Detection circuit of fuel cell and fuel cell system

Abstract

The present application provides a fuel cell detection circuit and a fuel cell system, the detection circuit comprising: a first generation module for generating a constant current, the output end of the first generation module being connected with a first stack interface; the first detection interface is connected with the first end of the first resistor module, the second end of the first resistor module is connected with a reference grounding end, the first end of the first measurement module is connected with the first detection interface, and the second end of the first measurement module is connected with the second detection interface. The first measurement module is used for measuring the voltage between the first detection interface and the second detection interface, when virtual connection occurs in the first connection line, the connection resistance of the first connection line is increased and unstable, the constant current flows through the first connection line to generate voltage change, and the measurement result of the first measurement module can reflect the voltage change caused by virtual connection.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of fuel cell detection, in particular to a detection circuit of a fuel cell and a fuel cell system. BACKGROUND

[0002] The fuel cell system comprises a stack, and fuel is subjected to an electrochemical reaction in the stack to generate electric energy.

[0003] As shown in the related art, Figure 1 The fuel cell system further comprises a detection device, wherein the stack is provided with a stack interface 010, the detection device is provided with a detection interface 020, the detection interface 020 is connected to the stack interface 010 through a connecting line, and a voltage detection module 030 measures the voltage of a battery cell 040 to be measured, so that the stack can be controlled according to the measurement result, for example, the stack is purged. In the related art, there may be a virtual connection between the stack interface and the connecting line, which will affect the accuracy of the aforementioned measurement result, and if the stack is controlled accordingly, the working efficiency of the fuel cell system may be affected.

[0004] Further, in view of the problems in the related art, the applicant applied for a battery cell detection circuit and a fuel cell detection device (application number 202422405532.5) at an earlier application date to solve the problem of virtual connection of the line; the present application aims to provide a technical solution different from the earlier application. CONTENT OF THE UTILITY MODEL

[0005] The present application provides a detection circuit of a fuel cell and a fuel cell system, which aims to detect the virtual connection of the connecting line.

[0006] The first aspect of the embodiment of the application provides a detection circuit of a fuel cell. The stack comprises a first battery cell, a first stack interface connected to a positive electrode of the first battery cell, a second stack interface connected to a negative electrode of the first battery cell, a first detection interface connected to the first stack interface through a first connecting line, and a second detection interface connected to the second stack interface through a second connecting line. The detection circuit comprises: a first generation module configured to generate a constant current, wherein an output end of the first generation module is connected to the first stack interface; a first resistance module, wherein the first detection interface is connected to a first end of the first resistance module, and a second end of the first resistance module is connected to a reference ground end; a first ratio value of an allowable voltage deviation of the first battery cell to a reference voltage of the first battery cell is less than a second ratio value of an internal resistance of the first battery cell to a resistance value of the first resistance module; and a first measurement module, wherein a first end of the first measurement module is connected to the first detection interface, and a second end of the first measurement module is connected to the second detection interface, and the first measurement module is configured to measure a voltage between the first detection interface and the second detection interface, and a ratio of an allowable connection resistance of the first connecting line to the resistance value of the first resistance module is lower than a measurement resolution of the first measurement module.

[0007] In the embodiment of the application, when the stack is working, the voltage of the first battery cell can be inspected, the first generation module generates a constant current, and the first measurement module measures the voltage of the first battery cell. When the first connecting line is normally connected, the connection resistance of the first connecting line is less than the allowable connection resistance, the voltage change of the constant current flowing through the first connecting line is very small and stable, and the measurement result of the first measurement module can normally feedback the voltage of the first battery cell. When the first connecting line is virtually connected, the connection resistance of the first connecting line increases and is unstable, the constant current flowing through the first connecting line will cause a voltage change. Since the ratio of the allowable connection resistance of the first connecting line to the resistance value of the first resistance module is lower than the measurement resolution of the first measurement module, and the ratio of the internal resistance of the first battery cell to the resistance value of the first resistance module is less than the first ratio value, the measurement result of the first measurement module can reflect the voltage change caused by the virtual connection.

[0008] In some examples of the first aspect of the embodiments of the present application, the stack further comprises a second battery cell, the negative electrode of the first battery cell is connected to the positive electrode of the second battery cell, the third detection interface is connected to the negative electrode of the second battery cell, and the detection circuit of the fuel cell further comprises: a second generation module configured to generate a constant current, an output end of the second generation module being connected to the second stack interface; a second resistance module, the second detection interface being connected to a first end of the second resistance module, a second end of the second resistance module being connected to the reference ground end, a ratio of the allowable voltage deviation of the second battery cell to the reference voltage of the second battery cell being a second ratio value, and a ratio of the internal resistance of the second battery cell to the resistance value of the second resistance module being less than the second ratio value; and a second measurement module, a first end of the second measurement module being connected to the second detection interface, a second end of the second measurement module being connected to the third detection interface, and the second measurement module being configured to measure the voltage between the second detection interface and the third detection interface, a ratio of the allowable connection resistance of the second connection line to the resistance value of the second resistance module being lower than the measurement resolution of the second measurement module.

[0009] In the embodiments of the present application, when the stack is working, the virtual connection of the first connection line can be detected according to the measurement result of the first measurement module, and similarly, the virtual connection of the second connection line can be detected according to the measurement result of the second measurement module. When the virtual connection occurs in the connection line of the first battery cell, the connection line in which the virtual connection occurs can be determined according to the measurement result of the first measurement module and the measurement result of the second measurement module.

[0010] In some examples of the first aspect of the embodiments of the present application, the detection circuit of the fuel cell further comprises: a first switch module, the first resistance module being connected to a first end of the first switch module, a second end of the first switch module being connected to the reference ground end, and the first switch module being configured to control the on-off between the first resistance module and the reference ground end; a second switch module, the second resistance module being connected to a first end of the second switch module, a second end of the second switch module being connected to the reference ground end, and the second switch module being configured to control the on-off between the second resistance module and the reference ground end; and the first switch module and the second switch module being coupled.

[0011] In the embodiments of the present application, when the first switch module is in the on state, the first resistance module is connected to the ground end, and the first generation module and the first resistance module form a loop. When the first switch module is in the off state, the aforementioned loop is disconnected. If the first connection line has a virtual connection, a relatively large voltage change will occur when the constant current flows through the first connection line. Therefore, the difference between the measurement results of the first measurement module in the on state and the off state of the first switch module is relatively large. If the first connection line has no virtual connection, a relatively small voltage change will occur when the constant current flows through the first connection line. Therefore, the difference between the measurement results of the first measurement module in the on state and the off state of the first switch module is relatively small. In this way, the detection efficiency of the virtual connection can be improved.

[0012] In the embodiment of the present application, when the second switch module is in the on state, the second resistance module is connected with the ground terminal, and the second generation module and the second resistance module form a loop. When the second switch module is in the off state, the aforementioned loop is disconnected. If the second connection line is virtually connected, a constant current flowing through the second connection line will cause a larger voltage change, and the difference between the measurement results of the second measurement module in the on state / off state of the second switch module is larger. If the second connection line is not virtually connected, a constant current flowing through the second connection line will cause a smaller voltage change, and the difference between the measurement results of the second measurement module in the on state / off state of the second switch module is smaller. Therefore, the detection efficiency of the virtual connection can be improved.

[0013] In the embodiment of the present application, the first switch module and the second switch module are coupled. The first switch module and the second switch module can be commonly turned on, or commonly turned off, or alternately turned on and turned off. Therefore, the detection efficiency of the virtual connection can be improved.

[0014] In some examples of the first aspect of the embodiment of the present application, the first generation module and the second generation module are the same module. The detection circuit of the fuel cell further includes a switching module. The first generation module is connected with an input terminal of the switching module. A first output terminal of the switching module is connected with the first stack interface. A second output terminal of the switching module is connected with the second stack interface. The switching module is used to control one of the first output terminal and the second output terminal of the switching module to be connected to the input terminal of the switching module.

