Fuel cell power limit calculation method and system and vehicle

Abstract

The invention belongs to the technical field of fuel cell thermal management, and particularly relates to a fuel cell power limit calculation method and system and a vehicle, and the method comprises the steps that the heat dissipation capacity of a current radiator is calculated, and the heat dissipation capacity is determined based on different vehicle speeds, fan rotating speeds and the actual heat dissipation capacity under the flow of cooling liquid flowing through the radiator in the actual operation process of the vehicle; preliminarily determining a power limit value at the current vehicle speed according to the heat dissipation capability and a polarization curve of the fuel cell; and adjusting the power limit value according to the actual temperature of the fuel cell. According to the method, the power limit value can be actively calculated in advance, and the power limit value is dynamically adjusted according to the actual heat dissipation capability and the environmental condition, so that the safe and efficient operation of the fuel cell is ensured.

Description

Technical Field

[0001] The present invention belongs to the technical field of fuel cell thermal management, and particularly relates to a fuel cell power limit calculation method, system and vehicle. Background Art

[0002] With the continuous development of fuel cell technology, its application in fields such as automobiles is becoming increasingly widespread. However, during the actual operation of a fuel cell, its performance is affected by various factors, among which thermal management is a crucial link. A large amount of heat is generated during the power generation process of a fuel cell. If this heat cannot be effectively dissipated, it will cause the temperature of the fuel cell to rise, thereby affecting its performance and lifespan.

[0003] In existing fuel cell thermal management systems, the control of fuel cell power limit mainly adopts a passive method. For example, the power limit value of the fuel cell is directly obtained by looking up a table based on the coolant temperature value at the outlet of the stack. Although this method can avoid fuel cell overheating to a certain extent, it has obvious hysteresis. When the fuel cell power increases, if the generated heat exceeds the heat dissipation capacity of the heat dissipation system, the temperature will rise. By this time, it is already too late to adjust the power limit value according to the temperature value, and the fuel cell may have experienced unnecessary thermal stress, causing damage to its lifespan.

[0004] Another method is to adjust the power limit value according to the ambient temperature value on the intake side of the radiator. Although this method takes into account the influence of ambient temperature on the heat dissipation capacity and realizes dynamic adjustment of power limit to a certain extent, it still decides whether to increase the power limit value based on the change and duration of ambient temperature after the power increases. This method also has hysteresis and cannot actively calculate and set an appropriate power limit value in advance to prevent overheating.

[0005] In addition, during the actual operation of a fuel cell, various unexpected situations may occur, such as extrusion of the cooling pipeline, damage to the radiator, insufficient coolant, etc. These situations will all cause a sudden decrease in the heat dissipation capacity. If the maximum power of the fuel cell is not limited at this time, the fuel cell is very likely to overheat in a short time, causing irreversible damage to it.

[0006] In summary, the existing fuel cell power limit control methods mainly have the following problems: First, the control strategy is passive and cannot actively calculate and set the power limit value in advance; second, there is hysteresis and it is impossible to effectively prevent overheating at the initial stage of heat generation; third, there is a lack of response ability to unexpected situations and it is impossible to quickly adjust the power limit value to protect the fuel cell when the heat dissipation capacity suddenly decreases.

[0007] Therefore, it is necessary to develop a new fuel cell power limit calculation method, system and vehicle. Summary of the Invention

[0008] The object of the present invention is to provide a fuel cell power limit calculation method, system and vehicle, which can actively calculate the power limit value in advance and dynamically adjust the power limit value according to the actual heat dissipation capacity and environmental conditions.

[0009] In the first aspect, a fuel cell power limit calculation method according to the present invention includes the following steps:

[0010] Calculate the heat dissipation capacity of the current radiator, which is determined based on the actual heat dissipation amount under different vehicle speeds, fan speeds, and coolant flow rates through the radiator during the actual operation of the vehicle;

[0011] Based on the heat dissipation capacity and the polarization curve of the fuel cell, preliminarily determine the power limit value at the current vehicle speed;

[0012] Adjust the power limit value according to the actual temperature of the fuel cell.

