Voltage attenuation statistical method and device of fuel cell vehicle

Abstract

The invention belongs to the technical field of fuel cells, and provides a voltage attenuation statistical method and device for a fuel cell vehicle, and the method comprises the steps: obtaining at least one steady-state current and a corresponding time point of the fuel cell vehicle in a preset time period; searching the relationship between the absolute value of the difference between the steady-state current and the standard current at each time point, and calculating the statistical parameter of the steady-state current corresponding to each time point based on the relationship; and based on the statistical parameter of the steady-state current corresponding to each time point, performing statistics on voltage attenuation statistical data of the fuel cell vehicle. According to the voltage attenuation statistical method of the fuel cell vehicle, the problem that current points are inconsistent every day due to power closed loop is eliminated, and the voltage change trend under a certain current is obtained.

Description

Technical Field

[0001] The present invention relates to the technical field of fuel cell system testing, and in particular to a voltage decay statistics method and device for a fuel cell vehicle. Background Art

[0002] Fuel cell system refers to a system used as a driving power source or auxiliary power for vehicles, yachts, aerospace and underwater power equipment, etc., which converts the chemical energy of reactants into electrical energy and thermal energy through electrochemical reactions. When the fuel cell vehicle is running, the power spectrum of different fuel cell vehicles is inconsistent every day due to factors such as different road conditions and driving habits of different drivers, making it difficult to conduct comparative analysis of voltage attenuation.

[0003] Traditional solutions currently have the following disadvantages: 1. They affect the operation of the vehicle, resulting in a certain loss of actual operating time and increased customer complaints; 2. There are errors in statistics, and because the vehicle operation mode is a power closed loop, from the beginning to the end of its life, under the same power request, the current of the fuel cell will change significantly, resulting in statistical omissions. Summary of the invention

[0004] In order to solve the above problems, the present invention is achieved through the following technologies:

[0005] In some embodiments, the present invention provides a voltage decay statistics method for a fuel cell vehicle, comprising:

[0006] Obtaining at least one steady-state current and a corresponding time point of the fuel cell vehicle within a preset time period;

[0007] Finding the relationship between the absolute value of the difference between the steady-state current and the standard current at each time point, and calculating the statistical parameter of the steady-state current corresponding to each time point based on the relationship;

[0008] Based on the statistical parameters of the steady-state current corresponding to each time point, the voltage decay statistical data of the fuel cell vehicle are counted.

[0009] In some embodiments, the step of respectively finding the relationship between the absolute value of the difference between the steady-state current and the standard current at each time point, and calculating the statistical parameter of the steady-state current corresponding to each time point based on the relationship, comprises:

[0010] At each time point, respectively searching for a first target current whose absolute value of the difference between the steady-state current and the standard current is less than a first preset value;

[0011] If the absolute value of the difference between the first target current and the standard current is less than or equal to a second preset value, the average values ​​of all currents and the corresponding voltages within the floating range of the first target current are calculated to obtain a first average current and a first average voltage at the time point;

[0012] Wherein, the first preset value is greater than the second preset value.

[0013] In some embodiments, the statistical parameters of the steady-state current corresponding to each time point are used to calculate the voltage decay statistics of the fuel cell vehicle, including:

[0014] The first average current and the first average voltage are interpolated to generate voltage decay statistical data of the fuel cell vehicle.

[0015] In some embodiments, the step of respectively finding the relationship between the absolute value of the difference between the steady-state current and the standard current at each time point, and calculating the statistical parameter of the steady-state current corresponding to each time point based on the relationship, comprises:

[0016] If the absolute value of the difference between the first target current and the standard current is greater than the second preset value, calculate a second target current in which the difference between the current corresponding to the time point and the first target current is greater than the second preset value and the first target current and the standard current are less than a third preset value;

[0017] All currents within the first target current floating range and all currents within the second target current floating range are averaged to obtain a second average current, a second average voltage, a third average current and a third average voltage.

[0018] In some embodiments, the statistical parameters of the steady-state current corresponding to each time point are used to calculate the voltage decay data of the fuel cell vehicle, including:

[0019] Judging whether the steady-state current conforms to a voltage decay trend according to a statistical parameter of the steady-state current;

[0020] The steady-state current that conforms to the voltage decay trend is interpolated to generate voltage decay statistical data of the fuel cell vehicle.

