Hydrogen fuel cell protection system and control method

Abstract

The invention relates to the technical field of fuel cells, in particular to a hydrogen fuel cell protection system and a control method, and the system comprises a relay array which comprises a plurality of relays, and two endpoints of each relay are connected in parallel to the positive electrode and the negative electrode of a corresponding single cell; the shut-off valve array comprises a plurality of shut-off valves, each shut-off valve is arranged on an anode intake manifold of the corresponding single cell and controls the anode intake manifold to be opened and closed, the anode intake manifolds and a hydrogen intake manifold of the hydrogen fuel cell are connected with a controller, and the controller is connected with the relay array and the shut-off valve array. And the fault level of each single battery is determined according to the operation parameters of each single battery, a control instruction is generated according to the fault level, and at least one of the relay array and the stop valve array is controlled by using the control instruction. Therefore, the problems of irreversible carbon corrosion reaction and the like of the anode of the faulted battery caused by reverse current of the battery after the fuel battery single battery breaks down and hydrogen is cut off are solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of fuel cells, in particular to a hydrogen fuel cell protection system and a control method. BACKGROUND

[0002] A hydrogen fuel cell stack is usually composed of hundreds of single cells connected in series to build a high-voltage output that meets the power demand. In actual operation, individual single cells may fail due to water flooding, gas starvation, catalyst poisoning, etc., resulting in a significant drop in output voltage or even failure. Due to the series structure of the stack, the failure of a single cell will restrict the performance of the entire stack like a "short board" of a barrel, and even trigger a chain reaction, threatening the safety of the stack.

[0003] In related technologies, an online fault isolation scheme is proposed and applied, which can quickly diagnose the faulty single cell and stop its electrochemical reaction by cutting off the anode hydrogen supply valve of the cell, thereby achieving fault isolation and fault-tolerant operation of the system. However, the scheme of cutting off hydrogen alone has technical defects: in a series circuit, the faulty cell with cut-off hydrogen is still exposed to air (with oxygen) on the cathode side. Since the current loop is not disconnected, the current generated by the healthy cell will be forced to pass through the faulty cell in the opposite direction, making it a load for electrolysis, and causing reverse current corrosion of the cell, resulting in irreversible permanent damage. SUMMARY

[0004] The present application provides a hydrogen fuel cell protection system and a control method to solve the problem of irreversible carbon corrosion reaction of the anode of the faulty cell caused by reverse current of the cell after the hydrogen is cut off when a single cell of the fuel cell fails.

[0005] The first aspect of the present application provides a hydrogen fuel cell protection system, which includes a plurality of single cells in the stack of the hydrogen fuel cell, and comprises: a relay array, the relay array includes a plurality of relays, two endpoints of each relay are connected in parallel to the positive and negative electrodes of the corresponding single cell, and a bypass channel is formed between the two endpoints when the relay contact is closed; a cut-off valve array, the cut-off valve array includes a plurality of cut-off valves, each cut-off valve is arranged on the anode gas inlet manifold of the corresponding single cell, and controls the opening and closing of the anode gas inlet manifold, the anode gas inlet manifold is connected with the hydrogen gas inlet manifold of the hydrogen fuel cell; a controller, the controller is connected with the relay array and the cut-off valve array respectively, determines the fault level of each single cell according to the operating parameters of the single cell, generates a control instruction according to the fault level, and controls at least one of the relay array and the cut-off valve array by using the control instruction to close at least one of the corresponding relays and open at least one of the corresponding cut-off valves.

[0006] Optionally, each relay in the relay array has a normally open contact before receiving a closing instruction from the controller.

[0007] Optionally, the bypass channel has a resistance value less than a preset resistance value.

[0008] Optionally, each shutoff valve in the shutoff valve array has an inlet end connected to an output end of an anode gas manifold, and has an outlet end connected to an anode chamber of a corresponding single cell.

