Method for regulating the output power of a fuel cell and control system therefor

Abstract

This invention discloses a method and control system for regulating the output power of a fuel cell. The regulation method includes: dividing the ambient temperature into multiple temperature ranges; setting power constraints for each temperature range based on a pre-established temperature-power model; quantifying the compensation coefficient between altitude and output power based on a pre-established altitude-power model; establishing multi-dimensional linkage rules based on the power constraints, compensation coefficients, and the operating state of the fuel cell; and dynamically adjusting the output power of the fuel cell according to the linkage rules. The technical solution of this application can effectively stabilize the output power and improve the operating efficiency, service life, and safety of the fuel cell.

Description

Technical Field

[0001] This invention relates to the field of fuel cell testing technology, and more specifically to a method for regulating the output power of a fuel cell and its control system. 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 practical applications, the operating environment of fuel cells experiences fluctuations in temperature and altitude. Temperature changes directly affect the stack's reaction kinetics, material stability, and thermal management efficiency, while increased altitude leads to decreased atmospheric pressure and insufficient oxygen supply, both of which cause the fuel cell's output power to deviate from its rated value. Simultaneously, the fuel cell's output power is also susceptible to fluctuations in its own operating conditions. Existing control technologies have failed to adequately consider the coupling of multiple environmental factors and the coordinated adaptation to the stack's operating state, resulting in insufficient power control precision and response lag. This makes it difficult to maintain stable output power under complex operating conditions, thereby affecting the fuel cell's operating efficiency, lifespan, and safety performance. Summary of the Invention

[0003] To address the shortcomings of existing technologies, this invention provides a method for regulating the output power of a fuel cell, which can effectively stabilize the output power and improve the operating efficiency, service life, and safety of the fuel cell.

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

[0005] The ambient temperature is divided into multiple temperature ranges, and power constraints are set for each temperature range based on a pre-established temperature power model.

[0006] Based on a pre-established altitude power model, the compensation coefficient between altitude and output power is quantified.

[0007] A multi-dimensional linkage rule is established based on the power constraint, the compensation coefficient, and the operating status of the fuel cell;

[0008] The output power of the fuel cell is dynamically adjusted according to the aforementioned linkage rules.

[0009] In one aspect, the temperature range includes a low-temperature working zone, a reference working zone, a high-temperature working zone, and an over-temperature working zone, with temperatures increasing sequentially.

[0010] The steps for setting power constraints for each temperature range include:

[0011] Maintain power output within the reference operating range;

[0012] Determine the degree of deviation between the low-temperature working zone and the high-temperature working zone and the reference working zone, and set a gradient increase or decrease in power according to the degree of deviation;

[0013] The output power is adjusted according to the preset emergency control range in the over-temperature operating zone.

[0014] In one aspect, the step of determining the degree of deviation between the low-temperature operating zone and the high-temperature operating zone from the reference operating zone, and setting a gradient increase or decrease in power according to the degree of deviation, includes:

[0015] Set the reference temperature of the reference working area;

[0016] Collect the real-time temperature of the low-temperature working area or the high-temperature working area, calculate the absolute difference between the real-time temperature and the reference temperature, and quantify the degree of deviation using the absolute difference.

[0017] The numerical range of the deviation is divided into multiple gradient levels, and the temperature difference range corresponding to each gradient level is determined.

[0018] A corresponding power adjustment range is matched for each gradient level, wherein the greater the deviation, the larger the absolute value of the corresponding power adjustment range.

[0019] In one aspect, the step of adjusting the output power in the over-temperature operating zone according to a preset emergency control range includes:

[0020] Obtain the over-temperature threshold and emergency control power range;

[0021] The ambient temperature and the temperature of the fuel cell stack are collected in real time. When the ambient temperature of the fuel cell stack is greater than the over-temperature threshold, it is confirmed that the fuel cell stack has entered the over-temperature working zone.

[0022] Reduce the output power to the emergency control power range.

[0023] In one aspect, the steps of quantifying the compensation coefficient between altitude and output power based on a pre-established altitude power model include:

[0024] Set a standard reference operating condition, record the rated output power of the fuel cell stack under the standard reference operating condition, and calibrate the reference coefficient using the rated output power;

[0025] Based on the aforementioned baseline coefficient, and according to the attenuation law of altitude and atmospheric pressure, a mapping relationship between altitude and compensation coefficient is established.

[0026] The compensation coefficient is corrected based on the stack's operating status.

[0027] In one aspect, the stack operating status includes membrane humidity and catalyst activity parameters;

[0028] The step of correcting the compensation coefficient based on the stack operating status includes:

[0029] If the membrane humidity is lower than the humidity threshold, the attenuation rate of the compensation coefficient is increased proportionally.

[0030] If the catalyst activity decays beyond a set threshold, the upper limit of the compensation coefficient in the high-altitude region will be reduced.

[0031] In one aspect, the operating state of the fuel cell includes a hydrogen pressure zoning state, which includes an overpressure danger zone, an overpressure zone, a normal operating zone, a low-pressure zone, and a low-pressure danger zone with gradually decreasing pressure.

[0032] The step of dynamically adjusting the output power of the fuel cell according to the aforementioned linkage rules includes:

[0033] In the overpressure danger zone or the overpressure zone, the output power is reduced by the magnitude of the hydrogen pressure exceeding the normal operating zone.

