Method for controlling hydrogen pressure of fuel cell and control system thereof

Abstract

The application discloses a kind of control method and control system of fuel cell hydrogen pressure.It is controlled method includes: hydrogen release working condition is divided into hydrogen release sufficient and hydrogen release insufficient, and hydrogen pressure into stack is divided into overpressure dangerous area, overpressure area, working area, low pressure area and low pressure dangerous area;The linkage relationship of hydrogen release working condition and hydrogen pressure into stack is established, wherein, linkage relationship adapts hydrogen release output characteristic and power demand of electric pile;Real-time acquisition hydrogen release working condition and hydrogen pressure into stack, and based on linkage relationship, hydrogen supply valve opening and electric pile output power are cooperatively regulated.The technical scheme of the application can effectively alleviate the situation of hydrogen supply insufficient, improve electric pile operating efficiency and service life.

Description

Technical Field

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

[0002] Fuel cell stacks, as devices that directly convert chemical energy into electrical energy, can be applied in fields such as vehicle-mounted power supplies, portable power sources, and distributed power generation. However, in existing hydrogen pressure control technologies, the hydrogen release system and the control process of the hydrogen pressure at the stack are independent. These technologies often adjust the hydrogen supply parameters of the hydrogen release module or the pressure threshold at the stack entrance separately, ignoring the direct impact of actual changes in hydrogen release capacity on the hydrogen pressure at the stack entrance. Furthermore, existing hydrogen pressure regulation methods lack coordination, relying heavily on single components for pressure correction, which is insufficient to alleviate hydrogen supply shortages and affects the stack's operating efficiency and lifespan. Summary of the Invention

[0003] To address the shortcomings of existing technologies, this invention provides a method for controlling hydrogen pressure in fuel cells, which can effectively alleviate insufficient hydrogen supply and improve the operating efficiency and service life of the fuel cell stack.

[0004] This application provides a fuel cell hydrogen pressure control method, the control method comprising:

[0005] The hydrogen release working state is divided into sufficient hydrogen release and insufficient hydrogen release, and the hydrogen pressure at the reactor core is divided into overpressure danger zone, overpressure zone, working zone, low pressure zone and low pressure danger zone.

[0006] Establish a linkage relationship between the hydrogen release operating state and the hydrogen pressure fed into the stack, wherein the linkage relationship is adapted to the hydrogen release output characteristics and the power requirements of the fuel cell stack;

[0007] The hydrogen release status and the hydrogen pressure fed into the stack are collected in real time, and the opening degree of the hydrogen supply valve and the output power of the stack are coordinated and controlled based on the aforementioned linkage.

[0008] In one aspect, the step of establishing the linkage between the hydrogen release operating state and the reactor hydrogen pressure includes:

[0009] A linkage relationship is constructed based on a preset association table, wherein the association table records the corresponding stack power control strategies for different hydrogen release operating states and different infeed hydrogen pressures.

[0010] In one aspect, the stack power regulation strategy includes power boosting, power maintenance, and power reduction;

[0011] When hydrogen release is sufficient and the infeed hydrogen pressure is within the operating range, power maintenance or power boost is performed.

[0012] When hydrogen release is insufficient and the hydrogen pressure at the reactor core is in a low-pressure or low-pressure danger zone, the operating power is reduced.

[0013] When the infeed hydrogen pressure is in the overpressure zone or overpressure danger zone, the execution power is reduced.

[0014] In one aspect, the control method further includes:

[0015] Based on the pre-set trend fitting model, the hydrogen pressure change trend is analyzed, and the zone of the infeed hydrogen pressure in the future within a pre-set time period is predicted.

[0016] If the system enters an overpressure or low-pressure danger zone, power pre-regulation measures should be initiated in advance.

[0017] In one aspect, the steps of dividing the reactor feed hydrogen pressure into overpressure hazard zone, overpressure zone, operating zone, low-pressure zone, and low-pressure hazard zone include:

[0018] Set overpressure hazard threshold, overpressure threshold, underpressure threshold, and underpressure hazard threshold;

[0019] A region where the hydrogen pressure at the reactor core exceeds the overpressure hazard threshold is defined as an overpressure hazard zone.

[0020] The overpressure zone is defined as the hydrogen infeed pressure between the overpressure threshold and the overpressure danger threshold.

[0021] The working zone is defined as the hydrogen infeed pressure between the low pressure threshold and the overpressure threshold.

[0022] A low-pressure zone is defined as a reactor hydrogen pressure between the low-pressure danger threshold and the low-pressure threshold.

[0023] A low-pressure hazard zone is defined as a hydrogen pressure below the low-pressure hazard threshold.

[0024] In one aspect, the steps of setting overpressure hazard threshold, overpressure threshold, underpressure threshold, and underpressure hazard threshold include:

[0025] Set a first, second, third, and fourth initial value that decreases sequentially;

[0026] Based on the influence of fuel cell stack aging degree, ambient temperature and humidity, and altitude and air pressure on fuel cell stack operation, the first initial value, the second initial value, the third initial value, and the fourth initial value are updated and corrected.

[0027] An overpressure danger threshold is formed based on the first initial value, an overpressure threshold is formed based on the second initial value, a low pressure threshold is formed based on the third initial value, and a low pressure danger threshold is formed based on the fourth initial value.

[0028] In one aspect, the control method further includes:

[0029] Real-time acquisition of the first hydrogen pressure data at the hydrogen release source and the second hydrogen pressure data at the reactor inlet;

[0030] Calculate the pressure difference between the first hydrogen pressure data and the second hydrogen pressure data;

[0031] If the pressure difference exceeds the preset range, the adjustment range of the hydrogen supply valve opening will be adjusted.