[0009] The second aspect of the present application provides a vehicle comprising the hydrogen fuel cell protection system as described in the above embodiments.

[0010] The third aspect of the present application provides a control method of a hydrogen fuel cell protection system, the method being applied to the controller of the hydrogen fuel cell protection system as described in the above embodiments, and the method comprising the following steps: obtaining operation data of the hydrogen fuel cell; identifying an operation parameter of each single cell from the operation data; determining a failure level of each single cell according to the operation parameter of the single cell, generating a control instruction according to the failure level, and controlling at least one of the relay array and the shutoff valve array by using the control instruction to close at least one corresponding relay and to open at least one corresponding shutoff valve.

[0011] Optionally, the step of determining the failure level of each single cell according to the operation parameter of the single cell comprises the following steps: identifying a potential difference value, a voltage change rate, and a cell temperature of the single cell in the operation parameter; determining the failure level as a first failure level if the potential difference value of the single cell is less than or equal to a first difference threshold value, or the voltage change rate is less than or equal to a preset change rate, or the cell temperature is greater than a temperature threshold value; and determining the failure level as a second failure level if the potential difference value of the single cell is greater than the first difference threshold value and less than a second difference threshold value, the voltage change rate is greater than the preset change rate, and the cell temperature is less than or equal to the temperature threshold value.

[0012] Optionally, before the step of determining the failure level of each single cell according to the operation parameter of the single cell, the method comprises the following steps: identifying a corresponding identifier of a failed single cell; and opening a corresponding shutoff valve according to the corresponding identifier of the failed single cell.

[0013] Optionally, the step of generating a control instruction according to the failure level comprises the following steps: generating a control instruction to close a relay corresponding to the single cell if the failure level is the first failure level; and identifying a potential difference value of the single cell within a target time length, and generating a corresponding control instruction according to the potential difference value of the single cell within the target time length if the failure level is the second failure level.

[0014] Optionally, generating corresponding control commands based on the potential difference of individual cells within the target duration includes: if the potential difference of individual cells within the target duration does not reach a preset difference range, generating a control command to close the relay corresponding to the individual cell; if the potential difference is within the preset difference range within the target duration, controlling the hydrogen fuel cell protection system to perform a recovery action.

[0015] Therefore, this application has at least the following beneficial effects: This application can fundamentally eliminate reverse polarity corrosion caused by faulty cells being forced to carry reverse current in the series circuit, by setting corresponding parallel relays and shut-off valves for each individual cell. The controller can determine the fault level based on real-time operating parameters and coordinate the execution of dual protection of cutting off hydrogen and electrical short circuit. This effectively avoids irreversible damage such as carbon carrier corrosion and membrane electrode breakdown, thereby significantly improving the fault-tolerant operation capability and overall service life of the fuel cell stack and ensuring system safety and reliability.

[0016] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0017] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein: Figure 1 This is a block diagram of a hydrogen fuel cell protection system according to an embodiment of this application; Figure 2 This is an example diagram of a hydrogen fuel cell protection system provided according to an embodiment of this application; Figure 3 This is a flowchart of a control method for a hydrogen fuel cell protection system provided according to an embodiment of this application; Figure 4 This is a logical schematic diagram of the control strategy of the hydrogen fuel cell protection system provided according to an embodiment of this application.

[0018] Explanation of reference numerals in the attached figures: relay array 100, shut-off valve array 200, controller 300, and hydrogen fuel cell protection system 10. Detailed Implementation

[0019] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application.

[0020] In related technologies, a method and system for fault isolation of fuel cells based on hydrogen management and temperature co-diagnosis of individual cells can quickly cut off the hydrogen supply to the faulty cell, thereby stopping its operation and achieving online isolation and fault-tolerant operation.