[0015] In the embodiment of the present application, the first generation module and the second generation module are the same module. Through the switching module, the first generation module and the first resistance module form a loop, or the first generation module and the second resistance module form a loop. On the one hand, the detection cost can be reduced. On the other hand, the detection efficiency of the virtual connection can be improved.

[0016] In some examples of the first aspect of the embodiment of the present application, the switching module is coupled with the first switch module. The first switch module is used to control the on-off between the first resistance module and the reference ground terminal. The switching module is coupled with the second switch module. The second switch module is used to control the on-off between the second resistance module and the reference ground terminal.

[0017] In the embodiment of the present application, the switching module is coupled with the first switch module. The switching module can adjust the state together with the first switch module. The switching module is coupled with the second switch module. The switching module can adjust the state together with the second switch module.

[0018] In some examples of the first aspect of the embodiments of the present application, the third stack interface is connected with the negative electrode of the second battery monomer, the third detection interface is connected with the third stack interface through a third connecting line, and the detection circuit of the fuel cell further includes: a third generation module configured to generate a constant current, an output end of the third generation module being connected with the third stack interface; a third resistance module, a first end of the third detection interface being connected with the third resistance module, and a second end of the third resistance module being connected with a reference ground end; and a third measurement module, a first end of the third measurement module being connected with the third detection interface, and a second end of the third measurement module being connected with the reference ground end, the third measurement module being configured to measure a voltage between the third detection interface and the reference ground end, and a ratio of an allowable connection resistance of the third connecting line to a resistance value of the third resistance module being lower than a measurement resolution of the third measurement module.

[0019] In the embodiments of the present application, the third measurement module can measure the voltage between the third detection interface and the reference ground end, if the third connecting line is not virtually connected, the measurement result of the third measurement module tends to be zero, if the third connecting line is virtually connected, the measurement result of the third measurement module can reflect the voltage change caused by the virtual connection, and the higher the degree of virtual connection is, the greater the voltage change is, in addition, if the reference ground end has a drift, the measurement result of the third measurement module can also reflect the drift.

[0020] In some examples of the first aspect of the embodiments of the present application, the stack further includes a third battery monomer, a negative electrode of the third battery monomer being connected with a positive electrode of the first battery monomer, a fourth stack interface being connected with a positive electrode of the third battery monomer, and a fourth detection interface being connected with the fourth stack interface through a fourth connecting line, and the detection circuit of the fuel cell further includes: a fourth generation module configured to generate a constant current, an output end of the fourth generation module being connected with the fourth stack interface; a fourth resistance module, a first end of the fourth detection interface being connected with the fourth resistance module, and a second end of the fourth resistance module being connected with the reference ground end, a ratio of an allowable voltage deviation of the third battery monomer to a reference voltage of the third battery monomer being a third proportional value, and a ratio of an internal resistance of the third battery monomer to a resistance value of the fourth resistance module being less than the third proportional value; and a fourth measurement module, a first end of the fourth measurement module being connected with the fourth detection interface, and a second end of the fourth measurement module being connected with the first detection interface, the fourth measurement module being configured to measure a voltage between the fourth detection interface and the first detection interface, and a ratio of an allowable connection resistance of the fourth connecting line to the resistance value of the fourth resistance module being lower than a measurement resolution of the fourth measurement module.

[0021] In the embodiment of the present application, when the stack is working, the voltage of the third battery monomer is inspected, the fourth generating module generates a constant current, the fourth measuring module measures the voltage of the third battery monomer, when the fourth connecting line is normally connected, the connection resistance of the fourth connecting line is less than the allowable connection resistance, the voltage change of the constant current flowing through the fourth connecting line is very small and stable, and the measurement result of the fourth measuring module can normally feedback the voltage of the third battery monomer, when the fourth connecting line is virtually connected, the connection resistance of the fourth connecting line increases and is unstable, the constant current flowing through the fourth connecting line will cause a voltage change, since the ratio of the allowable connection resistance of the fourth connecting line to the resistance value of the fourth resistance module is lower than the measurement resolution of the fourth measuring module, and the ratio of the internal resistance of the third battery monomer to the resistance value of the fourth resistance module is less than the first proportion value, therefore, the measurement result of the fourth measuring module can reflect the voltage change caused by the virtual connection.

[0022] In some examples of the first aspect of the embodiment of the present application, the detection circuit of the fuel cell further comprises: a first switch module, the first resistance module is connected to the first end of the first switch module, the second end of the first switch module is connected to the reference ground end, and the first switch module is used for controlling the on-off between the first resistance module and the reference ground end; a second switch module, the second resistance module is connected to the first end of the second switch module, the second end of the second switch module is connected to the reference ground end, and the second switch module is used for controlling the on-off between the second resistance module and the reference ground end; a fourth switch module, the fourth resistance module is connected to the first end of the fourth switch module, the second end of the fourth switch module is connected to the reference ground end, and the fourth switch module is used for controlling the on-off between the fourth resistance module and the reference ground end; the first switch module is coupled with the fourth switch module; the second switch module and the fourth switch module are the same module, and the fourth resistance module is connected to the first end of the second switch module.

[0023] In the embodiment of the present application, when the fourth switch module is in the on state, the fourth resistance module is connected to the ground end, and the fourth generating module and the fourth resistance module form a loop, when the fourth switch module is in the off state, the aforementioned loop is disconnected, if the fourth connecting line is virtually connected, the constant current flowing through the fourth connecting line will cause a larger voltage change, then the difference between the measurement results of the fourth measuring module under the on state / off state of the fourth switch module is larger, if the fourth connecting line is not virtually connected, the constant current flowing through the fourth connecting line will cause a smaller voltage change, then the difference between the measurement results of the fourth measuring module under the on state / off state of the fourth switch module is smaller, and the detection efficiency of the virtual connection can be improved.

[0024] In the embodiment of the present application, the first switch module is coupled with the fourth switch module, the first switch module and the fourth switch module can be commonly turned on, or commonly turned off, or alternately turned on and turned off, and the detection efficiency of the virtual connection can be improved.

[0025] In the embodiment of the present application, the second switch module and the fourth switch module are the same module, the fourth resistance module is connected with the first end of the second switch module, when the second switch module is in the on state, the second resistance module is connected with the ground terminal, and the fourth resistance module is connected with the ground terminal, when the second switch module is in the off state, the second resistance module is disconnected with the ground terminal, and the fourth resistance module is disconnected with the ground terminal, thereby realizing the cooperative control of the connection state of the second resistance module and the fourth resistance module.

[0026] In some examples of the first aspect of the embodiment of the present application, the detection circuit of the fuel cell further comprises: a reference resistance, the resistance value of the reference resistance being smaller than the resistance value of the first resistance module; and a reference switch module, the first end of the reference switch module being connected with the first detection interface, the second end of the reference switch module being connected with the first end of the reference resistance, and the second end of the reference resistance being connected with the second detection interface.

[0027] In the embodiment of the present application, when the first connection line exists a virtual connection, the equivalent resistance of the first connection line changes, when the reference switch module is in the off state, the equivalent resistance between the first detection interface and the second detection interface can be equivalent to the first resistance module, the first measurement module causes the first change due to the virtual connection, when the reference switch module is in the on state, the equivalent resistance between the first detection interface and the second detection interface is the reference resistance, the first measurement module causes the second change due to the virtual connection, since the resistance value of the reference resistance is smaller than the resistance value of the first resistance module, the second change is greater than the first change, accordingly, the measurement precision of the first measurement module on the equivalent resistance of the virtual connection can be improved.

