant 100 to the predetermined amount of energy input to the PtH plant 100. That is, the maximum efficiency point of the PtH plant 100 can be achieved when the input energy is preset and the output energy generated by consuming the preset input energy is maximized.

[0033] refer to Figure 3 , the PtH plant 100 includes an electrolyzer 10 , a power supply unit 20 , auxiliary equipment 30 , and a control unit 40 .

[0034] The electrolyzer 10 is used to electrolyze an electrolyte, such as an alkaline solution or water, to generate hydrogen, and also to generate oxygen. The present disclosure is only related to the production of hydrogen.

[0035] The electrolyzer 10 is a core component of the PtH plant 100. Various types of water electrolyzers can be used, such as alkaline water electrolysis (AE), proton exchange membrane water electrolysis (PEM) and anion exchange membrane water electrolysis (AEM). These electrolyzers have their own characteristics. For example, AE is considered to be the most mature technology with low investment cost and high capacity. Due to the excellent performance of polymer membranes, PEM is characterized by high current density and partial load range. The MEPT control of the present disclosure can be applied to those types of water electrolyzers.

[0036] The power supply unit 20 receives power obtained from the energy source 200 and supplies power to the electrolyzer 10 and the auxiliary equipment 30. The output of the power supply unit 20 is adjustable, for example, by controlling at least one of the output current, output voltage and output power of the power supply unit 20, so the power supplied to each of the electrolyzer 10 and the auxiliary equipment 30 is also adjustable.

[0037] The auxiliary device 30 is coupled to the electrolyzer 10. In one example, the auxiliary device 30 is integrated with the electrolyzer 10 to form a single device. The auxiliary device 30 includes a pump for pumping electrolyte into the electrolyzer 10. The pump has an adjustable pump speed to adjust the flow rate of the electrolyte pumped into the electrolyzer 10. The auxiliary device 30 may also include at least one of a heater, a cooler, and a heat exchanger for adjusting the temperature of the electrolyte.

[0038] The control unit 40 communicates with the electrolyser 10, the power supply unit 20 and the auxiliary equipment 30, respectively. The control unit 40 includes a MEPT control strategy that cooperatively controls the components of the PtH plant so that the PtH plant can operate at a maximum efficiency point.

[0039] Continue to refer Figure 3, the control unit 40 includes at least one model 41. The at least one model can be implemented by various techniques, such as a lookup table, a formula, an equation, an AI-based model, and an NM-based model. In one example, the at least one model includes variables, coefficients, and constants.

[0040] In one example, the control unit 40 receives predetermined information Info_1 (i.e., a predetermined hydrogen production rate or a predetermined energy input to the PtH plant 100) and measurement information Info_2 (i.e., measured parameters indicating the status of components of the PtH plant 100). The measured parameters are input to at least one model 41 as variables of the at least one model 41. Then, the control unit 40 calculates the MEPT of the PtH plant 100 by solving the objective function using the at least one model 41. Then, the control unit 40 determines one or more set points for the coordinated operation of the components of the PtH plant 100 based on the solution obtained by solving the objective function. The obtained solution can be regarded as an optimal solution for achieving the maximum efficiency defined by the objective function. Then, the control unit 40 provides one or more set points to one or more of the components of the PtH plant 100 to operate the PtH 100 at the maximum efficiency point.

[0041] In some cases, there may be a problem of aging of the electrolyzer 10, so that at least one model 41 is no longer suitable for the current situation of the PtH plant 100. In view of this problem, according to an example of the present disclosure, the control unit 40 performs an update of at least one model 41 to solve the problem. The update can be performed online and / or offline. The update can be performed periodically (for example, once a month or once a year) or in response to a trigger signal indicating that the aging of the electrolyzer has reached a certain level.

[0042] In one example, the control unit 40 calculates an update of the at least one model 41 based on the measured parameters. The update of the at least one model 41 comprises an update of coefficients and / or constants of the at least one model 41.