[0021] However, under reverse polarity conditions, an oxygen evolution reaction occurs inside the faulty battery, and a violent water electrolysis reaction (2H₂O→O₂+4H₂O) occurs on the anode side. + +4e - And the even more deadly carbon corrosion reaction (C + 2H₂O → CO₂ + 4H₂O) + +4e - Carbon corrosion rapidly destroys the carbon support of the catalyst layer, causing catalyst detachment, loss of support for the proton exchange membrane, and eventual breakdown, resulting in irreversible and permanent damage. This means that a battery that could potentially be recovered through a simple purging process can be completely rendered unusable within minutes due to reverse polarity.

[0022] Therefore, the relevant technology achieves isolation by cutting off the hydrogen supply to the faulty individual cell. However, this only stops the chemical reaction (anode side). In the series circuit, the cathode side of the faulty cell remains exposed to oxygen and is forced to become a load, undergoing "reverse electrolysis" by the current generated by other healthy cells, resulting in reverse polarity. Reverse polarity causes irreversible carbon corrosion at the anode of the faulty cell, destroying the carbon support of the catalyst layer within minutes, leading to catalyst shedding, proton exchange membrane breakdown, and permanent, devastating damage. A battery that fails due to a simple problem (such as instantaneous flooding) but is completely damaged by reverse polarity must be replaced by open-chain repair, which is extremely costly, complex, and may cause secondary damage to healthy cells during the repair process.

[0023] This application addresses the technical challenge of shorting the faulty cell after disconnecting hydrogen. This short circuit provides a stable, extremely low-impedance bypass, allowing the stack current to flow smoothly and protecting the cell from reverse polarity damage. It completely isolates the faulty cell from an electrical perspective, preserving its physical state and reducing interference with the overall electrical environment of the system. This completely prevents the cell from experiencing reverse current, fundamentally eliminating reverse polarity corrosion and thus maximizing the protection of the stack assets.

[0024] The hydrogen fuel cell protection system and control method of this application are described below with reference to the accompanying drawings.

[0025] Specifically, Figure 1 This is a block diagram of a hydrogen fuel cell protection system according to an embodiment of this application.

[0026] like Figure 1 As shown, the hydrogen fuel cell protection system 10 includes: a relay array 100, a shut-off valve array 200, and a controller 300.

[0027] The relay array 100 includes multiple relays, each with two terminals connected in parallel to the positive and negative terminals of the corresponding single cell. When the relay contacts are closed, a bypass channel is formed between the two terminals. The shut-off valve array 200 includes multiple shut-off valves, each located on the anode intake manifold of the corresponding single cell, controlling the opening and closing of the anode intake manifold. The anode intake manifold is connected to the hydrogen intake main of the hydrogen fuel cell. The controller 300 is connected to both the relay array and the shut-off valve array. It determines the fault level of each single cell based on its operating parameters, generates control commands based on the fault level, and uses these commands to control at least one of the relay array and the shut-off valve array to close the corresponding relay and open at least one of the corresponding shut-off valves.

[0028] It is understood that the embodiments of this application can set up a relay array connected in parallel with each individual cell and a shut-off valve array located on the anode intake manifold. The controller can determine the fault level in real time based on the operating parameters of the individual cells, and then coordinate the closing of the relays and the opening of the shut-off valves. This can quickly cut off the hydrogen supply to the individual cell when it fails and simultaneously establish a low-impedance bypass channel. This effectively avoids reverse polarity corrosion caused by the reverse current of the faulty cell, thereby preventing irreversible damage such as carbon corrosion of the catalyst support and breakdown of the proton exchange membrane. This significantly improves the operational safety, reliability and service life of the fuel cell stack. At the same time, it supports the system to enter a controllable degraded fault-tolerant operation mode after a fault, ensuring the continuous availability of the vehicle or equipment.

[0029] In this embodiment, the contacts of each relay in the relay array 100 are normally open until a closing command is received from the controller.

