Method, device and vehicle for power control of a fuel cell stack

Abstract

This application relates to a power control method, apparatus, and vehicle for a fuel cell stack, and pertains to the field of vehicle technology. The method includes: determining the gas ratio in the coolant based on the inlet water pressure information of the fuel cell stack when the coolant in the fuel cell system is insufficient; wherein the coolant is used to cool the fuel cell stack; determining the maximum allowable power of the fuel cell stack based on the gas ratio and the maximum allowable flow rate of the coolant; and performing power control on the fuel cell stack based on the maximum allowable power to ensure the safe and stable operation of the fuel cell system.

Description

Technical Field

[0001] This application relates to the field of vehicle technology, specifically to a power control method, device, and vehicle for a fuel cell stack. Background Technology

[0002] The fuel cell thermal management system is crucial for ensuring the safe and stable operation of fuel cells. Its core function is to remove the heat generated by the fuel cell stack through circulating coolant, thereby precisely controlling the inlet temperature and the temperature difference between the inlet and outlet of the fuel cell stack within the required range.

[0003] In actual operation, situations may arise where the coolant does not fill the system piping completely, such as insufficient coolant filling, leaks, or hydrogen or air from the fuel cell leaking into the coolant. Insufficient coolant will severely affect the system's heat dissipation capacity, leading to localized overheating of the fuel cell stack and ultimately damaging it. Therefore, timely and accurate diagnosis of insufficient coolant and the development of appropriate handling strategies are crucial.

[0004] Currently, the adequacy of coolant is often diagnosed by monitoring water pressure fluctuations in the thermal management system. For example, data such as thermal management system temperature, water pump speed, and thermostat opening are used to determine whether the operating load of the cooling system exceeds the predetermined load. If the operating load exceeds the predetermined load, the rate of water pressure change is used to further determine the coolant shortage status. However, existing methods mainly focus on the diagnosis of coolant insufficiency itself, lacking post-diagnosis handling strategies. Therefore, ensuring the safety of the fuel cell system after diagnosing coolant insufficiency is a critical technical problem that urgently needs to be solved. Summary of the Invention

[0005] In view of the shortcomings of the prior art, the purpose of this application is to provide a power control method, device and vehicle for a fuel cell stack, which aims to solve the problem of how to effectively ensure the safety of the fuel cell system when the coolant is insufficient.

[0006] In a first aspect, embodiments of this application provide a power control method for a fuel cell stack. The method includes: determining the gas ratio in the coolant based on the inlet water pressure information of the fuel cell stack in the fuel cell system when the coolant in the fuel cell system is insufficient; wherein the coolant is used to cool the fuel cell stack; determining the maximum allowable power of the fuel cell stack based on the gas ratio and the maximum allowable flow rate of the coolant; and performing power control on the fuel cell stack based on the maximum allowable power.

[0007] Based on the aforementioned technical means, this application determines the gas ratio in the coolant by using the inlet water pressure information of the fuel cell stack, eliminating the need for additional complex gas detection sensors. This reduces system hardware costs and structural complexity while improving the real-time performance and reliability of the detection. Furthermore, by combining the gas ratio in the coolant with the maximum allowable flow rate, the power of the fuel cell stack can be reasonably limited. This avoids overheating, performance degradation, or safety risks caused by reduced heat dissipation capacity due to gas content or insufficient flow in the coolant, ensuring safe operation of the stack even under abnormal conditions such as insufficient coolant or gas content, thereby guaranteeing the safe and stable operation of the fuel cell system.

[0008] In one possible approach, the gas ratio in the coolant is determined based on the inlet water pressure information of the fuel cell stack in the fuel cell system, including: determining the inlet water pressure fluctuation of the fuel cell stack during a target time period; wherein the target time period is a time period consisting of the current moment and a period preceding it; and determining the gas ratio in the coolant based on the inlet water pressure fluctuation and the standard inlet water pressure fluctuation of the fuel cell stack.

[0009] Based on the above technical means, this application uses the inlet water pressure fluctuation of the fuel cell stack during the target time period as a basis and compares it with the standard inlet water pressure fluctuation. This can sensitively reflect the gas-liquid mixing state in the coolant pipeline. Changes in gas content will be directly reflected in the amplitude and frequency of water pressure fluctuation. Compared with single-point water pressure value, this method has higher accuracy in identifying gas ratio and stronger anti-interference ability.

[0010] In one possible approach, determining the inlet water pressure fluctuation of the fuel cell stack during a target time period includes: determining the inlet water pressure fluctuation of the fuel cell stack during the target time period based on target information corresponding to the target time period; wherein, the target information includes: the inlet water temperature time sequence of the fuel cell stack during the target time period, the valve opening time sequence of the control valve in the fuel cell system for each flow direction during the target time period, and the speed and power time sequence of the water pump in the fuel cell system during the target time period; the water pump is used to drive the flow of coolant, and the control valve is used to control the flow direction and flow rate of coolant.

[0011] Based on the above technical means, this application jointly models the water pressure fluctuation of the fuel cell stack with multiple disturbance factors such as the inlet water temperature of the fuel cell stack, the valve opening of the control valve, and the pump speed and power. This can effectively eliminate interference caused by changes in environment, actuators, and operating conditions, avoid misjudgment of a single water pressure signal, and make the calculation results of inlet water pressure fluctuation more realistic and reliable.

[0012] In one possible approach, the gas ratio in the coolant is determined based on the inlet water pressure fluctuation and the standard inlet water pressure fluctuation of the fuel cell stack. This includes: determining the fluctuation deviation between the inlet water pressure fluctuation and the standard inlet water pressure fluctuation; determining the gas ratio corresponding to the fluctuation deviation in the mapping relationship as the gas ratio in the coolant; and the mapping relationship is used to characterize the correspondence between the fluctuation deviation between the actual inlet water pressure fluctuation and the standard inlet water pressure fluctuation of the fuel cell stack and the gas ratio in the coolant.

[0013] Based on the above technical means, this application determines the gas ratio by the fluctuation deviation between the actual inlet water pressure fluctuation and the standard inlet water pressure fluctuation of the fuel cell stack and the preset mapping relationship. This method has low computational load, fast response speed, and is easy to execute in real time in the fuel cell controller, thereby improving the real-time performance and stability of the control system.

[0014] In one possible approach, the aforementioned standard inlet water pressure fluctuation is determined based on the valve opening fluctuation of the control valve in the fuel cell system in each flow direction during the target time period and the speed fluctuation of the water pump in the fuel cell system during the target time period; the water pump is used to drive the flow of coolant, and the control valve is used to control the flow direction and flow rate of coolant.

