Fuel cell load-up control method, device and vehicle

Abstract

The application relates to the technical field of vehicles, in particular to a fuel cell loading control method and device and a vehicle, wherein the method comprises the following steps: receiving a vehicle power request; calculating a vehicle power request increase value of a fuel cell system within a first preset time length according to the vehicle power request; matching an optimal air metering ratio of an air compressor of the fuel cell system according to the vehicle power request increase value within the first preset time length, and controlling the air compressor to supply air to the fuel cell system based on the optimal air metering ratio. According to the fuel cell loading control method, the problem that the efficiency of the fuel cell system is reduced and the double waste of the electric pile and other energy storage devices occurs by increasing the capacity of other energy storage devices in the prior art can be solved, the damage of the electric pile caused by oxygen starvation can be effectively avoided, and the oxygen flow required by the chemical reaction of the electric pile can be ensured.

Description

Technical Field

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

[0002] The lifespan of a fuel cell is highly dependent on its cathode-side air supply, which is provided by an air compressor.

[0003] In related technologies, when a sharp power ramp-up request occurs, the fuel cell system is typically prevented from responding to the rapid power increase by limiting the power ramp-up slope. The difference between the requested power and the stack output power is provided by the power battery or supercapacitor.

[0004] However, because fuel cell systems cannot respond quickly to sharp power ramp-up requests, the only solution is to increase the capacity of other energy storage devices. Furthermore, fuel cell systems cannot maximize their power output for the entire vehicle, resulting in a double waste of the fuel cell stack and other energy storage devices, which urgently needs to be addressed. Summary of the Invention

[0005] In view of this, the present invention aims to propose a load control method for fuel cells. This method solves the problem in related technologies that increasing the capacity of other energy storage devices not only reduces the efficiency of the fuel cell system but also results in double waste of the fuel cell stack and other energy storage devices. It ensures sufficient air supply to the fuel cell stack during rapid load changes, avoids insufficient air flow and air pressure fluctuations when switching air compressor modes, effectively avoids fuel cell stack damage caused by oxygen starvation, and ensures the oxygen flow required for the chemical reaction of the fuel cell stack.

[0006] To achieve the above objectives, the technical solution of the present invention is implemented as follows:

[0007] A method for controlling the load increase of a fuel cell includes the following steps:

[0008] Receive the vehicle's total power request;

[0009] Calculate the increase in the vehicle power request of the fuel cell system within a first preset time period based on the vehicle power request; and

[0010] The optimal air metering ratio of the air compressor of the fuel cell system is matched according to the increase in the vehicle power request within the first preset time period, and the air compressor is controlled to supply air to the fuel cell system based on the optimal air metering ratio.

[0011] Furthermore, before matching the optimal air metering ratio of the air compressor of the fuel cell system according to the increase in the vehicle power request within the first preset time period, the method further includes:

[0012] Obtain the actual power of the fuel cell system;

[0013] Calculate the first difference between the requested value of the vehicle power request and the actual power;

[0014] When the first difference is greater than the first preset threshold and the increase in vehicle power request within the first preset time period is greater than the second preset threshold, the air compressor is controlled to enter the boost working mode; otherwise, the normal working mode is maintained.

[0015] Furthermore, the air metering ratio in the boosted operating mode is higher than that in the normal operating mode.

[0016] Furthermore, the air metering ratio of the boost working mode is a preset air metering ratio or is obtained by matching the increase in vehicle power request value within the first preset time period.

[0017] Furthermore, after controlling the air compressor to enter the boost pressure operating mode, the following is also included:

[0018] The current power of the fuel cell system is detected, and a second difference between the requested value of the vehicle power request and the current power is calculated.

[0019] When the second difference is less than or equal to the first preset threshold and the duration is greater than the second preset duration, the air compressor is controlled to switch from the boosting working mode to the normal working mode.

