Active Disturbance Rejection Control Method for Fuel Cell Electric Air Compressor

Abstract

The present invention discloses an auto-disturbance rejection control method for a fuel cell electric air compressor, which includes the following steps: pre-store the data of the ultra-high speed electric air compressor; obtain the actual speed, actual torque, target speed and target torque of the ultra-high speed electric air compressor in real time, and obtain the target speed and target torque at the next moment according to the working conditions; obtain the corresponding disturbance parameters according to the actual speed and actual torque, denoted as the first disturbance parameter; obtain the corresponding disturbance parameters according to the target speed and target torque at the next moment, denoted as the second disturbance parameter; obtain the first feedback parameter according to the first disturbance parameter and the second disturbance parameter; combine the first feedback parameter with the control parameter of the ultra-high speed electric air compressor and then control the ultra-high speed electric air compressor to pre-eliminate the disturbance at the next moment. The present invention can reduce the fluctuation of the ultra-high speed electric air compressor during high-speed rotation, which is beneficial to improving the power performance of fuel cell vehicles.

Description

Technical Field

[0001] The present invention relates to the technical field of fuel cell vehicles, and in particular to a method for controlling an electric air compressor of a fuel cell. Background Art

[0002] Hydrogen fuel cell vehicles generate energy by releasing electricity through a chemical reaction between hydrogen and oxygen. Their emissions are water, which can truly achieve zero-sequence pollution. It is one of the important directions for the development of new energy vehicles in the future.

[0003] In hydrogen fuel cell vehicles, oxygen is mainly supplied to the fuel cell reactor by real-time compressed air through an air compressor. As a key component of the fuel cell system, in order to meet the air supply demand, the speed requirement for the air compressor is much greater than that of a general air compressor, and the speed usually needs to reach tens of thousands or even more than 100,000 revolutions. Moreover, the air compressor must also work within a wider working range so that the fuel cell stack can meet the vehicle power output requirements of a wide power range under all working conditions, and follow the vehicle power output requirements that change rapidly due to changes in working conditions. It is usually driven by an ultra-high-speed permanent magnet synchronous motor. When the ultra-high-speed electric air compressor rotates at high speed, it will produce violent fluctuations. The elimination of speed fluctuations increases the speed regulation time of the ultra-high-speed electric air compressor, limits the power output of the fuel cell reactor, and seriously affects the power of the fuel cell vehicle. The inducement of violent speed mainly comes from load excitation and electromagnetic excitation.

[0004] How to reduce the fluctuation of ultra-high-speed electric air compressors when they rotate at high speed is one of the important issues to be solved urgently in this field. Summary of the invention

[0005] The purpose of the present invention is to provide a fuel cell electric air compressor self-disturbance control method to solve the deficiencies in the prior art. It can reduce the fluctuation of the ultra-high-speed electric air compressor when rotating at high speed, which is beneficial to improving the power of fuel cell vehicles.

[0006] The present invention provides a method for controlling an electric air compressor of a fuel cell, wherein the electric air compressor is used in a fuel cell vehicle, and the method comprises the following steps:

[0007] Pre-store ultra-high-speed electric air compressor data, including speed, torque and corresponding disturbance parameters;

[0008] Obtain the actual speed, actual torque, target speed and target torque of the ultra-high-speed electric air compressor in real time, and obtain the target speed and target torque at the next moment according to the working conditions;

[0009] Obtain corresponding disturbance parameters according to the actual speed and the actual torque, recorded as the first disturbance parameter;

[0010] Obtain the corresponding disturbance parameter according to the target rotational speed and target torque at the next moment, denoted as the second disturbance parameter;

[0011] Obtain the first feedback parameter according to the first disturbance parameter and the second disturbance parameter;

[0012] Merge the first feedback parameter with the control parameter of the ultra-high speed electric air compressor and then control the ultra-high speed electric air compressor to pre-eliminate the disturbance at the next moment.

