Fuel cell stack short circuit detection device

Abstract

The utility model discloses a fuel cell stack short circuit detection device which is characterized in that an electrode of a stack to be detected is connected with a power supply, each metal bipolar plate of the stack is electrically connected with a voltage acquisition joint, and the voltage acquisition joint is connected with a voltage monitoring unit through a wire harness and outputs acquired signals to the voltage monitoring unit. The voltage monitoring unit is connected through a wire harness and outputs collected signals to the CAN signal analysis device, and the CAN signal analysis device is communicated with a computer. The device does not involve hydrogen, and is simple in operation method, high in safety, low in cost and obvious in detection effect.

Description

Technical Field

[0001] The utility model relates to the field of fuel cells, and relates to a fuel cell stack short circuit detection device and method. Background Art

[0002] Fuel cells have many advantages such as high efficiency, fast start-up, no noise and no pollution, and have developed rapidly in recent years. Proton exchange membrane fuel cells are currently widely used in commercial vehicles and passenger cars, mainly reflected in the rapid iteration and development of fuel cell engines and fuel cell stacks. The demand for fuel cell stacks has therefore increased year by year, bringing great challenges to the production of stacks and the failure diagnosis of stacks.

[0003] During the production of the battery stack, due to many problems such as the curling of the metal bipolar plate or the defects of the membrane electrode itself, it is easy to cause the battery stack to short-circuit after stacking. During the application of the battery stack, there will also be various failures, especially the membrane electrode or bipolar plate being burned through. Therefore, it is particularly important to determine whether the battery stack has a short-circuit phenomenon and the location of the short-circuit. Existing short circuit detection devices and methods, for example, a public document with publication number CN101131410A, publication date 2008-02-27, and patent name "A proton exchange membrane fuel cell membrane electrode short circuit detection device and detection method", discloses a proton exchange membrane fuel cell membrane electrode short circuit detection device and detection method, the device is to connect two conductive plates to a DC power supply respectively, and a resistance meter is connected in series on the connecting line; the method is to clamp the membrane electrode to be detected between the two conductive plates, apply a small constant current to the membrane electrode, and record the change of the resistance value on the resistance meter over time. If the resistance value continues to increase with time, then the membrane electrode to be detected is not short-circuited; if the resistance value is constant and does not change with time, then the membrane electrode to be detected has a short-circuit point.

[0004] Existing detection devices are mainly used for single membrane electrode products to detect original defects (such as pinholes) of membrane electrodes and short circuits of membranes caused by the processing process. However, after the membrane electrode is mass-produced, it cannot be guaranteed that the membrane electrode will be inspected during the off-line process. When the membrane electrode is used in the stack, there is also an important component, the bipolar plate, which can also cause short circuit problems. Therefore, there is an urgent need for a fuel cell stack short circuit detection device and method. Summary of the invention

[0005] The technical problem to be solved by the utility model is to realize a detection device for judging whether a battery stack has a short circuit problem and which battery the short circuit occurs in.

[0006] In order to achieve the above-mentioned purpose, the technical solution adopted by the utility model is: a fuel cell stack short-circuit detection device, the electrodes of the stack to be detected are connected to the power supply, each metal bipolar plate of the stack is electrically connected to the voltage acquisition connector, the voltage acquisition connector is connected through a wiring harness and outputs the collected signal to the voltage monitoring unit, the voltage monitoring unit is connected through a wiring harness and outputs the collected signal to a CAN signal analysis device, and the CAN signal analysis device communicates with a computer.

[0007] The battery stack consists of a current collecting plate, a metal bipolar plate, a membrane electrode, an insulating plate and an end plate. The current collecting plate is provided with two plates for clamping the stacked metal bipolar plates and membrane electrode. An insulating plate is provided on the outer side of the current collecting plate, and an end plate is provided on the outer side of the insulating plate.

[0008] The power source is a mobile power source, and the positive and negative electrodes of the mobile power source are respectively connected to the positive and negative electrodes of the battery stack current collecting plate through a wiring harness.