[0028] The second aspect of the embodiment of the present application provides a fuel cell system, comprising: a stack, the first stack interface and the second stack interface being arranged on the stack, wherein the positive electrode of the first cell monomer of the stack is connected with the first stack interface, and the negative electrode of the first cell monomer is connected with the second stack interface; a first detection interface, the first detection interface being connected with the first stack interface through a first connection line; a second detection interface, the second detection interface being connected with the second stack interface through a second connection line; and the detection circuit of the fuel cell as any one of the examples of the first aspect of the embodiment of the present application, wherein the output end of the first generation module of the detection circuit is connected with the first stack interface, the first resistance module of the detection circuit is connected between the first detection interface and the reference ground terminal, and the first measurement module of the detection circuit is connected between the first detection interface and the second detection interface.

[0029] The technical effects of the second aspect of the embodiment of the present application can refer to the first aspect of the embodiment of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1Connection diagram of a fuel cell system of the prior art.

[0031] Figure 2 Connection diagram of a fuel cell system of one of the examples of the present application.

[0032] Figure 3 Connection diagram of a fuel cell system of a second example of the present application.

[0033] Figure 4 Connection diagram of a fuel cell system of a third example of the present application.

[0034] Figure 5 Connection diagram of a fuel cell system of a fourth example of the present application.

[0035] Figure 6 Connection diagram of a fuel cell system of a fifth example of the present application.

[0036] Figure 7 Connection diagram of a fuel cell system of a sixth example of the present application.

[0037] Reference signs:

[0038] 010, stack interface, 020, detection interface, 030, voltage detection module, 040, battery cell to be measured;

[0039] 110, first battery cell, 120, second battery cell, 130, third battery cell, 141, first stack interface, 142, second stack interface, 143, third stack interface, 144, fourth stack interface;

[0040] 210, first current module, 220, second current module, 310, first resistance module, 320, second resistance module, 330, third resistance module, 340, fourth resistance module, 410, first switch module, 420, second switch module, 430, third switch module, 440, fourth switch module, 510, first reference resistance, 520, second reference resistance, 530, third reference resistance, 610, first reference switch module, 620, second reference switch module, 630, third reference switch module, 700, measurement module, 710, first detection interface, 720, second detection interface, 730, third detection interface, 740, fourth detection interface, 750, reference ground terminal, 810, first switching module, 820, second switching module. DETAILED DESCRIPTION

[0041] The terms "first", "second", "third", "fourth", and the like in the description and in the claims of the present application and above-mentioned drawings, if any, are used for distinguishing between similar objects and not necessarily for describing a specific sequential or chronological order. It is to be understood that the use of the terms so construed herein can be interchanged, such that the embodiments of the present application described herein are capable of

[0042] The technical solutions of the embodiments of the present application are described below in conjunction with the accompanying drawings of the present application. The following technical solutions of the embodiments of the present application can be combined in whole or in part without departing from the spirit of the present application, and these combined solutions should be understood as equivalent technical solutions of the embodiments of the present application.

[0043] The number of the battery monomers in the drawings or examples does not constitute a limitation on the number of the battery monomers in the stack. It can be understood that the number of the battery monomers in the stack can be tens or hundreds.

[0044] In some examples of the embodiments of the present application, as Figure 2As shown, the stack includes a first battery cell 110, a first stack interface 141 connected to the positive electrode of the first battery cell 110, a second stack interface 142 connected to the negative electrode of the first battery cell 110, a first detection interface 710 connected to the first stack interface 141 through a first connecting line, and a second detection interface 720 connected to the second stack interface 142 through a second connecting line. In cooperation with the stack, a detection circuit of the fuel cell includes: a first generation module for generating a constant current, an output end of the first generation module being connected to the first stack interface 141; a first resistance module 310, the first detection interface 710 being connected to a first end of the first resistance module 310, a second end of the first resistance module 310 being connected to a reference ground end 750, a ratio of an allowable voltage deviation of the first battery cell 110 to a reference voltage of the first battery cell 110 being a first proportional value, and a ratio of an internal resistance of the first battery cell 110 to a resistance value of the first resistance module 310 being less than the first proportional value; and a first measurement module, a first end of the first measurement module being connected to the first detection interface 710, and a second end of the first measurement module being connected to the second detection interface 720, the first measurement module being used for measuring a voltage between the first detection interface 710 and the second detection interface 720, and a ratio of an allowable connecting resistance of the first connecting line to the resistance value of the first resistance module 310 being lower than a measurement resolution of the first measurement module.

[0045] As shown in the example, Figure 2 The fuel cell system includes a stack and a detection circuit.

[0046] The stack includes a first battery cell 110, a second battery cell 120, and a third battery cell 130, wherein the positive electrode of the stack is connected in series with the positive electrode of the third battery cell 130, the third battery cell 130 is arranged adjacent to the first battery cell 110, and the negative electrode of the third battery cell 130 is connected in series with the positive electrode of the first battery cell 110, the second battery cell 120 is arranged adjacent to the first battery cell 110, and the negative electrode of the first battery cell 110 is connected in series with the positive electrode of the second battery cell 120, and the negative electrode of the second battery cell 120 is connected in series with the negative electrode of the stack; the stack is provided with a first stack interface 141 and a second stack interface 142, wherein the first stack interface 141 is connected to the positive electrode of the first battery cell 110, and the second stack interface 142 is connected to the negative electrode of the first battery cell 110.

[0047] The detection circuit comprises a first current module 210, a first resistance module 310, a measurement module 700, a first detection interface 710 and a second detection interface 720. The first detection interface 710 is connected to the first battery stack interface 141 through a first connecting line, and the second detection interface 720 is connected to the second battery stack interface 142 through a second connecting line. The first current module 210 is equivalent to the first generation module described above. The first current module 210 is a constant current source. When the first current module 210 is started, the first current module 210 can apply a constant current to the first battery stack interface 141. The first end of the first resistance module 310 is connected to the first detection interface 710, and the second end of the first resistance module 310 is connected to a reference ground end 750. The measurement module 700 can be equivalent to the first measurement module described above. The measurement module 700 comprises at least one voltage measurement circuit. The first end of the measurement module 700 is connected to the first detection interface 710, and the second end of the measurement module 700 is connected to the second detection interface 720. The measurement module 700 can measure the voltage between the first detection interface 710 and the second detection interface 720.

[0048] The first resistance module 310 in the detection circuit is associated with the first battery monomer 110 in the battery stack. Specifically, the reference voltage can be the rated voltage of the first battery monomer 110. The difference between the actual voltage of the first battery monomer 110 and the rated voltage is the actual voltage deviation. The allowable voltage deviation can be determined according to the characteristics of the battery stack, the actual needs of the application scenario, relevant standards or protocols, etc. When the first battery monomer 110 is in a normal working state, the actual voltage deviation of the first battery monomer 110 is less than or equal to the allowable voltage deviation. If the actual voltage deviation of the first battery monomer 110 is greater than the allowable voltage deviation, the first battery monomer 110 can be in a fault state. The ratio of the allowable voltage deviation of the first battery monomer 110 to the reference voltage of the first battery monomer 110 is a first proportion value. The ratio of the internal resistance of the first battery monomer 110 to the resistance value of the first resistance module 310 is less than the first proportion value.

[0049] The first measurement module in the detection circuit has an association relationship with the first connection line. Specifically, the equivalent connection resistance of the first connection line includes the resistance between the first connection line and the first battery interface 141, the self-resistance of the first connection line, and the resistance between the first connection line and the first detection interface 710. The allowable connection resistance can be determined according to the actual requirements of the application scenario, relevant standards or protocols, etc. When there is no virtual connection between the first connection line and the first battery interface 141, and there is no virtual connection between the first connection line and the first battery interface 141, the equivalent connection resistance of the first connection line is less than or equal to the allowable connection resistance. If the connection between the first connection line and the first battery interface 141 has a virtual connection, the equivalent resistance between the first connection line and the first battery interface 141 increases, and the equivalent connection resistance of the first connection line is greater than the allowable connection resistance. If the connection between the first connection line and the first detection interface 710 has a virtual connection, the equivalent resistance between the first connection line and the first detection interface 710 increases, and the equivalent connection resistance of the first connection line is greater than the allowable connection resistance. The ratio of the allowable connection resistance of the first connection line to the resistance value of the first resistance module 310 is lower than the measurement resolution of the first measurement module.

