Power control method for fuel cell with high soc

Abstract

A power control method for a fuel cell with a high SOC, which method belongs to the technical field of power control of electric vehicles. The power control method comprises: on the basis of an operation of a driver and the current instantaneous state of a vehicle, obtaining a total required power, and acquiring an instantaneous maximum allowable discharge power of an auxiliary traction battery and an optimal output power of a fuel cell at an optimal operation efficiency point; and on the basis of the total required power, the instantaneous maximum allowable discharge power and the optimal output power, adjusting an output power of the fuel cell and a vehicle output power. By means of precisely calculating and limiting the total required power of the vehicle, a charge / discharge power of the auxiliary traction battery and the optimal output power of the fuel cell, a real-time output power of the fuel cell is precisely calculated, and the limit range of the vehicle output power is also provided, thereby effectively avoiding faults such as a fuel cell being blocked due to the fact that the output power of the fuel cell cannot be consumed.

Description

A power control method for fuel cell under high SOC TECHNICAL FIELD

[0001] The present application relates to the power control technology field of electric vehicles, in particular to a power control method for fuel cell under high SOC. BACKGROUND

[0002] At present, the main power source of fuel cell vehicles is fuel cell, and the output power of fuel cell changes relatively gently. If the demand of the whole vehicle changes rapidly, an auxiliary power battery needs to be used as power compensation or consumption. However, in a full-power fuel cell vehicle, in order to reduce the cost and difficulty of the whole vehicle design, only a small auxiliary power battery is often selected, that is, the maximum chargeable and dischargeable power of the auxiliary power battery is very limited. Under the condition that the SOC of the auxiliary power battery is high, the chargeable power is very small. If the driver needs to perform emergency deceleration operation at this time, and the output power of the fuel cell is at a high level, the accurate calculation and limitation of the output power of the fuel cell and the output power of the whole vehicle are lacking, and the output power of the fuel cell cannot be consumed, which may cause the fuel cell to be blocked and other faults.

[0003] Among them, SOC, full name is State of Charge, is the battery state of charge, also called the remaining power. SUMMARY

[0004] Therefore, the present application provides a power control method for fuel cell under high SOC, so as to solve the problem that the accurate calculation and limitation of the output power of the fuel cell and the output power of the whole vehicle are lacking in the prior art, so that the output power of the fuel cell cannot be consumed, which may cause the fuel cell to be blocked and other faults.

[0005] In a first aspect, a power control method for fuel cell under high SOC is provided, and the method comprises:

[0006] Obtaining the total demand power of the electric vehicle, the instantaneous maximum allowable discharge power of the auxiliary power battery, and the optimal output power of the fuel cell optimal working efficiency point;

[0007] Adjusting the output power of the fuel cell and the output power of the whole vehicle according to the total demand power, the instantaneous maximum allowable discharge power and the optimal output power.

[0008] Further, the adjusting the output power of the fuel cell and the output power of the whole vehicle according to the total demand power, the instantaneous maximum allowable discharge power and the optimal output power comprises:

[0009] Taking the smaller power between the instantaneous maximum allowable discharge power and the optimal output power as a first intermediate power;

[0010] if the total demand power is less than or equal to the first intermediate power;

[0011] obtaining a fuel cell instantaneous output power, a maximum change output power and an instantaneous maximum allowable charging power of an auxiliary power battery; the maximum change output power is a maximum output power change value of the fuel cell within a single sampling interval;

[0012] obtaining a first power range according to the fuel cell instantaneous output power, the maximum change output power, the instantaneous maximum allowable charging power and an instantaneous maximum allowable discharging power;

[0013] setting the fuel cell output power to 0 and controlling the vehicle output power to fall within the first power range.

[0014] Further, the obtaining of the first power range according to the fuel cell instantaneous output power, the maximum change output power, the instantaneous maximum allowable charging power and the instantaneous maximum allowable discharging power comprises:

[0015] obtaining the first power range through a first formula, the first formula being:

[0016] Max{ 0 ,P fc -△P fc} - P char_pek ≤ P _VCUReqVeh ≤ Max{ 0 ,P fc -△P fc}+ P dis_pek ;

[0017] wherein P fc is the fuel cell instantaneous output power, △P fc is the maximum change output power, P char_pek is the instantaneous maximum allowable charging power of the current auxiliary power battery, P dis_pek is the instantaneous maximum allowable discharging power of the current auxiliary power battery; and P _VCUReqVeh is the vehicle output power.

