CN211629223U

CN211629223U - Detection assembly for fuel cell stack operation state, fuel cell and vehicle

Info

Publication number: CN211629223U
Application number: CN202020359322.6U
Authority: CN
Inventors: 段羽; 牛振华
Original assignee: Weishi Energy Technology Co Ltd
Current assignee: Weishi Energy Technology Co Ltd
Priority date: 2020-03-20
Filing date: 2020-03-20
Publication date: 2020-10-02
Anticipated expiration: 2030-03-20

Abstract

Detection subassembly, fuel cell and vehicle of fuel cell stack operating condition, the detection subassembly includes: the current differential sensor is electrically connected with the fuel cell stack and is suitable for reading the current of the fuel cell stack and carrying out derivation on the current; the Fourier analyzer is electrically connected to the current differential sensor and is adapted to perform harmonic distortion analysis based on the differential of the current. Therefore, the differential current of the fuel cell stack is measured by arranging the current differential sensor, on one hand, the detection precision of the detection assembly can be improved, and the cost of the detection assembly is reduced; on the other hand, the current differential sensor occupies small space, has lower cost compared with the prior art, and meets the use requirement; and the impedance of the fuel cell stack and the impedance of the single battery do not need to be measured to draw a reference curve, and the measurement time and the mapping cost in the early stage can be reduced on the premise of meeting the detection precision.

Description

Detection assembly for fuel cell stack operation state, fuel cell and vehicle

Technical Field

The utility model belongs to the technical field of the fuel cell technique and specifically relates to a detection subassembly, fuel cell and vehicle of fuel cell stack running state are related to.

Background

In the related art, a fuel cell stack is formed by connecting a plurality of unit cells in series. The output voltage range of the single battery is 0.7V-1.0V, the single voltage is small, and a plurality of single batteries are combined together in a series connection mode to obtain the required high voltage, and because the fuel battery stack is formed by connecting a plurality of single batteries in series, once one single battery fails, the failure of the whole fuel battery stack is caused, so the detection of the operation state of the single battery is necessary.

One conventional method of detecting the voltage of the single cell is to detect the voltage of the single cell, and the voltage of the single cell is measured by detecting the voltage of each single cell (for example, 500 single cells) or detecting each single cell (for example, 250 single cells) of the fuel cell stack. Multichannel voltage measurement is extremely costly, and instrumentation is heavy and space consuming (circuitry, a/D converters, high voltage devices in limited space, electronic collection devices with high common mode range).

That is, multi-channel voltage measurements are extremely expensive, the equipment takes up space and is of a large quality (circuits, connectors, a/D converters, high voltages in confined spaces, and acquisition electronics with high common mode range), and it is difficult to meet the requirements of mass production.

Another way of detecting this is to measure the impedance of the fuel cell stack over a range of frequencies and compare it to a reference curve.

The change of the characteristic frequency of the impedance curve can reflect the change of the cathode, the anode and the proton exchange membrane of the fuel cell. This method is based on the fact that: the equivalent circuit of the fuel cell stack is a series-parallel circuit of first-order low-pass filters having greatly different cut-off frequencies, thereby providing the required selectivity. The monitoring mode based on the impedance spectrum is used for diagnosing the condition of the electric pile according to the stored reference value or reference curve. These references represent target parameter values for "healthy" (i.e., non-zero operating conditions), which makes it necessary to know in advance all the operating conditions of the stack under given conditions (pressure, temperature, humidity, etc.) and to store these condition data for each fuel cell.

That is, the sample capacity when the reference curve is plotted is large, a lot of time cost and measurement cost are required for calibrating and acquiring the relevant data of each unit cell, and in the practical application of the fuel cell stack composed of a plurality of unit cells, not only the defect of the unit cell but also the condition causing the defect need to be identified, so that an appropriate countermeasure can be taken. In extreme cases, the entire stack needs to be processed offline. Methods based on reference curves or certain statistical distribution assumptions do not guarantee reliable identification of such cases.

