Energy management method for fuel cell vehicle and fuel cell vehicle

Abstract

The present application relates to the technical field of vehicles, and discloses an energy management method for a fuel cell vehicle and the fuel cell vehicle. The energy management method for the fuel cell vehicle needs to firstly judge whether an initial SOC value is less than an initial preset SOC value. If yes, a fuel cell engine is started; if no, the fuel cell engine is not started. Secondly, in a heavy load state, when a real-time SOC value is raised to a first preset SOC value and kept for a first preset time, the fuel cell engine is turned off, and when the real-time SOC value is reduced to a second preset SOC value and kept for a second preset time, the fuel cell engine is started. In a light load state, when the real-time SOC value is raised to a third preset SOC value, the fuel cell engine is turned off, and when the real-time SOC value is reduced to a fourth preset SOC value, the fuel cell engine is started. The differentiation between the light load and the heavy load and the combination of the SOC preset value and the preset time can reduce the start-stop times of the fuel cell, the probability of high-power work, and improve the service life.

Description

Technical Field

[0001] This invention relates to the field of vehicle technology, and in particular to an energy management method for fuel cell vehicles and a fuel cell vehicle. Background Technology

[0002] In the energy management methods of fuel cell vehicles, the power request is greatly affected by the vehicle load. Currently, power distribution is mainly based on the dynamic control of the power battery's SOC (State of Charge). This method can, to a certain extent, ensure that the power battery will not be overcharged or over-discharged, and can also meet the power demand to a certain extent. However, if the power battery's SOC fluctuates greatly, the fuel cell may operate at a high power and may frequently change loads or even frequently start and stop. This reduces the fuel cell's economy and affects its service life.

[0003] Therefore, there is an urgent need for an energy management method for fuel cell vehicles and for fuel cell vehicles in order to solve the above problems. Summary of the Invention

[0004] One objective of this invention is to provide an energy management method for fuel cell vehicles, which can solve the problem of accelerated system degradation caused by long-term operation of fuel cells under high power or variable load conditions, and improve the service life of fuel cells.

[0005] Based on the above concept, the technical solution adopted by this invention is as follows:

[0006] An energy management method for fuel cell vehicles, which controls the operation of the interconnected power battery and fuel cell engine in the fuel cell vehicle according to the total power demand of the fuel cell vehicle, the energy management method for fuel cell vehicles includes:

[0007] S0: In the power battery driving state, the initial SOC value Mc of the power battery is obtained, and it is determined whether the initial SOC value Mc is less than the initial preset SOC value M. If yes, the fuel cell engine is started; otherwise, the fuel cell engine is not started.

[0008] When a fuel cell vehicle is operating under heavy load, the following steps are performed:

[0009] S11: If the fuel cell engine starts, the real-time SOC value Ms of the power battery continues to be acquired, and when the real-time SOC value Ms rises to the first preset SOC value M1 and is maintained for the first preset time t1, the fuel cell engine is shut down, M1≥M;

[0010] S12: If the fuel cell engine is not started, the real-time SOC value Ms of the power battery continues to be acquired, and when the real-time SOC value Ms decreases to the second preset SOC value M2 and is maintained for the second preset time t2, the fuel cell engine is started, M2 < M.

[0011] When a fuel cell vehicle is operating under light load, the following steps are performed:

[0012] S21: If the fuel cell engine starts, the real-time SOC value Ms of the power battery continues to be acquired, and when the real-time SOC value Ms increases to the third preset SOC value M3, the fuel cell engine is shut down, M3≥M.

[0013] S22: If the fuel cell engine is not started, the real-time SOC value Ms of the power battery is continuously acquired, and when the real-time SOC value Ms decreases to the fourth preset SOC value M4, the fuel cell engine is started, where M4 < M.

[0014] Optionally, when the fuel cell vehicle is under heavy load, the operating power of the fuel cell engine is set to Pz, and when the fuel cell vehicle is under light load, the operating power of the fuel cell engine is set to Pq, where Pz > Pq.

[0015] Optionally, M1 > M > M2, M3 > M > M4.

[0016] Optionally, M1 = M3, M2 = M4.

[0017] Optionally, t1≥3min, t2≥3min.

[0018] Optionally, t1 = t2.

[0019] Another objective of this invention is to provide a fuel cell vehicle that can solve the problem of accelerated system degradation caused by long-term operation of fuel cells under high power or variable load conditions, thereby improving the service life of fuel cells.

