A method and system for load control of a hydrogen fuel cell system

Abstract

The application discloses a loading control method and system for a hydrogen fuel cell system, and the method comprises the following steps: receiving a loading instruction of the hydrogen fuel cell system, and acquiring a real-time stack current value, a target loading stack current value, a real-time air compressor rotating speed, a target air compressor rotating speed, a current loading rate and an air compressor acceleration time of the hydrogen fuel cell system according to the loading instruction, so as to acquire a current loading time length and an air compressor rotating speed loading time length of the hydrogen fuel cell system; determining a stack current loading time of the hydrogen fuel cell system according to the air compressor rotating speed loading time length, the current loading time length and the air compressor acceleration time; and realizing loading control of the hydrogen fuel cell system according to the air compressor acceleration time, the stack current loading time, the target loading stack current value and the target air compressor rotating speed, so as to improve the operation performance of the hydrogen fuel cell.

Description

Technical Field

[0001] This invention relates to the field of hydrogen fuel cell technology, and specifically to a loading control method and system for a hydrogen fuel cell system. Background Technology

[0002] A hydrogen fuel cell is an energy conversion device that directly converts the chemical energy of hydrogen and oxygen into electrical energy through an electrochemical reaction. A complete hydrogen fuel cell system consists of a hydrogen fuel cell stack as its core, along with a gas supply system, a cooling system, and an electronic control system. Currently, this system has been demonstrated in transportation vehicles such as buses and logistics vehicles, but its large-scale commercialization is still limited by further improvements in system lifespan and performance. Among these, achieving precise matching between the stack current loading rate and the airflow change rate during vehicle load variations (especially rapid loading) is one of the key factors affecting system performance and lifespan.

[0003] Current hydrogen fuel cell systems typically employ a control strategy based on a fixed lead time for rapid loading. Specifically, the system determines the load current to be varied based on the target current and the current, and obtains the target air compressor speed using a pre-calibrated current-speed lookup table. During control, the air compressor first accelerates at a fixed rate of change, followed by the fuel cell stack current loading with a fixed lag time, thus forming a "compressor first, stack later" loading sequence. This method can provide a basic excess air guarantee for the fuel cell stack under certain conditions.

[0004] However, the aforementioned fixed lead time control method has significant shortcomings when hydrogen fuel cell systems face rapid loading demands. First, if the loading rate is too high, the air flow supplied by the air compressor cannot match the oxygen consumption rate required by the fuel cell stack in time, resulting in insufficient oxygen concentration at the electrochemical reaction interface. This leads to a decrease in the average output voltage, increased fluctuations, deterioration of system output performance, and prolonged recovery time. Second, a severe shortage of oxygen at the reaction interface may trigger "cathode starvation," leading to localized overheating. In extreme cases, this could damage the membrane electrode assembly (MEA) and shorten the fuel cell's lifespan. Summary of the Invention

[0005] This invention discloses a loading control method and system for hydrogen fuel cell systems, which is used to improve the operating performance of hydrogen fuel cells.

[0006] To achieve the above objectives, the present invention discloses a loading control method for a hydrogen fuel cell system, comprising: Receive loading instructions from the hydrogen fuel cell system, and obtain the real-time stack current value, target loading stack current value, real-time air compressor speed, and target air compressor speed of the hydrogen fuel cell system according to the loading instructions; The current loading rate and air compressor acceleration time of the hydrogen fuel cell system are matched according to the loading command; The current loading duration of the hydrogen fuel cell system is obtained based on the real-time stack current value, the target loaded stack current value, and the current loading rate; and the air compressor speed loading duration of the hydrogen fuel cell system is determined based on the real-time air compressor speed and the target air compressor speed. The stack current loading time of the hydrogen fuel cell system is determined based on the air compressor speed loading time, the current loading time, and the air compressor acceleration time. The loading control of the hydrogen fuel cell system is achieved based on the air compressor acceleration time, the stack current loading time, the target loaded stack current value, and the target air compressor speed.

[0007] This invention discloses a loading control method for a hydrogen fuel cell system. By dynamically coordinating the timing of air compressor speed loading and fuel cell stack current loading, it ensures that the air flow can promptly match the oxygen demand of the fuel cell stack during rapid loading of the hydrogen fuel cell system. This effectively avoids problems such as output voltage drop, increased fluctuations, system performance deterioration, and prolonged recovery time caused by insufficient oxygen concentration. It also prevents cathode starvation from damaging the membrane electrode assembly, thereby improving the operating performance of the fuel cell system.

[0008] As a preferred example, receiving the loading command of the hydrogen fuel cell system and obtaining the real-time stack current value, target loading stack current value, real-time air compressor speed, and target air compressor speed of the hydrogen fuel cell system according to the loading command includes: The real-time stack current value and the target loading stack current value of the hydrogen fuel cell system are obtained according to the loading command of the hydrogen fuel cell system. The real-time air compressor speed of the hydrogen fuel cell system is obtained by querying a pre-built current-speed mapping table based on the real-time stack current value. The target air compressor speed of the hydrogen fuel cell system is obtained by querying the current-speed mapping table based on the target loaded stack current value.

[0009] The above scheme, based on a mapping table lookup mechanism, ensures a precise correspondence between air compressor speed data and fuel cell stack current requirements. Therefore, in subsequent loading control calculations, such as determining the current loading duration and air compressor speed loading duration, more accurate and reliable input parameters can be obtained. This significantly improves the matching accuracy between oxygen supply and fuel cell stack oxygen consumption rate during loading, effectively avoiding problems such as cathode starvation, output voltage drop, and system performance degradation caused by insufficient oxygen. This ensures the stability and reliability of the hydrogen fuel cell system during rapid loading and helps extend its service life.

[0010] As a preferred example, the step of matching the current loading rate and air compressor acceleration time of the hydrogen fuel cell system according to the loading command includes: Extract the loading power and air compressor acceleration time of the hydrogen fuel cell system from the loading command; The current loading rate of the hydrogen fuel cell system is obtained by querying a preset current loading rate library based on the loaded power; wherein, the current loading rate library includes the lowest current rate, the medium current rate, and the highest current rate.