[0030] It is understood that in the relay array of this application embodiment, each relay keeps its contacts open until it receives a closing command from the controller, ensuring that no interference or additional loss occurs to the electrical path of the individual cells during normal operation of the stack, and maintaining the original electrical performance and stability of the system. At the same time, this design avoids the risk of short circuit caused by malfunction, improves the safety and reliability of the entire protection system, and can quickly respond to control commands to achieve precise bypass when a fault occurs, effectively balancing uninterrupted operation under normal conditions and rapid protection under fault conditions.

[0031] In this embodiment, the resistance value of the bypass channel is less than a preset value.

[0032] The preset threshold can be set according to actual needs, for example, 10mΩ, without specific limitation.

[0033] It is understood that in this embodiment, the resistance value of the bypass channel can be less than the preset resistance value, ensuring that after the relay is closed, most of the stack current can preferentially flow through the low impedance path, effectively bypassing the faulty cell, significantly reducing the reverse voltage and current density it bears, thereby completely suppressing the reverse polarity electrolysis reaction and the irreversible damage such as carbon corrosion caused therefrom, improving the protection effect and ensuring the stability and safety of the overall operation of the stack.

[0034] It should be noted that the closed-loop resistance of the bypass channel is much smaller than the minimum equivalent internal resistance of the individual cell in the reverse polarity state, so as to ensure that the current flowing through the faulty individual cell is insufficient to trigger a significant carbon corrosion reaction under the maximum operating current of the stack.

[0035] In this embodiment, the inlet end of each shut-off valve in the shut-off valve array is connected to the output end of the anode intake manifold, and the outlet end of each shut-off valve is connected to the anode chamber of the corresponding single cell.

[0036] It is understood that in this embodiment, the inlet end of each shut-off valve in the shut-off valve array is connected to the output end of the anode intake manifold, and the outlet end is connected to the anode chamber of the corresponding single cell. This enables the controller to independently and accurately cut off the hydrogen supply to any faulty single cell, effectively preventing it from continuing to participate in the electrochemical reaction, avoiding voltage collapse and reverse polarity risks caused by local gas shortage or abnormal reaction, while not affecting the normal gas supply and operation of other healthy single cells, thus improving the accuracy of system fault isolation and the overall reliability of operation.

[0037] It should be noted that by placing the shut-off valve as close as possible to the anode chamber of the individual cell, the hydrogen gas supply to the specific faulty cell can be cut off as quickly as possible after the command is issued. This minimizes the amount of hydrogen gas remaining in the dead zone (pipeline volume) after the valve from continuing to participate in the reaction, thereby achieving the most thorough chemical isolation of the cell.

[0038] The hydrogen fuel cell protection system proposed in this application, by setting up a relay array connected in parallel with each individual cell and a shut-off valve array located on the anode intake manifold, and by having the controller determine the fault level in real time based on the operating parameters of the individual cells, can coordinate the closing of the relays and the opening of the shut-off valves. This system can quickly cut off the hydrogen supply to the individual cell when it fails and simultaneously establish a low-impedance bypass channel, effectively preventing reverse polarity corrosion caused by the reverse current of the faulty cell. This prevents irreversible damage such as catalyst carrier carbon corrosion and proton exchange membrane breakdown, significantly improving the operational safety, reliability and service life of the fuel cell stack. At the same time, it supports the system to enter a controllable degraded fault-tolerant operation mode after a fault, ensuring the continuous availability of the vehicle or equipment.

[0039] The following will combine Figure 2The hydrogen fuel cell protection system of this application is described in detail below: The fuel cell stack consists of multiple individual cells connected in series. Each individual cell has a positive and a negative terminal, and they are electrically connected to form an overall electrical circuit. On the electrical side of the fuel cell stack, a relay array 100 is provided, in which relays 1 to n are connected in parallel between the positive and negative terminals of individual cells 1 to n, respectively. The contacts of each relay remain open when no control command is received. When the controller 300 issues a closing command, the corresponding relay contacts close, forming a low-impedance bypass channel across the individual cell, which can achieve near-zero resistance current shunting.

