阅读说明：本技术 一种燃料电池整车能量分配方法 (Fuel cell whole vehicle energy distribution method ) 是由 刘江 于 2021-10-31 设计创作，主要内容包括：本发明提供一种燃料电池整车能量分配方法,该能量分配方法以动力电池、电堆和整车功率需求为输入量,主要参数为SOC、电堆变载能力p、电机或整车功率需求P1及当前电堆输出功率P2,设定电堆输出功率P为满足电堆条件的随动功率,将电堆输出功率P作为闭环系统的输入进行随动控制,从而使得荷电状态变化更为平缓,有效的提高动力电池和燃料电池寿命,提高了综合续航能力。(The invention provides a fuel cell vehicle energy distribution method, which takes power requirements of a power cell, a galvanic pile and a vehicle as input quantities, main parameters are SOC, the variable load capacity P of the galvanic pile, the power requirement P1 of a motor or the vehicle and the current output power P2 of the galvanic pile, sets the output power P of the galvanic pile as follow-up power meeting the conditions of the galvanic pile, and takes the output power P of the galvanic pile as the input of a closed loop system for follow-up control, thereby ensuring that the change of the state of charge is more gradual, effectively prolonging the service life of the power cell and the fuel cell, and improving the comprehensive endurance capacity.)

1. A fuel cell vehicle energy distribution method is characterized by comprising the following steps:

step S1: collecting a voltage value SOC of a power battery charge state, a pile variable load capacity P, a motor or vehicle power demand P1 and a current pile output power P2;

step S2: judging whether the SOC is greater than a preset voltage upper limit value U2, and if so, finally setting the output power P of the electric pile to be 0; if not, executing the next step;

step S3: judging whether | P2-P1| is greater than or equal to P, and if so, finally setting the electric pile output power P to be P2; if not, the electric pile output power P is set to be (P1+ P2)/2.

Step S4: and taking the obtained output power P of the galvanic pile as an input given value of a closed-loop follow-up system to reasonably distribute system energy.

2. The fuel cell vehicle power distribution method of claim 1, wherein the closed loop servo system in step S4 is operated for a fixed period of time and then the step S1 is restarted.

3. The fuel cell vehicle-mounted energy distribution method according to claim 1, wherein the step S3 further includes, after setting the stack output power P-2 (P1+ P2), determining whether P is greater than 0, and if so, finally setting P-P; if not, setting P as-P finally.

4. The fuel cell vehicle energy distribution method according to claim 1, wherein the fuel cell vehicle energy distribution method is applied to a hybrid power system of a fuel cell.

5. The fuel cell vehicle integrated energy distribution method according to claim 1, wherein the fuel cell vehicle integrated energy distribution method is operated in a vehicle integrated controller VCU or a fuel cell control unit FCU.

6. A fuel cell vehicle power distribution system, comprising:

at least one processor; and at least one memory communicatively coupled to the processor, wherein:

the memory stores program instructions executable by the processor, and the processor calls the program instructions to execute the fuel cell vehicle energy distribution method according to any one of claims 1 to 4.

7. A non-transitory computer-readable storage medium storing computer instructions for causing a computer to perform the fuel cell vehicle energy distribution method according to any one of claims 1 to 4.

Technical Field

The invention belongs to the technical field of energy control of new energy vehicles, and particularly relates to a method for distributing energy of a whole vehicle to fuel cells.

Background

At present, the complete vehicle power system based on the hydrogen fuel cell is roughly divided into two types: full power and hybrid. The full-power form requires synchronous output of the galvanic pile and the power demand of the whole vehicle, and the compound type allows the galvanic pile to output at a constant power point for a long time, so that the demand on the output capacity of the galvanic pile is lower compared with the former. The typical full-power system represents a Toyota mirai vehicle type, the variable load capacity of a galvanic pile reaches over 100kW/s, and the variable load capacity cannot synchronously follow the power capacity of the whole vehicle in China due to the technical difference of the galvanic pile, so that the typical full-power system is a composite power system.

Obviously, the constant-power output mode of the composite power system is beneficial to prolonging the service life of the galvanic pile, but the single output mode is not matched with the complex finished vehicle working condition, so that the loss in the power distribution process is caused, for example, the galvanic pile is in a battery charging working condition, rather than directly providing power for the vehicle, the secondary distribution of energy can be understood, and the actual efficiency is lower than that of the full-power mode. On the one hand, because fuel cell vehicles of other manufacturers set a given required power in an open-loop manner, and on the other hand, the given power is relatively fixed, which results in an unreasonable energy distribution.

Therefore, aiming at the problems of single energy distribution mode and low efficiency of a fuel cell vehicle, an energy distribution solution is urgently needed to be provided, and the energy efficiency in the energy distribution process is improved and the economy of the whole vehicle is improved by actually combining the variable load capacity of the domestic electric pile.