[0013] Optionally, the calculating the heat dissipation capacity of the current radiator includes:

[0014] Record the actual heat dissipation amount under different vehicle speeds, fan speeds, and coolant flow rates through the radiator during the actual operation of the vehicle;

[0015] According to the corresponding relationship between the vehicle speed, fan speed, coolant flow rate through the radiator and the heat dissipation capacity, fit to obtain the relationship between the heat dissipation capacity and the vehicle speed, fan speed, and coolant flow rate through the radiator;

[0016] Substitute the maximum fan speed and the maximum coolant flow rate through the radiator into the relationship to obtain the maximum heat dissipation capacity at the current vehicle speed. By recording the actual heat dissipation amount under different operating conditions during the actual operation of the vehicle, a rich data basis is provided for subsequent analysis, making the calculation of the heat dissipation capacity more in line with the actual operating conditions and improving the accuracy of the calculation results. Fitting the relationship according to the corresponding relationship between the vehicle speed, fan speed, coolant flow rate and heat dissipation capacity realizes the quantitative description of the heat dissipation capacity, can quickly calculate the heat dissipation capacity through simple parameter input, improves the calculation efficiency, and is convenient for evaluating the heat dissipation capacity under different operating conditions. Substituting the maximum fan speed and the maximum coolant flow rate through the radiator into the relationship to obtain the maximum heat dissipation capacity at the current vehicle speed clarifies the heat dissipation limit of the radiator under extreme operating conditions and provides a key basis for subsequent determination of the power limit value.

[0017] Optionally, the preliminarily determining the current power limit value includes:

[0018] During the actual power generation process of the fuel cell, the one-to-one correspondence between the heat generation and the power is determined according to the polarization curve. When the heat generation is equal to the maximum heat dissipation capacity at the current vehicle speed, the power corresponding to the heat generation at this time is the power limit value. This ensures that the heat generated by the fuel cell during operation can be dissipated in time, avoiding affecting the performance and lifespan due to overheating.

[0019] Optionally, in the step of preliminarily determining the power limit value at the current speed, it further includes:

[0020] Real-time monitor the change in the health state of the fuel cell, and correct the power limit value corresponding to the heat generation according to the health state of the fuel cell. As the fuel cell decays and the health state deteriorates, at the same heat generation, the power of the fuel cell will become smaller. Therefore, it is necessary to correct the power limit value corresponding to the heat generation according to the health state of the fuel cell to ensure that the power limit value is more accurate, improving the usage efficiency and reliability of the fuel cell throughout its lifecycle.

[0021] Optionally, adjusting the power limit value according to the actual temperature of the fuel cell includes:

[0022] When the radiator reaches the maximum heat dissipation capacity, obtain the actual outlet temperature, target outlet temperature, actual inlet temperature, and target inlet temperature of the fuel cell, and set the outlet temperature error threshold and inlet temperature error threshold;

[0023] If the sum of the target outlet temperature and the outlet temperature error threshold is less than the target outlet temperature, or the sum of the target inlet temperature and the inlet temperature error threshold is less than the target inlet temperature, then adjust the power limit value according to the PID feedback control; and control the output power of the fuel cell according to the adjusted power limit value. When the temperature does not meet the requirements, adjust the power limit value according to the PID feedback control, and control the output power of the fuel cell according to the adjusted power limit value, achieving precise control of the fuel cell power, being able to quickly respond to temperature changes, and keeping the fuel cell in the best working state all the time.

[0024] Optionally, when the radiator does not reach the maximum heat dissipation capacity, but the actual power of the fuel cell is equal to the power limit value, re-determine the relationship between the heat dissipation capacity, vehicle speed, fan speed, and coolant flow rate through the radiator, and use the power value corresponding to the maximum heat generation calculated after re-determining the relationship as the power limit value at the current vehicle speed. This ensures that the power limit value is always accurately calculated based on the current heat dissipation capacity, improving the accuracy of power limit.

