A fuel cell multi-parameter simultaneous test tool and test method

Abstract

The application discloses a fuel cell multi-parameter simultaneous testing tool and testing method, which comprises at least one measuring subarea, each of which is provided with a first end plate, a second end plate, a current sampling resistor R, a thermocouple TC and a humidity sensitive element; the current sampling resistor R is connected in series between the first end plate and the second end plate; the thermocouple TC and the humidity sensitive element are connected in series to form a temperature and humidity detection branch; the first end of the branch is connected to the first end of the R; the second end leads out a third external lead; an alternating current excitation source, the temperature and humidity detection branch and the current sampling resistor R form a series detection loop; and the current sampling resistor R is the only shared circuit element of the subarea working current and the alternating current detection current.

Description

Technical Field

[0001] This invention relates to the field of fuel cell testing technology, and specifically to a multi-parameter simultaneous testing fixture and testing method for fuel cells. Background Technology

[0002] A fuel cell is an energy conversion device that directly converts chemical energy into electrical energy. It boasts advantages such as high efficiency and environmental friendliness, and has broad application prospects in the field of new energy. The distribution of current density, humidity, and temperature within the fuel cell is a key factor in optimizing fuel cell design and improving its performance. To gain a deeper understanding of the working mechanism of fuel cells and optimize their performance, it is necessary to simultaneously measure the local current density, humidity, and temperature parameters at various points within the fuel cell's flow field.

[0003] Currently, existing technologies typically use separate sensors to measure current density, temperature, and humidity separately; For example, Chinese patents CN201410637420.0 and CN201410637433.8 disclose related measurement schemes, which arrange current density, temperature and humidity sensors together and lead them out independently.

[0004] The existing technology has the following drawbacks: Since each sensor requires an independent lead, the number of leads increases significantly when multiple measurement points need to be arranged throughout the entire fuel cell flow field. For example, each measurement zone typically requires 4 to 6 leads. If the number of measurement zones increases, the number of leads will increase significantly, increasing the design complexity and manufacturing cost of the test fixture.

[0005] Furthermore, in the prior art, in order to avoid the superposition of various voltage signals and make them indistinguishable, each sensor is deployed independently, using isolation connection or common ground connection, and the leads of each sensor are brought out independently. There is no motivation to deliberately mix the originally independent sensor signals together. Even though the signal separation technology of electrochemical impedance spectroscopy (EIS) can theoretically separate mixed signals, this does not mean that a person skilled in the art has an incentive to mix the originally independent signals. "Whether they can be separated" and "whether they should be mixed" are two independent technical issues.

[0006] Traditional technical thinking holds that signal mixing inevitably leads to indistinguishability, and therefore there has long been a lack of technical solutions to actively superimpose multi-sensor signals at the circuit level to reduce the number of leads.

[0007] Therefore, there is a need for a multi-parameter measurement scheme for fuel cells that can overcome the technical bias of indistinguishable signal mixing, ensure measurement accuracy, and reduce the number of leads. Summary of the Invention

[0008] This invention proposes a multi-parameter simultaneous testing fixture and method for fuel cells. By using a topology design with the current sampling resistor R as the only common circuit element, combined with AC excitation signal and impedance spectrum analysis, the superposition and separation of multi-parameter signals are realized.

[0009] To achieve the above objectives, the technical solution of the present invention is as follows: A multi-parameter simultaneous testing fixture for fuel cells includes at least one measurement zone, and each measurement zone is equipped with... First end plate and second end plate; A current sampling resistor R is connected in series between the first end plate and the second end plate to convert the partitioned operating current generated by the fuel cell reaction into a voltage signal. The first end of the current sampling resistor R has a first external lead, and the second end of the current sampling resistor R has a second external lead. Thermocouple TC and humidity-sensitive element are connected in series to form a temperature and humidity detection branch. The first end of the temperature and humidity detection branch is connected to the first end of the current sampling resistor R. The second end of the temperature and humidity detection branch is a free end and a third external lead is led out. AC excitation source and voltage measuring device; The AC excitation source, the temperature and humidity detection branch, and the current sampling resistor R form a series detection circuit. The series detection circuit is used to apply an AC detection current to the temperature and humidity detection branch. The AC detection current flows through both the temperature and humidity detection branch and the current sampling resistor R. The current sampling resistor R is the only shared circuit element between the zone operating current and the AC detection current. The voltage measuring device is used to measure voltage response signals between the first and second outer leads, between the third and first outer leads, and between the third and second outer leads.

[0010] Furthermore, the first end of the temperature and humidity detection branch is connected to the first end of the current sampling resistor R through the first end plate.