[0020] Compared with existing technologies, the fuel cell load control method of the present invention has the following advantages:

[0021] The fuel cell load control method of the present invention can calculate the increase in the vehicle power request of the fuel cell system within a first preset time period based on the received vehicle power request, and match the optimal air metering ratio of the air compressor of the fuel cell system according to the increase in the vehicle power request of the fuel cell system within the first preset time period. Thus, air is supplied to the fuel cell system based on the optimal air metering ratio. This solves the problem in related technologies where increasing the capacity of other energy storage devices not only reduces the efficiency of the fuel cell system, but also results in double waste of the fuel cell stack and other energy storage devices. It ensures sufficient air supply to the fuel cell stack during rapid load changes, avoids insufficient air flow and air pressure fluctuations when switching air compressor modes, effectively avoids fuel cell stack damage caused by oxygen starvation, and ensures the oxygen flow required for the chemical reaction of the fuel cell stack.

[0022] Another objective of this invention is to provide a fuel cell load control device that solves the problem in related technologies where increasing the capacity of other energy storage devices not only reduces the efficiency of the fuel cell system but also results in a double waste of the fuel cell stack and other energy storage devices. This device can effectively avoid fuel cell stack damage caused by oxygen starvation and ensure the oxygen flow required for the fuel cell stack chemical reaction.

[0023] To achieve the above objectives, the technical solution of the present invention is implemented as follows:

[0024] A load control device for a fuel cell includes:

[0025] The receiving module is used to receive the vehicle's total power request.

[0026] The calculation module is used to calculate the increase in the vehicle power request of the fuel cell system within a first preset time period based on the vehicle power request; and

[0027] The control module is used to match the optimal air metering ratio of the air compressor of the fuel cell system according to the increase value of the vehicle power request within the first preset time period, and control the air compressor to supply air to the fuel cell system based on the optimal air metering ratio.

[0028] Furthermore, before matching the optimal air metering ratio of the air compressor of the fuel cell system according to the increase in the vehicle power request within the first preset time period, the control module is also configured to:

[0029] Obtain the actual power of the fuel cell system;

[0030] Calculate the first difference between the requested value of the vehicle power request and the actual power;

[0031] When the first difference is greater than the first preset threshold and the increase in power request within the first preset time period is greater than the second preset threshold, the air compressor is controlled to enter the boost working mode; otherwise, the normal working mode is maintained.

[0032] Furthermore, the air metering ratio in the boosted operating mode is higher than that in the normal operating mode.

[0033] Furthermore, the air metering ratio of the boost working mode is a preset air metering ratio or is obtained by matching the increase in vehicle power request value within the first preset time period.

[0034] Furthermore, after controlling the air compressor to enter the boost pressure operating mode, the control module is also used to:

[0035] The current power of the fuel cell system is detected, and a second difference between the requested value of the vehicle power request and the current power is calculated.

[0036] When the second difference is less than or equal to the first preset threshold and the duration is greater than the second preset duration, the air compressor is controlled to switch from the boosting working mode to the normal working mode.

[0037] The fuel cell load control device described above has the same advantages over the prior art as the fuel cell load control method described above, and will not be repeated here.

[0038] Another objective of this invention is to provide a vehicle that solves the problem in related technologies where increasing the capacity of other energy storage devices not only reduces the efficiency of the fuel cell system but also results in a double waste of the fuel cell stack and other energy storage devices. This vehicle can effectively avoid fuel cell stack damage caused by oxygen starvation and ensure the oxygen flow required for the fuel cell stack chemical reaction.

[0039] To achieve the above objectives, the technical solution of the present invention is implemented as follows:

[0040] A vehicle is provided with a fuel cell load control device as described in the above embodiments.

[0041] The vehicle described above has the same advantages over the prior art as the fuel cell load control device mentioned above, and will not be repeated here. Attached Figure Description

[0042] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0043] Figure 1 This is a flowchart of a fuel cell load control method according to an embodiment of the present invention;

[0044] Figure 2 This is a flowchart of a fuel cell load control method according to an embodiment of the present invention;

[0045] Figure 3 This is a block diagram of a fuel cell load control device according to an embodiment of the present invention. Detailed Implementation

[0046] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0047] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0048] Figure 1 This is a flowchart of a fuel cell load control method according to an embodiment of the present invention.