[0034] In the low-pressure area or the low-pressure danger zone, the upper limit of the power increase is reduced by a preset ratio;

[0035] In the normal operating range, the output power is dynamically adjusted based on the current temperature and altitude parameters.

[0036] In one aspect, the step of dynamically adjusting the output power of the fuel cell according to the linkage rule further includes:

[0037] Based on the maximum allowable rate of change of current in the fuel cell stack, and in conjunction with the power constraints and the compensation coefficients, a multi-factor power ramp control relationship is constructed.

[0038] In one aspect, the step of dynamically adjusting the output power of the fuel cell according to the linkage rule further includes:

[0039] Based on the target output power determined by the linkage rule, the opening of the hydrogen supply valve is adjusted to match the hydrogen supply volume corresponding to the current power requirement.

[0040] Adjust the cooling fan speed according to the temperature difference between the fuel cell stack and the ambient temperature;

[0041] The purging time and interval are dynamically adjusted based on membrane humidity detection data.

[0042] Furthermore, to address the aforementioned problems, this application also provides a fuel cell output power regulation system, the regulation system comprising:

[0043] The setting module is used to divide the ambient temperature into multiple temperature ranges and set the power constraints for each temperature range based on a pre-established temperature power model.

[0044] The quantization module is used to quantify the compensation coefficient between altitude and output power based on a pre-established altitude power model.

[0045] A module is established to create multi-dimensional linkage rules based on the power constraints, the compensation coefficients, and the operating status of the fuel cell.

[0046] The adjustment module is used to dynamically adjust the output power of the fuel cell according to the linkage rules.

[0047] The beneficial effects of this invention are as follows: It divides the ambient temperature into multiple ranges and sets power constraints based on a temperature-power model to adapt to the reaction characteristics of the fuel cell stack at different temperatures, reducing power deviations caused by insufficient reaction at low temperatures and heat accumulation at high temperatures; it quantifies the compensation coefficient through an altitude-power model and corrects the output power according to the attenuation law of altitude and atmospheric pressure, reducing power mismatch problems caused by insufficient oxygen supply at high altitudes; it establishes multi-dimensional linkage rules based on the fuel cell operating status and dynamically adjusts the output power, achieving coordinated adaptation between environmental factors and the stack's own state, improving the accuracy and response speed of power regulation under complex operating conditions, ensuring the stability of fuel cell operation, and thus improving the operating efficiency, service life, and safety of the fuel cell. Attached Figure Description

[0048] 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.

[0049] Figure 1 This is a schematic diagram of the process steps for regulating the output power of the fuel cell in this application;

[0050] Figure 2 This is a schematic diagram illustrating the process steps for setting power constraints for each temperature range in the control method of this application.

[0051] Figure 3 This is a schematic diagram of the process steps for setting the gradient increase or decrease of power in the control method of this application;

[0052] Figure 4 This is a schematic diagram of the emergency output power control process steps in the control method of this application;

[0053] Figure 5This is a schematic diagram of the process steps for quantifying the compensation coefficient between altitude and output power in the control method of this application;

[0054] Figure 6 This is a schematic diagram of the process steps for correcting the compensation coefficient in the control method of this application;

[0055] Figure 7 This is a schematic diagram of the process steps for dynamically adjusting the output power of the fuel cell in the control method of this application;

[0056] Figure 8 This is a schematic diagram of the process steps of another embodiment of the control method for dynamically adjusting the output power of a fuel cell in this application;

[0057] Figure 9 This is a schematic diagram of the functional modules of the fuel cell output power regulation system of this application. Detailed Implementation

[0058] 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.

[0059] 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.

[0060] This application provides a method for regulating the output power of 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, and has high energy conversion efficiency and clean emissions.

[0061] A typical fuel cell stack consists of multiple individual cells connected in series. Each individual cell includes an anode, a cathode, and an electrolyte membrane. After hydrogen gas is introduced into the anode, it decomposes into protons under the action of a catalyst. ) and electrons ( Electrons pass through an external circuit to form an electric current, while protons migrate through the electrolyte membrane to the cathode. Simultaneously, oxygen (or air) is introduced into 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.

[0062] like Figure 1 As shown, the control method of this application includes:

[0063] Step S10: Divide the ambient temperature into multiple temperature ranges. Based on the pre-established temperature-power model, set power constraints for each temperature range. Combining the reaction kinetics characteristics, material tolerance limits, and thermal management efficiency thresholds of the fuel cell stack, divide the ambient temperature into multiple ranges under full operating conditions and determine the temperature boundary parameters for each range. Simultaneously, construct a temperature-power model through temperature and power matching tests. The temperature-power model pre-stores data such as the safe output power range and power adjustment priority of the stack under different temperature ranges. Based on the temperature-power model, set targeted power constraints for each temperature range to ensure that the power output adapts to changes in reaction efficiency and safety risks caused by temperature changes.

[0064] Specifically, for the temperature-power model, the establishment process is illustrated with an example. Three fuel cell stacks of the same model are selected as test samples. The parameters such as the hydrogen pressure (0.2-0.3 MPa), hydrogen purity (99.97%), and excess air coefficient (2.0-2.5) are controlled as constant values, while the ambient temperature variable is changed. The temperature adjustment range covers -40℃ (low temperature limit) to 85℃ (supercritical temperature). 30 temperature gradients are set at 5℃ intervals, and each gradient is operated stably for 30 minutes to ensure data stability.