[0011] The above scheme dynamically selects a current loading rate that matches the current loading requirement by querying a preset current loading rate library based on the loaded power, rather than using a single fixed rate. The current loading rate library provides multiple options, including minimum, medium, and maximum current rates, allowing the system to flexibly select the most suitable loading speed according to the magnitude of the loaded power. This adaptive current loading rate matching mechanism effectively solves the problem of mismatch between the stack current loading rate and the air compressor speed change rate under traditional fixed-rate control. It ensures that the stack receives sufficient oxygen supply under different loading requirements, thereby maintaining a stable electrochemical reaction and avoiding performance degradation phenomena such as output voltage drop and increased fluctuations due to insufficient oxygen supply. It also effectively prevents localized overheating and membrane electrode damage caused by cathode starvation, thus improving the overall performance and service life of the hydrogen fuel cell system.

[0012] As a preferred example, the step of obtaining the current loading duration of the hydrogen fuel cell system based on the real-time stack current value, the target loaded stack current value, and the current loading rate, and determining the air compressor speed loading duration of the hydrogen fuel cell system based on the real-time air compressor speed and the target air compressor speed, includes: The current difference between the target loaded stack current value and the real-time stack current value is obtained, and the current difference is used as the current loading amplitude of the hydrogen fuel cell system. The speed difference between the target air compressor speed and the real-time air compressor speed is obtained, and the speed difference is used as the speed loading amplitude of the hydrogen fuel cell system. The ratio of the speed loading amplitude to the preset air compressor speed increase rate is obtained, and the speed ratio is used as the air compressor speed loading duration of the hydrogen fuel cell system. When the current loading rate is the minimum current rate, a first ratio of the current loading amplitude to the minimum current rate is obtained, and the first ratio is used as the current loading duration of the hydrogen fuel cell system. When the current loading rate is the medium current rate, a second ratio of the current loading amplitude to the medium current rate is obtained, and the second ratio is used as the current loading duration of the hydrogen fuel cell system. When the current loading rate is the highest current rate, a third ratio of the current loading amplitude to the highest current rate is obtained, and the third ratio is used as the current loading duration of the hydrogen fuel cell system.

[0013] The aforementioned scheme uses the precise difference between the target loaded stack current value and the real-time stack current value as the current loading amplitude, and the difference between the target air compressor speed and the real-time air compressor speed as the speed loading amplitude. This provides an accurate quantitative basis for subsequent duration calculations. Based on this, the speed loading amplitude is compared with a preset air compressor speed increase rate to dynamically determine the air compressor speed loading duration, avoiding the limitations of a fixed advance time strategy. Furthermore, this application calculates the ratio of the current loading amplitude to the corresponding rate based on different current loading rates (including minimum, medium, and maximum current rates) to obtain a precise current loading duration. This mechanism of adaptively adjusting the current loading duration according to the actual loading rate ensures that the stack current loading rate matches the air compressor's gas supply capacity under various loading requirements. Therefore, the duration calculation method proposed in this application can significantly improve the accuracy of oxygen supply in the dynamic loading process of the hydrogen fuel cell system, effectively prevent the occurrence of "cathode starvation" in the stack, thereby ensuring stable stack operation, extending its service life, and improving the overall system performance.

[0014] As a preferred example, determining the stack current loading time of the hydrogen fuel cell system based on the air compressor speed loading time, the current loading time, and the air compressor acceleration time includes: When the current loading rate is the minimum current rate, the first difference between the air compressor speed loading time and the first ratio is obtained, and the first difference is used as the first air compressor early start time of the hydrogen fuel cell system. The acceleration time of the air compressor is added to the advance start time of the first air compressor to obtain the stack current loading time of the hydrogen fuel cell system.

[0015] The above scheme establishes a dynamic and precise lead time between the compressor's rotational speed loading time and the current loading time at the lowest current rate (a first ratio), using this difference as the advance start-up time for the first compressor. Based on this, the compressor's start-up time is added to the advance start-up time of the first compressor to accurately determine the stack current loading time. This precise timing control avoids problems such as oxygen excess and energy waste due to premature compressor start-up at the lowest current rate, or insufficient oxygen supply and cathode starvation due to delayed start-up. Overall, this scheme effectively improves the performance stability, response efficiency, and lifespan of the hydrogen fuel cell system under low-speed loading conditions, ensuring coordinated operation of the system at different loading rates.

[0016] As a preferred example, determining the stack current loading time of the hydrogen fuel cell system based on the air compressor speed loading time, the current loading time, and the air compressor acceleration time includes: When the current loading rate is a medium current rate, obtain the first sum of the first air compressor early start time and the second ratio; Obtain the second difference between the air compressor speed loading time and the first sum, and use the second difference as the advance start time of the second air compressor of the hydrogen fuel cell system; The acceleration time of the air compressor is added to the advance start time of the second air compressor to obtain the stack current loading time of the hydrogen fuel cell system.

[0017] The above scheme provides a more comprehensive reference for subsequent calculations of the advance start-up time by comprehensively considering the sum of the first compressor's advance start-up time (as a basic advance amount) and the second ratio (reflecting the time required for moderate current loading). Based on this, the compressor speed loading time is compared with this comprehensive reference value to obtain a second difference, which is then used as the second compressor's advance start-up time, achieving dynamic optimization and precise adjustment of the compressor's advance start-up time. Finally, the compressor start-up time is added to the optimized second compressor advance start-up time to obtain the stack current loading time, ensuring a high degree of timing matching between the stack current loading and the compressor's gas supply. This precise loading control avoids the potential mismatch between oxygen supply and stack demand at moderate loading rates, effectively preventing cathode starvation, thus ensuring stable output performance of the hydrogen fuel cell system during rapid loading and extending system lifespan.