[0013] The auto-disturbance rejection control method of the fuel cell electric air compressor as described above, wherein, optionally, obtaining the first feedback parameter includes the following steps,

[0014] Interpolate the disturbance parameters corresponding to between the current rotational speed and the target rotational speed at the next moment, and between the current torque and the target torque at the next moment to obtain a set of rotational speeds, torques and corresponding disturbance parameters;

[0015] Take the disturbance parameter as the first feedback parameter.

[0016] The auto-disturbance rejection control method of the fuel cell electric air compressor as described above, wherein, optionally, it further includes pre-storing data correction;

[0017] Obtain the actual disturbance data at the current moment;

[0018] Cache the actual disturbance data at the current moment corresponding to the actual rotational speed and actual torque at the current moment;

[0019] Judge whether the number of actual disturbance data corresponding to the actual rotational speed and actual torque at the current moment is greater than N, if so, obtain the median of the disturbance data, and use it as the new disturbance parameter to modify the corresponding disturbance parameter in the pre-stored data of the ultra-high speed electric air compressor, and eliminate the first M cached disturbance data; where N is an integer not less than 100, and M is a positive integer not greater than N / 2.

[0020] The auto-disturbance rejection control method of the fuel cell electric air compressor as described above, wherein, optionally, the time interval between the current moment and the next moment is not greater than 1S.

[0021] The auto-disturbance rejection control method of the fuel cell electric air compressor as described above, wherein, optionally, it further includes the following steps,

[0022] Obtain the actual disturbance parameter at the current moment, and cache the actual disturbance parameter at the current moment;

[0023] Judge whether the actual disturbance parameter at the current moment is greater than the set value;

[0024] If the proportion of the disturbance parameters greater than the set value within consecutive S time intervals exceeds 50%, then the second feedback parameter is obtained based on all the actual disturbance parameters obtained within these consecutive S time intervals;

[0025] The second feedback parameter and the first feedback parameter are combined with the control parameters of the ultra-high-speed electric air compressor to control the ultra-high-speed electric air compressor, so as to eliminate the disturbance at the next moment; where S is a positive integer not less than 30.

[0026] For the active disturbance rejection control method of the fuel cell electric air compressor as described above, optionally, the method for obtaining the second feedback parameter is:

[0027] Calculate the average value of all the actual disturbance parameters obtained within these consecutive S time intervals;

[0028] Take this average value as the second feedback parameter.

[0029] For the active disturbance rejection control method of the fuel cell electric air compressor as described above, optionally, the pre-stored ultra-high-speed electric air compressor data further includes rotational acceleration, intake air volume, and intake and exhaust pressure difference.

[0030] Compared with the prior art, the present invention pre-stores the rotational speed, torque, and corresponding disturbance parameters, so as to estimate the disturbance parameters at the next moment during control, thereby pre-adjusting the control parameters at the next moment, and can effectively reduce the disturbance at the next moment.

[0031] As the electric air compressor is used, the corresponding disturbance parameters under different rotational speeds and torques are also changing. In order to adapt to the states of different life stages of the electric air compressor, the present invention also modifies the pre-stored data according to the actually monitored disturbance parameters, so that the pre-stored data can be adapted to the air compressors in different life periods, and ensure that the occurrence of disturbances can be accurately reduced at any life stage. Description of the Drawings

[0032] Figure 1 is the overall step flow chart of the control method proposed by the present invention;

[0033] Figure 2 is the specific step flow chart of step S5 proposed by the present invention;

[0034] Figure 3 is the specific step flow chart for replacing step S6 proposed in Embodiment 2 of the present invention;

[0035] Figure 4 is the specific step flow chart of step S063 proposed in Embodiment 2 of the present invention; Detailed Embodiments

[0036] The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0037] Embodiment 1

[0038] Please refer to Figure 1 and Figure 2 , this embodiment proposes an active disturbance rejection control method for a fuel cell electric air compressor. The electric air compressor is used in a fuel cell vehicle. Specifically, it includes the following steps:

[0039] S1. Pre-store the data of the ultra-high-speed electric air compressor, including the rotational speed, torque, and the corresponding disturbance parameters.

