A method for distributing overall power of a hydrogen fuel cell vehicle

Abstract

The present invention discloses a method for distributing the overall power of a hydrogen fuel cell vehicle. The control strategy of the present invention utilizes the rapid response of the power battery, with the power battery as the main output and the fuel-electric engine as the auxiliary output, and corrects the fuel-electric engine power by obtaining the power battery SOC (battery charge), continuous charging current, and maximum power demand. The stable operation of the fuel-electric engine is ensured, the fuel-electric engine operates in the high-efficiency zone, the fuel consumption is reduced, and the life of the fuel-electric engine is effectively extended. The power battery is kept in the high-efficiency zone, the fluctuation is reduced, and the life of the power battery is also effectively extended.

Description

Technical Field

[0001] The present invention relates to the technical field of new energy vehicles, and in particular to an overall power distribution method for a hydrogen fuel cell vehicle. Background Art

[0002] Based on the control strategy of ensuring the power performance of hydrogen fuel buses, as much regenerative braking as possible, preventing the power battery from overcharging and over-discharging, and ensuring smooth discharge of the fuel-electric system, the fuel-electric controller (FCU) needs to continuously receive the power battery SOC (battery charge) and current vehicle power sent by the vehicle. As these two quantities change, the fuel-electric controller (FCU) needs to continuously adjust the power generation power of the fuel-electric engine.

[0003] With the development of fuel-electric engines and the increase in the number of hydrogen fuel vehicles, road traffic conditions have become increasingly complex, requiring consideration of the smooth operation of fuel-electric engines, the overall fuel consumption rate of hydrogen fuel vehicles, and the need to avoid safety issues caused by overcharging and over-discharging of power batteries. Energy management of hydrogen fuel vehicles is a core and difficult issue in vehicle control, and there is no good solution for such complex and changeable road conditions.

[0004] The current control strategy allows the fuel-electric engine to operate at several specific power points, while the SOC of the power battery fluctuates greatly, accelerating the life decay of the power battery. In addition, the fuel-electric engine is frequently started and stopped, reducing its service life.

[0005] For example, the invention with publication number CN112572170A discloses a control method for a hydrogen fuel cell engine, the method comprising: obtaining the working state of the load end; when the working state of the load end is on, determining the power distribution of the load end, wherein the power distribution of the load end is the percentage of the load end in the total power generation of the hydrogen fuel cell engine; and controlling the operation of the hydrogen fuel cell engine based on the power distribution of the load end.

[0006] For another example, the invention with publication number CN109334476A provides a new fuel cell vehicle control system and control method. A fuel cell controller is added to the existing fuel cell vehicle control system. The vehicle controller controls the start and stop status of the fuel cell engine through the fuel cell controller. When the fuel cell engine is started, the target power is selected from the pre-set minimum power in the high-efficiency zone, maximum power in the high-efficiency zone and maximum available power according to the remaining power of the power battery and the vehicle speed; the target power is limited according to the operating conditions of the vehicle, thereby controlling the power output of the fuel cell engine. Summary of the invention

[0007] In view of the above-mentioned deficiencies in the prior art, the present invention provides a method for distributing overall power of a hydrogen fuel cell vehicle.

[0008] A method for distributing overall power of a hydrogen fuel cell vehicle. A hydrogen fuel cell vehicle includes a fuel-electric engine for generating electricity using hydrogen fuel, a power battery for power supply and energy storage, a main motor for driving the vehicle and energy recovery during braking, and other electrical components in the vehicle collectively referred to as vehicle accessories. The parameters are defined as follows:

[0009] DP_FC: rated power of the fuel-electric engine;

[0010] P_FC1: power at the high economic efficiency point of the fuel-electric engine;

[0011] Power battery SOC: power battery charge, the value is the ratio of remaining capacity to rated capacity;

[0012] Power battery SOC high efficiency zone: indicates that the power battery power is within this range, and the power battery output efficiency is high. L Indicates the lower limit of the power battery SOC high efficiency zone, with SOC H Indicates the upper limit of the power battery SOC high efficiency zone. H and SOC L Three points are selected as auxiliary points for power calibration, and the values ​​of the three points are SOC1, SOC2, and SOC3 from large to small;