[0018] Further, the method further comprises:

[0019] if the total demand power is greater than the first intermediate power;

[0020] taking the greater one of the instantaneous maximum allowable discharging power and the optimal output power as a second intermediate power;

[0021] if the total demand power is less than or equal to the second intermediate power and the optimal output power is less than or equal to the instantaneous maximum allowed discharging power, obtaining a second power range according to the optimal output power and the instantaneous output power of the fuel cell;

[0022] setting the fuel cell output power as the optimal output power, and controlling the vehicle output power to fall within the second power range.

[0023] Further, the obtaining of the second power range according to the optimal output power and the instantaneous output power of the fuel cell comprises:

[0024] if the optimal output power is less than or equal to the instantaneous output power of the fuel cell, obtaining the second power range by a second formula, the second formula being:

[0025] Max { P fc_max ,P fc -△P fc}-P char_pek ≤P _VCUReqVeh ≤Max { P fc_max ,P fc -△P fc} + P dis_pek ;

[0026] if the optimal output power is greater than the instantaneous output power of the fuel cell, obtaining the second power range by a third formula, the third formula being:

[0027] Min { P fc_max ,P fc +△P fc}-P char_pek ≤ P _VCUReqVeh ≤Min { P fc_max ,P fc +△P fc}+ P dis_pek ;

[0028] wherein P fc_max is the optimal output power, P fc is the instantaneous output power of the fuel cell,△P fc is the maximum change output power, P char_pek is the instantaneous maximum allowed charging power of the current auxiliary power battery, P dis_pek is the instantaneous maximum allowed discharging power of the current auxiliary power battery; and P _VCUReqVeh is the vehicle output power.

[0029] Further, the method further comprises:

[0030] If the total demand power is less than or equal to the second intermediate power, and the optimal output power is greater than the instantaneous maximum allowed discharging power, a target output power is obtained according to the total demand power, the instantaneous maximum allowed discharging power, a first SOC difference value and a second SOC difference value; the first SOC difference value is a difference value between a current instantaneous SOC of the auxiliary power battery and an SOC expected value; the second SOC difference value is a difference value between a highest SOC value allowed to be charged and a lowest SOC value allowed to be discharged of the auxiliary power battery;

[0031] A third power range is obtained according to the target output power and the instantaneous output power of the fuel cell;

[0032] The fuel cell output power is set as the target output power, and the whole vehicle output power is controlled to fall within the third power range.

[0033] Further, the target output power is obtained according to the total demand power, the instantaneous maximum allowed discharging power, the first SOC difference value and the second SOC difference value, including:

[0034] The target output power is obtained by a fourth formula, the fourth formula being:

[0035] P _VCUReqFCU = P-P dis_pek ×△SOC exp / △SOC rang ;

[0036] Wherein, P _VCUReqFCU is the target output power, P is the total demand power, P dis_pek is the current instantaneous maximum allowed discharging power of the auxiliary power battery, △SOC exp is the first SOC difference value, i.e. a difference value between the current instantaneous SOC of the auxiliary power battery and the SOC expected value, and △SOC rang is the second SOC difference value, i.e. a difference value between the highest SOC value allowed to be charged and the lowest SOC value allowed to be discharged of the auxiliary power battery.

[0037] Further, the third power range is obtained according to the target output power and the instantaneous output power of the fuel cell, including:

[0038] If the target output power is less than or equal to the instantaneous output power of the fuel cell, the third power range is obtained by a fifth formula, the fifth formula being:

[0039] Max{P-P dis_pek ×△SOC exp / △SOC rang ,P fc -△P fc} - P char_pek ≤ P _VCUReqVeh ≤ Max{P - P dis_pek ×△SOC exp / △SOC rang , P fc +△P fc} + P dis_pek ;

[0040] If the target output power is greater than the instantaneous output power of the fuel cell, the third power range is obtained by a sixth formula, which is:

[0041] Min{P - P dis_pek ×△SOC exp / △SOC rang , P fc +△P fc} - P char_pek ≤ P _VCUReqVeh ≤ Max{P - P dis_pek ×△SOC exp / △SOC rang , P fc +△P fc} + P dis_pek ;

[0042] Wherein, P is the total demand power, P dis_pek is the instantaneous maximum allowable discharge power of the current auxiliary power battery,△SOC exp is the first SOC difference,△SOC rang is the second SOC difference, P fc is the instantaneous output power of the fuel cell,△P fc is the maximum change output power, P char_pek is the instantaneous maximum allowable charging power of the current auxiliary power battery, P _VCUReqVeh is the total vehicle output power.