[0015] Based on the above technical means, this application fully considers the influence of the pump driving capability, control valve flow direction and flow regulation on water pressure fluctuation in the coolant circuit. By controlling the valve opening and pump speed in real time, the standard inlet water pressure fluctuation is determined. In this way, it can adapt to different flow rates, different flow directions and different load conditions of the system, avoid the deviation caused by fixed standards, make the standard inlet water pressure fluctuation closer to the actual theoretical state of the system, and greatly improve the accuracy of gas ratio judgment.

[0016] In one possible approach, the power control method for the aforementioned fuel cell stack further includes: determining that the coolant is insufficient when the coolant meets preset conditions; wherein the preset conditions include at least: inlet water pressure fluctuation is greater than or equal to standard inlet water pressure fluctuation; speed fluctuation is less than or equal to preset speed fluctuation; and valve opening fluctuation is less than or equal to preset valve opening fluctuation.

[0017] Based on the aforementioned technical means, this application combines inlet water pressure fluctuations, pump speed fluctuations, and valve opening fluctuations as the criteria for determining insufficient coolant, effectively eliminating false triggers caused by single sensor malfunctions, operating condition disturbances, signal noise, etc., and significantly improving the accuracy and reliability of coolant shortage judgment. Specifically, under the premise that the pump speed fluctuations and valve opening fluctuations are both small (i.e., the actuator is working stably), coolant shortage is only determined when the inlet water pressure fluctuation is abnormally large, which can effectively distinguish between actuator disturbances and genuine coolant abnormalities, greatly reducing the false alarm rate. In addition, this application can quickly determine the coolant shortage state even when the system is not equipped with a pressure sensor.

[0018] In one possible approach, determining the maximum permissible power of the fuel cell stack based on the gas ratio and the maximum permissible flow rate of the coolant includes: determining the equivalent flow rate of the coolant based on the gas ratio and the maximum permissible flow rate; determining the power limiting factor of the fuel cell stack based on the equivalent flow rate and the maximum permissible flow rate; and determining the maximum permissible power based on the power limiting factor and the reference maximum permissible power of the fuel cell stack.

[0019] Based on the aforementioned technical means, this application combines the gas ratio in the coolant and the maximum allowable flow rate to determine the equivalent flow rate. This quantifies the weakening effect of gas on the coolant's heat dissipation, mass transfer, and flow, more accurately reflecting the actual heat dissipation capacity of the coolant circuit and avoiding power control deviations caused by using only theoretical flow rates. Furthermore, by correcting the reference maximum allowable power with a power limitation factor, the stack power can be precisely limited based on the actual heat dissipation capacity when the coolant contains gas and its heat dissipation capacity decreases. This avoids stack overheating and performance degradation without excessively limiting power output, achieving an optimal balance between safety and power performance.

[0020] In one possible approach, the power limiting factor of the fuel cell stack is determined based on the equivalent flow rate and the maximum allowable flow rate, including: determining the first heat dissipation capacity of the fuel cell stack at the equivalent flow rate and the second heat dissipation capacity of the fuel cell stack at the maximum allowable flow rate; and determining the power limiting factor of the fuel cell stack based on the first heat dissipation capacity and the second heat dissipation capacity.

[0021] Based on the above technical means, this application directly links the power limit coefficient with the actual heat dissipation capacity (i.e., the first heat dissipation capacity) and the theoretical maximum heat dissipation capacity (i.e., the second heat dissipation capacity), which can make the power control highly matched with the thermal safety boundary of the fuel cell stack, avoid the control deviation caused by indirect estimation based solely on flow rate, and improve the accuracy and rationality of power control.

[0022] In one possible approach, determining the power limiting factor of the fuel cell stack based on a first heat dissipation capacity and a second heat dissipation capacity includes: determining the ratio between the first heat dissipation capacity and the second heat dissipation capacity as an initial power limiting factor; determining the power limiting factor based on the initial power limiting factor and a safe power limiting factor; wherein the safe power limiting factor is used to constrain the power limiting factor to prevent the fuel cell stack from overheating or overloading.

[0023] Based on the above technical means, this application uses the heat dissipation capacity ratio as a basis and the safety power limit coefficient as a constraint, which can ensure that the power control fits the actual heat dissipation capacity and prevent the fuel cell stack from overheating and overloading, thus forming a dual safety guarantee and improving the reliability of system operation.

[0024] In one possible approach, the power control method for the aforementioned fuel cell stack further includes: determining the heat generation and heat dissipation of the fuel cell stack when the coolant in the fuel cell system is insufficient; and controlling the fuel cell system to shut down when the heat difference between the heat generation and heat dissipation is greater than or equal to a preset heat difference threshold for a duration exceeding a preset duration.

[0025] Based on the aforementioned technical means, this application uses the difference between heat generation and heat dissipation as the core judgment criterion, directly reflecting the trend of heat accumulation in the fuel cell stack. Compared with single temperature and pressure thresholds, this is closer to the physical nature of thermal runaway, making shutdown judgment more accurate and reliable. Furthermore, by judging the duration of the heat difference exceeding the threshold, it can effectively filter out transient heat deviations caused by instantaneous disturbances and signal noise, preventing accidental shutdowns under non-hazardous conditions, thus balancing system safety and operational continuity.

[0026] Secondly, embodiments of this application provide a power control device for a fuel cell stack, the device comprising: a first determining unit, a second determining unit, and a control unit.

[0027] The first determining unit is used to determine the gas ratio in the coolant based on the inlet water pressure information of the fuel cell stack in the fuel cell system when the coolant in the fuel cell system is insufficient; wherein the coolant is used to cool the fuel cell stack.

[0028] The second determining unit is used to determine the maximum allowable power of the fuel cell stack based on the gas ratio and the maximum allowable flow rate of the coolant.

[0029] The control unit is used to perform power control on the fuel cell stack based on the maximum permissible power.

[0030] In one possible embodiment, the first determining unit includes a first determining subunit and a second determining subunit. The first determining subunit is used to determine the inlet water pressure fluctuation of the fuel cell stack during a target time period; wherein the target time period is the period consisting of the current moment and a preceding time interval. The second determining subunit is used to determine the gas ratio in the coolant based on the inlet water pressure fluctuation and the standard inlet water pressure fluctuation of the fuel cell stack.

[0031] In one possible approach, the first determining subunit is specifically used to determine the inlet water pressure fluctuation of the fuel cell stack during the target time period based on the target information corresponding to the target time period. The target information includes: the inlet water temperature time sequence of the fuel cell stack during the target time period, the valve opening time sequence of the control valve in the fuel cell system for each flow direction during the target time period, and the speed and power time sequence of the water pump in the fuel cell system during the target time period. The water pump is used to drive the flow of coolant, and the control valve is used to control the flow direction and flow rate of coolant.

