An active impedance measurement system for a fuel cell

Abstract

The application relates to the field of fuel cells and discloses an active impedance measurement system of a fuel cell, which comprises a DC / DC module, a control device, a first power battery and a second power battery. The fuel cell is connected with the first power battery and the second power battery through the DC / DC module. The fuel cell is connected with a voltage inspection device. The DC / DC module is connected with the control device. The control device is connected with the second power battery. The fuel cell comprises a start measurement mode and a stop measurement mode. In the start measurement mode, the first power battery and the fuel cell are synchronously awakened, and the first power battery supplies power to the DC / DC module. In the stop measurement mode, the first power battery and the fuel cell are synchronously stopped, and the control device awakens the second power battery to supply power to the DC / DC module. The active impedance measurement system of the fuel cell can measure the impedance in the running state of the fuel cell and in the shutdown state.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of fuel cell, in particular to an active impedance measurement system of fuel cell. BACKGROUND

[0002] The impedance state of fuel cell is crucial to the operation state of fuel cell. The impedance measurement system is specially used for measuring the impedance state of fuel cell, but the existing impedance measurement system can only measure the impedance in the process of fuel cell operation, and cannot measure the impedance in the shutdown state of fuel cell. SUMMARY

[0003] The present application mainly solves the technical problem that the existing impedance measurement system can only measure the impedance in the process of fuel cell operation, and cannot measure the impedance in the shutdown state of fuel cell, and provides an active impedance measurement system of fuel cell which can measure the impedance in the process of fuel cell operation and in the shutdown state.

[0004] In order to solve the above technical problems and achieve the above application purposes, the present application provides an active impedance measurement system of fuel cell, characterized in that it comprises a DC / DC module, a control device, a first power battery and a second power battery, the fuel cell is connected with the first power battery and the second power battery through the DC / DC module, the fuel cell is connected with a voltage inspection device, the DC / DC module is connected with the control device, and the control device is connected with the second power battery; the fuel cell comprises a start measurement mode and a shutdown measurement mode, in the start measurement mode, the first power battery and the fuel cell are awakened synchronously, and the first power battery supplies power to the DC / DC module; in the shutdown measurement mode, the first power battery and the fuel cell are shut down synchronously, and the control device wakes up the second power battery to supply power to the DC / DC module.

[0005] In an implementable manner, the second power battery is connected with a vehicle control unit.

[0006] In an implementable manner, the voltage inspection device is connected with the control device.

[0007] In an implementable manner, the fuel cell is connected with an air compressor, and the air compressor is connected with the control device.

[0008] The present application also provides a control method of an active impedance measurement system of fuel cell, characterized in that it comprises the following steps:

[0009] The control device monitors whether the fuel cell is in a shutdown state.

[0010] If the fuel cell is in the start-up state, the fuel cell enters the start-up measurement mode, the first power battery and the fuel cell are synchronously awakened, and the first power battery supplies power to the DC / DC module;

[0011] If the fuel cell is in the shutdown state, the first power battery and the fuel cell are synchronously stopped, and the control device wakes up the second power battery to supply power to the DC / DC module;

[0012] The control device controls the DC / DC module to apply an alternating disturbance signal of a certain frequency to the fuel cell;

[0013] The electrical inspection device obtains a single voltage signal and feeds it back to the control device;

[0014] The control device obtains the voltage signal and the current signal, and obtains the impedance value of each single piece through FFT transformation.

[0015] Compared with the prior art, the active impedance measurement system of the fuel cell has the following beneficial effects:

[0016] In the normal working condition of the fuel cell, the fuel cell is in the start-up measurement mode, the first power battery and the fuel cell are synchronously awakened, the first power battery supplies power to the DC / DC module, and the DC / DC module applies an alternating disturbance signal of a certain frequency to the fuel cell. In the shutdown measurement mode of the fuel cell, the first power battery and the fuel cell are synchronously stopped, the control device controls the second power battery to supply power to the DC / DC module, and the DC / DC module applies an alternating disturbance signal of a certain frequency to the fuel cell. The switching of the above two measurement modes can realize impedance measurement in the running state of the fuel cell and impedance measurement in the shutdown state.

[0017] Therefore, the application has the characteristics of reasonable structure and convenient use. BRIEF DESCRIPTION OF DRAWINGS

[0018] ATTACH Figure 1 is a circuit schematic diagram of the application.