[0025] Optionally, adjusting the power limit value according to the actual temperature of the fuel cell further includes:

[0026] When the current radiator reaches its maximum heat dissipation capacity, if the absolute difference between the target outlet temperature and the actual outlet temperature is less than or equal to the outlet temperature error threshold, and the absolute difference between the target inlet temperature and the actual inlet temperature is less than or equal to the inlet temperature error threshold, then the actual power of the current fuel cell is taken as the power limit value at the current vehicle speed;

[0027] When the radiator has not reached its maximum heat dissipation capacity and the actual power of the fuel cell is less than the power limit value, the current power limit value is maintained unchanged. This avoids unnecessary adjustments, simplifies the control logic, and improves the stability of the system.

[0028] Optionally, the adjustment of the power limit value according to PID feedback control includes:

[0029] Taking the heat dissipation of the current radiator as the maximum heat dissipation capacity of the radiator at the current vehicle speed to initially obtain the power limit value;

[0030] Taking the larger value of the difference between the target outlet temperature and the actual outlet temperature and the difference between the target inlet temperature and the actual inlet temperature as the error value, and inputting the error value into the PID feedback control to obtain the corrected power;

[0031] Calculating the final power limit value at the current vehicle speed based on the corrected power and the initially obtained power limit value. Calculating the final power limit value at the current vehicle speed based on the corrected power and the initially obtained power limit value comprehensively considers the influence of the initial power limit value and the temperature deviation, making the power limit value more accurate and better able to meet the operating requirements of the fuel cell.

[0032] In a second aspect, a fuel cell power limit calculation system according to the present invention includes a memory and a controller. The memory stores a computer-readable program. When the computer-readable program is called by the controller, it can execute the steps of the fuel cell power limit calculation method according to the present invention.

[0033] In a third aspect, a vehicle according to the present invention employs the fuel cell power limit calculation system according to the present invention.

[0034] Advantages of the present invention:

[0035] (1) By recording the data of the fuel cell operation, the present invention uses an advanced fitting algorithm to accurately obtain the complex relationship between the current heat dissipation of the radiator and the rotational speed, flow rate, and vehicle speed of the fan. Based on this relationship, the maximum heat dissipation capacity of the heat dissipation system can be calculated in advance, and then a reasonable current power limit value can be determined. This method realizes the transformation from passive response to active prevention, enabling the system to set a suitable power limit value according to the heat dissipation capacity at the initial stage of heat generation, effectively preventing the occurrence of over-temperature conditions, and protecting the fuel cell from heat stress damage.

[0036] (2) The present invention not only calculates the power limit value in advance, but also makes real-time corrections according to the actual operating temperature change of the fuel cell. With the continuous accumulation of operating data, the system will automatically update the calculation relationship of the heat dissipation amount multiple times to ensure the accuracy of the power limit value. Through the real-time correction mechanism of the present invention, the system can dynamically adapt to the changes in the operating state of the fuel cell, ensure that the calculated power limit value is always within the safe range, and avoid the over-temperature risk caused by hysteresis.

[0037] (3) The present invention comprehensively determines the power limit value by directly calculating the heat dissipation capacity of the heat dissipation system in the current scenario and combining with the health state of the fuel cell. When the fuel cell system reaches the maximum heat dissipation capacity, the system can further fine-tune the power limit value according to the temperature change. This method has high flexibility and adaptability, and can cover various operating scenarios, including normal conditions and unexpected situations. When the heat dissipation capacity suddenly drops, the system can quickly respond and adjust the power limit value in time to ensure that the fuel cell will not suffer irreversible damage due to over-temperature.