SUMMERY OF THE UTILITY MODEL

The utility model discloses aim at solving one of the technical problem that exists among the prior art at least. Therefore, the utility model aims to provide a detection component for the operation state of the fuel cell stack, which not only occupies small space and meets the use requirement; and the measurement precision is high and the cost is low.

The utility model further provides an adopt above-mentioned determine module's fuel cell.

The utility model also provides a vehicle of having above-mentioned fuel cell.

The detection assembly for the operating state of the fuel cell stack according to the embodiment of the first aspect of the present invention comprises: a current differential sensor electrically connected to the fuel cell stack and adapted to read and derive a current of the fuel cell stack; the Fourier analyzer is electrically connected with the current differential sensor and is suitable for harmonic distortion analysis according to the differential of the current.

According to the embodiment of the utility model, the differential current of the fuel cell stack is measured by arranging the current differential sensor, on one hand, the differential current measured by the current differential sensor can reflect more state information of the fuel cell stack, the detection precision of the detection assembly can be improved, and the cost of the detection assembly is reduced; on the other hand, the current differential sensor occupies small space, has lower cost compared with the prior art, and meets the use requirement; and the impedance of the fuel cell stack and the impedance of the single battery do not need to be measured to draw a reference curve, and the measurement time and the mapping cost in the early stage can be reduced on the premise of meeting the detection precision.

According to some embodiments of the invention, the current differential sensor is configured as a hand wound sensor.

In some embodiments, the current differential sensor comprises: the insulated wire winding device comprises a laying pipe and an insulated wire, wherein the insulated wire is manually wound on the laying pipe.

Further, the detection assembly further comprises: a current sensor and a voltmeter, both electrically connected to the fuel cell stack.

Further, a first switch is arranged between the voltmeter and the current sensor.

Further, a second switch is arranged between the voltmeter and the fuel cell stack.

In some embodiments, a protection circuit is disposed between the current sensor and the voltmeter, and the protection circuit is connected in parallel with the first switch.

Further, the protection circuit includes: a third switch and a pre-charge resistor connected in series.

The fuel cell according to an embodiment of the second aspect of the present invention includes: the fuel cell stack structure comprises a plurality of detection assemblies in the above embodiments and a plurality of fuel cell stacks, wherein each fuel cell stack is correspondingly provided with one detection assembly.

According to the utility model discloses vehicle of third aspect embodiment includes: the fuel cell described in the above embodiment.

Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.

Drawings

The above and/or additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

FIG. 1 is a schematic diagram of a sensing assembly mated with a fuel cell stack in accordance with an embodiment of the present invention;

fig. 2 is a schematic diagram of a current differential sensor of a detection assembly according to an embodiment of the present invention;

fig. 3 is another schematic diagram of a current differential sensor of a sensing assembly according to an embodiment of the present invention.

Fig. 4 and 5 are a spectrum diagram of a conventional current sensor and a spectrum diagram of a current differential sensor according to the present embodiment, respectively.

Reference numerals:

the detection assembly 100 is provided with a detection component,

a current sensor 20, a current differential sensor 10, a laying pipe 11, an insulated wire 12,

the Fourier analyzer 30, the voltmeter 40, the first switch 50, the second switch 60, the third switch 70, and the pre-charging resistor 80.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are exemplary only for the purpose of explaining the present invention, and should not be construed as limiting the present invention.

A detection assembly 100 according to an embodiment of the present invention is described below with reference to fig. 1-5.

As shown in fig. 1, a fuel cell stack operating state detection assembly 100 according to an embodiment of the present invention includes: a current differential sensor 10 and a fourier analyzer 30, the current differential sensor 10 being electrically connected to the fuel cell stack and adapted to read the current of the fuel cell stack and to derive the current; the fourier analyzer 30 is electrically connected to the current differential sensor 10 and is adapted to perform harmonic distortion analysis based on the differential of the current.