[0040] On the gas path side, a shut-off valve array 200 is provided, wherein shut-off valves 1 to n are respectively installed on the anode inlet manifolds branching off from the hydrogen inlet main pipe. The inlet end of each shut-off valve is connected to the output end of the anode inlet manifold, and the outlet end is connected to the anode chamber of the corresponding single cell, for independently controlling the hydrogen supply of each single cell. When a single cell fails, the controller 300 determines the fault level based on its operating parameters such as voltage, current, and temperature, generates a control command, controls the corresponding relay to close to establish a bypass channel, and simultaneously controls the corresponding shut-off valve to open to cut off the hydrogen supply.

[0041] Specifically, the core component of the fuel cell stack short-circuit protection system is a series of high-power, high-speed relays (or solid-state switches or contactors) forming a short-circuit relay array. The two main terminals of each relay (relay 1, relay 2, etc.) are directly connected in parallel to the positive and negative terminals of the corresponding individual battery cell (cell cell 1, cell cell 2, etc.). Under normal circumstances, the relay contacts are normally open and have no effect on the battery circuit. In case of a fault, the relay receives a controller command to close, providing a near-zero-resistance bypass path for the battery current. When the controller (such as the FCU) determines that a cell cell has failed and performs an isolation operation (such as closing its anode hydrogen valve), or simultaneously, it immediately sends a closing command to the relay connected in parallel with the faulty cell. After the relay closes, a near-zero-resistance bypass path is provided for the current flowing through the faulty cell. The current will preferentially pass through this low-impedance path, thus bypassing the faulty cell and preventing it from experiencing reverse current, fundamentally eliminating the occurrence of reverse polarity electrolysis.

[0042] For example, when cell 2 experiences an abnormal voltage drop or reverse polarity trend, the controller detects this signal and immediately sends a closing command to relay 2, causing the relay 2 contacts to close and short-circuiting cell 2, preventing it from participating in the main circuit current flow. Simultaneously, it sends a closing command to shut-off valve 2, interrupting its anode hydrogen supply. At this time, the stack current bypasses cell 2 via the low-impedance path formed by relay 2, preventing it from being subjected to reverse polarity corrosion caused by reverse current, while other cells can still operate normally, ensuring the overall stability of the stack output. Thus, through a dual isolation strategy of electrical and gas paths, rapid and precise protection of faulty cells is achieved, effectively preventing cascading damage caused by localized faults, improving the safety and reliability of the fuel cell system, and making it suitable for various applications such as vehicle-mounted, energy storage, and stationary power generation.

[0043] This application also provides a vehicle including a hydrogen fuel cell protection system as described in the above embodiments.

[0044] Figure 3 This is a schematic flowchart illustrating a control method for a hydrogen fuel cell protection system provided in an embodiment of this application.

[0045] like Figure 3 As shown, the control method for the hydrogen fuel cell protection system is applied to the controller of the hydrogen fuel cell protection system, wherein the method includes the following steps: In step S101, the operating data of the hydrogen fuel cell is acquired. It is understood that the embodiments of this application can obtain the operating data of hydrogen fuel cells, effectively determine whether the working state of the fuel cells is stable, and whether there are potential failure risks, so as to take corresponding measures for adjustment or maintenance.

[0046] It should be noted that the operating data of hydrogen fuel cells includes key parameters such as individual cell voltage, total stack voltage, current density, temperature distribution, humidity level, and the supply rate of hydrogen and oxygen, without specific limitations.

[0047] In step S102, the operating parameters of each individual cell are identified from the operating data.

[0048] It is understood that the embodiments of this application can identify the operating parameters of each individual cell from the operating data, enabling refined monitoring and independent evaluation of the operating status of each individual cell in the stack, so as to facilitate subsequent judgment of the health status and fault level of the individual cells.