[0038] In summary, through the technical means of active calculation, real-time correction and comprehensive coverage, the present invention provides a strong guarantee for the safe and efficient operation of the fuel cell. Description of the Drawings

[0039] Figure 1 is a flowchart of the fuel cell power limit calculation method described in the embodiments of the present application;

[0040] Figure 2 is an architecture diagram of the fuel cell thermal management system in the embodiments of the present application;

[0041] Figure 3 is a principle block diagram of the fuel cell power limit calculation system in the embodiments of the present application;

[0042] In the figure: 1, water pump; 2, inlet temperature sensor of the stack; 3, stack; 4, outlet temperature sensor of the stack; 5, three-way valve; 6, radiator; 7, fan; 8, outlet temperature sensor of the radiator. Detailed Embodiments

[0043] The following will describe the embodiments of the present invention with reference to the accompanying drawings and preferred embodiments. Those skilled in the art can understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be understood that the preferred embodiments are only for illustrating the present invention, rather than for limiting the protection scope of the present invention.

[0044] AsFigure 1 As shown, in an embodiment of the present application, a method for calculating the power limit of a fuel cell includes the following steps:

[0045] Calculate the heat dissipation capacity of the current radiator 6, where the heat dissipation capacity is determined based on the actual heat dissipation under different vehicle speeds, the rotation speed of the fan 7, and the coolant flow rate through the radiator during the actual operation of the vehicle.

[0046] Based on the heat dissipation capacity and the polarization curve of the fuel cell, preliminarily determine the power limit value at the current vehicle speed.

[0047] Adjust the power limit value according to the actual temperature of the fuel cell.

[0048] In an embodiment of the present application, the polarization curve of the fuel cell is a curve that describes the relationship between the output voltage of the fuel cell and the current density. It reflects the performance of the fuel cell at different operating currents and is an important tool for evaluating the performance of the fuel cell.

[0049] As Figure 2 shown, the fuel cell thermal management system involved in an embodiment of the present application includes a water pump 1, a three-way valve 5, a radiator 6, a radiator outlet temperature sensor 8, a stack inlet temperature sensor 2, a stack outlet temperature sensor 4, and a fan 7. Among them, the stack inlet temperature sensor 2 is arranged at the inlet end of the stack 3, and the stack outlet temperature sensor 4 is arranged at the outlet end of the stack 3. The radiator outlet temperature sensor 8 is arranged at the outlet end of the radiator 6. The fan 7 is arranged on one side of the radiator 6. The working principle of the fuel cell thermal management system is as follows: The three-way valve 5 distributes the coolant in two loops. When the opening of the three-way valve 5 is the smallest, the flow rate through the radiator 6 is 0 at this time, and the radiator 6 does not dissipate heat. When the opening of the three-way valve 5 is the largest, the flow rate through the radiator 6 is the largest at this time; the radiator 6 plays a cooling role, and the coolant entering the radiator 6 will be cooled by the radiator 6; the water pump 1 ensures the flow of the coolant in the entire fuel cell thermal management system to achieve the purpose of taking away heat.

[0050] In an embodiment of the present application, the stack 3 is the core component of the fuel cell, which is composed of multiple single cells combined in series or in parallel.

[0051] In a possible embodiment, calculating the heat dissipation capacity of the current radiator 6 includes:

[0052] First, record the actual heat dissipation under different vehicle speeds, the rotation speed of the fan 7, and the coolant flow rate through the radiator 6 during the actual operation of the vehicle. The vehicle speed and the rotation speed of the fan 7 are obtained by sensor acquisition. The coolant flow rate through the radiator 6 is obtained by looking up a table according to the rotation speed of the water pump 1 and the opening of the three-way valve 5. The actual heat dissipation is calculated according to the following formula:

[0053] Q act =cq(Tout -T rad )

[0054] Wherein, Q act represents the actual heat dissipation; c represents the specific heat capacity of the coolant; q represents the coolant flow rate through the radiator; T out represents the temperature at the outlet of the fuel cell stack (acquired by the temperature sensor at the outlet of the fuel cell stack); T rad represents the temperature at the outlet of the radiator (acquired by the radiator outlet temperature sensor 8).

