阅读说明：本技术 一种新能源商用车燃料电池功率分配方法及系统 (Fuel cell power distribution method and system for new energy commercial vehicle ) 是由 单志文 郝兴斌 刘燕 陈厚吉 符萍 李成 王亮 刘帮强 于 2021-08-16 设计创作，主要内容包括：本申请涉及一种新能源商用车燃料电池功率分配方法及系统,属于纯电动商用车技术领域,该方法包括以下步骤：确定燃料电池的功率,并将燃料电池的功率由大到小或由小到大划分为N个功率点,N为≥2的正整数；根据燃料电池的功率点个数,将动力电池的SOC划分为N段SOC参考区间,以分别对应匹配燃料电池的N个功率点；在N段SOC参考区间之间均设置区间回差,若SOC的变化量小于区间回差,则燃料电池的功率点不变,若SOC的变化量大于区间回差,则燃料电池的功率点调整为对应匹配的SOC参考区间。本申请通过保持燃料电池输出功率的相对稳定,以动力电池功率进行削峰平谷,提高燃料电池在电动汽车上的使用寿命,降低了售后维护成本。(The application relates to a method and a system for distributing power of a fuel cell of a new energy commercial vehicle, belonging to the technical field of pure electric commercial vehicles, and the method comprises the following steps: determining the power of the fuel cell, and dividing the power of the fuel cell into N power points from large to small or from small to large, wherein N is a positive integer more than or equal to 2; dividing the SOC of the power battery into N sections of SOC reference intervals according to the number of the power points of the fuel battery so as to respectively and correspondingly match the N power points of the fuel battery; and setting interval return differences among the N sections of SOC reference intervals, if the variation of the SOC is smaller than the interval return differences, keeping the power point of the fuel cell unchanged, and if the variation of the SOC is larger than the interval return differences, adjusting the power point of the fuel cell to be the corresponding matched SOC reference interval. This application is through keeping fuel cell output power's relatively stable to power battery power carries out the peak clipping flat valley, improves fuel cell's life on electric automobile, has reduced the after-sale maintenance cost.)

1. A power distribution method for a fuel cell of a new energy commercial vehicle is characterized by comprising the following steps:

determining the power of the fuel cell, and dividing the power of the fuel cell into N power points from large to small or from small to large, wherein N is a positive integer more than or equal to 2;

dividing the SOC of the power battery into N sections of SOC reference intervals according to the number of the power points of the fuel battery so as to respectively and correspondingly match the N power points of the fuel battery;

and setting interval return differences among the N sections of SOC reference intervals, if the variation of the SOC is smaller than the interval return differences, keeping the power point of the fuel cell unchanged, and if the variation of the SOC is larger than the interval return differences, adjusting the power point of the fuel cell to be the corresponding matched SOC reference interval.

2. The power distribution method for the fuel cell of the new energy commercial vehicle according to claim 1, characterized in that:

the power of the fuel cell is adjusted according to the sequence of the power points from large to small or from small to large, and the power limit of the fuel cell is adjusted across the power points.

3. The power distribution method for the fuel cell of the new energy commercial vehicle according to claim 1, characterized in that:

the power of the fuel cell is adjusted and then kept for 30 seconds, and then the next adjustment can be carried out.

4. The power distribution method for the fuel cell of the new energy commercial vehicle according to claim 1, characterized in that:

and setting the interval return difference as 5%, if the variation of the SOC is less than 5%, keeping the power point of the fuel cell unchanged, and if the variation of the SOC is more than 5%, adjusting the power point of the fuel cell to be a corresponding matched SOC reference interval.

5. The power distribution method for the fuel cell of the new energy commercial vehicle according to claim 1, characterized in that:

the power of the fuel cell is 30KW, the power of the fuel cell is divided into 30KW, 20KW, 10KW and 0KW power points from large to small, the SOC reference interval is divided into reference intervals less than 60%, 60% -70%, 70% -85% and more than 85% in sequence,

when the SOC consults the interval for & lt 60%, fuel cell's power is 30KW, when the SOC consults the interval for 60% ~ 70%, fuel cell's power is 20KW, when the SOC consults the interval for 70% ~ 85%, fuel cell's power is 10KW, when the SOC consults the interval for & gt 85%, fuel cell's power is 0 KW.

