A high-efficiency control method for a full-power fuel cell hybrid system

Abstract

The application discloses a kind of full-power fuel cell hybrid power system high-efficiency control method, belong to control technical field;Including the following steps: obtaining the current operating parameters of vehicle, and hydrogen fuel cell operating parameter, according to the demand information obtained, calculate the demand information of vehicle and hydrogen fuel cell operating information, and then determine the current operating state of vehicle and the current working state of hydrogen fuel cell;In different vehicle operating state, according to the calculated vehicle demand information and hydrogen fuel cell working state, determine whether to switch the working state of hydrogen fuel cell;According to the determination result, switch the working state of hydrogen fuel cell, so that hydrogen fuel cell works in the most efficient area.The application can make hydrogen fuel cell in the case of participating in work as far as possible in the best working area, so that the performance of hydrogen fuel cell is in higher area, effectively improves the overall efficiency of vehicle;Control strategy is simple, real-time good.

Description

Technical Field

[0001] This invention belongs to the field of control technology, specifically relating to a high-efficiency control method for a full-power fuel cell hybrid power system. Background Technology

[0002] Based on the power efficiency characteristics of hydrogen fuel cells, it can be seen that within a certain electrical density range during operation, the power and efficiency of hydrogen fuel cells are both relatively high. Therefore, operating within this range maximizes the advantages of hydrogen fuel cells, and this range is referred to as the optimal operating range in this invention patent. If a control method can be used to ensure that the hydrogen fuel cell in a vehicle operates within the optimal operating range as much as possible, the best energy consumption can be achieved. Current patents generally assume that the hydrogen fuel cell is constantly operating, idling when power output is not needed, and do not address the optimal operating range of the hydrogen fuel cell. CN113002370A provides a real-time energy management strategy based on vehicle speed prediction and minimizing equivalent hydrogen consumption, but does not address the operating range of the hydrogen fuel cell. CN 114523952A provides a driving method for a hybrid vehicle, but does not involve hydrogen fuel cell vehicles. CN 113173080A provides a driving mode switching method for hydrogen fuel cell vehicles, dividing the vehicle's operating state into positive torque mode, zero torque mode, and negative torque mode, but does not address the optimal operating range of the hydrogen fuel cell. This invention comprehensively considers the start-up and shutdown timing control of hydrogen fuel cells and aims to keep the hydrogen fuel cells within their optimal operating range as much as possible during operation, thereby maximizing the efficiency and performance of hydrogen fuel cells. Summary of the Invention

[0003] In view of the above-mentioned technical problems in the prior art, the present invention proposes a high-efficiency control method for a full-power fuel cell hybrid power system. The method is reasonably designed, overcomes the shortcomings of the prior art, and has good results.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] A high-efficiency control method for a full-power fuel cell hybrid power system includes the following steps:

[0006] Step S101: Obtain the current operating parameters of the vehicle and the operating parameters of the hydrogen fuel cell. Calculate the demand information of the vehicle and the operating information of the hydrogen fuel cell based on the obtained demand information, and then determine the current operating status of the vehicle and the current working status of the hydrogen fuel cell.

[0007] Step S102: Under different vehicle operating conditions, based on the vehicle demand information calculated in step S101 and the operating status of the hydrogen fuel cell, determine whether to switch the operating status of the hydrogen fuel cell.

[0008] Step S103: Based on the determination result, switch the working state of the hydrogen fuel cell so that the hydrogen fuel cell works in the most efficient region.

[0009] Preferably, the hybrid vehicle equipped with a hydrogen fuel cell has a power source including a hydrogen fuel cell and an auxiliary power source, wherein the auxiliary power source includes a power battery, a supercapacitor, and a flywheel battery.

[0010] Preferably, the vehicle's current operating parameters include: auxiliary power source SOC (State of charge) value, vehicle speed, current output power of hydrogen fuel cell, real-time accelerator pedal opening, and real-time brake pedal opening;

[0011] The current operating status of the vehicle includes: braking status, driving status, starting status, parking status, and coasting status;

[0012] The working states of a hydrogen fuel cell are divided into the hydrogen fuel cell shutdown mode, the hydrogen fuel cell start-up phase, the hydrogen fuel cell minimum power fixed-point output mode in the high-efficiency zone, the hydrogen fuel cell maximum power fixed-point output mode in the high-efficiency zone, the hydrogen fuel cell power following mode in the high-efficiency zone, and the hydrogen fuel cell power output mode in the low-efficiency zone.