[0050] In some cases, during the operation of the fuel cell system, the electrochemical reaction in the first cell 110 generates an output voltage, for example, the rated output voltage of the first cell 110 can be 0.5 V, the first current module 210 is activated to generate a constant current, for example, the first current module 210 can continuously output a constant current of 1 mA, the equivalent connection resistance of the first connection line approaches zero, for example, 0.1 Ω, the constant current of the first current module 210 flowing through the first connection line hardly generates additional voltage drop, the measurement module 700 measures the voltage between the first detection interface 710 and the second detection interface 720, the ratio of the allowable voltage deviation of the first cell 110 to the reference voltage of the first cell 110 is a first proportion value, the ratio of the internal resistance of the first cell 110 to the resistance value of the first resistance module 310 is less than the first proportion value, for example, the resistance value of the first resistance module 310 can be 1 MΩ, the difference between the voltage of the first resistance module 310 and the actual voltage of the first cell 110 is less than the allowable voltage deviation of the first cell 110, and the difference between the measurement result of the measurement module 700 and the actual voltage of the first cell 110 is less than the allowable voltage deviation of the first cell 110; subsequently, when the virtual connection occurs between the first connection line and the first stack interface 141, the equivalent connection resistance of the first connection line is greater than the allowable connection resistance, for example, the equivalent connection resistance of the first connection line can reach 500 Ω, when the constant current of the first current module 210 flows through the first connection line, additional voltage drop is generated, for example, 0.5 V, further, even if the equivalent connection resistance of the first connection line is not the value of the foregoing example, since the ratio of the allowable connection resistance of the first connection line to the resistance value of the first resistance module 310 is lower than the measurement resolution of the first measurement module, when the equivalent connection resistance of the first connection line is greater than the allowable connection resistance thereof, that is, the virtual connection of the first connection line occurs, the additional voltage drop caused thereby is also within the measurement resolution of the measurement module 700, so as to be recognized by the measurement module 700, according to the change of the measurement result of the measurement module 700 before and after the virtual connection, it can be determined that the virtual connection of the first connection line occurs.

[0051] In some examples of the embodiments of the present application, as Figure 3As shown, the stack further comprises a second battery cell 120, the negative electrode of the first battery cell 110 is connected with the positive electrode of the second battery cell 120, and the third detection interface 730 is connected with the negative electrode of the second battery cell 120. In cooperation with the foregoing stack, the detection circuit of the fuel cell further comprises: a second generation module for generating a constant current, the output end of the second generation module is connected with the second stack interface 142; a second resistance module 320, the second detection interface 720 is connected with the first end of the second resistance module 320, the second end of the second resistance module 320 is connected with the reference ground end 750, the ratio of the allowable voltage deviation of the second battery cell 120 to the reference voltage of the second battery cell 120 is a second proportional value, and the ratio of the internal resistance of the second battery cell 120 to the resistance value of the second resistance module 320 is less than the second proportional value; and a second measurement module, the first end of the second measurement module is connected with the second detection interface 720, the second end of the second measurement module is connected with the third detection interface 730, the second measurement module is used for measuring the voltage between the second detection interface 720 and the third detection interface 730, and the ratio of the allowable connection resistance of the second connection line to the resistance value of the second resistance module 320 is lower than the measurement resolution of the second measurement module.

[0052] Exemplarily, as Figure 3 As shown, the fuel cell system comprises a stack and a detection circuit.

[0053] The stack comprises a first battery cell 110, a second battery cell 120 and a third battery cell 130, wherein the positive electrode of the stack is connected in series with the positive electrode of the third battery cell 130, the third battery cell 130 is arranged adjacent to the first battery cell 110, and the negative electrode of the third battery cell 130 is connected in series with the positive electrode of the first battery cell 110, the second battery cell 120 is arranged adjacent to the first battery cell 110, and the negative electrode of the second battery cell 120 is connected in series with the positive electrode of the first battery cell 110, the negative electrode of the second battery cell 120 is connected in series with the negative electrode of the stack; the first stack interface 141, the second stack interface 142, the third stack interface 143 and the fourth stack interface 144 are arranged on the stack, wherein the first stack interface 141 is connected with the positive electrode of the first battery cell 110, the second stack interface 142 is connected with the negative electrode of the first battery cell 110, the third stack interface 143 is connected with the negative electrode of the second battery cell 120, and the fourth stack interface 144 is connected with the positive electrode of the third battery cell 130.

[0054] The detection circuit comprises a first current module 210, a first switching module 810, a first resistance module 310, a second resistance module 320, a third resistance module 330, a fourth resistance module 340, a measurement module 700, a first detection interface 710, a second detection interface 720, a third detection interface 730 and a fourth detection interface 740. The first detection interface 710 is connected to the first battery interface 141 through a first connecting line. The second detection interface 720 is connected to the second battery interface 142 through a second connecting line. The third detection interface 730 is connected to the third battery interface 143 through a third connecting line. The fourth detection interface 740 is connected to the fourth battery interface 144 through a fourth connecting line. The first end of the first resistance module 310 is connected to the first detection interface 710. The second end of the first resistance module 310 is connected to a reference ground end 750. The first end of the second resistance module 320 is connected to the second detection interface 720. The second end of the second resistance module 320 is connected to the reference ground end 750. The first end of the third resistance module 330 is connected to the second detection interface 720. The second end of the third resistance module 330 is connected to the reference ground end 750. The first end of the fourth resistance module 340 is connected to the second detection interface 720. The second end of the fourth resistance module 340 is connected to the reference ground end 750.

[0055] The first current module 210 corresponds to the first generation module and the second generation module described above. The first current module 210 is a constant current source. The output end of the first current module 210 is connected to the input end of the first switching module 810. The first output end of the first switching module 810 is connected to the first battery interface 141. The second output end of the first switching module 810 is connected to the second battery interface 142. The third output end of the first switching module 810 is connected to the third battery interface 143. The fourth output end of the first switching module 810 is connected to the fourth battery interface 144. When the first current module 210 is started, the first current module 210 can provide a constant current to the first switching module 810. Through the switching of the first switching module 810, the first current module 210 can provide a constant current to one of the first battery interface 141, the second battery interface 142, the third battery interface 143 and the fourth battery interface 144.

[0056] The measurement module 700 can be equivalent to the first measurement module and the second measurement module described above. The measurement module 700 includes at least one voltage measurement circuit, preferably at least four voltage measurement circuits. The first end of the measurement module 700 is connected to the first detection interface 710. The second end of the measurement module 700 is connected to the second detection interface 720. The measurement module 700 can measure the voltage between the first detection interface 710 and the second detection interface 720. The third end of the measurement module 700 is connected to the third detection interface 730. The measurement module 700 can measure the voltage between the second detection interface 720 and the third detection interface 730. The ground end of the measurement module 700 is connected to the reference ground end 750. The measurement module can measure the voltage between the third detection interface 730 and the reference ground end 750. The fourth end of the measurement module 700 is connected to the fourth detection interface 740. The measurement module 700 can measure the voltage between the fourth detection interface 740 and the first detection interface 710.