[0040] Specifically, the data of the ultra-high-speed electric air compressor is obtained through a bench test of the ultra-high-speed electric air compressor of the same model without feedback parameters. That is, in the absence of both the first feedback parameter and the second feedback parameter, the disturbance parameters corresponding to different rotational speeds and different torques are obtained through a bench test.

[0041] S2. Real-time obtain the actual rotational speed, actual torque, target rotational speed, and target torque of the ultra-high-speed electric air compressor, and obtain the target rotational speed and target torque at the next moment according to the working condition. Specifically, the target rotational speed and target torque are used to cooperate with the actual rotational speed and actual torque to obtain the corresponding disturbance under the current actual rotational speed and actual torque. Obtaining the target rotational speed and target torque at the next moment is to predict the disturbance at the next moment in advance, so as to correct the control parameters in advance and improve the effect of anti-disturbance control.

[0042] In specific implementation, in order to accurately obtain the target rotational speed and target torque at the next moment, after obtaining the driving intention, plan the change trend of the rotational speed and torque according to the driving intention, and control the vehicle according to this change trend. Specifically, the target rotational speed and target torque at the next moment can be determined according to the change trend of the rotational speed and torque planned according to the driving intention. In implementation, the rotational speed and torque are planned according to the driving intention and adjusted at a set time interval. Specifically, the time interval for planning the rotational speed and torque according to the driving intention is at least twice the time duration between the current moment and the next moment.

[0043] S3. Obtain the corresponding disturbance parameter according to the actual rotational speed and actual torque, denoted as the first disturbance parameter. The first disturbance parameter is one of the important parameters for correcting the control parameters. In implementation, the first disturbance parameter is the corresponding disturbance parameter found from the pre-stored data according to the actual rotational speed and actual torque.

[0044] S4. Obtain the corresponding disturbance parameter according to the target speed and target torque at the next moment, denoted as the second disturbance parameter. During implementation, the second disturbance parameter is the corresponding disturbance parameter found from the pre-stored data according to the target speed and target torque at the next moment.

[0045] During specific implementation, S5. Obtain the first feedback parameter according to the first disturbance parameter and the second disturbance parameter. Specifically, the first disturbance parameter and the second disturbance parameter can be combined as the first feedback parameter, or obtained through calculation based on the first disturbance parameter and the second disturbance parameter.

[0046] S6. Combine the first feedback parameter with the control parameter of the ultra-high speed motor-driven air compressor to control the ultra-high speed motor-driven air compressor, so as to pre-eliminate the disturbance at the next moment. That is, during implementation, by feeding back the feedback parameter to the control parameter in advance, in this way, the disturbance can be pre-eliminated. It is beneficial to improve the control accuracy, and at the same time, it can prevent the lag of control.

[0047] Please refer to Figure 2 , the steps for obtaining the first feedback parameter include the following

[0048] S51. Interpolate the disturbance parameters corresponding to the current speed to the target speed at the next moment and the current torque to the target torque at the next moment to obtain a set of speed, torque and corresponding disturbance parameters. Assume that two adjacent moments are t1 and t2 respectively, and the disturbance parameter corresponding to t1 is S1, and the disturbance parameter corresponding to t2 is S2. When t1 is the current moment, interpolate the disturbance parameter. For example, between t1 and t2, insert 5 values, t11, t12, t13, t14 and t15; through interpolation, obtain the corresponding disturbance parameters, S11, S12, S13, S14 and S15. In this way, multiple interpolations between adjacent moments can be obtained to increase the disturbance parameters between adjacent moments, thereby improving the control fineness.

[0049] S52. Use the disturbance parameter as the first feedback parameter.

[0050] In specific implementation, since the pre-stored data of the ultra-high-speed electric air compressor is obtained through tests on other air compressors of the same model, although it is relatively accurate. However, due to certain differences between different air compressors, there are still certain differences between the pre-stored data of the ultra-high-speed electric air compressor. On the other hand, with the continuous use of the ultra-high-speed electric air compressor, due to certain wear and other reasons of the ultra-high-speed electric air compressor, the pre-stored data of the ultra-high-speed electric air compressor cannot reflect the real disturbance data. In order to make the pre-stored data of the ultra-high-speed electric air compressor accurately adapt to the real state of different air compressors at different life stages. The present invention has made further improvements. In specific implementation, it also includes pre-stored data correction;

[0051] S7, obtain the actual disturbance data at the current moment. Specifically, the actual disturbance data is obtained by a sensor.

