Fuel cell single chip consistency evaluation device and method

Abstract

The present invention provides a fuel cell single-chip consistency evaluation device and method. The device includes a fuel cell system, a bidirectional DC / DC converter, a vehicle power battery, a shutdown backup battery and a controller. The controller is used to supply power to the fuel cell system through the shutdown backup battery when the fuel cell system is in a shutdown state, and to control the bidirectional DC / DC converter to apply a preset AC disturbance signal to the fuel cell system to determine the AC impedance value of each single chip in the fuel cell system, and to determine the result of the fuel cell single-chip consistency evaluation based on each AC impedance value, thereby realizing accurate fuel cell single-chip consistency evaluation after the fuel cell system is shut down, and thereby more reliably monitoring the fuel cell system.

Description

Technical Field

[0001] The present invention relates to the technical field of fuel cell systems, and in particular to a fuel cell monolithic consistency evaluation device and method. Background Art

[0002] The performance of a fuel cell chip determines the output performance of the entire stack, and the difference in performance between each chip leads to the problem of chip consistency in the stack.

[0003] In existing technology, on-vehicle fuel cell systems typically use a voltage inspection device to measure the voltage of each cell during operation and calculate its standard deviation, variance, and other parameters to evaluate cell consistency. This method cannot be used when the fuel cell system is shut down for an extended period of time due to the lack of voltage.

[0004] Therefore, how to carry out fuel cell single chip consistency evaluation after the fuel cell system is shut down is a technical problem that needs to be solved. Summary of the Invention

[0005] The present invention discloses a fuel cell single chip consistency evaluation device to solve the technical problem in the prior art that the fuel cell single chip consistency evaluation cannot be performed after the fuel cell system is shut down. The device includes a fuel cell system, a bidirectional DC / DC converter, a vehicle power battery, a shutdown backup battery and a controller, wherein:

[0006] The positive electrode and negative electrode of the fuel cell system are connected to the first end and the second end of the bidirectional DC / DC converter respectively, the third end of the bidirectional DC / DC converter is connected to the positive electrode of the vehicle power battery and the positive electrode of the shutdown backup battery, and the fourth end of the bidirectional DC / DC converter is connected to the negative electrode of the vehicle power battery and the negative electrode of the shutdown backup battery;

[0007] The controller is used to supply power to the fuel cell system through the shutdown backup battery when the fuel cell system is in a shutdown state, and to control the bidirectional DC / DC converter to apply a preset AC disturbance signal to the fuel cell system to determine the AC impedance value of each single chip in the fuel cell system, and to determine the result of the consistency evaluation of the fuel cell single chip based on each of the AC impedance values.

[0008] In some embodiments of the present application, the device further includes a voltage patrol device and a current sensor, and the controller is specifically configured to:

[0009] After controlling the bidirectional DC / DC converter to apply a preset AC disturbance signal to the fuel cell system, obtaining a first voltage signal of each single chip in the fuel cell system based on the voltage inspection device;

[0010] Acquiring a current signal of each chip in the fuel cell system based on the current sensor;

[0011] The AC impedance values ​​are determined after performing fast Fourier transform on the first voltage signal and the current signal.

[0012] In some embodiments of the present application, the current sensor is disposed in the bidirectional DC / DC converter.

[0013] In some embodiments of the present application, the controller is further configured to:

[0014] When the fuel cell system is in operation, obtaining a second voltage signal of each single chip in the fuel cell system based on the voltage inspection device;

[0015] The result of the fuel cell single chip consistency evaluation is determined based on the standard deviation or variance of each of the second voltage signals.

[0016] In some embodiments of the present application, the controller is specifically configured to:

[0017] Determining a local anomaly factor for each of the AC impedance values ​​based on a local anomaly factor algorithm;

[0018] The result of the fuel cell single chip consistency evaluation is determined based on the local abnormality factor of each of the AC impedance values.