[0013] The criteria for determining the switching of hydrogen fuel cell operating states under different vehicle operating conditions include the auxiliary power source SOC threshold and the required power threshold.

[0014] Preferably, in step S102, the method for determining the current operating status of the vehicle is as follows:

[0015] When the vehicle speed is 0 and the accelerator pedal is pressed, it is in the starting state;

[0016] When the vehicle speed is not 0 and the brake pedal is depressed, it is in braking mode;

[0017] When the vehicle speed is not 0 and the accelerator pedal is depressed, it is in driving mode;

[0018] When the vehicle speed is not 0 and neither the accelerator nor the brake pedal is depressed, it is in a coasting state.

[0019] When the vehicle speed is 0 and the accelerator pedal is not pressed, it is in a stopped state.

[0020] Preferably, in step S101, the method for calculating vehicle demand information is as follows:

[0021] Step S501: Obtain the drive pedal opening and brake pedal opening;

[0022] Step S502: Obtain the vehicle's required power by looking up the table according to the pedal MAP diagram. The vehicle's required power is the vehicle's demand information.

[0023] Preferably, when the vehicle is running, it is driven only by the auxiliary power source, and the hydrogen fuel cell is in shutdown mode;

[0024] The rules for switching the state of the hydrogen fuel cell while the vehicle is in motion are as follows:

[0025] When the vehicle is in driving mode, set the auxiliary power source SOC threshold to SOC. low SOC high and the required power threshold, where P low P high These represent the minimum and maximum values ​​of the high-efficiency region for hydrogen fuel cells, respectively.

[0026] The start-stop conditions for hydrogen fuel cells are set as follows:

[0027] (1) When the SOC value of the auxiliary power source is less than the set threshold SOC low Afterwards, the hydrogen fuel cell is switched out of the hydrogen fuel cell shutdown mode. At this time, the fuel cell is loaded at the set loading rate and switches to different working modes according to different power requirements.

[0028] (2) When the SOC value of the auxiliary power source is greater than the set threshold SOC high Then, the hydrogen fuel cell unloads at a set unloading rate until the output power is 0, and enters the hydrogen fuel cell shutdown mode.

[0029] The rules for switching the operating mode of the fuel cell are set as follows:

[0030] (1) Conditions for switching the lowest power fixed-point output mode in the high-efficiency region of hydrogen fuel cells

[0031] If the calculated power demand P req Less than the minimum power P in the high-efficiency region of hydrogen fuel cells low When the hydrogen fuel cell enters the lowest power fixed-point output mode in the high-efficiency region, as shown in equation (1);

[0032]

[0033] At this time, the hydrogen fuel cell power P fc With auxiliary power source power P bat They are respectively

[0034]

[0035] Among them, the auxiliary power source power P bat A negative value indicates that the battery is being charged;

[0036] (2) Hydrogen fuel cell power follower mode

[0037] When the required power is greater than the minimum power P in the high-efficiency region of the hydrogen fuel cell low When the vehicle enters the power follow mode, the hydrogen fuel cell will provide the power required by the vehicle. The power required by the vehicle will be provided by the auxiliary power source. In the power follow mode, a variety of energy management strategies and algorithms will be used to distribute the power between the hydrogen fuel cell and the auxiliary power source.

[0038] The switching logic is shown in equation (3):

[0039]

[0040] At this time, the output power of the hydrogen fuel cell and the auxiliary power source is as shown in equation (4):

[0041]

[0042] In the formula, P req' The calculated power of the hydrogen fuel cell for the energy management strategy;

[0043] (3) Highest power fixed-point output mode in the high-efficiency region of hydrogen fuel cell

[0044] When the power demand exceeds the highest power point P in the high-efficiency region of the hydrogen fuel cell high Furthermore, when the SOC value of the auxiliary power source is greater than the set SOC threshold of the auxiliary power source, the hydrogen fuel cell enters the highest power fixed-point output mode in the high-efficiency zone; at this time, the hydrogen fuel cell outputs power at the maximum power point in the high-efficiency zone.

