阅读说明：本技术 一种燃料电池系统的功率控制方法 (Power control method of fuel cell system ) 是由 赵兴旺 张国强 杨绍军 贾能铀 张禾 于 2020-03-19 设计创作，主要内容包括：本发明提供了一种燃料电池系统的功率控制方法,包括：燃料电池系统启动；判断燃料电池系统是否处于运行状态,若“是”获取乘车需求功率P<Sub>req</Sub>；根据预先得到功率-电流关系求得目标电流I<Sub>req</Sub>并使燃料电池的输出电流I<Sub>out</Sub>等于目标电流I<Sub>req</Sub>；获取燃料电池的实际输出功率P<Sub>o</Sub>并判断实际输出功率是否处于稳态,若“是”计算功率偏差并判断率偏差ΔP＝P<Sub>req</Sub>-P<Sub>o</Sub>是否大于等于预设的阈值P<Sub>t</Sub>,若“是”根据输出电流I<Sub>out</Sub>、需求功率P<Sub>req</Sub>和功率偏差ΔP计算电流偏差ΔI；使燃料电池的输出电流等于I<Sub>out</Sub>+ΔI。这种方法的优点在于：不依赖极化曲线的辨识过程对燃料电池电堆的最大净输出功率进行估算,适用于更多的应用场景；不会引起电堆输出电流波动且不会加速电堆的寿命衰减。(The invention provides a power control method of a fuel cell system, which comprises the following steps: starting the fuel cell system; judging whether the fuel cell system is in the running state, if so, acquiring the power P required by the bus req (ii) a Obtaining a target current I according to a pre-obtained power-current relation req And making the output current I of the fuel cell out Equal to the target current I req (ii) a Obtaining the actual output power P of the fuel cell o And judging whether the actual output power is in a steady state, if so, calculating the power deviation and judging the rate deviation delta P to be P req ‑P o Whether the value is greater than or equal to a preset threshold value P t If yes, according to the output current I out Required power P req Calculating a current deviation delta I according to the power deviation delta P; making the output current of the fuel cell equal to I out + Δ I. The advantages of this method are: the maximum net output power of the fuel cell stack is estimated in the identification process independent of the polarization curve, so that the method is suitable for more application scenes; the output current fluctuation of the electric pile can not be caused, and the life attenuation of the electric pile can not be accelerated.)

1. A power control method of a fuel cell system, characterized by comprising a plurality of steps of:

step 1: the fuel cell system starts and sets k to 0;

step 2: judging whether the fuel cell system is in the running state, if so, executing the step 3;

and step 3: obtaining the riding required power P_req；

And 4, step 4: obtaining a target current I according to a pre-obtained power-current relation_reqAnd making the output current I of the fuel cell_outEqual to the target current I_req；

And 5: obtaining the actual output power P of the fuel cell_oJudging whether the actual output power is in a stable state, if so, executing the step 6;

step 6: calculating power deviation Δ P ═ P_req-P_oAnd judging whether the rate deviation delta P is greater than or equal to a preset threshold value P_tIf yes, executing step 7; if not, executing the step 2 again;

and 7: according to the output current I_outRequired power P_reqCalculating a current deviation delta I according to the power deviation delta P;

and 8: making the output current of the fuel cell equal to I_out+ Δ I and setting k to 1, then step 5 is performed again.

2. The power control method of a fuel cell system according to claim 1, wherein the step 2: and judging whether the fuel cell system is in the running state, and if not, ending the processing.

3. The power control method of a fuel cell system according to claim 2, characterized in that the step 7: according to the output current I_oRequired power P_reqAnd the power deviation Δ P to calculate the current deviation Δ I by the formula:

wherein C is a correction coefficient.