[0018] As a preferred example, determining the stack current loading time of the hydrogen fuel cell system based on the air compressor speed loading time, the current loading time, and the air compressor acceleration time includes: When the current loading rate is the highest current rate, obtain the second sum of the early start time of the second air compressor, the early start time of the first air compressor, and the second ratio; Obtain the third difference between the air compressor speed loading time and the second sum, and use the third difference as the advance start time of the third air compressor of the hydrogen fuel cell system; The acceleration time of the air compressor is added to the advance start time of the third air compressor to obtain the stack current loading time of the hydrogen fuel cell system.

[0019] At the highest current rate, this application can fully utilize historical or preset parameters at different loading rates to establish a more comprehensive and accurate basis for advance calculation, avoiding deviations that may arise from calculations based on a single parameter. Based on this, by finely adjusting the advance start-up time of the air compressor, it ensures that the air compressor has sufficient time to increase its speed to the required level before the fuel cell stack current begins loading, thereby effectively guaranteeing the oxygen supply required by the fuel cell stack during rapid loading. This precise timing matching mechanism allows the loading of the fuel cell stack current to be highly synchronized with the air compressor's air supply capacity, avoiding problems such as cathode starvation, voltage drop, and system performance deterioration caused by air compressor supply lag, significantly improving the operational stability, efficiency, and lifespan of the hydrogen fuel cell system under rapid loading conditions.

[0020] As a preferred example, the step of implementing loading control of the hydrogen fuel cell system based on the air compressor acceleration time, the stack current loading time, the target loaded stack current value, and the target air compressor speed includes: The air compressor of the hydrogen fuel cell system is controlled to accelerate according to the air compressor acceleration time and the preset air compressor speed increase rate, and the air compressor speed is acquired in real time. The current loading of the hydrogen fuel cell system is controlled according to the current loading time and the current loading rate, and the current of the fuel cell is acquired in real time. When the rotational speed reaches the target air compressor speed and the current reaches the target loading stack current value, the loading control of the hydrogen fuel cell system is completed.

[0021] The above scheme continuously monitors the real-time air compressor speed and fuel cell stack current, and uses a dual-condition judgment (i.e., the air compressor speed reaches the target air compressor speed and the fuel cell stack current reaches the target loading current value) as the completion mark for loading control. This ensures that the air compressor can always provide a sufficient oxygen supply throughout the loading process, precisely matching the oxygen consumption rate of the fuel cell stack, thereby significantly reducing the risk of insufficient oxygen supply. Therefore, it can effectively suppress the decrease in the average output voltage and the increase in fluctuations, improve the system's output performance, shorten the recovery time, and fundamentally avoid local overheating and membrane electrode damage caused by "cathode starvation," thus extending the service life of the hydrogen fuel cell system and improving its reliability and stability.

[0022] On the other hand, the present invention discloses a loading control system for a hydrogen fuel cell system, including an instruction loading module, a data matching module, a duration calculation module, a time determination module, and a loading control module; The instruction loading module is used to receive the loading instruction of the hydrogen fuel cell system, and to obtain the real-time stack current value, the target loading stack current value, the real-time air compressor speed and the target air compressor speed of the hydrogen fuel cell system according to the loading instruction. The data matching module is used to match the current loading rate and air compressor acceleration time of the hydrogen fuel cell system according to the loading command. The duration calculation module is used to obtain the current loading duration of the hydrogen fuel cell system based on the real-time stack current value, the target loaded stack current value and the current loading rate, and to determine the air compressor speed loading duration of the hydrogen fuel cell system based on the real-time air compressor speed and the target air compressor speed. The timing determination module is used to determine the stack current loading time of the hydrogen fuel cell system based on the air compressor speed loading time, the current loading time, and the air compressor acceleration time. The loading control module is used to control the loading of the hydrogen fuel cell system based on the air compressor acceleration time, the stack current loading time, the target stack current value, and the target air compressor speed.

[0023] This invention discloses a loading control system for a hydrogen fuel cell system. By dynamically coordinating the timing of air compressor speed loading and stack current loading, it ensures that the air flow can promptly match the oxygen demand of the fuel cell stack during rapid loading of the hydrogen fuel cell system. This effectively avoids problems such as output voltage drop, increased fluctuations, system performance deterioration, and prolonged recovery time caused by insufficient oxygen concentration. It also prevents cathode starvation from damaging the membrane electrode assembly, thereby improving the operating performance of the fuel cell system.

[0024] As a preferred example, the instruction loading module includes a current unit and a speed unit; The current unit is used to obtain the real-time stack current value and the target loading stack current value of the hydrogen fuel cell system according to the loading command of the hydrogen fuel cell system. The speed unit is used to query a pre-built current-speed mapping table based on the real-time stack current value to obtain the real-time air compressor speed of the hydrogen fuel cell system; and to query the current-speed mapping table based on the target loaded stack current value to obtain the target air compressor speed of the hydrogen fuel cell system.

[0025] The above scheme, based on a mapping table lookup mechanism, ensures a precise correspondence between air compressor speed data and fuel cell stack current requirements. Therefore, in subsequent loading control calculations, such as determining the current loading duration and air compressor speed loading duration, more accurate and reliable input parameters can be obtained. This significantly improves the matching accuracy between oxygen supply and fuel cell stack oxygen consumption rate during loading, effectively avoiding problems such as cathode starvation, output voltage drop, and system performance degradation caused by insufficient oxygen. This ensures the stability and reliability of the hydrogen fuel cell system during rapid loading and helps extend its service life. Attached Figure Description

[0026] To more clearly illustrate the technical solution of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0027] Figure 1 This is a schematic flowchart of a loading control method for a hydrogen fuel cell system disclosed in an embodiment of the present invention; Figure 2 This is a schematic diagram of the structure of a hydrogen fuel cell system disclosed in an embodiment of the present invention; Figure 3 This is a schematic diagram illustrating the principle of an airflow control method during the loading process of a hydrogen fuel cell system disclosed in an embodiment of the present invention. Figure 4 This is a schematic diagram of a loading control system for a hydrogen fuel cell system disclosed in an embodiment of the present invention. Detailed Implementation

[0028] 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.