[0043] Further, the method further comprises:

[0044] If the total demand power is greater than the second intermediate power;

[0045] Adding the instantaneous maximum allowable discharge power and the optimal output power to obtain a third intermediate power;

[0046] If the total demand power is less than or equal to the third intermediate power, the fuel cell output power is set as the optimal output power; if the optimal output power is less than or equal to the fuel cell instantaneous output power, the vehicle output power is controlled to fall within the second power range obtained by a second formula; if the optimal output power is greater than the fuel cell instantaneous output power, the vehicle output power is controlled to fall within the second power range obtained by a third formula.

[0047] Further, the method further comprises:

[0048] If the total demand power is greater than the third intermediate power, the fuel cell output power is set as the target output power; if the target output power is less than or equal to the fuel cell instantaneous output power, the vehicle output power is controlled to fall within the third power range obtained by a fifth formula; if the target output power is greater than the fuel cell instantaneous output power, the vehicle output power is controlled to fall within the third power range obtained by a sixth formula.

[0049] The present application adopts the above technical solution and has at least the following beneficial effects:

[0050] A power control method for fuel cell under high SOC is provided, the total demand power is obtained according to the operation of the driver and the current state of the vehicle, the instantaneous maximum allowable discharge power of the auxiliary power battery and the optimal output power of the fuel cell optimal working efficiency point are obtained, the fuel cell output power and the vehicle output power are adjusted according to the total demand power, the instantaneous maximum allowable discharge power and the optimal output power; the total demand power of the vehicle, the charge and discharge power of the auxiliary power battery and the optimal output power of the fuel cell are accurately calculated and limited, the accurate calculation of the real-time output power of the fuel cell is realized, and the limitation range of the vehicle output power is given, so that the fuel cell blockage and other failures caused by the failure of the fuel cell output power to be consumed are effectively avoided.

[0051] It should be understood that the foregoing general description and the following detailed description are only exemplary and explanatory, and cannot limit the present application. BRIEF DESCRIPTION OF DRAWINGS

[0052] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed in the embodiment or prior art description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, and those skilled in the art can also obtain other drawings according to these drawings without creative labor.

[0053] FIG. 1 is a flowchart of a power control method for fuel cell under high SOC according to an exemplary embodiment of the present application.

[0054] Figure 2 is a flow chart illustrating a method for power control of a fuel cell at a high SOC according to another exemplary embodiment of the present application. DETAILED DESCRIPTION

[0055] For the purpose of making the present application, technical solutions and advantages more clear, the present application is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and not intended to limit the present application.

[0056] Currently, the output power of the fuel cell, which is the main power source of the fuel cell vehicle, changes relatively slowly and cannot be abruptly changed. If the demand of the vehicle changes rapidly, an auxiliary power battery needs to be used as a power compensation or consumption. However, in a full-power fuel cell vehicle, in order to reduce the cost and the difficulty of the vehicle design, only a small power battery is often selected, i.e., the maximum chargeable and dischargeable power of the small power battery is very limited. Under the condition that the remaining power of the auxiliary power battery is high, the chargeable power of the small power battery is very small. If the driver needs to perform an emergency deceleration operation at this time, and the output power of the fuel cell is at a high level, the output power of the fuel cell cannot be consumed, which may cause the fuel cell to be blocked and other faults.

[0057] The embodiment of the application provides a fuel cell high-SOC power control method, aiming at the problems of low fuel cell output power change rate of a full-power fuel cell vehicle, small auxiliary power battery electric quantity, and difficult driving control under the condition of high battery SOC, a fuel cell vehicle power calculation and driving control method under high SOC is designed, the total power demand of the vehicle, the auxiliary power battery charging and discharging power and the optimal output power of the fuel cell are accurately calculated and limited, and the purpose of vehicle output power matching and smooth control is achieved. The method is based on the highest working efficiency point of the fuel cell, so that the fuel cell vehicle can work around the highest working efficiency point as much as possible, thereby improving the working efficiency of the vehicle and reducing the energy consumption of the vehicle. Based on the defect that the fuel cell power cannot be suddenly increased or decreased, various operating conditions of the vehicle are classified, and the maximum boundary of the fuel cell power change is included in the VCU request vehicle output power calculation model, so that the VCU request vehicle output power is accurately calculated and limited, and potential fault hidden dangers caused by the sudden increase or decrease of the fuel cell power are eliminated. The application can not only make the fuel cell work around the highest working efficiency point under high SOC of the power battery, but also make the power battery discharge continuously at a fast, intelligent and dynamic discharge rate, so that the power battery gradually approaches the SOC expectation value, and the performance and cycle life of the power battery are improved. The VCU request fuel cell output power, the VCU request vehicle output power and the power battery discharging power are predicted, calculated and limited under different conditions, so that the vehicle output power is matched, and the vehicle can be efficiently, effectively and stably operated. The VCU is a vehicle controller.