[0032] In one aspect, the steps of coordinating the opening degree of the hydrogen supply valve and the output power of the fuel cell stack based on the aforementioned linkage include:

[0033] The hydrogen supply valve opening is controlled based on pulse width modulation signals, with an adjustment accuracy of ±1% of the maximum valve opening, and the response period of the stack output power regulation is consistent with the hydrogen pressure acquisition period.

[0034] In one aspect, the control method further includes:

[0035] Identify the current operating stage of the fuel cell stack, which includes the open circuit stage, the activation polarization stage, and the normal operation stage;

[0036] Specifically, during the open-circuit phase, the hydrogen supply valve is maintained at its minimum opening and output power; during the activation and polarization phase, the opening of the hydrogen supply valve and the output power of the fuel cell stack are gradually increased; and during the normal operation phase, the opening of the hydrogen supply valve and the output power of the fuel cell stack are coordinated and regulated according to the aforementioned linkage relationship.

[0037] Furthermore, to address the aforementioned problems, this application also provides a control system for hydrogen pressure in a fuel cell, the control system comprising:

[0038] The partitioning module is used to divide the hydrogen release working state into sufficient hydrogen release and insufficient hydrogen release, and to divide the infeed hydrogen pressure into overpressure danger zone, overpressure zone, working zone, low pressure zone and low pressure danger zone.

[0039] A construction module is used to establish the linkage between the hydrogen release working state and the hydrogen pressure fed into the stack, wherein the linkage is adapted to the hydrogen release output characteristics and the power requirements of the fuel cell stack.

[0040] The control module is used to collect the hydrogen release status and the hydrogen pressure fed into the stack in real time, and to coordinate the opening of the hydrogen supply valve and the output power of the stack based on the aforementioned linkage.

[0041] The beneficial effects of this invention are as follows: by dividing the hydrogen release working state into sufficient and insufficient hydrogen release, and further subdividing the infeed hydrogen pressure into five zones, the hydrogen release capacity and infeed pressure state can be precisely identified, making their matching relationship quantifiable and controllable; by establishing a linkage relationship between the hydrogen release output characteristics and the stack power demand, the independent situation between the hydrogen release system and the infeed hydrogen pressure control is reduced, and the isolation of the regulation and control process is reduced; and based on this linkage relationship, the status is collected in real time and the opening of the hydrogen supply valve and the stack output power are coordinated and adjusted, realizing bidirectional adaptation between hydrogen supply regulation and power demand, that is, when hydrogen release is sufficient, the power output is matched on demand, and when hydrogen release is insufficient, the hydrogen supply gap can be avoided from widening through coordinated regulation. The pressure state can be quickly corrected through bidirectional regulation, thereby reducing the problems of independence and insufficient regulation coordination in the control process, alleviating insufficient hydrogen supply, reducing the risk of pressure fluctuation failure, and improving the stack operating efficiency and service life. Attached Figure Description

[0042] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the accompanying drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn to scale.

[0043] Figure 1 This is a schematic diagram of the process steps for controlling hydrogen pressure in the fuel cell according to this application;

[0044] Figure 2 This is a schematic diagram of the process steps for proactively regulating power in the control method of this application;

[0045] Figure 3 This is a schematic diagram of the process steps for classifying the hydrogen pressure fed into the reactor in the control method of this application;

[0046] Figure 4 This is a schematic diagram of the process steps for setting the partition threshold in the control method of this application;

[0047] Figure 5 This is a schematic diagram of the process steps for regulating the hydrogen release source and the reactor inlet in the control method of this application;

[0048] Figure 6 This is a schematic diagram of the functional modules of the fuel cell hydrogen pressure control system of this application. Detailed Implementation

[0049] The embodiments of the technical solution of the present invention will now be described in detail with reference to the accompanying drawings. These embodiments are merely illustrative of the technical solution of the present invention and are therefore intended to limit the scope of protection of the present invention.

[0050] It should be noted that, unless otherwise stated, the technical or scientific terms used in this application should have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains.

[0051] This application provides a method for controlling hydrogen pressure in a fuel cell. The working principle of the fuel cell stack is to directly convert the chemical energy of hydrogen and oxygen into electrical energy through an electrochemical oxidation-reduction reaction. The process does not involve combustion or mechanical movement, resulting in high energy conversion efficiency and clean emissions.

[0052] A typical fuel cell stack consists of multiple individual cells connected in series. Each cell contains an anode, a cathode, and an electrolyte membrane. When hydrogen gas is introduced to the anode, it decomposes into protons (H⁺) and electrons (e⁻) under the action of a catalyst. Electrons form an electric current through an external circuit, while protons migrate through the electrolyte membrane to the cathode. Simultaneously, oxygen (or air) is introduced to the cathode, where it combines with electrons and protons on the surface of the cathode catalyst to form water. This continuous reaction ensures a stable output of electrical energy. Throughout the process, the electrolyte membrane allows only protons to pass through, preventing gas leakage and electron passage, thus ensuring the orderly conduct of the reaction.