[0021] In some embodiments, judging whether the steady-state current conforms to the voltage decay trend according to the statistical parameter of the steady-state current includes:

[0022] determining whether if the second mean current is greater than the third mean current, then the second mean voltage is less than the third mean voltage;

[0023] determining whether if the second mean current is less than the third mean current, then the second mean voltage is greater than the third mean voltage;

[0024] If the above conditions are met, it is determined that the steady-state current complies with the voltage decay trend.

[0025] In some embodiments, interpolating the steady-state current that conforms to the current decay trend to generate voltage decay statistics of the fuel cell vehicle includes:

[0026] The voltage decay statistics of the fuel cell vehicle are obtained by a linear interpolation formula, which is as follows:

[0027] Voltage = b1-(b1-d1) / (a1-c1)*(a1-standard current);

[0028] Among them, b1 is the second mean voltage; d1 is the third mean voltage; a1 is the second mean current; c1 is the third mean current.

[0029] In some embodiments, the present invention further provides a voltage decay statistics device for a fuel cell vehicle, comprising:

[0030] An acquisition module, used to acquire at least one steady-state current and a corresponding time point of the fuel cell vehicle within a preset time period;

[0031] A calculation module, used to find the relationship between the absolute value of the difference between the steady-state current and the standard current at each time point, and calculate the statistical parameter of the steady-state current corresponding to each time point based on the relationship;

[0032] A statistical module is used to collect statistical data of voltage decay of the fuel cell vehicle based on the statistical parameters of the steady-state current corresponding to each time point.

[0033] In some embodiments, the computing module is used to:

[0034] At each time point, respectively searching for a first target current whose absolute value of the difference between the steady-state current and the standard current is less than a first preset value;

[0035] If the absolute value of the difference between the first target current and the standard current is less than or equal to a second preset value, the average values ​​of all currents and the corresponding voltages within the floating range of the first target current are calculated to obtain a first average current and a first average voltage at the time point;

[0036] Wherein, the first preset value is greater than the second preset value.

[0037] In some embodiments, the statistics module is further used to:

[0038] The first average current and the first average voltage are interpolated to generate voltage decay statistical data of the fuel cell vehicle.

[0039] The voltage decay statistics method and device for a fuel cell vehicle provided by the present invention have at least the following beneficial effects:

[0040] The voltage decay statistics method for a fuel cell vehicle of the present invention does not require additional testing through interpolation calculation, thereby eliminating the problem of inconsistent current points every day caused by a power closed loop, and obtaining a voltage change trend under a certain current. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] The following will explain the preferred implementation mode in a clear and understandable manner in conjunction with the accompanying drawings, and further illustrate the above-mentioned characteristics, technical features, advantages and implementation methods of a voltage decay statistics method and device for a fuel cell vehicle.

[0042] Figure 1 It is a schematic diagram of an embodiment of a voltage decay statistical method for a fuel cell vehicle in the present invention;

[0043] Figure 2 It is a schematic diagram of an embodiment of a voltage decay statistics device for a fuel cell vehicle in the present invention. DETAILED DESCRIPTION

[0044] In the following description, specific details such as specific system structures, technologies, etc. are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present application. However, it should be clear to those skilled in the art that the present application may also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present application.

[0045] It should be understood that when used in this specification and the appended claims, the term "comprising" indicates the presence of the described features, integers, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or collections.

[0046] In order to simplify the drawings, only the parts related to the present invention are schematically shown in each figure, and they do not represent the actual structure of the product. In addition, in order to simplify the drawings and facilitate understanding, in some figures, only one of the parts with the same structure or function is schematically drawn or marked. In this article, "one" not only means "only one", but also means "more than one".

[0047] It should be further understood that the term “and / or” used in the specification and appended claims refers to any combination and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0048] In addition, in the description of the present application, the terms "first", "second", etc. are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0049] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the specific implementation methods of the present invention will be described below with reference to the accompanying drawings. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings and other implementation methods can be obtained based on these drawings without creative work.

[0050] In one embodiment, Figure 1 As shown, the present invention provides a voltage decay statistics method for a fuel cell vehicle, comprising:

[0051] S101 obtains at least one steady-state current and a corresponding time point of a fuel cell vehicle within a preset time period.

[0052] Specifically, select a current density that you want to analyze, convert the current density into current according to the active area of ​​the fuel cell stack, and screen all stable points by using a current change within plus or minus 5A and a stable time of more than 120s. The current corresponding to the stable point is called the steady-state current, and its time information is retrieved.