[0020] Based on the above concept, the technical solution adopted by this invention is as follows:

[0021] The energy management method for fuel cell vehicles described above is applied.

[0022] Optionally, the fuel cell vehicle includes a vehicle controller, a fuel cell controller, a fuel cell engine, a power battery manager, a power battery, a drive motor controller, and a drive motor;

[0023] The vehicle controller is communicatively connected to the fuel cell controller, the power battery manager, and the drive motor controller, respectively, so that the drive motor controller can manage the drive motor according to the overall vehicle requirements of the fuel cell vehicle, the power battery manager can manage the power battery according to the overall vehicle requirements of the fuel cell vehicle, and the fuel cell controller can manage the fuel cell engine according to the overall vehicle requirements of the fuel cell vehicle.

[0024] Optionally, the fuel cell vehicle further includes an instrument panel electrically connected to the vehicle controller. The instrument panel is used to receive a load signal of the fuel cell vehicle, which indicates whether the fuel cell vehicle is in a heavy-load or light-load state.

[0025] Optionally, the vehicle controller is used to obtain the total power demand of the fuel cell vehicle based on the accelerator pedal opening and the gradeability of the fuel cell vehicle.

[0026] The beneficial effects of this invention are as follows:

[0027] The energy management method for fuel cell vehicles proposed in this invention first acquires the initial SOC value Mc of the power battery under power battery driving conditions, and determines whether the initial SOC value Mc is less than the initial preset SOC value M. If yes, the fuel cell engine is started; otherwise, the fuel cell engine is not started. Then, when the fuel cell vehicle is running under heavy load, the following steps are executed: S11: If the fuel cell engine is started, the real-time SOC value Ms of the power battery is acquired, and when the real-time SOC value Ms rises to the first preset SOC value M1 and is maintained for the first preset time t1, the fuel cell engine is shut down, M1≥M; S12: If the fuel cell engine is not started, the real-time SOC value Ms of the power battery is acquired, and when the real-time SOC value Ms drops to the second preset SOC value M2 and is maintained for the second preset time t2, the fuel cell engine is started, M2≤M. When the vehicle operates under light load, the following steps are executed: S21: If the fuel cell engine is started, the real-time SOC value Mc of the power battery continues to be acquired. When the real-time SOC value Mc rises to the third preset SOC value M3, the fuel cell engine is shut down, M3≥M; S22: If the fuel cell engine is not started, the real-time SOC value Mc of the power battery continues to be acquired. When the real-time SOC value Mc drops to the fourth preset SOC value M4, the fuel cell engine is started, M4≤M. This energy management method for fuel cell vehicles, by distinguishing between light and heavy load states of the fuel cell vehicle and combining the setting of preset SOC values ​​and preset times, can minimize the number of fuel cell start-stop cycles and the probability of high-power operation, thereby improving the service life of the fuel cell.

[0028] The fuel cell vehicle proposed in this invention, by applying the above-mentioned energy management method for fuel cell vehicles, can solve the problem of accelerated system degradation caused by long-term operation of fuel cells under high power or variable load conditions, and improve the service life of fuel cells. Attached Figure Description

[0029] Figure 1 This is a flowchart of the energy management method for fuel cell vehicles provided in an embodiment of the present invention;

[0030] Figure 2 This is a schematic diagram of the control system architecture for a fuel cell vehicle provided in an embodiment of the present invention. Detailed Implementation

[0031] To make the technical problems solved by the present invention, the technical solutions adopted, and the technical effects achieved clearer, the technical solutions of the present invention will be further described below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely for explaining the present invention and are not intended to limit the present invention. Furthermore, it should be noted that, for ease of description, only the parts related to the present invention are shown in the accompanying drawings, not all of them.

[0032] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0033] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0034] In the description of this embodiment, the terms "upper," "lower," "left," and "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. In addition, the terms "first" and "second" are used only for distinction in description and have no special meaning.

[0035] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0036] Fuel cell vehicles have two power sources: a fuel cell and a power battery. During operation, the vehicle controller allocates the operation of the fuel cell and the power battery based on the vehicle's load signal and the power battery's state of charge (SOC) value provided by the power battery manager. Since different loads result in varying power battery SOC values ​​and different fuel cell demands, the energy management method for fuel cell vehicles provided in this embodiment, while distinguishing between light and heavy loads, controls the operation of the interconnected power battery and fuel cell engine based on the total power demand of the fuel cell vehicle. This minimizes the number of start-stop cycles and the probability of the fuel cell operating at high power, thereby improving the fuel cell's lifespan.