[0053] like Figure 1 As shown, the control method of this application includes:

[0054] Step S10 involves classifying the hydrogen release operating status into sufficient and insufficient hydrogen release, and the infeed hydrogen pressure into overpressure danger zone, overpressure zone, operating zone, low pressure zone, and low pressure danger zone. Data is collected using hydrogen release pressure and flow sensors to classify the hydrogen release operating status into two categories: sufficient and insufficient hydrogen release, reflecting the actual supply capacity of the hydrogen source. Simultaneously, referencing the safe operating pressure range and working pressure interval of the fuel cell stack, the infeed hydrogen pressure is further divided into five levels: overpressure danger zone, overpressure zone, operating zone, low pressure zone, and low pressure danger zone, achieving refined differentiation of the infeed hydrogen pressure status. The hydrogen release operating status refers to the hydrogen supply capacity status of the fuel cell hydrogen source system, divided into sufficient and insufficient hydrogen release, determined by data collected from hydrogen source pressure and flow sensors, directly reflecting whether the hydrogen supply matches the stack power requirements. The infeed hydrogen pressure is the real-time pressure value when hydrogen enters the fuel cell stack, a core parameter affecting stack reaction efficiency and operational safety, and must be controlled within a suitable pressure range to avoid overpressure risks or insufficient hydrogen supply.

[0055] Step S20 establishes a linkage between the hydrogen release operating state and the inlet hydrogen pressure, whereby the linkage adapts to the hydrogen release output characteristics and the stack power requirements. The linkage refers to the adaptive control logic between the hydrogen release operating state and the inlet hydrogen pressure, adapting to the hydrogen release output characteristics (pressure, flow rate) and the stack power requirements, clarifying the coordinated control direction of the hydrogen supply valve opening and the stack output power under different operating conditions. Based on the operating characteristics of the fuel cell stack, fully considering the hydrogen release output characteristics such as output pressure and flow rate, as well as the power demand patterns of the stack under different operating conditions, a linkage between the hydrogen release operating state and the inlet hydrogen pressure is established through data fitting and operating condition verification. This linkage clarifies the control direction corresponding to different hydrogen release states and different inlet hydrogen pressure zones, ensuring that subsequent control actions can both match the hydrogen release supply capacity and meet the stack power output requirements, avoiding supply-demand imbalances caused by single control.

[0056] Step S30: Real-time acquisition of hydrogen release status and infeed hydrogen pressure, and coordinated control of hydrogen supply valve opening and stack output power based on linkage. Using hydrogen release pressure or flow sensors and infeed hydrogen pressure sensors, the system continuously acquires hydrogen release status data and infeed hydrogen pressure data to monitor the entire hydrogen pressure chain in real time. Based on linkage, the system synchronously controls hydrogen supply valve opening and stack output power. When the infeed hydrogen pressure is in the overpressure zone, the overpressure is alleviated by reducing the hydrogen supply valve opening and decreasing stack output power. When the infeed hydrogen pressure is in the low-pressure zone and hydrogen release is insufficient, the hydrogen supply valve opening is adjusted and stack output power is reduced to prevent hydrogen starvation. When hydrogen release is sufficient and the infeed hydrogen pressure is within the operating range, the hydrogen supply valve opening and power are maintained or moderately adjusted to ensure the stack operates within the high-efficiency and safe range, thereby achieving a dynamic balance between hydrogen pressure and output power.

[0057] In this embodiment, by dividing the hydrogen release operation into sufficient and insufficient hydrogen release states, and further subdividing the infeed hydrogen pressure into five zones, the hydrogen release capacity and infeed pressure state are precisely identified, making their matching relationship quantifiable and controllable. Furthermore, by establishing a linkage relationship between the hydrogen release output characteristics and the stack power demand, the independence of the hydrogen release system and the infeed hydrogen pressure control is reduced, minimizing the isolation of the regulation and control process. Based on this linkage relationship, the status is collected in real time, and the opening of the hydrogen supply valve and the stack output power are coordinated and adjusted. This achieves bidirectional adaptation between hydrogen supply regulation and power demand; that is, when hydrogen release is sufficient, power output is matched to demand; when hydrogen release is insufficient, coordinated regulation can prevent the hydrogen supply gap from widening. The pressure state is quickly corrected through bidirectional regulation, thereby reducing the problems of independence and insufficient coordination in the control process, alleviating insufficient hydrogen supply, reducing the risk of pressure fluctuation failures, and improving the stack operating efficiency and service life.

[0058] In one embodiment of this application, the step of establishing the linkage between the hydrogen release operating state and the reactor hydrogen pressure includes:

[0059] Step S210 involves constructing a linkage relationship based on a pre-defined association table. This table records the corresponding stack power control strategies for different hydrogen release operating states and different infeed hydrogen pressures. The association table is pre-formed through the analysis and verification of full-condition experimental data from the stack. For example, the horizontal dimension of the table includes two types of hydrogen release operating states: sufficient hydrogen release and insufficient hydrogen release. The vertical dimension includes five zones for infeed hydrogen pressure: overpressure danger zone, overpressure zone, operating zone, low-pressure zone, and low-pressure danger zone. Each cell in the table explicitly records the stack power control strategy for the corresponding operating condition. For instance, when hydrogen release is sufficient and the infeed hydrogen pressure is in the operating zone, the strategy is to maintain the current power or moderately increase the power. When hydrogen release is insufficient and the infeed hydrogen pressure is in the low-pressure zone, the power is rapidly reduced to minimize hydrogen consumption. When the infeed hydrogen pressure is in the overpressure zone, regardless of the hydrogen release state, the power is preferentially reduced to alleviate hydrogen pressure pressure. Through the association table, the abstract linkage relationship is directly transformed into explicit power control commands.