[0019] In some embodiments of the present application, the controller is specifically configured to:

[0020] The result of the fuel cell single chip consistency evaluation is determined based on the standard deviation or variance of each of the AC impedance values.

[0021] In some embodiments of the present application, the controller is further configured to:

[0022] After determining the result of the fuel cell single chip consistency evaluation in the shutdown state, an interrupt signal is sent to the shutdown backup battery to cause the shutdown backup battery to stop supplying power to the fuel cell system.

[0023] In some embodiments of the present application, the controller determines that the fuel cell system enters a shutdown state based on a shutdown signal obtained from a vehicle controller.

[0024] In some embodiments of the present application, the controller is an all-in-one controller.

[0025] Accordingly, the present invention also proposes a fuel cell monolithic consistency evaluation method, which is applied to the above-mentioned device, and the method comprises:

[0026] When the fuel cell system is in a shutdown state, power is supplied to the fuel cell system through the shutdown backup battery;

[0027] Controlling the bidirectional DC / DC converter to apply a preset AC disturbance signal to the fuel cell system to determine the AC impedance value of each single chip in the fuel cell system;

[0028] The result of the fuel cell single chip consistency evaluation is determined based on each of the AC impedance values.

[0029] By applying the above technical solution, a fuel cell single-chip consistency evaluation device includes a fuel cell system, a bidirectional DC / DC converter, a vehicle power battery, a shutdown backup battery and a controller, wherein the positive and negative poles of the fuel cell system are respectively connected to the first and second ends of the bidirectional DC / DC converter, the third end of the bidirectional DC / DC converter is connected to the positive pole of the vehicle power battery and the positive pole of the shutdown backup battery, and the fourth end of the bidirectional DC / DC converter is connected to the negative pole of the vehicle power battery and the negative pole of the shutdown backup battery; the controller is used to supply power to the fuel cell system through the shutdown backup battery when the fuel cell system is in a shutdown state, and control the bidirectional DC / DC converter to apply a preset AC disturbance signal to the fuel cell system to determine the AC impedance value of each single chip in the fuel cell system, and determine the result of the fuel cell single chip consistency evaluation based on each AC impedance value, thereby realizing accurate fuel cell single chip consistency evaluation after the fuel cell system is shut down, and thus more reliably monitoring the fuel cell system.

[0030] This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the disclosure, nor is it intended to limit the scope of the disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The above and other objects, features and advantages of the present disclosure will become more apparent through a more detailed description of exemplary embodiments of the present disclosure with reference to the accompanying drawings, wherein like reference numerals generally represent like components throughout the exemplary embodiments of the present disclosure.

[0032] Figure 1 A schematic structural diagram of a fuel cell single chip consistency evaluation device according to an embodiment of the present invention is shown;

[0033] Figure 2 A schematic flow chart of a fuel cell monolithic consistency evaluation method according to an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0034] Embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided to make the present disclosure more thorough and complete, and to fully convey the scope of the present disclosure to those skilled in the art.

[0035] As used herein, the term "including" and its variations represent open inclusion, i.e., "including but not limited to." Unless otherwise stated, the term "or" means "and / or." The term "based on" means "based at least in part on." The terms "an example embodiment" and "an embodiment" mean "at least one example embodiment." The term "another embodiment" means "at least one additional embodiment." The terms "first," "second," etc. may refer to different or the same objects. Other explicit and implicit definitions may also be included below.

[0036] The present application provides a fuel cell single chip consistency evaluation device, such as Figure 1 As shown, the device includes a fuel cell system FC, a bidirectional DC / DC converter, a vehicle power battery BAT1, a shutdown backup battery BAT2 and a controller, wherein:

[0037] The positive electrode and negative electrode of the fuel cell system FC are connected to the first terminal and the second terminal of the bidirectional DC / DC converter respectively. The third terminal of the bidirectional DC / DC converter is connected to the positive electrode of the vehicle power battery BAT1 and the positive electrode of the shutdown backup battery BAT2. The fourth terminal of the bidirectional DC / DC converter is connected to the negative electrode of the vehicle power battery BAT1 and the negative electrode of the shutdown backup battery BAT2.