[0058] The method in the application will be described below through specific embodiments.

[0059] Please refer to Fig. 1, which is a flow chart of a fuel cell high-SOC power control method according to an exemplary embodiment of the application. As shown in Fig. 1, the method comprises the following steps:

[0060] In step S11, the total power demand of the electric vehicle, the instantaneous maximum allowable discharging power of the auxiliary power battery and the optimal output power of the fuel cell optimal working efficiency point are obtained.

[0061] In step S12, the fuel cell output power and the vehicle output power are adjusted according to the total power demand, the instantaneous maximum allowable discharging power and the optimal output power.

[0062] It should be noted that the technical scheme provided in the embodiment can be applied to the following scenarios, but is not limited to the following scenarios: an electric vehicle with a fuel cell as the main power source and other devices with a fuel cell as the main power source.

[0063] It can be understood that the power control method provided by the embodiment realizes accurate calculation of the real-time output power of the fuel cell, while giving the limiting range of the output power of the whole vehicle, and effectively avoids the fuel cell blockage caused by the fact that the output power of the fuel cell cannot be consumed.

[0064] In specific practice, the step S11 of "obtaining the total demand power of the electric vehicle, the instantaneous maximum allowable discharge power of the auxiliary power battery and the optimal output power of the fuel cell optimal working efficiency point" includes: when the fuel cell SOC is higher than the expected value and in the driving working condition of the whole vehicle, the whole vehicle controller calculates the total demand power according to the operation of the driver and the current instantaneous state of the whole vehicle.

[0065] It should be noted that the instantaneous maximum allowable discharge power of the auxiliary power battery is obtained from the battery parameter database according to the temperature, the battery type and the instantaneous SOC state; the data in the battery parameter database is obtained according to multiple specific experiments; and the optimal output power of the fuel cell optimal working efficiency point is provided by the fuel cell manufacturer.

[0066] In specific practice, the step S12 of "adjusting the fuel cell output power and the whole vehicle output power according to the total demand power, the instantaneous maximum allowable discharge power and the optimal output power" includes: taking the smaller power between the instantaneous maximum allowable discharge power and the optimal output power as a first intermediate power; if the total demand power is less than or equal to the first intermediate power, obtaining the instantaneous output power of the fuel cell, the maximum change output power and the instantaneous maximum allowable charging power of the auxiliary power battery; the maximum change output power is the maximum output power change value of the fuel cell within a single sampling interval; obtaining a first power range according to the instantaneous output power of the fuel cell, the maximum change output power, the instantaneous maximum allowable charging power and the instantaneous maximum allowable discharge power; setting the fuel cell output power to 0, and controlling the whole vehicle output power to fall within the first power range.

[0067] It should be noted that the instantaneous output power of the fuel cell and the maximum change output power are real-time collected data, and the maximum change output power is the maximum output power change value of the fuel cell within a single sampling interval; and the instantaneous maximum allowable charging power of the auxiliary power battery is obtained from the battery parameter database according to the temperature, the battery type and the instantaneous SOC state.

[0068] Specifically, the first power range is obtained by a first formula, and the first formula is:

[0069] Max{ 0 ,P fc -△P fc} - Pchar_pek ≤ P _VCUReqVeh ≤ Max{ 0 ,P fc -△P fc}+ P dis_pek Among them, P fc For the instantaneous output power of the fuel cell, ΔP fc For maximum variable output power, P char_pek P represents the maximum permissible instantaneous charging power of the current auxiliary power battery. dis_pek P represents the maximum permissible instantaneous discharge power of the current auxiliary power battery. _VCUReqVeh This refers to the total output power of the vehicle.

[0070] In practice, this also includes: if the total power demand is greater than the first intermediate power; take the larger of the instantaneous maximum allowable discharge power and the optimal output power as the second intermediate power; if the total power demand is less than or equal to the second intermediate power, and the optimal output power is less than or equal to the instantaneous maximum allowable discharge power, then obtain the second power range based on the optimal output power and the instantaneous output power of the fuel cell; set the fuel cell output power to the optimal output power, while controlling the overall vehicle output power to fall within the second power range.