[0060] In one embodiment of this application, the power regulation strategy of the fuel cell stack includes power boosting, power maintenance, and power reduction; different regulation strategies correspond to the hydrogen pressure and output power adaptation requirements under different operating conditions, ensuring that the fuel cell stack can operate efficiently within a safe range and avoiding failures caused by power and hydrogen pressure mismatch.

[0061] Specifically, when hydrogen release is sufficient and the infeed hydrogen pressure is within the operating range, power maintenance or power boosting strategies are implemented. When the hydrogen release module monitoring shows sufficient hydrogen release, such as when the hydrogen release pressure and flow rate meet the current and potential power requirements of the fuel cell stack, and the infeed hydrogen pressure is within the operating range (i.e., within the preset high-efficiency and safe range, with no risk of overpressure or underpressure), power maintenance or power boosting strategies can be implemented. If the current power of the fuel cell stack already matches the load demand, maintaining the existing power can ensure operational stability. If the load demand increases or the system needs to optimize energy efficiency, the power can be moderately increased. In this case, sufficient hydrogen release can meet the hydrogen consumption demand after the power increase, and the infeed hydrogen pressure can also be stabilized within the operating range, avoiding insufficient hydrogen supply or pressure fluctuations.

[0062] When hydrogen release is insufficient and the infeed hydrogen pressure is in the low-pressure or low-pressure danger zone, the power reduction strategy is implemented. When insufficient hydrogen release from the hydrogen release module is detected, and the release pressure and flow rate cannot meet the current hydrogen consumption requirements of the fuel cell stack, and the infeed hydrogen pressure has dropped to the low-pressure or low-pressure danger zone, posing a risk of hydrogen starvation, the power reduction strategy is immediately implemented. By reducing the fuel cell stack output power, the rate of hydrogen consumption by the stack is reduced, alleviating the imbalance between hydrogen supply and consumption, preventing further drops in infeed hydrogen pressure leading to hydrogen starvation, and thus preventing irreversible damage such as single-cell reverse polarity and catalyst corrosion caused by insufficient hydrogen, buying time for hydrogen pressure recovery.

[0063] When the infeed hydrogen pressure is in the overpressure zone or overpressure danger zone, power reduction is implemented. Regardless of whether the hydrogen release module is currently in a state of sufficient or insufficient hydrogen release, as long as the infeed hydrogen pressure monitoring shows that it is in the overpressure zone or overpressure danger zone, the power reduction strategy is prioritized. Reducing the stack power can directly reduce the hydrogen consumption rate. Combined with the adjustment of the hydrogen supply valve opening, it can quickly reduce the infeed hydrogen pressure, avoid safety hazards such as excessive pipeline pressure and seal failure caused by the continuous overpressure state, and ensure the safe operation of the stack and hydrogen supply system.

[0064] like Figure 2 As shown, the control method also includes:

[0065] Step S40 involves analyzing the hydrogen pressure change trend based on a pre-defined trend fitting model to predict the zone in which the hydrogen pressure fed into the reactor will fall within a pre-defined time period. This model helps identify patterns in hydrogen pressure changes and avoids reactive responses to pressure anomalies. The trend fitting model is constructed in advance using historical reactor operating data. Input parameters include real-time collected hydrogen pressure data, hydrogen release status data, and current reactor power data. During reactor operation, real-time monitored hydrogen pressure data is continuously input into the trend fitting model. The model calculates and analyzes characteristics such as the slope and frequency of hydrogen pressure changes to predict the trajectory of hydrogen pressure changes within a pre-defined time period, such as the next 5-10 seconds. This determines which zone the hydrogen pressure will fall into among the overpressure danger zone, overpressure zone, operating zone, low-pressure zone, and low-pressure danger zone, providing a basis for early intervention and avoiding lag in control measures.

[0066] Step S41: If the reactor enters the overpressure or low-pressure danger zone, power pre-regulation measures are initiated in advance. When the prediction indicates that the hydrogen pressure entering the reactor will enter the overpressure or low-pressure danger zone within a preset time period, power pre-regulation measures are initiated immediately without waiting for the actual hydrogen pressure to reach the danger threshold. If the overpressure danger zone is predicted, the reactor output power is reduced in advance to reduce hydrogen consumption, and the opening of the hydrogen supply valve is finely adjusted to slow the rate of hydrogen pressure increase and prevent a sudden rise in hydrogen pressure from exceeding the safety threshold. If the low-pressure danger zone is predicted, the power is appropriately reduced in advance to reduce hydrogen demand and avoid a rapid drop in the hydrogen pressure entering the reactor, which could lead to hydrogen starvation. Through this advance intervention, the hydrogen pressure can be controlled within a safe range, reducing the frequency of emergency shutdowns or fault handling, and ensuring the continuity and safety of reactor operation.

[0067] like Figure 3 As shown, the steps for dividing the reactor hydrogen pressure into overpressure hazard zone, overpressure zone, operating zone, low-pressure zone, and low-pressure hazard zone include:

[0068] Step S110: Set the overpressure hazard threshold, overpressure threshold, low pressure threshold, and low pressure hazard threshold. These are set in conjunction with the fuel cell stack's design parameters, safe operation requirements, and actual operating condition verification results. The overpressure hazard threshold is set with reference to the stack's sealing temperature and pressure resistance limits and pipeline safety pressure ratings. Exceeding the overpressure hazard threshold indicates a clear safety risk to the stack. A pressure threshold below the overpressure hazard threshold corresponds to a critical point where, although there is no immediate safety risk, intervention and control are required. The low pressure threshold matches the minimum hydrogen pressure required for efficient stack operation, ensuring that hydrogen supply may be insufficient below this threshold. The low pressure hazard threshold is below the low pressure threshold, corresponding to a critical value where the hydrogen pressure can no longer meet the stack's basic reaction requirements, posing a risk of hydrogen starvation.