[0065] Real-time data such as the output power of the fuel cell stack, the standard deviation of the single-chip voltage, the temperature of the fuel cell stack body, and the reaction polarization curve are collected under each temperature gradient. Five sets of samples are collected for each temperature gradient, and the average value is taken after removing outliers.

[0066] The model function is constructed using a multiple linear regression algorithm: P=aT 2 +bT+c, where P is the upper limit of output power corresponding to the temperature, T is the ambient temperature, and a, b, and c are fitting coefficients. Subsequently, the power prediction value was verified through 10 temperature points that were not involved in the fitting (such as -35℃, 12℃, 78℃, etc.). The error between the predicted power value and the actual value is less than 3%, which meets the accuracy requirements for engineering applications.

[0067] The fitting coefficients, power safety range, adjustment priority, and other parameters for different temperature ranges are stored in the model database. When called, the corresponding range is matched with the real-time temperature, and the power constraint value is automatically output.

[0068] Step S20: Based on the pre-established altitude power model, quantify the compensation coefficient between altitude and output power; establish the correlation between altitude and output power compensation coefficient through the altitude power model. The altitude power model is based on the physical law of atmospheric pressure decay with altitude increase, combined with the oxygen requirements of the fuel cell stack and power output characteristics. First, calibrate the baseline value of the compensation coefficient under the baseline operating condition; then, through full-load testing under multiple altitude gradients, collect atmospheric pressure, maximum safe output power of the fuel cell stack, and polarization state data corresponding to different altitudes, and quantify the compensation coefficient for each altitude range.

[0069] Step S30 establishes multi-dimensional linkage rules based on power constraints, compensation coefficients, and the operating status of the fuel cell. This multi-factor collaborative regulation overcomes the limitations of single-factor regulation by deeply coupling power constraints, compensation coefficients, and the real-time operating status of the fuel cell to construct multi-dimensional linkage rules. These rules define the power adjustment steps under different operating conditions, such as the priority of power constraints when high temperature and high altitude are combined, the power adjustment range adapted to temperature / altitude when hydrogen pressure is abnormal, and the power limitation conditions when polarization intensifies. This ensures that power adjustment can simultaneously respond to changes in the external environment and fluctuations in the internal operating status, achieving precise regulation.

[0070] Step S40: Dynamically adjust the fuel cell output power according to the linkage rules. Based on multi-dimensional linkage rules, real-time environmental parameters such as temperature and altitude, as well as fuel cell stack operating status data, are received. The output power under the current operating conditions is determined through rule matching. This achieves dynamic and stable control of the fuel cell output power, balancing operating efficiency, safety, and lifespan.

[0071] In this embodiment, the ambient temperature is divided into multiple ranges, and power constraints are set based on a temperature-power model to adapt to the reaction characteristics of the fuel cell stack at different temperatures, reducing power deviations caused by insufficient reaction at low temperatures and heat accumulation at high temperatures. The compensation coefficient is quantified through an altitude-power model, and the output power is corrected according to the attenuation law of altitude and atmospheric pressure, reducing power mismatch problems caused by insufficient oxygen supply at high altitudes. Multi-dimensional linkage rules are established in conjunction with the fuel cell operating status, and the output power is dynamically adjusted to achieve coordinated adaptation between environmental factors and the state of the fuel cell stack itself. This improves the accuracy and response speed of power regulation under complex operating conditions, ensures the stability of fuel cell stack operation, and thus improves the operating efficiency, service life, and safety of the fuel cell.

[0072] like Figure 2 As shown, the temperature range includes the low-temperature working zone, the reference working zone, the high-temperature working zone, and the over-temperature working zone, with temperatures increasing sequentially.

[0073] The steps for setting power constraints for each temperature range include:

[0074] Step S110: Maintain power output within the reference operating range. The power constraint of the reference operating range is set to maintain the rated output power, meaning no additional power increase or decrease is required. This ensures that the fuel cell stack operates stably and efficiently at the appropriate temperature, fully utilizing its performance. The reference operating range can be 25-35℃.

[0075] Step S120: Determine the degree of deviation between the low-temperature operating zone and the high-temperature operating zone from the reference operating zone, and set a gradient increase or decrease in power according to the degree of deviation; use the reference operating zone temperature as a benchmark and as a quantitative reference for the degree of deviation; collect the ambient temperature of the fuel cell in the low-temperature or high-temperature operating zone in real time, calculate the absolute difference between the real-time temperature and the reference temperature, and use this to quantify the degree of temperature deviation from the benchmark; divide the degree of deviation into multiple gradient levels, such as 5℃, 10℃, and 15℃, which correspond to different levels, and match a corresponding power adjustment range for each gradient level. The greater the degree of deviation, the greater the absolute value of the adjustment range. In the low-temperature zone, gradient power reduction reduces component damage caused by insufficient response, and in the high-temperature zone, gradient power reduction suppresses performance degradation caused by heat accumulation.