6. The power distribution method for the fuel cell of the new energy commercial vehicle according to claim 1, characterized in that:

the variation of the SOC comprises an SOC increase amount and an SOC decrease amount, if the SOC increase amount or the SOC decrease amount is smaller than the interval return difference, the power point of the fuel cell is not changed, if the SOC increase amount is larger than the interval return difference, the power point of the fuel cell is decreased, and if the SOC decrease amount is larger than the interval return difference, the power point of the fuel cell is increased.

7. The power distribution method for the fuel cell of the new energy commercial vehicle according to claim 1, characterized in that:

the power battery comprises a feedback working condition and a discharge working condition, when the power battery is in the discharge working condition, the fuel battery and the power battery supply power to the driving motor together, and when the power battery is in the feedback working condition, the fuel battery and the driving motor charge the power battery together.

8. The power distribution method for the fuel cell of the new energy commercial vehicle according to claim 7, characterized in that:

when the power battery is in a discharging working condition, if the power of the fuel battery is not changed, the current discharging power of the power battery changes along with the required power of the driving motor;

when the power battery is in the feedback working condition, if the power of the fuel battery is not changed, the current generating power of the driving motor is changed along with the current charging power of the power battery.

9. A new energy commercial vehicle fuel cell power distribution system, comprising:

the system comprises a fuel cell, a power cell and a vehicle controller, wherein the fuel cell and the power cell are electrically connected with a driving motor, the vehicle controller controls the fuel cell and the driving motor, the vehicle controller determines the power of the fuel cell, divides the power of the fuel cell into N power points from large to small or from small to large, N is a positive integer larger than or equal to 2, and divides the SOC of the power cell into N sections of SOC reference intervals according to the number of the power points of the fuel cell so as to respectively and correspondingly match the N power points of the fuel cell;

and the whole vehicle controller sets interval return difference between the N sections of SOC reference intervals, if the variation of the SOC is smaller than the interval return difference, the power point of the fuel cell is unchanged, and if the variation of the SOC is larger than the interval return difference, the power point of the fuel cell is adjusted to be the corresponding matched SOC reference interval.

10. The fuel cell power distribution system of the new energy commercial vehicle according to claim 9, characterized in that:

the power battery comprises a feedback working condition and a discharge working condition, when the power battery is in the discharge working condition, the fuel battery and the power battery supply power to the driving motor together, and when the power battery is in the feedback working condition, the fuel battery and the driving motor charge the power battery together.

Technical Field

The application relates to the technical field of pure electric commercial vehicles, in particular to a fuel cell power distribution method and system for a new energy commercial vehicle.

Background

At present, automobile electromotion is a mainstream development direction of the global automobile industry, and an industry chain of the pure electric automobile industry is formed initially under the action of policies and capital. The development of the pure electric vehicle is restricted by the pure electric endurance mileage. Compared with an ICE hybrid vehicle, a hydrogen fuel cell is most likely to become a future solution, and the disadvantage of poor low-temperature performance of a pure electric vehicle can be overcome, so that a fuel cell electric vehicle is one of the directions.

The fuel cell vehicle converts chemical energy into electric energy through the fuel cell to provide electric power for the driving motor so as to drive the vehicle to run. At present, the dynamic response of a fuel cell cannot meet the requirement of rapid change of vehicle power, high voltage is required for the internal cleaning operation of the fuel cell when a motor controller is precharged and stopped when a vehicle is started, the fuel cell cannot recover brake feedback energy, the fuel cell cannot rapidly reach the optimal working state at the beginning of starting, and the fuel cell still needs to be matched with a power cell for working based on the reasons.