[0071] Specifically, if the optimal output power is less than or equal to the instantaneous output power of the fuel cell, the second power range is obtained through the second formula, which is:

[0072] Max { P fc_max ,P fc -△P fc}-P char_pek ≤P _VCUReqVeh ≤Max { P fc_max ,P fc -△P fc} + P dis_pek ;

[0073] If the optimal output power is greater than the instantaneous output power of the fuel cell, then the second power range can be obtained through the third formula, which is:

[0074] Min { P fc_max ,P fc +△P fc}-P char_pek ≤ P _VCUReqVeh ≤Min { P fc_max ,P fc +△P fc}+ P dis_pek ;

[0075] Among them, P fc_maxP fc is the instantaneous output power of the fuel cell fc is the maximum change output power, P char_pek is the instantaneous maximum allowed discharge power allowed by the current auxiliary power battery; P dis_pek is the instantaneous maximum allowed discharge power allowed by the current auxiliary power battery; P _VCUReqVeh is the total power demand.

[0076] In specific practice, it also includes: if the total power demand is less than or equal to the second intermediate power, and the optimal output power is greater than the instantaneous maximum allowed discharge power, then obtaining a target output power according to the total power demand, the instantaneous maximum allowed discharge power, a first SOC difference and a second SOC difference; obtaining a third power range according to the target output power and the instantaneous output power of the fuel cell; and setting the output power of the fuel cell as the target output power, while controlling the total power output to fall within the third power range.

[0077] It should be noted that the first SOC difference is the difference between the current instantaneous SOC of the auxiliary power battery and the SOC expectation value; the second SOC difference is the difference between the highest SOC value allowed to be charged and the lowest SOC value allowed to be discharged by the auxiliary power battery; the current instantaneous SOC of the auxiliary power battery is collected in real time, the SOC expectation value of the auxiliary power battery is obtained according to multiple experiments, and the highest SOC value allowed to be charged and the lowest SOC value allowed to be discharged by the auxiliary power battery are provided by the manufacturer; and they are obtained from the corresponding database of the manufacturer.

[0078] Specifically, the target output power is obtained by a fourth formula, which is:

[0079] P _VCUReqFCU = P-P dis_pek ×△SOC exp / △SOC rang ;

[0080] wherein, P _VCUReqFCU is the target output power, P is the total power demand, P dis_pek is the instantaneous maximum allowed discharge power allowed by the current auxiliary power battery,△SOC exp is the first SOC difference, i.e., the difference between the current instantaneous SOC of the auxiliary power battery and the SOC expectation value,△SOC rang is the second SOC difference, i.e., the difference between the highest SOC value allowed to be charged and the lowest SOC value allowed to be discharged by the auxiliary power battery.

[0081] Specifically, if the target output power is less than or equal to the instantaneous output power of the fuel cell, a third power range is obtained by a fifth formula, which is:

[0082] Max{P-Pdis_pek x ASOC exp / ASOC rang , P fc - AP fc} + P char_pek ≤ P _VCUReqVeh ≤ Max{P - P dis_pek x ASOC exp / ASOC rang , P fc + AP fc} + P dis_pek ;

[0083] If the target output power is greater than the instantaneous output power of the fuel cell, a third power range is obtained by a sixth formula, and the sixth formula is:

[0084] Min{P - P dis_pek x ASOC exp / ASOC rang , P fc + AP fc} - P char_pek ≤ P _VCUReqVeh ≤ Max{P - P dis_pek x ASOC exp / ASOC rang , P fc + AP fc} + P dis_pek ;

[0085] Wherein, P is the total demand power, P dis_pek is the instantaneous maximum allowable discharge power allowed by the current auxiliary power battery, ASOC exp is the first SOC difference, ASOC rang is the second SOC difference, P fc is the instantaneous output power of the fuel cell, AP fc is the maximum change output power, P char_pek is the instantaneous maximum allowable charge power allowed by the current auxiliary power battery, P _VCUReqVeh is the vehicle output power.

[0086] In specific practice, it also includes: if the total demand power is greater than the second intermediate power; the instantaneous maximum allowable discharge power and the optimal output power are added to obtain a third intermediate power; if the total demand power is less than or equal to the third intermediate power, the fuel cell output power is set to the optimal output power; if the optimal output power is less than or equal to the instantaneous output power of the fuel cell, the vehicle output power is controlled to fall within the second power range obtained by the second formula; if the optimal output power is greater than the instantaneous output power of the fuel cell, the vehicle output power is controlled to fall within the second power range obtained by the third formula.

[0087] In the specific practice, it also includes: if the total demand power is greater than the third intermediate power, setting the fuel cell output power as the target output power; if the target output power is less than or equal to the fuel cell instantaneous output power, controlling the vehicle output power to fall into the third power range obtained by the fifth formula; if the target output power is greater than the fuel cell instantaneous output power, controlling the vehicle output power to fall into the third power range obtained by the sixth formula.