4. Such as rightThe power control method of a fuel cell system according to claim 3, wherein the judging whether the output power is in a steady state is a judging of a required power P within a predetermined time period_reqAnd the actual power P₀Whether the difference between the maximum value and the minimum value of the two are all smaller than a preset threshold value P_max。

5. The power control method of a fuel cell system according to claim 4, wherein the step 5: obtaining the actual output power P of the fuel cell_oJudging whether the actual output power is in a stable state, if not, executing the step 9;

and step 9: judging whether k is not 0, if yes, executing step 10; if not, executing the step 2 again;

step 10: according to the actual output power P_oAnd an output current I_outThe power-current relationship and/or the voltage-current relationship is updated, k is set to 0 and the stack decay rate is calculated, and then step 2 is performed again.

6. The power control method of a fuel cell system according to claim 5, wherein the power-current relationship is a power-current MAP, a fitted equation between power and current, or a theoretical equation between power and current.

7. The power control method of a fuel cell system according to claim 5, wherein the voltage-current relationship is a voltage-current MAP, a fitted equation between voltage and current, or a theoretical equation between voltage and current.

Technical Field

The invention relates to the field of fuel cell vehicle control, in particular to a power control method of a fuel cell system.

Background

The hydrogen fuel cell is a power generation device which directly converts chemical energy generated by the reaction of hydrogen and oxygen into electric energy through electrochemical reaction, has the advantages of high power generation efficiency, small environmental pollution and the like, and is widely applied to the field of automobiles. The proton exchange membrane fuel cell has the working principle that hydrogen and oxygen generate electrochemical reaction to generate water and output electric energy at the same time. Because the voltage of the fuel cell is usually less than 1V, in practical application, hundreds of single cells need to be connected in series to form a fuel cell stack and matched with corresponding peripheral accessories to form a fuel cell system.

Because the performance of the fuel cell stack can be continuously attenuated along with the increase of the service time, the efficiency is reduced, and the requirement of a fuel cell automobile on power is difficult to meet, so that the dynamic performance is reduced, the output power of the fuel cell system needs to be subjected to online adaptive control, so that the real-time response of the fuel cell system on the required power of the whole automobile is ensured. However, due to the inherent characteristics of the fuel cell, the wide fluctuation of the output power of the fuel cell will accelerate the decay rate of the performance, so a method of adaptive control needs to be carefully selected to avoid the wide fluctuation of the output power of the fuel cell system.

The prior technical scheme is that a polarization curve of a fuel cell stack is estimated (an algorithm for estimating an online self-adaptive polarization curve of the fuel cell stack, a general automobile global technology operation company, with a publication number of CN 101237064B; a method and a system for calculating the maximum net power of a fuel cell system based on polarization curve estimation, with a publication number of CN101533073B, as above), and the series of patents provide a method for identifying the polarization curve on line based on a theoretical model, and estimate the maximum net output power of the stack on the basis of the method, so as to realize power control after the stack is attenuated. However, in the implementation process of the method, due to the identification process depending on the polarization curve, the process has the problem of insufficient data collection, which can lead to the failure of the implementation of the subsequent steps and the failure of the adaptive power control during the data collection.

In view of the foregoing, it is desirable to provide a power control method for a fuel cell system that overcomes the deficiencies of the prior art.

Disclosure of Invention

The present invention is directed to a power control method of a fuel cell system that overcomes the disadvantages of the prior art. The object of the present invention is achieved by the following technical means.

One embodiment of the present invention provides a power control method of a fuel cell system, wherein the power control method of the fuel cell system includes a plurality of steps of:

step 1: the fuel cell system starts and sets k to 0;

step 2: judging whether the fuel cell system is in the running state, if so, executing the step 3;

and step 3: obtaining the riding required power P_req；

And 4, step 4: obtaining a target current I according to a pre-obtained power-current relation_reqAnd making the output current I of the fuel cell_outEqual to the target current I_req；

And 5: obtaining the actual output power P of the fuel cell_oJudging whether the actual output power is in a stable state, if so, executing the step 6;

step 6: calculating power deviation Δ P ═ P_req-P_oAnd judging whether the rate deviation delta P is greater than or equal to a preset threshold value P_tIf yes, executing step 7; if not, executing the step 2 again;

and 7: according to the output current I_outRequired power P_reqCalculating a current deviation delta I according to the power deviation delta P;

and 8: making the output current of the fuel cell equal to I_out+ Δ I and setting k to 1, then step 5 is performed again.