[0019] The label in the figure is explained: 1, DC / DC module; 2, control device; 3, first power battery; 4, second power battery; 5, voltage inspection device; 6, fuel cell; 7, vehicle controller; 8, air compressor. DETAILED DESCRIPTION

[0020] In order to make the purposes, characteristics and advantages of the present application more obvious and easy to understand, 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. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0021] The impedance measurement system in the prior art can only measure impedance during the operation of the fuel cell, and cannot measure impedance in the shutdown state of the fuel cell.

[0022] Therefore, the present application provides an active impedance measurement system of a fuel cell 6, which comprises a DC / DC module 1, a control device 2, a first power battery 3 and a second power battery 4. The fuel cell 6 is connected to the first power battery 3 and the second power battery 4 through the DC / DC module 1. The fuel cell 6 is connected to a voltage inspection device 5. The DC / DC module 1 is connected to the control device 2. The control device 2 is connected to the second power battery 4. The fuel cell 6 comprises a start measurement mode and a shutdown measurement mode. In the start measurement mode, the first power battery 3 and the fuel cell 6 are synchronously awakened. The first power battery 3 supplies power to the DC / DC module 1. In the shutdown measurement mode, the first power battery 3 and the fuel cell 6 are synchronously shut down. The control device 2 awakens the second power battery 4 to supply power to the DC / DC module 1.

[0023] The present application also provides a control method of an active impedance measurement system of a fuel cell 6, which comprises the following steps:

[0024] The control device 2 monitors whether the fuel cell 6 is shut down;

[0025] If the fuel cell 6 is in a start state, the fuel cell 6 enters the start measurement mode. The first power battery 3 and the fuel cell 6 are synchronously awakened. The first power battery 3 supplies power to the DC / DC module 1.

[0026] If the fuel cell 6 is in a shutdown state, the first power battery 3 and the fuel cell 6 are synchronously shut down at this time. The control device 2 awakens the second power battery 4 to supply power to the DC / DC module 1.

[0027] The control device 2 controls the DC / DC module 1 to apply an alternating current disturbance signal of a certain frequency to the fuel cell 6.

[0028] The voltage inspection device obtains a single voltage signal and feeds it back to the control device 2.

[0029] The control device 2 obtains the voltage signal and the current signal, and obtains the impedance value of each single piece through FFT transformation.

[0030] Embodiment:

[0031] Figure 1 An embodiment of the active impedance measurement system of the fuel cell 6 is shown.

[0032] Reference is made to Figure 1 In the embodiment of the present application, an active impedance measurement system of the fuel cell 6 is shown, which is used to measure the impedance of the fuel cell 6 in the start-up state and the shutdown state of the fuel cell 6, comprising a first power battery 3 and a second power battery 4, the first power battery 3 supplies power to the DC / DC module 1 in the start-up state of the fuel cell 6, and the second power battery 4 supplies power to the DC / DC module 1 in the shutdown state of the fuel cell 6.

[0033] In the embodiment of the present application, the fuel cell 6 and the first power battery 3 constitute a whole vehicle power battery, wherein the fuel cell 6 and the first power battery 3 are linked together, that is, when the fuel cell 6 is in the start-up state, the first power battery 3 is also in the start-up state, and when the fuel cell 6 is in the shutdown state, the first power battery 3 is also in the shutdown state. Obviously, without the system, when the fuel cell 6 is in the shutdown state, the fuel cell 6 cannot measure the impedance value.

[0034] In the embodiment of the present application, it also comprises a DC / DC module 1 and a control device 2, the DC / DC module 1 integrates the functions of bidirectional output, voltage boost and voltage reduction, the fuel cell 6 is connected to the first power battery 3 and the second power battery 4 through the DC / DC module 1, the fuel cell 6 is connected to a voltage inspection device 5, the voltage inspection device 5 is used to measure the voltage of the fuel cell 6, the DC / DC module 1 is connected to the control device 2, the control device 2 is connected to the second power battery 4, and the fuel cell 6 comprises a start-up measurement mode and a shutdown measurement mode.

[0035] In the embodiment of the present application, the control device 2 is a multi-in-one controller used to control the DC / DC module 1, the voltage inspection device 5, the second power battery 4 and an air compressor 8.

[0036] The fuel cell 6 comprises a start-up measurement mode and a shutdown measurement mode. When the fuel cell 6 is in normal operation, the fuel cell 6 is in the start-up measurement mode, the first power battery 3 and the fuel cell 6 are synchronously awakened, the first power battery 3 supplies power to the DC / DC module 1, and the DC / DC module 1 applies an alternating disturbance signal of a certain frequency to the fuel cell 6. When the fuel cell 6 is in the shutdown measurement mode, the first power battery 3 and the fuel cell 6 are synchronously shut down, the control device 2 controls the second power battery 4 to supply power to the DC / DC module 1, and the DC / DC module 1 applies an alternating disturbance signal of a certain frequency to the fuel cell 6. The second power battery 4 serves as a backup power supply to supply power when the fuel cell 6 is shut down. The above two measurement modes can realize impedance measurement in the running state of the fuel cell 6 and impedance measurement in the shutdown state.