[0069] Step S120: The area where the hydrogen pressure fed into the reactor exceeds the overpressure hazard threshold is defined as an overpressure hazard zone. When the real-time data collected by the hydrogen pressure sensor exceeds the overpressure hazard threshold, the hydrogen pressure fed into the reactor is determined to be in the overpressure hazard zone. In this zone, the reactor stack faces the risk of pipeline pressure overload, seal damage, and even hydrogen leakage. This must be treated as a high-priority risk condition, and immediate emergency measures must be taken to prevent the dangerous state from causing irreversible damage to the reactor stack structure and system safety.

[0070] Step S130: The area between the infeed hydrogen pressure and the overpressure danger threshold is defined as the overpressure zone. When the infeed hydrogen pressure is between these two thresholds, it is determined to be in the overpressure zone. In this zone, although there is no immediate safety risk to the fuel cell stack, the hydrogen pressure has exceeded the pressure range required for efficient operation. If not adjusted in time, the hydrogen pressure may continue to rise and enter the overpressure danger zone. Therefore, targeted adjustment actions need to be triggered to bring the hydrogen pressure back to the normal range.

[0071] Step S140: The working region is defined as the hydrogen pressure fed into the stack that is between the low-pressure threshold and the overpressure threshold. When the hydrogen pressure fed into the stack is between these two thresholds, it is determined to be in the working region. Under this region, the hydrogen pressure can meet the hydrogen consumption requirements of the stack at different power outputs, while avoiding efficiency losses and failure risks caused by overpressure or low pressure. It is the ideal pressure range for stack operation.

[0072] Step S150: A low-pressure zone is defined as the area between the infeed hydrogen pressure and the low-pressure threshold. When the infeed hydrogen pressure falls between these two thresholds, it is considered a low-pressure zone. In this zone, the fuel cell stack hydrogen supply shows signs of insufficiency. Continued operation may lead to a hydrogen consumption rate exceeding the supply rate, potentially resulting in hydrogen starvation and entering the low-pressure danger zone. Therefore, timely intervention is necessary to prevent further hydrogen pressure drops.

[0073] Step S160: A low-pressure danger zone is defined as the hydrogen pressure fed into the reactor core being below the low-pressure danger threshold. When the real-time data collected by the hydrogen pressure sensor is lower than the low-pressure danger threshold, the hydrogen pressure fed into the reactor core is determined to be in the low-pressure danger zone. In this zone, the hydrogen supply to the reactor core is insufficient to meet the basic reaction requirements, which can easily lead to hydrogen starvation, resulting in irreversible damage such as single-cell reverse polarity and catalyst corrosion. This must be treated as an emergency risk condition, and rapid measures must be taken to alleviate the hydrogen supply shortage.

[0074] like Figure 4 As shown, the steps for setting the overpressure hazard threshold, overpressure threshold, underpressure threshold, and underpressure hazard threshold include:

[0075] Step S111: Set a first initial value, a second initial value, a third initial value, and a fourth initial value that decrease sequentially. When setting these values, the factory design standards, rated operating parameters, and safety operation manual of the fuel cell stack can be used as the basis. The first initial value corresponds to the basic reference of the overpressure danger threshold, the second initial value corresponds to the basic reference of the overpressure threshold, the third initial value corresponds to the basic reference of the low pressure threshold, and the fourth initial value corresponds to the basic reference of the low pressure danger threshold. The first initial value is greater than the second initial value, which is greater than the third initial value, which is greater than the fourth initial value.

[0076] Step S112: Based on the influence of stack aging, ambient temperature and humidity, and altitude and air pressure on stack operation, update and correct the first, second, third, and fourth initial values. Dynamically optimize the initial values ​​to ensure the thresholds adapt to changes in actual stack operating conditions. During long-term stack operation, stack aging affects its hydrogen pressure resistance, ambient temperature and humidity alter the physical properties of hydrogen, and altitude and air pressure affect the partial pressure of hydrogen. Experiments are conducted to summarize the influence of these factors on stack operation. For example, for every 1000-hour increase in cumulative stack operating time, the first initial value needs to be lowered by 2%-3%; for every 1000-meter increase in altitude, the third initial value needs to be increased by 5%-8%. Based on this, the first to fourth initial values ​​are updated and corrected one by one to ensure the thresholds reflect the real-time operating capability of the stack and avoid the fixed initial values ​​becoming disconnected from actual operating conditions.

[0077] Step S113 involves updating and forming an overpressure hazard threshold based on a first initial value, an overpressure threshold based on a second initial value, a low-pressure threshold based on a third initial value, and a low-pressure hazard threshold based on a fourth initial value. After the update and correction, the first initial value is adapted to the current overpressure tolerance limit of the fuel cell stack, and an overpressure hazard threshold is formed based on the first initial value; the second initial value matches the critical requirements for overpressure early warning of the fuel cell stack, and an overpressure threshold is formed based on the second initial value; the third initial value meets the minimum hydrogen pressure requirements for efficient operation of the fuel cell stack, and a low-pressure threshold is formed based on the third initial value; the fourth initial value corresponds to the critical state of hydrogen starvation risk of the fuel cell stack, and a low-pressure hazard threshold is formed based on the fourth initial value. Through this transformation, the corrected initial values ​​become quantitative standards that can be directly used for determining the hydrogen pressure zoning of the fuel cell stack.