[0032] In one possible approach, the second determining subunit is specifically used to determine the fluctuation deviation between the inlet water pressure fluctuation and the standard inlet water pressure fluctuation; the gas ratio corresponding to the fluctuation deviation in the mapping relationship is determined as the gas ratio in the coolant; the mapping relationship is used to characterize the correspondence between the fluctuation deviation between the actual inlet water pressure fluctuation and the standard inlet water pressure fluctuation of the fuel cell stack and the gas ratio in the coolant.

[0033] In one possible approach, the first determining unit is further configured to determine the standard inlet water pressure fluctuation based on the valve opening fluctuation of the control valve in the fuel cell system in each flow direction during the target time period and the rotational speed fluctuation of the water pump in the fuel cell system during the target time period; the water pump is used to drive the flow of coolant, and the control valve is used to control the flow direction and flow rate of coolant.

[0034] In one possible embodiment, the first determining unit further includes a third determining subunit. The third determining subunit is used to determine that the coolant is insufficient if the coolant meets preset conditions; wherein the preset conditions include at least: inlet water pressure fluctuation greater than or equal to standard inlet water pressure fluctuation; speed fluctuation less than or equal to preset speed fluctuation; and valve body opening fluctuation less than or equal to preset valve body opening fluctuation.

[0035] In one possible embodiment, the second determining unit includes a fourth determining subunit, a fifth determining subunit, and a sixth determining subunit. The fourth determining subunit is used to determine the equivalent flow rate of the coolant based on the gas ratio and the maximum permissible flow rate. The fifth determining subunit is used to determine the power limiting factor of the fuel cell stack based on the equivalent flow rate and the maximum permissible flow rate. The sixth determining subunit is used to determine the maximum permissible power based on the power limiting factor and the reference maximum permissible power of the fuel cell stack.

[0036] In one possible approach, the fifth determining subunit is specifically used to determine the first heat dissipation capacity of the fuel cell stack under the equivalent flow rate and the second heat dissipation capacity of the fuel cell stack under the maximum allowable flow rate; based on the first heat dissipation capacity and the second heat dissipation capacity, the power limiting factor of the fuel cell stack is determined.

[0037] In one possible approach, the fifth determining subunit is further configured to determine the ratio between the first heat dissipation capacity and the second heat dissipation capacity as an initial power limiting factor; and to determine a power limiting factor based on the initial power limiting factor and the safe power limiting factor; wherein the safe power limiting factor is used to constrain the power limiting factor to prevent the fuel cell stack from overheating or overloading.

[0038] In one possible embodiment, the control unit includes a seventh determining subunit and a control subunit. The seventh determining subunit is used to determine the heat generation and heat dissipation of the fuel cell stack when the coolant in the fuel cell system is insufficient. The control subunit is used to control the fuel cell system to shut down if the heat difference between the heat generation and heat dissipation is greater than or equal to a preset heat difference threshold for a duration exceeding a preset time.

[0039] Thirdly, embodiments of this application provide a vehicle equipped with a power control device for the fuel cell stack described in the second aspect.

[0040] Fourthly, embodiments of this application provide an electronic device, including: a processor; and a memory for storing processor-executable instructions. The processor is configured to execute instructions to implement the power control method for a fuel cell stack according to the first aspect and any possible implementation thereof.

[0041] Fifthly, this application provides a computer-readable storage medium that, when the instructions in the computer-readable storage medium are executed by a processor of an electronic device, enables the electronic device to perform the power control method for a fuel cell stack described in the first aspect and any possible implementation thereof.

[0042] In a sixth aspect, embodiments of this application provide a computer program product, which includes computer instructions that, when executed on an electronic device, cause the electronic device to perform the power control method for a fuel cell stack described in the first aspect and any possible implementation thereof.

[0043] It should be noted that the technical effects of any of the implementation methods in aspects two through six can be found in the technical effects of the corresponding implementation methods in aspect one, and will not be repeated here.

[0044] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

[0045] To more clearly illustrate the technical solutions in the embodiments of this application or the background art, the accompanying drawings used in the embodiments of this application will be described below.

[0046] Figure 1 A schematic diagram of the power control system for a fuel cell stack provided in an embodiment of this application; Figure 2 A schematic diagram of the power control system of another fuel cell stack provided in an embodiment of this application; Figure 3A schematic flowchart illustrating a power control method for a fuel cell stack provided in an embodiment of this application; Figure 4 A schematic diagram of the structure of a power control device for a fuel cell stack provided in an embodiment of this application; Figure 5 This is a block diagram of an electronic device provided in an embodiment of this application. Detailed Implementation

[0047] To enable those skilled in the art to better understand the technical solutions of this application, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings.

[0048] It should be noted that the terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0049] In the embodiments of this application, the words "exemplary," "for example," or "for instance" are used to indicate that something is an example, illustration, or description. Any embodiment or design described as "exemplary," "for example," or "for instance" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of the words "exemplary," "for example," or "for instance" is intended to present the relevant concepts in a specific manner.

[0050] The technical solutions of the embodiments of this application will be described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments.

[0051] The power control method for fuel cell stacks provided in this application can be applied to vehicles. Vehicles can also be referred to as vehicles, mobile carriers, electric vehicles (EVs), hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), fuel cell vehicles (FCVs), autonomous vehicles, intelligent and connected vehicles (ICVs), driverless vehicles, etc.

[0052] In this application, the vehicle can be a sedan, a sport utility vehicle (SUV), a truck, an electric vehicle, a motorcycle, a tricycle, a special vehicle (such as an ambulance, fire truck, police car, etc.), a driverless taxi, an intelligent connected bus, an autonomous logistics vehicle, an electric truck, etc. Furthermore, this method is also applicable to various special-purpose vehicles, such as agricultural vehicles, mining vehicles, forestry vehicles, airport vehicles, and port vehicles. This application does not impose specific limitations in this regard.

[0053] like Figure 1 As shown in the figure, a power control system (also referred to as a fuel cell system) for a fuel cell stack provided in this application embodiment includes: a controller 101, a fuel cell thermal management system 102 (also referred to as a cooling system or heat dissipation system) and a fuel cell stack 103 deployed in a vehicle 100. The controller 101, the fuel cell thermal management system 102, and the fuel cell stack 103 are communicatively connected.

[0054] The controller 101 may include, but is not limited to, a fuel cell control unit (FCU), a vehicle control unit (VCU), and a domain control unit (DCU).

[0055] Among them, such as Figure 2 As shown, the fuel cell thermal management system 102 may include: a water pump, a three-way valve, a radiator, a radiator outlet temperature sensor, a fuel cell stack inlet temperature sensor, and a fuel cell stack outlet temperature sensor. The thermal management loop of the fuel cell thermal management system 102 is filled with coolant.

[0056] The water pump provides the power to drive the coolant to circulate throughout the thermal management circuit.