[0013] SOC MAX : Power battery SOC safety upper limit, the value is greater than SOC H , less than 100%;

[0014] SOC MIN : Power battery SOC safety lower limit, the value is less than SOC L , greater than 0%;

[0015] Speed ​​threshold V S : The driving speed threshold of the vehicle;

[0016] P1: average power of the vehicle in normal operation;

[0017] P2: average power of the vehicle when running at high speed, uphill or at full load;

[0018] When the vehicle is in EV mode, the fuel-electric engine is not started. When the vehicle is in FC mode, the power distribution strategy is as follows:

[0019] (1) Power battery SOC>SOC H The fuel-electric engine does not start;

[0020] (2) Power battery SOC L <SOC<SOC H When the vehicle speed is greater than or equal to VS and when the allowable charging power of the power battery > 20% DP_FC, the fuel cell engine starts;

[0021] (3) When the SOC of the power battery < SOC L and the allowable charging power of the power battery > 10% DP_FC, the fuel cell engine starts when the vehicle starts in D gear;

[0022] (4) The output power range of the fuel cell engine is 20% DP_FC to 80% DP_FC;

[0023] (5) When the SOC of the power battery is between the SOC high-efficiency regions, the SOC maintenance strategy is adopted, and the real-time value of the output power of the fuel cell engine does not exceed the current allowable charging power of the power battery;

[0024] (6) When the power battery SOC1 ≤ SOC < SOC H , the output power of the fuel cell engine is P1;

[0025] (7) When the power battery SOC2 ≤ SOC < SOC1, the output power of the fuel cell engine is P_FC1;

[0026] (8) When the power battery SOC3 ≤ SOC < SOC2, the output power of the fuel cell engine is P2;

[0027] (9) When the power battery SOC MIN ≤ SOC < SOC3, the output power of the fuel cell engine is 90% DP_FC;

[0028] (10) When the power battery SOC < SOC MIN , the output power of the fuel cell engine is DP_FC;

[0029] (11) When any of the following conditions is met, the fuel cell engine shuts down:

[0030] (a) When the power battery SOC > SOC MAX ,

[0031] (b) When the allowable charging power of the power battery < 20% DP_FC,

[0032] (c) When switching to the OFF gear, EV mode or when the VCU requests shutdown using the key.

[0033] Preferably, the value of P_FC1 is taken as 70% DP_FC. The lower limit value SOC of the high-efficiency region of the power battery SOC L is 40%, and the upper limit value SOC of the high-efficiency region of the power battery SOC H is 80%. SOC1 is taken as 70%, SOC2 is taken as 60%, and SOC3 is taken as 50%. SOC MAX is taken as 80% - 90%. SOCMIN Take 20-30%.

[0034] Preferably, the operating condition database used to obtain P1 selects the NYCC operating condition or UDDS operating condition representing the urban operating condition or the suburban operating condition respectively; the operating condition database used to obtain P2 selects the HWFET operating condition representing the highway operating condition. Among them, the P1 obtained by the NYCC operating condition and the UDDS operating condition representing the urban operating condition and the suburban operating condition respectively is relatively close.

[0035] Preferably, P1 is 50% DP_FC-70% DP_FC, and P2 is 60% DP_FC-80% DP_FC.

[0036] Preferably, in point (5), when the power battery adopts the SOC maintenance strategy, the fuel-electric engine changes linearly between 20% DP_FC and 70% DP_FC.

[0037] EV mode: Pure electric mode, that is, the vehicle operates only with energy supplied by the power battery.

[0038] FC mode: fuel-electric engine hybrid mode, that is, the vehicle is powered by a fuel cell and a power battery.

[0039] The control strategy of the present invention utilizes the rapid response of the power battery, with the power battery as the main output and the fuel-electric engine as the auxiliary output, and corrects the fuel-electric engine power by obtaining the power battery SOC (battery charge), continuous charging current, and maximum power demand.