[0076] Step S130: Adjust the output power in the over-temperature operating zone according to the preset emergency control range. Based on the fuel cell material's tolerance limit and the maximum heat dissipation capacity of the thermal management system, pre-set the over-temperature threshold and emergency control power range. The over-temperature threshold is set to be 15°C higher than the upper limit of the baseline operating zone, and the emergency control power range is set to 30%-50% of the rated power. The ambient temperature of the fuel cell is monitored in real time using a temperature sensor. When the temperature continuously exceeds the over-temperature threshold, confirming entry into the over-temperature operating zone, emergency control is immediately triggered, rapidly reducing the output power to the preset emergency control power range to minimize irreversible damage caused by high temperatures, such as degradation of the fuel cell membrane material and catalyst deactivation.

[0077] like Figure 3 As shown, the steps for determining the degree of deviation between the low-temperature operating zone and the high-temperature operating zone and the reference operating zone, and setting a gradient increase or decrease in power according to the degree of deviation, include:

[0078] Step S121: Set the reference temperature of the reference working area; combine the reaction kinetics range of the fuel cell stack, the peak range of material stability and the thermal management adaptation threshold, determine the temperature range of the reference working area through operating condition testing, and calibrate the core reference temperature from it. For example, select 30℃ in the 25-35℃ range as the reference temperature. The reference temperature provides a unified reference standard for quantifying the deviation of the low temperature and high temperature working areas.

[0079] Step S122: Collect the real-time temperature of the low-temperature working area or the high-temperature working area, calculate the absolute difference between the real-time temperature and the reference temperature, and quantify the degree of deviation by using the absolute difference; collect the real-time temperature data of the low-temperature working area or the high-temperature working area in real time through the temperature sensor; calculate the absolute difference between the real-time temperature data and the reference temperature, and quantify the degree of temperature deviation from the reference working area by using the difference. The larger the difference, the more significant the influence of the current temperature on the fuel cell stack reaction characteristics.

[0080] Step S123: Divide the numerical range of deviation into multiple gradient levels and determine the temperature difference range corresponding to each gradient level; based on the fuel cell stack performance test data, analyze the influence of different temperature deviation differences on power output stability and response efficiency, and divide the numerical range of deviation into multiple gradient levels. For example, a difference of 0-5℃ is level one, 5-10℃ is level two, 10-15℃ is level three, etc., and determine the specific temperature difference range corresponding to each gradient level.

[0081] Step S124: Match a corresponding power adjustment range to each gradient level. The greater the deviation, the larger the absolute value of the corresponding power adjustment range. Based on the impact of temperature deviation on the fuel cell stack at each gradient level, combined with the fuel cell stack's safe operation threshold and power control accuracy requirements, a dedicated power adjustment range is matched to each gradient level. The degree of deviation is positively correlated with the absolute value of the adjustment range; that is, the further the temperature deviates from the baseline, the larger the power adjustment range. In the low-temperature operating range, the focus is on reducing insufficient response and component damage by adjusting the power gradient downwards, while in the high-temperature operating range, the focus is on suppressing heat accumulation and performance degradation by adjusting the power gradient downwards, thus achieving adaptation between temperature deviation and power adjustment.

[0082] like Figure 4 As shown, the steps for adjusting the output power according to the preset emergency control range in the over-temperature operating range include:

[0083] Step S131: Obtain the over-temperature threshold and emergency control power range; combining the material tolerance limit of the fuel cell stack, the maximum heat dissipation capacity of the thermal management system, and long-term operational reliability data, determine the over-temperature threshold through multiple sets of high-temperature operating condition tests. The over-temperature threshold is the critical temperature value for safe operation of the stack. When the temperature is below the over-temperature threshold, the stack is controlled by conventional power constraint; when it is above the threshold, emergency intervention is required. At the same time, based on the reaction limit of the stack under high-temperature environment, the adaptability of hydrogen and oxygen supply, and the polarization suppression requirements, set the emergency control power range to ensure that the stack can maintain basic operation while reducing reaction heat generation.

[0084] Step S132: Real-time acquisition of the ambient temperature and the body temperature of the fuel cell stack. When the ambient temperature exceeds the over-temperature threshold, it is confirmed that the stack has entered the over-temperature working zone. Real-time acquisition of dual-dimensional temperature data is achieved through ambient temperature sensors around the stack and body temperature sensors embedded inside the stack. The acquired ambient temperature is compared with the over-temperature threshold in real time. If the ambient temperature continues to exceed the over-temperature threshold, the stack is determined to have entered the over-temperature working zone, triggering subsequent emergency control to reduce the irreversible damage to the stack caused by the continuous impact of high temperature.

[0085] Step S133: Reduce the output power to the emergency control power range. Upon confirming entry into the over-temperature operating zone, immediately initiate the emergency power control command. Based on the preset emergency control power range, rapidly adjust the fuel cell stack's output power parameters to directly reduce the power to the appropriate value within the range. During the reduction process, ensure the speed and stability of power adjustment, reduce voltage fluctuations caused by sudden power drops, and simultaneously reserve sufficient heat dissipation response time for the thermal management system. By reducing power, reduce reaction heat generation, and work in conjunction with the heat dissipation system, drive the fuel cell stack temperature to quickly drop back to a safe range.