[0037] In the embodiment of the application, the voltage inspection device 5 is connected to the control device 2, the control device 2 obtains the voltage signal and the current signal, and obtains the impedance value of each single piece through FFT transformation. The voltage signal is obtained by the voltage inspection device 5, and the current signal is obtained by the control device 2 measuring the current on the line.

[0038] In the embodiment of the application, the second power battery is connected to the vehicle controller 7.

[0039] In the embodiment of the application, the fuel cell 6 is connected to the air compressor 8, the air compressor 8 is connected to the control device 2, the control device 2 judges the state of the proton exchange membrane of the fuel cell 6 according to the obtained impedance value, when it is judged that the proton exchange membrane is dry, the air flow is reduced, the air inlet pressure is increased, and the like to make the proton exchange membrane wet. When the fuel cell 6 is cold started, the water storage amount of the proton exchange membrane of the fuel cell 6 is estimated according to the obtained impedance value, the current at the cold start point is limited, and damage of the proton exchange membrane caused by icing in the cold start process is avoided.

[0040] Embodiment 2:

[0041] In the embodiment of the application, a control method of an active impedance measurement system of a fuel cell 6 is shown, which comprises the following steps:

[0042] The control device 2 monitors whether the fuel cell 6 is shut down;

[0043] If the fuel cell 6 is in the start-up state, the fuel cell 6 enters the start-up measurement mode, the first power battery 3 and the fuel cell 6 are synchronously awakened, and the first power battery 3 supplies power to the DC / DC module 1;

[0044] If the fuel cell 6 is in a shutdown state, and the first power battery 3 and the fuel cell 6 are in a synchronous shutdown state, the control device 2 wakes up the second power battery 4 to supply power to the DC / DC module 1;

[0045] The control device 2 controls the DC / DC module 1 to apply an AC disturbance signal of a certain frequency to the fuel cell 6;

[0046] The electrical inspection device obtains a single piece of voltage signal and feeds back to the control device 2;

[0047] The control device 2 obtains the impedance value of each single piece through the obtained voltage signal and current signal, and through FFT transformation.

[0048] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. Moreover, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples. In addition, the person skilled in the art can combine and combine the different embodiments or examples described in the present specification and the features of the different embodiments or examples without contradiction.

[0049] In addition, the terms "first", "second" are only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first", "second" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "a plurality of" is two or more, unless otherwise specifically limited.

[0050] The above is only a specific embodiment of the present application, but the protection scope of the present application is not limited thereto, and any person skilled in the art can easily think of changes or replacements within the technical scope disclosed in the present application, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. An active impedance measurement system for a fuel cell, characterized by, The fuel cell (6) is connected with the voltage inspection device (5), the DC / DC module (1) is connected with the control device (2), the control device (2) is connected with the second power battery (4); the fuel cell (6) comprises a start-up measurement mode and a shutdown measurement mode, in the start-up measurement mode, the first power battery (3) and the fuel cell (6) are synchronously awakened, and the first power battery (3) supplies power to the DC / DC module (1); in the shutdown measurement mode, the first power battery (3) and the fuel cell (6) are synchronously shut down, and the control device (2) awakens the second power battery (4) to supply power to the DC / DC module (1); The voltage inspection device (5) is connected with the control device (2); The fuel cell (6) is connected with the air compressor (8), and the air compressor (8) is connected with the control device (2); The second power battery (4) is connected with the vehicle controller (7).

2. A control method of an active impedance measurement system of a fuel cell, characterized by, The method comprises the following steps: The control device (2) monitors whether the fuel cell (6) is shut down; If the fuel cell (6) is in a start-up state, the fuel cell (6) enters the start-up measurement mode, the first power battery (3) and the fuel cell (6) are synchronously awakened, and the first power battery (3) supplies power to the DC / DC module (1); If the fuel cell (6) is in a shutdown state, the first power battery (3) and the fuel cell (6) are synchronously shut down, and the control device (2) awakens the second power battery (4) to supply power to the DC / DC module (1); The control device (2) controls the DC / DC module (1) to apply an alternating disturbance signal with a certain frequency to the fuel cell (6); The voltage inspection device obtains a single voltage signal and feeds back to the control device (2); The control device (2) obtains the voltage signal and the current signal, and obtains the impedance value of each single piece through FFT transformation.

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