[0057] Three-way valves are used to control the direction and flow distribution of coolant. For example, during a cold start, adjusting the valve opening allows the coolant to bypass the radiator (small circulation) for rapid heating; when the temperature is too high, all the coolant flows through the radiator (large circulation) to enhance heat dissipation; they can also be used for mixed regulation to precisely control the temperature.

[0058] The radiator is used for heat exchange with the outside air, transferring coolant from the fuel cell stack 103 (e.g., ...). Figure 2 (As shown) The excess heat carried away is dissipated into the environment, thereby reducing the coolant temperature.

[0059] The radiator outlet temperature sensor is used to monitor the temperature of the coolant after it has been cooled by the radiator. This temperature signal is a key input for evaluating the heat dissipation effect of the radiator and calculating the initial temperature of the coolant entering the fuel cell stack 103.

[0060] The fuel cell stack inlet temperature sensor is used to monitor the temperature of the coolant that is about to enter the fuel cell stack 103. This temperature signal is one of the most direct feedbacks to the temperature control logic. The controller 101 can adjust the water pump, three-way valve or radiator fan to bring this temperature to the target value.

[0061] The fuel cell stack outlet temperature sensor is used to monitor the temperature of the coolant that just comes out of the fuel cell stack 103. This temperature signal directly reflects the operating temperature of the fuel cell stack 103 itself. It is the most important parameter for monitoring the thermal state of the fuel cell stack 103 and preventing overheating damage. It is also used to calculate the heat generation power of the fuel cell stack 103.

[0062] In some embodiments, during the operation of the fuel cell in the fuel cell system, the heat generated by the fuel cell stack 103 causes the coolant temperature to continuously rise from the stack inlet to the stack outlet. To maintain the temperature of the fuel cell stack 103 within the optimal operating range, the fuel cell thermal management system 102 needs to be coordinated and controlled. Specifically, the controller 101 can distribute the coolant flow by adjusting the opening of the three-way valve, control the fan speed of the radiator to change its heat dissipation intensity, and adjust the water pump speed to control the coolant circulation rate, thereby achieving precise regulation of the temperature of the fuel cell stack 103.

[0063] In some embodiments, the controller 101 can determine whether the coolant is insufficient based on the inlet water pressure fluctuation of the fuel cell stack 103 during a target time period. If the coolant is insufficient, the controller can determine the gas ratio in the coolant based on the inlet water pressure information of the fuel cell stack 103. Then, the controller can determine the maximum allowable power of the fuel cell stack 103 based on the gas ratio in the coolant and the maximum allowable flow rate of the coolant, and perform power control on the fuel cell stack 103 based on the maximum allowable power.

[0064] For ease of understanding, the power control method for fuel cell stacks provided in this application will be described in detail below with reference to the accompanying drawings.

[0065] like Figure 3 As shown in the embodiment of this application, a power control method for a fuel cell stack includes: S301. In the event of insufficient coolant in the fuel cell system, determine the gas ratio in the coolant based on the inlet water pressure information of the fuel cell stack in the fuel cell system.

[0066] The coolant is used to cool the fuel cell stack. Specifically, the controller can distribute the coolant flow by adjusting the valve openings of control valves (such as three-way valves and four-way valves) in the fuel cell thermal management system, change the heat dissipation intensity by controlling the fan speed of the radiator, and control the coolant circulation rate by adjusting the water pump speed, thereby achieving precise control of the fuel cell stack.

[0067] In some embodiments, the controller can determine the inlet water pressure fluctuation of the fuel cell stack, the speed fluctuation of the water pump, and the valve opening fluctuation of the control valve in each flow direction during a target time period. Then, based on the inlet water pressure fluctuation, speed fluctuation, and valve opening fluctuation, the controller can determine whether the coolant in the fuel cell system meets preset conditions, and if so, if the coolant meets the preset conditions, determine that the coolant is insufficient. If the coolant is determined to be insufficient, the controller can determine the gas ratio in the coolant based on the inlet water pressure fluctuation of the fuel cell stack. The specific method for determining the gas ratio in the coolant can be referred to the description in the following embodiments, and will not be repeated here.

[0068] The water pump is used to drive the flow of coolant, and the control valve is used to control the direction and flow rate of coolant.

[0069] The target time period is the period consisting of the current moment and the duration preceding it. The target time period can be determined based on the actual application. The value of the target time period should not be too large or too small. If the value is too large, it will cause system response delay and judgment lag; if the value is too small, it will make the system too sensitive and prone to misjudgment.

[0070] In this embodiment of the application, the fluctuation of inlet water pressure / speed / valve opening may include data indicators such as the standard deviation of inlet water pressure / speed / valve opening, the variance of inlet water pressure / speed / valve opening, the range of inlet water pressure / speed / valve opening, and the interquartile range of inlet water pressure / speed / valve opening, which are used to reflect the fluctuation of inlet water pressure / speed / valve opening within the target time period, and there is no limitation on them.

[0071] The preset conditions include at least the following: 1-1. The inlet water pressure fluctuation is greater than or equal to the standard inlet water pressure fluctuation.

[0072] In this embodiment, the standard inlet water pressure fluctuation is determined based on the valve opening fluctuation of the control valve in each flow direction during the target time period and the pump speed fluctuation during the target time period. The standard inlet water pressure fluctuation is directly proportional to the valve opening fluctuation and speed fluctuation; that is, the larger the valve opening fluctuation and speed fluctuation, the larger the standard inlet water pressure fluctuation, and vice versa. Specifically, the controller stores the correspondence between the valve opening fluctuation of the control valve, the speed fluctuation of the pump, and the standard inlet water pressure fluctuation. Based on this, the controller can determine the standard inlet water pressure fluctuation corresponding to the pump speed fluctuation and the valve opening fluctuation of the control valve in each flow direction during the target time period as the standard inlet water pressure fluctuation of the fuel cell stack.

[0073] For example, taking the standard inlet water pressure fluctuation as the standard deviation of the inlet water pressure, and assuming the duration of the target period is... seconds (s), data sampling period is s, Less than The number of sampling points within the target time period is In this case, the fuel cell stack during the target time period The standard deviation of the inlet water pressure within the fuel cell stack satisfies the following formulas 1 and 2. A larger standard deviation of the inlet water pressure indicates greater fluctuations in the inlet water pressure of the fuel cell stack, while a smaller standard deviation indicates lower inlet water pressure.

[0074] (Formula 1) (Formula 2) in, Indicates the fuel cell stack during the target time period Standard deviation of inlet water pressure; Indicates the target time period The number of sampling points within; Indicates the fuel cell stack during the target time period Average inlet water pressure; These represent the fuel cell stack at the first sampling point to the second sampling point. The inlet water pressure corresponding to each sampling point.

