A control method and apparatus for a vehicle fuel cell system

Abstract

The application discloses a control method and device of a vehicle fuel cell system. The control method of the vehicle fuel cell system comprises the following steps: obtaining a predicted power request change rate of the vehicle; determining a control mode of the fuel cell system according to the predicted power request change rate and a preset power change rate; if the predicted power request change rate is greater than the preset power change rate, controlling the fuel cell system in a first control mode; otherwise, controlling the fuel cell system in a second control mode. Therefore, the method can realize the following: according to the predicted power request change rate and the preset power change rate of the whole vehicle, a corresponding control mode of the fuel cell system is reasonably selected, the power request of the whole vehicle can be met by quickly pulling the load, especially under the working condition of frequent power change, the system can still realize the quick response and real-time following of the power, thereby the dependence on the power battery can be reduced, and the service life of the battery and the electric propeller can be prolonged.

Description

Technical Field

[0001] This invention relates to the field of vehicle control technology, and in particular to a control method and apparatus for a vehicle fuel cell system. Background Technology

[0002] Fuel cell systems often fail to keep up with power changes in real time under extreme conditions such as rapid changes in vehicle power, resulting in poor system control. Existing solutions generally involve open-loop control or limiting the power ramp rate.

[0003] However, regarding the first type of open-loop calibration, although there are not many control problems in the early stages, the performance of components and the fuel cell stack will degrade as the usage time increases. Open-loop control cannot compensate for and correct performance degradation in a timely manner, and will reduce the system performance. At the same time, this will also cause irreversible damage to the fuel cell stack, thereby shortening the life of the fuel cell stack. The second approach, which limits the rate of power change, will seriously affect the vehicle's power performance and driving experience, or can only meet the vehicle's power performance by increasing the capacity of the power battery, but this will increase the vehicle's manufacturing cost and space layout. Summary of the Invention

[0004] This invention provides a control method and apparatus for a vehicle fuel cell system to meet the power requirements of the vehicle and achieve rapid power response and real-time tracking.

[0005] According to one aspect of the present invention, a control method for a vehicle fuel cell system is provided, the control method comprising:

[0006] Obtain the predicted power request change rate of the vehicle;

[0007] The control mode of the fuel cell system is determined based on the predicted power request change rate and the preset power change rate.

[0008] If the predicted power request change rate is greater than the preset power change rate, the fuel cell system is controlled in the first control mode.

[0009] Otherwise, the fuel cell system is controlled in the second control mode.

[0010] Optionally, the fuel cell system includes at least an air compressor and a back pressure valve;

[0011] The control of the fuel cell system in the first control mode includes:

[0012] The vehicle power change control strategy is adjusted according to the predicted power request change rate.

[0013] Obtain the current power request value of the vehicle, and determine the current target power request value by combining it with the adjusted vehicle power change control strategy;

[0014] The target regulating flow rate of the air compressor is determined based on the correspondence between the current target power request value and the air compressor flow rate;

[0015] The target regulating pressure of the back pressure valve is determined based on the correspondence between the current target power request value and the back pressure valve pressure.

[0016] When adjusting the back pressure valve pressure according to the target adjustment pressure, a preset correction coefficient is added to accelerate the back pressure valve pressure adjustment rate.

[0017] Optionally, the vehicle power change control strategy is to control the rate of change of vehicle power according to a ramp curve;

[0018] The method of adjusting the vehicle power change control strategy according to the predicted power request change rate includes:

[0019] The slope of the ramp curve is adjusted based on the predicted power request change rate and the correspondence between the predicted power request change rate and the slope of the ramp curve, so as to regulate the rate of change of vehicle power.

[0020] Optionally, the relationship between the predicted power request change rate and the slope of the ramp curve is as follows:

[0021] The rate of change of the predicted power request is positively correlated with the slope of the ramp curve.

[0022] Optionally, obtaining the current power request value of the vehicle and determining the current target power request value in conjunction with the adjusted vehicle power change control strategy includes:

[0023] The current power request value of the vehicle is obtained, and the current target power request value is determined by combining it with the slope curve after slope adjustment.

[0024] Optionally, when adjusting the back pressure valve pressure according to the target adjustment pressure, adding a preset correction coefficient to accelerate the back pressure valve pressure adjustment rate includes:

[0025] When adjusting the back pressure valve opening according to the target adjustment pressure to adjust the back pressure valve pressure, the back pressure valve opening is multiplied by the correction coefficient to accelerate the pressure adjustment rate of the back pressure valve.