[0053] Among them, electric density is the abbreviation of current density, that is, the density of charge flow, that is, the amount of current per unit cross-sectional area. You can select more than one electric density to analyze.

[0054] S102 respectively searches for the relationship between the absolute value of the difference between the steady-state current and the standard current at each time point, and calculates the statistical parameter of the steady-state current corresponding to each time point based on the relationship.

[0055] Among them, statistical parameters include mean.

[0056] S103 collects statistical data of voltage decay of the fuel cell vehicle based on the statistical parameters of the steady-state current corresponding to each time point.

[0057] The voltage decay statistics method for a fuel cell vehicle of the present invention does not require additional testing through interpolation calculation, thereby eliminating the problem of inconsistent current points every day caused by a power closed loop, and obtaining a voltage change trend under a certain current.

[0058] In one embodiment, the step of respectively finding the relationship between the absolute value of the difference between the steady-state current and the standard current at each time point, and calculating the statistical parameter of the steady-state current corresponding to each time point based on the relationship, includes:

[0059] At each time point, respectively searching for a first target current whose absolute value of the difference between the steady-state current and the standard current is less than a first preset value;

[0060] If the absolute value of the difference between the first target current and the standard current is less than or equal to a second preset value, the average values ​​of all currents and the corresponding voltages within the floating range of the first target current are calculated to obtain a first average current and a first average voltage at the time point;

[0061] The first preset value is greater than the second preset value. The first preset value is an empirical value, and the second preset value is defined by the accuracy of the reference current sensor, which is generally within 5A.

[0062] The statistical parameters of the steady-state current corresponding to each time point are used to calculate the voltage decay statistics of the fuel cell vehicle, including:

[0063] The first average current and the first average voltage are interpolated to generate voltage decay statistical data of the fuel cell vehicle.

[0064] Exemplarily, the standard current is the reference current to be calculated. Take 301A as an example. Assuming the standard current is 301A, group by date (day). On each date, find the value 1 that satisfies the absolute value of (current-301) less than 30 and closest to 301A. Value 1 is the first target current. If no value is found, do not fill it in.

[0065] If the absolute value of (value 1-301) is less than or equal to 2 (the second preset value), find all values ​​within positive and negative 2A (floating range) of value 1, calculate the average value a (the first mean current) and the corresponding average value b (the first mean voltage), and obtain the current and voltage on the current date.

[0066] The fuel cell load increase and load decrease are considered, and the influence of load increase and load decrease on the parameters is ignored. In this embodiment, the system performance is mainly considered, and the performance of load increase is lower than that of load decrease, and the voltages corresponding to load increase and load decrease are different.

[0067] Among them, the preset value is the preset value selected after several groups of comparisons based on the real vehicle data. For example, the second preset value 2, in principle, its range is definitely smaller and closer to the original value, but at the same time, the number that can be obtained is also less. However, the third preset value 60, the lower the number given, the fewer points can be found, and the higher the accuracy, the more low points. Because the relationship between the second preset value and the original value is not equivalent, for example, you need to take a voltage corresponding to the current of 301A, but now there is a value very close to it to be considered as 301A. But the second method is that if it is not so close, you have to calculate it. For example, for 301A, there is a 330A and a 270A. At this time, you need to calculate the difference to figure out how much 300A is. At this time, the range can be appropriately relaxed.

[0068] In one embodiment, it further includes:

[0069] The step of respectively finding the relationship between the absolute value of the difference between the steady-state current and the standard current at each time point, and calculating the statistical parameter of the steady-state current corresponding to each time point based on the relationship, includes:

[0070] If the absolute value of the difference between the first target current and the standard current is greater than the second preset value, calculate a second target current in which the difference between the current corresponding to the time point and the first target current is greater than the second preset value and the first target current and the standard current are less than a third preset value;

[0071] All currents within the first target current floating range and all currents within the second target current floating range are averaged to obtain a second average current, a second average voltage, a third average current and a third average voltage.

[0072] Based on the above embodiments, in this embodiment, if the absolute value of (value 1-301) is greater than 2 (the second preset value), find the value 2 (the second target current) that is closest to 301A and whose (current-value 1) is greater than 2 and (the value-301) is less than 60 (the third preset value).

[0073] For all currents within positive and negative 2A of value 1 and value 2, the average values ​​a1 (second average current) and c1 (third average current) and the average values ​​b1 (second average voltage) and d1 (third average voltage) are calculated respectively.