[0029] Reference Figure 1 To improve the operating performance of hydrogen fuel cell systems, this embodiment discloses a loading control method for hydrogen fuel cell systems, mainly including: Step 101: Receive the loading command of the hydrogen fuel cell system, and obtain the real-time stack current value, target loading stack current value, real-time air compressor speed and target air compressor speed of the hydrogen fuel cell system according to the loading command.

[0030] Step 102: Match the current loading rate and air compressor acceleration time of the hydrogen fuel cell system according to the loading command; Step 103: Obtain the current loading duration of the hydrogen fuel cell system based on the real-time stack current value, the target loaded stack current value, and the current loading rate; and determine the air compressor speed loading duration of the hydrogen fuel cell system based on the real-time air compressor speed and the target air compressor speed. Step 104: Determine the stack current loading time of the hydrogen fuel cell system based on the air compressor speed loading time, the current loading time, and the air compressor acceleration time. Step 105: Implement the loading control of the hydrogen fuel cell system based on the air compressor acceleration time, the stack current loading time, the target loaded stack current value, and the target air compressor speed.

[0031] In this embodiment, the target loaded stack current value refers to the final current output value that the hydrogen fuel cell system stack needs to achieve according to the loading command; the real-time air compressor speed refers to the actual operating speed of the hydrogen fuel cell system air compressor when the loading command is received, reflecting the current air supply capacity; the target air compressor speed refers to the final operating speed that the air compressor needs to achieve according to the target loaded stack current value to ensure that the stack receives sufficient oxygen supply; the current loading rate refers to the rate at which the stack current changes with time from the real-time value to the target value, which affects the stack's response speed and oxygen consumption rate; the air compressor start-up time refers to the starting point at which the air compressor begins to increase its speed to increase airflow; the current loading duration refers to the time required for the stack current to be loaded from the real-time value to the target value; the air compressor speed loading duration refers to the time required for the air compressor speed to increase from the real-time value to the target value; and the stack current loading time refers to the starting point at which the stack begins to increase its current output.

[0032] In this embodiment, refer to Figure 2 As shown, the hydrogen fuel cell system used to carry out electrochemical reactions to generate electricity mainly includes an air filter, MFA1 (air mass flow meter), air compressor, intercooler, humidifier, muffler, TCV1 (electrically controlled air inlet valve of hydrogen fuel cell), TCV2 (electrically controlled air outlet valve of hydrogen fuel cell), and hydrogen fuel cell stack.

[0033] like Figure 2 In the hydrogen fuel cell system shown, during the generation of electricity, an air filter is used to perform physical and chemical filtration on the input air to ensure that the air entering the fuel cell meets the usage requirements, and then the filtered air is sent to the air compressor; the MFA1 is fixed on the pipeline connecting the air filter and the air compressor, and is used to measure the flow rate of the air entering the hydrogen fuel cell system. The acquired data is used to determine whether the hydrogen fuel cell stack lacks oxygen supply; the air compressor is used to provide air at a certain pressure and flow rate required for the hydrogen fuel cell reaction. The air compressor speed data fed back during operation is used to determine whether the hydrogen fuel cell stack lacks oxygen supply; and the intercooler is used to cool the inlet air of the hydrogen fuel cell to meet the reasonable supply air temperature requirements. It should be noted that the cooling subsystem used to stabilize the temperature of the fuel cell stack is connected to the intercooler to maintain heat exchange between the air and the coolant; the humidifier is used to humidify the inlet air of the hydrogen fuel cell to achieve the humidity level required for the reaction; during the actual operation of the hydrogen fuel cell system, TCV1 is kept fully open, while TCV2 is adjusted according to changes in operating conditions to ensure appropriate pressure in the air chamber; the muffler is a device used to reduce exhaust noise.

[0034] by Figure 2 Taking the hydrogen fuel cell system shown as an example, the working principle of a hydrogen fuel cell is as follows: When hydrogen enters the hydrogen inlet of the hydrogen fuel cell, it undergoes mass transfer in the bipolar plate hydrogen chamber via convection. At the membrane electrode assembly (MEA), it is transferred through the diffusion layer to the anode catalyst layer via diffusion mass transfer. Under the action of the catalyst, an electrochemical reaction occurs, in which hydrogen molecules react to generate positively charged protons and negatively charged electrons. The protons reach the cathode catalyst layer of the fuel cell stack via the proton exchange membrane through hydration, while the electrons reach the cathode catalyst layer through the external circuit. Simultaneously, when air enters the air inlet of the hydrogen fuel cell, it undergoes mass transfer in the bipolar plate air chamber via convection. At the MEA, it is transferred through the diffusion layer to the cathode catalyst layer via diffusion mass transfer. Under the action of the catalyst, an electrochemical reaction occurs, in which oxygen molecules, water, and protons and electrons react to generate water.

[0035] When the hydrogen fuel cell system receives a start command, on one hand, air, filtered through an air filter, enters the air compressor, which compresses the air. The air, now at a certain temperature and pressure, is then cooled by an intercooler before entering the air chamber inlet of the hydrogen fuel cell. The air pressure and flow rate at the inlet are regulated by the air compressor speed and the TCV2 valve. On the other hand, the aforementioned devices operate according to predetermined logic, adjusting hydrogen to the required pressure and supplying it to the hydrogen inlet of the fuel cell stack. After the air and hydrogen enter the hydrogen fuel cell system, an electrochemical reaction occurs, producing electrical energy, heat, and water as a byproduct. Upon receiving the start command, the cooling subsystem activates the water pump, circulating the coolant through the coolant inlet, outlet, and external heat dissipation circuit of the hydrogen fuel cell system, carrying away the reaction heat from the cell and maintaining the required reaction temperature.

[0036] The above steps, by dynamically coordinating the timing of air compressor speed loading and stack current loading, ensure that the airflow can promptly match the stack's oxygen demand during the rapid loading process of the hydrogen fuel cell system. This effectively avoids problems such as output voltage drop, increased fluctuations, system performance deterioration, and prolonged recovery time caused by insufficient oxygen concentration. It also prevents cathode starvation from damaging the membrane electrode assembly, thereby improving the operating performance of the fuel cell system.