[0057] The first resistance module 310 in the detection circuit is associated with the first battery monomer 110 in the stack. Specifically, the ratio of the allowable voltage deviation of the first battery monomer 110 to the reference voltage of the first battery monomer 110 is a first proportion value, and the ratio of the internal resistance of the first battery monomer 110 to the resistance value of the first resistance module 310 is less than the first proportion value. The second resistance module 320 in the detection circuit is associated with the second battery monomer 120 in the stack. Specifically, the ratio of the allowable voltage deviation of the second battery monomer 120 to the reference voltage of the second battery monomer 120 is a second proportion value, and the ratio of the internal resistance of the second battery monomer 120 to the resistance value of the second resistance module 320 is less than the second proportion value. The fourth resistance module 340 in the detection circuit is associated with the third battery monomer 130 in the stack. The ratio of the allowable voltage deviation of the third battery monomer 130 to the reference voltage of the third battery monomer 130 is a third proportion value, and the ratio of the internal resistance of the third battery monomer 130 to the resistance value of the fourth resistance module 340 is less than the third proportion value. It can be understood that considering the consistency of each battery monomer in the stack, the first resistance module 310, the second resistance module 320, the third resistance module 330, and the fourth resistance module 340 can have the same resistance value.

[0058] The measurement module 700 in the detection circuit has a correlation relationship with the first connection line. Specifically, the ratio of the allowable connection resistance of the first connection line to the resistance value of the first resistance module 310 is lower than the measurement resolution of the measurement module 700. The measurement module 700 in the detection circuit has a correlation relationship with the second connection line. Specifically, the ratio of the allowable connection resistance of the second connection line to the resistance value of the second resistance module 320 is lower than the measurement resolution of the measurement module 700. It can be understood that, considering that the first resistance module 310, the second resistance module 320, the third resistance module 330 and the fourth resistance module 340 can have the same resistance value, the first connection line, the second connection line, the third connection line and the fourth connection line can adopt the same line body and connection mode, and each measurement port of the measurement module 700 can have the same measurement resolution.

[0059] In some examples of the embodiments of the present application, as shown in Figure 3 The detection circuit of the fuel cell further includes a switching module. The first generation module is connected to the input end of the switching module. The first output end of the switching module is connected to the first stack interface 141. The second output end of the switching module is connected to the second stack interface 142. The switching module is used to control one of the first output end and the second output end of the switching module to be connected to the input end of the switching module.

[0060] For example, in combination with the foregoing Figure 3 As shown in The detection circuit can include a first current module 210. The first generation module and the second generation module are both implemented by the first current module 210. The output end of the first current module 210 is connected to the input end of the first switching module 810. The first output end of the first switching module 810 is connected to the first stack interface 141. The second output end of the first switching module 810 is connected to the second stack interface 142. When the switching module is switched to the first switching state, the output end of the first current module 210 is connected to the first output end of the first switching module 810. The first current module 210 provides a constant current to and only to the first stack interface 141. When the switching module is switched to the second switching state, the output end of the first current module 210 is connected to the second output end of the first switching module 810. The first current module 210 provides a constant current to and only to the second stack interface 142.

[0061] In some examples of the embodiments of the present application, as shown in Figure 3As shown, the foregoing stack further comprises a third stack interface 143 connected with the negative electrode of the second battery cell 120, and a third detection interface 730 connected with the third stack interface 143 through a third connecting line. In cooperation with the foregoing stack, the detection circuit of the fuel cell further comprises: a third generation module for generating a constant current, an output terminal of the third generation module being connected with the third stack interface 143; a third resistance module 330, the third detection interface 730 being connected with a first terminal of the third resistance module 330, and a second terminal of the third resistance module 330 being connected with a reference ground terminal 750; and a third measurement module, a first terminal of the third measurement module being connected with the third detection interface 730, and a second terminal of the third measurement module being connected with the reference ground terminal 750, the third measurement module being used for measuring the voltage between the third detection interface 730 and the reference ground terminal 750, and the ratio of the allowable connection resistance of the third connecting line to the resistance value of the third resistance module 330 being lower than the measurement resolution of the third measurement module.

[0062] Exemplarily, in cooperation with the foregoing Figure 3As shown, the first current module 210 can also correspond to the third generating module as described above. The first current module 210 is a constant current source, the output terminal of the first current module 210 is connected with the input terminal of the first switching module 810, the third output terminal of the first switching module 810 is connected with the third battery interface 143, when the switching module is switched to the third switching state, the output terminal of the first current module 210 is connected with the third output terminal of the first switching module 810, the first current module 210 provides constant current to the third battery interface 143 only. Correspondingly, the third battery interface 143, the third connecting line, the third detection interface 730, the third resistance module 330 and the reference ground terminal 750 form a series circuit, the measurement module 700 can also correspond to the third measurement module as described above, the measurement module 700 measures the voltage between the third detection interface 730 and the reference ground terminal 750, further, the ratio of the allowable connection resistance of the third connecting line and the resistance of the third resistance module 330 is lower than the measurement resolution of the third measurement module, the third battery interface 143 is connected with the reference ground terminal 750, the third detection interface 730 is connected with the reference ground terminal 750 through the third resistance module 330, when the third connecting line is not virtually connected, the connection resistance of the third connecting line is very small, the voltage drop between the third battery interface 143 and the third detection interface 730 tends to be zero, therefore, the voltage measurement result between the third detection interface 730 and the reference ground terminal 750 also tends to be zero, when the third connecting line is virtually connected, the connection resistance of the third connecting line increases, the voltage drop between the third battery interface 143 and the third detection interface 730 increases, therefore, the voltage measurement result between the third detection interface 730 and the reference ground terminal 750 also increases, so that the virtual connection of the third connecting line can be determined according to the voltage measurement result of the measurement module 700.

[0063] In some examples of the embodiments of the present application, as shown in FIG. 7, the first current module 210 can also correspond to the third generating module as described above. The first current module 210 is a constant current source, the output terminal of the first current module 210 is connected with the input terminal of the first switching module 810, the third output terminal of the first switching module 810 is connected with the third battery interface 143, when the switching module is switched to the third switching state, the output terminal of the first current module 210 is connected with the third output terminal of the first switching module 810, the first current module 210 provides constant current to the third battery interface 143 only. Correspondingly, the third battery interface 143, the third connecting line, the third detection interface 730, the third resistance module 330 and the reference ground terminal 750 form a series circuit, the measurement module 700 can also correspond to the third measurement module as described above, the measurement module 700 measures the voltage between the third detection interface 730 and the reference ground terminal 750, further, the ratio of the allowable connection resistance of the third connecting line and the resistance of the third resistance module 330 is lower than the measurement resolution of the third measurement module, the third battery interface 143 is connected with the reference ground terminal 750, the third detection interface 730 is connected with the reference ground terminal 750 through the third resistance module 330, when the third connecting line is not virtually connected, the connection resistance of the third connecting line is very small, the voltage drop between the third battery interface 143 and the third detection interface 730 tends to be zero, therefore, the voltage measurement result between the third detection interface 730 and the reference ground terminal 750 also tends to be zero, when the third connecting line is virtually connected, the connection resistance of the third connecting line increases, the voltage drop between the third battery interface 143 and the third detection interface 730 increases, therefore, the voltage measurement result between the third detection interface 730 and the reference ground terminal 750 also increases, so that the virtual connection of the third connecting line can be determined according to the voltage measurement result of the measurement module 700. Figure 3As shown, the battery stack further includes a third battery cell 130, a negative electrode of the third battery cell 130 is connected with a positive electrode of the first battery cell 110, a fourth battery stack interface 144 is connected with a positive electrode of the third battery cell 130, the fourth detection interface 740 is connected with the fourth battery stack interface 144 through a fourth connecting line, and the detection circuit further includes: a fourth generation module for generating a constant current, an output end of the fourth generation module is connected with the fourth battery stack interface 144; a fourth resistance module 340, the fourth detection interface 740 is connected with a first end of the fourth resistance module 340, a second end of the fourth resistance module 340 is connected with the reference ground end 750, a ratio of an allowable voltage deviation of the third battery cell 130 to a reference voltage of the third battery cell 130 is a third proportional value, and a ratio of an internal resistance of the third battery cell 130 to a resistance value of the fourth resistance module 340 is less than the third proportional value; and a fourth measurement module, a first end of the fourth measurement module is connected with the fourth detection interface 740, and a second end of the fourth measurement module is connected with the first detection interface 710, and the fourth measurement module is configured to measure a voltage between the fourth detection interface 740 and the first detection interface 710, and a ratio of an allowable connection resistance of the fourth connecting line to the resistance value of the fourth resistance module 340 is lower than a measurement resolution of the fourth measurement module.