[0055] Next, according to the corresponding relationship between the vehicle speed, the rotational speed of the fan 7, the coolant flow rate through the radiator 6, and the heat dissipation capacity, a relational expression for the heat dissipation capacity with respect to the vehicle speed, the rotational speed of the fan, and the coolant flow rate through the radiator is obtained by fitting; specifically:

[0056] During the actual operation of the vehicle, at the current ambient temperature, the heat dissipation capacity is mainly related to the rotational speed of the fan 7, the coolant flow rate through the radiator 6, and the vehicle speed, that is, Q = f Q (n fan , q, v), where Q represents the heat dissipation capacity; n fan represents the rotational speed of the fan; v represents the vehicle speed.

[0057] When the fuel cell is just started, since there is less recorded data, the relational expression can be defined as a ternary linear relational expression at this time, that is, Q = k1n fan + k2q + k3v + b, and then according to the corresponding relationship between the vehicle speed, the rotational speed of the fan 7, the coolant flow rate through the radiator 6, and the heat dissipation capacity, the parameters k1, k2, k3, and b in the ternary linear relational expression are solved. As more and more data is recorded, the relational expression will be directly fitted subsequently, and at this time, the relational expression may be a ternary quadratic, ternary cubic relational expression, etc.

[0058] Substitute the maximum rotational speed of the fan and the maximum coolant flow rate through the radiator into the relational expression Q = f Q (n fan , q, v) of the heat dissipation capacity with respect to the rotational speed of the fan, the coolant flow rate through the radiator, and the vehicle speed, to obtain the maximum heat dissipation capacity at the current vehicle speed, that is, Q max = f Q (n fan_max , q max , v). Wherein, Q max represents the maximum heat dissipation capacity; n fan_max represents the maximum rotational speed of the fan; q max represents the maximum coolant flow rate through the radiator.

[0059] Each time the fuel cell is started and operated, the relational expression Q = f Q (n fan, q, v), since this relationship is often updated according to the current usage, the accuracy of calculating the maximum heat dissipation capacity can be guaranteed.

[0060] In a possible embodiment, initially determining the power limit value at the current vehicle speed specifically includes:

[0061] During the actual power generation process of the fuel cell, determine the one-to-one correspondence between the heat generation amount and the power according to the polarization curve of the fuel cell. The heat generation amount needs to be dissipated by the radiator 6. When the heat generation amount is equal to the maximum heat dissipation capacity at the current vehicle speed, the power corresponding to the heat generation amount at this time is the power limit value. Therefore, the maximum heat dissipation capacity can be determined according to the maximum heat generation amount, and then the maximum power is initially determined, and this maximum power is used as the power limit value at the initially determined current vehicle speed, that is, P max = P max_ini . Among them, P max_ini represents the maximum power; P max represents the power limit value at the initially determined current vehicle speed.

[0062] As the fuel cell decays and its health state deteriorates, at the same heat generation amount, the power of the fuel cell will become smaller. Therefore, it is necessary to monitor the change of the health state of the fuel cell in real time and correct the power limit value corresponding to the heat generation amount according to the health state of the fuel cell, that is, P max = P max_ini f γ (γ), where γ represents the health state, and f γ (γ) is a function of the health state of the fuel cell.

[0063] In a possible embodiment, adjusting the power limit value according to the actual temperature of the fuel cell includes:

[0064] When the opening of the three-way valve 5 is the largest, all the coolant flows through the radiator 6. If the fan 7 rotates at the highest speed and has the largest flow rate at this time, it means that the radiator 6 reaches the maximum heat dissipation capacity.