[0037] In this embodiment, step 101 includes: Step 1011: Obtain the real-time stack current value and the target loading stack current value of the hydrogen fuel cell system according to the loading command of the hydrogen fuel cell system.

[0038] Step 1012: Query the pre-built current-speed mapping table based on the real-time stack current value to obtain the real-time air compressor speed of the hydrogen fuel cell system.

[0039] Step 1013: Query the current-speed mapping table based on the target loaded stack current value to obtain the target air compressor speed of the hydrogen fuel cell system.

[0040] In this embodiment, since the air compressor speed is directly proportional to the air flow rate in the air chamber of the hydrogen fuel cell system during the air compressor loading process, the specific method for controlling the air flow rate is as follows: Where: Q is the airflow rate in the air chamber of the fuel cell. The first proportionality coefficient, This refers to the rotational speed of the air compressor.

[0041] According to Faraday's law, the current in the fuel cell stack is directly proportional to the airflow, satisfying the following relationship: Where I is the stack current and k2 is the second proportionality coefficient. Therefore, during the operation of a hydrogen fuel cell system, the stack current is directly proportional to the air compressor speed.

[0042] In summary, based on the direct proportionality between the fuel cell stack current and the air compressor speed, a current-speed mapping table can be pre-constructed after obtaining the first and second proportionality coefficients through testing, representing the relationship between the fuel cell stack current and the air compressor speed. This current-speed mapping table can then be used to characterize the air compressor speed corresponding to different currents.

[0043] In this embodiment, after pre-constructing the current-speed mapping table, the system monitors in real time whether the hydrogen fuel cell system needs to be loaded. For example, when the driver needs to overtake, climb hills, or increase vehicle speed, requiring the hydrogen fuel cell system to provide higher electrical energy to support the increased vehicle speed, the accelerator pedal can be monitored in real time. When the accelerator pedal is detected to be depressed, a loading command for the hydrogen fuel cell system can be generated based on the pedal's opening degree and the timing of pedal depressing. This loading command includes the target loading current value that the fuel cell stack needs to achieve and the air compressor's acceleration timing. It is important to note that to ensure loading efficiency, the air compressor's acceleration timing is approximately the same as the driver's accelerator pedal depressing.

[0044] Next, at the same moment the loading command is received, the current current of the fuel cell stack in the hydrogen fuel cell system is obtained, i.e., the real-time fuel cell stack current value of the hydrogen fuel cell system is obtained. Then, based on the real-time fuel cell stack current value and the target loading fuel cell stack current value, the pre-constructed current-speed mapping table is consulted to obtain the real-time air compressor speed and the target air compressor speed of the hydrogen fuel cell system.

[0045] The above steps, based on a lookup mechanism using a mapping table, ensure a precise correspondence between the air compressor speed data and the stack current requirements. Therefore, in subsequent loading control calculations, such as determining the current loading duration and the air compressor speed loading duration, more accurate and reliable input parameters can be obtained. This significantly improves the matching accuracy between oxygen supply and stack oxygen consumption rate during loading, effectively avoiding problems such as cathode starvation, output voltage drop, and system performance degradation caused by insufficient oxygen. This ensures the stability and reliability of the hydrogen fuel cell system during rapid loading and helps extend its service life.

[0046] In this embodiment, step 102 includes: Step 1021: Extract the loading power and air compressor acceleration time of the hydrogen fuel cell system from the loading command.

[0047] Step 1022: Query the preset current loading rate library according to the loaded power to obtain the current loading rate of the hydrogen fuel cell system; wherein, the current loading rate library includes the lowest current rate, the medium current rate and the highest current rate.

[0048] In this embodiment, after extracting the loading power of the hydrogen fuel cell system and the air compressor acceleration time from the loading command, different current loading rates are required based on different loading power levels. For example, when the driver needs to overtake or climb hills, requiring high power, the maximum current loading rate of the current vehicle is used; when the driver needs to accelerate slightly, the power demand on the fuel cell system is not as high, and a smaller current loading rate is used. Therefore, this embodiment can pre-set different current loading rates to adapt to different acceleration conditions. For example, a minimum current rate can be set. Medium current rate and maximum current rate .

[0049] The above steps dynamically select a current loading rate that matches the current loading requirement by querying a preset current loading rate library based on the loaded power, rather than using a single fixed rate. The current loading rate library provides multiple options, including minimum, medium, and maximum current rates, allowing the system to flexibly select the most suitable loading speed according to the loaded power. This adaptive current loading rate matching mechanism effectively solves the problem of mismatch between the stack current loading rate and the air compressor speed change rate under traditional fixed-rate control. It ensures that the stack receives sufficient oxygen supply under different loading requirements, thereby maintaining a stable electrochemical reaction and avoiding performance degradation phenomena such as output voltage drop and increased fluctuations due to insufficient oxygen supply. It also effectively prevents localized overheating and membrane electrode damage caused by cathode starvation, thus improving the overall performance and service life of the hydrogen fuel cell system.

[0050] In this embodiment, step 103 includes: Step 1031: Obtain the current difference between the target loaded stack current value and the real-time stack current value, and use the current difference as the current loading amplitude of the hydrogen fuel cell system.

[0051] Step 1032: Obtain the speed difference between the target air compressor speed and the real-time air compressor speed, and use the speed difference as the speed loading amplitude of the hydrogen fuel cell system.

[0052] Step 1033: Obtain the ratio of the speed loading amplitude to the preset air compressor speed increase rate, and use the speed ratio as the air compressor speed loading duration of the hydrogen fuel cell system.

[0053] Step 1034: When the current loading rate is the minimum current rate, obtain a first ratio of the current loading amplitude to the minimum current rate, and use the first ratio as the current loading duration of the hydrogen fuel cell system.

[0054] Step 1035: When the current loading rate is the medium current rate, obtain a second ratio of the current loading amplitude to the medium current rate, and use the second ratio as the current loading duration of the hydrogen fuel cell system.