[0049] It should be noted that the operating parameters of a single cell include the absolute value of the single cell voltage (i.e., the potential difference between the positive and negative electrodes), the rate of voltage change, and the single cell temperature.

[0050] In step S103, the fault level of each individual battery is determined based on the operating parameters of each individual battery, and a control command is generated based on the fault level. The control command is used to control at least one of the relay array and the shut-off valve array to close the corresponding relay and open at least one of the corresponding shut-off valve.

[0051] It is understood that the embodiments of this application can intelligently determine the fault level of each individual battery by analyzing the operating parameters of each individual battery in real time, and generate differentiated control commands according to different levels to realize the coordinated or selective operation of the relay array and the shut-off valve array. This graded response mechanism can not only take conservative measures to avoid unnecessary system intervention for minor faults, but also perform rapid and thorough hydrogen cut-off and electrical short-circuit dual protection for serious faults. In this way, while ensuring that the faulty battery is effectively isolated to prevent reverse polarity damage, the continuous and stable operation of the stack system is maintained to the maximum extent, which significantly improves the accuracy of protection, system fault tolerance and overall reliability.

[0052] In this embodiment of the application, the fault level of a single battery cell is determined based on the operating parameters of each single battery cell, including: identifying the potential difference, voltage change rate, and battery temperature of the single battery cell in the operating parameters; if the potential difference of the single battery cell is less than or equal to a first difference threshold, or the voltage change rate is less than or equal to a preset change rate, or the battery temperature is greater than a temperature threshold, then the fault level is determined to be a first fault level; if the potential difference of the single battery cell is greater than the first difference threshold and less than a second difference threshold, and the voltage change rate is greater than a preset change rate, and the single battery temperature is less than or equal to a temperature threshold, then the fault level is determined to be a second fault level.

[0053] The first difference threshold, preset change rate, and temperature threshold can all be set according to actual needs. For example, the first difference threshold is 0V, the preset change rate is -100 mV / s, and the temperature threshold is 85 ℃, without specific limitations.

[0054] It is understood that the embodiments of this application can identify the potential difference, voltage change rate, and battery temperature of individual cells, and distinguish the fault level according to preset thresholds, thereby achieving accurate identification and graded response to fault states. When the potential difference is less than or equal to the first difference threshold, or the voltage change rate is less than or equal to the preset change rate, or the battery temperature is higher than the temperature threshold, it is determined to be a first fault level, triggering an immediate short circuit and hydrogen cutoff to prevent severe reverse polarity damage. When all parameters are within a relatively controllable range, it is determined to be a second fault level, and a delayed judgment strategy is adopted to avoid excessive intervention in recoverable faults. This method takes into account both the timeliness of protection and the stability of operation, effectively suppressing irreversible damage and improving the safety, reliability, and service life of the fuel cell system.

[0055] In this embodiment of the application, before determining the fault level of a single cell based on the operating parameters of each single cell, the process includes: identifying the identifier corresponding to the faulty single cell; and disconnecting the corresponding shut-off valve based on the identifier corresponding to the faulty single cell.

[0056] It is understood that, before determining the fault level of a single battery cell based on operating parameters, the embodiments of this application can identify the corresponding identifier of the faulty single battery cell and immediately disconnect its corresponding shut-off valve. This can cut off the hydrogen supply to the battery in the first instance, preventing it from continuing to participate in the electrochemical reaction, effectively suppressing further voltage deterioration and the risk of local overheating. This pre-isolation measure provides a critical time window for subsequent fault level determination based on multiple parameters, while reducing the possibility of reverse polarity, improving the response speed and safety of the overall protection strategy, and laying the foundation for graded and precise control.

[0057] In this embodiment of the application, generating control instructions based on the fault level includes: if the fault level is a first fault level, generating a control instruction to close the relay corresponding to the single cell; if the fault level is a second fault level, identifying the potential difference value of the single cell within the target time period, and generating a corresponding control instruction based on the potential difference value of the single cell within the target time period.