[0038] The controller is used to supply power to the fuel cell system FC via the shutdown backup battery BAT2 when the fuel cell system FC is in a shutdown state, and to control the bidirectional DC / DC converter to apply a preset AC disturbance signal to the fuel cell system FC, thereby determining the AC impedance value of each single chip in the fuel cell system FC, and to determine the result of the fuel cell single chip consistency evaluation based on each AC impedance value.

[0039] In this embodiment, the fuel cell system FC is an electrochemical reaction device. Hydrogen and oxygen react on both sides of the proton exchange membrane inside the stack and generate water on the air side, converting chemical energy into electrical energy. The fuel cell system FC is mainly composed of a fuel cell stack, an air subsystem, a hydrogen subsystem and a cooling subsystem.

[0040] The fuel cell single-chip consistency evaluation device includes a vehicle power battery BAT1 and a shutdown backup battery BAT2, which can be a lithium battery or other battery type. The bidirectional DC / DC converter integrates functions such as bidirectional output, boost, buck, and AC disturbance. However, conventional DC / DC converters are unidirectional and not connected to the shutdown backup battery. Therefore, the AC disturbance signal, thus determining the AC impedance value of the single chip, can only be applied when the fuel cell system is in operation.

[0041] In this embodiment, after the fuel cell system FC is shut down, the vehicle power battery BAT1 is in an unawakened state. The controller wakes up the shutdown backup battery BAT2 to supply power to the fuel cell system FC, and controls the bidirectional DC / DC converter to apply a preset AC disturbance signal to the fuel cell system FC. Then, the AC impedance value of each single chip in the fuel cell system FC can be determined. Based on each AC impedance value, the result of the fuel cell single chip consistency evaluation can be determined. Through the result of the fuel cell single chip consistency evaluation, the performance difference of each single chip in the fuel cell system FC can be determined, and the single chip with abnormal performance can be detected.

[0042] It should be noted that the specific process of controlling the bidirectional DC / DC converter to apply a preset AC disturbance signal to the fuel cell system FC is a prior art and will not be described in detail here.

[0043] In order to reliably determine the AC impedance value of each single chip in the fuel cell system FC, in some embodiments of the present application, the device further includes a voltage inspection device and a current sensor, and the controller is specifically configured to:

[0044] After controlling the bidirectional DC / DC converter to apply a preset AC disturbance signal to the fuel cell system FC, a first voltage signal of each single chip in the fuel cell system FC is obtained based on the voltage inspection device;

[0045] Obtain the current signal of each single chip in the fuel cell system FC based on the current sensor;

[0046] The AC impedance values ​​are determined after performing fast Fourier transform on the first voltage signal and the current signal.

[0047] In this embodiment, the controller controls the bidirectional DC / DC converter to apply a preset AC disturbance signal to the fuel cell system FC. After the value measured by the current sensor stabilizes, the voltage inspection device is started. The first voltage signal of each single chip in the fuel cell system FC is obtained based on the voltage inspection device, and the current signal of each single chip in the fuel cell system FC is obtained based on the current sensor. Then, a fast Fourier transform is performed on the first voltage signal and the current signal, and each AC impedance value is determined based on the results of the fast Fourier transform.

[0048] It should be noted that the specific process of performing fast Fourier transform on the first voltage signal and the current signal is prior art and will not be described in detail here.

[0049] In order to reliably obtain the current signal of each single chip in the fuel cell system FC, in some embodiments of the present application, the current sensor is arranged in the bidirectional DC / DC converter.

[0050] Those skilled in the art may also place the current sensor at other locations that can accurately detect the current of each single chip, which does not affect the protection scope of this application.

[0051] In order to ensure the reliability of the system, in some embodiments of the present application, the controller is further configured to:

[0052] When the fuel cell system FC is in operation, a second voltage signal of each single chip in the fuel cell system FC is obtained based on the voltage inspection device;

[0053] The result of the fuel cell single chip consistency evaluation is determined based on the standard deviation or variance of each second voltage signal.