[0055] Step 1036: When the current loading rate is the highest current rate, obtain the third ratio of the current loading amplitude to the highest current rate, and use the third ratio as the current loading duration of the hydrogen fuel cell system.

[0056] In this embodiment, it is assumed that the hydrogen fuel cell system operates at the minimum loading rate. When applying current, the target stack current value of the hydrogen fuel cell system is determined. Then, it will be compared with the real-time fuel cell stack current value before loading. By comparison, the current loading amplitude is obtained. = - Given that the current loading rate is... The duration of current loading can be calculated. = / .

[0057] Assuming the hydrogen fuel cell system operates at a moderate loading rate When applying current, the target stack current value of the hydrogen fuel cell system is determined. Then, it will be compared with the real-time fuel cell stack current value before loading. By comparison, the current loading amplitude is obtained. = - Given that the current loading rate is... The duration of current loading can be calculated. = / .

[0058] And assuming the hydrogen fuel cell system operates at its highest loading rate When applying current, the target stack current value of the hydrogen fuel cell system is determined. Then, it will be compared with the real-time fuel cell stack current value before loading. By comparison, the current loading amplitude is obtained. = - Given that the current loading rate is... The duration of current loading can be calculated. = / .

[0059] When determining the air compressor speed and loading duration, it is assumed that the real-time fuel cell current value... The corresponding real-time air compressor speed is The target loaded stack current value is The corresponding target air compressor speed is Since the rate of increase of air compressor speed is a fixed value n for different vehicles, the air compressor speed can be calculated from the real-time air compressor speed. Increase to the target air compressor speed Required air compressor speed and loading time = ( - ) / n.

[0060] The above steps accurately obtain the current difference between the target loaded stack current value and the real-time stack current value as the current loading amplitude, and obtain the speed difference between the target air compressor speed and the real-time air compressor speed as the speed loading amplitude. This application provides an accurate quantitative basis for subsequent duration calculation. Based on this, the speed loading amplitude is compared with the preset air compressor speed increase rate to dynamically determine the air compressor speed loading duration, avoiding the limitations of a fixed advance time strategy. Furthermore, this application calculates the ratio of the current loading amplitude to the corresponding rate according to different current loading rates (including minimum, medium, and maximum current rates) to obtain an accurate current loading duration. This mechanism of adaptively adjusting the current loading duration according to the actual loading rate ensures that the stack current loading rate matches the air compressor's gas supply capacity under various loading requirements. Therefore, the duration calculation method proposed in this application can significantly improve the oxygen supply accuracy of the hydrogen fuel cell system during dynamic loading, effectively prevent the occurrence of "cathode starvation" in the stack, thereby ensuring stable stack operation, extending its service life, and improving the overall system performance.

[0061] In this embodiment, step 104 includes: Step 1041: When the current loading rate is the minimum current rate, obtain the first difference between the air compressor speed loading time and the first ratio, and use the first difference as the first air compressor advance start time of the hydrogen fuel cell system; add the air compressor acceleration time to the first air compressor advance start time to obtain the stack current loading time of the hydrogen fuel cell system.

[0062] Step 1042: When the current loading rate is a medium current rate, obtain the first sum of the first air compressor early start time and the second ratio; obtain the second difference between the air compressor speed loading time and the first sum, and use the second difference as the second air compressor early start time of the hydrogen fuel cell system; add the air compressor acceleration time to the second air compressor early start time to obtain the stack current loading time of the hydrogen fuel cell system.

[0063] Step 1043: When the current loading rate is the highest current rate, obtain the second sum of the early start-up time of the second air compressor, the early start-up time of the first air compressor, and the second ratio; obtain the third difference between the air compressor speed loading time and the second sum, and use the third difference as the early start-up time of the third air compressor of the hydrogen fuel cell system; add the air compressor acceleration time to the early start-up time of the third air compressor to obtain the stack current loading time of the hydrogen fuel cell system.

[0064] In this embodiment, when controlling the air compressor to accelerate in advance based on the calculated advance start-up time, different advance start-up times need to be determined according to different current loading rates. Specifically, when the hydrogen fuel cell system is loading current at the lowest current rate, the air compressor is controlled to advance the start-up time of the first air compressor. When acceleration begins prematurely, the airflow required for the electrochemical reaction during the loading process is precisely met. Therefore, during this process, the... = - .

[0065] When the hydrogen fuel cell system is charged with current at a moderate current rate, at this time + < That is, the air compressor is ahead of schedule Acceleration is no longer sufficient to meet the air flow requirements of the electrochemical reactions during the loading process. In this case, controlling the air compressor advance time to... + Further increasing the advance acceleration time of the air compressor can avoid the problem of insufficient airflow to meet the load requirements. = -( + ).

[0066] When the hydrogen fuel cell system is loaded with current at its highest current rate, at this time... + + < That is, the air compressor is ahead of schedule + Acceleration is no longer sufficient to meet the air flow requirements of the electrochemical reactions during the loading process. In this case, controlling the air compressor advance time to... + + Further increasing the advance acceleration time of the air compressor can avoid the problem of insufficient airflow to meet the load requirements. = -( + + ).

[0067] The above steps, through precise timing control, avoid problems such as excessive oxygen and energy waste due to premature compressor start-up at different current rates, or insufficient oxygen supply and cathode starvation due to delayed start-up. Overall, this solution effectively improves the performance stability, response efficiency, and lifespan of the hydrogen fuel cell system under low-speed loading conditions, ensuring coordinated operation of the system at different loading rates.

[0068] In this embodiment, step 105 includes: Step 1051: Control the air compressor of the hydrogen fuel cell system to increase its speed according to the air compressor acceleration time and the preset air compressor speed increase rate, and obtain the air compressor speed in real time.

[0069] Step 1052: Control the current loading of the hydrogen fuel cell system stack according to the current loading time and the current loading rate, and acquire the current of the stack in real time.

[0070] Step 1053: When the rotational speed reaches the target air compressor speed and the current reaches the target loading stack current value, the loading control of the hydrogen fuel cell system is completed.