[0064] Exemplarily, in combination with the foregoing Figure 3 As shown, the first current module 210 can also correspond to the fourth generation module described in the foregoing embodiments of the present application, an output end of the first current module 210 is connected with an input end of the first switching module 810, a fourth output end of the first switching module 810 is connected with the fourth battery stack interface 144, when the switching module is switched to the fourth switching state, the output end of the first current module 210 is connected with the fourth output end of the first switching module 810, and the first current module 210 provides a constant current to and only to the fourth battery stack interface 144, corresponding thereto, the fourth battery stack interface 144, the fourth connecting line, the fourth detection interface 740, the fourth resistance module 340 and the reference ground end 750 form a series circuit, the measurement module 700 can also correspond to the fourth measurement module described in the foregoing embodiments of the present application, and the measurement module 700 measures a voltage between the fourth detection interface 740 and the first detection interface 710, further, a ratio of an allowable voltage deviation of the third battery cell 130 to a reference voltage of the third battery cell 130 is a third proportional value, a ratio of an internal resistance of the third battery cell 130 to a resistance value of the fourth resistance module 340 is less than the third proportional value, and a ratio of an allowable connection resistance of the fourth connecting line to the resistance value of the fourth resistance module 340 is lower than a measurement resolution of the measurement module 700, and according to a measurement result of the measurement module 700, whether the fourth connecting line is virtually connected can be measured.

[0065] In some examples of the embodiments of the present application, as Figure 4 In combination with Figure 5As shown, the detection circuit of the fuel cell, in cooperation with the foregoing stack, further comprises: a first switch module 410, the first resistance module 310 is connected with a first end of the first switch module 410, a second end of the first switch module 410 is connected with a reference ground end 750, and the first switch module 410 is used for controlling the on-off between the first resistance module 310 and the reference ground end 750.

[0066] In some examples of the embodiments of the present application, as shown in Figure 4 The detection circuit of the fuel cell further comprises: a second switch module 420, the second resistance module 320 is connected with a first end of the second switch module 420, a second end of the second switch module 420 is connected with the reference ground end 750, and the second switch module 420 is used for controlling the on-off between the second resistance module 320 and the reference ground end 750.

[0067] Exemplarily, as shown in Figure 4 The fuel cell system comprises a stack and a detection circuit, wherein the stack can be arranged as described in the foregoing examples of the description, and details are not described herein. Figure 3 The fuel cell system comprises a stack and a detection circuit, wherein the stack can be arranged as described in the foregoing examples of the description, and details are not described herein.

[0068] The detection circuit comprises a first current module 210, a first switching module 810, a first resistance module 310, a second resistance module 320, a third resistance module 330, a fourth resistance module 340, a first switch module 410, a second switch module 420, a third switch module 430, a fourth switch module 440, a measurement module 700, a first detection interface 710, a second detection interface 720, a third detection interface 730, and a fourth detection interface 740. The first detection interface 710 is connected to the first electrode interface 141 through a first connecting line. The second detection interface 720 is connected to the second electrode interface 142 through a second connecting line. The third detection interface 730 is connected to the third electrode interface 143 through a third connecting line. The fourth detection interface 740 is connected to the fourth electrode interface 144 through a fourth connecting line. The first end of the first resistance module 310 is connected to the first detection interface 710. The second end of the first resistance module 310 is connected to the first end of the first switch module 410. The second end of the first switch module 410 is connected to a reference ground end 750. The first end of the second resistance module 320 is connected to the second detection interface 720. The second end of the second resistance module 320 is connected to the first end of the second switch module 420. The second end of the second switch module 420 is connected to the reference ground end 750. The first end of the third resistance module 330 is connected to the third detection interface 730. The second end of the third resistance module 330 is connected to the first end of the third switch module 430. The second end of the third switch module 430 is connected to the reference ground end 750. The first end of the fourth resistance module 340 is connected to the fourth detection interface 740. The second end of the fourth resistance module 340 is connected to the first end of the fourth switch module 440. The second end of the fourth switch module 440 is connected to the reference ground end 750.

[0069] The first current module 210 can be equivalent to the first generation module, the second generation module, the third generation module, and the fourth generation module described above. The first current module 210 is a constant current source. The output end of the first current module 210 is connected to the input end of the first switching module 810. The first output end of the first switching module 810 is connected to the first electrode interface 141. The second output end of the first switching module 810 is connected to the second electrode interface 142. The third output end of the first switching module 810 is connected to the third electrode interface 143. The fourth output end of the first switching module 810 is connected to the fourth electrode interface 144. When the first current module 210 is started, the first switching module 810 is switched to connect. The first current module 210 can provide a constant current to one of the first electrode interface 141, the second electrode interface 142, the third electrode interface 143, and the fourth electrode interface 144.

[0070] The measurement module 700 can be equivalent to the first measurement module, second measurement module, third measurement module, and fourth measurement module described in the embodiments of this application. The measurement module 700 includes at least one voltage measurement circuit; preferably, it includes at least four voltage measurement circuits. A first end of the measurement module 700 is connected to a first detection interface 710, and a second end is connected to a second detection interface 720. The measurement module 700 can measure the voltage between the first detection interface 710 and the second detection interface 720. The third terminal of the measurement module 700 is connected to the third detection interface 730, and the measurement module 700 can measure the voltage between the second detection interface 720 and the third detection interface 730. The ground terminal of the measurement module 700 is connected to the reference ground terminal 750, and the measurement module can measure the voltage between the third detection interface 730 and the reference ground terminal 750. The fourth terminal of the measurement module 700 is connected to the fourth detection interface 740, and the measurement module 700 can measure the voltage between the fourth detection interface 740 and the first detection interface 710.

[0071] For example, such as Figure 5 As shown, the fuel cell system includes a fuel cell stack and a detection circuit. The configuration of the fuel cell stack can be referred to the aforementioned... Figure 3 The example description will not be repeated here.

[0072] The detection circuit can include the first current module 210, the first switching module 810, the second current module 220, the second switching module 820, the first resistance module 310, the second resistance module 320, the third resistance module 330, the fourth resistance module 340, the first switch module 410, the second switch module 420, the measurement module 700, the first detection interface 710, the second detection interface 720, the third detection interface 730, and the fourth detection interface 740. The first detection interface 710 is connected to the first electrode interface 141 through a first connecting line. The second detection interface 720 is connected to the second electrode interface 142 through a second connecting line. The third detection interface 730 is connected to the third electrode interface 143 through a third connecting line. The fourth detection interface 740 is connected to the fourth electrode interface 144 through a fourth connecting line. The first end of the first resistance module 310 is connected to the first detection interface 710. The first end of the first resistance module 310 is connected to the first detection interface 710. The second end of the first resistance module 310 is connected to the first end of the first switch module 410. The second end of the first switch module 410 is connected to a reference ground end 750. The first end of the second resistance module 320 is connected to the second detection interface 720. The second end of the second resistance module 320 is connected to the first end of the second switch module 420. The second end of the second switch module 420 is connected to the reference ground end 750. The first end of the third resistance module 330 is connected to the third detection interface 730. In this example, the first switch module 410 can be equivalent to the third switch module 430 in the foregoing example. The second end of the third resistance module 330 is connected to the first end of the first switch module 410. The first end of the fourth resistance module 340 is connected to the fourth detection interface 740. In this example, the second switch module 420 can be equivalent to the fourth switch module 440 in the foregoing example. The second end of the fourth resistance module 340 is connected to the first end of the second switch module 420.