[0011] Furthermore, the first end of the temperature and humidity detection branch is directly connected to the first end of the current sampling resistor R via a lead wire, without passing through the first end plate.

[0012] Furthermore, the first external lead is removed, the first end of the current sampling resistor R is connected to the first end plate and to the first end of the temperature and humidity detection branch, the second end of the current sampling resistor R is led out as a second external lead, and the second end of the temperature and humidity detection branch is led out as a third external lead.

[0013] Furthermore, the external lead of the second external lead is removed, the second end of the current sampling resistor R is connected to the second end plate, the first end of the current sampling resistor R is led out as a first external lead, and the second end of the temperature and humidity detection branch is led out as a third external lead.

[0014] A multi-parameter simultaneous testing fixture for fuel cells includes at least one measurement zone, and each measurement zone is equipped with... First end plate and second end plate; A current sampling resistor R is connected in series between the first end plate and the second end plate to convert the partitioned operating current generated by the fuel cell reaction into a voltage signal. The first end of the current sampling resistor R has a first external lead, and the second end of the current sampling resistor R has a second external lead. Thermocouple TC and humidity-sensitive element are connected in series to form a temperature and humidity detection branch. The first end of the temperature and humidity detection branch is connected to the second end of the current sampling resistor R. The second end of the temperature and humidity detection branch is a free end and a third external lead is led out. AC excitation source and voltage measuring device; The AC excitation source, the temperature and humidity detection branch, and the current sampling resistor R form a series detection circuit. The series detection circuit is used to apply an AC detection current to the temperature and humidity detection branch. The AC detection current flows through both the temperature and humidity detection branch and the current sampling resistor R. The current sampling resistor R is the only shared circuit element between the zone operating current and the AC detection current. The voltage measuring device is used to measure voltage response signals between the first and second outer leads, between the third and first outer leads, and between the third and second outer leads.

[0015] Furthermore, the first end of the temperature and humidity detection branch is connected to the second end of the current sampling resistor R through the second end plate.

[0016] Furthermore, the first end of the temperature and humidity detection branch is directly connected to the second end of the current sampling resistor R via a lead wire, without passing through the second end plate.

[0017] A multi-parameter simultaneous testing fixture for fuel cells includes at least one measurement zone, and each measurement zone is equipped with... First end plate and second end plate; A current sampling resistor R is connected in series between the first end plate and the second end plate to convert the partitioned operating current generated by the fuel cell reaction into a voltage signal. The first end of the current sampling resistor R has a first external lead, and the second end of the current sampling resistor R has a second external lead. The thermocouple TC and the humidity-sensitive element are connected in parallel to form a temperature and humidity detection branch. The first end of the temperature and humidity detection branch is a parallel common terminal and is connected to the first end of the current sampling resistor R. The second end of the temperature and humidity detection branch is a parallel free terminal and a third external lead is led out. AC excitation source and voltage measuring device; The AC excitation source, the temperature and humidity detection branch, and the current sampling resistor R form a series detection circuit. The series detection circuit is used to apply an AC detection current to the temperature and humidity detection branch. The AC detection current flows through both the temperature and humidity detection branch and the current sampling resistor R. The current sampling resistor R is the only shared circuit element between the zone operating current and the AC detection current. The voltage measuring device is used to measure voltage response signals between the first and second outer leads, between the third and first outer leads, and between the third and second outer leads.

[0018] Furthermore, the humidity-sensitive element is a proton exchange membrane resistor, and the resistance value of the proton exchange membrane resistor changes with the ambient humidity.

[0019] Furthermore, the humidity-sensitive element is a capacitive humidity-sensitive element, and the capacitance value of the capacitive humidity-sensitive element changes with the ambient humidity.

[0020] The method for simultaneous testing of multiple parameters of a fuel cell using the aforementioned fuel cell multi-parameter simultaneous testing fixture includes the following steps: Step S1) In each measurement zone, the current sampling resistor R is connected in series between the first end plate and the second end plate, the thermocouple TC is connected in series with the humidity sensing element to form a temperature and humidity detection branch, and the first end of the temperature and humidity detection branch is connected to the first end of the current sampling resistor R, so that the AC excitation source, the temperature and humidity detection branch, and the current sampling resistor R form a series detection loop, and the current sampling resistor R is the only common circuit element for the zone working current and the AC detection current. Step S2) Apply an AC excitation signal through the AC excitation source, and measure the voltage response signal between the first external lead and the second external lead, and / or between the third external lead and the first external lead, and / or between the third external lead and the second external lead through the voltage measuring device; Step S3) Based on the voltage response signal, the current density, temperature and humidity are obtained by impedance spectroscopy analysis.