[0043] The coefficients and constants of the at least one model 41 include those parameters related to the electrochemical reactions, two-phase flow, and temperature dependence of the electrolyzer 10. Examples of the coefficients and constants of the at least one model 41 are described in Table 1 below. Table 1

[0044] In one example, the measured parameters include parameters measured at components of the PtH plant 100 and indicative of component status. For example, the measured parameters include: current in the electrolyzer 10 (e.g., current flowing from an anode electrode of the electrolyzer to a cathode electrode of the electrolyzer); voltage across the electrolyzer 10; velocity of electrolyte flowing into the electrolyzer 10; and temperature of the electrolyte in the electrolyzer 10.

[0045] In addition, an aging index indicating the degree of aging of the electrolyzer 10 can be derived from the measured parameters. For example, the aging index is calculated based on the measured electrolyzer voltage and current and the hydrogen production rate. In one example, the control unit 40 calculates the aging index based on the measured parameters. In another example, the aging index is calculated at a computing device associated with the electrolyzer 10, and the control unit 40 receives the aging index from the computing device.

[0046] In one example, the measured parameters include variables related to the electrochemical reaction, two-phase flow, and temperature dependence of the electrolyzer 10. Examples of these variables are described in Table 2 below. Table 2

[0047] In one example, the measured parameters may also include operating parameters of a pump.The measured parameters may also include operating parameters of one or more of a heater, a cooler, and a heat exchanger.

[0048] The set point includes one or more of the following reference values ​​that should work together: a reference current of the power supply unit 20, a reference voltage of the power supply unit 20, a reference power of the power supply unit 20, a reference temperature of at least one of the heater 32, the cooler 33, and the heat exchanger 34, and a reference speed of the pump 31. In one example, the control unit 40 determines one set point including all the determined reference values, for example, the determined set point includes the reference voltage, the reference temperature, and the reference speed. In another example, the control unit 40 determines a group of set points, each of which includes one reference value, for example, the determined group of set points includes a set point for setting a reference voltage, a set point for setting a reference temperature, and a set point for setting a reference speed.

[0049] A set point including a reference value is provided as a command to a corresponding component. Each component may be associated with a controller for receiving and executing commands (e.g., the controller may be considered as a low-level controller / slave controller of the control unit 40). For example, a set point for setting a reference speed is provided to a pump controller associated with a pump, and the pump controller controls the pump so that the pump pumps electrolyte into the electrolyzer 10 at a reference speed. In this way, the components of the PtH plant 100 may be cooperatively controlled based on cooperative work according to the set point command.

[0050] Figure 4 Produced Figure 3 Implementation of the PtH plant 100. Figure 4 As shown, the PtH plant 100 further includes a sensing unit 50. The sensing unit 50 includes one or more sensors for sensing the states of the electrolyzer 10, the power supply unit 20, and the auxiliary equipment 30 and generating the above-mentioned measured parameters (i.e., Info_2). In addition, the PtH plant 100 may further include a communication network 60 (e.g., Figure 5 and 6 Information may be exchanged between the control unit 40 and the electrolyzer 10 , the power supply unit 20 , the auxiliary device 30 , or the sensing unit 50 via the communication network 60 .

[0051] refer to Figure 4 The power supply unit 20 includes a power supply 21, and optionally, includes a converter 22 coupled to the power supply 21. The converter 22 may include a converter such as AC-DC, DC-DC, DC-AC-DC, etc. The power supply 21 may include one or more power supplies. The converter 22 may include one or more converters. The selection of the converter 22 and its arrangement with the power supply 21 may be designed according to a specific application scenario. The auxiliary device 30 includes a pump 31, and optionally, includes at least one of a heater 32, a cooler 33, and a heat exchanger 34.

[0052] Continue to refer Figure 4, at least one model 41 includes an electrolyzer model 411 and a pump model 412. The electrolyzer model 411 is a model of the electrolyzer 10 obtained by modeling the electrolyzer 10. The pump model 412 is a model of the pump obtained by modeling the pump 31. At least one model 41 may also include a heater model 413, a cooler model 414, and a heat exchanger model 415. Similarly, the heater model 413 is a model of the heater 32 obtained by modeling the heater 32. The cooler model 414 is a model of the cooler 33 obtained by modeling the cooler 33. The heat exchanger model 415 is a model of the heat exchanger 34 obtained by modeling the heat exchanger 34. In one example, each of those models 411-415 is implemented as a sub-model of the model 41 and has a data interface for exchanging data with each other. Those models 411-415 perform collaborative processing for determining one or more set points.

