Fuel cell short circuit detection circuit

Abstract

The invention belongs to the technical field of fuel cells, and discloses a fuel cell short circuit detection circuit. The short-circuit detection circuit comprises a voltage source, a sampling circuit, a current control circuit, an operation indicating circuit, a first short-circuit indicating circuit and a second short-circuit indicating circuit, one end of the voltage source is connected with the operation indicating circuit, and the other end is connected with the first short-circuit indicating circuit and the second short-circuit indicating circuit through the current control circuit. The sampling circuit comprises a first interface, a first to-be-tested unit, a second interface, a second to-be-tested unit and a third interface. The first interface is connected with the first short circuit indicating circuit to detect whether the first to-be-detected unit is short-circuited; the second interface is connected with the operation indicating circuit to detect whether the circuit operates normally or not; and the third interface is connected with the second short circuit indicating circuit to detect whether the second to-be-detected unit is short-circuited. The fuel cell stack short circuit detection device is simple to operate, low in manufacturing cost, good in safety and capable of meeting the requirement for short circuit detection of the fuel cell stack in daily maintenance.

Description

Technical Field

[0001] This invention relates to the field of fuel cell technology, and in particular to a fuel cell short-circuit detection circuit. Background Technology

[0002] A fuel cell is a device that converts chemical energy into electrical energy. Its stack consists of multiple individual cells connected in series. Each individual cell comprises a bipolar plate and a membrane electrode assembly (MEA). In the absence of reactant gases, the bipolar plate and MEA can be considered as a resistor and a capacitor with parallel resistance, respectively. During the operation of a fuel cell, short circuits in the MEA can occur due to various reasons. Therefore, it is necessary to prioritize short circuit detection during maintenance to ensure operational safety.

[0003] Patent CN101131410B mentions a short circuit detection device and method for proton exchange membrane fuel cell membrane electrode. Based on the characteristic that the resistance of a single cell increases over time under normal conditions, the device determines whether there is a short circuit by observing whether the resistance changes.

[0004] Patent CN222882813U mentions a fuel cell stack short-circuit detection device that applies voltage to both ends of the stack and identifies short-circuited cells based on the different voltage signals of normal cells and short-circuited cells.

[0005] Existing technologies are generally used in the manufacturing process and require the integration of inspection, signal conversion, computers, and power supply equipment. Due to the complexity of operation and equipment, these technologies are difficult to carry and use during routine maintenance. Summary of the Invention

[0006] In view of this, the present invention provides a fuel cell short circuit detection circuit that can check the short circuit status of the fuel cell stack anytime and anywhere, ensuring safety during fuel cell stack maintenance.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] A fuel cell short-circuit detection circuit includes: a voltage source, a sampling circuit, a current control circuit, an operation indicator circuit, a first short-circuit indicator circuit, and a second short-circuit indicator circuit;

[0009] One end of the voltage source is connected to the operation indicator circuit, and the other end is connected to the first short-circuit indicator circuit and the second short-circuit indicator circuit through the current control circuit.

[0010] The sampling circuit includes a first interface, a first unit under test (DUT), a second interface, a second DUT, and a third interface, wherein the first interface, the first DUT, the second interface, the second DUT, and the third interface are connected in sequence; the first interface is connected to the first short-circuit indicator circuit to detect whether the first DUT is short-circuited; the second interface is connected to the operation indicator circuit to detect whether the circuit is operating normally; and the third interface is connected to the second short-circuit indicator circuit to detect whether the second DUT is short-circuited.

[0011] Furthermore, the first unit under test includes 1-2 fuel cell cells, and the second unit under test includes 1-2 fuel cell cells.

[0012] Furthermore, the voltage source has a voltage rating of 2-6V.

[0013] Furthermore, the operation indicator circuit, the first short-circuit indicator circuit, and the second short-circuit indicator circuit are light-emitting diodes.

[0014] Furthermore, the indicating current of the operation indicator circuit is 2-10mA.

[0015] Furthermore, the indicating current of the short-circuit indicator circuit is 1-5mA.

[0016] Furthermore, the current control circuit is a variable resistor.

[0017] Furthermore, the resistance of the variable resistor is 100Ω-10kΩ.

[0018] Furthermore, the short-circuit detection circuit also includes a protection circuit.

[0019] The beneficial effects of this invention are:

[0020] This invention provides a fuel cell short-circuit detection circuit. Using simple components to form a loop, it utilizes the difference in resistance between a single cell when short-circuited and when not short-circuited to quickly determine whether a single cell is short-circuited by measuring the current in the loop. This short-circuit detection circuit avoids potential differences greater than 10V in the fuel cell stack, preventing residual reactants inside the stack from reacting due to excessive potential differences during detection, thus improving the safety of the detection process. Furthermore, the short-circuit detection circuit of this invention is simple to operate, has low manufacturing cost, and is very suitable for routine maintenance. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of a fuel cell short-circuit detection circuit provided in an embodiment of the present invention;

[0022] Figure 2 This is a circuit diagram of a fuel cell short-circuit detection circuit provided in an embodiment of the present invention;

[0023] Figure 3 This is a combined circuit diagram of a fuel cell short-circuit detection circuit provided in an embodiment of the present invention. Detailed Implementation

[0024] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0025] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances. Furthermore, the terms "first" and "second" are merely used for descriptive distinction and have no special meaning.