[0086] like Figure 5 As shown, the steps for quantifying the compensation coefficient between altitude and output power based on a pre-established altitude power model include:

[0087] Step S210: Set a standard reference operating condition and record the rated output power of the fuel cell stack under the standard reference operating condition. Use the rated output power to calibrate the reference coefficient. Combine fuel cell industry standards and fuel cell stack design rated parameters to set a standard reference operating condition, which is usually a standard atmospheric environment with an altitude of 0 meters, an atmospheric pressure of 101.3 kPa, an ambient temperature of 25°C, and a relative humidity of 50%. Start the fuel cell stack under the standard reference operating condition and make it run stably. Record the rated output power of the fuel cell stack through power detection. Use the rated output power as a reference and calibrate the compensation coefficient as the reference coefficient. The reference coefficient is usually set to 1.0 to ensure that the fuel cell stack can run stably at full load without additional power correction under the reference operating condition.

[0088] Step S220: Based on the baseline coefficient, a mapping relationship between altitude and compensation coefficient is established according to the attenuation law of altitude and atmospheric pressure. Based on the nonlinear attenuation law of atmospheric pressure with increasing altitude in atmospheric physical characteristics, and combined with the principle of fuel cell stack reaction kinetics, an altitude power model is constructed based on the baseline coefficient. The principle of fuel cell stack reaction kinetics is that the oxygen partial pressure decreases with decreasing atmospheric pressure, which directly affects the fuel cell stack output power. Full-load tests are conducted at different altitude gradients, such as 500 meters, 1000 meters, 2000 meters, and 3000 meters, to collect data on atmospheric pressure, maximum safe output power of the fuel cell stack, and polarization state at each altitude. Based on the test data, a data fitting algorithm is used to establish a mapping relationship between altitude and compensation coefficient, so that the compensation coefficient decreases adaptively with increasing altitude, ensuring that the compensation coefficient at different altitudes can accurately reflect the impact of oxygen supply capacity on power.

[0089] Step S230: Correct the compensation coefficient based on the stack's operating status. Real-time monitoring of stack operating parameters, including electrolyte membrane humidity, catalyst activity decay, single-cell voltage fluctuation, and infeed hydrogen pressure stability, is performed. If membrane humidity is detected to be below a preset threshold, which could lead to a decrease in proton conduction efficiency, the decay rate of the compensation coefficient is increased proportionally to reduce excessive power and thus prevent membrane dryness damage. If catalyst activity decay exceeds a set range, which could lead to incomplete reactions, the upper limit of the compensation coefficient in high-altitude regions is further reduced to prevent increased polarization damage. Simultaneously, the compensation coefficient is corrected based on real-time ambient temperature and humidity data to ensure it matches both the oxygen supply capacity at the current altitude and the stack's own operating status.

[0090] like Figure 6 As shown, the stack operating status includes membrane humidity and catalyst activity parameters.

[0091] The steps for correcting the compensation coefficient based on the stack operating status include:

[0092] Step S231: If the membrane humidity is lower than the humidity threshold, the decay rate of the compensation coefficient is increased proportionally. The humidity data of the electrolyte membrane is monitored in real time. When the membrane humidity is detected to be lower than the humidity threshold, it indicates that the current proton conduction capacity has decreased. If the original decay rate of the compensation coefficient is maintained, it is easy to cause a mismatch between the power requirement and the membrane conduction efficiency, which may lead to membrane dry damage or increased polarization. At this time, the decay rate of the compensation coefficient is increased proportionally to make the rate of decrease of the compensation coefficient with the increase of altitude faster, thereby reducing the target output power at the corresponding altitude, reducing the reaction intensity to alleviate membrane humidity consumption, and realizing dynamic adaptation between the compensation coefficient and the membrane conduction state.

[0093] Step S232: If the catalyst activity decay exceeds the set threshold, reduce the upper limit of the compensation coefficient in the high-altitude range. By monitoring parameters such as the voltage stability of a single stack cell and the reaction polarization curve, the catalyst activity state is evaluated and an activity decay threshold is set. When the catalyst activity decay exceeds the decay threshold, its ability to catalyze hydrogen oxidation and oxygen reduction decreases. Insufficient oxygen supply in high-altitude environments will further exacerbate the problem of incomplete reaction. At this time, the upper limit of the compensation coefficient in the high-altitude range is reduced in a targeted manner, so that the target output power at high altitudes is further reduced, reducing catalyst overload caused by excessive power, slowing down the activity decay rate, and ensuring the operational stability of the stack under high-altitude and catalyst decay conditions.

[0094] like Figure 7 As shown, the operating states of a fuel cell include the infeed hydrogen pressure zone state, which includes the overpressure danger zone, overpressure zone, normal operation zone, low pressure zone, and low pressure danger zone, where the pressure gradually decreases.

[0095] The steps for dynamically adjusting the output power of a fuel cell according to the linkage rules include:

[0096] Step S410: In the overpressure danger zone or overpressure zone, the output power is reduced according to the magnitude of hydrogen pressure exceeding the normal operating zone; preset thresholds for the division of the overpressure danger zone, overpressure zone, and normal operating zone of the hydrogen pressure entering the stack are used to determine the judgment standard for the hydrogen pressure exceeding the normal operating zone in each overpressure zone; real-time monitoring of the hydrogen pressure data entering the stack is conducted, and when the hydrogen pressure is determined to be in the overpressure danger zone or overpressure zone, the fuel cell output power is reduced synchronously according to the actual hydrogen pressure exceeding the limit and the preset power adjustment ratio. The greater the exceeding limit, the more significant the power reduction. By reducing the power, the stack reaction intensity is reduced, the hydrogen and oxygen supply balance is matched under overpressure conditions, and the safety risks such as gas channeling and membrane damage caused by high pressure are reduced.