[0026] Optionally, the fuel cell system includes at least an air compressor and a back pressure valve;

[0027] The control of the fuel cell system in the second control mode includes:

[0028] Obtain the current power request value of the vehicle, and determine the current target power request value according to the vehicle power change control strategy;

[0029] The target regulating flow rate of the air compressor is determined based on the correspondence between the current target power request value and the air compressor flow rate;

[0030] The target regulating pressure of the back pressure valve is determined based on the correspondence between the current target power request value and the back pressure valve pressure.

[0031] Optionally, the vehicle power change control strategy is to control the rate of change of vehicle power according to a ramp curve;

[0032] The step of obtaining the current power request value of the vehicle and determining the current target power request value according to the vehicle power change control strategy includes:

[0033] The current power request value of the vehicle is obtained, and the current target power request value is determined according to the ramp curve; wherein the slope of the ramp curve is a fixed value.

[0034] Optionally, the vehicle includes: an accelerator pedal and a map navigation system;

[0035] The step of obtaining the predicted power request change rate of the vehicle includes:

[0036] The predicted power request of the vehicle is obtained based on the accelerator pedal opening and the map navigation system prediction.

[0037] Obtain the current power request value of the vehicle;

[0038] The predicted power request change rate is obtained based on the vehicle's predicted power request and the current power request value.

[0039] According to another aspect of the present invention, a control device for a vehicle fuel cell system is provided, the control device for the vehicle fuel cell system comprising:

[0040] A predicted power request change rate acquisition module is used to acquire the predicted power request change rate of the vehicle.

[0041] A control mode determination module for a fuel cell system is used to determine the control mode of the fuel cell system based on the predicted power request change rate and the preset power change rate.

[0042] If the predicted power request change rate is greater than the preset power change rate, the fuel cell system is controlled in the first control mode.

[0043] Otherwise, the fuel cell system is controlled in the second control mode.

[0044] The technical solution of this invention provides a control method and apparatus for a vehicle fuel cell system. The control method includes: acquiring the predicted power request change rate of the vehicle; determining a control mode for the fuel cell system based on the predicted power request change rate and a preset power change rate; if the predicted power request change rate is greater than the preset power change rate, controlling the fuel cell system in a first control mode; otherwise, controlling the fuel cell system in a second control mode. Therefore, this method can achieve the following: rationally selecting the control mode corresponding to triggering the fuel cell system based on the predicted power request change rate and the preset power change rate of the vehicle. This allows for rapid load loading and meets the vehicle's power request, especially under conditions of frequent power changes, enabling the system to still achieve rapid power response and real-time tracking. This reduces reliance on the power battery and extends the service life of both the battery and the electric propulsion system.

[0045] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0046] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0047] Figure 1 This is a flowchart of a control method for a vehicle fuel cell system provided in an embodiment of the present invention;

[0048] Figure 2 This is a flowchart of another control method for a vehicle fuel cell system provided in an embodiment of the present invention;

[0049] Figure 3 This is a control state flowchart of a vehicle fuel cell system provided in an embodiment of the present invention;

[0050] Figure 4 This is a structural block diagram of a control device for a vehicle fuel cell system provided in an embodiment of the present invention. Detailed Implementation

[0051] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0052] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention 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 the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0053] The inventors discovered that the lifespan of a fuel cell is closely related to the air supply to the cathode side. During operation, the flow rate and pressure on the cathode side are primarily controlled by the combined operation of the air compressor and the back pressure valve. The controller adjusts the compressor speed and back pressure valve position in real time to ensure that the air flow rate and infeed pressure on the cathode side remain within the theoretically set range at different power points, thus guaranteeing a continuous and stable output of the set power value. Under conditions of rapid power changes and steady-state operation, the control algorithm regulates the compressor speed and back pressure valve position to ensure that the air flow rate and infeed pressure on the cathode side are always within the theoretically set range. This is particularly effective for situations with frequent and rapid power changes, allowing for rapid load adjustments to meet real-time power requirements and reducing over-reliance on the battery under extreme conditions such as rapid acceleration, as well as the fuel cell system's inability to keep up with real-time demands.

[0054] The traditional solution is usually to implement open-loop control, which means that after the parameters of each power point are calibrated and verified in advance on the test bench, the air compressor and back pressure valve are mechanically adjusted based on the data calibrated in the early stage. Alternatively, some methods limit the power ramp-up rate, so that the power does not fluctuate drastically in a short period of time, thus making the power change relatively stable.

[0055] However, regarding the first type of open-loop calibration, although there are not many control problems in the early stages, the performance of components and the fuel cell stack will degrade as the usage time increases. Open-loop control cannot compensate for and correct performance degradation in a timely manner, and will reduce the system performance. At the same time, this will also cause irreversible damage to the fuel cell stack, thereby shortening the life of the fuel cell stack. The second approach, which limits the rate of power change, will seriously affect the vehicle's power performance and driving experience, or can only meet the vehicle's power performance by increasing the capacity of the power battery, but this will increase the vehicle's manufacturing cost and space layout.

