Self-adaptive power distribution control method for extended-range fuel cell power system

Abstract

The invention discloses a self-adaptive power distribution control method of an extended-range fuel cell power system. The extended-range fuel cell power system comprises a fuel cell and other power sources. In the whole operation cycle, firstly entering a standby mode; in the standby mode, the system continuously monitors judgment conditions, under the condition that the first condition is met, the system enters an other power source direct drive mode, and in the mode, other power sources provide power for the vehicle; under the condition that the second condition is met, the system enters a gas-electricity direct drive mode, and in the mode, the fuel cell provides power for the vehicle; under the condition that the third condition is met, the system enters the gas-electricity direct drive amp; in the charging mode, the fuel cell charges other power sources while providing power for the vehicle; according to the control method, accurate power distribution can be carried out according to actual conditions, and it is ensured that cooperative work between the fuel cell and other power sources reaches the optimal state.

Description

Technical Field

[0001] The present invention relates to the technical field of fuel cells, and particularly to an adaptive power distribution control method for an extended-range fuel cell power system. Background Art

[0002] A fuel cell is a device that directly converts the chemical energy of a fuel into electrical energy. A hydrogen fuel cell has the advantages of high fuel energy conversion efficiency, low noise, and zero emissions, and can be widely applied to transportation means such as automobiles, airplanes, trains, etc. and fixed power stations.

[0003] In the prior art, the fuel cell subsystem and the power battery subsystem of a fuel cell power system are generally separated. It is necessary to externally send power battery information to the fuel cell subsystem, and at the same time, it is necessary to externally send a power (or current) demand to the fuel cell subsystem to achieve power response before there can be a power (or current) output. At the same time, when the power battery reaches a certain value under idle conditions, the fuel cell power system will frequently start and stop.

[0004] The existing fuel cell technology can only be applied to a vehicle system that can send power commands, and is not applicable to devices such as communication equipment and industrial vehicles under complex working conditions. For devices such as communication equipment and industrial vehicles under complex working conditions, only power (or current) is generally given, and a command cannot be directly given to the fuel cell system to control the power output of the fuel cell system, so that the fuel cell system cannot provide the power required by the device. At the same time, when the state of charge (SOC) of the power battery reaches a certain value, the fuel cell power system will shut down, and when the remaining capacity of the power battery drops to a certain value, the fuel cell power system will start up again, starting and stopping repeatedly, reducing the durability of the fuel cell.

[0005] Moreover, the characteristics of the above fuel cell power system result in that in the common working mode of an extended-range fuel cell, when the monomer voltage of the battery management system (BMS) is lower than a specific limit value, the BMS and the vehicle control unit (VCU) will send a start-up command to the fuel cell controller (FCU), and then the fuel cell will charge at a constant power. However, this working mode is relatively single and cannot fully meet the requirements of various complex working conditions.

[0006] In order to solve the above technical problems, the present invention proposes an improved adaptive power distribution control method for an extended-range fuel cell power system. Summary of the Invention

[0007] Aiming at the defects in the prior art, the purpose of the present invention is to provide an adaptive power distribution control method for an extended-range fuel cell power system, focusing on the control strategy of the power distribution method under different working conditions. Through in-depth research and innovation, it aims to provide a more efficient and reliable operation scheme for the extended-range fuel cell under various complex working conditions, so as to improve its overall performance and service life. Whether it is in the frequent start-stop working condition on urban roads or in the continuous high-speed driving working condition on highways, this control strategy can accurately distribute power according to the actual situation to ensure that the collaborative work between the fuel cell and other power source systems reaches the best state.

[0008] Specifically, the technical problem to be solved by the present invention is that in view of the above deficiencies in the prior art, the present invention provides an adaptive power distribution control method for an extended-range fuel cell power system, and the extended-range fuel cell power system includes a fuel cell and other power sources; During the operation cycle of the entire extended-range fuel cell power system, it first enters the standby mode; In the standby mode, the system continuously monitors the judgment conditions. When condition one is met, the system enters mode 1 - direct drive mode of other power sources. In this mode, other power sources provide power for the vehicle; When condition two is met, the system enters mode 2 - direct drive mode of fuel cell and electricity. In this mode, the fuel cell provides power for the vehicle; When condition three is met, the system enters mode 3 - direct drive & charging mode of fuel cell and electricity. In this mode, the fuel cell provides power for the vehicle while also charging other power sources.