[0026] like Figure 1 As shown, this embodiment provides a fuel cell short-circuit detection circuit, including: a voltage source, a sampling circuit, a current control circuit, an operation indicator circuit, a first short-circuit indicator circuit, and a second short-circuit indicator circuit; one end of the voltage source is connected to the operation indicator circuit, and the other end is connected to the first short-circuit indicator circuit and the second short-circuit indicator circuit through the current control circuit; the sampling circuit includes a first interface, a first unit under test, a second interface, a second unit under test, and a third interface, which are connected in sequence; the first interface is connected to the first short-circuit indicator circuit to detect whether the first unit under test is short-circuited; the second interface is connected to the operation indicator circuit to detect whether the circuit is operating normally; the third interface is connected to the second short-circuit indicator circuit to detect whether the second unit under test is short-circuited.

[0027] The first test unit includes 1-2 fuel cell cells, and the second test unit includes 1-2 fuel cell cells. Specifically, in this embodiment, as follows... Figure 2 As shown, the first unit under test includes two fuel cell cells, and the second unit under test includes two fuel cell cells. Each cell is equivalent to a 30mF capacitor in the circuit.

[0028] The voltage source voltage is 2-6V. Specifically, in this embodiment, the voltage source voltage is 3V.

[0029] The operation indicator circuit, the first short-circuit indicator circuit, and the second short-circuit indicator circuit are all LEDs. The indicating current of the operation indicator circuit is 2-10mA, and the indicating current of the short-circuit indicator circuit is 1-5mA. Specifically, in this embodiment, the indicating current of the operation indicator circuit is 3mA, and the indicating current of the short-circuit indicator circuit is 1.8mA. Under normal circumstances, the current in the short-circuit indicator circuit is half the current of the operation indicator circuit, i.e., 1.5mA. When a short circuit occurs, its current will oscillate at around 2mA for a period of time.

[0030] The current control circuit is a variable resistor with a resistance value of 100Ω-10kΩ. Specifically, in this embodiment, the variable resistor has a resistance value of 1kΩ and is used to control the magnitude of the aforementioned current. In practical applications, long-term use will cause changes in the capacitance of the circuit and the single battery. In this case, the value of the variable resistor should be adjusted according to the operation indicator circuit and the short-circuit indicator circuit to ensure that the current meets the test conditions again.

[0031] The short-circuit detection circuit also includes a protection circuit. Specifically, in this embodiment, a protection resistor is connected in parallel for each light-emitting diode.

[0032] Furthermore, this embodiment also provides a combination method for short-circuit detection circuits, such as... Figure 3 As shown, it includes two short-circuit detection circuits. The two short-circuit detection circuits are separated by four individual cells to avoid mutual interference between the detection circuits.

[0033] Therefore, it should be noted that when using this short-circuit detection circuit combination, two rounds of testing are required: the first round tests half of the individual cells in the fuel cell stack, and the second round tests the remaining half of the individual cells. Preferably, this testing method can be automated by adding a chip to the circuit.

[0034] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art will be able to make various obvious changes, readjustments, and substitutions without departing from the scope of protection of the present invention. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A short-circuit detection circuit for a fuel cell, characterized in that, include: Voltage source, sampling circuit, current control circuit, operation indicator circuit, first short circuit indicator circuit and second short circuit indicator circuit; One end of the voltage source is connected to the operation indicator circuit, and the other end is connected to the first short-circuit indicator circuit and the second short-circuit indicator circuit through the current control circuit. The sampling circuit includes a first interface, a first unit under test (DUT), a second interface, a second DUT, and a third interface, wherein the first interface, the first DUT, the second interface, the second DUT, and the third interface are connected in sequence; the first interface is connected to the first short-circuit indicator circuit to detect whether the first DUT is short-circuited; the second interface is connected to the operation indicator circuit to detect whether the circuit is operating normally; and the third interface is connected to the second short-circuit indicator circuit to detect whether the second DUT is short-circuited.

2. The short-circuit detection circuit according to claim 1, characterized in that, The first unit under test includes 1-2 fuel cell cells, and the second unit under test includes 1-2 fuel cell cells.

3. The short-circuit detection circuit according to claim 1, characterized in that, The voltage source has a voltage rating of 2-6V.

4. The short-circuit detection circuit according to claim 1, characterized in that, The operation indicator circuit, the first short-circuit indicator circuit, and the second short-circuit indicator circuit are light-emitting diodes.

5. The short-circuit detection circuit according to claim 3, characterized in that, The indicating current of the operation indicator circuit is 2-10mA.

6. The short-circuit detection circuit according to claim 3, characterized in that, The short-circuit indicator circuit has an indicating current of 1-5mA.

7. The short-circuit detection circuit according to claim 1, characterized in that, The current control circuit is a variable resistor.

8. The short-circuit detection circuit according to claim 6, characterized in that, The resistance of the variable resistor is 100Ω-10kΩ.

9. The short-circuit detection circuit according to claim 1, characterized in that, The short-circuit detection circuit also includes a protection circuit.

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