[0056] Therefore, embodiments of the present invention provide a control method and apparatus for a vehicle fuel cell system to meet the power request of the vehicle and achieve rapid power response and real-time tracking.

[0057] Figure 1 This is a flowchart illustrating a control method for a vehicle fuel cell system provided in an embodiment of the present invention. This embodiment is applicable to vehicle system control platforms, enabling the fuel cell system to follow power changes and improving the rationality and reliability of system control. This method can be executed by a control device for the vehicle fuel cell system, which can be implemented in hardware and / or software and can be configured within the vehicle system control platform. Figure 1 As shown, the method includes:

[0058] S110, Obtain the predicted power request change rate of the vehicle.

[0059] Among them, vehicles can be passenger vehicles.

[0060] The predicted power request change rate is used to predict the future power change trend of the vehicle, such as how fast or slow the power will change. If the predicted power request change rate is large, it indicates that the vehicle's power is changing rapidly, and the vehicle may be operating under conditions of frequent power fluctuations. If the predicted power request change rate is small, it indicates that the vehicle's power is relatively stable, and the vehicle may be operating under conditions of stable power.

[0061] The predicted power request change rate of the vehicle can be obtained from the vehicle controller. The vehicle controller can comprehensively predict the predicted power request change rate of the vehicle based on information such as the vehicle's actual power status, road conditions, road conditions ahead, and vehicle speed.

[0062] S120. Determine the control mode of the fuel cell system based on the predicted power request change rate and the preset power change rate.

[0063] The preset power change rate is a threshold for judging whether the vehicle power changes frequently. The specific value can be set according to the actual situation, and no specific limit is made here.

[0064] By comparing the predicted power request rate of change with the preset power change rate, the power change trend of the vehicle can be predicted, and it can be determined whether the vehicle is in a condition of frequent power changes. Therefore, by selecting an appropriate control mode for the fuel cell system based on the predicted power request rate of change and the preset power change rate, the system's power can be rapidly responded to and tracked in real time.

[0065] S130. If the predicted power request change rate is greater than the preset power change rate, then the fuel cell system is controlled in the first control mode.

[0066] If the predicted rate of change of power request is greater than the preset rate of change of power, it indicates that the vehicle is in a condition of frequent power changes. In this case, the fuel cell system operates in the first control mode to ensure rapid system power response and real-time tracking even under conditions of frequent power changes. The first control mode is a dynamic control mode.

[0067] S140. If the predicted power request change rate is less than or equal to the preset power change rate, the fuel cell system is controlled in the second control mode.

[0068] If the predicted power request change rate is less than or equal to the preset power change rate, it indicates that the vehicle is in a stable power operation condition. In this case, the fuel cell system operates in the second control mode to meet the system power demand. The second control mode is the normal control mode.

[0069] In the technical solution of this embodiment, the working principle of the control method of the vehicle fuel cell system is as follows: (Refer to...) Figure 1 First, the predicted power request change rate of the vehicle is acquired in real time. Then, the control mode of the fuel cell system is determined based on the predicted power request change rate and the preset power change rate. Specifically, it is determined whether the predicted power request change rate is greater than the preset power change rate. If the predicted power request change rate is greater than the preset power change rate, the fuel cell system is controlled in the first control mode; otherwise, the fuel cell system is controlled in the second control mode. Therefore, this method can achieve the following: by rationally selecting the corresponding control mode for triggering the fuel cell system based on the predicted power request change rate and the preset power change rate of the vehicle, it can achieve rapid load loading and meet the power request of the vehicle. Especially under conditions of frequent power changes, the system can still achieve rapid power response and real-time following, thereby reducing dependence on the power battery and extending the service life of the battery and electric propulsion system.

[0070] Figure 2This is a flowchart of another control method for a vehicle fuel cell system provided in an embodiment of the present invention. As one implementation, this embodiment, based on the above embodiments, elaborates in detail on the specific implementation methods of the first control mode (dynamic control mode) and the second control mode (normal control mode). Optionally, as... Figure 2 As shown, the method includes:

[0071] S210. Obtain the predicted power request change rate of the vehicle;

[0072] Optionally, the vehicle includes an accelerator pedal and a map navigation system. The step of obtaining the vehicle's predicted power request change rate includes: obtaining the vehicle's predicted power request based on the accelerator pedal opening and the map navigation system's prediction; obtaining the vehicle's current power request value; and obtaining the predicted power request change rate based on the vehicle's predicted power request and the current power request value.