[0009] Preferably, condition one is: Trigger condition: V 单 >V max ; Operation logic: P 其他动力源 =P 电机 ,V 单 >V max ,otherwise exit; where: V 单 : The single-cell voltage value of other power sources, V max : The upper limit range value of the set optimal working single-cell voltage of other power sources, P 电机 : The motor demand power. For simplicity of the control model, the vehicle power is simplified to the motor power, P 其他动力源 : The output power of other power sources.

[0010] Preferably, condition two is: Trigger condition: V 单 =Vmax ; Operating logic: P 燃料 = P 电机 , within a certain period of time, if P 电机 remains stably within a certain range, enter this mode, and exit when V 单 ≠ V max ; where: P 燃料 : Output power of the fuel cell.

[0011] Preferably, condition three is divided into two cases. For case one: condition three is: Trigger condition: V max ≥ V 单 ≥ V min ; Operating logic: (1) P 燃料 = P SOC , if Δ soc ≥ 0, it means P 燃料 ≥ P 电机 , until V 单 ≥ V max or SOC = 90%, then exit this mode and stop the machine; (2) P 燃料 = P SOC , if Δ soc ≤ 0, it means P 燃料 ≤ P 电机 , in this mode: When Δ p电机 is less than the limit value, P 燃料 = P 电机ave + P a , until V 单 ≥ V max or SOC = 90%, then exit this mode and stop the machine; When Δ p of the motor is greater than the limit value, P 燃料 = P 电机max + P a , until V 单 ≥ V max or SOC = 90%, then exit this mode and stop the machine; Where: SOC: The monomer voltage gradient or SOC gradient Map is set according to the highest efficiency curve of the fuel cell, V min : Set the lower limit range value of the optimal working monomer voltage of other power sources, P SOC : Output power of the monomer voltage gradient or SOC gradient Map, P 电机max : P within a certain period of time in this mode电机 Maximum power P 电机ave : P within a certain time in this mode 电机 Average power P a : The power compensation coefficient in this mode, obtained by querying the power compensation Map Δ p电机 : P 电机 The power change value within a certain time Δ soc : The change value of SOC within a certain time

[0012] Preferably, condition three is divided into two cases. For case two: condition three is Trigger condition: V 单 <V min ; Operation logic: P 燃料 =P 燃料额 , V 单 >V min And after lasting for a certain time, exit this mode and enter case one Among them, P 燃料额 : The output power of the fuel cell

[0013] Preferably, it also includes mode 4 - manual charging mode. When condition four is met, the system enters mode 4 - manual charging mode. In this mode, the user manually controls the charging operation; condition four is Trigger condition: SOC<100%; Operation logic: P 燃料 Is equal to the manually input power value or the preset power gradient switch switching request power value; When SOC = 100%, exit this mode and stop the machine

[0014] Preferably, the standby mode is used for the situation where SOC is relatively high and the whole vehicle is not started

[0015] Preferably, the shutdown mode is used for the fault shutdown mode, or in case of a fault or VCU requests an emergency shutdown in each mode, immediately jump out of this mode and enter the shutdown mode

[0016] Preferably, the other power source is a lithium battery [[ID=6'4]]

[0017] During the operation cycle of the entire range - extender fuel cell power system, first enter the standby mode. In the standby mode, the system continuously monitors and judges conditions, mainly based on the lithium - ion battery single - cell voltage or state of charge (SOC) to determine the next operation mode

[0018] When specific conditions are met, the system enters different operating modes in sequence. First, it may enter Mode 1 - Lithium-ion direct drive mode. In this mode, the lithium battery mainly provides power for the vehicle. Subsequently, if the conditions change, it may enter Mode 2 - Fuel cell direct drive mode, where the fuel cell directly drives the vehicle. Then, under specific circumstances, the system will enter Mode 3 - Fuel cell direct drive & charging mode. In this mode, the fuel cell not only drives the vehicle but also charges the lithium battery, and the working conditions are relatively complex. If there are special requirements, it may also enter Mode 4 - Manual charging mode, in which the charging operation can be manually controlled by the user.