[0071] In this embodiment, when the fuel cell controller receives the command to load the target current, it controls the air compressor to start operating and accelerates from the initial speed at a fixed rate of increase in air compressor speed. Secondly, based on the current loading rate determined by the fuel cell controller based on the algorithm, the time interval between the moment the air compressor loads and the moment the hydrogen fuel cell stack begins to load the current can be obtained. Finally, the loading begins after a predetermined time interval according to the obtained time interval.

[0072] In this embodiment one implementation, as Figure 3 As shown, when the hydrogen fuel cell system is loaded with current 1, the air compressor is activated in advance. The acceleration precisely meets the airflow requirements during the loading process; keep the air compressor in advance. With the acceleration unchanged, the air flow requirements during the loading process cannot be met when the current is 2. Therefore, it is necessary to further increase the air compressor's loading time to [a later date]. + This is necessary to meet the airflow requirements under the current load rate; similarly, the air compressor should be preloaded in advance. + The current remains unchanged. Even when the load is applied at current 3, the airflow requirement at the current load rate cannot be met, necessitating a further increase in the air compressor's advance load application time. + + That's acceptable.

[0073] The above steps continuously monitor the real-time air compressor speed and fuel cell stack current, using a dual-condition judgment (i.e., the air compressor speed reaches the target air compressor speed and the fuel cell stack current reaches the target loading current value) as the completion mark for loading control. This ensures that the air compressor can always provide a sufficient oxygen supply throughout the loading process, precisely matching the oxygen consumption rate of the fuel cell stack, thus significantly reducing the risk of insufficient oxygen supply. Therefore, it can effectively suppress the decrease in the average output voltage and the increase in fluctuation, improve the system's output performance, shorten the recovery time, and fundamentally avoid local overheating and membrane electrode damage caused by "cathode starvation," thereby extending the service life of the hydrogen fuel cell system and improving the system's reliability and stability.

[0074] On the other hand, refer to Figure 2 This embodiment also discloses a loading control system for a hydrogen fuel cell system, including an instruction loading module 201, a data matching module 202, a duration calculation module 203, a time determination module 204, and a loading control module 205.

[0075] The instruction loading module 201 is used to receive the loading instruction of the hydrogen fuel cell system, and to obtain the real-time stack current value, the target loading stack current value, the real-time air compressor speed and the target air compressor speed of the hydrogen fuel cell system according to the loading instruction.

[0076] The data matching module 202 is used to match the current loading rate and air compressor acceleration time of the hydrogen fuel cell system according to the loading command.

[0077] The duration calculation module 203 is used to obtain the current loading duration of the hydrogen fuel cell system based on the real-time stack current value, the target loading stack current value and the current loading rate, and to determine the air compressor speed loading duration of the hydrogen fuel cell system based on the real-time air compressor speed and the target air compressor speed.

[0078] The timing determination module 204 is used to determine the stack current loading time of the hydrogen fuel cell system based on the air compressor speed loading time, the current loading time, and the air compressor acceleration time.

[0079] The loading control module 205 is used to implement the loading control of the hydrogen fuel cell system based on the air compressor acceleration time, the stack current loading time, the target loading stack current value, and the target air compressor speed.

[0080] In this embodiment, the instruction loading module 201 includes a current unit and a speed unit.

[0081] The current unit is used to obtain the real-time stack current value and the target loading stack current value of the hydrogen fuel cell system according to the loading command of the hydrogen fuel cell system.

[0082] The speed unit is used to query a pre-built current-speed mapping table based on the real-time stack current value to obtain the real-time air compressor speed of the hydrogen fuel cell system; and to query the current-speed mapping table based on the target loaded stack current value to obtain the target air compressor speed of the hydrogen fuel cell system.

[0083] This embodiment provides a loading control method and system for a hydrogen fuel cell system. Based on different loading rates of the hydrogen fuel cell system, different advance times of the air compressor are controlled to ensure sufficient airflow during loading. This mitigates the problem of excessively low average voltage and excessive variance in the fuel cell stack caused by a decrease in oxygen concentration at the electrochemical reaction interface, thereby improving the output performance of the hydrogen fuel cell system and reducing the time required for the output power to stabilize. By controlling the air compressor speed with different advance times according to different fuel cell stack current loading rates and amplitudes, excessively low oxygen concentration at the reaction interface is avoided, thus preventing damage to the membrane electrode assembly due to localized hot spots and extending the service life of the hydrogen fuel cell system.

[0084] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the scope of protection of the present invention. In particular, it should be noted that any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention for those skilled in the art.

Claims

1. A loading control method for a hydrogen fuel cell system, characterized in that, include: Receive loading instructions from the hydrogen fuel cell system, and obtain the real-time stack current value, target loading stack current value, real-time air compressor speed, and target air compressor speed of the hydrogen fuel cell system according to the loading instructions; The current loading rate and air compressor acceleration time of the hydrogen fuel cell system are matched according to the loading command; The current loading duration of the hydrogen fuel cell system is obtained based on the real-time stack current value, the target loaded stack current value, and the current loading rate; and the air compressor speed loading duration of the hydrogen fuel cell system is determined based on the real-time air compressor speed and the target air compressor speed. The stack current loading time of the hydrogen fuel cell system is determined based on the air compressor speed loading time, the current loading time, and the air compressor acceleration time. The loading control of the hydrogen fuel cell system is achieved based on the air compressor acceleration time, the stack current loading time, the target loaded stack current value, and the target air compressor speed.

2. The loading control method for a hydrogen fuel cell system according to claim 1, characterized in that, The step of receiving the loading command of the hydrogen fuel cell system and obtaining the real-time stack current value, target loading stack current value, real-time air compressor speed, and target air compressor speed of the hydrogen fuel cell system according to the loading command includes: The real-time stack current value and the target loading stack current value of the hydrogen fuel cell system are obtained according to the loading command of the hydrogen fuel cell system. The real-time air compressor speed of the hydrogen fuel cell system is obtained by querying a pre-built current-speed mapping table based on the real-time stack current value. The target air compressor speed of the hydrogen fuel cell system is obtained by querying the current-speed mapping table based on the target loaded stack current value.