[0073] Specifically, by analyzing the accelerator pedal opening and the road scene from the map navigation system, road conditions can be identified in advance, allowing for direct prediction of the vehicle's power request to the fuel cell system (i.e., predicting the power request rate). For example, the vehicle's power request to the fuel cell system can be predicted by judging the rate of change of the accelerator sensor's position and the uphill or highway conditions in the road scene from the map navigation system.

[0074] The rate of change of a vehicle's power request can be calculated based on its predicted power request and current power request value. For example, assuming the vehicle's power request at the current sampling time (or time period) is the current power request value, and the vehicle's power request at the next sampling time (or time period) is the predicted power request value, then the rate of change of the vehicle's power request can be calculated based on the vehicle's predicted power request value, current power request value, and the difference between the two sampling times.

[0075] S220. Determine whether the predicted change rate of the power request is greater than the preset change rate of the power. If yes, proceed to steps S231 to S235; otherwise, proceed to steps S241 to S243.

[0076] The process involves determining whether the predicted power change rate exceeds the preset power change rate. If so, it indicates the vehicle is in a state of frequent power changes, and the fuel cell system operates in the first control mode, i.e., steps S231 to S235 are executed. Otherwise, it indicates the vehicle is in a state of stable power operation, and the fuel cell system operates in the second control mode, i.e., steps S241 to S243 are executed. The fuel cell system includes at least an air compressor and a back pressure valve.

[0077] S231. Adjust the vehicle power change control strategy according to the predicted power request change rate.

[0078] The vehicle power change control strategy involves controlling the rate of change of vehicle power according to a ramp curve. In other words, the rate of change of vehicle power is adjusted according to the ramp signal, rather than being abrupt.

[0079] Optionally, adjusting the vehicle power change control strategy according to the predicted power request change rate includes: adjusting the slope of the ramp curve according to the predicted power request change rate and the correspondence between the predicted power request change rate and the slope of the ramp curve, so as to adjust the rate of change of vehicle power.

[0080] There is a certain correlation between the predicted power request change rate and the slope of the ramp curve. Therefore, when the predicted power request change rate is known, the slope of the ramp curve can be adjusted based on the correlation between the two, and the vehicle power change can be adjusted based on the ramp curve after slope adjustment.

[0081] Optionally, the relationship between the predicted power request change rate and the slope of the ramp curve is as follows: the rate of change of the predicted power request is positively correlated with the change of the slope of the ramp curve.

[0082] S232. Obtain the current power request value of the vehicle and determine the current target power request value in combination with the adjusted vehicle power change control strategy.

[0083] The current power request value is the vehicle's current actual power request value. Since the vehicle's power adjustment changes at a certain rate, i.e., according to the vehicle power change control strategy, the current target power request value is the dynamically changing target power adjustment value obtained according to the vehicle power change control strategy.

[0084] Optionally, obtaining the vehicle's current power request value and determining the current target power request value in conjunction with the adjusted vehicle power change control strategy includes: obtaining the vehicle's current power request value and determining the current target power request value in conjunction with the slope-adjusted ramp curve.

[0085] In the first control mode, the vehicle power change control strategy is dynamically adjusted according to the predicted power request change rate. That is, the slope of the ramp curve is dynamically adjusted according to the predicted power request change rate and the correspondence between the predicted power request change rate and the slope of the ramp curve. By substituting the current power request value of the vehicle into the ramp curve after slope adjustment, the power value that the whole vehicle needs to adjust at present can be calculated, that is, the current target power request value.

[0086] S233. Determine the target regulating flow rate of the air compressor based on the correspondence between the current target power request value and the air compressor flow rate.

[0087] The correspondence between the current target power request value and the air compressor flow rate is defined in a power-to-air compressor flow rate lookup table. For each current target power request value determined, the corresponding target regulating flow rate of the air compressor can be determined according to the lookup table. Therefore, based on the dynamically adjusted current target power request value of the vehicle and the correspondence between the current target power request value and the air compressor flow rate, the target regulating flow rate of the air compressor can be dynamically output.

[0088] Specifically, in the first control mode, due to the large rate of change in the predicted power request of the vehicle, the vehicle is in a condition of frequent power changes. Therefore, the slope of the ramp curve controlling the rate of change in vehicle power is dynamically adjusted based on this predicted power request change rate. Then, the dynamically adjusted ramp curve can dynamically output the vehicle's current target power request value. Finally, based on the dynamically output current target power request value and the correspondence between the current target power request value and the air compressor flow rate, the target adjustment flow rate of the air compressor can be determined in real time. This allows the air compressor to adjust its flow rate in real time according to the dynamically adjusted target adjustment flow rate, thereby meeting the vehicle's power tracking and rapid load-bearing requirements under conditions of frequent power changes.

[0089] One specific way to adjust the flow rate of an air compressor is to adjust the flow rate by changing the speed of the air compressor.