[0019] After entering each mode, the system continuously monitors the operating conditions in their respective modes. For example, in Mode 1, if the voltage of a single lithium-ion battery is too low or other specific situations occur, the system will determine whether to enter the standby mode or the shutdown mode to ensure the safe and stable operation of the system. Similarly, in other modes, it will also judge whether to standby, shutdown, or enter the next mode according to the corresponding operating conditions. Such an operating mechanism enables the system to flexibly switch between different working states to adapt to various complex operating conditions and improve the reliability and stability of the system.

[0020] Compared with the prior art, the positive effects of the present invention are: 1. The entire operation logic control is dominated by the fuel cell controller (FCU). This design greatly reduces the relevant workload of the vehicle manufacturer in system control. The vehicle manufacturer no longer needs to invest a large amount of manpower and time in developing complex control logics, and thus can concentrate more resources on improving other key performances of the whole vehicle, such as optimizing the comfort and safety of the vehicle.

[0021] 2. It can effectively ensure the lifespan of the fuel cell. At the current stage, the cost of the fuel cell is relatively high. Extending its service life is crucial for reducing the cost of the whole vehicle. Through precise power distribution control, it is possible to avoid the fuel cell from overworking under inappropriate working conditions, reduce its losses, and thus significantly improve the reliability and durability of the fuel cell.

[0022] 3. It improves the stability and reliability of the system. Since the FCU uniformly controls the entire operation logic, it can better coordinate the work of each component and avoid system failures caused by the incoordination between different control units. At the same time, this centralized control method is also convenient for fault diagnosis and maintenance, improving the maintainability of the system.

[0023] 4. It enhances the performance of the whole vehicle. Through optimized power distribution control, it can adjust the output of the fuel cell and other power sources in real time according to the actual needs of the vehicle, ensuring that the vehicle can obtain sufficient power under various working conditions and improving key performance indicators such as the acceleration performance and cruising range of the whole vehicle.

[0024] 5. Adapt to different usage scenarios. It can automatically adjust the power distribution strategy according to different driving habits, road conditions, and load conditions, and can provide users with efficient and reliable power output whether in the frequent start-stop conditions on urban roads or in the long-distance driving conditions on highways. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is the control flow chart in the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0026] The following combines Figure 1 with the detailed description to further illustrate the present invention.

[0027] Currently, in the common operating mode of the range-extended fuel cell, when the voltage of a single cell in the battery management system (BMS) is lower than a specific limit value, the BMS and the vehicle control unit (VCU) will send a startup instruction to the fuel cell controller (FCU), and then the fuel cell will charge at a constant power. However, this operating mode is relatively single and cannot fully meet the requirements of various complex working conditions.

[0028] At the same time, the operating modes of the range-extended fuel cell are mainly divided into direct drive, direct drive / charging, and single charging. Among them, the working conditions of the direct drive / charging mode are extremely complex. In this mode, the quality of the control strategy has a crucial impact on the service life of the fuel cell and the performance of the fuel cell. For example, if the control strategy is improper, it may cause the fuel cell to overwork, thereby shortening its service life; while a reasonable control strategy can maximize the performance of the fuel cell while meeting the vehicle's power requirements.

[0029] In order to better cope with various complex working conditions and at the same time achieve the important goal of extending the service life of the fuel cell, through in-depth research and continuous exploration, the present invention proposes an innovative adaptive power distribution control method for a range-extended fuel cell power system.

[0030] The above control method mainly realizes the adaptive distribution of power through various control strategies such as the single - cell voltage gradient of the battery management system (BMS), the state - of - charge (SOC) gradient, and the motor power change. Among them, the BMS single - cell voltage gradient can reflect the voltage change of the battery single - cell under different working conditions. By real - time monitoring and analyzing it, important reference basis for power distribution can be provided. The SOC gradient can reflect the changing trend of the remaining battery power, which helps to reasonably adjust the power output ratio between the fuel cell and the battery. And the motor power change is directly related to the vehicle's power demand. According to the change of the motor power, the output power of the fuel cell can be adjusted in time to meet the power demand of the vehicle under different driving conditions.