[0075] 1-2. The speed fluctuation is less than or equal to the preset speed fluctuation.

[0076] Optionally, the preset speed wave is set according to actual needs, and this application does not limit it.

[0077] For example, taking the speed fluctuation as the speed standard deviation, assuming the duration of the target period is... seconds (s), data sampling period is s, Less than The number of sampling points within the target time period is In this case, the water pump operates within the target time period. The standard deviation of the pump speed within the specified range satisfies the following formulas 3 and 4. A larger standard deviation indicates greater fluctuation in the pump speed, while a smaller standard deviation indicates less fluctuation.

[0078] (Formula 3) (Formula 4) in, Indicates the water pump during the target time period The standard deviation of rotational speed within the range; Indicates the target time period The number of sampling points within; Indicates the water pump during the target time period Average rotational speed within the range; These represent the water pump at the first sampling point to the second sampling point. The rotational speed corresponding to each sampling point.

[0079] 1-3. Valve body opening fluctuation is less than or equal to the preset valve body opening fluctuation.

[0080] Optionally, the preset speed wave is set according to actual needs, and this application does not limit it.

[0081] For example, taking the valve body opening fluctuation as the standard deviation of the valve body opening, assuming the duration of the target time period is... seconds (s), data sampling period is s, Less than The number of sampling points within the target time period is In this case, the control valve operates during the target time period. The standard deviation of the valve body opening within the control valve satisfies the following formulas 5 and 6. A larger standard deviation indicates greater fluctuation in the valve body opening, while a smaller standard deviation indicates less fluctuation.

[0082] (Formula 5) (Formula 6) in, Indicates the control valve during the target time period Standard deviation of valve body opening within the valve body; Indicates the target time period The number of sampling points within; Indicates the control valve during the target time period Average valve opening within the valve body; These represent the control valve at the first sampling point to the second sampling point. The valve opening corresponding to each sampling point.

[0083] S302. Determine the maximum allowable power of the fuel cell stack based on the gas ratio and the maximum allowable flow rate of the coolant.

[0084] In one alternative implementation, the controller can determine the equivalent flow rate of the coolant based on the gas ratio in the coolant and the maximum permissible flow rate of the coolant. Then, the controller can determine the power limiting factor of the fuel cell stack based on the equivalent flow rate and the maximum permissible flow rate of the coolant, and determine the maximum permissible power based on the power limiting factor and the reference maximum permissible power of the fuel cell stack.

[0085] In some embodiments, the controller can determine the equivalent flow rate of the coolant based on the gas ratio in the coolant and the maximum permissible flow rate of the coolant. Then, the controller can determine a first heat dissipation capacity of the fuel cell stack at the equivalent flow rate and a second heat dissipation capacity of the fuel cell stack at the maximum permissible flow rate, and determine the power limitation factor of the fuel cell stack based on the first and second heat dissipation capacities.

[0086] For example, generally speaking, a higher gas content results in less coolant and a lower coolant flow rate, which reduces the heat dissipation capacity of the fuel cell stack. Therefore, it is necessary to limit the power of the fuel cell stack. Under otherwise constant conditions, the coolant flow rate... and heat dissipation capacity They are directly proportional, approximating a quadratic relationship in one variable, that is... ,in, represents the fitting coefficient. In this case, the first heat dissipation capacity of the fuel cell stack under the equivalent flow rate satisfies the following formula 7, and the second heat dissipation capacity of the fuel cell stack under the maximum allowable flow rate satisfies the following formula 8.

[0087] (Formula 7) (Formula 8) in, Indicates primary heat dissipation capability, Indicates the second heat dissipation capability; Indicates the maximum allowed flow rate, Indicates the gas ratio in the coolant. Indicates equivalent flow rate; This represents the fitting coefficient.

[0088] For example, based on the above, the controller can determine an initial power limiting factor based on the ratio between the first heat dissipation capacity and the second heat dissipation capacity, and then determine a power limiting factor based on the initial power limiting factor and the safe power limiting factor. The controller can then determine the maximum allowable power by multiplying the power limiting factor by the reference maximum allowable power.

[0089] The safety power limit factor is used to constrain the power limit factor to prevent the fuel cell stack from overheating or overloading. The safety power limit factor ranges from 0 to 1.

[0090] For example, the power limiting factor satisfies the following formula 9, and the maximum allowable power satisfies the following formula 10.

[0091] (Formula 9) (Formula 10) in, Indicates the initial power limitation factor, Indicates primary heat dissipation capability, Indicates the second heat dissipation capacity, Indicates the safe power limit factor; Indicates the maximum allowable power, This indicates the maximum permissible power at the reference level.

[0092] S303. Power control of the fuel cell stack is performed based on the maximum permissible power.

[0093] In some embodiments, the controller can acquire the output power of the fuel cell stack in real time. If the output power of the fuel cell stack is greater than the maximum allowable power, the controller can control the output power of the fuel cell stack to be below the maximum allowable power. If the output power of the fuel cell stack is less than or equal to the maximum allowable power, the controller can control the fuel cell stack to operate at the current output power.

[0094] Based on the above technical solution, this application determines the gas ratio in the coolant by using the inlet water pressure information of the fuel cell stack, eliminating the need for additional complex gas detection sensors. This reduces system hardware costs and structural complexity while improving the real-time performance and reliability of the detection. Furthermore, by combining the gas ratio in the coolant with the maximum allowable flow rate, the power of the fuel cell stack can be reasonably limited. This prevents overheating, performance degradation, or safety risks caused by insufficient heat dissipation due to gas in the coolant or insufficient flow, ensuring safe operation of the stack even under abnormal conditions such as insufficient coolant or gas content, thereby guaranteeing the safe and stable operation of the fuel cell system.

[0095] In one alternative implementation, when the coolant in the fuel cell system is insufficient, the controller can determine the inlet water pressure fluctuation of the fuel cell stack during a target period, and then determine the gas ratio in the coolant based on the inlet water pressure fluctuation and the standard inlet water pressure fluctuation of the fuel cell stack.

[0096] In some embodiments, the controller can determine the inlet water pressure fluctuation of the fuel cell stack during the target time period based on the target information corresponding to the fuel cell system during the target time period. Furthermore, the controller can determine the standard inlet water pressure fluctuation of the fuel cell stack based on the valve opening fluctuation of the control valve in each flow direction and the pump speed fluctuation during the target time period. Based on this, the controller can determine the fluctuation deviation between the inlet water pressure fluctuation and the standard inlet water pressure fluctuation, and then determine the gas ratio corresponding to the fluctuation deviation in the mapping relationship as the gas ratio in the coolant.

[0097] The mapping relationship is used to characterize the fluctuation deviation between the actual inlet water pressure fluctuation and the standard inlet water pressure fluctuation of the fuel cell stack, and the correspondence between the gas ratio in the coolant.