[0097] Step S411: In the low-pressure zone or low-pressure danger zone, reduce the upper limit of power increase by a preset ratio; preset the threshold values ​​for the low-pressure zone and low-pressure danger zone of the hydrogen pressure entering the stack, as well as the reference value for the upper limit of power increase; when the hydrogen pressure entering the stack is detected to be in the low-pressure zone or low-pressure danger zone, it is determined that the current hydrogen supply capacity is insufficient. If the original power increase rate is maintained, it is easy to cause incomplete reaction and increased polarization; at this time, reduce the upper limit of power increase by a preset ratio to limit the rapid increase of power, and at the same time prohibit the power requirement exceeding the current hydrogen supply capacity, so as to ensure that the power increase is compatible with the hydrogen supply capacity and ensure the stability of the stack operation. The preset ratio is, for example, 30%-50%.

[0098] Step S412: In the normal operating range, dynamically adjust the output power based on the current temperature and altitude parameters. When the hydrogen pressure fed into the stack is within the normal operating range, it indicates that the hydrogen supply is stable. At this time, the power constraint and compensation coefficient are used as the basis for regulation. The power constraint requirements corresponding to the current ambient temperature range are obtained in real time, and the target power range is calculated by combining the compensation coefficient corresponding to the altitude. The output power is dynamically fine-tuned based on the real-time operating status of the stack, so that the power can adapt to the environmental coupling requirements of temperature and altitude, and can give full play to the operating efficiency of the stack under stable hydrogen supply conditions.

[0099] In one embodiment of this application, the step of dynamically adjusting the output power of the fuel cell according to the linkage rule further includes:

[0100] Step S420: Based on the maximum allowable current change rate of the fuel cell stack, and combined with power constraints and compensation coefficients, a multi-factor power ramp control relationship is constructed. The maximum current change rate threshold for safe operation is pre-determined through fuel cell stack performance tests to reduce problems such as voltage fluctuations and increased polarization caused by sudden current changes. Using the maximum current change rate threshold as a constraint, and integrating the set power constraints and compensation coefficients, a multi-factor power ramp control model is constructed. The multi-factor power ramp control model determines the synergistic relationship between the current change rate, temperature constraints, and altitude coefficient. When the temperature deviates from the baseline or the altitude increases, the target power range is determined based on the power constraints and compensation coefficients. Then, the rate and step size of power adjustment are limited according to the maximum current change rate threshold, making the power adjustment a smooth ramp change. This reduces the impact of sudden power changes on the fuel cell stack and ensures that the power adjustment accurately adapts to environmental factors and the safe operation requirements of the fuel cell stack.

[0101] like Figure 8 As shown, the steps for dynamically adjusting the output power of the fuel cell according to the linkage rules also include:

[0102] Step S430: Based on the target output power determined by the linkage rules, adjust the opening of the hydrogen supply valve to match the hydrogen supply corresponding to the current power requirement; calculate the target output power under the current operating conditions based on the linkage rules, and determine the hydrogen supply and demand balance corresponding to the target power by combining the stack reaction kinetics characteristics and the hydrogen-oxygen reaction molar ratio; provide real-time feedback on the current hydrogen supply through the flow detector of the hydrogen supply system, compare the deviation between the target demand and the actual supply, and dynamically adjust the opening of the hydrogen supply valve. When the target power increases, increase the valve opening to increase the hydrogen supply; when the target power decreases, decrease the valve opening to reduce hydrogen consumption, ensuring that the hydrogen supply accurately matches the current power requirement and reducing gas cross-flow caused by excessive hydrogen supply or incomplete reaction caused by insufficient hydrogen supply.

[0103] Step S440: Adjust the cooling fan speed based on the temperature difference between the fuel cell stack and the ambient temperature; collect real-time data on the fuel cell stack temperature and ambient temperature, calculate the temperature difference between the two, which reflects the degree of heat accumulation in the fuel cell stack; preset fan speed control ranges corresponding to different temperature differences; when the temperature difference exceeds the thermal management adaptation threshold, it indicates that the heat generated by the fuel cell reaction is greater than the heat dissipation efficiency, and the cooling fan speed needs to be increased to enhance the heat dissipation capacity and reduce heat accumulation that leads to fuel cell performance degradation; when the temperature difference is lower than the adaptation threshold, appropriately reduce the fan speed to save energy and prevent the temperature from being too low to affect the fuel cell reaction activity. Through dynamic adjustment of the speed, precise control of the fuel cell stack temperature is achieved, ensuring reaction stability.

[0104] Step S450: Dynamically adjust the purging time and interval based on membrane humidity detection data. The membrane humidity sensor monitors the electrolyte membrane's humidity status in real time, preseting an optimal humidity range to ensure proton conduction efficiency. When the detected membrane humidity exceeds the upper limit of the optimal range, it indicates a risk of water flooding due to excessive membrane humidity. The purging time is extended or the purging interval is shortened to accelerate the removal of excess moisture from the fuel cell stack. When the detected membrane humidity is below the lower limit of the optimal range, it indicates a drying trend in the membrane. The purging time is shortened or the purging interval is extended to reduce moisture loss. By dynamically adjusting the purging parameters, the membrane humidity is stabilized within an optimal range, ensuring proton conduction efficiency and reducing the impact of membrane wet-dryness imbalance on fuel cell stack operating efficiency and lifespan.