[0031] By comprehensively applying the above - mentioned various control strategies, precise control and adaptive distribution of the fuel cell output power can be effectively achieved in the fuel cell controller (FCU). Integrating the power distribution function into the FCU control program, in this way, the whole vehicle only needs to issue a power request, and other functions such as state - of - charge (SOC) management and fuel cell system control are no longer required, thus greatly simplifying the architecture of the whole - vehicle control system and improving the operation efficiency and stability of the system. Under various different working conditions, this method can automatically adjust the power distribution scheme according to the actual situation, ensuring that the fuel cell works efficiently without excessive loss, thereby effectively extending the service life of the fuel cell and providing a strong guarantee for the reliable operation of the range - extended fuel - cell vehicle.

[0032] The adaptive power distribution control method of the range - extended fuel - cell power system in the present invention mainly has six operation modes: standby, lithium - battery direct drive, fuel - cell direct drive, fuel - cell direct drive & charging, manual charging, and shutdown. See Figure 1 , and the specific control logic is as follows: Mode 1: Standby Description: Mainly used for situations where the SOC is relatively high and the whole vehicle has not started.

[0033] Mode 2: Lithium - battery direct drive Description: Mainly used for situations where the lithium - battery power is relatively high.

[0034] Trigger condition: V 单 >V max .

[0035] Operating logic: P 锂电 =P 电机 ; V 单 >V max , otherwise exit.

[0036] Mode 3: Fuel - cell direct drive Description: Mainly used for situations of constant load and constant working conditions.

[0037] Trigger condition: V 单 =V max .

[0038] Operation logic: P 燃料 =P 电机 ; Within a certain period of time, when P 电机 remains stable within a certain range, enter this mode; when V 单 ≠V max , exit.

[0039] Mode 4: Fuel cell direct drive & charging Description: Mainly used for multi-condition operation, P 电机 is unstable.

[0040] (1) Trigger condition: V max ≥V 单 ≥V min .

[0041] Operation logic: P 燃料 =P SOC , if Δ soc ≥0, it means P 燃料 ≥P 电机 , until V 单 ≥V max or SOC = 90%, then exit this mode and stop the machine; P 燃料 =P SOC , if Δ soc ≤0, it means P 燃料 ≤P 电机 , in this mode: When Δ p the motor is less than the limit value, P 燃料 =P 电机ave +P a , until V 单 ≥V max or SOC = 90%, then exit this mode and stop the machine.

[0042] When Δ p the motor is greater than the limit value, P 燃料 =P 电机max +P a , until V 单 ≥V max or SOC = 90%, then exit this mode and stop the machine.

[0043] (2) Trigger condition: V 单 <V min .

[0044] Operation logic: P燃料 = P 燃料额 , V 单 > V min After a certain period of time, exit this mode and enter mode (1) in mode four.

[0045] Mode Five: Manual Charging Description: Mainly used for the manual charging mode.

[0046] Trigger condition: SOC < 100%.

[0047] Operating logic: P 燃料 Equals the manually input power value or the power gradient switch request power value preset; when SOC = 100%, exit this mode and shut down.

[0048] [[ID=2 three]]Mode Six: Shutdown Description: Mainly used for the fault shutdown mode.

[0049] In addition, in case of a fault or the VCU requests an emergency shutdown in each mode, immediately jump out of this mode and enter the shutdown mode.

[0050] Among them: SOC: The single - cell voltage gradient (SOC gradient) Map is set according to the highest efficiency curve of the fuel cell.

[0051] V 单 : The single - cell voltage value of the lithium battery.

[0052] V min : Set the lower limit range value of the optimal working single - cell voltage of the lithium battery.

[0053] V max : Set the upper limit range value of the optimal working single - cell voltage of the lithium battery.

[0054] P SOC : The output power of the single - cell voltage gradient (or SOC gradient) Map.

[0055] P 燃料 : The output power of the fuel cell.

[0056] P 燃料额 : The output power of the fuel cell.

[0057] P 电机 : The motor demand power; for the simplicity of the control model, the vehicle power is simplified to the motor power.

[0058] P 锂电 : The output power of the lithium battery.

[0059] P 电机max : The maximum power of P motor within a certain period of time in this mode.

[0060] P电机ave : The average power of the P motor within a certain period of time in this mode.

[0061] P a : The power compensation coefficient in this mode, obtained by querying the power compensation Map.