[0098] The target information may include: the inlet water temperature sequence of the fuel cell stack during the target time period, the valve opening sequence of the control valve in each flow direction during the target time period, and the speed and power sequence of the water pump during the target time period. The water pump is used to drive the flow of coolant, and the control valve is used to control the flow direction and flow rate of the coolant.

[0099] Optionally, the fluctuations in valve body opening and rotational speed can be referenced to the inlet water pressure fluctuations mentioned above. For example, the fluctuations in valve body opening can include the standard deviation of valve body opening, the variance of valve body opening, the range of valve body opening, and the interquartile range of valve body opening, etc., to reflect the fluctuations in the valve body opening of the control valve within the target time period. Other fluctuations are similar and will not be elaborated here.

[0100] In one example, for each sampling sub-time within the target time period, the controller can acquire the inlet water temperature of the fuel cell stack, the valve opening degree of the control valve in each flow direction, and the rotational speed and power of the water pump at that sampling sub-time using a data acquisition device. Then, the controller can determine the inlet water pressure of the fuel cell stack at that sampling sub-time using the acquired information and the fitted relationship (refer to Formula 11 below).

[0101] Based on the above, the controller can determine the inlet water pressure of the fuel cell stack at each sampling sub-time during the target period using the aforementioned method. Furthermore, based on the inlet water pressure of the fuel cell stack at each sampling sub-time during the target period and the average inlet water pressure of the fuel cell stack during the target period, the controller can determine the inlet water pressure fluctuation of the fuel cell stack during the target period. The specific calculation method for the inlet water pressure fluctuation can be found in the description of Formula 1 above, and will not be elaborated upon here.

[0102]

[0103] (Formula 11) in, This indicates the inlet water pressure of the fuel cell stack at the sampling sub-time. This indicates the inlet water temperature of the fuel cell stack. This indicates the pump speed during the sampling sub-time. This indicates the valve body opening degree of the control valve at the sampling sub-time. This indicates the power of the water pump during the sampling sub-time; , , , , , , , , and This represents the fitting coefficient.

[0104] In this embodiment of the application, the above fitting relationship (i.e. the above formula (11)) is obtained by collecting test data under different working conditions and by fitting the test data through a polynomial.

[0105] In another example, the controller incorporates a neural network model for calculating the inlet water pressure of the fuel cell stack. The controller can input the inlet water temperature of the fuel cell stack at each sampling time, the valve opening degree of the control valve in each flow direction at each sampling time, and the pump speed and power at each sampling time into the neural network model to obtain the inlet water pressure of the fuel cell stack at each sampling time. Subsequently, the controller can determine the inlet water pressure of the fuel cell stack at each sampling time within a target time period using the above method, thus identifying the inlet water pressure fluctuations of the fuel cell stack within the target time period.

[0106] For example, the standard deviation of the inlet water pressure of the fuel cell stack within a target time is determined in accordance with the above method. Then, the controller can determine the standard deviation of the inlet water pressure of the fuel cell stack. Standard deviation of standard inlet water pressure The standard deviation between them is And the deviation from the standard deviation in the mapping relationship is... Corresponding gas ratio This refers to the proportion of gas in the coolant.

[0107] Based on the above technical solution, this application uses the inlet water pressure fluctuation of the fuel cell stack during the target time period as a basis and compares it with the standard inlet water pressure fluctuation. This can sensitively reflect the gas-liquid mixing state in the coolant pipeline. Changes in gas content are directly reflected in the amplitude and frequency of water pressure fluctuations. Compared with single-point water pressure values, this method has higher accuracy in identifying gas proportions and stronger anti-interference capabilities. In addition, this application jointly models the water pressure fluctuation of the fuel cell stack with multiple disturbance factors such as the inlet water temperature of the fuel cell stack, the valve opening of the control valve, and the pump speed and power. This can effectively eliminate interference caused by changes in the environment, actuators, and operating conditions, avoid misjudgment of a single water pressure signal, and make the calculation results of the inlet water pressure fluctuation more realistic and reliable.

[0108] In one alternative implementation, if the coolant in the fuel cell system is determined to be insufficient, the controller can determine the heat generation and heat dissipation of the fuel cell stack. Then, if the heat difference between the heat generation and heat dissipation of the fuel cell stack is greater than or equal to a preset heat difference threshold for a duration exceeding a preset duration, the controller can shut down the fuel cell system.

[0109] The preset duration is determined based on the power of the fuel cell stack (e.g., by looking up a table or fitting a formula). The power of the fuel cell stack is inversely proportional to the preset duration; that is, the greater the power of the fuel cell stack, the shorter the preset duration, and vice versa. For example, the preset duration satisfies the following formula 12.

[0110] (Formula 12) in, Indicates preset duration, Indicates the power of the fuel cell stack, This represents the fitting coefficient.

[0111] Optionally, the preset heat difference threshold can be set according to actual needs, and this application does not limit it.

[0112] In some embodiments, the controller can determine the heat generation of the fuel cell stack based on the current, operating power, and number of individual fuel cells in the fuel cell system. Simultaneously, the controller can determine the heat dissipation of the fuel cell stack based on the inlet and outlet water temperatures, the actual flow rate of the coolant, and the thermophysical parameters of the coolant. Then, the controller can calculate the heat difference between the heat generation and heat dissipation of the fuel cell stack, and if the heat difference is greater than or equal to a preset heat difference threshold for a duration exceeding a preset time, the controller will shut down the fuel cell system.

[0113] The thermophysical parameters of the coolant may include specific heat capacity and density.

[0114] For example, the heat generation of the fuel cell stack satisfies the following formula 13, and the heat dissipation of the fuel cell stack satisfies the following formulas 14-15.

[0115] (Formula 13) (Formula 14) (Formula 15) in, Indicates heat output, Indicates heat dissipation; Indicates the enthalpy change of hydrogen, Indicates the number of fuel cell cells, Indicates the current of the fuel cell, Indicates the power of the fuel cell, Denotes Faraday's constant; Indicates the outlet temperature of the fuel cell stack, Indicates the inlet temperature of the fuel cell stack, Indicates the inlet and outlet temperature difference of the fuel cell stack. Indicates the specific heat capacity of the coolant, Indicates coolant density, This indicates the actual flow rate of the coolant.

[0116] Based on the above technical solution, this application uses the difference between heat generation and heat dissipation as the core judgment criterion, directly reflecting the trend of heat accumulation in the fuel cell stack. Compared with single temperature and pressure thresholds, this is closer to the physical nature of thermal runaway, and the shutdown judgment is more accurate and reliable. In addition, by judging the duration of the heat difference exceeding the threshold, it can effectively filter out the short-term heat deviation caused by instantaneous disturbances and signal noise, prevent accidental shutdowns under non-hazardous operating conditions, and balance system safety and operational continuity.