[0009] The target voltage delivered to the battery stack by the mobile power supply is 50mV*number of battery cells.

[0010] The voltage collection connector is electrically connected to the metal bipolar plate by clamping or plugging.

[0011] The voltage monitoring unit is provided with a plurality of signal input interfaces, and each of the signal input interfaces is connected to a voltage acquisition connector through an independent wiring harness.

[0012] The voltage monitoring unit transmits the information to the CAN signal analysis device in the form of a CAN message. The computer is a notebook computer, and the display screen of the computer is used to display the value of each collected voltage signal.

[0013] The advantage of the utility model is that a voltage of 50mV×the number of cells is applied between the positive and negative electrodes of the battery stack through a mobile power supply, and then the voltage signal is transmitted to the voltage monitoring unit CVM (cell voltage monitor) through the single-chip voltage acquisition connector CVP (cell voltage pickup), and the computer software identifies and displays the voltage signal of CVM. By judging whether all the collected single-chip voltage signals are 0mV, it is judged whether the battery stack has a short circuit problem and which battery the short circuit occurs in. The device does not involve hydrogen, has a simple operation method, high safety, low cost, and obvious detection effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The following is a brief description of the contents expressed in each figure in the utility model specification and the marks in the figure:

[0015] Figure 1 It is a structural schematic diagram of a fuel cell stack short circuit detection device;

[0016] Figure 2 This is a schematic diagram of the measured results of the application of the battery stack short-circuit detection device;

[0017] The marks in the above figures are: 1. Mobile power supply; 2. Wiring harness; 3. Current collector; 4. Metal bipolar plate; 5. Membrane electrode; 6. Insulating plate; 7. End plate; 8. Voltage collection connector; 9. Computer; 10. Voltage monitoring unit; 11. CAN signal analysis device. DETAILED DESCRIPTION

[0018] The following is a further detailed description of the specific implementation methods of the present invention, such as the shapes and structures of the components involved, the relative positions and connection relationships between the components, the functions and working principles of the components, the manufacturing process and the operation and use methods, etc., through the description of the embodiments with reference to the accompanying drawings, so as to help those skilled in the art to have a more complete, accurate and in-depth understanding of the inventive concept and technical solution of the present invention.

[0019] The battery stack to be tested consists of a current collecting plate 3, a metal bipolar plate 4, a membrane electrode 5, an insulating plate 6 and an end plate 7, wherein the metal bipolar plate 4 and the membrane electrode 5 are arranged in multiple layers at intervals from each other, clamped on the outside by two current collecting plates 3, the outsides of the two current collecting plates 3 are clamped by insulating plates 6, and end plates 7 are arranged on the outsides of the two insulating plates 6.

[0020] The electrodes of the battery stack to be tested are connected to a power source, and the power source preferably adopts a mobile power source 1. The positive and negative electrodes of the mobile power source 1 are respectively connected to the positive and negative electrodes of the battery stack current collector 3 through a wiring harness 2. Through the mobile power source 1, a voltage of 50mV×the number of battery cells is applied to the positive and negative electrodes of the battery stack. Each metal bipolar plate 4 of the battery stack is electrically connected to a voltage acquisition connector 8CVP (cell voltage pick-up). The voltage acquisition connector 8 is electrically connected to the metal bipolar plate 4 by clamping or plugging. The voltage acquisition connector 8 is connected through the wiring harness 2 and outputs the collected signal to the voltage monitoring unit 10CVM (cell voltage monitor). The voltage monitoring unit 10 is connected through the wiring harness 2 and outputs the collected signal to the CAN signal analysis device 11. The voltage monitoring unit 10 is provided with multiple signal input interfaces, and each signal is connected to a voltage acquisition connector 8 through an independent wiring harness 2. The CAN signal analysis device 11 communicates with the computer 9. The voltage monitoring unit 10 transmits the CAN signal to the CAN signal analysis device 11 in the form of a CAN message. The computer 9 is a laptop computer 9, and the display screen of the computer 9 is used to display the value of each collected voltage signal. By judging whether all the collected single-chip voltage signals are 0mV, it is judged whether the battery stack has a short circuit problem and which battery the short circuit occurs in.