[0062] Δ p电机 : The power change value of the P motor within a certain period of time.

[0063] Δ soc : The change value of SOC within a certain period of time.

[0064] During the operation cycle of the entire system, it first enters the standby mode. In the standby mode, the system continuously monitors the judgment conditions and mainly determines the next operation mode based on the voltage or state of charge (SOC) of the lithium - ion battery monomer.

[0065] When specific conditions are met, the system enters different operation modes in sequence. First, it may enter the lithium - ion direct - drive mode. In this mode, the lithium - ion battery mainly provides power for the vehicle. Subsequently, if the conditions change, it may enter the fuel - cell direct - drive mode, where the fuel cell directly drives the vehicle. Then, under specific circumstances, the system will enter the fuel - cell direct - drive & charging mode, in which the fuel cell drives the vehicle while charging the lithium - ion battery, and the working conditions are relatively complex. If there are special requirements, it may also enter the manual charging mode, which can be manually controlled by the user for charging operations.

[0066] After entering each mode, the system continuously monitors the operation conditions in each mode. For example, in the lithium - ion direct - drive mode, if the voltage of the lithium - ion battery monomer is too low or other specific situations occur, the system will judge whether to enter the standby mode or the shutdown mode to ensure the safe and stable operation of the system. Similarly, in other modes, it will also judge whether to standby, shutdown or enter the next mode according to the corresponding operation conditions. Such an operation mechanism enables the system to flexibly switch between different working states to adapt to various complex operation conditions and improve the reliability and stability of the system.

[0067] It can be seen that the FCU in the present invention has a built - in fuel - cell adaptive power distribution mode, using many factors such as the voltage of a single lithium - ion battery, SOC and its change, motor power and power change, and fuel - cell efficiency as the switching conditions for operation modes; the fuel - cell power distribution has six control modes: standby, lithium - ion direct - drive, fuel - cell direct - drive, fuel - cell direct - drive and power generation, manual power generation, and shutdown, and can be switched between each mode.

[0068] Compared with the prior art, the positive effects of the present invention are: 1. The overall operation logic control is dominated by the Fuel Cell Controller (FCU). This design greatly reduces the relevant workload of the vehicle manufacturer in system control. The vehicle manufacturer no longer needs to invest a large amount of manpower and time in developing complex control logics, and thus can concentrate more resources on improving other key performances of the whole vehicle, such as optimizing vehicle comfort, safety, etc.

[0069] 2. It can effectively guarantee the lifespan of the fuel cell. At the current stage, the cost of the fuel cell is relatively high, and extending its service life is crucial for reducing the cost of the whole vehicle. Through precise power distribution control, it is possible to avoid the fuel cell from overworking under inappropriate operating conditions, reduce its losses, and thus significantly improve the reliability and durability of the fuel cell.

[0070] 3. It improves the stability and reliability of the system. Since the FCU uniformly controls the entire operation logic, it can better coordinate the work of each component and avoid system failures caused by the incoordination between different control units. At the same time, this centralized control method is also convenient for fault diagnosis and maintenance, improving the maintainability of the system.

[0071] 4. It enhances the performance of the whole vehicle. Through optimized power distribution control, it can adjust the output of the fuel cell and other power sources in real time according to the actual needs of the vehicle, ensuring that the vehicle can obtain sufficient power under various operating conditions and improving key performance indicators such as the acceleration performance and cruising range of the whole vehicle.

[0072] 5. It adapts to different usage scenarios. It can automatically adjust the power distribution strategy according to different driving habits, road conditions, and load conditions. Whether in the frequent start-stop conditions on urban roads or in the long-distance driving conditions on highways, it can provide users with efficient and reliable power output.

[0073] The above only reflects the preferred technical solutions of the present invention. Some possible changes made by those skilled in the art to some parts thereof all reflect the principles of the present invention and should fall within the technical scope of the present invention.