[0037] Specifically, S0: Under the power battery driving state, the initial SOC value Mc of the power battery is obtained, and it is determined whether the initial SOC value Mc is less than the initial preset SOC value M. If yes, the fuel cell engine is started; otherwise, the fuel cell engine is not started.

[0038] When a fuel cell vehicle is operating under heavy load, the following steps are performed:

[0039] S11: If the fuel cell engine starts, continue to acquire the real-time SOC value Ms of the power battery, and when the real-time SOC value Ms rises to the first preset SOC value M1 and is maintained for the first preset time t1, shut down the fuel cell engine, M1≥M;

[0040] S12: If the fuel cell engine is not started, the real-time SOC value Ms of the power battery will continue to be acquired. When the real-time SOC value Ms drops to the second preset SOC value M2 and is maintained for the second preset time t2, the fuel cell engine will be started, where M2 < M.

[0041] When a fuel cell vehicle is operating under light load, the following steps are performed:

[0042] S21: If the fuel cell engine starts, continue to acquire the real-time SOC value Ms of the power battery, and when the real-time SOC value Ms increases to the third preset SOC value M3, shut down the fuel cell engine, M3≥M;

[0043] S22: If the fuel cell engine is not started, the real-time SOC value Ms of the power battery will continue to be acquired, and when the real-time SOC value Ms drops to the fourth preset SOC value M4, the fuel cell engine will be started, where M4 < M.

[0044] Preferably, t1 ≥ 3 min and t2 ≥ 3 min. Setting appropriate preset times can ensure the power requirements of the vehicle while avoiding frequent switching of the fuel cell, thus ensuring the economy and service life of the fuel cell.

[0045] Preferably, t1 = t2.

[0046] Furthermore, to meet the power requirements of fuel cell vehicles under different load conditions, that is, when the SOC of the power battery is low, the fuel cell engine can be requested to work at high power to replenish the SOC while driving the fuel cell vehicle, the energy management method for fuel cell vehicles provided in this embodiment sets the operating power of the fuel cell engine differently under heavy load and light load conditions. Under heavy load conditions, the operating power of the fuel cell engine is set to Pz, and under light load conditions, the operating power of the fuel cell engine is set to Pq, where Pz > Pq.

[0047] Preferably, Pz ≤ 100 kW and Pq ≤ 80 kW. Appropriate operating power ensures the vehicle's power requirements while preventing the fuel cell from operating under high power conditions for extended periods, thus minimizing its lifespan.

[0048] Furthermore, to further avoid frequent start-ups and shutdowns of the fuel cell engine and ensure the lifespan of the fuel cell, the following settings are implemented: M1 > M > M2. This means that under heavy load, the fuel cell engine can only be restarted when the real-time SOC value Ms of the power battery drops below the initial preset SOC value M and remains at that level for a second preset time t2. Conversely, the fuel cell engine can only be shut down when the real-time SOC value Ms of the power battery rises above the initial preset SOC value and remains at that level for a first preset time t1. Setting the first preset SOC value M1 to be greater than the initial preset SOC value M, the second preset SOC value M2 to be less than the preset SOC value M, and limiting the time each preset value is maintained under the corresponding conditions are all aimed at preventing frequent start-ups and shutdowns of the fuel cell engine.

[0049] Similarly, M3 > M > M4, meaning that under light load conditions, the fuel cell engine can only be restarted when the real-time SOC value Ms of the power battery drops below the initial preset SOC value M, and the fuel cell engine can only be shut down when the real-time SOC value Ms of the power battery rises above the initial preset SOC value.

[0050] Preferably, M1 = M3, M2 = M4.

[0051] Preferably, the initial preset value M, the first preset value M1, the second preset value M2, the third preset value M3, and the fourth preset value M4 are in the range of 69% < M < 71%, and 72% < M1 < 78%, 37% < M2 < 43%, 72% < M3 < 78%, and 37% < M4 < 43%.