[0049] like Figure 1 As shown, the fuel cell load control method according to an embodiment of the present invention includes the following steps:

[0050] Step S101: Receive the vehicle's total power request.

[0051] In this embodiment of the application, the vehicle power request can be received through the fuel cell system controller.

[0052] Step S102: Calculate the increase in vehicle power request of the fuel cell system within a first preset time period based on the vehicle power request.

[0053] The first preset duration can be a duration set by the user, a duration obtained through a limited number of experiments, or a duration obtained through a limited number of computer simulations; no specific limitation is made here.

[0054] Specifically, in this embodiment of the application, the duration from time a to time b is taken as the first preset duration, such as 20 seconds. In this embodiment of the application, the vehicle power request increase value within the first preset duration can be obtained by subtracting the vehicle power request value at time a from the vehicle power request value at time b.

[0055] Step S103: Match the optimal air metering ratio of the air compressor of the fuel cell system with the increase value of the vehicle power request within the first preset time period, and control the air compressor to supply air to the fuel cell system based on the optimal air metering ratio.

[0056] Each vehicle power request increase within a first preset time period can be set with a corresponding optimal air metering ratio, or a corresponding optimal air metering ratio can be set based on the range of vehicle power request increase within the first preset time period. The corresponding optimal air metering ratio can be a user-preset air metering ratio, an air metering ratio obtained through a limited number of experiments, or an air metering ratio obtained through a limited number of computer simulations. No specific limitation is made here. The value of the optimal air metering ratio is also related to the fuel cell voltage and the actual bearing capacity of each component during rapid load changes.

[0057] It should be understood that the lifespan of a fuel cell is highly dependent on its cathode-side air supply, which is provided by an air compressor. Furthermore, during stack operation, the air compressor provides an air flow rate with a metering ratio greater than 1 to the stack, effectively protecting it from oxygen starvation and ensuring the oxygen flow required for the stack's chemical reactions.

[0058] Therefore, after calculating the increase in vehicle power demand within the first preset time period, this embodiment of the application can match the optimal air metering ratio of the air compressor in the fuel cell system according to the fuel cell voltage and the capacity of each component (such as the air compressor), thereby supplying air to the fuel cell system based on the optimal air metering ratio. It should be noted that the method of supplying air to the fuel cell system based on the optimal air metering ratio is the same as the control method in related technologies, and will not be described in detail here to avoid redundancy.

[0059] Therefore, based on the received vehicle power request, the increase in vehicle power request within a first preset time period is calculated, and the optimal air metering ratio of the air compressor of the fuel cell system is matched according to the increase in vehicle power request within the first preset time period. Thus, air is supplied to the fuel cell system based on the optimal air metering ratio. This solves the problem in related technologies where increasing the capacity of other energy storage devices not only reduces the efficiency of the fuel cell system but also results in a double waste of the fuel cell stack and other energy storage devices. It can effectively avoid fuel cell stack damage caused by oxygen starvation and ensure the oxygen flow required for the chemical reaction of the fuel cell stack.

[0060] Furthermore, in some embodiments, before matching the optimal air metering ratio of the air compressor of the fuel cell system according to the increase in the vehicle power request within a first preset time period, the method further includes: obtaining the actual power of the fuel cell system; calculating a first difference between the requested value of the vehicle power request and the actual power; and controlling the air compressor to enter a boost working mode when the first difference is greater than a first preset threshold and the increase in the vehicle power request within the first preset time period is greater than a second preset threshold, otherwise maintaining the normal working mode.

[0061] Furthermore, in some embodiments, the air metering ratio in the boosted operating mode is higher than that in the normal operating mode.

[0062] Furthermore, in some embodiments, the air metering ratio in the boost mode is a preset air metering ratio or is obtained by matching the increase in vehicle power request value within a first preset time period.