[0040] Firstly, this method ensures the power performance of hydrogen fuel buses and solves the core difficulties in vehicle control.

[0041] Secondly, this method improves the feedback energy, and the fuel-electric engine operates in a high-efficiency area, which reduces the overall fuel consumption of the hydrogen fuel bus.

[0042] Thirdly, this method takes into account the safety issues caused by overcharging and over-discharging of power batteries, ensuring the safety of power batteries for hydrogen fuel cells.

[0043] The smooth operation of the fuel-electric engine is ensured. The fuel-electric engine runs in the high-efficiency zone, which reduces fuel consumption and effectively extends the life of the fuel-electric engine. The power battery remains in the high-efficiency zone, fluctuations are reduced, and the life of the power battery is also effectively extended. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 This is a schematic diagram of the circuit connection structure of a hydrogen fuel cell vehicle.

[0045] Figure 2This is a graph showing the relationship between fuel-electric engine power and efficiency (%).

[0046] Figure 3 This is a curve of the power battery SOC changing with time in the NYCC operating condition simulation data when the initial SOC is 60%.

[0047] Figure 4 This is a graph showing the power variation of the fuel-electric engine over time in the NYCC operating condition simulation data when the initial SOC is 60%.

[0048] Figure 5 This is a curve of the power battery SOC changing with time in the NYCC operating condition simulation data when the initial SOC is 30%.

[0049] Figure 6 This is a graph showing the power variation of the fuel-electric engine over time in the NYCC operating condition simulation data when the initial SOC is 30%.

[0050] Figure 7 This is a curve of the power battery SOC changing with time in the NYCC operating condition simulation data when the initial SOC is 90%.

[0051] Figure 8 This is a graph showing the power variation of the fuel-electric engine over time in the NYCC operating condition simulation data when the initial SOC is 90%.

[0052] Fig. 9 This is a graph showing how the power of a fuel-electric engine changes over time in measured data.

[0053] Fig.10 This is a graph showing the relationship between the fuel-electric engine power and the power battery SOC in Comparative Example 1.

[0054] Fig.11 This is a curve chart of the power battery SOC changing with time in the simulation data of comparative example 1.

[0055] Fig.12 This is a curve chart of the fuel-electric engine power changing over time in the simulation data of comparative example 1. DETAILED DESCRIPTION

[0056] like Figure 1As shown, hydrogen fuel cell vehicles include a fuel-electric engine for hydrogen fuel power generation, a power battery for power supply and energy storage, a main motor for vehicle driving and energy recovery during braking, and other electrical components in the vehicle, collectively referred to as vehicle accessories. All relevant components are incorporated into the vehicle power supply network, wherein the fuel-electric engine generates power and is then boosted by DC / DC and then incorporated into the vehicle power supply network; the power battery can be charged by the fuel-electric engine on the one hand, and by the electric energy generated by energy recovery during braking on the second hand, and can supply power to the main motor and vehicle accessories on the third hand; the main motor can be powered by the vehicle power supply network through DC / AC when driving, and can reversely supplement the vehicle power supply network with electric energy when recovering braking energy.

[0057] The overall strategy of the overall power distribution method of hydrogen fuel cell vehicles in this application is as follows:

[0058] Define the parameters as follows:

[0059] DP_FC: rated power of the fuel-electric engine.

[0060] P_FC1: The power at the high economic efficiency point of the fuel-electric engine.

[0061] Power battery SOC: Power battery charge, the value is the ratio of remaining capacity to rated capacity.

[0062] Power battery SOC high efficiency zone: indicates that the power battery power is within this range, and the power battery output efficiency is high. L Indicates the lower limit of the power battery SOC high efficiency zone, with SOC H Indicates the upper limit of the power battery SOC high efficiency zone. H and SOC L Three points are selected as auxiliary points for power calibration, and the values ​​of the three points are SOC1, SOC2, and SOC3 from large to small.

[0063] SOC MAX : Power battery SOC safety upper limit, the value is greater than SOC H , less than 100%.

[0064] SOC MIN : Power battery SOC safety lower limit, the value is less than SOC L , greater than 0%.