[0078] like Figure 5 As shown, the control method also includes:

[0079] Step S50: Real-time acquisition of first hydrogen pressure data at the hydrogen release source and second hydrogen pressure data at the stack inlet. A first hydrogen pressure sensor is installed at the hydrogen release module outlet (hydrogen release source), and a second hydrogen pressure sensor is installed at the stack inlet pipe (inlet end). Both types of hydrogen pressure data are continuously acquired at a preset acquisition cycle. The first hydrogen pressure data reflects the initial pressure state of the hydrogen source supply, and the second hydrogen pressure data reflects the actual hydrogen pressure state entering the stack. This ensures a comprehensive understanding of the pressure changes in hydrogen from the source to the terminal, avoiding the omission of abnormal pressure along the transmission link due to monitoring only a single node. The acquisition cycle can be once per second.

[0080] Step S51: Calculate the pressure difference between the first hydrogen pressure data and the second hydrogen pressure data; identify potential problems in the hydrogen pressure transmission process by comparing the data. The pressure difference between the real-time collected first and second hydrogen pressure data is calculated. This pressure difference reflects the pressure loss of hydrogen from the hydrogen release source to the reactor inlet, such as pressure attenuation caused by pipeline resistance and valve throttling. Under normal operating conditions, this pressure difference should remain within a relatively stable range. Abnormal fluctuations in the pressure difference indicate problems in the transmission process, such as pipeline blockage or valve jamming.

[0081] Step S52: If the pressure difference exceeds the preset range, adjust the opening of the hydrogen supply valve. The normal range for the pressure difference is pre-set based on the stack piping design parameters, valve specifications, and actual operation verification. For example, the preset range is 5-10 kPa. When the calculated pressure difference exceeds this range, if the pressure difference is too large (e.g., greater than 10 kPa), it may indicate increased pressure loss due to pipe blockage. In this case, the opening of the hydrogen supply valve is appropriately increased to raise the source hydrogen supply pressure and compensate for transmission losses. If the pressure difference is too small (e.g., less than 5 kPa), it may indicate excessive valve opening or pipe leakage. In this case, the opening of the hydrogen supply valve is reduced to avoid insufficient source hydrogen supply pressure or hydrogen waste. Dynamic adjustment ensures that the hydrogen pressure at the stack inlet remains stable within the target range.

[0082] In one embodiment of this application, the step of coordinating the opening degree of the hydrogen supply valve and the output power of the fuel cell stack based on the linkage relationship includes:

[0083] Step S31 involves controlling the hydrogen supply valve opening based on a pulse width modulation (PWM) signal. The adjustment accuracy is ±1% of the valve's maximum opening, and the response period of the fuel cell stack output power regulation is consistent with the hydrogen pressure acquisition period. Pulse Width Modulation (PWM) signals ensure the accuracy of hydrogen supply regulation and guarantee real-time matching between power regulation and hydrogen pressure monitoring. When controlling the hydrogen supply valve opening, a PWM signal output method is used. By adjusting the pulse duty cycle of the signal, the energizing duration of the valve is changed, thereby precisely controlling the valve's opening degree. In actual regulation, the valve opening control accuracy must be stable within ±1% of its maximum opening to avoid fluctuations in the fuel cell stack hydrogen pressure due to excessive valve adjustment errors, ensuring that the hydrogen supply accurately matches the fuel cell stack power requirements. Simultaneously, when regulating the fuel cell stack output power, the response period of power regulation is strictly controlled to maintain consistency with the hydrogen pressure acquisition period. For example, if the hydrogen pressure acquisition cycle is set to 1 second, the power regulation must also complete the entire process from receiving hydrogen pressure data to outputting regulation commands within 1 second, so as to avoid the power adjustment from being out of sync with the actual hydrogen pressure state due to response lag, and to ensure the dynamic balance between hydrogen pressure and power.

[0084] In one embodiment of this application, the control method further includes:

[0085] Step S60: Identify the current operating stage of the fuel cell stack. The operating stages include the open circuit stage, the activation polarization stage, and the normal operation stage. In the open circuit stage, the hydrogen supply valve is kept at its minimum opening and the minimum output power. In the activation polarization stage, the opening of the hydrogen supply valve and the output power of the stack are gradually increased. In the normal operation stage, the opening of the hydrogen supply valve and the output power of the stack are coordinated and controlled according to the linkage relationship.

[0086] The hydrogen pressure and power are adjusted in stages according to the stack's operating characteristics. When identifying the operating stage, a comprehensive judgment is made based on parameters such as the stack's load connection status, output current, and individual cell voltage. The open-circuit stage is characterized by no external load connection and no current output, but the stack has established a stable electrochemical potential. The activation and polarization stage is characterized by a low load connection, small output current, gradual but slow electrochemical reaction, and a slow decrease in individual cell voltage with increasing current. The normal operating stage is characterized by the load reaching the preset operating intensity, a high current density, and efficient and stable electrochemical reactions. In response to the hydrogen consumption characteristics and operational requirements at different stages, during the open-circuit phase, the hydrogen supply valve needs to be kept at its minimum opening to reduce hydrogen waste, while maintaining the minimum output power to ensure the stack is in standby ready state; during the activation and polarization phase, the opening of the hydrogen supply valve needs to be gradually increased to match the growth in reaction hydrogen demand, and the stack output power needs to be gradually increased simultaneously to avoid reaction imbalance caused by sudden changes in hydrogen supply or power; during the normal operation phase, the opening of the hydrogen supply valve and the stack output power are dynamically and collaboratively controlled according to the linkage relationship between the hydrogen release working state and the infeed hydrogen pressure established in this application to ensure that the stack operates stably within the high-efficiency and safe range.