[0021] The method for simultaneous testing of multiple parameters of a fuel cell using the aforementioned fuel cell multi-parameter simultaneous testing fixture includes the following steps: Step S1) In each measurement zone, the current sampling resistor R is connected in series between the first end plate and the second end plate, the thermocouple TC is connected in parallel with the humidity sensing element to form a temperature and humidity detection branch, and the first end of the temperature and humidity detection branch is connected to the first end of the current sampling resistor R, so that the AC excitation source, the temperature and humidity detection branch, and the current sampling resistor R form a series detection circuit, and the current sampling resistor R is the only common circuit element for the zone working current and the AC detection current. Step S2) Apply an AC excitation signal through the AC excitation source, and measure the voltage response signal between the first external lead and the second external lead, and / or between the third external lead and the first external lead, and / or between the third external lead and the second external lead through the voltage measuring device; Step S3) Based on the voltage response signal, the current density, temperature and humidity are obtained by impedance spectroscopy analysis.

[0022] Further, a first AC excitation signal is applied, and a first voltage response signal between the first external lead and the second external lead is measured. The current density of the measurement zone is calculated based on the first voltage response signal. A second AC excitation signal is applied, and a second voltage response signal is measured between the third external lead and the first external lead or between the third external lead and the second external lead. Based on the second voltage response signal, the DC electromotive force of the thermocouple representing temperature and the AC impedance value of the humidity-sensitive element representing humidity are separated.

[0023] Furthermore, the first AC excitation signal and the second AC excitation signal are applied simultaneously or rapidly alternately, and only the mixed voltage response signal between the third external lead and the second external lead is measured. The current density signal, temperature signal and humidity signal are obtained from the mixed voltage response signal in one go by frequency differentiation or time differentiation method.

[0024] Furthermore, when the test fixture has a first external lead, the first external lead is suspended, and the first AC excitation signal and the second AC excitation signal are applied simultaneously or rapidly alternately. Only the mixed voltage response signal between the third external lead and the second external lead is measured. The current density signal, temperature signal and humidity signal are obtained from the mixed voltage response signal in one go by frequency differentiation or time differentiation method.

[0025] Furthermore, in step S3, a frequency domain signal separation method or a time domain signal separation method is used instead of the impedance spectrum analysis method to separate the current density, temperature, and humidity from the voltage response signal.

[0026] Compared with the prior art, the present invention has the following advantages: By connecting a thermocouple and a humidity-sensitive element in series and then combining them with a current sampling resistor, multiple parameters are separated using the AC impedance spectroscopy method, reducing the number of leads for each measurement zone from 4-6 in the prior art to 2-3. It overcomes the technical bias that signals cannot be distinguished after mixing, and achieves signal superposition and separation by using the current sampling resistor R as the only common circuit element; The three-wire connection method can measure current density and temperature and humidity separately through step excitation, while the two-wire connection method can achieve simultaneous measurement of three parameters while reducing one external lead through dual excitation. By integrating the current sampling resistor, temperature sensor, and humidity sensor into the same measurement zone, synchronous acquisition of multiple parameters at the same spatial location is achieved. Humidity sensing elements are not limited to resistive types; they can be selected from either resistive or capacitive humidity sensing elements, thus expanding the applicability and implementation flexibility of the technical solution. Attached Figure Description

[0027] Figure 1 This is a circuit structure diagram of Embodiment 1 of the present invention; Figure 2 This is a circuit structure diagram of Embodiment 2 of the present invention; Figure 3 This is a circuit structure diagram of Embodiment 3 of the present invention; Figure 4 This is a circuit structure diagram of Embodiment 4 of the present invention; Figure 5 This is a circuit structure diagram of Embodiment 5 of the present invention; Figure 6 This is a circuit structure diagram of Embodiment 6 of the present invention; Figure 7 This is a circuit structure diagram of Embodiment 7 of the present invention; Figure 8 This is a circuit structure diagram of Embodiment 8 of the present invention; Figure 9 This is a circuit structure diagram of Embodiment 9 of the present invention; Figure 10 This is a circuit structure diagram of Embodiment 10 of the present invention; Figure Labels A. First end plate, B. Second end plate, R. Current sampling resistor, TC. Thermocouple Rh humidity-sensitive resistor, S1 zone current density sampling terminal, S2 signal sampling terminal G is the common potential terminal. Detailed Implementation

[0028] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] Example 1 This embodiment discloses a multi-parameter simultaneous testing fixture for fuel cells, such as... Figure 1 As shown, it includes at least one measurement zone, and each measurement zone is equipped with a first end plate A, a second end plate B, a current sampling resistor R, a thermocouple TC, and a humidity-sensitive resistor R. h .