[0065] Speed ​​threshold V S : The speed threshold of the vehicle moving forward.

[0066] P1: The average power of the vehicle during normal operation.

[0067] P2: The average power of the vehicle when running at high speed, uphill, or at full load.

[0068] When the vehicle is in EV mode, the fuel cell engine does not start. When the vehicle is in FC mode, the power distribution strategy is as follows:

[0069] (1) When the SOC of the power battery > SOC H , the fuel cell engine does not start;

[0070] (2) When the SOC of the power battery L < SOC < SOC H , when the vehicle speed is greater than or equal to V S , and the allowable charging power of the power battery > 20% DP_FC, the fuel cell engine starts;

[0071] (3) When the SOC of the power battery < SOC L , and the allowable charging power of the power battery > 10% DP_FC, the fuel cell engine starts when the vehicle starts in D gear;

[0072] (4) The output power range of the fuel cell engine is 20% DP_FC to 80% DP_FC;

[0073] (5) When the SOC of the power battery is between the SOC efficient regions, the SOC maintenance strategy is adopted. The real-time value of the output power of the fuel cell engine does not exceed the current allowable charging power of the power battery. When the power battery adopts the SOC maintenance strategy, the output power of the fuel cell engine linearly changes between 20% DP_FC and 70% DP_FC;

[0074] (6) When the power battery SOC1 ≤ SOC < SOC H , the output power of the fuel cell engine is P1;

[0075] (7) When the power battery SOC2 ≤ SOC < SOC1, the output power of the fuel cell engine is P_FC1;

[0076] (8) When the power battery SOC3 ≤ SOC < SOC2, the output power of the fuel cell engine is P2;

[0077] (9) When the power battery SOC MIN ≤ SOC < SOC3, the output power of the fuel cell engine is 90% DP_FC;

[0078] (10) When the power battery SOC < SOC MIN , the output power of the fuel cell engine is DP_FC;

[0079] (11) When any of the following conditions is met, the fuel cell engine shuts down:

[0080] (a) When the SOC of the power battery > SOC MAX ,

[0081] (b) The power battery allows charging power < 20% DP_FC,

[0082] (c) Use the key to switch to OFF position, EV mode, or the VCU requires shutdown.

[0083] Example 1

[0084] The relationship between power and efficiency of fuel-electric engines is determined.

[0085] Select 6 different types of vehicles in Table 1. All of these 6 vehicles are hydrogen fuel cell vehicles, using fuel-electric engines, and the power battery capacity is 100 kWh. The same model has different fuel-electric engines on the market. For example, for an 8-meter bus, some fuel-electric engines have good performance and can reach 51kw, while others only have 48kw, but this difference in power can meet actual use needs.

[0086] Table 1

[0087] Model\Power Fuel-electric engine power HWFET operating conditions NYCC Conditions 8m bus 48-51kW 42kW / 36kW 35kW / 30kW 10m bus 50-60kW 50kW / 42kW 40kW / 32kW 12m bus 62-70kW 60kW / 52kW 50kW / 42kW 7 tons logistics vehicle 37-46kW 35kW / 40kW 30kW / 26kW 13 tons logistics vehicle 62-70kW 60kW / 52kW 50kW / 42kW 18 tons logistics vehicle 72-80kW 70kW / 62kW 60kW / 52kW

[0088] The operating condition database used in the present study selected NYCC conditions, UDDS conditions and HWFET conditions, which represent urban conditions, suburban conditions and highway conditions respectively. The results of NYCC conditions and UDDS conditions are close, so only the data under NYCC conditions are given in Table 1.

[0089] The relevant parameters are defined as follows:

[0090] DP_FC: rated power of the fuel-electric engine.

[0091] P_FC1: The power at the high economic efficiency point of the fuel-electric engine.

[0092] P1: The average power of the vehicle in normal operation. The operating condition database used here selects the NYCC operating condition representing the urban operating condition, and is obtained based on the corresponding power integral of the vehicle.

[0093] P2: The average power of the vehicle when running at high speed, driving uphill, and running at full load. The operating condition database used to obtain the power is selected from the HWFET operating condition representing the highway operating condition, and the power is obtained based on the corresponding power integral of the vehicle.