[0045] The switching rules are shown in equation (5):

[0046]

[0047] At this time, the power output of the hydrogen fuel cell and the power output of the auxiliary power source are as shown in equation (6):

[0048]

[0049] (4) Hydrogen fuel cell non-efficient zone mode

[0050] When the power demand exceeds the highest power point P in the high-efficiency region of the hydrogen fuel cell high Furthermore, when the SOC value of the auxiliary power source is less than the set SOC threshold of the auxiliary power source, the hydrogen fuel cell enters the non-efficient output mode. At this time, the working conditions are relatively harsh, and the hydrogen fuel cell cannot only work in the efficient region, but uses the highest power output.

[0051] The switching rules are shown in equation (7):

[0052]

[0053] The power distribution between the fuel cell and the auxiliary power source is shown in equation (8):

[0054]

[0055] (5) Hydrogen fuel cell shutdown mode

[0056] When the auxiliary power source SOC value is greater than the set threshold SOC high Afterwards, the hydrogen fuel cell switched to shutdown mode.

[0057] Preferably, when the vehicle is in a coasting, braking, or stopped state, if the hydrogen fuel cell is in non-stop mode and the auxiliary power source SOC value is less than the threshold SOC... high When the hydrogen fuel cell is in non-shutdown mode and the auxiliary power source's SOC value is greater than the threshold SOC, the hydrogen fuel cell maintains its current operating mode and output power. high When the hydrogen fuel cell is in shutdown mode, it enters shutdown mode; if the hydrogen fuel cell is in shutdown mode, it will remain in this mode without switching.

[0058] The beneficial technical effects of this invention are as follows:

[0059] This invention enables hydrogen fuel cells to operate within their optimal operating range while in operation, maximizing their performance and effectively improving overall vehicle efficiency. The control strategy is simple, requiring minimal computation, and offers good real-time performance and engineering applicability. Attached Figure Description

[0060] Figure 1 This is a flowchart of the method of the present invention;

[0061] Figure 2 A flowchart for determining whether to switch the operating state of the hydrogen fuel cell;

[0062] Figure 3 A schematic diagram illustrating the optimal operating range for hydrogen fuel cells;

[0063] Figure 4 Flowchart for determining vehicle operating status;

[0064] Figure 5 A flowchart for calculating vehicle demand information;

[0065] Figure 6 This is a schematic diagram illustrating the state switching rules of a hydrogen fuel cell under vehicle driving conditions. Detailed Implementation

[0066] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments:

[0067] like Figure 1 As shown, a high-efficiency control method for a full-power fuel cell hybrid power system includes the following steps:

[0068] Step S101: Obtain the current operating parameters of the vehicle and the operating parameters of the hydrogen fuel cell. Calculate the demand information of the vehicle and the operating information of the hydrogen fuel cell based on the obtained demand information, and then determine the current operating status of the vehicle and the current working status of the hydrogen fuel cell.

[0069] Step S102: Under different vehicle operating states, based on the vehicle demand information calculated in step S101 and the operating state of the hydrogen fuel cell, determine whether to switch the operating state of the hydrogen fuel cell; the process is as follows: Figure 2 As shown;

[0070] Step S103: Based on the determination result, switch the working state of the hydrogen fuel cell so that the hydrogen fuel cell works in the most efficient region.

[0071] The method for setting the high-efficiency region of a hydrogen fuel cell is generated based on the power and efficiency characteristics of the hydrogen fuel cell, such as... Figure 3 As shown.

[0072] The vehicle's current operating parameters include: auxiliary power source SOC value, vehicle speed, current output power of the hydrogen fuel cell, real-time accelerator pedal opening, and real-time brake pedal opening;

[0073] The current operating status of the vehicle includes: braking status, driving status, starting status, parking status, and coasting status;

[0074] The working states of a hydrogen fuel cell are divided into hydrogen fuel cell shutdown mode, hydrogen fuel cell startup phase, hydrogen fuel cell minimum power fixed-point output mode in the high-efficiency zone, hydrogen fuel cell maximum power fixed-point output mode in the high-efficiency zone, hydrogen fuel cell power follow mode in the high-efficiency zone, and hydrogen fuel cell power output mode.

[0075] The criteria for determining the switching of hydrogen fuel cell operating states under different vehicle operating conditions include the auxiliary power source SOC threshold and the required power threshold.