In the related art, with the development of fuel cell technology, the cost of fuel cell electric automobiles is continuously reduced, and a foundation is laid for commercialization of the fuel cell electric automobiles. The actual working condition of the automobile is complex, and the power of the driving motor is constantly changed, so that the output power of the fuel cell is also constantly changed. Therefore, many current control schemes follow the power following scheme, and the power of the fuel cell is continuously adjusted to meet the power requirement of the whole vehicle. However, due to the chemical reactions of the fuel cell, frequent power changes can cause irreversible damage, reducing the life of the fuel cell.

Disclosure of Invention

The embodiment of the application provides a power distribution method and system for a fuel cell of a new energy commercial vehicle, and aims to solve the problems that frequent power changes of the fuel cell can cause irreversible damage and the service life of the fuel cell is shortened due to chemical reactions of the fuel cell in the related art.

The first aspect of the embodiment of the application provides a power distribution method for a fuel cell of a new energy commercial vehicle, and the method comprises the following steps:

determining the power of the fuel cell, and dividing the power of the fuel cell into N power points from large to small or from small to large, wherein N is a positive integer more than or equal to 2;

dividing the SOC of the power battery into N sections of SOC reference intervals according to the number of the power points of the fuel battery so as to respectively and correspondingly match the N power points of the fuel battery;

and setting interval return differences among the N sections of SOC reference intervals, if the variation of the SOC is smaller than the interval return differences, keeping the power point of the fuel cell unchanged, and if the variation of the SOC is larger than the interval return differences, adjusting the power point of the fuel cell to be the corresponding matched SOC reference interval.

In some embodiments: the power of the fuel cell is adjusted according to the sequence of the power points from large to small or from small to large, and the power limit of the fuel cell is adjusted across the power points.

In some embodiments: the power of the fuel cell is adjusted and then kept for 30 seconds, and then the next adjustment can be carried out.

In some embodiments: and setting the interval return difference as 5%, if the variation of the SOC is less than 5%, keeping the power point of the fuel cell unchanged, and if the variation of the SOC is more than 5%, adjusting the power point of the fuel cell to be a corresponding matched SOC reference interval.

In some embodiments: the power of the fuel cell is 30KW, the power of the fuel cell is divided into 30KW, 20KW, 10KW and 0KW power points from large to small, the SOC reference interval is divided into reference intervals less than 60%, 60% -70%, 70% -85% and more than 85% in sequence,

when the SOC consults the interval for & lt 60%, fuel cell's power is 30KW, when the SOC consults the interval for 60% ~ 70%, fuel cell's power is 20KW, when the SOC consults the interval for 70% ~ 85%, fuel cell's power is 10KW, when the SOC consults the interval for & gt 85%, fuel cell's power is 0 KW.

In some embodiments: the variation of the SOC comprises an SOC increase amount and an SOC decrease amount, if the SOC increase amount or the SOC decrease amount is smaller than the interval return difference, the power point of the fuel cell is not changed, if the SOC increase amount is larger than the interval return difference, the power point of the fuel cell is decreased, and if the SOC decrease amount is larger than the interval return difference, the power point of the fuel cell is increased.

In some embodiments: the power battery comprises a feedback working condition and a discharge working condition, when the power battery is in the discharge working condition, the fuel battery and the power battery supply power to the driving motor together, and when the power battery is in the feedback working condition, the fuel battery and the driving motor charge the power battery together.

In some embodiments: when the power battery is in a discharging working condition, if the power of the fuel battery is not changed, the current discharging power of the power battery changes along with the required power of the driving motor;

when the power battery is in the feedback working condition, if the power of the fuel battery is not changed, the current generating power of the driving motor is changed along with the current charging power of the power battery.