[0053] According to an example of the present disclosure, the control unit 40 may be implemented as a distributed control unit or a central control unit.

[0054] Figure 5 An example of a distributed control unit 40 is shown. Figure 5 As shown, the control unit 40 includes a plurality of controllers 40A-40C, each of which can communicate with a communication network 50. At least one model 41 is stored in one of the controllers, for example, the controller 40A.

[0055] Figure 6 An example of a central control unit 40 is shown. Figure 6 As shown, the control unit 40 includes a central controller 40D. At least one model 41 is stored in the central controller 40D.

[0056] Figure 7 is a flow chart of an exemplary MEPT control process 700 according to the present disclosure. The MEPT control process 700 can be implemented by means of the control unit 40 and the PtH plant 100, and thus the various features described above with reference to the control unit 40 and the PtH plant 100 are also applicable to the MEPT control process 700. In the MEPT control process 700, the energy input to the PtH plant 100 is distributed between the electrolyzer 10 and the pump 31 using the electrolyzer model 411 and the pump model 412 to achieve the maximum efficiency point of the PtH plant 100.

[0057] refer to Figure 7 In block 702, the sensing unit 50 directly or indirectly measures the states of the electrolyzer 10 and the pump 31 and generates measured parameters. Examples of measured parameters can refer to the above related descriptions.

[0058] At block 704, the control unit 40 receives the measured parameters.

[0059] At block 706, the control unit 40 inputs the measured parameters into the electrolyzer model 411 and the pump model 412. For example, parameters related to the electrochemical reaction are input into the electrolyzer model 411, and parameters related to the two-phase flow are input into the pump model 412.

[0060] At block 708 , the control unit 40 calculates the MEPT by solving the objective function using the electrolyzer model 411 and the pump model 412 .

[0061] At block 710 , the control unit 40 determines one or more set points for the coordinated operation of the electrolyzer 10 and the pump 31 based on the solution obtained by solving the objective function.

[0062] In one example, the electrolyzer model 411 and the pump model 412 perform coordinated processing and output one or more set points including a reference speed of the pump 31 and at least one of a reference power, a reference voltage, and a reference current of the power supply unit 20 .

[0063] In this example, the co-processing includes an optimization (Optimization_1) of the power distribution between the power supplied to the electrolyzer 10 and the power consumed by the pump 31. The optimization is performed on the basis of taking into account the above-mentioned bubble detachment. For example, the co-processing is performed using a trade-off algorithm to distribute power between the electrolyzer 10 and the pump 31. The trade-off algorithm includes the rule that an improved flow rate of the electrolyte will mitigate the bubble effect by accelerating the bubble detachment on the electrode, but the energy consumption of the pump will increase at the same time.

[0064] At block 712 , the control unit 40 provides the determined one or more set points to the power supply unit 20 and the pump 31 .

[0065] At block 714, the power supply unit 20 receives a set point including at least one of a reference power, a reference voltage, and a reference current, and supplies power to the electrolyzer according to the received set point. For example, the power supply controller controls the power supply unit to supply power to the electrolyzer at the reference power.

[0066] At block 716, the pump 31 receives a set point including a reference speed and pumps electrolyte into the electrolyzer according to the received set point. For example, the pump controller controls the pump to pump electrolyte into the electrolyzer at the reference speed.

[0067] At block 718, the control unit 40 calculates updates to the electrolyzer model 411 and the pump model 412. In one example, the updates include updates to the coefficients and / or constants of the electrolyzer model 411 and updates to the coefficients and / or constants of the pump model 412.

[0068] Figure 8is a flow chart of a MEPT control process 800 according to another example of the present disclosure. The MEPT control process 800 can be implemented by means of the control unit 40 and the PtH plant 100, so the various features described above with reference to the control unit 40 and the PtH plant 100 are also applicable to the MEPT control process 800. In the MEPT control process 800, the energy input to the PtH plant 100 is distributed among the electrolyzer 10, the pump 31 and the heater 32 using the electrolyzer model 411, the pump model 412 and the heater model 413 to achieve the maximum efficiency point of the PtH plant 100.