[0030] A current sampling resistor R is connected in series between the first end plate A and the second end plate B. The zone operating current flows from the first end plate A through the current sampling resistor R and then into the second end plate B. The current sampling resistor R is used to measure the current density of the zone. The sampling resistor is connected in series in the zone current loop of the fuel cell. When the current flows through, a voltage drop proportional to the current is generated across the resistor.

[0031] One end of the current sampling resistor R is led out to the partition current density sampling terminal S1 (corresponding to the first external lead), and the other end of the current sampling resistor R is led out to the common potential terminal G (corresponding to the second external lead).

[0032] Thermocouple TC and humidity-sensitive resistor R h A series connection is formed to create a temperature and humidity series branch. Thermocouple TC generates an electromotive force when the temperatures at its two ends are different. This electromotive force is proportional to the temperature difference. Humidity-sensitive resistor R... h Used to measure humidity.

[0033] Preferably, the humidity-sensitive resistor is a proton exchange membrane (PEM membrane), whose resistance value changes with the ambient humidity; when the humidity increases, the proton conductivity of the PEM membrane increases and the resistance value decreases; conversely, when the humidity decreases, the resistance value increases.

[0034] One end of the temperature and humidity series branch is connected to the current sampling resistor R through the first terminal block A, and the other end of the temperature and humidity series branch leads out the signal sampling terminal S2 (corresponding to the third external lead).

[0035] The test fixture also includes an AC excitation source and a voltage measuring device. The AC excitation source is used to apply an AC excitation signal, and the voltage measuring device is used to measure the voltage response signal and separate the current density, temperature and humidity signals through impedance spectroscopy analysis.

[0036] This embodiment discloses a method for simultaneous testing of multiple parameters in a fuel cell. A circuit is laid out within a measurement zone of the fuel cell, consisting of a first end plate A and a second end plate B. A zone current sampling resistor R is connected between the first end plate A and the second end plate B. A thermocouple TC and a humidity-sensitive resistor R are also connected. h A temperature and humidity detection branch is formed by connecting the two circuits in series. One end of the temperature and humidity detection branch is connected to the partition current density sampling resistor R, and the other end of the temperature and humidity detection branch leads out to the signal sampling terminal S2.

[0037] One end of the partition current sampling resistor R is led out to the partition current density sampling terminal S1, and the other end of the partition current sampling resistor R is led out to the common potential terminal G. A first AC excitation signal is applied to the fuel cell, and the first voltage response signal between the common potential terminal G and the partition current density sampling terminal S1 is measured. The current density of the measurement partition is calculated based on the first voltage response signal.

[0038] In this embodiment, a corresponding sinusoidal voltage drop is generated across the current sampling resistor R. By measuring the amplitude of the AC voltage response between the common potential terminal G and the partitioned current density sampling terminal S1, and combining this with the known resistance value of the current sampling resistor R, the magnitude of the partitioned sampling current can be calculated. Then, by dividing by the area of ​​the measurement partition, the current density can be obtained.

[0039] Since the sampling current in the partition does not pass through the series circuit of the thermocouple and the humidity-sensitive resistor, the measurement of the current density is not affected by the temperature and humidity detection branch.

[0040] One end of the temperature and humidity series branch is connected to the first end plate A. A second AC excitation signal is applied to the temperature and humidity series detection branch. The second voltage response signal between the signal sampling terminal S2 and the partition current density sampling terminal S1 is measured. The thermocouple electromotive force and humidity sensitive resistance value are separated based on the second voltage response signal. The temperature and humidity of the measurement partition are then calculated.

[0041] In the temperature and humidity series detection branch, there are two different types of electrical signals: Thermocouple TC generates a DC electromotive force (or a slowly changing signal), the magnitude of which is proportional to temperature. Humidity-sensitive resistor R h It manifests as AC impedance, the value of which is related to humidity. Using the AC impedance spectroscopy method, the DC component and the AC impedance component can be separated from the mixed voltage response signal: the DC component corresponds to the electromotive force of the thermocouple, which can be converted into temperature through calibration; the AC impedance component corresponds to the resistance value of the humidity-sensitive resistor, which can be converted into humidity through calibration.

[0042] In this embodiment, each measurement zone has three leads: a common potential terminal G, a zone current density sampling terminal S1, and a signal sampling terminal S2.

[0043] It should be noted that thermocouple TC is a general term for any temperature sensing element that can convert temperature changes into electrical signals, including but not limited to thermocouples, thermistors, platinum resistance temperature sensors, etc.; humidity-sensitive resistor Rh is a general term for any humidity sensing element that can convert humidity changes into impedance changes, including but not limited to proton exchange membrane resistors, ceramic humidity sensors, polymer humidity sensors, etc.