The second aspect of the embodiment of the present application provides a new energy commercial vehicle fuel cell power distribution system, including:

the system comprises a fuel cell, a power cell and a vehicle controller, wherein the fuel cell and the power cell are electrically connected with a driving motor, the vehicle controller controls the fuel cell and the driving motor, the vehicle controller determines the power of the fuel cell, divides the power of the fuel cell into N power points from large to small or from small to large, N is a positive integer larger than or equal to 2, and divides the SOC of the power cell into N sections of SOC reference intervals according to the number of the power points of the fuel cell so as to respectively and correspondingly match the N power points of the fuel cell;

and the whole vehicle controller sets interval return difference between the N sections of SOC reference intervals, if the variation of the SOC is smaller than the interval return difference, the power point of the fuel cell is unchanged, and if the variation of the SOC is larger than the interval return difference, the power point of the fuel cell is adjusted to be the corresponding matched SOC reference interval.

In some embodiments: the power battery comprises a feedback working condition and a discharge working condition, when the power battery is in the discharge working condition, the fuel battery and the power battery supply power to the driving motor together, and when the power battery is in the feedback working condition, the fuel battery and the driving motor charge the power battery together.

The beneficial effect that technical scheme that this application provided brought includes:

the embodiment of the application provides a power distribution method and a system for a fuel cell of a new energy commercial vehicle, the power distribution method for the fuel cell of the new energy commercial vehicle firstly determines the power of the fuel cell, and divides the power of the fuel cell into N power points from large to small or from small to large, wherein N is a positive integer which is more than or equal to 2; secondly, dividing the SOC of the power battery into N sections of SOC reference intervals according to the number of the power points of the fuel battery so as to respectively and correspondingly match the N power points of the fuel battery; and finally, interval return differences are set between the N sections of SOC reference intervals, if the variation of the SOC is smaller than the interval return differences, the power point of the fuel cell is unchanged, and if the variation of the SOC is larger than the interval return differences, the power point of the fuel cell is adjusted to be the corresponding matched SOC reference interval.

Therefore, according to the new energy commercial vehicle fuel cell power distribution method, the power of the fuel cell is divided into N power points from large to small or from small to large, then the SOC of the power cell is divided into N sections of SOC reference intervals according to the number of the power points of the fuel cell, finally, interval return differences are set between the N sections of SOC reference intervals, and if the variation of the SOC is smaller than the interval return differences, the power points of the fuel cell are unchanged. The power of the fuel cell is used as basic power, the required power of the power cell during discharging is balanced, and the charging power of the power cell during power generation is balanced by the driving motor. By keeping the output power of the fuel cell relatively stable and performing peak clipping and valley flattening by the power of the power cell, the service life of the fuel cell on the electric automobile is prolonged, and the after-sale maintenance cost is reduced.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

Fig. 1 is a schematic structural diagram of a discharge condition of a power battery according to an embodiment of the present application;

fig. 2 is a schematic structural diagram of feedback conditions of a power battery according to an embodiment of the present application.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are some embodiments of the present application, but not all embodiments. 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 application.

The embodiment of the application provides a power distribution method and a power distribution system for a fuel cell of a new energy commercial vehicle, which can solve the problems that frequent power changes of the fuel cell can generate irreversible damage and the service life of the fuel cell is shortened due to chemical reactions of the fuel cell in the related technology.

The first aspect of the embodiment of the application provides a power distribution method for a fuel cell of a new energy commercial vehicle, and the method comprises the following steps:

step 1, determining the power of a fuel cell, and dividing the power of the fuel cell into N power points from large to small or from small to large, wherein N is a positive integer more than or equal to 2; the embodiment of the application takes the power of a fuel cell as 30KW as an example, and the power of the fuel cell with 30KW is divided into four power points of 30KW, 20KW, 10KW and 0KW from large to small in sequence.

Step 2, dividing the SOC of the power battery into N sections of SOC reference intervals according to the number of the power points of the fuel battery so as to respectively and correspondingly match the N power points of the fuel battery; in the embodiment of the application, the SOC reference interval is divided into four reference intervals which are less than 60%, 60% -70%, 70% -85% and more than 85% in sequence;

when the SOC consults the interval for & lt 60%, fuel cell's power is 30KW, when the SOC consults the interval for 60% ~ 70%, fuel cell's power is 20KW, when the SOC consults the interval for 70% ~ 85%, fuel cell's power is 10KW, when the SOC consults the interval for & gt 85%, fuel cell's power is 0 KW.