First, it can be appreciated that during operation of the fuel cell stack, the following may occur:

1) insufficient reaction of hydrogen at the anode or oxygen at the cathode (i.e., insufficient reaction due to hydrogen-oxygen stoichiometry issues) results in: the U/I (voltage/current) characteristic has been degraded at a small current.

2) When the proton exchange membrane is short-circuited or short-circuited with gas, the voltage at 0 f is changed.

3) Electrode aging effect: the voltage/current characteristics are significantly degraded and the ohmic resistance is increased due to the corrosion aging effect.

That is to say, during the operation of the fuel cell stack, the specific characteristic when the fault occurs is the change of the voltage or the current, however, in some special cases, the change of the current or the change of the voltage is not obvious, and based on this, the embodiment improves the detection accuracy by collecting the differential information of the current and performing fourier analysis on the differential information of the current.

In which the dc current signal generated from the fuel cell stack may have some noise, if we directly use the current sensor to measure the current, it is difficult to amplify the inherent noise in the signal, and no more information about the operating state of the fuel cell stack can be obtained, and the health condition of the stack can not be obtained by analyzing the current signal.

The utility model discloses an use current differential sensor 10 to measure the differential current that comes from the fuel cell stack, the visual amplification comes from the noise of fuel cell stack to if there is any change in the ordinary noise mode in the current differential signal, probably trigger the unusual warning of relevant galvanic pile state, and then carry out galvanic pile fault analysis through current differential signal, in order to draw the running state parameter and other fuel cell stack parameters of relevant battery cell.

In summary, according to the detection assembly 100 of the present invention, the differential current of the fuel cell stack is measured by the current differential sensor 10, on one hand, the differential current measured by the current differential sensor 10 can reflect more state information of the fuel cell stack, so as to improve the detection accuracy of the detection assembly 100 and reduce the cost of the detection assembly 100; on the other hand, the current differential sensor 10 occupies a small space, has lower cost compared with the prior art, and meets the use requirement; and the impedance of the fuel cell stack and the impedance of the single battery do not need to be measured to draw a reference curve, and the measurement time and the mapping cost in the early stage can be reduced on the premise of meeting the detection precision.

As shown in fig. 2 and 3, according to some embodiments of the present invention, current differential sensor 10 is configured as a hand-wound sensor.

Wherein the current differential sensor 10 includes: a laying pipe 11 and an insulated wire 12, wherein the insulated wire 12 is manually wound on the laying pipe 11.

Specifically, referring to fig. 4 and 5, fig. 4 is a graph showing a change in current flowing out of a vehicle through a current sensor, and fig. 5 is a graph showing di/dt (i.e., a differential current graph) measured by the current differential sensor 10 according to the present embodiment. It is known that when the amplitude of the current is as low as the mA level, the harmonic amplitude variation of the current variation graph is too small to capture, and the differential current graph can improve the harmonic amplitude variation, so as to improve the data capture quality, so as to provide more data for the harmonic distortion analysis, thereby improving the detection accuracy.

Further, the detecting assembly 100 further includes: the fuel cell system comprises a current sensor 20 and a voltmeter 40, wherein the current sensor 20 and the voltmeter 40 are electrically connected with the fuel cell stack, a first switch 50 is arranged between the voltmeter 40 and the current sensor 20, and a second switch 60 is arranged between the voltmeter 40 and the fuel cell stack. Therefore, the switch closing state can be adjusted according to the use requirement so as to collect current and voltage.

In some embodiments, a protection circuit is provided between the current sensor 20 and the voltmeter 40, and the protection circuit is connected in parallel with the first switch 50.

Wherein, the protection circuit includes: a third switch 70 and a pre-charge resistor 80 connected in series. Thus, the safety of use of the detection unit 100 can be improved by providing the protection circuit.

Next, a specific operation of the detecting member 100 of the present embodiment will be specifically described.