[0088] In one specific embodiment, please refer to Fig. 2, which is a flow chart of a fuel cell high SOC power control method according to another exemplary embodiment of the present application. As shown in Fig. 2, the fuel cell high SOC power control method includes:

[0089] When the fuel cell SOC is higher than the expected value and in the vehicle driving working condition, the vehicle controller (VCU) calculates the total demand power P according to the driver's operation and the current instantaneous state of the vehicle.

[0090] The VCU collects the current instantaneous maximum allowable discharge power value P dis_pek of the auxiliary power battery and the optimal output power value P fc_max corresponding to the optimal working efficiency point of the fuel cell, compares the two and takes the minimum value Min{P fc_max ,P dis_pek};

[0091] Step S21: comparing the total demand power P of the driver and Min{P fc_max ,P dis_pek};

[0092] If P≤ Min{P fc_max ,P dis_pek}, the VCU requests the output power P _VCUReqFCU of the fuel cell to be 0, and limits the vehicle output power P _VCUReqVeh requested by the VCU, i.e.:

[0093] Max { 0 ,P fc -△P fc} - P char_pek ≤ P _VCUReqVeh ≤Max { 0 ,P fc -△P fc}+ P dis_pek ;

[0094] If P> Min{P fc_max ,P dis_pek}, directly enter step S22.

[0095] Step S22: Compare the total power P and P fc_max , P dis_pek , and if P ≤ Max{P fc_max , P dis_pek}, go to step S23, otherwise go to step S26. fc_max dis_pek

[0096] Step S23: Compare P fc_max and P dis_pek :

[0097] If P fc_max ≤ P dis_pek , the VCU requests the output power of the fuel cell as: P _VCUReqFCU = P fc_max , and go to step S24;

[0098] If P fc_max > P dis_pek , the VCU requests the output power of the fuel cell as: P _VCUReqFCU = P-P dis_pek ×△SOC exp / △SOC rang , and go to step S25;

[0099] Step S24: Compare P fc_max and the instantaneous output power value P fc of the fuel cell:

[0100] If P fc_max ≤ P fc , limit the VCU requested vehicle output power P _VCUReqVeh , i.e.:

[0101] Max { P fc_max ,P fc -△P fc}-P char_pek ≤P _VCUReqVeh ≤Max { P fc_max ,P fc -△P fc} + P dis_pek

[0102] Otherwise if P fc_max > P fc , limit the VCU requested vehicle output power P _VCUReqVeh , i.e.:

[0103] Min { P​​fc_max P fc +△P fc}-P char_pek ≤ P _VCUReqVeh ≤Min { P fc_max ,P fc +△P fc}+ P dis_pek

[0104] Step S25: comparing P-P dis_pek ×△SOC exp / △SOC rang and the current fuel cell output power value P fc

[0105] If P-P dis_pek ×△SOC exp / △SOC rang ≤ P fc , the vehicle output power P _VCUReqVeh requested by the VCU is limited, i.e.:

[0106] Max{P-P dis_pek ×△SOC exp / △SOC rang ,P fc -△P fc}-P char_pek ≤P _VCUReqVeh ≤Max{P-P dis_pek ×△SOC exp / △SOC rang , P fc -△P fc}+ P dis_pek ;

[0107] If P-P dis_pek ×△SOC exp / △SOC rang > P fc , the vehicle output power P _VCUReqVeh requested by the VCU is limited, i.e.:

[0108] Min {P-P dis_pek ×△SOC exp / △SOC rang , P fc +△P fc}-P char_pek ≤P _VCUReqVeh ≤Max {P-P dis_pek ×△SOC exp / △SOC rang ,P fc +△P​fc}+P dis_pek

[0109] Step S26: add P dis_pek and P fc_max and compare with P

[0110] If P≤P fc_max +P dis_pek , the VCU requests the output power of the fuel cell to be P _VCUReqFCU = P fc_max , and proceeds to step S27;

[0111] If P>P fc_max +P dis_pek , the VCU requests the output power of the fuel cell to be P _VCUReqFCU = P-P dis_pek ×△SOC exp / △SOC rang , and proceeds to step S28;

[0112] Step S27: compare P fc_max and the current instantaneous fuel cell output power value P fc

[0113] If P fc_max ≤ P fc , limit the VCU requested vehicle output power P _VCUReqVeh , i.e.:

[0114] Max { P fc_max ,P fc -△P fc}-P char_pek ≤P _VCUReqVeh ≤Max { P fc_max ,P fc -△P fc} + P dis_pek

[0115] If P fc_max >P fc , limit the VCU requested vehicle output power P _VCUReqVeh , i.e.:

[0116] Min { P fc_max ,P fc +△P fc}-P char_pek ≤ P _VCUReqVeh ≤Min { P fc_max ,P fc +△P fc}+ P​dis_pek