Step 3, interval return difference is set between N sections of SOC reference intervals, if the variation of the SOC is smaller than the interval return difference, the power point of the fuel cell is unchanged, and if the variation of the SOC is larger than the interval return difference, the power point of the fuel cell is adjusted to be the corresponding matched SOC reference interval; the interval return difference setting of the embodiment of the present application is preferably, but not limited to, 5%, and if the variation of the SOC is less than 5%, the power point of the fuel cell is not changed, and if the variation of the SOC is greater than 5%, the power point of the fuel cell is adjusted to correspond to the matching SOC reference interval.

According to the fuel cell power distribution method for the new energy commercial vehicle, the power of the fuel cell is divided into N power points from large to small or from small to large, then the SOC of the power cell is divided into N sections of SOC reference intervals according to the number of the power points of the fuel cell, finally interval return differences are set between the N sections of SOC reference intervals, and if the variation of the SOC is smaller than the interval return differences, the power points of the fuel cell are kept unchanged. The power of the fuel cell is used as basic power, the required power of the power cell during discharging is balanced, and the charging power of the power cell during power generation is balanced by the driving motor. By keeping the output power of the fuel cell relatively stable and performing peak clipping and valley flattening by the power of the power cell, the service life of the fuel cell on the electric automobile is prolonged, and the after-sale maintenance cost is reduced.

In some alternative embodiments: the embodiment of the application provides a power distribution method for a fuel cell of a new energy commercial vehicle, the power of the fuel cell of the power distribution method for the fuel cell of the new energy commercial vehicle is adjusted from large to small or from small to large according to the size of power points, the power limit of the fuel cell is adjusted across the power points, and the power of the fuel cell is kept for 30 seconds after being adjusted, so that the next adjustment can be carried out.

The power of the fuel cell is strictly adjusted according to the sequence of the power points from large to small or from small to large, the power of the fuel cell is kept for 30 seconds at least after adjustment, the power of the fuel cell is not allowed to jump across the power points, the power fluctuation of the fuel cell is reduced as much as possible, and the service life of the fuel cell on the electric automobile is prolonged.

In some alternative embodiments: the embodiment of the application provides a new energy commercial vehicle fuel cell power distribution method, wherein the variation of SOC of the new energy commercial vehicle fuel cell power distribution method comprises an SOC (state of charge) increasing amount and an SOC reducing amount, if the SOC increasing amount or the SOC reducing amount is smaller than 5% interval return difference, a power point of a fuel cell is unchanged, if the SOC increasing amount is larger than 5% interval return difference, a power point of the fuel cell is reduced, and if the SOC reducing amount is larger than 5% interval return difference, the power point of the fuel cell is increased.

Assuming that the SOC is 62% at vehicle power-on, the fuel cell target power is 20 kw. At this time, the power command of the fuel cell should be set at 10kw, and the power of the fuel cell should be increased to 20kw after 30 seconds. If the vehicle SOC rises to 75%, the fuel cell power drops to 10 kw. If the vehicle SOC continues to drop to 55%, the fuel cell power rises to 30kw until SOC rises to 65% and the fuel cell power falls back to 20 kw.

In some alternative embodiments: the embodiment of the application provides a power distribution method for a fuel cell of a new energy commercial vehicle, wherein the power cell of the power distribution method for the fuel cell of the new energy commercial vehicle comprises a feedback working condition and a discharge working condition, when the power cell is in the discharge working condition, the fuel cell and the power cell supply power to a driving motor together, and when the power cell is in the feedback working condition, the fuel cell and the driving motor charge the power cell together.