[0073] In this embodiment, the first current module 210 can be equivalent to the first generating module and the fourth generating module mentioned above in the present application embodiments, and the second current module 220 can be equivalent to the second generating module and the third generating module mentioned above in the present application embodiments. The first current module 210 is a constant current source, and its output terminal is connected to the input terminal of the first switching module 810. The first output terminal of the first switching module 810 is connected to the first fuel cell interface 141, and its second output terminal is connected to the fourth fuel cell interface 144. The second current module 220 is a constant current source, and its output terminal is connected to the second switching module 810. The input terminal of the second switching module 820 is connected to the input terminal of the second switching module 820. The first output terminal of the second switching module 820 is connected to the second fuel cell interface 142, and the second output terminal of the second switching module 820 is connected to the third fuel cell interface 143. When the first current module 210 is started, the first switching module 810 can switch the connection and provide a constant current to the first fuel cell interface 141 or the fourth fuel cell interface 144. When the second current module 220 is started, the second switching module 820 can switch the connection and provide a constant current to the second fuel cell interface 142 or the third fuel cell interface 143.

[0074] For example, such as Figure 6 As shown, the fuel cell system includes a fuel cell stack and a detection circuit. The configuration of the fuel cell stack can be referred to the aforementioned... Figure 3 The example description will not be repeated here.

[0075] This example can be found in Figure 5 Further improvements to the example: Specifically, this example also includes the following: the control terminal of the first switching module 810 is coupled to the measurement module 700; the control terminal of the second switching module 820 is coupled to the measurement module 700; the control terminal of the first switch module 410 is coupled to the measurement module 700; and the control terminal of the second switch module 420 is coupled to the measurement module 700.

[0076] In some examples of embodiments of this application, such as Figure 6As shown, the first switch module 410, the first resistance module 310 is connected with the first end of the first switch module 410, the second end of the first switch module 410 is connected with the reference ground terminal 750, and the first switch module 410 is used for controlling the on-off between the first resistance module 310 and the reference ground terminal 750; the second switch module 420, the second resistance module 320 is connected with the first end of the second switch module 420, the second end of the second switch module 420 is connected with the reference ground terminal 750, and the second switch module 420 is used for controlling the on-off between the second resistance module 320 and the reference ground terminal 750; the fourth switch module 440, the fourth resistance module 340 is connected with the first end of the fourth switch module 440, the second end of the fourth switch module 440 is connected with the reference ground terminal 750, and the fourth switch module 440 is used for controlling the on-off between the fourth resistance module 340 and the reference ground terminal 750; the first switch module 410 is coupled with the fourth switch module 440; the second switch module 420 and the fourth switch module 440 are the same module, and the fourth resistance module 340 is connected with the first end of the second switch module 420.

[0077] In some examples of the embodiments of the present application, as shown in Figure 7 As shown, the detection circuit further comprises: a reference resistance, the resistance value of the reference resistance is less than the resistance value of the first resistance module 310; a reference switch module, the first end of the reference switch module is connected with the first detection interface 710, the second end of the reference switch module is connected with the first end of the reference resistance, and the second end of the reference resistance is connected with the second detection interface 720.

[0078] Exemplarily, as shown in Figure 7 The fuel cell system comprises a stack and a detection circuit, wherein the stack can be arranged as described in the foregoing Figure 3 Examples, which will not be described herein.

[0079] The detection circuit comprises a first current module 210, a first switching module 810, a first resistance module 310, a second resistance module 320, a third resistance module 330, a fourth resistance module 340, a first switching module 410, a second switching module 420, a third switching module 430, a fourth switching module 440, a first reference resistance 510, a second reference resistance 520, a third reference resistance 530, a first reference switching module 610, a second reference switching module 620, a third reference switching module 630, a measurement module 700, a first detection interface 710, a second detection interface 720, a third detection interface 730 and a fourth detection interface 740. The first detection interface 710 is connected with the first electrode interface 141 through a first connecting line, the second detection interface 720 is connected with the second electrode interface 142 through a second connecting line, the third detection interface 730 is connected with the third electrode interface 143 through a third connecting line, and the fourth detection interface 740 is connected with the fourth electrode interface 144 through a fourth connecting line. The first end of the first switching module 410 is connected with the first detection interface 710, the second end of the first switching module 410 is connected with the first end of the first resistance module 310, the second end of the first resistance module 310 is connected with a reference ground end 750, the first end of the second switching module 420 is connected with the second detection interface 720, the second end of the second switching module 420 is connected with the first end of the second resistance module 320, the second end of the second resistance module 320 is connected with the reference ground end 750, the first end of the first reference switching module 610 is connected with the first detection interface 710, the second end of the first reference switching module 610 is connected with the first end of the first reference resistance 510, the second end of the first reference resistance 510 is connected with the second detection interface 720, the first end of the third switching module 430 is connected with the third detection interface 730, the second end of the third switching module 430 is connected with the first end of the third resistance module 330, the second end of the third resistance module 330 is connected with the reference ground end 750, the first end of the second reference switching module 620 is connected with the second detection interface 720, the second end of the second reference switching module 620 is connected with the first end of the second reference resistance 520, the second end of the second reference resistance 520 is connected with the second detection interface 720, the first end of the fourth switching module 440 is connected with the fourth detection interface 740, the second end of the fourth switching module 440 is connected with the first end of the fourth resistance module 340, the second end of the fourth resistance module 340 is connected with the reference ground end 750, the first end of the third reference switching module 630 is connected with the fourth detection interface 740, the second end of the third reference switching module 630 is connected with the first end of the third reference resistance 530, and the second end of the third reference resistance 530 is connected with the first detection interface 710.

[0080] The first current module 210 can be equivalent to the first generating module, the second generating module, the third generating module and the fourth generating module as mentioned above. The first current module 210 is a constant current source. The output end of the first current module 210 is connected with the input end of the first switching module 810. The first output end of the first switching module 810 is connected with the first battery interface 141. The second output end of the first switching module 810 is connected with the second battery interface 142. The third output end of the first switching module 810 is connected with the third battery interface 143. The fourth output end of the first switching module 810 is connected with the fourth battery interface 144. When the first current module 210 is started, the first switching module 810 is switched to connect. The first current module 210 can provide a constant current to one of the first battery interface 141, the second battery interface 142, the third battery interface 143 and the fourth battery interface 144.

[0081] The measurement module 700 can be equivalent to the first measurement module, the second measurement module, the third measurement module and the fourth measurement module as mentioned above. The measurement module 700 includes at least one voltage measurement circuit. Preferably, the measurement module 700 includes at least four voltage measurement circuits. The first end of the measurement module 700 is connected with the first detection interface 710. The second end of the measurement module 700 is connected with the second detection interface 720. The measurement module 700 can measure the voltage between the first detection interface 710 and the second detection interface 720. The third end of the measurement module 700 is connected with the third detection interface 730. The measurement module 700 can measure the voltage between the second detection interface 720 and the third detection interface 730. The ground end of the measurement module 700 is connected with the reference ground end 750. The measurement module can measure the voltage between the third detection interface 730 and the reference ground end 750. The fourth end of the measurement module 700 is connected with the fourth detection interface 740. The measurement module 700 can measure the voltage between the fourth detection interface 740 and the first detection interface 710.