[0044] Those skilled in the art can choose any suitable temperature and humidity sensor to replace the implementation according to actual needs, as long as it can achieve signal superposition with the current sampling resistor R at the circuit level and be restored by signal separation method.

[0045] Example 2 like Figure 2 As shown, this embodiment is similar to embodiment 1, except that one end of the temperature and humidity series branch is connected to the second end plate B, a second AC excitation signal is applied to the temperature and humidity series detection branch, the second voltage response signal between the signal sampling terminal S2 and the common potential terminal G is measured, the thermocouple electromotive force and the humidity sensitive resistance value are separated based on the second voltage response signal, and the temperature and humidity of the measurement zone are calculated.

[0046] In this embodiment, each measurement zone has three leads: a common potential terminal G, a zone current density sampling terminal S1, and a signal sampling terminal S2.

[0047] Example 3 like Figure 3 As shown, this embodiment is similar to Embodiment 1, with one end of the temperature and humidity series branch connected to the first end plate A. The difference is that the arrangement of the common potential terminal G is omitted, and the current sampling resistor R, thermocouple TC, and humidity-sensitive resistor R are replaced. h When connected in series as an integrated detection branch, the mixed voltage response signal between the signal sampling terminal S2 and the partitioned current density sampling terminal S1 can be directly measured.

[0048] By applying the first AC excitation signal and the second AC excitation signal simultaneously or rapidly alternatingly, and by using frequency differentiation or time differentiation methods, the current density signal, temperature signal, and humidity signal can be separated at once from the mixed voltage response signal between the signal sampling terminal S2 and the partitioned current density sampling terminal S1.

[0049] When performed simultaneously, the first AC excitation signal and the second AC excitation signal use different frequencies. By using the frequency differentiation method, the current density signal, temperature signal and humidity signal are separated from the mixed voltage response signal. When rapid alternation occurs, different parameters are measured in different time windows using a time-separated method.

[0050] Since the temperature and humidity series detection branch is connected in series with the current density sampling resistor, the signals of the three parameters are superimposed between the signal sampling terminal S2 and the partition current density sampling terminal S1. At this time, by applying AC excitation between the signal sampling terminal S2 and the partition current density sampling terminal S1 and measuring the voltage response, the three parameters of current density, temperature and humidity can be separated at once.

[0051] Specifically, by selecting different excitation frequencies or using multi-frequency impedance spectroscopy analysis, the voltage drop of the sampling resistor (corresponding to current density), the electromotive force of the thermocouple (corresponding to temperature), and the voltage drop of the humidity-sensitive resistor (corresponding to humidity) can be extracted respectively.

[0052] In this embodiment, each measurement zone has two leads: zone current density sampling terminal S1 and signal sampling terminal S2.

[0053] The signal separation algorithm in this embodiment is relatively complex, but by using appropriate AC excitation frequency selection and impedance spectrum analysis methods, the three parameters can still be accurately separated.

[0054] Example 4 like Figure 4 As shown, this embodiment is similar to Embodiment 2, with one end of the temperature and humidity series branch connected to the second end plate B. The difference is that the arrangement of the common potential terminal G is omitted, and the current sampling resistor R, thermocouple TC, and humidity-sensitive resistor R are replaced. h When connected in series as an integrated detection branch, the mixed voltage response signal between the signal sampling terminal S2 and the partitioned current density sampling terminal S1 can be directly measured.

[0055] By applying the first AC excitation signal and the second AC excitation signal simultaneously or rapidly alternatingly, and by using frequency differentiation or time differentiation methods, the current density signal, temperature signal, and humidity signal can be separated at once from the mixed voltage response signal between the signal sampling terminal S2 and the partitioned current density sampling terminal S1.

[0056] In this embodiment, each measurement zone has two leads: zone current density sampling terminal S1 and signal sampling terminal S2.

[0057] The signal separation algorithm in this embodiment is relatively complex, but by using appropriate AC excitation frequency selection and impedance spectrum analysis methods, the three parameters can still be accurately separated.

[0058] Example 5 like Figure 5 As shown, this embodiment is similar to embodiment 1, except that one end of the temperature and humidity series branch (one end of the thermocouple TC) is connected to a position closer to the sampling resistor R through a lead wire, instead of passing through the first end plate A.

[0059] In Example 1, one end of the temperature and humidity series branch is connected to the sampling resistor R through the first terminal plate A. The large current flowing directly through the current collector will cause voltage deviation and reduce measurement accuracy. This example aims to avoid this deviation.

[0060] Example 6 like Figure 6 As shown, this embodiment is similar to embodiment 2, except that one end of the temperature and humidity series branch (one end of the thermocouple TC) is connected to a position closer to the current sampling resistor R through a lead wire, instead of passing through the second end plate B.