According to the power control method of the fuel cell system provided by the above-described one embodiment of the present invention, the step 2: and judging whether the fuel cell system is in the running state, and if not, ending the processing.

According to the power control method of the fuel cell system provided in the above-described one embodiment of the present invention, the step 7: according to the output current I_oRequired power P_reqAnd the power deviation Δ P to calculate the current deviation Δ I by the formula:

wherein C is a correction coefficient.

According to the power control method of the fuel cell system provided by the above-mentioned one embodiment of the present invention, the judging whether the output power is in the steady state is to judge the required power P within a preset time period_reqAnd the actual power P₀Whether the difference between the maximum value and the minimum value of the two are all smaller than a preset threshold value P_max。

According to the power control method of the fuel cell system provided in the above-described one embodiment of the present invention, the step 5: obtaining the actual output power P of the fuel cell_oJudging whether the actual output power is in a stable state, if not, executing the step 9;

and step 9: judging whether k is not 0, if yes, executing step 10; if not, executing the step 2 again;

step 10: according to the actual output power P_oAnd an output current I_outUpdating the power-current relation and/or the voltage-current relation, setting k to be 0, calculating the attenuation rate of the galvanic pile, and then executing the step 2 again;

the power control method of a fuel cell system according to the above-described one embodiment of the present invention is provided, wherein the power-current relationship is a power-current MAP, a fitted equation between power-current, or a theoretical equation between power-current.

The power control method of a fuel cell system according to the above-described one embodiment of the present invention is provided, wherein the voltage-current relationship is a voltage-current MAP, a fitted equation between voltage and current, or a theoretical equation between voltage and current.

The power control method of the fuel cell system has the advantages that: the maximum net output power of the fuel cell stack is estimated independent of the identification process of the polarization curve, so that the method is suitable for more application scenes and solves the problems that follow-up steps cannot be implemented and power self-adaptive control cannot be realized during data collection due to insufficient data collection; the output current fluctuation of the electric pile can not be caused, and the life attenuation of the electric pile can not be accelerated; it is possible to avoid occurrence of wide-range fluctuation in the output power of the fuel cell system.

Drawings

The disclosure of the present invention will become more readily understood with reference to the accompanying drawings. As is readily understood by those skilled in the art: these drawings are only for illustrating the technical solutions of the present invention and are not intended to limit the scope of the present invention. In the figure:

fig. 1 shows a flowchart of a power control method of a fuel cell system according to an embodiment of the present invention.

Detailed Description

Fig. 1 and the following description depict alternative embodiments of the invention to teach those skilled in the art how to make and reproduce the invention. Some conventional aspects have been simplified or omitted for the purpose of teaching the present invention. Those skilled in the art will appreciate that variations or substitutions from these embodiments will fall within the scope of the invention. Those skilled in the art will appreciate that the features described below can be combined in various ways to form multiple variations of the invention. Thus, the present invention is not limited to the following alternative embodiments, but is only limited by the claims and their equivalents.