[0090] S234. Determine the target regulating pressure of the back pressure valve based on the correspondence between the current target power request value and the back pressure valve pressure.

[0091] The correspondence between the current target power request value and the back pressure valve pressure is defined in a power-back pressure valve pressure reference table. For each current target power request value determined, the corresponding target adjustment pressure of the back pressure valve can be determined according to the reference table. Therefore, based on the dynamically adjusted current target power request value of the vehicle and the correspondence between the current target power request value and the back pressure valve pressure, the target adjustment pressure of the back pressure valve can be dynamically output.

[0092] Specifically, in the first control mode, due to the large rate of change in the predicted power request of the vehicle, the vehicle is in a condition of frequent power changes. Therefore, the slope of the ramp curve controlling the rate of change in vehicle power is dynamically adjusted based on this predicted power request change rate. Then, the dynamically adjusted ramp curve can dynamically output the vehicle's current target power request value. Finally, based on the dynamically output current target power request value and its correspondence with the back pressure valve pressure, the target adjustment pressure of the back pressure valve can be determined in real time. This allows the back pressure valve to adjust the air compressor pressure in real time according to the dynamically adjusted target adjustment pressure, thereby meeting the vehicle's power tracking and rapid load-bearing requirements under conditions of frequent power changes.

[0093] The specific implementation method of back pressure valve pressure regulation can be: adjusting the opening degree of the back pressure valve or the rate of change of the position of the back pressure valve to regulate the flow rate.

[0094] S235. When adjusting the back pressure valve pressure according to the target adjustment pressure, a preset correction coefficient is added to accelerate the back pressure valve pressure adjustment rate.

[0095] In this context, when adjusting the back pressure valve pressure according to the target adjustment pressure, adding a preset correction coefficient means that while the back pressure valve is adjusting the back pressure according to the target adjustment pressure, a certain preset correction coefficient is also added to the pressure adjustment process, which can accelerate the back pressure valve pressure adjustment rate.

[0096] The preset correction coefficient can be set according to the actual situation, and no specific limitation is made here.

[0097] Optionally, when adjusting the back pressure valve pressure according to the target adjustment pressure, a preset correction coefficient is added to accelerate the back pressure valve pressure adjustment rate, including: when adjusting the back pressure valve opening according to the target adjustment pressure to adjust the back pressure valve pressure, multiplying the back pressure valve opening by the correction coefficient to accelerate the back pressure valve pressure adjustment rate.

[0098] In this context, when adjusting the back pressure valve pressure according to the target adjustment pressure, adding a preset correction coefficient means that when the back pressure valve adjusts its opening size according to the target adjustment pressure, the opening size of the back pressure valve is also multiplied by a certain preset correction coefficient, thereby accelerating the back pressure valve pressure adjustment rate.

[0099] In this process, when the back pressure valve adjusts its pressure according to the target adjustment pressure, a certain preset correction coefficient is also added to the back pressure valve to accelerate the pressure adjustment rate of the back pressure valve. This makes the pressure adjustment rate of the back pressure valve significantly greater than the flow adjustment rate of the air compressor, thereby ensuring that the control flow entering the fuel cell system is sufficient and that the pressure is allowed to be slightly lower than the set pressure value.

[0100] The working principle of the fuel cell system in the first control mode is as follows: Since the predicted power request change rate of the vehicle is greater than the preset power request change rate, it indicates that the vehicle is in a condition of frequent power changes. To achieve vehicle power tracking and rapid load loading, the vehicle power change control strategy is dynamically adjusted according to the predicted power request change rate. For example, the slope of the ramp curve controlling the rate of vehicle power change is dynamically adjusted. By combining the vehicle's current power request value with the dynamically adjusted ramp curve, the vehicle's current target power request value can be obtained in real time. Based on the correspondence between the current target power request value and the air compressor flow rate, and the correspondence between the current target power request value and the back pressure valve pressure, the target regulating flow rate of the air compressor and the target regulating pressure of the back pressure valve are determined respectively. Finally, based on the target regulating flow rate and target regulating pressure, the air compressor and back pressure valve are rapidly adjusted to meet the vehicle's power demand and achieve rapid load loading. This allows the vehicle to still achieve real-time power tracking even under conditions of frequent power changes, reducing reliance on the power battery and extending the service life of the power battery and fuel cell stack. Simultaneously, while the back pressure valve adjusts its pressure according to the target adjustment pressure, a certain preset correction coefficient is also added to the back pressure valve to accelerate the pressure adjustment rate. This ensures that the pressure adjustment rate of the back pressure valve is significantly greater than the flow adjustment rate of the air compressor, thereby ensuring that the air flow entering the fuel cell system is sufficient and that the pressure is allowed to be slightly lower than the set pressure value. When the vehicle power demand stabilizes (i.e., when the predicted demand change rate is less than or equal to the preset power change rate), the control mode of the fuel cell system switches to the second control mode (i.e., the normal control mode).