Claims

1. An adaptive power distribution control method for an extended-range fuel cell power system, characterized in that, The range-extended fuel cell power system includes a fuel cell and other power sources; During the entire operation cycle of the range-extended fuel cell power system, it first enters the standby mode; In the standby mode, the system continuously monitors the judgment conditions. When condition 1 is met, the system enters Mode 1 - direct drive mode of other power sources. In this mode, other power sources provide power for the vehicle; When condition 2 is met, the system enters Mode 2 - direct drive mode of fuel cell and electricity. In this mode, the fuel cell provides power for the vehicle; When condition 3 is met, the system enters Mode 3 - direct drive of fuel cell and electricity & charging mode. In this mode, the fuel cell provides power for the vehicle and also charges other power sources; 2. The adaptive power distribution control method of an extended-range fuel cell power system according to claim 1, wherein, The said condition 1 is: Trigger condition: V 单 > V max ; Operation logic: P 其他动力源 = P 电机 , V 单 > V max , otherwise exit; Wherein: V 单 : The single cell voltage value of other power sources, V max : Set the upper limit range value of the optimal working single-cell voltage of other power sources. P 电机 : Motor required power. Simplify the control model and simplify the vehicle power to motor power. P 其他动力源 : Output power of other power sources.

3. The adaptive power distribution control method for an extended-range fuel cell power system according to claim 2, characterized in that The said condition 2 is: Trigger condition: V 单 =V max ; Operation logic: P 燃料 = P 电机 , within a certain period of time, P 电机 continuously and stably stays within a certain range to enter this mode, and exits when V 单 ≠ V max ; where: P 燃料 : Output power of the fuel cell.

4. The adaptive power distribution control method for an extended-range fuel cell power system according to claim 3, wherein The said condition 3 is divided into two cases. For case 1: condition 3 is: Trigger condition: V max ≥V 单 ≥V min ; Operation logic: (1)P 燃料 =P SOC If Δ soc ≥0, it indicates that P 燃料 ≥P 电机 until V 单 ≥V max or SOC = 90%, then exit this mode and stop the machine; (2)P 燃料 =P SOC If Δ soc ≤ 0, it indicates that P 燃料 ≤ P 电机 In this mode: When Δ p电机 is less than the limit value, P 燃料 = P 电机ave + P a , until V 单 ≥ V max or SOC = 90%, then exit this mode and stop the machine; When Δ p the motor is greater than the limit value, P 燃料 =P 电机max +P a until V 单 ≥V max or SOC = 90%, then exit this mode and stop the machine; Wherein: SOC: The single-cell voltage gradient or SOC gradient Map is set according to the highest efficiency curve of the fuel cell; V min : Set the lower limit range value of the optimal working monomer voltage of other power sources, P SOC : Output power of the single-cell voltage gradient or SOC gradient Map P 电机max : The maximum power of P within a certain period of time in this mode 电机 ​ P 电机ave : The average power of P within a certain period of time in this mode 电机 ​ P a : The power compensation coefficient in this mode is obtained by querying the power compensation Map. Δ p电机 : P 电机 The power change value within a certain period of time Δ soc : The change value of SOC within a certain period of time.

5. The adaptive power distribution control method for an extended-range fuel cell power system according to claim 4, characterized in that, The said condition 3 is divided into two cases. For case 2: condition 3 is: Trigger condition: V 单 <V min ; Operation logic: P 燃料 = P 燃料额 , V 单 > V min After a certain period of time, exit this mode and enter Case 1; Among them, P 燃料额 : Output power of the fuel cell.

6. The adaptive power distribution control method for an extended-range fuel cell power system as described in claim 5, characterized in that, It also includes Mode 4 - manual charging mode. When condition 4 is met, the system enters Mode 4 - manual charging mode. In this mode, the user manually controls the charging operation; condition 4 is: Trigger condition: SOC < 100%; Operating logic: P 燃料 It is equal to the manually input power value or the requested power value for switching the preset power gradient switch; When SOC = 100%, exit this mode and stop the machine.

7. The adaptive power distribution control method for an extended-range fuel cell power system according to claim 6, characterized in that, The said standby mode is used for the situation where the SOC is relatively high and the whole vehicle has not been started.

8. The adaptive power distribution control method for an extended-range fuel cell power system according to claim 7, wherein The said shutdown mode is used for the fault shutdown mode, or when there is a fault or the VCU requests an emergency shutdown in each mode, it immediately jumps out of its mode and enters the shutdown mode.

9. The adaptive power distribution control method for an extended-range fuel cell power system as claimed in claims 1-8, characterized in that, The said other power source is a lithium battery.

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