[0063] The first and second preset thresholds can both be user-defined thresholds, thresholds obtained through a limited number of experiments, or thresholds obtained through a limited number of computer simulations. The preset air metering ratio can also be user-defined air metering ratios, air metering ratios obtained through a limited number of experiments, or air metering ratios obtained through a limited number of computer simulations. No specific limitation is made here. The air metering ratio in normal operating mode is the metering ratio during steady-state operation of the fuel cell stack. Preferably, the first preset threshold can be a small value, such as 0.5 kW or 1 kW, and the second preset threshold can be 10 kW.

[0064] Specifically, this application embodiment can obtain the actual power of the current fuel cell system. By comparing the obtained actual power of the fuel cell system with the request value of the vehicle power request received by the fuel cell system controller, and calculating a first difference between the request value of the vehicle power request and the actual power of the fuel cell system, if the first difference between the request value of the vehicle power request and the actual power of the fuel cell system is greater than a first preset threshold, and the increase value of the vehicle power request within a first preset time period is greater than a second preset threshold, it indicates that the power request is increasing sharply. This application embodiment can control the vehicle to enter the boost working mode. At this time, the air metering ratio will be set higher than the metering ratio during the steady-state operation of the fuel cell stack. This air metering ratio can be a preset air metering ratio or obtained by matching the increase value of the vehicle power request within a first preset time period, without specific limitation here. If the first difference between the request value of the vehicle power request and the actual power of the fuel cell system is less than or equal to the first preset threshold, or the increase value of the vehicle power request within a first preset time period is less than or equal to the second preset threshold, it indicates that there is no sharp increase in the power request. This application embodiment can control the air compressor to supply air to the fuel cell system based on the metering ratio during the steady-state operation of the fuel cell stack.

[0065] Furthermore, in some embodiments, after controlling the air compressor to enter the boost working mode, the method further includes: detecting the current power of the fuel cell system and calculating a second difference between the requested value of the vehicle power request and the current power; when the second difference is less than or equal to a first preset threshold and the duration is greater than a second preset duration, controlling the air compressor to switch from the boost working mode to the normal working mode.

[0066] It should be understood that if the air compressor is in boost mode for a long time, there will be certain problems, such as reducing the life of the air compressor. Therefore, after controlling the air compressor to enter boost mode, the embodiments of this application can detect the current power of the fuel cell system. If the second difference between the requested power of the vehicle and the current power of the fuel cell system is less than or equal to the first preset threshold and the duration is greater than the second preset duration (e.g., the second preset duration is 0.1s), the air compressor is controlled to switch from boost mode to normal operation mode, that is, the air compressor is controlled to supply air to the fuel cell system based on the metering ratio during the steady-state operation of the fuel cell stack.

[0067] To enable those skilled in the art to further understand the fuel cell load control method of the embodiments of this application, a detailed description is provided below with reference to specific embodiments.

[0068] like Figure 2 As shown, the fuel cell load control method includes the following steps:

[0069] S201, Begin.

[0070] S202, the fuel cell system controller receives the vehicle's power request.

[0071] S203, determine whether the first difference between the requested value of the vehicle power request and the actual power is greater than the first preset threshold, and whether the increase value of the vehicle power request within the first preset time period is greater than the second preset threshold. If yes, proceed to step S204; otherwise, proceed to step S207.

[0072] S204 controls the air compressor to enter the boost mode.

[0073] S205, determine whether the second difference between the requested value of the vehicle power request and the current power of the fuel cell system is less than or equal to the first preset threshold. If yes, proceed to step S206; otherwise, proceed to step S204.

[0074] S206, control the air compressor to switch from boosting working mode to normal working mode, and jump to execute step S208.

[0075] S207 controls the air compressor to maintain normal operating mode.

[0076] S208, End.