[0105] In this application, the temperature-power model is illustrated with an example of its establishment process. Three fuel cell stacks of the same model are selected as test samples. The parameters such as the hydrogen pressure (0.2-0.3 MPa), hydrogen purity (99.97%), and excess air coefficient (2.0-2.5) are controlled as constant values, while the ambient temperature variable is changed. The temperature adjustment range covers -40℃ (low temperature limit) to 85℃ (supercritical temperature). Thirty temperature gradients are set at 5℃ intervals, and each gradient is stably operated for 30 minutes to ensure data stability.

[0106] Real-time data were collected on the stack's output power, single-chip voltage standard deviation, stack body temperature, and reaction polarization curves under various temperature gradients. Five sets of samples were collected for each temperature gradient, and the average value was taken after removing outliers. A multiple linear regression algorithm was used to construct the model function: P=aT 2 The formula is P + bT + c, where P is the upper limit of output power corresponding to the temperature, T is the ambient temperature, and a, b, and c are the fitting coefficients. Subsequent verification was performed using 10 temperature points not involved in the fitting (e.g., -35℃, 12℃, 78℃, etc.). The error between the predicted and actual power values ​​was less than 3%, meeting the application accuracy requirements. The fitting coefficients, power safety range, adjustment priority, and other parameters for different temperature ranges are stored in the model database. When called, the corresponding range is matched with the real-time temperature, and the power constraint value is automatically output.

[0107] In addition, for the construction of the altitude power model, the above three fuel cell stacks were selected and simulated at different altitudes, such as 0m, 500m, 1000m, 1500m, 2000m, 2500m, 3000m, 3500m and 4000m, in a standard climate chamber with an ambient temperature of 25℃ and a relative humidity of 50%. The parameters such as the hydrogen pressure and gas flow rate were kept constant, and the system operated stably for 60 minutes at each altitude gradient.

[0108] Data such as atmospheric pressure, maximum safe output power of fuel cell stack, concentration polarization voltage, and open circuit voltage were collected at various altitudes. Six sets of samples were collected at each altitude. After removing outliers, the mean was taken to establish a three-dimensional dataset of altitude-atmospheric pressure-output power.

[0109] An exponential decay algorithm is used to construct the mapping relationship between altitude and compensation coefficient: Where K is the compensation coefficient corresponding to altitude, K0=1.0 is the baseline coefficient, k is the attenuation coefficient, and H is the altitude. The attenuation coefficient k was obtained by fitting 54 sets of valid data for 9 altitude gradients using SPSS software.

[0110] The model fitting error is less than 2.5%. It also incorporates an atmospheric pressure correction term; when the actual atmospheric pressure deviates from the pressure corresponding to the standard altitude by more than ±5 kPa, the k-value is automatically corrected to ensure the accuracy of the compensation coefficient. Validation was conducted at altitudes of 2200m and 3300m, two altitudes not involved in the fitting process. The power output fluctuation range after compensation coefficient correction was less than 4%, significantly better than the uncorrected version, meeting the requirements for high-altitude operation.

[0111] like Figure 9 As shown, this application also provides a fuel cell output power regulation system, which includes: a setting module 10, a quantization module 20, a setup module 30, and an adjustment module 40.

[0112] The setting module 10 is used to divide the ambient temperature into multiple temperature ranges and set power constraints for each temperature range based on a pre-established temperature-power model. The setting module 10 pre-constructs a temperature-power model by combining the reaction kinetics characteristics of the fuel cell stack, material tolerance limits, and thermal management system adaptation thresholds through temperature and power matching experiments. Simultaneously, the ambient temperature is scientifically divided into multiple ranges covering all operating conditions, such as a low-temperature operating range, a baseline operating range, a high-temperature operating range, and an over-temperature operating range, determining the temperature boundary parameters for each range. Based on the temperature-power model and temperature zoning, targeted power constraint rules are set for each range, including power maintenance standards for the baseline operating range, gradient power adjustment for the low / high-temperature operating range, and emergency control schemes for the over-temperature operating range, ensuring that the power output adapts to the impact of temperature changes on the stack reaction efficiency and safety performance.

[0113] The quantization module 20 is used to quantify the compensation coefficient between altitude and output power based on a pre-established altitude power model. Using the industry-standard benchmark operating conditions as a reference, the quantization module 20 calibrates the benchmark value of the compensation coefficient corresponding to the rated output power of the fuel cell stack under the benchmark operating conditions through experiments. Based on the physical laws of altitude increase and atmospheric pressure decrease, combined with the principles of fuel cell stack reaction kinetics, an altitude power model is constructed. By collecting atmospheric pressure, fuel cell stack output power, and polarization state data at different altitude gradients, a data fitting algorithm is used to establish a mapping relationship between altitude and the compensation coefficient, making the compensation coefficient decrease adaptively with increasing altitude. Simultaneously, real-time feedback on the fuel cell stack operating status is received, and the compensation coefficient is dynamically corrected to ensure that it accurately reflects the impact of oxygen supply capacity on power at different altitudes.