[0074] In one embodiment, the statistical parameters of the steady-state current corresponding to each time point are used to calculate the voltage decay data of the fuel cell vehicle, including:

[0075] Judging whether the steady-state current conforms to a voltage decay trend according to a statistical parameter of the steady-state current;

[0076] Interpolate the steady-state current that conforms to the described voltage decay trend to generate the voltage decay statistical data of the fuel cell vehicle.

[0077] Among them, judging whether the steady-state current conforms to the voltage decay trend according to the statistical parameters of the steady-state current includes:

[0078] Judge whether it satisfies that if the second average current is greater than the third average current, then the second average voltage is less than the third average voltage;

[0079] Judge whether it satisfies that if the second average current is less than the third average current, then the second average voltage is greater than the third average voltage;

[0080] If the above conditions are satisfied, it is determined that the steady-state current conforms to the voltage decay trend.

[0081] Specifically, judge whether it satisfies that if a1 > c1 then b1 < d1; if a1 < c1 then b1 > d1, and judge the trend; that is, judge whether the voltage and current are inversely proportional. If not satisfied, there is no value for this date, indicating inaccuracy (data screening for the entire life cycle).

[0082] In one embodiment, the interpolating the steady-state current that conforms to the current decay trend to generate the voltage decay statistical data of the fuel cell vehicle includes:

[0083] Obtain the voltage decay statistical data of the fuel cell vehicle through the linear interpolation formula, and the formula is as follows:

[0084] Voltage = b1 - (b1 - d1) / (a1 - c1) * (a1 - standard current);

[0085] Among them, b1 is the second average voltage; d1 is the third average voltage; a1 is the second average current; c1 is the third average current.

[0086] Exemplarily, taking 301A as an example, 8. Use linear interpolation to find the voltage corresponding to 301A, and the formula is:

[0087] Voltage = b1 - (b1 - d1) / (a1 - c1) * (a1 - 301);

[0088] Finally, a summary table including date, current, and voltage is obtained.

[0089] In one embodiment, as Figure 2 shown, the present invention also provides a voltage decay statistical device for a fuel cell vehicle, including:

[0090] An acquisition module 101 is used to acquire at least one steady-state current and a corresponding time point of a fuel cell vehicle within a preset time period;

[0091] A calculation module 102, used to calculate the statistical parameters of the steady-state current corresponding to each time point;

[0092] A judgment module 103, configured to judge whether the steady-state current conforms to a current decay trend according to a statistical parameter of the steady-state current;

[0093] The interpolation module 104 is used to interpolate the steady-state current that meets the current decay trend to generate voltage decay statistical data of the fuel cell vehicle.

[0094] In some embodiments, the computing module is further configured to:

[0095] At each time point, respectively searching for a first target current whose absolute value of the difference between the steady-state current and the standard current is less than a first preset value;

[0096] If the absolute value of the difference between the first target current and the standard current is less than or equal to a second preset value, the average values ​​of all currents and the corresponding voltages within the floating range of the first target current are calculated to obtain a first mean current and a first mean voltage at the time point; wherein the first preset value is greater than the second preset value.

[0097] In some embodiments, the computing module is further configured to:

[0098] If the absolute value of the difference between the first target current and the standard current is greater than the second preset value, calculate a second target current in which the difference between the current corresponding to the time point and the first target current is greater than the second preset value and the first target current and the standard current are less than a third preset value;

[0099] All currents within the first target current floating range and all currents within the second target current floating range are averaged to obtain a second average current and a second average voltage.

[0100] In some embodiments, the statistics module is further used to:

[0101] The first average current, the first average voltage and the second average current are interpolated to generate voltage decay statistical data of the fuel cell vehicle.

[0102] Based on the above embodiments, the device part and the method part in this embodiment correspond to each other, and they will not be described one by one.

[0103] In the embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0104] It should be noted that the above embodiments can be freely combined as needed. The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered as the protection scope of the present invention.

Claims

1. A voltage decay statistical method for a fuel cell vehicle, characterized in that: include: Obtaining at least one steady-state current and a corresponding time point of the fuel cell vehicle within a preset time period; Finding the relationship between the absolute value of the difference between the steady-state current and the standard current at each time point, and calculating the statistical parameter of the steady-state current corresponding to each time point based on the relationship; Based on the statistical parameters of the steady-state current corresponding to each time point, the voltage decay statistical data of the fuel cell vehicle are counted.