[0101] S241. Obtain the current power request value of the vehicle and determine the current target power request value according to the vehicle power change control strategy.

[0102] In the second control mode, since the predicted power request change rate of the vehicle is less than or equal to the preset power request change rate, it indicates that the vehicle is in a stable power operation condition. Under the stable power operation condition, the requirement for the speed of power adjustment is not high (such as the absence of rapid load hauling). Therefore, there is no need to dynamically adjust the vehicle power change control strategy. The current target power request value of the vehicle can be determined directly based on the real-time acquired current power request value of the vehicle and the vehicle power change control strategy, which can meet the power demand under the stable power operation condition.

[0103] Optionally, the vehicle power change control strategy is to control the rate of vehicle power change according to a ramp curve; to obtain the current power request value of the vehicle and to determine the current target power request value according to the vehicle power change control strategy, including: obtaining the current power request value of the vehicle and determining the current target power request value according to the ramp curve; wherein the slope of the ramp curve is a fixed value.

[0104] The slope of the ramp curve can be set according to the actual situation, and no specific limit is set here.

[0105] S242. Determine the target regulating flow rate of the air compressor based on the correspondence between the current target power request value and the air compressor flow rate.

[0106] Specifically, in the second control mode, since the vehicle's predicted power request changes at a small rate, the vehicle operates under stable power conditions. Therefore, there is no need to dynamically adjust the vehicle power change control strategy. Instead, the current target power request value is determined directly based on the real-time acquired current power request value and the vehicle power change control strategy (such as a ramp curve). Finally, based on the dynamically output current target power request value and the correspondence between the current target power request value and the air compressor flow rate, the target adjustment flow rate of the air compressor can be determined in real time. This allows the air compressor to adjust its flow rate in real time according to the dynamically determined target adjustment flow rate to meet the vehicle's power requirements under stable power operating conditions.

[0107] S243. Determine the target regulating pressure of the back pressure valve based on the correspondence between the current target power request value and the back pressure valve pressure.

[0108] Specifically, in the second control mode, since the predicted power request change rate of the vehicle is small and the vehicle is in a stable power operation condition, there is no need to dynamically adjust the vehicle power change control strategy. The current target power request value of the vehicle is determined directly based on the real-time acquired current power request value of the vehicle and the vehicle power change control strategy (such as a ramp curve). Finally, based on the dynamically output current target power request value of the vehicle and the correspondence between the current target power request value and the back pressure valve pressure, the target adjustment pressure of the back pressure valve can be determined in real time. This allows the back pressure valve to adjust the air compressor pressure in real time according to the dynamically adjusted target adjustment pressure to meet the power demand of the vehicle under stable power operation conditions.

[0109] The working principle of the fuel cell system in the second control mode is as follows: Since the predicted power request change rate of the vehicle is less than or equal to the preset power request change rate, it indicates that the vehicle is in a stable power operation condition. Therefore, the current target power request value of the vehicle is determined directly based on the real-time acquired current power request value of the vehicle and the vehicle power change control strategy (such as ramp curve). Based on the correspondence between the current target power request value and the air compressor flow rate, and the correspondence between the current target power request value and the back pressure valve pressure, the target regulating flow rate of the air compressor and the target regulating pressure of the back pressure valve are determined respectively. Finally, the air compressor and the back pressure valve are adjusted according to the target regulating flow rate and the target regulating pressure to meet the power demand of the vehicle under stable power operation conditions.

[0110] It should be noted that the control method described in any embodiment of the present invention can be implemented by the main controller in the vehicle system control platform. Alternatively, the main controller can determine the magnitude of the predicted power request change rate and the preset power change rate, and trigger the pre-adjustment controller of the first control mode and the pre-adjustment controller of the second control mode respectively to implement the control operation of the two control modes. The specific control method adopted can be set according to the actual situation, and no specific limitation is made here.

[0111] Figure 3 This is a control state flowchart of a vehicle fuel cell system provided in an embodiment of the present invention. For example, refer to... Figure 3 The system acquires throttle position and road scene monitoring information, determines the vehicle's predicted power request based on this information, and calculates the rate of change of the predicted power request. It then determines whether the rate of change of the predicted power request exceeds a threshold (i.e., a preset power change rate). If it does, the system triggers a dynamic control mode (i.e., the first control mode); otherwise, it triggers a normal control mode. In dynamic control mode, the system triggers the pre-adjustment controller of the first control mode, looks up the slope of the ramp module based on the power request rate, and simultaneously controls the back pressure valve opening by multiplying the opening by a correction coefficient to accelerate the adjustment of the back pressure valve pressure. Finally, it determines whether the rate of change of the predicted power request is less than the threshold and its duration is greater than a preset time. If so, the control mode of the fuel cell system is switched to normal control mode (i.e., the second control mode).