[0087] Furthermore, in high-dust or corrosive environments, to address the issue of data distortion caused by dust accumulation on hydrogen pressure sensors, an abnormal data filtering algorithm can be incorporated into the hydrogen pressure acquisition process. By comparing two adjacent hydrogen pressure data acquisitions, if the data fluctuation exceeds 3 kPa and persists for more than three consecutive times, the current sensor data is determined to be abnormal, and the system automatically switches to a backup hydrogen pressure sensor. The algorithm also predicts the current hydrogen pressure status based on the hydrogen pressure change trend, avoiding control actions triggered by misjudgments. Simultaneously, if the infeed hydrogen pressure frequently falls into the low-pressure zone, such as more than five times per hour, it is determined that there is a risk of dust blockage in the hydrogen supply pipeline, and a periodic pulsed hydrogen supply program is initiated. For example, the hydrogen supply valve is controlled to rapidly open and close 3-5 times within 1 second, using the instantaneous change in hydrogen flow rate to clear dust accumulation in the pipeline. After each pulsed hydrogen supply, the hydrogen pressure recovery is monitored until the frequency of low-pressure zones drops to less than once per hour.

[0088] In low-temperature and frigid environments, such as temperatures below -20°C, to prevent hydrogen liquefaction and pipeline freezing, when the hydrogen pressure entering the stack is in the low-pressure zone, the hydrogen supply pipeline heating device and the stack preheating program are started simultaneously to raise the stack temperature to above 0°C. Then, the opening of the hydrogen supply valve is gradually increased to avoid hydrogen supply interruption caused by the hydrogen supply valve jamming or hydrogen liquefaction at low temperatures.

[0089] In long-term standby scenarios, to reduce energy consumption and avoid catalyst aging caused by frequent start-stop cycles, the system automatically switches to an ultra-low power mode: the hydrogen pressure sampling frequency is reduced from the usual 1 second / time to 5 seconds / time, the hydrogen supply valve is maintained at its minimum opening of 10%-15%, and unnecessary auxiliary modules, such as the high-frequency purging system, are shut down. Every 30 minutes, the system briefly initiates power regulation, increasing the power to 5% of the rated power and maintaining it for 10 seconds, while monitoring the stack reaction activity and hydrogen pressure response to ensure that the stack can be put into normal operation at any time in standby mode.

[0090] like Figure 6 As shown, this application also provides a control system for hydrogen pressure in a fuel cell, the control system including: a partitioning module 10, a construction module 20 and a regulation module 30.

[0091] The classification module 10 is used to classify the hydrogen release working state into sufficient hydrogen release and insufficient hydrogen release, and to classify the hydrogen pressure at the reactor core into overpressure hazard zone, overpressure zone, working zone, low pressure zone, and low pressure hazard zone. The classification module 10 receives data such as pressure and flow rate from the hydrogen release module and combines it with preset hydrogen release capacity judgment criteria to clearly classify the hydrogen release working state into two categories: sufficient hydrogen release and insufficient hydrogen release, reflecting the actual supply capacity of the hydrogen source. At the same time, based on the system's preset overpressure hazard threshold, overpressure threshold, low pressure threshold, and low pressure hazard threshold, it analyzes the real-time data collected by the hydrogen pressure sensor at the reactor core and divides the hydrogen pressure at the reactor core into five intervals: overpressure hazard zone, overpressure zone, working zone, low pressure zone, and low pressure hazard zone, to achieve a refined classification of hydrogen pressure status.

[0092] Module 20 is used to establish the linkage between the hydrogen release operating state and the infeed hydrogen pressure. This linkage adapts to the hydrogen release output characteristics and the fuel cell stack power requirements. Based on the operating characteristics of the fuel cell stack, and combining the hydrogen release module's output pressure, flow rate, and other hydrogen release output characteristics, as well as the stack's power demand patterns under different operating conditions, Module 20 integrates historical operating data and experimental verification results to construct the linkage between the hydrogen release operating state and the infeed hydrogen pressure. This linkage regulation clarifies the control direction corresponding to different hydrogen release states and different infeed hydrogen pressure zones, ensuring that subsequent regulation can both match the hydrogen release supply capacity and meet the stack's power output requirements, avoiding supply-demand imbalances caused by single-mode regulation.

[0093] The control module 30 is used to collect real-time hydrogen release status and in-stack hydrogen pressure, and coordinately control the opening of the hydrogen supply valve and the stack output power based on the linkage relationship. On the one hand, the control module 30 continuously collects hydrogen release status data and in-stack hydrogen pressure data by connecting the pressure sensor, flow sensor and in-stack hydrogen pressure sensor of the hydrogen release module, to achieve real-time monitoring of the entire hydrogen pressure link status; on the other hand, based on the linkage relationship established by the construction module, it synchronously sends instructions to the hydrogen supply valve control unit and the stack power control unit to coordinately control the opening of the hydrogen supply valve and the stack output power. For example, when the in-stack hydrogen pressure is overpressured, the valve opening is reduced and the power is reduced synchronously; when the hydrogen pressure is low and hydrogen release is insufficient, the valve opening is adjusted appropriately and the power is reduced; when hydrogen release is sufficient and the hydrogen pressure is normal, the hydrogen supply and power parameters are maintained or optimized to achieve dynamic balance between hydrogen pressure and power, ensuring stable operation of the stack.