[0065] When the maximum heat dissipation capacity of the radiator 6 is reached, obtain the actual outlet temperature, actual inlet temperature, target outlet temperature, and target inlet temperature of the fuel cell, and set the error threshold allowed at the outlet and the error threshold allowed at the inlet. If |T out_tar - T out | ≤ ΔT out and |T intar - T in | ≤ ΔT in both hold, it means that both the actual inlet temperature and the actual outlet temperature of the fuel cell are within the required control error range at this time, then use the actual power of the current fuel cell as the power limit value at the current vehicle speed, that is, P max = Pact . Among them, T out represents the actual outlet temperature, T in represents the actual inlet temperature, T out_tar represents the target outlet temperature, T out_in represents the target inlet temperature, ΔT out represents the allowable error threshold at the outlet, ΔT in represents the allowable error threshold at the inlet, P act represents the actual power of the current fuel cell.

[0066] If the radiator 6 reaches its maximum heat dissipation capacity, and at this time ΔT out +T out <T out_tar or ΔT in +T in <T in_tar , it indicates that the current power limit value is too high and needs to be reduced. The specific implementation method is as follows:

[0067] First, take the heat dissipation of the radiator 6 at this time as the maximum heat dissipation capacity of the radiator 6 at the current vehicle speed, and based on this heat dissipation, initially obtain the power limit value, that is, P max =P max_ini f γ (γ);

[0068] Then, take the larger value of the difference between the target outlet temperature and the actual outlet temperature (i.e., T out_tar -T out ) and the difference between the target inlet temperature and the actual inlet temperature (T in_tar -T in ) as the error value, that is, ΔT max , and input the error value into the PID feedback control to obtain the corrected power.

[0069] Among them, inputting the error value into the PID feedback control to obtain the corrected power is specifically:

[0070]

[0071] Among them, P cof represents the corrected power, k p represents the proportional control coefficient, k i represents the integral control coefficient, k d represents the differential control coefficient.

[0072] Finally, calculate the final power limit value at the current vehicle speed based on the corrected power and the initially obtained power limit value, that is, P max =P max_ini f γ (γ)+P cof .

[0073] If the radiator 6 has not reached its maximum heat dissipation capacity and the actual power of the fuel cell is less than the power limit value (i.e., P act <P max ), then the power limit value at the current vehicle speed remains P max =P max_ini f γ (γ).

[0074] If the radiator 6 has not reached its maximum heat dissipation capacity, but the actual power of the fuel cell is equal to the power limit value (i.e., P act =P max ), it indicates that the power limit value can be further increased. The specific implementation method is to re-determine the relationship Q = f Q (n fan , q, v). Then the power limit value at the current vehicle speed is the power value corresponding to the maximum heat generation calculated after re-determining the relationship, that is, at this time P max =P max_ini f γ (γ).

[0075] As Figure 3 shown, in the embodiment of the present application, a fuel cell power limit calculation system includes a memory and a controller. When the computer-readable program stored in the memory is called by the controller, it can execute the steps of the fuel cell power limit calculation method in the embodiment of the present application.

[0076] In the embodiment of the present application, a vehicle adopts the fuel cell power limit calculation system in the embodiment of the present application.

[0077] The above embodiments are preferred embodiments of the present invention. However, the embodiments of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications made without departing from the spirit and principle of the present invention shall be equivalent replacement methods and shall be included in the protection scope of the present invention.

Claims

1. A fuel cell power limit calculation method, characterized in that, The method includes the following steps: Calculating the heat dissipation capacity of the current radiator (6), where the heat dissipation capacity is determined based on the actual heat dissipation amount under different vehicle speeds, the rotational speed of the fan (7), and the coolant flow rate through the radiator (6) during the actual operation of the vehicle; Preliminarily determining the power limit value at the current vehicle speed according to the heat dissipation capacity and the polarization curve of the fuel cell; Adjusting the power limit value according to the actual temperature of the fuel cell.