Disclosure of Invention

Technical problem to be solved

The invention provides a fuel cell whole vehicle energy distribution method which can improve the synchronous matching condition of a fuel cell output mode and the whole vehicle working condition, can improve the actual efficiency in the energy distribution process and effectively improve the whole vehicle economy and cruising ability.

(II) technical scheme

The invention also discloses a fuel cell whole vehicle energy distribution method, which comprises the following steps:

step S1: collecting a voltage value SOC of a power battery charge state, a pile variable load capacity P, a motor or vehicle power demand P1 and a current pile output power P2;

step S2: judging whether the SOC is greater than a preset voltage upper limit value U2, and if so, finally setting the output power P of the electric pile to be 0; if not, executing the next step;

step S3: judging whether | P2-P1| is greater than or equal to P, and if so, finally setting the electric pile output power P to be P2; if not, the electric pile output power P is set to be (P1+ P2)/2.

Step S4: and taking the obtained output power P of the galvanic pile as an input given value of a closed-loop follow-up system to reasonably distribute system energy.

Preferably, the closed loop servo-actuated system in step S4 is operated for a fixed time and then the step S1 is executed again.

Preferably, step S3 further includes, after setting the stack output power P to (P1+ P2)/2, determining whether P is greater than 0, and if so, finally setting P to P; if not, setting P as-P finally.

Preferably, the fuel cell vehicle energy distribution method is applied to a fuel cell composite power system.

Preferably, the fuel cell vehicle energy distribution method is operated in a vehicle control unit VCU or a fuel cell control unit FCU.

In another aspect, the present invention also discloses a fuel cell vehicle energy distribution system, including:

at least one processor; and at least one memory communicatively coupled to the processor, wherein:

the memory stores program instructions executable by the processor, and the processor calls the program instructions to execute the fuel cell vehicle energy distribution method according to any one of the above.

In another aspect, the present disclosure also discloses a non-transitory computer-readable storage medium storing computer instructions that cause the computer to perform the fuel cell vehicle energy distribution method according to any one of the above aspects.

(III) advantageous effects

1) The energy distribution method takes power requirements of a power battery, a pile and a whole vehicle as input quantities, main parameters are SOC, pile variable load capacity P, motor or whole vehicle power requirement P1 and current pile output power P2, pile output power P is set as follow-up power meeting pile conditions, and pile output power P is used as input of a closed-loop system for follow-up control, so that the change of the state of charge is more gradual, and the service life and the cruising ability of the battery are effectively improved.

2) The energy distribution method considers the variable load capacity of the galvanic pile and the energy of the battery, considers the output power P2 of the galvanic pile at the last moment of the galvanic pile and the current requirement P1 of the whole vehicle, reasonably distributes the energy of the system and couples, has small integral calculation amount, does not need any hardware improvement and has low cost.

3) The energy distribution method is particularly suitable for a composite power system, the times of calculating the average values of P1 and P2 can be adaptively increased and decreased according to the variable load capacity P of the electric pile, so that different power average values P with different quantities can be effectively calculated for different power systems, the condition during energy recovery (namely P is-P) is also considered, and finally energy can be more reasonably distributed and controlled through a closed-loop follow-up control system.

Drawings

In order to more clearly illustrate the technical solutions of the present invention or the prior art, the drawings needed for the description of the embodiments or the prior art will be briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts:

FIG. 1 is a flow diagram of a prior art open loop control method of an energy management strategy;

FIG. 2 is a flow chart of a fuel cell vehicle energy distribution method of the present invention;

FIG. 3 is a waveform diagram of actual operational data for a prior art open loop control method; the abscissa unit in fig. 3 is time s, the ordinate represents different units corresponding to different variables RANGE, P, and SOC, the mileage RANGE is km in the ordinate unit, P in the ordinate unit is KW, and SOC in the ordinate unit is% in percentage%.

Fig. 4 is a waveform diagram of actual operation data of the energy distribution method of the present invention, where the abscissa unit in fig. 4 is time s, the ordinate represents different units corresponding to different variables Range, P, and SOC, the ordinate unit of the mileage Range is km, the ordinate unit of P is KW, and the ordinate unit of SOC is% in the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings, and it is obvious that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

As shown in fig. 1, in a fuel cell vehicle in the prior art, a given required power is set in an open-loop manner, a state SOC of a power battery is used as an input quantity, main parameters are a battery state of charge SOC and a cell temperature T, so that a fixed stack output power P is set to three gears, and open-loop control of the stack output power P is performed, where the three gears of the stack output power P are respectively P1/P2/P3, a power setting value P1 < P2 < P3, P1/P2/P3 sequentially represent open-loop given powers of a low gear, a middle gear, and a high gear, a voltage upper and lower limit setting value U1 < U2, U1/U2 are respectively a battery voltage lower limit value and a battery upper limit value, a cell temperature upper and lower limit setting value T1 < T2, and T1/T2 are respectively a cell temperature lower limit value and an upper limit value.