[0117] Step S28: comparing P-P dis_pek x△SOC exp / △SOC rang and the current instantaneous fuel cell output power value P fc

[0118] If P-P dis_pek x△SOC exp / △SOC rang ≤ P fc , the vehicle output power P _VCUReqVeh requested by the VCU is limited, i.e.:

[0119] Max {P-P dis_pek x△SOC exp / △SOC rang , P fc -△P fc}-P char_pek ≤ P _VCUReqVeh ≤ Max {P-P dis_pek x△SOC exp / △SOC rang , P fc -△P fc}+ P dis_pek

[0120] If P-P dis_pek x△SOC exp / △SOC rang > P fc , the vehicle output power P _VCUReqVeh requested by the VCU is limited, i.e.:

[0121] Min {P-P dis_pek x△SOC exp / △SOC rang , P fc +△P fc}-P char_pek ≤ P _VCUReqVeh ≤ Max {P-P dis_pek x△SOC exp / △SOC rang , P fc +△P fc}+ P dis_pek .

[0122] ​The above-described embodiments are merely illustrative for the several embodiments of the present application, and the description is relatively specific and detailed, but should not be understood as limiting the scope of the patent. It should be noted that, for those of ordinary skill in the art, several modifications and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims.

[0123] Those of ordinary skill in the art can understand that all or part of the processes in the above-mentioned embodiments can be completed by a computer program instructing relevant hardware, and the computer program can be stored in a non-volatile computer readable storage medium. When the computer program is executed, it can include the processes of the above-mentioned embodiments. In the embodiments provided by the present application, any reference to memory, storage, database or other medium can include non-volatile and / or volatile memory. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM) or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. As an illustration but not limitation, RAM is available in various forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM), etc.

[0124] The technical features of the above embodiments can be combined in any way. To make the description concise, not all possible combinations of the technical features in the above embodiments are described, but as long as the combinations of the technical features do not exist contradictions, they should be considered as the scope of the present application.

[0125] The above-described embodiments are merely illustrative for the several embodiments of the present application, and the description is relatively specific and detailed, but should not be understood as limiting the scope of the patent. It should be noted that, for those of ordinary skill in the art, several modifications and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims.

Claims

1. A method of power control for a fuel cell at high SOC, characterized by, The method comprises: acquiring total demand power of the electric vehicle, instantaneous maximum allowable discharge power of the auxiliary power battery, and optimal output power of the fuel cell optimal working efficiency point; adjusting the fuel cell output power and the vehicle output power according to the total demand power, the instantaneous maximum allowable discharge power, and the optimal output power.

2. The method of claim 1, wherein, The adjusting the fuel cell output power and the vehicle output power according to the total demand power, the instantaneous maximum allowable discharge power, and the optimal output power comprises: taking the smaller power between the instantaneous maximum allowable discharge power and the optimal output power as a first intermediate power; if the total demand power is less than or equal to the first intermediate power; acquiring instantaneous fuel cell output power, maximum change output power, and instantaneous maximum allowable charge power of the auxiliary power battery; the maximum change output power is a maximum output power change value of the fuel cell within a single sampling interval; obtaining a first power range according to the instantaneous fuel cell output power, the maximum change output power, the instantaneous maximum allowable charge power, and the instantaneous maximum allowable discharge power; setting the fuel cell output power to 0 and controlling the vehicle output power to fall within the first power range.

3. The method of claim 2, wherein, The obtaining the first power range according to the instantaneous fuel cell output power, the maximum change output power, the instantaneous maximum allowable charge power, and the instantaneous maximum allowable discharge power comprises: obtaining the first power range through a first formula; the first formula is: Max{ 0 ,P fc -△P fc} - P char_pek ≤ P _VCUReqVeh ≤ Max{ 0 ,P fc -△P fc}+ P dis_pek ; wherein P fc is the fuel cell instantaneous output power, ΔP fc is the maximum change output power, P char_pek is the instantaneous maximum allowed charging power allowed by the current auxiliary power battery; P dis_pek is the instantaneous maximum allowed discharging power allowed by the current auxiliary power battery; P _VCUReqVeh is the vehicle output power.

4. The method of claim 2, wherein, The method further comprises: if the total demand power is greater than the first intermediate power; taking the larger power between the instantaneous maximum allowable discharge power and the optimal output power as a second intermediate power; if the total demand power is less than or equal to the second intermediate power and the optimal output power is less than or equal to the instantaneous maximum allowable discharge power, obtaining a second power range according to the optimal output power and the instantaneous fuel cell output power; setting the fuel cell output power to the optimal output power and controlling the vehicle output power to fall within the second power range.