[0054] In this embodiment, when the fuel cell system FC is in operation, the second voltage signal of each single chip in the fuel cell system FC is first obtained based on the voltage inspection device, and then the standard deviation or variance of each second voltage signal is calculated to obtain the result of the consistency evaluation of the fuel cell single chip.

[0055] Optionally, when the fuel cell system FC is in operation, the bidirectional DC / DC converter is controlled to apply a preset AC disturbance signal to the fuel cell system FC to determine the AC impedance value of each single chip in the fuel cell system FC, and the result of the fuel cell single chip consistency evaluation is determined based on the AC impedance value of each single chip.

[0056] It can be understood that when the fuel cell system FC is in operation, the shutdown backup battery BAT2 does not supply power to the fuel cell system FC.

[0057] In order to accurately evaluate the consistency of a fuel cell monolithic chip, in some embodiments of the present application, the controller is specifically used to:

[0058] Determine the local anomaly factor of each AC impedance value based on the local anomaly factor algorithm;

[0059] The results of the fuel cell single chip consistency evaluation are determined based on the local abnormality factor of each AC impedance value.

[0060] In this embodiment, the local anomaly factor is specifically calculated as the ratio of the average density of the sample points surrounding a sample point to the density at the sample point itself. The greater this ratio is, the smaller the density at the point is compared to the density at the surrounding sample points, and the more likely this point is an anomaly. Therefore, the degree to which the anomaly factor of a single-chip AC impedance value is greater than 1 can be used to determine its consistency.

[0061] Optionally, in some embodiments of the present application, the controller is specifically configured to:

[0062] The results of the fuel cell single chip consistency evaluation are determined based on the standard deviation or variance of each AC impedance value.

[0063] In order to improve the reliability of the system, in some embodiments of the present application, the controller is further configured to:

[0064] After the result of the fuel cell single chip consistency evaluation is determined in the shutdown state, an interrupt signal is sent to the shutdown backup battery BAT2 to cause the shutdown backup battery BAT2 to stop supplying power to the fuel cell system FC.

[0065] In order to ensure the reliability of the system, in some embodiments of the present application, such as Figure 1 As shown, the controller determines that the fuel cell system FC enters the shutdown state according to the shutdown signal obtained from the vehicle controller VCU.

[0066] In order to improve the reliability of the system, in some embodiments of the present application, the controller is an all-in-one controller.

[0067] In this embodiment, the all-in-one controller may include but is not limited to a multi-core control module, a low-voltage processing circuit module, a step-down DC / DC power drive module, a hydrogen pump drive module, a water pump drive module, an air compressor drive module, a boost DC / DC and a high-voltage power distribution module and a functional safety module.

[0068] By applying the above technical solution, a fuel cell single-chip consistency evaluation device includes a fuel cell system, a bidirectional DC / DC converter, a vehicle power battery, a shutdown backup battery and a controller, wherein the positive and negative poles of the fuel cell system are respectively connected to the first and second ends of the bidirectional DC / DC converter, the third end of the bidirectional DC / DC converter is connected to the positive pole of the vehicle power battery and the positive pole of the shutdown backup battery, and the fourth end of the bidirectional DC / DC converter is connected to the negative pole of the vehicle power battery and the negative pole of the shutdown backup battery; the controller is used to supply power to the fuel cell system through the shutdown backup battery when the fuel cell system is in a shutdown state, and control the bidirectional DC / DC converter to apply a preset AC disturbance signal to the fuel cell system to determine the AC impedance value of each single chip in the fuel cell system, and determine the result of the fuel cell single chip consistency evaluation based on each AC impedance value, thereby realizing accurate fuel cell single chip consistency evaluation after the fuel cell system is shut down, and thus more reliably monitoring the fuel cell system.