When the power battery is in a discharging working condition, if the power of the fuel battery is not changed, the current discharging power of the power battery changes along with the required power of the driving motor; when the power battery is in the feedback working condition, if the power of the fuel battery is not changed, the current generating power of the driving motor is changed along with the current charging power of the power battery.

According to the characteristic that the motor of the electric automobile can be driven and fed back, the following power balance equation is provided:

and (3) discharge working condition:

P_F+P_DB＝P_DM+P_A

in the formula, P_FRepresenting the output power, P, of the fuel cell_DBRepresenting the current discharge power, P, of the power battery_DMRepresenting the power demand of the drive motor, P_ARepresents the power demand of other accessories on the vehicle, when P_AAnd may be ignored when accessory power is low.

The power generation working condition is as follows:

P_CB＝P_CM+P_F

in the formula, P_FRepresenting the output power, P, of the fuel cell_CBRepresenting the current charging power, P, of the power battery_CMRepresenting the generated power of the drive motor.

Referring to fig. 1 and 2, a second aspect of the embodiments of the present application provides a fuel cell power distribution system for a new energy commercial vehicle, including:

the vehicle control unit determines the power of the fuel cell, divides the power of the fuel cell into N power points from large to small or from small to large, wherein N is a positive integer larger than or equal to 2, and divides the SOC of the power cell into N sections of SOC reference intervals according to the number of the power points of the fuel cell so as to respectively and correspondingly match the N power points of the fuel cell.

And the vehicle control unit sets interval return difference between the N sections of SOC reference intervals, if the variation of the SOC is smaller than the interval return difference, the power point of the fuel cell is unchanged, and if the variation of the SOC is larger than the interval return difference, the power point of the fuel cell is adjusted to be the corresponding matched SOC reference interval.

The power battery comprises a feedback working condition and a discharge working condition, when the power battery is in the discharge working condition, the fuel battery and the power battery supply power to the driving motor together, and when the power battery is in the feedback working condition, the fuel battery and the driving motor charge the power battery together.

Principle of operation

The embodiment of the application provides a power distribution method and a system for a fuel cell of a new energy commercial vehicle, the power distribution method for the fuel cell of the new energy commercial vehicle firstly determines the power of the fuel cell, and divides the power of the fuel cell into N power points from large to small or from small to large, wherein N is a positive integer which is more than or equal to 2; secondly, dividing the SOC of the power battery into N sections of SOC reference intervals according to the number of the power points of the fuel battery so as to respectively and correspondingly match the N power points of the fuel battery; and finally, interval return differences are set between the N sections of SOC reference intervals, if the variation of the SOC is smaller than the interval return differences, the power point of the fuel cell is unchanged, and if the variation of the SOC is larger than the interval return differences, the power point of the fuel cell is adjusted to be the corresponding matched SOC reference interval.

Therefore, according to the new energy commercial vehicle fuel cell power distribution method, the power of the fuel cell is divided into N power points from large to small or from small to large, then the SOC of the power cell is divided into N sections of SOC reference intervals according to the number of the power points of the fuel cell, finally, interval return differences are set between the N sections of SOC reference intervals, and if the variation of the SOC is smaller than the interval return differences, the power points of the fuel cell are unchanged. The power of the fuel cell is used as basic power, the required power of the power cell during discharging is balanced, and the charging power of the power cell during power generation is balanced by the driving motor. By keeping the output power of the fuel cell relatively stable and performing peak clipping and valley flattening by the power of the power cell, the service life of the fuel cell on the electric automobile is prolonged, and the after-sale maintenance cost is reduced.

In the description of the present application, it should be noted that the terms "upper", "lower", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, which are only for convenience in describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and operate, and thus, should not be construed as limiting the present application. Unless expressly stated or limited otherwise, the terms "mounted," "connected," and "connected" are intended to be inclusive and mean, for example, that they may be fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art as appropriate.

It is noted that, in the present application, relational terms such as "first" and "second", and the like, are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.

The above description is merely exemplary of the present application and is presented to enable those skilled in the art to understand and practice the present application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the application. Thus, the present application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.