1) Current differential sensor 10 the rate of change of the combined ac and dc current output by the vehicle fuel cell stack (i.e., the differential current);

2) capturing lower amplitudes of the ac electrical signal according to the harmonic distortion analysis under optimized fuel cell stack dynamics as described in fig. 5;

3) the fourier analyzer 30 acquires harmonics with higher accuracy to improve the accuracy of harmonic distortion analysis.

In summary, the detection assembly 100 of the present embodiment only needs to collect the voltage and current derivatives of the fuel cell, and the whole function can be integrated on the fuel cell, so that the cost is low, the benefit is high, and the data collection precision can be improved.

The fuel cell according to an embodiment of the second aspect of the present invention includes: a plurality of the detecting assemblies 100 in the above embodiments, and a plurality of fuel cell stacks, each of which is correspondingly provided with one detecting assembly 100.

According to the utility model discloses fuel cell, each fuel cell stack all sets up detection assembly 100, can real-time detection fuel cell's running state to improve fuel cell's job stabilization nature.

It is understood that the differential current provided by the detection assembly 100 of the present embodiment can be obtained by the battery controller to effectively cope with emergency situations.

According to the utility model discloses vehicle of third aspect embodiment includes: the fuel cell in the above embodiment.

According to the utility model discloses the vehicle adopts above-mentioned fuel cell, and fuel cell optimizes according to the transient state operating condition of vehicle to the robustness to electronic interference and noise impact has been developed, makes the safety in utilization and the stability of the vehicle of this embodiment higher.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", and the like, indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for convenience of description and simplicity of description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore, should not be construed as limiting the present invention.

In the description of the present invention, "the first feature" and "the second feature" may include one or more of the features.

In the description of the present invention, "a plurality" means two or more.

In the description of the present invention, the first feature "on" or "under" the second feature may include the first and second features being in direct contact, and may also include the first and second features being in contact with each other not directly but through another feature therebetween.

In the description of the invention, the first feature being "on", "above" and "above" the second feature includes the first feature being directly above and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an illustrative embodiment," "an example," "a specific example," or "some examples" or the like mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

While embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that: various changes, modifications, substitutions and alterations can be made to the embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A fuel cell stack operating condition detection assembly (100), comprising:

a current differential sensor (10), said current differential sensor (10) being electrically connected to said fuel cell stack and adapted to read and differentiate a current of said fuel cell stack; and

a Fourier analyzer (30), said Fourier analyzer (30) being electrically connected to said current differential sensor (10) and adapted to perform harmonic distortion analysis based on the differential of said current.

2. The stack operating state detecting assembly (100) according to claim 1, wherein the current differential sensor (10) is configured as a manual wound sensor.

3. The stack operating state detecting assembly (100) according to claim 2, wherein the current differential sensor (10) includes: a laying pipe (11) and an insulated wire (12), wherein the insulated wire (12) is manually wound on the laying pipe (11).

4. The stack operating state detecting assembly (100) according to claim 1, wherein the detecting assembly (100) further comprises: a current sensor (20) and a voltmeter (40), the current sensor (20) and the voltmeter (40) both being electrically connected to the fuel cell stack.

5. The stack operating state detecting assembly (100) according to claim 4, wherein a first switch (50) is provided between the voltmeter (40) and the current sensor (20).

6. The stack operating state detection assembly (100) according to claim 4, wherein a second switch (60) is provided between the voltmeter (40) and the fuel cell stack.

7. The stack operating state detecting assembly (100) according to claim 5, wherein a protection circuit is provided between the current sensor (20) and the voltmeter (40), and the protection circuit is connected in parallel with the first switch (50).

8. The stack operating state detecting assembly (100) according to claim 7, wherein the protection circuit comprises: a third switch (70) and a pre-charge resistor (80) connected in series.

9. A fuel cell, comprising:

a plurality of detection assemblies (100) according to any one of claims 1-8; and

the fuel cell system comprises a plurality of fuel cell stacks, wherein each fuel cell stack is correspondingly provided with one detection assembly (100).

10. A vehicle, characterized by comprising: the fuel cell of claim 9.