The open-loop control method in the prior art shown in fig. 1 determines the gear of the output power by taking the SOC voltage and the cell temperature as judgment conditions to directly allocate energy, but the inventor knows from multiple practical observations and operation experiences that for a complex compound power system, the output mode of the fuel cell cannot be synchronously matched with the working condition of the whole vehicle, the actual efficiency of the energy forced allocation process is not high, the economy of the whole vehicle is low, and the open-loop control based on a fixed given value also affects the service life of the state of the power cell.

In the method, the output power P of the electric pile is used as an input given value of a closed-loop follow-up control system, the power requirements of a power battery, the electric pile and the whole vehicle are used as input quantities, main parameters are SOC, the load variation capacity P of the electric pile (namely the peak power of the electric pile, for example, the load variation capacity P of the electric pile of the full-power Toyota mirai in the background technology is more than 100KW/s, and the load variation capacity P of the electric pile of the domestic general dozens of kW/s), the power requirement P1 of a motor or the whole vehicle and the current output power P2 of the electric pile, and the output power P of the electric pile is set to be the follow-up power meeting the conditions of the electric pile according to the variables.

As shown in fig. 2, the fuel cell vehicle energy distribution method specifically includes the following steps:

step S1: collecting a voltage value SOC of a power battery charge state, a pile variable load capacity P, a motor or vehicle power demand P1 and a current pile output power P2;

step S2: judging whether the SOC is greater than a preset voltage upper limit value U2, and if so, finally setting the output power P of the electric pile to be 0; if not, executing the next step;

step S3: judging whether | P2-P1| is greater than or equal to P, and if so, finally setting the electric pile output power P to be P2; if not, the electric pile output power P is set to be (P1+ P2)/2.

Step S4: and taking the obtained output power P of the galvanic pile as an input given value of a closed-loop follow-up system to reasonably distribute system energy.

Further, in step S4, each phase runs the above steps S1-S4 for a fixed period of time, that is, after the output power P of the cell stack is determined, at least the given value needs to be operated in the closed-loop follow-up system for a fixed period of time to gradually obtain the corresponding power control effect, and then P is updated in real time. And since the value of P varies over time (based primarily on the variation of the mean values of P1 and P2), a closed-loop system needs to be a follow-up system, which is called a follow-up system in a control system if a given input signal is unknown in advance and varies over time and the output of the system varies with the input.

Further, in order to recover and distribute the energy during braking and the like, step S3 further includes, after setting the stack output power P to (P1+ P2)/2, determining whether P is greater than 0, and if so, finally setting P to P (i.e., keeping the same); if not, setting P as-P finally.

Therefore, the algorithm considers the variable load capacity and the battery energy of the electric pile, considers the output P2 of the electric pile at the last moment and the current vehicle demand P1, and reasonably distributes the system energy for coupling.

In order to more intuitively embody the economy of the method, a simulink tool is utilized to construct a model for simulation verification, the parameters of the galvanic pile and the battery in the model are actual operation data of the product, the operation working condition is an NEDC cycle (new European cycle test), and the results are as follows:

algorithm 1 (corresponding to the method of fig. 1): initial state, battery SOC 20%, mH₂6kg, off state SOC 10%, mH₂The total running time T is 6.75h and the total mileage is 272km under 0.9 kg;

algorithm 2 (corresponding to the method of the invention): initial state, battery SOC 20%, mH₂6kg, off state SOC 10%, mH₂The total running time T is 7.45h and the total mileage is 301km, which is 0.9 kg.

Comparing the operation data of fig. 3 and fig. 4, it can be known that the method of the present invention can directly improve the operation time and the mileage by more than 10%, more reasonably distribute energy by using the characteristics and variables of the parts to the maximum extent, further reduce energy consumption, and more smoothly change the state of charge, thereby improving the service life of the battery and the vehicle endurance.

The fuel cell vehicle-mounted energy distribution method of the present invention may be implemented as a software program or computer instructions in a non-transitory computer-readable storage medium or in a control system with a memory and a processor, which may preferably be the vehicle control unit VCU or the fuel cell control unit FCU, and which has a simple and fast running computing program. Each functional unit in the embodiments of the present invention may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit. The integrated unit can be realized in a form of hardware, or in a form of hardware plus a software functional unit. The integrated unit implemented in the form of a software functional unit may be stored in a computer readable storage medium. The software functional unit is stored in a storage medium and includes several instructions to enable a computer device (which may be a personal computer, a server, or a network device) or a processor (processor) to execute some steps of the methods according to the embodiments of the present invention. And the aforementioned storage medium includes: various media capable of storing program codes, such as a usb disk, a removable hard disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk, or an optical disk.

Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.