[0061] In Example 2, one end of the temperature and humidity series branch is connected to the sampling resistor R through the second terminal plate B. The large current flowing directly through the current collector will cause voltage deviation and reduce measurement accuracy. This example aims to avoid this deviation.

[0062] Example 7 like Figure 7 As shown, this embodiment is similar to embodiment 3, except that one end of the temperature and humidity series branch (one end of the thermocouple TC) is connected to a position closer to the sampling resistor R through a lead wire, instead of passing through the first end plate A.

[0063] In Example 3, one end of the temperature and humidity series branch is connected to the sampling resistor R through the first terminal plate A. The large current flowing directly through the current collector will cause voltage deviation and reduce measurement accuracy. This example aims to avoid this deviation.

[0064] Example 8 like Figure 8 As shown, this embodiment is similar to embodiment 4, except that one end of the temperature and humidity series branch (one end of the thermocouple TC) is connected to a position closer to the sampling resistor R through a lead wire, instead of passing through the second end plate B.

[0065] In Example 4, one end of the temperature and humidity series branch is connected to the current sampling resistor R through the second terminal plate B. The large current flowing directly through the current collector will cause voltage deviation and reduce measurement accuracy. This example aims to avoid this deviation.

[0066] Example 9 like Figure 9 As shown, this embodiment is similar to Embodiment 7, except that the thermocouple TC and the humidity-sensitive resistor R are different. h in parallel.

[0067] The current sampling resistor R is connected to the first end plate A and the second end plate B respectively. The working current flows from the first end plate A through the current sampling resistor R to the second end plate B. The end of the current sampling resistor R closest to the second end plate B leads out the partition current density sampling terminal S1. Thermocouple TC and humidity-sensitive resistor R hThe two ends are connected to each other to form a parallel branch. One end of the parallel branch is connected to the current sampling resistor R, and the other end is led out to the signal sampling terminal S2. The branch of the current sampling resistor R can realize the acquisition of the reference electrical signal, and the thermocouple TC and the humidity-sensitive resistor R are set in parallel. h The ambient temperature and humidity parameters are collected synchronously, and the two independently changing sensor signals are output through the partition current density sampling terminal S1 and the signal sampling terminal S2 respectively.

[0068] Example 10 like Figure 10 As shown, this embodiment is similar to Embodiment 8, except that the thermocouple TC and the humidity-sensitive resistor R are different. h in parallel.

[0069] The two ends of the current sampling resistor R are connected to the first end plate A and the second end plate B respectively. The working current flows from the first end plate A through the current sampling resistor R to the second end plate B. The end of the current sampling resistor R closest to the first end plate A leads out the partition current density sampling terminal S1. Thermocouple TC and humidity-sensitive resistor R h The two ends are connected to each other to form a parallel branch. One end of the parallel branch is connected to the current sampling resistor R, and the other end is led out to the signal sampling terminal S2. The branch of the current sampling resistor R can realize the acquisition of the reference electrical signal, and the thermocouple TC and the humidity-sensitive resistor R are set in parallel. h The ambient temperature and humidity parameters are collected synchronously, and the two independently changing sensor signals are output through the partition current density sampling terminal S1 and the signal sampling terminal S2 respectively.

[0070] This embodiment and Embodiment 9 are intended to illustrate that the signal superposition concept of the present invention is not limited to thermocouple TC and humidity-sensitive resistor R. h The series connection, parallel connection, or other combination methods can also achieve the superposition and separation of multi-parameter signals, and these variations all fall within the protection scope of this invention.

[0071] Comparative Example Using the existing independent lead scheme, N measurement zones are arranged on the same fuel cell. If each sensor uses an independent + / - double lead connection (not sharing a ground), then each zone requires 6 leads: 1 positive and 1 negative for current sampling, 1 positive and 1 negative for temperature, and 1 positive and 1 negative for humidity. If a common ground connection is used, then each zone requires 4 leads: 1 common ground wire + 3 signal wires.

[0072] Taking N=64 measurement zones as an example, the existing independent lead method requires a total of 384 leads (64×6), and the common ground method requires a total of 256 leads (64×4).

[0073] Using the scheme of Example 1, a combined temperature and humidity detection branch scheme is adopted, with 3 leads per zone, requiring a total of 3N=192 leads, which is 50% less than the independent lead method and 25% less than the common ground method.

[0074] The scheme of Example 3 adopts an integrated detection branch scheme, with 2 leads per zone, requiring a total of 2N=128 leads, which is 67% less than the independent lead method and 50% less than the common ground method.

[0075] This invention significantly reduces the number of leads, lowers the design complexity, manufacturing cost, and number of sealing perforations of the test fixture, and improves the sealing performance and test reliability of the fuel cell.