2. The fuel cell power limit calculation method according to claim 1, wherein Calculating the heat dissipation capacity of the current radiator (6) includes: Recording the actual heat dissipation amount under different vehicle speeds, the rotational speed of the fan (7), and the coolant flow rate through the radiator (6) during the actual operation of the vehicle; Fitting a relationship between the heat dissipation capacity and the vehicle speed, the fan rotational speed, and the coolant flow rate through the radiator according to the corresponding relationship between the vehicle speed, the rotational speed of the fan (7), the coolant flow rate through the radiator (6), and the heat dissipation capacity; Substituting the maximum fan rotational speed and the maximum coolant flow rate through the radiator into the relationship to obtain the maximum heat dissipation capacity at the current vehicle speed.

3. The fuel cell power limit calculation method according to claim 2, characterized in that The preliminary determination of the current power limit value includes: During the actual power generation process of the fuel cell, determining the one-to-one correspondence between the heat generation amount and the power according to the polarization curve. When the heat generation amount is equal to the maximum heat dissipation capacity at the current vehicle speed, the power corresponding to the heat generation amount at this time is the power limit value.

4. The fuel cell power limit calculation method according to claim 3, wherein In the step of preliminarily determining the power limit value at the current speed, it further includes: Real-time monitoring the change in the health state of the fuel cell, and correcting the power limit value corresponding to the heat generation amount according to the health state of the fuel cell.

5. The fuel cell power limit calculation method according to claim 1, characterized in that Adjusting the power limit value according to the actual temperature of the fuel cell includes: When the radiator (6) reaches the maximum heat dissipation capacity, obtaining the actual outlet temperature, the target outlet temperature, the actual inlet temperature, and the target inlet temperature of the fuel cell, and setting the outlet temperature error threshold and the inlet temperature error threshold; If the sum of the target outlet temperature and the outlet temperature error threshold is less than the target outlet temperature, or the sum of the target inlet temperature and the inlet temperature error threshold is less than the target inlet temperature, then adjusting the power limit value according to the PID feedback control; and controlling the output power of the fuel cell according to the adjusted power limit value.

6. The fuel cell power limit calculation method according to claim 5, wherein Adjusting the power limit value according to the actual temperature of the fuel cell further includes: When the radiator (6) does not reach the maximum heat dissipation capacity, but the actual power of the fuel cell is equal to the power limit value, re-determining the relationship between the heat dissipation capacity and the vehicle speed, the fan rotational speed, and the coolant flow rate through the radiator, and taking the power value corresponding to the maximum heat generation amount calculated after re-determining the relationship as the power limit value at the current vehicle speed.

7. The fuel cell power limit calculation method according to claim 5, characterized in that, Adjusting the power limit value according to the actual temperature of the fuel cell further includes: When the radiator (6) reaches the maximum heat dissipation capacity, if the absolute difference between the target outlet temperature and the actual outlet temperature is less than or equal to the outlet temperature error threshold, and the absolute difference between the target inlet temperature and the actual inlet temperature is less than or equal to the inlet temperature error threshold, then taking the actual power of the current fuel cell as the power limit value at the current vehicle speed; When the radiator (6) does not reach the maximum heat dissipation capacity, and the actual power of the fuel cell is less than the power limit value, maintaining the current power limit value unchanged.

8. The fuel cell power limit calculation method according to claim 5, characterized in that, The adjusting the power limit value according to the PID feedback control includes: Take the heat dissipation of the current radiator (6) as the maximum heat dissipation capacity of the radiator (6) at the current vehicle speed, and initially obtain the power limit value. Take the larger value between the difference between the target outlet temperature and the actual outlet temperature and the difference between the target inlet temperature and the actual inlet temperature as the error value, and input the error value into the PID feedback control to obtain the corrected power. Calculate the power limit value at the final current vehicle speed based on the corrected power and the initially obtained power limit value.

9. A fuel cell power limit calculation system, characterized in that It includes a memory and a controller. A computer-readable program is stored in the memory. When the computer-readable program is called by the controller, it can execute the steps of the fuel cell power limit calculation method according to any one of claims 1 to 8.

10. A vehicle, characterized in that, Adopt the fuel cell power limit calculation system according to claim 9.

Images