[0069] refer to Figure 8 In block 802, the sensing unit 50 directly or indirectly measures the states of the electrolyzer 10, the pump 31, and the heater 32, and generates measured parameters. Examples of the measured parameters can refer to the above related descriptions.

[0070] At block 804, the control unit 40 receives the measured parameters.

[0071] At block 806, the control unit 40 inputs the measured parameters into the electrolyzer model 411, the pump model 412, and the heater model 413. For example, parameters related to the electrochemical reaction are input into the electrolyzer model 411, parameters related to the two-phase flow are input into the pump model 412, and parameters related to the temperature dependency are input into the heater model 413.

[0072] At block 808 , the control unit 40 calculates the MEPT by solving the objective function using the electrolyzer model 411 , the pump model 412 , and the heater model 413 .

[0073] At block 810 , the control unit 40 determines one or more set points for coordinated operation of the electrolyzer 10 , the pump 31 , and the heater 32 based on the solution obtained by solving the objective function.

[0074] In one example, the electrolyzer model 411, the pump model 412, and the heater model 413 perform collaborative processing and output one or more set points, which include a reference speed of the pump 31, at least one of a reference power, a reference voltage, and a reference current of the power supply unit 20, and a reference temperature of the heater 32.

[0075] In this example, in addition to the above-mentioned optimization (Optimization_1), the co-processing also includes another optimization (Optimization_2) of the power distribution between the power supplied to the electrolyzer 10 and the power consumed by the heater 32. This optimization is performed on the basis of considering the above-mentioned thermodynamic points. For example, the co-processing is performed using a trade-off algorithm to distribute power between the electrolyzer 10 and the heater 32. The trade-off algorithm includes the rule that a higher temperature tends to better activate the electrode and thermodynamically benefit the reaction, at the expense of higher energy consumption in the heater 32.

[0076] Fig. 9 Two examples of optimization of power allocation are shown. Fig. 9 As shown, the maximum efficiency point η m It is implemented based on two optimizations, namely Optimaization_1 and Optimaization_2.

[0077] At block 812 , the control unit 40 provides the determined one or more set points to the power unit 20 , the pump 31 , and the heater 32 .

[0078] At block 814, the power supply unit 20 receives a set point including at least one of a reference power, a reference voltage, and a reference current, and supplies power to the electrolyzer according to the received set point. For example, the power supply controller controls the power supply unit to supply power to the electrolyzer at the reference power.

[0079] At block 816, the pump 31 receives a set point including a reference speed and pumps electrolyte into the electrolyzer according to the received set point. For example, the pump controller controls the pump to pump electrolyte into the electrolyzer at the reference speed.

[0080] At block 818, the heater 32 receives a set point including a reference temperature and adjusts the temperature of the electrolyte according to the received set point. For example, the heater controller controls the heater to adjust the temperature to the reference temperature.

[0081] At block 820, the control unit 40 calculates updates for the electrolyzer model 411, the pump model 412, and the heater model 413. In one example, the updates include updates for the coefficients and / or constants of the electrolyzer model 411, updates for the coefficients and / or constants of the pump model 412, and updates for the coefficients and / or constants of the heater model 413.

[0082] It should be noted that various modifications to power distribution may be implemented in a manner similar to that described above, such as power distribution between electrolyzers, pumps and coolers, power distribution between electrolyzers and heaters / coolers, and power distribution between electrolyzers, pumps, coolers and heat exchangers.

[0083] Fig.10Shows Figure 4 Implementation of PtH 100. Fig.10 As shown, the electrolyzer 10 includes a group of electrolysis units 10a-10c, each of which is coupled to and powered by a power source 21. The pump 31 includes a plurality of pumps 31a-31b arranged in the flow path of the electrolyte. The cooler 33 includes a plurality of coolers 33a-33b arranged in the flow path. Water is electrolyzed to produce hydrogen and oxygen.