[0052] Energy management methods for fuel cell vehicles (refer to) Figure 1 The process shown is executed, and the specific values ​​mentioned above are not fixed for different vehicle models and need to be fine-tuned according to the battery characteristics of different vehicle models. In this embodiment, M1 = 75%, M2 = 40%, M3 = 75%, M4 = 40%, t1 = t2 = 3min, Pz = 100kW, Pq = 80kW.

[0053] For heavy loads, the SOC (State of Charge) may change drastically, requiring the fuel cell engine to have a higher maximum power demand to meet the vehicle's requirements.

[0054] When the initial SOC value Mc > 70%, the fuel cell engine is not requested to start, and the power required by the vehicle is provided by the power battery. To avoid frequent power changes under heavy load conditions, the fuel cell engine can only be requested to start again after the real-time SOC value Ms drops to 40% for more than 3 minutes, and the maximum power requested by the fuel cell engine is 100 kW.

[0055] When the initial SOC value Mc < 70%, the fuel cell engine is requested to start, and the maximum power requested by the fuel cell engine is 100 kW. To avoid frequent power changes under heavy load conditions, the fuel cell engine can only be shut down after the real-time SOC value Ms rises to 75% and lasts for more than 3 minutes.

[0056] Under light load, the SOC change may be relatively gradual. The maximum requested power of the fuel cell engine can be appropriately reduced to decrease the high-power operation time of the fuel cell engine and enhance its durability.

[0057] When the initial SOC value Mc > 70%, the fuel cell engine is not requested to start, and the power required by the vehicle is provided by the power battery. The fuel cell engine can be requested to start again when the real-time SOC value Ms decreases to 40%, and the maximum power requested by the fuel cell engine is 80 kW.

[0058] When the initial SOC value Mc < 70%, the fuel cell engine is requested to start, and the maximum power requested by the fuel cell engine is 80 kW. The fuel cell engine can only be shut down when the real-time SOC value Ms rises to 75%.

[0059] The energy management method for vehicles provided in this embodiment can maximize the lifespan of the fuel cell system by optimizing the software model and control method without adding complex algorithms, without making significant changes to the fuel cell and vehicle hardware.

[0060] This embodiment also provides a fuel cell vehicle. By applying the energy management method of the fuel cell vehicle described above, the problem of accelerated system degradation caused by long-term operation of fuel cells under high power or variable load conditions can be solved, thereby improving the service life of fuel cells.

[0061] like Figure 2 As shown, optionally, the fuel cell vehicle includes a vehicle controller, a fuel cell controller, a power battery manager, a drive motor controller, a fuel cell engine, a power battery, and a drive motor. The vehicle controller is communicatively connected to the fuel cell controller, the power battery manager, and the drive motor controller. The fuel cell controller manages the fuel cell engine according to the vehicle's requirements, the power battery manager manages the power battery according to the vehicle's requirements, and the drive motor controller manages the drive motor according to the vehicle's requirements.

[0062] In practice, the fuel cell controller dynamically monitors the state of the fuel cell stack, while the power battery manager dynamically monitors the state of the power battery. Both are connected to the vehicle controller of the fuel cell vehicle via the CAN bus of the automotive network to receive or relay signals sent by the fuel cell controller and the power battery manager. During operation, the vehicle controller uses the aforementioned energy management method for fuel cell vehicles to optimally allocate energy between the fuel cell and the power battery. It should be noted that in this embodiment, the energy management method for fuel cell vehicles only specifies the "SOC condition," meaning that the SOC value of the power battery obtained by the power battery manager is fed back to the vehicle controller. The vehicle controller uses the "SOC condition" as one of the acquired operational information, combined with other operational information such as vehicle speed and environmental information, to manage and allocate energy between the fuel cell and the power battery of the fuel cell vehicle.

[0063] Fuel cell vehicles also include a DC / DC converter electrically connected to the fuel cell engine and the power battery. This converter allows for better control of the voltage or current of the fuel cell and the power battery, eliminating the need for their voltages to match the bus voltage. The power battery and fuel cell are also electrically connected to the drive motor controller via a high-voltage bus, enabling them to power the drive motor.

[0064] Optionally, the fuel cell vehicle also includes an instrument panel, which is electrically connected to the vehicle controller. The instrument panel receives the load signal of the fuel cell vehicle, indicating whether the fuel cell vehicle is in a heavy-load or light-load state. In practice, the driver can select a heavy-load or light-load button on the instrument panel according to the current load, so that the corresponding load signal is sent to the vehicle controller through the instrument panel. If no selection is made, the fuel cell vehicle is in a light-load state by default.