[0076] In step S102, the method for determining the current operating status of the vehicle (its process is as follows) Figure 4 As shown below:

[0077] When the vehicle speed is 0 and the accelerator pedal is pressed, it is in the starting state;

[0078] When the vehicle speed is not 0 and the brake pedal is depressed, it is in braking mode;

[0079] When the vehicle speed is not 0 and the accelerator pedal is depressed, it is in driving mode;

[0080] When the vehicle speed is not 0 and neither the accelerator nor the brake pedal is depressed, it is in a coasting state.

[0081] When the vehicle speed is 0 and the accelerator pedal is not pressed, it is in a stopped state.

[0082] In step S101, the method for calculating vehicle demand information (its process is as follows) Figure 5 As shown below:

[0083] Step S501: Obtain the drive pedal opening and brake pedal opening;

[0084] Step S502: Obtain the vehicle's required power by looking up the table according to the pedal MAP diagram. The vehicle's required power is the vehicle's demand information.

[0085] When the vehicle is running, it is driven only by the auxiliary power source, and the hydrogen fuel cell is in shutdown mode;

[0086] Hydrogen fuel cell state switching rules under vehicle driving conditions (e.g.) Figure 6 As shown below:

[0087] When the vehicle is in driving mode, set the auxiliary power source SOC threshold to SOC. low SOC high and the required power threshold, where P low P high These represent the minimum and maximum values ​​of the high-efficiency region for hydrogen fuel cells, respectively.

[0088] The start-stop conditions for hydrogen fuel cells are set as follows:

[0089] (1) When the SOC value of the auxiliary power source is less than the set threshold SOC low Afterwards, the hydrogen fuel cell is switched out of the hydrogen fuel cell shutdown mode. At this time, the fuel cell is loaded at the set loading rate and switches to different working modes according to different power requirements.

[0090] (2) When the SOC value of the auxiliary power source is greater than the set threshold SOC high Then, the hydrogen fuel cell unloads at a set unloading rate until the output power is 0, and enters the hydrogen fuel cell shutdown mode.

[0091] The rules for switching the operating mode of the fuel cell are set as follows:

[0092] (1) Conditions for switching the lowest power fixed-point output mode in the high-efficiency region of hydrogen fuel cells

[0093] If the calculated power demand P reqLess than the minimum power P in the high-efficiency region of hydrogen fuel cells low When the hydrogen fuel cell enters the lowest power fixed-point output mode in the high-efficiency region, as shown in equation (1);

[0094]

[0095] At this time, the hydrogen fuel cell power P fc With auxiliary power source power P bat They are respectively

[0096]

[0097] Among them, the auxiliary power source power P bat A negative value indicates that the battery is being charged;

[0098] (2) Hydrogen fuel cell power follower mode

[0099] When the required power is greater than the minimum power P in the high-efficiency region of the hydrogen fuel cell low When the vehicle enters the power follow mode, the hydrogen fuel cell will provide the power required by the vehicle. The power required by the vehicle will be provided by the auxiliary power source. In the power follow mode, a variety of energy management strategies and algorithms will be used to distribute the power between the hydrogen fuel cell and the auxiliary power source.

[0100] The switching logic is shown in equation (3):

[0101]

[0102] At this time, the output power of the hydrogen fuel cell and the auxiliary power source is as shown in equation (4):

[0103]

[0104] In the formula, P req' The calculated power of the hydrogen fuel cell for the energy management strategy;

[0105] (3) Highest power fixed-point output mode in the high-efficiency region of hydrogen fuel cell

[0106] When the power demand exceeds the highest power point P in the high-efficiency region of the hydrogen fuel cell high Furthermore, when the SOC value of the auxiliary power source is greater than the set SOC threshold of the auxiliary power source, the hydrogen fuel cell enters the highest power fixed-point output mode in the high-efficiency zone; at this time, the hydrogen fuel cell outputs power at the maximum power point in the high-efficiency zone.