[0082] The application also provides a fuel cell system, which includes the fuel cell stack system as mentioned above. Figures 2 to 7As shown, the fuel cell system comprises: an electric pile, a first electric pile interface 141 and a second electric pile interface 142 are arranged on the electric pile, wherein a positive electrode of a first cell 110 of the electric pile is connected with the first electric pile interface 141, and a negative electrode of the first cell 110 is connected with the second electric pile interface 142; a first detection interface 710, the first detection interface 710 is connected with the first electric pile interface 141 through a first connecting line; a second detection interface 720, the second detection interface 720 is connected with the second electric pile interface 142 through a second connecting line; and the detection circuit as any one of the foregoing examples of the embodiments of the present application, wherein an output end of the first generating module of the detection circuit is connected with the first electric pile interface 141, the first resistance module 310 of the detection circuit is connected between the first detection interface 710 and a reference ground end 750, and the first measuring module of the detection circuit is connected between the first detection interface 710 and the second detection interface 720.

[0083] The above embodiments are only used to illustrate the technical solutions of the present application, but not limit the same; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that the technical solutions recorded in the foregoing embodiments can still be modified, or some technical features can be replaced by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A detection circuit of a fuel cell, an electric pile including a first cell, a first pile interface connected to a positive electrode of the first cell, a second pile interface connected to a negative electrode of the first cell, a first detection interface connected to the first pile interface through a first connection line, and a second detection interface connected to the second pile interface through a second connection line, characterized in that, The detection circuit comprises: A first generating module for generating a constant current, an output end of the first generating module being connected with the first stack interface; A first resistance module, the first detection interface being connected with a first end of the first resistance module, a second end of the first resistance module being connected with a reference ground end, a ratio of an allowable voltage deviation of the first battery cell to a reference voltage of the first battery cell being a first proportion value, a ratio of an internal resistance of the first battery cell to a resistance value of the first resistance module being less than the first proportion value; A first measuring module, a first end of the first measuring module being connected with the first detection interface, a second end of the first measuring module being connected with the second detection interface, the first measuring module being used for measuring a voltage between the first detection interface and the second detection interface, a ratio of an allowable connection resistance of the first connection line to the resistance value of the first resistance module being lower than a measurement resolution of the first measuring module.

2. The detection circuit of claim 1, wherein, The stack further comprises a second battery cell, a negative electrode of the first battery cell being connected with a positive electrode of the second battery cell, a third detection interface being connected with a negative electrode of the second battery cell, the detection circuit further comprising: A second generating module for generating a constant current, an output end of the second generating module being connected with the second stack interface; A second resistance module, the second detection interface being connected with a first end of the second resistance module, a second end of the second resistance module being connected with the reference ground end, a ratio of an allowable voltage deviation of the second battery cell to a reference voltage of the second battery cell being a second proportion value, a ratio of an internal resistance of the second battery cell to a resistance value of the second resistance module being less than the second proportion value; A second measuring module, a first end of the second measuring module being connected with the second detection interface, a second end of the second measuring module being connected with the third detection interface, the second measuring module being used for measuring a voltage between the second detection interface and the third detection interface, a ratio of an allowable connection resistance of the second connection line to the resistance value of the second resistance module being lower than a measurement resolution of the second measuring module.

3. The detection circuit of claim 2, wherein, Further comprising: A first switch module, the first resistance module being connected with a first end of the first switch module, a second end of the first switch module being connected with the reference ground end, the first switch module being used for controlling on-off between the first resistance module and the reference ground end; A second switch module, the second resistance module being connected with a first end of the second switch module, a second end of the second switch module being connected with the reference ground end, the second switch module being used for controlling on-off between the second resistance module and the reference ground end; The first switch module and the second switch module are coupled.

4. The detection circuit of claim 2, wherein, The first generating module and the second generating module are the same module, the detection circuit further comprising: A switching module, the first generating module is connected with an input end of the switching module, a first output end of the switching module is connected with the first battery stack interface, a second output end of the switching module is connected with the second battery stack interface, and the switching module is used for controlling one of the first output end and the second output end of the switching module to be connected to the input end of the switching module.

5. The detection circuit according to claim 4, characterized in that, the switching module is coupled with a first switch module, and the first switch module is used for controlling on-off between the first resistance module and the reference ground end; the switching module is coupled with a second switch module, and the second switch module is used for controlling on-off between the second resistance module and the reference ground end.

6. The detection circuit of claim 2, wherein, A third battery stack interface is connected with a negative electrode of the second battery monomer, a third connection line is connected between the third detection interface and the third battery stack interface, and the detection circuit further comprises: a third generating module, used for generating a constant current, and an output end of the third generating module is connected with the third battery stack interface; a third resistance module, a first end of the third resistance module is connected with the third detection interface, and a second end of the third resistance module is connected with the reference ground end; a third measuring module, a first end of the third measuring module is connected with the third detection interface, and a second end of the third measuring module is connected with the reference ground end, the third measuring module is used for measuring a voltage between the third detection interface and the reference ground end, and a ratio of an allowable connection resistance of the third connection line to a resistance value of the third resistance module is lower than a measurement resolution of the third measuring module.

7. The detection circuit of claim 2, wherein, The battery stack further comprises a third battery monomer, a negative electrode of the third battery monomer is connected with a positive electrode of the first battery monomer, a fourth battery stack interface is connected with a positive electrode of the third battery monomer, a fourth connection line is connected between the fourth detection interface and the fourth battery stack interface, and the detection circuit further comprises: a fourth generating module, used for generating a constant current, and an output end of the fourth generating module is connected with the fourth battery stack interface; a fourth resistance module, a first end of the fourth resistance module is connected with the fourth detection interface, and a second end of the fourth resistance module is connected with the reference ground end, a ratio of an allowable voltage deviation of the third battery monomer to a reference voltage of the third battery monomer is a third proportional value, and a ratio of an internal resistance of the third battery monomer to a resistance value of the fourth resistance module is smaller than the third proportional value; a fourth measuring module, a first end of the fourth measuring module is connected with the fourth detection interface, and a second end of the fourth measuring module is connected with the first detection interface, the fourth measuring module is used for measuring a voltage between the fourth detection interface and the first detection interface, and a ratio of an allowable connection resistance of the fourth connection line to a resistance value of the fourth resistance module is lower than a measurement resolution of the fourth measuring module.

8. The detection circuit of claim 7, wherein, Further comprising: a first switch module, a first end of the first switch module being connected with the first resistance module, a second end of the first switch module being connected with the reference ground terminal, the first switch module being configured to control the connection between the first resistance module and the reference ground terminal; a second switch module, a first end of the second switch module being connected with the second resistance module, a second end of the second switch module being connected with the reference ground terminal, the second switch module being configured to control the connection between the second resistance module and the reference ground terminal; a fourth switch module, a first end of the fourth switch module being connected with the fourth resistance module, a second end of the fourth switch module being connected with the reference ground terminal, the fourth switch module being configured to control the connection between the fourth resistance module and the reference ground terminal; the first switch module and the fourth switch module are coupled; the second switch module and the fourth switch module are the same module, and a first end of the fourth switch module is connected with the second resistance module.

9. The detection circuit according to any one of claims 1 to 8, characterized in that, Further comprising: a reference resistance, the reference resistance having a resistance value smaller than that of the first resistance module; a reference switch module, a first end of the reference switch module being connected with the first detection interface, a second end of the reference switch module being connected with a first end of the reference resistance, and a second end of the reference resistance being connected with the second detection interface.

10. A fuel cell system characterized by comprising: Comprise: a stack, the stack being provided with a first stack interface and a second stack interface, wherein a positive electrode of a first battery monomer of the stack is connected with the first stack interface, and a negative electrode of the first battery monomer is connected with the second stack interface; a first detection interface, the first detection interface being connected with the first stack interface through a first connection line; a second detection interface, the second detection interface being connected with the second stack interface through a second connection line; The detection circuit according to any one of claims 1 to 9, wherein an output end of the first generation module of the detection circuit is connected with the first stack interface, the first resistance module of the detection circuit is connected between the first detection interface and the reference ground terminal, and the first measurement module of the detection circuit is connected between the first detection interface and the second detection interface.

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