[0021] Before the device works, the voltage monitoring unit 10 must be powered. When testing the short circuit of the battery stack, adjust the mobile power supply 1 to the target voltage value (50mV*number of battery cells. If the voltage value is too high, the battery stack will be damaged) to apply the target voltage to the positive and negative electrodes of the battery stack. While applying the voltage, the voltage acquisition connector 8 on each of the two bipolar plates transmits the collected voltage signal to the voltage monitoring unit 10 through the wiring harness 2. After the voltage monitoring unit 10 completes the signal reception, it transmits the voltage signal to the CAN signal analysis device 11 in the form of a CAN message, and then displays the voltage signal through the dedicated software on the laptop computer 9.

[0022] Test principle: Each battery in the battery stack has a capacitive effect. When voltage is applied to both ends of the battery, it is equivalent to charging the battery. If the battery is not short-circuited, the voltage value can be detected. If the battery is short-circuited, the detected voltage value is 0mV.

[0023] By judging whether the voltage value of each battery cell on the stack is 0mV, it is determined whether the stack has a short circuit problem. If there is no 0mV signal, the stack has no short circuit problem. If one or several cells have a 0mV signal, it can be determined that the stack has a short circuit problem. The short circuit position is the number of cells corresponding to the 0mV voltage value. If a short circuit problem and short circuit position are detected, it can be further determined by visual inspection whether the bipolar plate is abnormal, or the stack can be disassembled to analyze whether the membrane electrode 5 is abnormal.

[0024] like Figure 2 As shown, the test results obtained by applying the battery stack short-circuit detection device and method of the present invention show that there is a short circuit in the battery stack, and the short circuit occurs at the 5th cell.

[0025] The present invention is described above by way of example in conjunction with the accompanying drawings. It is obvious that the specific implementation of the present invention is not limited to the above-mentioned method. As long as various non-substantial improvements are made using the method concept and technical solution of the present invention, or the concept and technical solution of the present invention are directly applied to other occasions without improvement, they are all within the protection scope of the present invention.

Claims

1. A fuel cell stack short circuit detection device, wherein the electrodes of the stack to be detected are connected to a power supply, characterized in that: Each metal bipolar plate of the battery stack is electrically connected to a voltage collection connector, and the voltage collection connector is connected via a wiring harness and outputs the collected signal to a voltage monitoring unit, and the voltage monitoring unit is connected via a wiring harness and outputs the collected signal to a CAN signal analysis device, and the CAN signal analysis device communicates with a computer.

2. The fuel cell stack short circuit detection device according to claim 1, characterized in that: The battery stack consists of a current collecting plate, a metal bipolar plate, a membrane electrode, an insulating plate and an end plate. The current collecting plate is provided with two plates for clamping the stacked metal bipolar plates and membrane electrode. An insulating plate is provided on the outer side of the current collecting plate, and an end plate is provided on the outer side of the insulating plate.

3. The fuel cell stack short circuit detection device according to claim 2, characterized in that: The power source is a mobile power source, and the positive and negative electrodes of the mobile power source are respectively connected to the positive and negative electrodes of the battery stack current collecting plate through a wiring harness.

4. The fuel cell stack short circuit detection device according to claim 3, characterized in that: The target voltage delivered to the battery stack by the mobile power supply is 50mV*number of battery cells.

5. The fuel cell stack short circuit detection device according to any one of claims 1 to 4, characterized in that: The voltage collection connector is electrically connected to the metal bipolar plate by clamping or plugging.

6. The fuel cell stack short circuit detection device according to claim 5, characterized in that: The voltage monitoring unit is provided with a plurality of signal input interfaces, and each of the signal input interfaces is connected to a voltage acquisition connector through an independent wiring harness.

7. The fuel cell stack short circuit detection device according to claim 6, characterized in that: The voltage monitoring unit transmits the information to the CAN signal analysis device in the form of a CAN message. The computer is a notebook computer, and the display screen of the computer is used to display the value of each collected voltage signal.

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