[0084] Fig.11 Shows Figure 4 Another embodiment of the PtH 100. Fig.11 As shown, the power supply 21 includes a group of power supplies 21a-21c, and the electrolyzer 10 includes a group of electrolysis units 10a-10c. Each electrolysis unit is coupled to and powered by a corresponding power supply. For example, the electrolysis unit 10a is coupled to and powered by the power supply 21a; the electrolysis unit 10b is coupled to and powered by the power supply 21b; the electrolysis unit 10c is coupled to and powered by the power supply 21c. The pump 31 includes a plurality of pumps 31a-31e arranged in the flow path of the electrolyte. A cooler 33a is arranged in the flow path. The heat exchanger 34 includes a plurality of heat exchangers 34a-34c arranged in the flow path. The alkali solution is electrolyzed to produce hydrogen and oxygen.

[0085] It should be noted that according to Fig.10 and 11 The above configuration of the PtH factory 100 is only exemplary, and the PtH factory 100 may also be implemented in other various configurations with adaptive modifications. These changes and modifications are within the scope of the present disclosure.

[0086] Fig.12 1 is a flow chart of a control method 1200 for a PtH plant according to an example of the present disclosure. The method 1200 may be implemented by means of the control unit 40 , so the various features described above with reference to the control unit 40 are also applicable to the method 1200 .

[0087] refer to Fig.12 In step S1202, the control unit calculates the maximum efficiency point tracking of the PtH plant by solving an objective function with a predetermined hydrogen production rate of the PtH plant or a predetermined amount of energy input to the PtH plant using at least one model. The control unit 40 receives measured parameters indicating the status of components of the PtH plant as inputs to the at least one model.

[0088] In step S1204 , the control unit determines one or more set points for coordinated operation of the components of the PtH plant based on the solution obtained by solving the objective function.

[0089] In step S1206 , the control unit 40 provides one or more set points to one or more of the components of the PtH plant to operate the PtH at a maximum efficiency point.

[0090] The present disclosure also provides a non-transitory computer-readable medium including MEPT instructions stored in a memory and executed by a processor to perform any operation of the method 1200 for MEPT control of a PtH plant according to the above example.

[0091] In one example, at least one model 41 is implemented as a multi-physics model with the above variables and constants. An example and constraints of a multi-physics model are described below, where the electrolyzer has been divided into n sections in the y direction, and the variables are assumed to be constant within the sections. The definition of parameters (e.g., variables and constants) can refer to Table 3 below. Electrochemical reaction confinement U cell =U rev +U act,k +U ohm,k (3) 1.23(V)≤U cell (7) Two-phase flow constraints Temperature Dependence Constraints 298.15(K)≤T≤368.15(K) (16) Table 3

[0092] The proposed MEPT control can be verified by simulation results. Fig.13 is a simulation graph showing the synergy of temperature and speed for maximum PtH efficiency. Fig.13 It shows that there is synergy between the pump, the heater and the electrolyzer. Through the synergy between the pump and the heater, the optimal operating parameters can be obtained at the maximum efficiency point MP.

[0093] Fig.14 and 15 Such simulations are shown to be applicable to large industrial units (e.g., large industrial electrolyzers) as well as small industrial units (e.g., small industrial electrolyzers). Fig.14 and 15 In , coordinate axes without specific values ​​are shown. The value of each axis increases along the axis within a range corresponding to the scenario to which it is applied. For example, in Fig.14The simulation is applied to a scenario of a small industrial unit, with the values ​​along the horizontal axis increasing from 1A to 10A. Fig.14 In the case of a simulation applied to a large industrial unit, the values ​​of the horizontal axis increase along the horizontal axis and go from 1000A to 5000A.

[0094] Fig.14 is a simulation diagram showing the maximum efficiency and optimized power of the pump, heater and electrolyzer at different supply currents. Fig.14 As shown, the maximum efficiency point of a power-to-hydrogen plant can be tracked with different supply currents. This is particularly applicable to PtH plants that obtain energy from fluctuating renewable energy sources.

[0095] Fig.15 is the efficiency as the supply current fluctuates ( Fig.15 (a)), temperature( Fig.15 (b)), speed( Fig.15 (c)) and voltage ( Fig.15 (d) is a simulation diagram of the maximum efficiency point, where the solid line represents MEPT control and the dashed line represents the predetermined value used as a control example. It can be seen that MEPT control can also be applied to scenarios that require dynamic supply current. Fig.15 (a) shows that the model can be used to obtain the optimal efficiency and operating parameters of the PtH plant in time when the supply current fluctuates. Fig.15 (b) and (c) are the optimal temperature and speed of the electrolyte. Compared with the control case represented by the dashed line, the optimal temperature and speed deviate the most from the control case of the dashed line when the supply current is low, which can help explain Fig.15 The highest improvement in efficiency is shown in (a).