[0107] The switching rules are shown in equation (5):

[0108]

[0109] At this time, the power output of the hydrogen fuel cell and the power output of the auxiliary power source are as shown in equation (6):

[0110]

[0111] (4) Hydrogen fuel cell non-efficient zone mode

[0112] When the power demand exceeds the highest power point P in the high-efficiency region of the hydrogen fuel cell high Furthermore, when the SOC value of the auxiliary power source is less than the set SOC threshold of the auxiliary power source, the hydrogen fuel cell enters the non-efficient output mode. At this time, the working conditions are relatively harsh, and the hydrogen fuel cell cannot only work in the efficient region, but uses the highest power output.

[0113] The switching rules are shown in equation (7):

[0114]

[0115] The power distribution between the fuel cell and the auxiliary power source is shown in equation (8):

[0116]

[0117] (5) Hydrogen fuel cell shutdown mode

[0118] When the auxiliary power source SOC value is greater than the set threshold SOC high Afterwards, the hydrogen fuel cell switched to shutdown mode.

[0119] When the vehicle is coasting, braking, or stationary, if the hydrogen fuel cell is in non-stop mode and the auxiliary power source SOC value is less than the threshold SOC... high When the hydrogen fuel cell is in non-shutdown mode and the auxiliary power source's SOC value is greater than the threshold SOC, the hydrogen fuel cell maintains its current operating mode and output power. high When the hydrogen fuel cell is in shutdown mode, it enters shutdown mode; if the hydrogen fuel cell is in shutdown mode, it will remain in this mode without switching.

[0120] Of course, the above description is not intended to limit the present invention, and the present invention is not limited to the examples given above. Any changes, modifications, additions or substitutions made by those skilled in the art within the scope of the present invention should also fall within the protection scope of the present invention.

Claims

1. A high-efficiency control method for a full-power fuel cell hybrid power system, characterized in that: Includes the following steps: Step S101: Obtain the current operating parameters of the vehicle and the operating parameters of the hydrogen fuel cell. Calculate the demand information of the vehicle and the operating information of the hydrogen fuel cell based on the obtained demand information, and then determine the current operating status of the vehicle and the current working status of the hydrogen fuel cell. Step S102: Under different vehicle operating conditions, based on the vehicle demand information calculated in step S101 and the operating status of the hydrogen fuel cell, determine whether to switch the operating status of the hydrogen fuel cell. Step S103: Based on the determination result, switch the working state of the hydrogen fuel cell so that the hydrogen fuel cell works in the most efficient region; The vehicle's current operating parameters include: auxiliary power source SOC value, vehicle speed, current output power of the hydrogen fuel cell, real-time accelerator pedal opening, and real-time brake pedal opening; The current operating status of the vehicle includes: braking status, driving status, starting status, parking status, and coasting status; The working states of a hydrogen fuel cell are divided into the hydrogen fuel cell shutdown mode, the hydrogen fuel cell start-up phase, the hydrogen fuel cell minimum power fixed-point output mode in the high-efficiency zone, the hydrogen fuel cell maximum power fixed-point output mode in the high-efficiency zone, the hydrogen fuel cell power following mode in the high-efficiency zone, and the hydrogen fuel cell power output mode in the low-efficiency zone. The criteria for determining the switching of hydrogen fuel cell operating states under different vehicle operating conditions include the auxiliary power source SOC threshold and the required power threshold. When the vehicle is running, it is driven only by the auxiliary power source, and the hydrogen fuel cell is in shutdown mode; The rules for switching the state of the hydrogen fuel cell while the vehicle is in motion are as follows: When the vehicle is in driving mode, the auxiliary power source SOC threshold is set to... and the required power threshold, where These represent the minimum and maximum values ​​of the high-efficiency region for hydrogen fuel cells, respectively. The start-stop conditions for hydrogen fuel cells are set as follows: (1) When the SOC value of the auxiliary power source is less than the set threshold Afterwards, the hydrogen fuel cell is switched out of the hydrogen fuel cell shutdown mode. At this time, the fuel cell is loaded at the set loading rate and switches to different working modes according to different power requirements. (2) When the SOC value of the auxiliary power source is greater than the set threshold Then, the hydrogen fuel cell unloads at a set unloading rate until the output power is 0, and enters the hydrogen fuel cell shutdown mode. The rules for switching the operating mode of the fuel cell are set as follows: (1) Switching conditions for the lowest power fixed-point output mode in the high-efficiency region of hydrogen fuel cells If the calculated power demand Less than the minimum power of the high-efficiency region of hydrogen fuel cells When the hydrogen fuel cell enters the lowest power fixed-point output mode in the high-efficiency region, as shown in equation (1); （1）； At this time, the hydrogen fuel cell power With auxiliary power source power They are respectively （2）； Among them, the auxiliary power source power A negative value indicates that the battery is being charged; (2) Hydrogen fuel cell power follower mode When the power demand exceeds the minimum power in the high-efficiency region of the hydrogen fuel cell When the vehicle enters the power follow mode, the hydrogen fuel cell will provide the power required by the vehicle. The power required by the vehicle will be provided by the auxiliary power source. In the power follow mode, a variety of energy management strategies and algorithms will be used to distribute the power between the hydrogen fuel cell and the auxiliary power source. The switching logic is shown in equation (3): （3）； At this time, the output power of the hydrogen fuel cell and the auxiliary power source is as shown in equation (4): （4）； In the formula, The calculated power of the hydrogen fuel cell for the energy management strategy; (3) Highest power fixed-point output mode in the high-efficiency region of hydrogen fuel cell When the power demand exceeds the highest power point of the high-efficiency region of the hydrogen fuel cell Furthermore, when the SOC value of the auxiliary power source is greater than the set SOC threshold of the auxiliary power source, the hydrogen fuel cell enters the highest power fixed-point output mode in the high-efficiency zone; at this time, the hydrogen fuel cell outputs power at the maximum power point in the high-efficiency zone. The switching rules are shown in equation (5): （5）； At this time, the power output of the hydrogen fuel cell and the power output of the auxiliary power source are as shown in equation (6): （6）； (4) Non-efficient region mode of hydrogen fuel cell When the power demand exceeds the highest power point of the high-efficiency region of the hydrogen fuel cell Furthermore, when the SOC value of the auxiliary power source is less than the set SOC threshold of the auxiliary power source, the hydrogen fuel cell enters the non-efficient output mode. At this time, the working conditions are relatively harsh, and the hydrogen fuel cell cannot only work in the efficient region, but uses the highest power output. The switching rules are shown in equation (7): （7）； The power distribution between the fuel cell and the auxiliary power source is shown in equation (8): （8）； (5) Hydrogen fuel cell shutdown mode When the auxiliary power source SOC value is greater than the set threshold Afterwards, the hydrogen fuel cell switched to shutdown mode.