[0094] Figure 1 Shown is the relationship between fuel-electric engine power and efficiency (%).

[0095] From the data in Table 1, it can be seen that under normal vehicle conditions, the power of the P1 fuel-electric engine is 50%-70% of the rated power, and under test conditions P2, it is 60%-80% of the rated power. In reality, the fuel-electric engine changes linearly between 20% DP_FC and 70% DP_FC, which can achieve the SOC maintenance strategy.

[0096] Example 2

[0097] The daily operation of the hydrogen fuel cell vehicle with a bus model of 8 meters in the above Example 1 was simulated and the actual operation was detected.

[0098] The operating parameters are shown in Table 2 below.

[0099] Table 2

[0100] Serial number project parameter 1 Lupu A city loop bus route 2 Mileage per lap (km) 21 3 Duration of each lap (s) 3900 4 Duration of each lap (s) 600 5 Average power per lap (kw) 20 6 Number of laps 7 7 Total mileage (km) 147 8 Accessory power (kw) 4.5 9 Initial SOC (%) 60

[0101] The values of each parameter are as follows:

[0102] The value of P_FC1 is taken as 70% of DP_FC;

[0103] SOC L is 40%, SOC H is 80%, SOC1 is taken as 70%, SOC2 is taken as 60%, and SOC3 is taken as 50%;

[0104] SOC MAX is taken as 90%, SOC MIN is taken as 25%;

[0105] P1 is 60% of DP_FC, and P2 is 80% of DP_FC.

[0106] The power distribution strategy in the typical FC mode is as follows:

[0107] (1) When SOC > 80% or in EV mode, the fuel cell engine does not start.

[0108] In FC mode:

[0109] (2) When 40% < SOC < 80%, the vehicle speed is greater than or equal to 15 km / h, and the allowable charging power of the power battery > 20 kW, the fuel cell system starts;

[0110] (3) When SOC < 40%, and the allowable charging power of the power battery > 20 kW, the fuel cell engine starts when the vehicle is in D gear and powered on.

[0111] (4) The output power range of the fuel cell engine is 20% of DP_FC to 80% of DP_FC;

[0112] (5) When SOC is between 40% - 80%, the SOC maintenance strategy is adopted, and the output power of the fuel cell engine varies linearly between 20% of DP_FC and 70% of DP_FC, and the real-time value does not exceed the current allowable charging power of the power battery;

[0113] (6) When 70% ≤ SOC < 80% of the power battery, the output power of the fuel cell engine is P1;

[0114] (7) Power battery 60%≤SOC<70%, fuel-electric engine output power 70%DP_FC;

[0115] (8) Power battery 50% ≤ SOC < 60%, fuel-electric engine output power P2;

[0116] (9) Power battery SOC MIN ≤SOC<50%, fuel-electric engine output power 90%DP_FC;

[0117] (10) Power battery SOC<SOC MIN , the fuel-electric engine output power DP_FC;

[0118] (11) The fuel-electric engine shuts down when any of the following conditions are met:

[0119] (a) SOC>SOC MAX , the fuel-electric engine is shut down,

[0120] (b) The power battery allows charging power < 20% DP_FC, the fuel-electric engine is shut down,

[0121] (c) Turn the key to the OFF position, EV mode or VCU requires shutdown, and the fuel-electric engine shuts down.

[0122] The overall power distribution method of hydrogen fuel cell buses simulates the power battery SOC and fuel-electric engine power changes as shown in the figure Figures 3 to 8 As shown, the horizontal axis is time, and the unit is 0.1S. A total of 3 sets of data were simulated, which are the cases where the initial SOC is 30%, 60% and 90%.