[0076] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A multi-parameter simultaneous testing fixture for fuel cells, characterized in that, Includes at least one measurement zone, and each measurement zone is provided with First end plate and second end plate; A current sampling resistor R is connected in series between the first end plate and the second end plate to convert the partitioned operating current generated by the fuel cell reaction into a voltage signal. The first end of the current sampling resistor R has a first external lead, and the second end of the current sampling resistor R has a second external lead. Thermocouple TC and humidity-sensitive element are connected in series to form a temperature and humidity detection branch. The first end of the temperature and humidity detection branch is connected to the first end of the current sampling resistor R. The second end of the temperature and humidity detection branch is a free end and a third external lead is led out. AC excitation source and voltage measuring device; The AC excitation source, the temperature and humidity detection branch, and the current sampling resistor R form a series detection circuit. The series detection circuit is used to apply an AC detection current to the temperature and humidity detection branch. The AC detection current flows through both the temperature and humidity detection branch and the current sampling resistor R. The current sampling resistor R is the only shared circuit element between the zone operating current and the AC detection current. The voltage measuring device is used to measure voltage response signals between the first and second outer leads, between the third and first outer leads, and between the third and second outer leads.

2. The fuel cell multi-parameter simultaneous testing fixture according to claim 1, characterized in that, The first end of the temperature and humidity detection branch is connected to the first end of the current sampling resistor R through the first end plate.

3. The fuel cell multi-parameter simultaneous testing fixture according to claim 1, characterized in that, The first end of the temperature and humidity detection branch is directly connected to the first end of the current sampling resistor R via a lead wire, without passing through the first end plate.

4. The fuel cell multi-parameter simultaneous testing fixture according to claim 1, characterized in that, The first external lead is removed, the first end of the current sampling resistor R is connected to the first end plate and to the first end of the temperature and humidity detection branch, the second end of the current sampling resistor R is led out as a second external lead, and the second end of the temperature and humidity detection branch is led out as a third external lead.

5. The fuel cell multi-parameter simultaneous testing fixture according to claim 1, characterized in that, The second external lead is removed, the second end of the current sampling resistor R is connected to the second end plate, the first end of the current sampling resistor R is led out as a first external lead, and the second end of the temperature and humidity detection branch is led out as a third external lead.

6. A multi-parameter simultaneous testing fixture for fuel cells, characterized in that, Includes at least one measurement zone, and each measurement zone is provided with First end plate and second end plate; A current sampling resistor R is connected in series between the first end plate and the second end plate to convert the partitioned operating current generated by the fuel cell reaction into a voltage signal. The first end of the current sampling resistor R has a first external lead, and the second end of the current sampling resistor R has a second external lead. Thermocouple TC and humidity-sensitive element are connected in series to form a temperature and humidity detection branch. The first end of the temperature and humidity detection branch is connected to the second end of the current sampling resistor R. The second end of the temperature and humidity detection branch is a free end and a third external lead is led out. AC excitation source and voltage measuring device; The AC excitation source, the temperature and humidity detection branch, and the current sampling resistor R form a series detection circuit. The series detection circuit is used to apply an AC detection current to the temperature and humidity detection branch. The AC detection current flows through both the temperature and humidity detection branch and the current sampling resistor R. The current sampling resistor R is the only shared circuit element between the zone operating current and the AC detection current. The voltage measuring device is used to measure voltage response signals between the first and second outer leads, between the third and first outer leads, and between the third and second outer leads.

7. The fuel cell multi-parameter simultaneous testing fixture according to claim 6, characterized in that, The first end of the temperature and humidity detection branch is connected to the second end of the current sampling resistor R through the second end plate.

8. The fuel cell multi-parameter simultaneous testing fixture according to claim 6, characterized in that, The first end of the temperature and humidity detection branch is directly connected to the second end of the current sampling resistor R via a lead wire, without passing through the second end plate.

9. A multi-parameter simultaneous testing fixture for fuel cells, characterized in that, Includes at least one measurement zone, and each measurement zone is provided with First end plate and second end plate; A current sampling resistor R is connected in series between the first end plate and the second end plate to convert the partitioned operating current generated by the fuel cell reaction into a voltage signal. The first end of the current sampling resistor R has a first external lead, and the second end of the current sampling resistor R has a second external lead. The thermocouple TC and the humidity-sensitive element are connected in parallel to form a temperature and humidity detection branch. The first end of the temperature and humidity detection branch is a parallel common terminal and is connected to the first end of the current sampling resistor R. The second end of the temperature and humidity detection branch is a parallel free terminal and a third external lead is led out. AC excitation source and voltage measuring device; The AC excitation source, the temperature and humidity detection branch, and the current sampling resistor R form a series detection circuit. The series detection circuit is used to apply an AC detection current to the temperature and humidity detection branch. The AC detection current flows through both the temperature and humidity detection branch and the current sampling resistor R. The current sampling resistor R is the only shared circuit element between the zone operating current and the AC detection current. The voltage measuring device is used to measure voltage response signals between the first and second outer leads, between the third and first outer leads, and between the third and second outer leads.