[0069] Corresponding to a fuel cell monolithic consistency evaluation device in the embodiment of the present application, the embodiment of the present application also proposes a fuel cell monolithic consistency evaluation method, which is applied to the device as described above, such as Figure 2 As shown, the method includes the following steps:

[0070] Step S101, when the fuel cell system is in a shutdown state, supplying power to the fuel cell system through the shutdown backup battery;

[0071] Step S102 , controlling the bidirectional DC / DC converter to apply a preset AC disturbance signal to the fuel cell system and then determining an AC impedance value of each chip in the fuel cell system;

[0072] Step S103 : determining a fuel cell single chip consistency evaluation result based on each of the AC impedance values.

[0073] While various embodiments of the present disclosure have been described above, the above descriptions are illustrative, non-exhaustive, and not intended to be limiting of the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is selected to best explain the principles of the embodiments, their practical applications, or improvements to existing technologies, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A fuel cell single chip consistency evaluation device, characterized in that: The device includes a fuel cell system, a bidirectional DC / DC converter, a vehicle power battery, a shutdown backup battery and a controller, wherein: The positive electrode and negative electrode of the fuel cell system are connected to the first end and the second end of the bidirectional DC / DC converter respectively, the third end of the bidirectional DC / DC converter is connected to the positive electrode of the vehicle power battery and the positive electrode of the shutdown backup battery, and the fourth end of the bidirectional DC / DC converter is connected to the negative electrode of the vehicle power battery and the negative electrode of the shutdown backup battery; The controller is configured to, when the fuel cell system is in a shutdown state, supply power to the fuel cell system via the shutdown backup battery, control the bidirectional DC / DC converter to apply a preset AC disturbance signal to the fuel cell system, determine an AC impedance value of each single chip in the fuel cell system, and determine a result of a fuel cell single chip consistency evaluation based on each AC impedance value; The device further includes a voltage patrol device and a current sensor, and the controller is specifically configured to: after controlling the bidirectional DC / DC converter to apply a preset AC disturbance signal to the fuel cell system, obtain a first voltage signal of each single chip in the fuel cell system based on the voltage patrol device; obtain a current signal of each single chip in the fuel cell system based on the current sensor; and determine each AC impedance value after performing a fast Fourier transform on the first voltage signal and the current signal; The controller is specifically used to: determine the local abnormality factor of each of the AC impedance values ​​based on a local abnormality factor algorithm; determine the result of the fuel cell single chip consistency evaluation based on the local abnormality factor of each of the AC impedance values; or determine the result of the fuel cell single chip consistency evaluation based on the standard deviation or variance of each of the AC impedance values.

2. The device according to claim 1, wherein The current sensor is arranged in the bidirectional DC / DC converter.

3. The device according to claim 1, wherein The controller is also used for: When the fuel cell system is in operation, obtaining a second voltage signal of each single chip in the fuel cell system based on the voltage inspection device; The result of the fuel cell single chip consistency evaluation is determined based on the standard deviation or variance of each of the second voltage signals.

4. The device according to claim 1, wherein The controller is also used for: After determining the result of the fuel cell single chip consistency evaluation in the shutdown state, an interrupt signal is sent to the shutdown backup battery to cause the shutdown backup battery to stop supplying power to the fuel cell system.

5. The device according to claim 1, wherein The controller determines that the fuel cell system enters a shutdown state according to a shutdown signal obtained from a vehicle controller.

6. The device according to any one of claims 1 to 5, characterized in that The controller is an all-in-one controller.

7. A fuel cell monolithic consistency evaluation method, characterized in that: Applied to the apparatus according to any one of claims 1 to 6, the method comprises: When the fuel cell system is in a shutdown state, power is supplied to the fuel cell system through the shutdown backup battery; Controlling the bidirectional DC / DC converter to apply a preset AC disturbance signal to the fuel cell system to determine the AC impedance value of each single chip in the fuel cell system; The result of the fuel cell single chip consistency evaluation is determined based on each of the AC impedance values.

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