[0117] like Figure 4 As shown in the embodiment of this application, a power control device for a fuel cell stack is provided. The device includes a first determining unit 401, a second determining unit 402, and a control unit 403.

[0118] The first determining unit 401 is used to determine the gas ratio in the coolant based on the inlet water pressure information of the fuel cell stack in the fuel cell system when the coolant in the fuel cell system is insufficient; wherein the coolant is used to cool the fuel cell stack.

[0119] The second determining unit 402 is used to determine the maximum allowable power of the fuel cell stack based on the gas ratio and the maximum allowable flow rate of the coolant.

[0120] Control unit 403 is used to perform power control on fuel cell stack based on maximum permissible power.

[0121] In one possible embodiment, the first determining unit 401 includes a first determining subunit and a second determining subunit. The first determining subunit is used to determine the inlet water pressure fluctuation of the fuel cell stack during a target time period; wherein the target time period is the period consisting of the current moment and a preceding time interval. The second determining subunit is used to determine the gas ratio in the coolant based on the inlet water pressure fluctuation and the standard inlet water pressure fluctuation of the fuel cell stack.

[0122] In one possible approach, the first determining subunit is specifically used to determine the inlet water pressure fluctuation of the fuel cell stack during the target time period based on the target information corresponding to the target time period. The target information includes: the inlet water temperature time sequence of the fuel cell stack during the target time period, the valve opening time sequence of the control valve in the fuel cell system for each flow direction during the target time period, and the speed and power time sequence of the water pump in the fuel cell system during the target time period. The water pump is used to drive the flow of coolant, and the control valve is used to control the flow direction and flow rate of coolant.

[0123] In one possible approach, the second determining subunit is specifically used to determine the fluctuation deviation between the inlet water pressure fluctuation and the standard inlet water pressure fluctuation; the gas ratio corresponding to the fluctuation deviation in the mapping relationship is determined as the gas ratio in the coolant; the mapping relationship is used to characterize the correspondence between the fluctuation deviation between the actual inlet water pressure fluctuation and the standard inlet water pressure fluctuation of the fuel cell stack and the gas ratio in the coolant.

[0124] In one possible approach, the first determining unit 401 is further configured to determine the standard inlet water pressure fluctuation based on the valve opening fluctuation of the control valve in the fuel cell system in each flow direction during the target time period and the rotational speed fluctuation of the water pump in the fuel cell system during the target time period; the water pump is used to drive the flow of coolant, and the control valve is used to control the flow direction and flow rate of coolant.

[0125] In one possible embodiment, the first determining unit 401 further includes a third determining subunit. The third determining subunit is used to determine that the coolant is insufficient if the coolant meets preset conditions; wherein the preset conditions include at least: inlet water pressure fluctuation greater than or equal to standard inlet water pressure fluctuation; speed fluctuation less than or equal to preset speed fluctuation; and valve opening fluctuation less than or equal to preset valve opening fluctuation.

[0126] In one possible embodiment, the second determining unit 402 includes a fourth determining subunit, a fifth determining subunit, and a sixth determining subunit. The fourth determining subunit is used to determine the equivalent flow rate of the coolant based on the gas ratio and the maximum permissible flow rate. The fifth determining subunit is used to determine the power limiting factor of the fuel cell stack based on the equivalent flow rate and the maximum permissible flow rate. The sixth determining subunit is used to determine the maximum permissible power based on the power limiting factor and the reference maximum permissible power of the fuel cell stack.

[0127] In one possible approach, the fifth determining subunit is specifically used to determine the first heat dissipation capacity of the fuel cell stack under the equivalent flow rate and the second heat dissipation capacity of the fuel cell stack under the maximum allowable flow rate; based on the first heat dissipation capacity and the second heat dissipation capacity, the power limiting factor of the fuel cell stack is determined.

[0128] In one possible approach, the fifth determining subunit is further configured to determine the ratio between the first heat dissipation capacity and the second heat dissipation capacity as an initial power limiting factor; and to determine a power limiting factor based on the initial power limiting factor and the safe power limiting factor; wherein the safe power limiting factor is used to constrain the power limiting factor to prevent the fuel cell stack from overheating or overloading.

[0129] In one possible embodiment, the control unit 403 includes a seventh determining subunit and a control subunit. The seventh determining subunit is used to determine the heat generation and heat dissipation of the fuel cell stack when the coolant in the fuel cell system is insufficient. The control subunit is used to control the fuel cell system to shut down if the heat difference between the heat generation and heat dissipation is greater than or equal to a preset heat difference threshold for a duration exceeding a preset duration.

[0130] like Figure 5 As shown in the embodiments of this application, an electronic device includes, but is not limited to, a processor 501 and a memory 502.

[0131] The memory 502 described above is used to store the executable instructions of the processor 501. It is understood that the processor 501 is configured to execute instructions to implement the power control method of the fuel cell stack in the above embodiment.

[0132] It should be noted that those skilled in the art will understand that Figure 5 The electronic device structure shown does not constitute a limitation on the electronic device; the electronic device may include, but is not limited to, other electronic devices. Figure 5 This may indicate more or fewer components, or combinations of certain components, or different component arrangements.

[0133] Processor 501 is the control center of the electronic device. It connects various parts of the electronic device via various interfaces and lines. By running or executing software programs and / or modules stored in memory 502, and by calling data stored in memory 502, it performs various functions and processes data, thereby providing overall monitoring of the electronic device. Processor 501 may include one or more processing units. Optionally, processor 501 may integrate an application processor and a modem processor. The application processor mainly handles the operating system, user interface, and applications, while the modem processor mainly handles wireless communication. It is understood that the modem processor may not be integrated into processor 501.

[0134] The memory 502 can be used to store software programs and various data. The memory 502 may primarily include a program storage area and a data storage area. The program storage area may store the operating system, application programs required by at least one functional module (such as a determination unit, processing unit, etc.), etc. Furthermore, the memory 502 may include high-speed random access memory and may also include non-volatile memory. For example, non-volatile memory may include at least one disk storage device, flash memory device, or other non-volatile solid-state storage device.

[0135] In an exemplary embodiment, a computer-readable storage medium including instructions is also provided, such as a memory 502 including instructions, which can be executed by a processor 501 of an electronic device to implement the methods in the above embodiments.

[0136] Optionally, the computer-readable storage medium may be a non-transitory computer-readable storage medium, such as a read-only memory (ROM), random access memory (RAM), CD-ROM, magnetic tape, floppy disk, and optical data storage device.

[0137] In an exemplary embodiment, this application also provides a computer program product including one or more instructions, which can be executed by a processor 501 of an electronic device to perform the methods described above.