[0094] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be covered within the scope of the claims and specification of the present invention.

Claims

1. A method for controlling hydrogen pressure in a fuel cell, characterized in that, The control method includes: The hydrogen release working state is divided into sufficient hydrogen release and insufficient hydrogen release, and the hydrogen pressure at the reactor core is divided into overpressure danger zone, overpressure zone, working zone, low pressure zone and low pressure danger zone. Establish a linkage relationship between the hydrogen release operating state and the hydrogen pressure fed into the stack, wherein the linkage relationship is adapted to the hydrogen release output characteristics and the power requirements of the fuel cell stack; The hydrogen release status and the hydrogen pressure fed into the stack are collected in real time, and the opening degree of the hydrogen supply valve and the output power of the stack are coordinated and controlled based on the aforementioned linkage.

2. The control method according to claim 1, characterized in that, The steps for establishing the linkage between the hydrogen release operating state and the reactor hydrogen pressure include: A linkage relationship is constructed based on a preset association table, wherein the association table records the corresponding stack power control strategies for different hydrogen release operating states and different infeed hydrogen pressures.

3. The control method according to claim 2, characterized in that, The power control strategy of the fuel cell stack includes power boosting, power maintenance, and power reduction. When hydrogen release is sufficient and the infeed hydrogen pressure is within the operating range, power maintenance or power boost is performed. When hydrogen release is insufficient and the hydrogen pressure at the reactor core is in a low-pressure or low-pressure danger zone, the operating power is reduced. When the infeed hydrogen pressure is in the overpressure zone or overpressure danger zone, the execution power is reduced.

4. The control method according to claim 1, characterized in that, The control method further includes: Based on the pre-set trend fitting model, the hydrogen pressure change trend is analyzed, and the zone of the infeed hydrogen pressure in the future within a pre-set time period is predicted. If the system enters an overpressure or low-pressure danger zone, power pre-regulation measures should be initiated in advance.

5. The control method according to claim 1, characterized in that, The steps for dividing the reactor feed hydrogen pressure into overpressure hazard zone, overpressure zone, operating zone, low-pressure zone, and low-pressure hazard zone include: Set overpressure hazard threshold, overpressure threshold, underpressure threshold, and underpressure hazard threshold; A region where the hydrogen pressure at the reactor core exceeds the overpressure hazard threshold is defined as an overpressure hazard zone. The overpressure zone is defined as the hydrogen infeed pressure between the overpressure threshold and the overpressure danger threshold. The working zone is defined as the hydrogen infeed pressure between the low pressure threshold and the overpressure threshold. A low-pressure zone is defined as a reactor hydrogen pressure between the low-pressure danger threshold and the low-pressure threshold. A low-pressure hazard zone is defined as a hydrogen pressure below the low-pressure hazard threshold.

6. The control method according to claim 5, characterized in that, The steps for setting the overpressure hazard threshold, overpressure threshold, underpressure threshold, and underpressure hazard threshold include: Set a first, second, third, and fourth initial value that decreases sequentially; Based on the influence of fuel cell stack aging degree, ambient temperature and humidity, and altitude and air pressure on fuel cell stack operation, the first initial value, the second initial value, the third initial value, and the fourth initial value are updated and corrected. An overpressure danger threshold is formed based on the first initial value, an overpressure threshold is formed based on the second initial value, a low pressure threshold is formed based on the third initial value, and a low pressure danger threshold is formed based on the fourth initial value.

7. The control method according to claim 1, characterized in that, The control method further includes: Real-time acquisition of the first hydrogen pressure data at the hydrogen release source and the second hydrogen pressure data at the reactor inlet; Calculate the pressure difference between the first hydrogen pressure data and the second hydrogen pressure data; If the pressure difference exceeds the preset range, the adjustment range of the hydrogen supply valve opening will be adjusted.

8. The control method according to claim 1, characterized in that, The steps for coordinating and controlling the hydrogen supply valve opening and the fuel cell stack output power based on the aforementioned linkage relationship include: The hydrogen supply valve opening is controlled based on pulse width modulation signals, with an adjustment accuracy of ±1% of the maximum valve opening, and the response period of the stack output power regulation is consistent with the hydrogen pressure acquisition period.

9. The control method according to claim 1, characterized in that, The control method further includes: Identify the current operating stage of the fuel cell stack, which includes the open circuit stage, the activation polarization stage, and the normal operation stage; Specifically, during the open-circuit phase, the hydrogen supply valve is maintained at its minimum opening and output power; during the activation and polarization phase, the opening of the hydrogen supply valve and the output power of the fuel cell stack are gradually increased; and during the normal operation phase, the opening of the hydrogen supply valve and the output power of the fuel cell stack are coordinated and regulated according to the aforementioned linkage relationship.

10. A control system for hydrogen pressure in a fuel cell, characterized in that, The control system includes: The partitioning module is used to divide the hydrogen release working state into sufficient hydrogen release and insufficient hydrogen release, and to divide the infeed hydrogen pressure into overpressure danger zone, overpressure zone, working zone, low pressure zone and low pressure danger zone. A construction module is used to establish the linkage between the hydrogen release working state and the hydrogen pressure fed into the stack, wherein the linkage is adapted to the hydrogen release output characteristics and the power requirements of the fuel cell stack. The control module is used to collect the hydrogen release status and the hydrogen pressure fed into the stack in real time, and to coordinate the opening of the hydrogen supply valve and the output power of the stack based on the aforementioned linkage.

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