[0123] Among them, the initial SOC is 60%, and the SOC change curve of the power battery over time in the NYCC working condition simulation data is as follows: Figure 3 As shown in the figure, the power curve of the fuel-electric engine changes with time. Figure 4 The starting power of the fuel-electric engine is 15kw. According to the power distribution, the corresponding power of SOC 60% is 25kw. The power is slightly adjusted with the change of SOC. As can be seen from the figure, the SOC change is very small, and the power change range of the fuel-electric engine is relatively small. The longer the time, the more stable the power. There is no case that the power battery SOC exceeds SOC. MAX , and cause the fuel-electric engine to shut down. This not only extends the service life of the power battery, but also extends the service life of the fuel-electric engine.

[0124] The initial SOC is 30%, and the SOC variation curve of the power battery in the NYCC working condition simulation data is as follows: Figure 5 As shown in the figure, the power curve of the fuel-electric engine changes with time. Figure 6The starting power of the fuel-electric engine is 15kw. According to the power distribution, the power corresponds to SOC30%. Since the power of the power battery is limited to 35kw, the power tends to be stable as the SOC changes. As can be seen from the figure, SOC has an increasing trend in the early stage, and the change range is very small after SOC approaches 60%. In addition, the power change range of the fuel-electric engine is relatively small. The longer the time, the more stable the power. There is no case that the power battery SOC exceeds SOC. MAX The initial SOC is 90%, and the SOC variation curve of the power battery over time in the NYCC operating condition simulation data is as follows: Figure 7 As shown in the figure, the power curve of the fuel-electric engine changes with time. Figure 8 As shown in the figure, the fuel-electric engine does not start when SOC>80% in the early stage. When SOC<80%, the starting power of the fuel-electric engine is 15kw. According to the power distribution, SOC 80% corresponds to 15kw. SOC has a downward trend in the early stage. After SOC approaches 60%, the change range is very small, and the power change range of the fuel-electric engine is relatively small. The longer the time, the more stable the power. There is no SOC of the power battery exceeding SOC. MAX , and cause the fuel-electric engine to shut down.

[0125] Fig. 9 This is a graph of the actual power variation of the fuel-electric engine equipped with the overall power distribution method of the hydrogen fuel bus of this embodiment, with the horizontal axis being time, and the unit being 0.1S. It can be seen from the figure that due to the use of the onboard air conditioner, the power is about 2kw higher than the calculated value, but the overall effect is close to the simulation result.

[0126] Comparative Example 1

[0127] The daily operation of the hydrogen fuel cell vehicle of the 8-meter bus in the above-mentioned embodiment 1 is simulated, and the operating parameters are the same as those in Table 2 in embodiment 2.

[0128] Using the existing overall power distribution method for hydrogen fuel buses, the current control strategy allows the fuel-electric engine to change power with the power battery SOC at several specific power points ( Fig.10 ).

[0129] Fig.11 It is the curve of power battery SOC changing with time in simulation data. Fig.12This is a graph of the power of the fuel-electric engine changing with time in the simulation data. The horizontal axis is time, and the unit is 0.1S. The starting power of the fuel-electric engine is 12kw; when the SOC of the power battery is charged to 75%, the fuel-electric engine stops working, and then the SOC of the power battery must drop below 50% before the fuel-electric engine starts working. There is a hysteresis interval between the power change points of the fuel-electric engine, and the power change points include 30%, 60% and 90%. Taking the power change points of 30% and 60% as an example, when the SOC changes between 30% and 70%, the power hysteresis between the two points of 36kw and 12kw. It can be seen from the figure that the SOC changes greatly, and 5 of them exceed 80%, causing the fuel-electric engine to shut down until the SOC drops to 50%. The fuel-electric engine has a large power change range. The large change range of the power battery SOC leads to a rapid shortening of the power battery life; the fuel-electric engine starts and stops many times, which also accelerates the shortening of the fuel-electric engine life.