2. The high-efficiency control method for a full-power fuel cell hybrid power system according to claim 1, characterized in that: Hybrid vehicles equipped with hydrogen fuel cells have a power source consisting of a hydrogen fuel cell and an auxiliary power source, which includes a power battery, a supercapacitor, and a flywheel battery.

3. The high-efficiency control method for a full-power fuel cell hybrid power system according to claim 1, characterized in that: In step S102, the method for determining the current operating status of the vehicle is as follows: When the vehicle speed is 0 and the accelerator pedal is pressed, it is in the starting state; When the vehicle speed is not 0 and the brake pedal is depressed, it is in braking mode; When the vehicle speed is not 0 and the accelerator pedal is depressed, it is in driving mode; When the vehicle speed is not 0 and neither the accelerator nor the brake pedal is depressed, it is in a coasting state. When the vehicle speed is 0 and the accelerator pedal is not pressed, it is in a stopped state.

4. The high-efficiency control method for a full-power fuel cell hybrid power system according to claim 1, characterized in that: In step S101, the method for calculating vehicle demand information is as follows: Step S501: Obtain the drive pedal opening and brake pedal opening; Step S502: Obtain the vehicle's required power by looking up the table according to the pedal MAP diagram. The vehicle's required power is the vehicle's demand information.

5. The high-efficiency control method for a full-power fuel cell hybrid power system according to claim 1, characterized in that: When the vehicle is coasting, braking, or stationary, if the hydrogen fuel cell is in non-stop mode and the auxiliary power source SOC value is less than the threshold... When the hydrogen fuel cell is in non-shutdown mode and the auxiliary power source's SOC value is greater than the threshold, the hydrogen fuel cell maintains its current operating mode and output power, and the generated electricity is used to charge the battery. When the hydrogen fuel cell is in shutdown mode, it enters shutdown mode; if the hydrogen fuel cell is in shutdown mode, it will remain in this mode without switching.

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