[0112] Figure 4 This is a structural block diagram of a control device for a vehicle fuel cell system provided in an embodiment of the present invention. The present invention also provides a control device for a vehicle fuel cell system, see reference... Figure 4 The control device 100 of the vehicle fuel cell system includes: a predicted power request change rate acquisition module 10, used to acquire the predicted power request change rate of the vehicle; and a fuel cell system control mode determination module 20, used to determine the control mode of the fuel cell system based on the predicted power request change rate and a preset power change rate; if the predicted power request change rate is greater than the preset power change rate, the fuel cell system is controlled in a first control mode; otherwise, the fuel cell system is controlled in a second control mode.

[0113] The technical solution of this embodiment provides a control device for a vehicle fuel cell system. This control device includes: a predicted power request change rate acquisition module for acquiring the predicted power request change rate of the vehicle; and a fuel cell system control mode determination module for determining the control mode of the fuel cell system based on the predicted power request change rate and a preset power change rate. If the predicted power request change rate is greater than the preset power change rate, the fuel cell system is controlled in a first control mode; otherwise, the fuel cell system is controlled in a second control mode. Therefore, this device can achieve the following: it can rationally select the corresponding control mode for triggering the fuel cell system based on the predicted power request change rate and the preset power change rate of the vehicle. This allows for rapid load loading and meets the vehicle's power request. Especially under conditions of frequent power changes, the system can still achieve rapid power response and real-time following, thereby reducing reliance on the power battery and extending the service life of the battery and electric propulsion system.

[0114] Optionally, the fuel cell system includes at least an air compressor and a back pressure valve; the control mode determination module 20 of the fuel cell system includes:

[0115] A vehicle power change control strategy adjustment unit is used to adjust the vehicle power change control strategy according to the predicted power request change rate.

[0116] The first current target power request value determination unit is used to obtain the current power request value of the vehicle and determine the current target power request value in combination with the adjusted vehicle power change control strategy.

[0117] The first target regulating flow determination unit is used to determine the target regulating flow of the air compressor based on the correspondence between the current target power request value and the air compressor flow rate.

[0118] The second target regulating pressure determination unit is used to determine the target regulating pressure of the back pressure valve based on the correspondence between the current target power request value and the back pressure valve pressure.

[0119] The correction adjustment unit is used to add a preset correction coefficient to accelerate the back pressure valve pressure adjustment rate when adjusting the back pressure valve pressure according to the target adjustment pressure.

[0120] Optionally, the vehicle power change control strategy is to control the rate of change of vehicle power according to a ramp curve; the vehicle power change control strategy adjustment unit is also used to: adjust the slope of the ramp curve according to the predicted rate of change of power request and the correspondence between the predicted rate of change of power request and the slope of the ramp curve, so as to adjust the rate of change of vehicle power.

[0121] Optionally, the relationship between the predicted power request change rate and the slope of the ramp curve is as follows: the rate of change of the predicted power request is positively correlated with the change of the slope of the ramp curve.

[0122] Optionally, the current target power request value determination unit is further configured to: obtain the current power request value of the vehicle, and determine the current target power request value in combination with the slope-adjusted ramp curve.

[0123] Optionally, the correction adjustment unit is further configured to: multiply the opening of the back pressure valve by a correction coefficient when adjusting the back pressure valve opening according to the target adjustment pressure to adjust the back pressure valve pressure, so as to accelerate the pressure adjustment rate of the back pressure valve.

[0124] Optionally, the fuel cell system includes at least an air compressor and a back pressure valve; the control mode determination module 20 of the fuel cell system includes:

[0125] The second current target power request value determination unit is used to obtain the current power request value of the vehicle and determine the current target power request value according to the vehicle power change control strategy.

[0126] The second target regulating flow unit is used to determine the target regulating flow of the air compressor based on the correspondence between the current target power request value and the air compressor flow rate.

[0127] The second target regulating pressure unit is used to determine the target regulating pressure of the back pressure valve based on the correspondence between the current target power request value and the back pressure valve pressure.

[0128] Optionally, the vehicle power change control strategy is to control the rate of change of vehicle power according to a ramp curve; the second current target power request value determination unit is further used for:

[0129] Obtain the vehicle's current power request value and determine the current target power request value based on the ramp curve; where the slope of the ramp curve is a fixed value.