[0077] In summary, when the increase in vehicle power request within the first preset time period exceeds a certain value, and the difference between the requested vehicle power and the actual power exceeds a certain value, the fuel cell system controller will determine that the power request has increased sharply. This will cause the air compressor to enter boost mode (i.e., pressure ramp-up mode), and the air metering ratio will be set higher than the metering ratio during steady-state operation of the fuel cell stack, for example, 1.5 higher than the steady-state metering ratio. In boost mode, the air compressor responds faster, and the fuel cell stack output power climbs more quickly. When the fuel cell stack power climbs to a value that is a certain threshold away from the requested value for a certain period of time, such as 0.1 seconds (i.e., the difference between the requested vehicle power and the current power is less than or equal to a certain value), the air compressor mode will then be set to normal mode (i.e., normal operating mode). The transition of the air compressor control mode from boost mode to normal operating mode is smooth, improving the load ramp of the fuel cell system and making the control transition before and after load ramping relatively smooth, avoiding pressure overshoot and a sharp decrease in cathode airflow.

[0078] According to the fuel cell load control method of the present invention, the increase in the total vehicle power request of the fuel cell system within a first preset time period is calculated based on the received total vehicle power request of the vehicle, and the optimal air metering ratio of the air compressor of the fuel cell system is matched according to the increase in the total vehicle power request within the first preset time period. Thus, air is supplied to the fuel cell system based on the optimal air metering ratio. This solves the problem in related technologies where increasing the capacity of other energy storage devices not only reduces the efficiency of the fuel cell system but also results in double waste of the fuel cell stack and other energy storage devices. It ensures sufficient air supply to the fuel cell stack during rapid load changes, avoids insufficient air flow and air pressure fluctuations when switching air compressor modes, effectively avoids fuel cell stack damage caused by oxygen starvation, and ensures the oxygen flow required for the chemical reaction of the fuel cell stack.

[0079] Furthermore, such as Figure 3 As shown, an embodiment of the present invention also discloses a fuel cell load control device 10, which includes: a receiving module 100, a computing module 200 and a control module 300.

[0080] The receiving module 100 is used to receive the vehicle's total power request.

[0081] The calculation module 200 is used to calculate the increase in the vehicle power request of the fuel cell system within a first preset time period based on the vehicle power request.

[0082] The control module 300 is used to match the optimal air metering ratio of the air compressor of the fuel cell system according to the increase value of the vehicle power request within a first preset time period, and control the air compressor to supply air to the fuel cell system based on the optimal air metering ratio.

[0083] Furthermore, before matching the optimal air metering ratio of the fuel cell system's air compressor based on the increase in the vehicle power request within a first preset time period, the control module 300 is also used to:

[0084] Obtain the actual power of the fuel cell system;

[0085] Calculate the first difference between the requested value of the vehicle power request and the actual power;

[0086] When the first difference is greater than the first preset threshold and the increase in vehicle power request within the first preset time period is greater than the second preset threshold, the air compressor is controlled to enter the boost working mode; otherwise, the normal working mode is maintained.

[0087] Furthermore, the air metering ratio in the boosted operating mode is higher than that in the normal operating mode.

[0088] Furthermore, the air metering ratio in the boost mode is either a preset air metering ratio or obtained by matching the power request increment.

[0089] Furthermore, after controlling the air compressor to enter the booster operating mode, the control module 300 is also used for:

[0090] The current power of the fuel cell system is detected, and a second difference between the requested value of the vehicle power request and the current power is calculated.

[0091] When the second difference is less than or equal to the second preset threshold and the duration is greater than the second preset duration, the air compressor is controlled to switch from the boosting working mode to the normal working mode.

[0092] It should be noted that the specific implementation of the fuel cell load control device in this embodiment of the invention is similar to the specific implementation of the fuel cell load control method. To reduce redundancy, it will not be described in detail here.