[0065] Optionally, the vehicle controller is also used to obtain the total power demand of the fuel cell vehicle based on the accelerator pedal opening and the gradient of the fuel cell vehicle, so that the fuel cell vehicle can specifically allocate the operation of the power battery and / or fuel cell according to the energy management method of the fuel cell vehicle, thereby meeting the total power demand of the fuel cell vehicle.

[0066] The above embodiments merely illustrate the basic principles and characteristics of the present invention. The present invention is not limited to the above embodiments. Various changes and modifications can be made to the present invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. An energy management method for fuel cell vehicles, characterized in that, The energy management method for the fuel cell vehicle includes controlling the operation of the interconnected power battery and fuel cell engine in the fuel cell vehicle according to the total power demand of the fuel cell vehicle. S0: In the power battery driving state, the initial SOC value Mc of the power battery is obtained, and it is determined whether the initial SOC value Mc is less than the initial preset SOC value M. If yes, the fuel cell engine is started; otherwise, the fuel cell engine is not started. When a fuel cell vehicle is operating under heavy load, the following steps are performed: S11: If the fuel cell engine starts, the real-time SOC value Ms of the power battery continues to be acquired, and when the real-time SOC value Ms rises to the first preset SOC value M1 and is maintained for the first preset time t1, the fuel cell engine is turned off, M1≥M, 69%<M<71%; S12: If the fuel cell engine is not started, the real-time SOC value Ms of the power battery continues to be acquired, and when the real-time SOC value Ms drops to the second preset SOC value M2 and is maintained for the second preset time t2, the fuel cell engine is started, M2 < M, 37% < M2 < 43%; When a fuel cell vehicle is operating under light load, the following steps are performed: S21: If the fuel cell engine starts, the real-time SOC value Ms of the power battery continues to be acquired, and when the real-time SOC value Ms increases to the third preset SOC value M3, the fuel cell engine is shut down, M3≥M. S22: If the fuel cell engine is not started, the real-time SOC value Ms of the power battery continues to be acquired, and when the real-time SOC value Ms drops to the fourth preset SOC value M4, the fuel cell engine is started, M4 < M, 37% < M4 < 43%.

2. The energy management method for fuel cell vehicles according to claim 1, characterized in that, When a fuel cell vehicle is under heavy load, the operating power of the fuel cell engine is set to Pz, and when the fuel cell vehicle is under light load, the operating power of the fuel cell engine is set to Pq, where Pz > Pq.

3. The energy management method for fuel cell vehicles according to claim 1, characterized in that, M1 > M > M2, M3 > M > M4.

4. The energy management method for fuel cell vehicles according to claim 3, characterized in that, M1=M3, M2=M4.

5. The energy management method for a fuel cell vehicle according to claim 1, characterized in that, t1≥3min, t2≥3min.

6. The energy management method for a fuel cell vehicle according to claim 5, characterized in that, t1=t2.

7. A fuel cell vehicle, characterized in that, The energy management method for fuel cell vehicles according to any one of claims 1-6.

8. The fuel cell vehicle according to claim 7, characterized in that, The fuel cell vehicle includes a vehicle controller, a fuel cell controller, a fuel cell engine, a power battery manager, a power battery, a drive motor controller, and a drive motor. The vehicle controller is communicatively connected to the fuel cell controller, the power battery manager, and the drive motor controller, respectively, so that the drive motor controller can manage the drive motor according to the overall vehicle requirements of the fuel cell vehicle, the power battery manager can manage the power battery according to the overall vehicle requirements of the fuel cell vehicle, and the fuel cell controller can manage the fuel cell engine according to the overall vehicle requirements of the fuel cell vehicle.

9. The fuel cell vehicle according to claim 8, characterized in that, The fuel cell vehicle also includes an instrument panel, which is electrically connected to the vehicle controller. The instrument panel is used to receive the load signal of the fuel cell vehicle, which indicates whether the fuel cell vehicle is in a heavy load or light load state.

10. The fuel cell vehicle according to claim 8, characterized in that, The vehicle controller is used to obtain the total power demand of the fuel cell vehicle based on the accelerator pedal opening and the gradient of the fuel cell vehicle.

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