[0096] It should be noted that all the above operations are merely exemplary, and the present disclosure is not limited to any operation or the order of these operations, and should cover all other equivalent solutions under the same or similar concepts.

[0097] Processors are described in conjunction with various systems and methods. These processors can be implemented using electronic hardware, computer software or any combination thereof. Whether these processors are implemented as hardware or software will depend on specific applications and the overall design constraints imposed on the system. As an example, the processor provided in this disclosure, any part of the processor, or any combination of processors can be implemented as a microprocessor, a microcontroller, a digital signal processor (DSP), a field programmable gate array (FPGA), a programmable logic device (PLD), a state machine, a gate logic, a discrete hardware circuit system, and other suitable processing components configured to perform the various functions described in this disclosure. The function of the processor provided in this disclosure, any part of the processor, or any combination of processors can be implemented as software performed by a microprocessor, a microcontroller, a DSP or other suitable platforms.

[0098] The foregoing description is provided to enable any person skilled in the art to practice the various aspects described herein. Various modifications to these aspects will be apparent to those skilled in the art, and the general principles defined herein may be applied to other aspects. Therefore, the claims are not intended to be limited to the aspects shown herein. All structural and functional equivalents of the elements of various aspects of the present disclosure that are known or apparent to those skilled in the art are intended to be covered by the claims.

Claims

1. A control unit (40) for a power-to-hydrogen (PtH) plant (100), the control unit (40) comprising at least one model (41) and being configured to: The maximum efficiency point tracking of the PtH plant is calculated by solving an objective function with a predetermined hydrogen production rate of the PtH plant or a predetermined amount of energy input to the PtH plant using the at least one model, wherein, The control unit receives, as input to the at least one model, measured parameters indicative of states of components of the PtH plant; determining one or more set points for coordinated operation of the components of the PtH plant based on a solution obtained by solving the objective function; as well as The one or more set points are provided to one or more of the components of the PtH plant to operate the PtH at the maximum efficiency point.

2. The control unit (40) according to claim 1, wherein: The objective function comprises a maximum ratio corresponding to the maximum efficiency point of the PtH plant, and The maximum ratio is a ratio of the hydrogen energy corresponding to the predetermined hydrogen production rate to the minimum energy amount required by the PtH plant, or a ratio of the maximum amount of hydrogen energy generated by the PtH plant to the predetermined energy amount input to the PtH plant.

3. The control unit (40) according to any one of claims 2-3, wherein: The components of the PtH plant include an electrolyzer (10), an auxiliary device (30) coupled to the electrolyzer, and a power supply unit (20) for supplying power to the electrolyzer and the auxiliary device, and the auxiliary device includes a pump (31), and at least one of a heater (32), a cooler (33), and a heat exchanger (34); and Wherein, the one or more set points include one or more of the following reference values, and the components of the PtH plant are cooperatively controlled based on the corresponding reference values: - a reference current of the power supply unit; - a reference voltage of the power supply unit; - a reference power of the power supply unit; - a reference temperature of at least one of the heater, the cooler and the heat exchanger, and - The reference speed of the pump.

4. The control unit (40) according to claim 3, wherein: The at least one model (41) includes a collaborative processing model for collaborative operation of the components; and Wherein, the collaborative processing model includes an electrolyzer model and a pump model, and optionally, the collaborative processing model also includes one or more of a heater model, a cooler model and a heat exchanger model.

5. The control unit (40) according to claim 4, wherein: Determining the one or more set points comprises: At the co-processing model, the power distribution of energy input to the PtH plant between power supplied to the electrolyser and power consumed by the auxiliary equipment is calculated.

6. The control unit (40) according to claim 5, wherein: Calculating the power distribution comprises calculating, at the electrolyser model and the pump model, an optimization of the power distribution between power supplied to the electrolyser and power consumed by the pump, and optionally the optimization is associated with bubble detachment in the electrolyser.