[0093] According to an embodiment of the present invention, the fuel cell load control device calculates the increase in the total vehicle power request of the fuel cell system within a first preset time period based on the received total vehicle power request, and matches the optimal air metering ratio of the air compressor of the fuel cell system based on the increase in the total vehicle power request within the first preset time period. This allows for air supply to the fuel cell system based on the optimal air metering ratio, solving the problem in related technologies where increasing the capacity of other energy storage devices not only reduces the efficiency of the fuel cell system but also results in double waste of the fuel cell stack and other energy storage devices. This ensures sufficient air supply to the fuel cell stack during rapid load changes, avoids insufficient airflow and air pressure fluctuations when switching air compressor modes, effectively prevents fuel cell stack damage caused by oxygen starvation, and guarantees the oxygen flow required for the chemical reaction of the fuel cell stack.

[0094] Furthermore, an embodiment of the present invention discloses a vehicle equipped with the fuel cell load control device described in the above embodiment. Because this vehicle has the aforementioned device, it solves the problem in related technologies where increasing the capacity of other energy storage devices not only reduces the efficiency of the fuel cell system but also results in a double waste of the fuel cell stack and other energy storage devices. It ensures sufficient air supply to the fuel cell stack during rapid load changes, avoids insufficient airflow and air pressure fluctuations when switching air compressor modes, effectively prevents fuel cell stack damage caused by oxygen starvation, and guarantees the oxygen flow required for the fuel cell stack's chemical reactions.

[0095] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for controlling the load increase of a fuel cell, characterized in that, Includes the following steps: Receive the vehicle's total power request; The increase in vehicle power request of the fuel cell system within a first preset time period is calculated based on the vehicle power request, wherein the increase in vehicle power request is the difference between the vehicle power request value at the end time and the start time of the first preset time period; Obtain the actual power of the fuel cell system; Calculate the first difference between the requested value of the vehicle power request and the actual power; When the first difference is greater than the first preset threshold and the increase in vehicle power request within the first preset time period is greater than the second preset threshold, the air compressor is controlled to enter the boost working mode; otherwise, the normal working mode is maintained. The air metering ratio of the boost working mode is higher than that of the normal working mode. as well as The optimal air metering ratio of the air compressor of the fuel cell system is matched according to the increase in the vehicle power request within the first preset time period, and the air compressor is controlled to supply air to the fuel cell system based on the optimal air metering ratio. After controlling the air compressor to enter the boost pressure working mode, the following is also included: The current power of the fuel cell system is detected, and a second difference between the requested value of the vehicle power request and the current power is calculated. When the second difference is less than or equal to the first preset threshold and the duration is greater than the second preset duration, the air compressor is controlled to switch from the boosting working mode to the normal working mode.

2. The method according to claim 1, characterized in that, The air metering ratio in the boost working mode is a preset air metering ratio or is obtained by matching the increase in vehicle power request value within the first preset time period.

3. A load control device for a fuel cell, characterized in that, The apparatus for implementing the fuel cell load control method as described in claim 1 or 2, the apparatus comprising: The receiving module is used to receive the vehicle's total power request. The calculation module is used to calculate the increase in the vehicle power request of the fuel cell system within a first preset time period based on the vehicle power request, wherein the increase in the vehicle power request is the difference between the vehicle power request value at the end time and the start time of the first preset time period; and The control module is used to match the optimal air metering ratio of the air compressor of the fuel cell system according to the increase value of the vehicle power request within the first preset time period, and control the air compressor to supply air to the fuel cell system based on the optimal air metering ratio. Before matching the optimal air metering ratio of the air compressor of the fuel cell system with the increase in vehicle power request within the first preset time period, the control module is further configured to: Obtain the actual power of the fuel cell system; Calculate the first difference between the requested value of the vehicle power request and the actual power; When the first difference is greater than the first preset threshold and the increase in power request is greater than the second preset threshold within the first preset time period, the air compressor is controlled to enter the boost working mode; otherwise, the normal working mode is maintained. The air metering ratio in the boost working mode is higher than the air metering ratio in the normal working mode.

4. The apparatus according to claim 3, characterized in that, The air metering ratio in the boost working mode is a preset air metering ratio or is obtained by matching the increase in vehicle power request value within the first preset time period.

5. A vehicle, characterized in that, include: The load control device for a fuel cell as described in claim 3 or 4.

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