[0138] It should be noted that when one or more instructions in the computer-readable storage medium or computer program product are executed by the processor of an electronic device, they implement the various processes of the above method embodiments and achieve the same technical effect as the above method. To avoid repetition, they will not be described again here.

[0139] Through the above description of the embodiments, those skilled in the art can clearly understand that, for the sake of convenience and brevity, only the division of the above functional modules is used as an example. In actual applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above.

[0140] In the several embodiments provided in this application, it should be understood that the disclosed apparatus and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of modules or units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another apparatus, or some features may be ignored or not executed. Furthermore, the mutual coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0141] The units described as separate components may or may not be physically separate. A component shown as a unit can be one or more physical units; that is, it can be located in one place or distributed in multiple different locations. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0142] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0143] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a readable storage medium. Based on this understanding, the technical solutions of the embodiments of this application, essentially, or the parts that contribute to the prior art, or all or part of the technical solutions, can be embodied in the form of a software product. This software product is stored in a storage medium and includes several instructions to cause a device (which may be a microcontroller, chip, etc.) or processor to execute all or part of the steps of the methods of the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, ROM, RAM, magnetic disks, or optical disks.

[0144] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any changes or substitutions within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A power control method for a fuel cell stack, characterized in that, The power control method for the fuel cell stack includes: In the event of insufficient coolant in the fuel cell system, the gas ratio in the coolant is determined based on the inlet water pressure information of the fuel cell stack in the fuel cell system; wherein, the coolant is used to cool the fuel cell stack. The maximum allowable power of the fuel cell stack is determined based on the gas ratio and the maximum allowable flow rate of the coolant. Based on the maximum allowable power, power control is performed on the fuel cell stack.

2. The power control method for a fuel cell stack according to claim 1, characterized in that, Determining the gas ratio in the coolant based on the inlet water pressure information of the fuel cell stack in the fuel cell system includes: Determine the inlet water pressure fluctuation of the fuel cell stack during a target time period; wherein, the target time period is the period consisting of the current moment and a preceding time period; The gas ratio in the coolant is determined based on the inlet water pressure fluctuation and the standard inlet water pressure fluctuation of the fuel cell stack.

3. The power control method for a fuel cell stack according to claim 2, characterized in that, Determining the inlet water pressure fluctuation of the fuel cell stack during the target time period includes: Based on the target information corresponding to the target time period, the inlet water pressure fluctuation of the fuel cell stack during the target time period is determined; The target information includes: the inlet water temperature sequence of the fuel cell stack during the target time period, the valve opening sequence of the control valve in the fuel cell system for each flow direction during the target time period, and the rotational speed and power sequence of the water pump in the fuel cell system during the target time period; the water pump is used to drive the flow of the coolant, and the control valve is used to control the flow direction and flow rate of the coolant.

4. The power control method for a fuel cell stack according to claim 2, characterized in that, Determining the gas ratio in the coolant based on the inlet water pressure fluctuation and the standard inlet water pressure fluctuation of the fuel cell stack includes: Determine the fluctuation deviation between the inlet water pressure fluctuation and the standard inlet water pressure fluctuation; The proportion of gas corresponding to the fluctuation deviation in the mapping relationship is determined as the proportion of gas in the coolant; the mapping relationship is used to characterize the correspondence between the fluctuation deviation between the actual inlet water pressure fluctuation and the standard inlet water pressure fluctuation of the fuel cell stack and the proportion of gas in the coolant.

5. The power control method for a fuel cell stack according to any one of claims 2-4, characterized in that, The standard inlet water pressure fluctuation is determined based on the valve opening fluctuation of the control valve in the fuel cell system in each flow direction during the target time period and the rotational speed fluctuation of the water pump in the fuel cell system during the target time period; the water pump is used to drive the flow of the coolant, and the control valve is used to control the flow direction and flow rate of the coolant.

6. The power control method for a fuel cell stack according to claim 5, characterized in that, The power control method for the fuel cell stack further includes: If the coolant meets the preset conditions, it is determined that the coolant is insufficient; The preset conditions include at least the following: the inlet water pressure fluctuation is greater than or equal to the standard inlet water pressure fluctuation; The rotational speed fluctuation is less than or equal to the preset rotational speed fluctuation; The valve body opening fluctuation is less than or equal to the preset valve body opening fluctuation.

7. The power control method for a fuel cell stack according to any one of claims 1-4, characterized in that, Determining the maximum allowable power of the fuel cell stack based on the gas ratio and the maximum allowable flow rate of the coolant includes: The equivalent flow rate of the coolant is determined based on the gas ratio and the maximum allowable flow rate. Based on the equivalent flow rate and the maximum allowable flow rate, the power limitation factor of the fuel cell stack is determined; The maximum allowable power is determined based on the power limitation factor and the reference maximum allowable power of the fuel cell stack.

8. The power control method for a fuel cell stack according to claim 7, characterized in that, Determining the power limitation factor of the fuel cell stack based on the equivalent flow rate and the maximum allowable flow rate includes: Determine the first heat dissipation capacity of the fuel cell stack under the equivalent flow rate, and the second heat dissipation capacity of the fuel cell stack under the maximum allowable flow rate; Based on the first heat dissipation capacity and the second heat dissipation capacity, the power limitation factor of the fuel cell stack is determined.

9. The power control method for a fuel cell stack according to claim 8, characterized in that, Determining the power limitation factor of the fuel cell stack based on the first heat dissipation capacity and the second heat dissipation capacity includes: The ratio between the first heat dissipation capacity and the second heat dissipation capacity is determined as the initial power limiting factor; Based on the initial power limiting factor and the safe power limiting factor, the power limiting factor is determined; wherein the safe power limiting factor is used to constrain the power limiting factor to prevent the fuel cell stack from overheating or overloading.

10. The power control method for a fuel cell stack according to any one of claims 1-4, characterized in that, The power control method for the fuel cell stack further includes: In the event of insufficient coolant in the fuel cell system, determine the heat generation and heat dissipation of the fuel cell stack. If the heat difference between the heat generated and the heat dissipation is greater than or equal to a preset heat difference threshold for a duration exceeding a preset duration, the fuel cell system is controlled to shut down.

11. A power control device for a fuel cell stack, characterized in that, The power control device for the fuel cell stack includes: The first determining unit is configured to determine the gas ratio in the coolant based on the inlet water pressure information of the fuel cell stack in the fuel cell system when the coolant in the fuel cell system is insufficient; wherein the coolant is used to cool the fuel cell stack. The second determining unit is used to determine the maximum allowable power of the fuel cell stack based on the gas ratio and the maximum allowable flow rate of the coolant; A control unit is used to perform power control on the fuel cell stack based on the maximum allowable power.

12. A vehicle, characterized in that, The vehicle is equipped with a power control device for the fuel cell stack as described in claim 11.

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