5. The method of claim 4, wherein, The obtaining the second power range according to the optimal output power and the instantaneous fuel cell output power comprises: if the optimal output power is less than or equal to the instantaneous fuel cell output power, obtaining the second power range through a second formula; the second formula is: Max { P fc_max ,P fc -△P fc}-P char_pek ≤P _VCUReqVeh ≤Max { P fc_max ,P fc -△P fc} + P dis_pek ; if the optimal output power is greater than the instantaneous fuel cell output power, obtaining the second power range through a third formula; the third formula is: Min { P fc_max ,P fc +△P fc}-P char_pek ≤ P _VCUReqVeh ≤Min { P fc_max ,P fc +△P fc}+ P dis_pek ; where P fc_max is the optimal output power, P fc is the fuel cell instantaneous output power, ΔP fc is the maximum change output power, P char_pek is the current auxiliary power battery allowed instantaneous maximum allowed charging power, P dis_pek is the current auxiliary power battery allowed instantaneous maximum allowed discharging power; P _VCUReqVeh is the vehicle output power.

6. The method of claim 5, wherein, The method further comprises: if the total demand power is less than or equal to the second intermediate power and the optimal output power is greater than the instantaneous maximum allowable discharge power, obtaining a target output power according to the total demand power, the instantaneous maximum allowable discharge power, a first SOC difference value, and a second SOC difference value; the first SOC difference value is a difference value between a current instantaneous SOC of the auxiliary power battery and an SOC expectation value; the second SOC difference value is a difference value between a maximum SOC value allowed to be charged and a minimum SOC value allowed to be discharged of the auxiliary power battery; obtaining a third power range according to the target output power and the instantaneous fuel cell output power; The fuel cell output power is set to the target output power while controlling the vehicle output power to fall within the third power range.

7. The method of claim 6, wherein, The target output power is obtained according to the total demand power, the instantaneous maximum allowed discharge power, a first SOC difference and a second SOC difference. The target output power is obtained by a fourth formula, which is: P _VCUReqFCU = P-P dis_pek ×△SOC exp / △SOC rang ; wherein P _VCUReqFCU is the target output power, P is the total demand power, P dis_pek is the instantaneous maximum allowed discharge power allowed by the current auxiliary power battery, ΔSOC exp is the first SOC difference, i.e. the difference between the current instantaneous SOC of the auxiliary power battery and the SOC desired value, ΔSOC rang is the second SOC difference, i.e. the difference between the maximum SOC value allowed to be charged and the minimum SOC value allowed to be discharged by the auxiliary power battery.

8. The method of claim 7, wherein, The third power range is obtained according to the target output power and the fuel cell instantaneous output power, and includes: If the target output power is less than or equal to the fuel cell instantaneous output power, the third power range is obtained by a fifth formula, which is: Max{P-P dis_pek ×△SOC exp / △SOC rang ,P fc -△P fc}-P char_pek ≤P _VCUReqVeh ≤Max{P-P dis_pek ×△SOC exp / △SOC rang , P fc -△P fc}+ P dis_pek ; If the target output power is greater than the fuel cell instantaneous output power, the third power range is obtained by a sixth formula, which is: Min{P-P dis_pek ×△SOC exp / △SOC rang ,P fc +△P fc}-P char_pek ≤P _VCUReqVeh ≤Max{P-P dis_pek ×△SOC exp / △SOC rang ,P fc +△P fc}+P dis_pek ; P = P + P dis_pek P = P + P exp P = P + P rang P = P + P fc P = P + P fc P = P + P char_pek P = P + P _VCUReqVeh P = P + P 9. The method of claim 8, wherein, The method further includes: If the total demand power is greater than the second intermediate power; The instantaneous maximum allowed discharge power is added to the optimal output power to obtain a third intermediate power. If the total demand power is less than or equal to the third intermediate power, the fuel cell output power is set to the optimal output power; if the optimal output power is less than or equal to the fuel cell instantaneous output power, the vehicle output power is controlled to fall within the second power range obtained by the second formula; and if the optimal output power is greater than the fuel cell instantaneous output power, the vehicle output power is controlled to fall within the second power range obtained by the third formula.

10. The method of claim 9, wherein, The method further includes: If the total demand power is greater than the third intermediate power, the fuel cell output power is set to the target output power; if the target output power is less than or equal to the fuel cell instantaneous output power, the vehicle output power is controlled to fall within the third power range obtained by the fifth formula; and if the target output power is greater than the fuel cell instantaneous output power, the vehicle output power is controlled to fall within the third power range obtained by the sixth formula.

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