[0052] S8, cache the actual disturbance data at the current moment corresponding to the actual rotational speed and actual torque at the current moment. In specific implementation, the cached data is sorted in order from front to back according to the time of storage, so as to facilitate deleting the pre-stored data according to the time sequence when correcting the pre-stored data.

[0053] Specifically, the specific steps of correction are: S9, judge whether the number of actual disturbance data corresponding to the actual rotational speed and actual torque at the current moment is greater than N, if so, obtain the median of the disturbance data, and use it as the new disturbance parameter to modify the corresponding disturbance parameter in the pre-stored data of the ultra-high-speed electric air compressor, and eliminate the first M cached disturbance data; where N is an integer not less than 100, and M is a positive integer not greater than N / 2. By correcting the pre-stored data, the disturbance parameter can always adapt to the state of the ultra-high-speed electric air compressor to ensure the accuracy of control. In specific implementation, as a preferred implementation, the value of N is 200, and the value of M is 80.

[0054] In specific implementation, the time interval between the current moment and the next moment is not greater than 1S. In application, the smaller the time interval, the more accurate the control of the disturbance, but the calculation amount will also increase exponentially. And when the time interval is too small, the improvement of the control accuracy will become worse. Therefore, in this application, the preferred time interval is between 0.05 and 0.2 seconds, preferably 0.01 second.

[0055] Using the above scheme, by pre-storing the rotational speed, torque and the corresponding disturbance parameters, so as to estimate the disturbance parameter at the next moment during control, and thus pre-adjust the control parameter at the next moment, the disturbance at the next moment can be effectively reduced.

[0056] Embodiment 2

[0057] This embodiment is a further improvement made on the basis of embodiment 1. The similarities are not repeated here, and only the differences are described below.

[0058] Through the solution provided in Example 1, although the feedback parameters can be combined with the control parameters in advance to eliminate disturbances, there is no tracking feedback for the actual control results, which will affect the control effect to a certain extent. Figure 3 and Figure 4 In order to further adjust the control effect at the next moment according to the actual control effect, S6 is replaced by the following steps:

[0059] S061, obtaining the actual disturbance parameter at the current moment, and caching the actual disturbance parameter at the current moment. The main purpose of caching the actual disturbance parameter is to perform post-feedback control according to the actual control result.

[0060] The difference is that in this embodiment, the post-feedback control is not performed in real time, but only under certain conditions. Specifically, S062 determines whether the actual disturbance parameter at the current moment is greater than the set value; when implemented, there are multiple set values, which vary depending on the speed and torque. Specifically, under a certain speed and torque, the set value should not be greater than half of the maximum value allowed.

[0061] S063, if the proportion of disturbance parameters greater than the set value in S consecutive time intervals exceeds 50%, the second feedback parameter is obtained according to all actual disturbance parameters obtained in the S consecutive time intervals. Specifically, when the proportion of disturbance parameters greater than the set value in S consecutive time intervals exceeds 50%, it means that in S consecutive time intervals, more than half of the time, the disturbance parameter is greater than the set value. In this case, it means that the corresponding control accuracy cannot be achieved by relying only on the first feedback parameter and the control parameter. At this time, the second feedback parameter needs to be involved in the control.

[0062] S064, combining the second feedback parameter and the first feedback parameter with the control parameter of the ultra-high-speed electric air compressor to control the ultra-high-speed electric air compressor to eliminate the disturbance at the next moment; wherein S is a positive integer not less than 30.

[0063] The method for obtaining the second feedback parameter is as follows: S0631, calculating the average value of all actual disturbance parameters obtained in the continuous S time intervals; S0632, using the average value as the second feedback parameter. In specific implementation, when calculating the average value, the maximum value and the minimum value are first eliminated.