[0114] Module 30 is used to establish multi-dimensional linkage rules based on power constraints, compensation coefficients, and the operating status of the fuel cell. Module 30 constructs a multi-dimensional linkage rule system by analyzing the influence weights, interaction laws, and constraint priorities of various factors on power output, determining power adjustments under different operating condition combinations. For example, it determines the constraint priorities when high temperature and high altitude are combined, the power adaptation range when hydrogen pressure is abnormal, and the limiting conditions when polarization is intensified, ensuring that power adjustments can simultaneously respond to changes in the external environment and fluctuations in the internal operating status.

[0115] The adjustment module 40 is used to dynamically adjust the output power of the fuel cell according to the linkage rules. The adjustment module 40 uses multi-dimensional linkage rules as its core, receiving real-time data on external parameters such as ambient temperature and altitude, as well as the stack's operating status. It calculates the output power under the current operating conditions through rule matching. During the adjustment process, the module not only dynamically adjusts the power parameters but also coordinates with components such as the hydrogen supply valve, cooling fan, and purging module to simultaneously optimize the hydrogen-oxygen supply ratio, thermal management efficiency, and membrane humidity. Specifically, it adjusts the hydrogen supply opening to match power requirements, adjusts the fan speed to balance the stack temperature, and adapts the purging frequency to stabilize membrane humidity. This achieves coordinated adaptation of output power, hydrogen-oxygen supply, and hydrothermal management, ensuring stable and efficient operation of the fuel cell stack under complex conditions.

[0116] 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 of regulating the output power of a fuel cell, characterized by, The control method includes: The ambient temperature is divided into multiple temperature ranges. Based on a pre-established temperature power model, power constraints are set for each temperature range. The temperature ranges include a low-temperature operating zone, a reference operating zone, a high-temperature operating zone, and an over-temperature operating zone, with temperatures increasing sequentially. The steps for setting power constraints for each temperature range include: maintaining power output in the reference operating zone; determining the degree of deviation between the low-temperature operating zone and the high-temperature operating zone and the reference operating zone, and setting a gradient increase or decrease in power according to the degree of deviation; adjusting the output power in the over-temperature operating zone according to a preset emergency control amplitude. The temperature power model pre-stores the safe output power range and power adjustment priority data of the fuel cell stack under different temperature ranges. Based on the temperature power model, targeted power constraints are set for each temperature range to adapt the power output to the changes in response efficiency and safety risks caused by temperature changes. Based on a pre-established altitude power model, the compensation coefficient between altitude and output power is quantified. This includes: setting a standard reference operating condition, recording the rated output power of the fuel cell stack under the standard reference operating condition, and calibrating the reference coefficient using the rated output power; establishing a mapping relationship between altitude and compensation coefficient based on the reference coefficient and the attenuation law of altitude and atmospheric pressure; and correcting the compensation coefficient based on the fuel cell stack operating status, including membrane humidity and catalyst activity parameters. The step of correcting the compensation coefficient based on the fuel cell stack operating status includes: if the membrane humidity is lower than a humidity threshold, proportionally increasing the attenuation rate of the compensation coefficient; and if the catalyst activity attenuation exceeds a set threshold, decreasing the upper limit of the compensation coefficient in the high-altitude range. A multi-dimensional linkage rule is established based on the power constraint, the compensation coefficient, and the operating status of the fuel cell; According to the linkage rules, the output power of the fuel cell is dynamically adjusted; the operating state of the fuel cell includes the infeed hydrogen pressure zone state, which includes the overpressure danger zone, overpressure zone, normal operation zone, low pressure zone and low pressure danger zone with gradually decreasing pressure. According to the linkage rules, the step of dynamically adjusting the output power of the fuel cell includes: reducing the output power in the overpressure danger zone or the overpressure zone by the amount by which the hydrogen pressure exceeds the normal operating zone; reducing the upper limit of the power increase by a preset ratio in the low pressure zone or the low pressure danger zone; and dynamically adjusting the output power based on the current temperature and altitude parameters in the normal operating zone. The step of dynamically adjusting the output power of the fuel cell according to the linkage rule further includes: adjusting the opening of the hydrogen supply valve to match the hydrogen supply corresponding to the current power requirement based on the target output power determined by the linkage rule; adjusting the speed of the cooling fan according to the temperature difference between the stack body and the ambient temperature; and dynamically adjusting the purging time and interval based on the membrane humidity detection data.

2. The method of claim 1, wherein, The steps of determining the degree of deviation between the low-temperature operating zone and the high-temperature operating zone and the reference operating zone, and setting a gradient increase or decrease in power according to the degree of deviation, include: Set the reference temperature of the reference working area; Collect the real-time temperature of the low-temperature working area or the high-temperature working area, calculate the absolute difference between the real-time temperature and the reference temperature, and quantify the degree of deviation using the absolute difference. The numerical range of the deviation is divided into multiple gradient levels, and the temperature difference range corresponding to each gradient level is determined. A corresponding power adjustment range is matched for each gradient level, wherein the greater the deviation, the larger the absolute value of the corresponding power adjustment range.

3. The method of claim 1, wherein the step of modulating comprises: The step of adjusting the output power according to a preset emergency control range in the over-temperature operating zone includes: Obtain the over-temperature threshold and emergency control power range; The ambient temperature and the temperature of the fuel cell stack are collected in real time. When the ambient temperature of the fuel cell stack is greater than the over-temperature threshold, it is confirmed that the fuel cell stack has entered the over-temperature working zone. Reduce the output power to the emergency control power range.

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