7. The control unit (40) according to claim 5, wherein: Calculating the power distribution includes: calculating, at the electrolyzer model and one or more of the heater model, the cooler model and the heat exchanger model, an optimization of the power distribution between the power supplied to the electrolyzer and the power consumed by one or more of the heater, the cooler and the heat exchanger, and optionally, the optimization is associated with thermodynamically promoting the reaction in the electrolyzer.

8. The control unit (40) according to claim 3, wherein: The measured parameters are variables of the at least one model and include parameters related to electrochemical reactions, two-phase flow and temperature dependence of the electrolyzer, And optionally, the measured parameters also include parameters related to the operating state of the auxiliary device.

9. The control unit (40) according to claim 1, wherein: The measured parameters include: - the current in the electrolyser; - the voltage across the electrolyser; - the velocity of the electrolyte in the electrolyser; and - The temperature of the electrolyte in the electrolyser.

10. The control unit (40) according to any one of claims 1 to 9, wherein: The control unit is further configured to: calculating an update to the at least one model based on the measured parameters; And optionally, said updating of said at least one model comprises updating of coefficients and / or constants of said at least one model.

11. A PtH plant (100), comprising: an electrolyzer (10) for producing hydrogen; an auxiliary device (30), the auxiliary device being coupled to the electrolyzer; a power supply unit (20), the power supply unit being used to supply power to the electrolyzer (10) and the auxiliary equipment (30); as well as A control unit (40) communicating with the electrolyser (10), the power supply unit (20) and the auxiliary device (30), the control unit (40) comprising at least one model (41) and being configured to: calculating a maximum efficiency point tracking of the PtH plant (100) by solving an objective function with a predetermined hydrogen production rate of the electrolyser or a predetermined amount of energy input to the PtH plant using the at least one model, wherein the control unit receives measured parameters indicative of states of components of the PtH plant as input to the at least one model; determining one or more set points for coordinated operation of the components of the PtH plant based on a solution obtained by solving the objective function; and The one or more set points are provided to one or more of the components of the PtH plant to operate the PtH at the maximum efficiency point.

12. The PtH plant (100) according to claim 11, wherein The power supply unit includes a power supply, and the electrolyzer includes a group of electrolysis cells, each electrolysis cell is coupled to and powered by the power supply.

13. The PtH plant (100) according to claim 11, wherein: The power supply unit includes a set of power supplies, and the electrolyzer includes a set of electrolysis cells, each electrolysis cell being coupled to and powered by a corresponding power supply of the power supplies.

14. The PtH plant (100) according to any one of claims 11 to 13, wherein: The auxiliary equipment (30) includes a pump (31), and at least one of a heater (32), a cooler (33) and a heat exchanger (34), and wherein the pump is configured to pump electrolyte into the electrolyzer based on a set point corresponding to a reference speed, and Wherein at least one of the heater, the cooler, and the heat exchanger is configured to adjust the temperature of the electrolyte based on a set point corresponding to a reference temperature.

15. The PtH plant (100) according to any one of claims 11 to 14, wherein: The power supply unit includes one or more power supplies and one or more converters, and Wherein the power supply unit is configured to supply power to the electrolyzer based on a set point corresponding to at least one of a reference current, a reference voltage, and a reference power.

16. The PtH plant (100) according to any one of claims 11 to 15, wherein: The auxiliary equipment (30) is integrated with the electrolyzer (10).

17. The PtH plant (100) according to any one of claims 11-16, further comprising a sensing unit (50), the sensing unit being configured to measure the states of the electrolyser (10), the power supply unit (20) and the auxiliary equipment (30), and to generate the measured parameters.

18. A control method for a power-to-hydrogen (PtH) plant (100), comprising: calculating a maximum efficiency point tracking of the PtH plant by solving an objective function with a predetermined hydrogen production rate of the PtH plant or a predetermined amount of energy input to the PtH plant using at least one model, wherein a control unit receives measured parameters indicative of states of components of the PtH plant as inputs to the at least one model; determining one or more set points for coordinated operation of the components of the PtH plant based on a solution obtained by solving the objective function; and The one or more set points are provided to one or more of the components of the PtH plant to operate the PtH at the maximum efficiency point.

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