3. The loading control method for a hydrogen fuel cell system according to claim 1, characterized in that, The step of matching the current loading rate and air compressor acceleration time of the hydrogen fuel cell system according to the loading command includes: Extract the loading power and air compressor acceleration time of the hydrogen fuel cell system from the loading command; The current loading rate of the hydrogen fuel cell system is obtained by querying a preset current loading rate library based on the loaded power; wherein, the current loading rate library includes the lowest current rate, the medium current rate, and the highest current rate.

4. The loading control method for a hydrogen fuel cell system according to claim 3, characterized in that, The step of obtaining the current loading duration of the hydrogen fuel cell system based on the real-time stack current value, the target loaded stack current value, and the current loading rate, and determining the air compressor speed loading duration of the hydrogen fuel cell system based on the real-time air compressor speed and the target air compressor speed, includes: The current difference between the target loaded stack current value and the real-time stack current value is obtained, and the current difference is used as the current loading amplitude of the hydrogen fuel cell system. The speed difference between the target air compressor speed and the real-time air compressor speed is obtained, and the speed difference is used as the speed loading amplitude of the hydrogen fuel cell system. The ratio of the speed loading amplitude to the preset air compressor speed increase rate is obtained, and the speed ratio is used as the air compressor speed loading duration of the hydrogen fuel cell system. When the current loading rate is the minimum current rate, a first ratio of the current loading amplitude to the minimum current rate is obtained, and the first ratio is used as the current loading duration of the hydrogen fuel cell system. When the current loading rate is the medium current rate, a second ratio of the current loading amplitude to the medium current rate is obtained, and the second ratio is used as the current loading duration of the hydrogen fuel cell system. When the current loading rate is the highest current rate, a third ratio of the current loading amplitude to the highest current rate is obtained, and the third ratio is used as the current loading duration of the hydrogen fuel cell system.

5. The loading control method for a hydrogen fuel cell system according to claim 4, characterized in that, The step of determining the stack current loading time of the hydrogen fuel cell system based on the air compressor speed loading time, the current loading time, and the air compressor acceleration time includes: When the current loading rate is the minimum current rate, the first difference between the air compressor speed loading time and the first ratio is obtained, and the first difference is used as the first air compressor early start time of the hydrogen fuel cell system. The acceleration time of the air compressor is added to the advance start time of the first air compressor to obtain the stack current loading time of the hydrogen fuel cell system.

6. A loading control method for a hydrogen fuel cell system according to any one of claims 4-5, characterized in that, The step of determining the stack current loading time of the hydrogen fuel cell system based on the air compressor speed loading time, the current loading time, and the air compressor acceleration time includes: When the current loading rate is a medium current rate, obtain the first sum of the first air compressor early start time and the second ratio; Obtain the second difference between the air compressor speed loading time and the first sum, and use the second difference as the advance start time of the second air compressor of the hydrogen fuel cell system; The acceleration time of the air compressor is added to the advance start time of the second air compressor to obtain the stack current loading time of the hydrogen fuel cell system.

7. The loading control method for a hydrogen fuel cell system according to claim 6, characterized in that, The step of determining the stack current loading time of the hydrogen fuel cell system based on the air compressor speed loading time, the current loading time, and the air compressor acceleration time includes: When the current loading rate is the highest current rate, obtain the second sum of the early start time of the second air compressor, the early start time of the first air compressor, and the second ratio; Obtain the third difference between the air compressor speed loading time and the second sum, and use the third difference as the advance start time of the third air compressor of the hydrogen fuel cell system; The acceleration time of the air compressor is added to the advance start time of the third air compressor to obtain the stack current loading time of the hydrogen fuel cell system.

8. The loading control method for a hydrogen fuel cell system according to claim 7, characterized in that, The loading control of the hydrogen fuel cell system based on the air compressor acceleration time, the fuel cell stack current loading time, the target loaded fuel cell stack current value, and the target air compressor speed includes: The air compressor of the hydrogen fuel cell system is controlled to accelerate according to the air compressor acceleration time and the preset air compressor speed increase rate, and the air compressor speed is acquired in real time. The current loading of the hydrogen fuel cell system is controlled according to the current loading time and the current loading rate, and the current of the fuel cell is acquired in real time. When the rotational speed reaches the target air compressor speed and the current reaches the target loading stack current value, the loading control of the hydrogen fuel cell system is completed.

9. A loading control system for a hydrogen fuel cell system, characterized in that, It includes an instruction loading module, a data matching module, a duration calculation module, a time determination module, and a loading control module; The instruction loading module is used to receive the loading instruction of the hydrogen fuel cell system, and to obtain the real-time stack current value, the target loading stack current value, the real-time air compressor speed and the target air compressor speed of the hydrogen fuel cell system according to the loading instruction. The data matching module is used to match the current loading rate and air compressor acceleration time of the hydrogen fuel cell system according to the loading command. The duration calculation module is used to obtain the current loading duration of the hydrogen fuel cell system based on the real-time stack current value, the target loaded stack current value and the current loading rate, and to determine the air compressor speed loading duration of the hydrogen fuel cell system based on the real-time air compressor speed and the target air compressor speed. The timing determination module is used to determine the stack current loading time of the hydrogen fuel cell system based on the air compressor speed loading time, the current loading time, and the air compressor acceleration time. The loading control module is used to control the loading of the hydrogen fuel cell system based on the air compressor acceleration time, the stack current loading time, the target stack current value, and the target air compressor speed.

10. A loading control system for a hydrogen fuel cell system according to claim 9, characterized in that, The instruction loading module includes a current unit and a speed unit; The current unit is used to obtain the real-time stack current value and the target loading stack current value of the hydrogen fuel cell system according to the loading command of the hydrogen fuel cell system. The speed unit is used to query a pre-built current-speed mapping table based on the real-time stack current value to obtain the real-time air compressor speed of the hydrogen fuel cell system; and to query the current-speed mapping table based on the target loaded stack current value to obtain the target air compressor speed of the hydrogen fuel cell system.

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