2. The voltage decay statistical method for a fuel cell vehicle according to claim 1, characterized in that: The step of respectively finding the relationship between the absolute value of the difference between the steady-state current and the standard current at each time point, and calculating the statistical parameter of the steady-state current corresponding to each time point based on the relationship, includes: At each time point, respectively searching for a first target current whose absolute value of the difference between the steady-state current and the standard current is less than a first preset value; If the absolute value of the difference between the first target current and the standard current is less than or equal to a second preset value, the average values ​​of all currents and the corresponding voltages within the floating range of the first target current are calculated to obtain a first average current and a first average voltage at the time point; Wherein, the first preset value is greater than the second preset value.

3. The voltage decay statistical method for a fuel cell vehicle according to claim 2, characterized in that: The statistical parameters of the steady-state current corresponding to each time point are used to calculate the voltage decay statistics of the fuel cell vehicle, including: The first average current and the first average voltage are interpolated to generate voltage decay statistical data of the fuel cell vehicle.

4. The voltage decay statistical method for a fuel cell vehicle according to claim 1, characterized in that: The step of respectively finding the relationship between the absolute value of the difference between the steady-state current and the standard current at each time point, and calculating the statistical parameter of the steady-state current corresponding to each time point based on the relationship, includes: If the absolute value of the difference between the first target current and the standard current is greater than the second preset value, calculate a second target current in which the difference between the current corresponding to the time point and the first target current is greater than the second preset value and the first target current and the standard current are less than a third preset value; All currents within the first target current floating range and all currents within the second target current floating range are averaged to obtain a second average current, a second average voltage, a third average current and a third average voltage.

5. The voltage decay statistical method for a fuel cell vehicle according to claim 4, characterized in that: The statistical parameters of the steady-state current corresponding to each time point are used to calculate the voltage decay data of the fuel cell vehicle, including: Judging whether the steady-state current conforms to a voltage decay trend according to a statistical parameter of the steady-state current; The steady-state current that conforms to the voltage decay trend is interpolated to generate voltage decay statistical data of the fuel cell vehicle.

6. The voltage decay statistical method for a fuel cell vehicle according to claim 5, characterized in that: The step of judging whether the steady-state current conforms to the voltage attenuation trend according to the statistical parameter of the steady-state current includes: determining whether if the second mean current is greater than the third mean current, then the second mean voltage is less than the third mean voltage; determining whether if the second mean current is less than the third mean current, then the second mean voltage is greater than the third mean voltage; If the above conditions are met, it is determined that the steady-state current complies with the voltage decay trend.

7. The voltage decay statistical method for a fuel cell vehicle according to claim 6, characterized in that: The interpolating the steady-state current that conforms to the current decay trend to generate voltage decay statistics of the fuel cell vehicle includes: The voltage decay statistics of the fuel cell vehicle are obtained by a linear interpolation formula, which is as follows: Voltage = b1-(b1-d1) / (a1-c1)*(a1-standard current); Among them, b1 is the second mean voltage; d1 is the third mean voltage; a1 is the second mean current; c1 is the third mean current.

8. A voltage decay statistics device for a fuel cell vehicle, characterized in that: include: An acquisition module, used to acquire at least one steady-state current and a corresponding time point of the fuel cell vehicle within a preset time period; A calculation module, used to find the relationship between the absolute value of the difference between the steady-state current and the standard current at each time point, and calculate the statistical parameter of the steady-state current corresponding to each time point based on the relationship; A statistical module is used to collect statistical data of voltage decay of the fuel cell vehicle based on the statistical parameters of the steady-state current corresponding to each time point.

9. The voltage decay statistics device for a fuel cell vehicle according to claim 8, characterized in that: The computing module is used for: At each time point, respectively searching for a first target current whose absolute value of the difference between the steady-state current and the standard current is less than a first preset value; If the absolute value of the difference between the first target current and the standard current is less than or equal to a second preset value, the average values ​​of all currents and the corresponding voltages within the floating range of the first target current are calculated to obtain a first average current and a first average voltage at the time point; Wherein, the first preset value is greater than the second preset value.

10. The voltage decay statistics device for a fuel cell vehicle according to claim 9, characterized in that: The statistical module is also used for: The first average current and the first average voltage are interpolated to generate voltage decay statistical data of the fuel cell vehicle.

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