10. The fuel cell multi-parameter simultaneous testing fixture according to any one of claims 1 to 9, characterized in that, The humidity-sensitive element is a proton exchange membrane resistor, and the resistance of the proton exchange membrane resistor changes with the ambient humidity.

11. The fuel cell multi-parameter simultaneous testing fixture according to any one of claims 1 to 9, characterized in that, The humidity-sensitive element is a capacitive humidity-sensitive element, and the capacitance value of the capacitive humidity-sensitive element changes with the ambient humidity.

12. A method for simultaneous testing of multiple parameters of a fuel cell using the fuel cell multi-parameter simultaneous testing fixture described in any one of claims 1 to 8, characterized in that, Includes the following steps: Step S1) In each measurement zone, the current sampling resistor R is connected in series between the first end plate and the second end plate, the thermocouple TC is connected in series with the humidity sensing element to form a temperature and humidity detection branch, and the first end of the temperature and humidity detection branch is connected to the first end of the current sampling resistor R, so that the AC excitation source, the temperature and humidity detection branch, and the current sampling resistor R form a series detection loop, and the current sampling resistor R is the only common circuit element for the zone working current and the AC detection current. Step S2) Apply an AC excitation signal through the AC excitation source, and measure the voltage response signal between the first external lead and the second external lead, and / or between the third external lead and the first external lead, and / or between the third external lead and the second external lead through the voltage measuring device; Step S3) Based on the voltage response signal, the current density, temperature and humidity are obtained by impedance spectroscopy analysis.

13. A method for simultaneous testing of multiple parameters of a fuel cell using the fuel cell multi-parameter simultaneous testing fixture described in claim 9, characterized in that, Includes the following steps: Step S1) In each measurement zone, the current sampling resistor R is connected in series between the first end plate and the second end plate, the thermocouple TC is connected in parallel with the humidity sensing element to form a temperature and humidity detection branch, and the first end of the temperature and humidity detection branch is connected to the first end of the current sampling resistor R, so that the AC excitation source, the temperature and humidity detection branch, and the current sampling resistor R form a series detection circuit, and the current sampling resistor R is the only common circuit element for the zone working current and the AC detection current. Step S2) Apply an AC excitation signal through the AC excitation source, and measure the voltage response signal between the first external lead and the second external lead, and / or between the third external lead and the first external lead, and / or between the third external lead and the second external lead through the voltage measuring device; Step S3) Based on the voltage response signal, the current density, temperature and humidity are obtained by impedance spectroscopy analysis.

14. The method for simultaneous testing of multiple parameters of a fuel cell according to claim 12 or 13, characterized in that, A first AC excitation signal is applied, and a first voltage response signal between the first external lead and the second external lead is measured. The current density of the measurement zone is calculated based on the first voltage response signal. A second AC excitation signal is applied, and a second voltage response signal is measured between the third external lead and the first external lead or between the third external lead and the second external lead. Based on the second voltage response signal, the DC electromotive force of the thermocouple representing temperature and the AC impedance value of the humidity-sensitive element representing humidity are separated.

15. The method for simultaneous testing of multiple parameters of a fuel cell according to claim 12 or 13, characterized in that, The first AC excitation signal and the second AC excitation signal are applied simultaneously or rapidly alternately. Only the mixed voltage response signal between the third external lead and the second external lead is measured. The current density signal, temperature signal and humidity signal are obtained from the mixed voltage response signal in one go by frequency differentiation or time differentiation method.

16. The method for simultaneous testing of multiple parameters of a fuel cell according to claim 12 or 13, characterized in that, When the test fixture has a first external lead, the first external lead is suspended, and the first AC excitation signal and the second AC excitation signal are applied simultaneously or rapidly alternately. Only the mixed voltage response signal between the third external lead and the second external lead is measured. The current density signal, temperature signal and humidity signal are obtained from the mixed voltage response signal in one go by frequency differentiation or time differentiation method.

17. The method for simultaneous testing of multiple parameters of a fuel cell according to claim 12 or 13, characterized in that, In step S3, a frequency domain signal separation method or a time domain signal separation method is used instead of the impedance spectrum analysis method to separate the current density, temperature and humidity from the voltage response signal.

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