Claims

1. A method for distributing overall power of a hydrogen fuel cell vehicle, wherein the hydrogen fuel cell vehicle comprises a fuel-electric engine for generating electricity using hydrogen fuel, a power battery for power supply and energy storage, a main motor for driving the vehicle and energy recovery during braking, and other electrical components in the vehicle collectively referred to as vehicle accessories, characterized in that: Define the parameters as follows: DP_FC: rated power of the fuel-electric engine; P_FC1: power at the high economic efficiency point of the fuel-electric engine; Power battery SOC: power battery charge, the value is the ratio of remaining capacity to rated capacity; Power battery SOC high efficiency zone: indicates that the power battery power is within this range, and the power battery output efficiency is high. L Indicates the lower limit of the power battery SOC high efficiency zone, with SOC H Indicates the upper limit of the power battery SOC high efficiency zone. H and SOC L Three points are selected as auxiliary points for power calibration, and the values ​​of the three points are SOC1, SOC2, and SOC3 from large to small; SOC MAX : Power battery SOC safety upper limit, the value is greater than SOC H , less than 100%; SOC MIN : Power battery SOC safety lower limit, the value is less than SOC L , greater than 0%; Speed ​​threshold V S : The driving speed threshold of the vehicle; P1: average power of the vehicle in normal operation; P2: average power of the vehicle when running at high speed, uphill or at full load; When the vehicle is in EV mode, the fuel-electric engine is not started. When the vehicle is in FC mode, the power distribution strategy is as follows: (1) Power battery SOC>SOC H The fuel-electric engine does not start; (2) Power battery SOC L <SOC<SOC H When the vehicle speed is greater than or equal to V S , and the power battery allows charging power> 20% DP_FC, the fuel-electric engine starts; (3) Power battery SOC<SOC L When the power battery allows charging power> 10% DP_FC, the fuel-electric engine starts when the vehicle is in D gear; (4) The fuel-electric engine output power range is 20% DP_FC to 80% DP_FC; (5) When the power battery SOC is between the SOC high efficiency zones, the SOC maintenance strategy is adopted, and the real-time output power of the fuel-electric engine does not exceed the current allowable charging power of the power battery; (6) Power battery SOC1≤SOC<SOC H , the fuel-electric engine output power P1; (7) Power battery SOC2≤SOC<SOC1, fuel-electric engine output power P_FC1; (8) Power battery SOC3≤SOC<SOC2, fuel-electric engine output power P2; (9) Power battery SOC MIN When SOC3 ≤ SOC < SOC3, the output power of the fuel cell engine is 90% of DP_FC; (10) Power battery SOC<SOC MIN , the fuel-electric engine output power DP_FC; (11) The fuel-electric engine shuts down when any of the following conditions are met: (a) Power battery SOC>SOC MAX , (b) The power battery allows charging power < 20% DP_FC, (c) Use the key to switch to OFF position, EV mode, or the VCU requires shutdown.

2. The overall power distribution method for hydrogen fuel cell vehicles according to claim 1 is characterized in that: The value of P_FC1 is 70% DP_FC.

3. The overall power distribution method for hydrogen fuel cell vehicles according to claim 1 is characterized in that: The lower limit value SOC of the power battery high efficiency zone L The upper limit of the power battery SOC high efficiency zone is 40%. H is 80%.

4. The overall power distribution method for hydrogen fuel cell vehicles according to claim 3 is characterized in that: SOC1 is 70%, SOC2 is 60%, and SOC3 is 50%.

5. The overall power distribution method of a hydrogen fuel cell vehicle according to claim 1, characterized in that: SOC MAX Take 80%-90%.

6. The overall power distribution method for a hydrogen fuel cell vehicle according to claim 1, characterized in that: SOC MIN Take 20-30%.

7. The overall power distribution method for a hydrogen fuel cell vehicle according to claim 1, characterized in that: The operating condition database used when obtaining P1 selects the NYCC operating condition or the UDDS operating condition representing the urban operating condition or the suburban operating condition respectively; the operating condition database used when obtaining P2 selects the HWFET operating condition representing the highway operating condition.

8. The overall power distribution method for a hydrogen fuel cell vehicle according to claim 1, characterized in that: P1 is 50%DP_FC-70%DP_FC, and P2 is 60%DP_FC-80%DP_FC.

9. The overall power distribution method for a hydrogen fuel cell vehicle according to claim 1, characterized in that: In point (5), when the power battery adopts the SOC maintenance strategy, the fuel-electric engine changes linearly between 20% DP_FC and 70% DP_FC.

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