Fig. 1 shows a flowchart of a power control method of a fuel cell system according to an embodiment of the present invention. As shown in fig. 1, the power control method of the fuel cell system includes a plurality of steps of:

step 1: the fuel cell system starts and sets k to 0;

step 2: judging whether the fuel cell system is in the running state, if so, executing the step 3;

and step 3: obtaining the riding required power P_req；

And 4, step 4: obtaining a target current I according to a pre-obtained power-current relation_reqAnd making the output current I of the fuel cell_outEqual to the target current I_req；

And 5: obtaining the actual output power P of the fuel cell_oJudging whether the actual output power is in a stable state, if so, executing the step 6;

step 6: calculating power deviation Δ P ═ P_req-P_oAnd judging whether the rate deviation delta P is greater than or equal to a preset threshold value P_tIf yes, executing step 7; if not, executing the step 2 again;

and 7: according to the output current I_outRequired power P_reqCalculating a current deviation delta I according to the power deviation delta P;

and 8: making the output current of the fuel cell equal to I_out+ Δ I and setting k to 1, then step 5 is performed again.

According to the power control method of the fuel cell system provided by the above-described one embodiment of the present invention, the step 2: and judging whether the fuel cell system is in the running state, and if not, ending the processing.

According to the power control method of the fuel cell system provided in the above-described one embodiment of the present invention, the step 7: according to the output current I_oRequired power P_reqAnd the power deviation Δ P to calculate the current deviation Δ I by the formula:

wherein C is a correction coefficient.

According to the power control method of the fuel cell system provided by the above-mentioned one embodiment of the present invention, the judging whether the output power is in the steady state is to judge the required power P within a preset time period_reqAnd the actual power P₀Whether the difference between the maximum value and the minimum value of the two are all smaller than a preset threshold value P_max。

According to the power control method of the fuel cell system provided in the above-described one embodiment of the present invention, the step 5: obtaining the actual output power P of the fuel cell_oJudging whether the actual output power is in a stable state, if not, executing the step 9;

and step 9: judging whether k is not 0, if yes, executing step 10; if not, executing the step 2 again;

step 10: according to the actual output power P_oAnd an output current I_outUpdating the power-current relation and/or the voltage-current relation, setting k to be 0, calculating the attenuation rate of the galvanic pile, and then executing the step 2 again;

according to the power control method of the fuel cell system according to the above-described embodiment of the present invention, the stack decay rate is calculated, and specifically, the decay rate at a specific current can be simply estimated using the existing method:

the attenuation rate can also be calculated using the voltage-current theoretical formula:

wherein, I_sIs a current, U_estIs calculated according to a theoretical formula I_sVoltage of lower, U_BOLThe voltage value is the voltage value of the electric pile when the electric pile leaves the factory.

The power control method of the fuel cell system according to the above-described one embodiment of the present invention is provided, wherein the power-current relationship is a power-current MAP, a fitted equation between power and current, or a theoretical equation between power and current, such as:

P＝∑a_i·Iⁱ

where P is the stack power, a_iFor the fitting coefficient, I is the current.

The power control method of the fuel cell system according to the above-described one embodiment of the present invention is provided, wherein the voltage-current relationship is a voltage-current MAP, a fitted equation between voltage and current, or a theoretical equation between voltage and current, such as:

U＝f(I)＝a-b·lnI-I·R

wherein U is voltage, a, b and R are fitting coefficients, and I is current.

The power control method of the fuel cell system has the advantages that: the maximum net output power of the fuel cell stack is estimated independent of the identification process of the polarization curve, so that the method is suitable for more application scenes and solves the problems that follow-up steps cannot be implemented and power self-adaptive control cannot be realized during data collection due to insufficient data collection; the output current fluctuation of the electric pile can not be caused, and the life attenuation of the electric pile can not be accelerated; it is possible to avoid occurrence of wide-range fluctuation in the output power of the fuel cell system.

It will of course be realised that whilst the foregoing has been given by way of illustrative example of this invention, all such and other modifications and variations thereto as would be apparent to persons skilled in the art are deemed to fall within the broad scope and ambit of this invention as is herein set forth. Therefore, while this invention has been described with reference to preferred embodiments, it is not intended that the novel apparatus be limited thereby, but on the contrary, it is intended to cover various modifications and equivalent arrangements included within the broad scope of the above disclosure and the appended claims.