[0064] In specific implementation, the pre-stored data of the ultra-high-speed electric air compressor further includes rotational acceleration, intake air volume, and intake and exhaust pressure difference. It should be noted that the more types of pre-stored data, the more exponentially the amount of data to be stored increases. At the same time, the more types of data related to disturbances, the more accurate the control.

[0065] The structure, features, and effects of the present invention have been described in detail based on the embodiments shown in the drawings. The above is only the preferred embodiment of the present invention, but the present invention is not limited to the implementation scope shown in the drawings. Any changes made in accordance with the concept of the present invention, or equivalent embodiments modified into equivalent changes, still within the spirit covered by the description and the drawings, should be within the protection scope of the present invention.

Claims

1. A self-disturbance rejection control method for a fuel cell electric air compressor, where the electric air compressor is used in a fuel cell vehicle, Characterized in that: It includes the following steps, Pre-store the data of the ultra-high-speed electric air compressor, including the rotational speed, torque, and corresponding disturbance parameters; Obtain the actual rotational speed and actual torque of the ultra-high-speed electric air compressor in real time, and obtain the target rotational speed and target torque at the next moment according to the working conditions; Obtain the corresponding disturbance parameters according to the actual rotational speed and actual torque, denoted as the first disturbance parameter; Obtain the corresponding disturbance parameters according to the target rotational speed and target torque at the next moment, denoted as the second disturbance parameter; Obtain the first feedback parameter according to the first disturbance parameter and the second disturbance parameter; Merge the first feedback parameter with the control parameter of the ultra-high-speed electric air compressor and then control the ultra-high-speed electric air compressor to pre-eliminate the disturbance at the next moment.

2. The self-disturbance rejection control method for a fuel cell electric air compressor according to claim 1, Characterized in that: Obtaining the first feedback parameter includes the following steps, Interpolate the disturbance parameters corresponding to the current rotational speed to the target rotational speed at the next moment and the current torque to the target torque at the next moment to obtain a set of rotational speeds, torques, and corresponding disturbance parameters; Use the disturbance parameter as the first feedback parameter.

3. The self-disturbance rejection control method for a fuel cell electric air compressor according to claim 1, Characterized in that: It also includes pre-storing data correction; Obtain the actual disturbance data at the current moment; Cache the actual disturbance data at the current moment corresponding to the actual rotational speed and actual torque at the current moment; Judge whether the number of actual disturbance data corresponding to the actual rotational speed and actual torque at the current moment is greater than N. If so, obtain the median of the disturbance data and use it as the new disturbance parameter to modify the corresponding disturbance parameter in the pre-stored ultra-high-speed electric air compressor data, and eliminate the first M pieces of cached disturbance data; where N is an integer not less than 100, and M is a positive integer not greater than N / 2.

4. The self-disturbance rejection control method for a fuel cell electric air compressor according to claim 1, Characterized in that: The time interval between the current moment and the next moment is not greater than 1S.

5. The self-disturbance rejection control method for a fuel cell electric air compressor according to claim 1, Characterized in that: It also includes the following steps, Obtain the actual disturbance parameter at the current moment and cache the actual disturbance parameter at the current moment; Judge whether the actual disturbance parameter at the current moment is greater than the set value; If the proportion of the disturbance parameters greater than the set value within S consecutive time intervals exceeds 50%, then obtain the second feedback parameter according to all the actual disturbance parameters obtained within these S consecutive time intervals; And merge the second feedback parameter and the first feedback parameter with the control parameter of the ultra-high-speed electric air compressor and then control the ultra-high-speed electric air compressor to eliminate the disturbance at the next moment; where S is a positive integer not less than 30.

6. The self-disturbance rejection control method for a fuel cell electric air compressor according to claim 5, Characterized in that: The method for obtaining the second feedback parameter is: Calculate the average value of all the actual disturbance parameters obtained within the consecutive S time intervals; Use this average value as the second feedback parameter.

7. The active disturbance rejection control method for a fuel cell electric air compressor according to claim 1, characterized in that: The pre-stored data of the ultra-high speed electric air compressor further includes rotational acceleration, intake air volume, and intake and exhaust pressure difference.

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