[0130] Optionally, the vehicle includes: an accelerator pedal and a map navigation system; the predicted power request change rate acquisition module 10 includes:

[0131] The predicted power request determination unit is used to obtain the predicted power request of the vehicle based on the opening of the accelerator pedal and the prediction of the map navigation system.

[0132] The current power request value acquisition unit is used to acquire the current power request value of the vehicle.

[0133] The predicted power request change rate obtaining unit is used to obtain the predicted power request change rate based on the vehicle's predicted power request and the current power request value.

[0134] It should be understood that the various forms of processes shown above can be used, with steps reordered, added, or deleted. For example, the steps described in this invention can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this invention can be achieved, and this is not limited herein.

[0135] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A control method for a vehicle fuel cell system, characterized in that, include: Obtain the predicted power request change rate of the vehicle; The control mode of the fuel cell system is determined based on the predicted power request change rate and the preset power change rate. If the predicted power request change rate is greater than the preset power change rate, the fuel cell system is controlled in the first control mode. Otherwise, the fuel cell system is controlled in the second control mode; The fuel cell system includes at least an air compressor and a back pressure valve; The control of the fuel cell system in the first control mode includes: The vehicle power change control strategy is adjusted according to the predicted power request change rate. Obtain the current power request value of the vehicle, and determine the current target power request value by combining it with the adjusted vehicle power change control strategy; The target regulating flow rate of the air compressor is determined based on the correspondence between the current target power request value and the air compressor flow rate; The target regulating pressure of the back pressure valve is determined based on the correspondence between the current target power request value and the back pressure valve pressure. When adjusting the back pressure valve pressure according to the target adjustment pressure, a preset correction coefficient is added to accelerate the back pressure valve pressure adjustment rate; The fuel cell system includes at least an air compressor and a back pressure valve; The control of the fuel cell system in the second control mode includes: Obtain the current power request value of the vehicle, and determine the current target power request value according to the vehicle power change control strategy; The target regulating flow rate of the air compressor is determined based on the correspondence between the current target power request value and the air compressor flow rate; The target regulating pressure of the back pressure valve is determined based on the correspondence between the current target power request value and the back pressure valve pressure. The vehicle power change control strategy is to control the rate of change of vehicle power according to a ramp curve.

2. The control method for a vehicle fuel cell system according to claim 1, characterized in that, The method of adjusting the vehicle power change control strategy according to the predicted power request change rate includes: The slope of the ramp curve is adjusted based on the predicted power request change rate and the correspondence between the predicted power request change rate and the slope of the ramp curve, so as to regulate the rate of change of vehicle power.

3. The control method for a vehicle fuel cell system according to claim 2, characterized in that, The relationship between the predicted power request change rate and the slope of the ramp curve is as follows: The rate of change of the predicted power request is positively correlated with the slope of the ramp curve.

4. The control method for a vehicle fuel cell system according to claim 2, characterized in that, The step of obtaining the current power request value of the vehicle and determining the current target power request value in conjunction with the adjusted vehicle power change control strategy includes: The current power request value of the vehicle is obtained, and the current target power request value is determined by combining it with the slope curve after slope adjustment.

5. The control method for a vehicle fuel cell system according to claim 1, characterized in that, When adjusting the back pressure valve pressure according to the target adjustment pressure, adding a preset correction coefficient to accelerate the back pressure valve pressure adjustment rate includes: When adjusting the back pressure valve opening according to the target adjustment pressure to adjust the back pressure valve pressure, the back pressure valve opening is multiplied by the correction coefficient to accelerate the pressure adjustment rate of the back pressure valve.

6. The control method for a vehicle fuel cell system according to claim 1, characterized in that, The step of obtaining the current power request value of the vehicle and determining the current target power request value according to the vehicle power change control strategy includes: The current power request value of the vehicle is obtained, and the current target power request value is determined according to the ramp curve; wherein the slope of the ramp curve is a fixed value.

7. The control method for a vehicle fuel cell system according to claim 1, characterized in that, The vehicle includes: an accelerator pedal and a map navigation system; The step of obtaining the predicted power request change rate of the vehicle includes: The predicted power request of the vehicle is obtained based on the accelerator pedal opening and the map navigation system prediction. Obtain the current power request value of the vehicle; The predicted power request change rate is obtained based on the vehicle's predicted power request and the current power request value.

8. A control device for a vehicle fuel cell system, characterized in that, A control method for performing a vehicle fuel cell system as described in any one of claims 1-7, comprising: A predicted power request change rate acquisition module is used to acquire the predicted power request change rate of the vehicle. A control mode determination module for a fuel cell system is used to determine the control mode of the fuel cell system based on the predicted power request change rate and the preset power change rate. If the predicted power request change rate is greater than the preset power change rate, the fuel cell system is controlled in the first control mode. Otherwise, the fuel cell system is controlled in the second control mode.

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