[0058] It is understood that the embodiments of this application can generate corresponding control commands based on the fault level, enabling differentiated protection strategies to be implemented under different fault severity levels. When the fault level is the first fault level, a control command to close the corresponding relay is immediately generated to quickly establish a low-impedance bypass channel, completely blocking reverse current and preventing irreversible damage. When the fault level is the second fault level, the potential difference of the individual cells is continuously monitored within the target duration, and control commands are dynamically generated based on whether the potential difference recovers, avoiding unnecessary short-circuiting operations for self-healing faults. This mechanism takes into account both the timeliness of protection and the stability of system operation, effectively improving the fault tolerance and service life of the fuel cell stack.

[0059] In this embodiment of the application, a corresponding control command is generated based on the potential difference of a single cell within a target time period, including: if the potential difference of a single cell within the target time period does not reach a preset difference range, a control command to close the relay corresponding to the single cell is generated; if the potential difference is within the preset difference range within the target time period, the hydrogen fuel cell protection system is controlled to perform a recovery action.

[0060] The preset difference range can be set according to actual needs, for example, within ±30 mV, without specific limitations.

[0061] It is understood that the embodiments of this application can generate corresponding control commands based on the potential difference of individual cells within a target time period, enabling intelligent judgment and response to potential recoverable faults. If the potential difference of individual cells does not reach the preset difference range within the target time period, it indicates that the fault has not been resolved on its own, and the system will generate a control command to close the corresponding relay and activate electrical short-circuit protection to prevent reverse polarity damage. If the potential difference recovers to the preset difference range within the target time period, it is determined to be a reversible fault, and the system controls the hydrogen fuel cell protection system to perform recovery actions, such as restarting the hydrogen supply or adjusting operating parameters, to avoid unnecessary hardware intervention. This strategy effectively balances fault protection and system availability, improving the intelligence level and overall reliability of fuel cell operation.

[0062] It should be noted that the recovery process includes increasing the anode pressure, raising the stack operating temperature, applying a brief load pulse, and / or auxiliary anode purging. Specifically: Increasing Anode Pressure: Instantly increasing the anode pressure at the stack inlet by a preset small increment ΔP (e.g., 5-10 kPa) helps break through droplet blockage, propelling hydrogen through the water film to the catalyst layer. Increasing Stack Operating Temperature: Increasing the target stack operating temperature or coolant inlet temperature by a preset small increment ΔT (e.g., 2-5°C) reduces the water concentration within the membrane, increases the saturated vapor pressure of water, and thus accelerates the evaporation of liquid water within the electrodes. Applying a Brief Load Pulse: Controlling the stack output to deliver a brief current higher than currently required (a current pulse). Increasing the current enhances the rate of chemical reactions and heat generation within the battery, heating and drying the electrodes from the inside, helping to "burn off" excess moisture.

[0063] Auxiliary anode purging: Removes liquid water from the anode channels and catalyst layer pores caused by "flooding," restoring hydrogen transport channels. The controller instructs the anode hydrogen shut-off valve corresponding to the faulty cell to perform one or more short, low-flow-rate pulse openings. Each opening is extremely short (e.g., 50-200 milliseconds) to prevent excessive hydrogen influx. Sufficient intervals (e.g., 500-1000 milliseconds) are allowed after each opening to allow the gas flow to flush away and remove moisture. This process is repeated several times (e.g., 3-5 cycles).

[0064] According to the control method of the hydrogen fuel cell protection system proposed in this application, by acquiring operating data and identifying the operating parameters of each individual cell, the operating status of each individual cell can be perceived and accurately evaluated in real time. After determining the fault level based on the operating parameters, corresponding control commands are generated, which can coordinate the control of the relay array and the shut-off valve array to implement graded, rapid, and targeted protection measures for the faulty cell. In the event of a serious fault, the hydrogen gas is immediately short-circuited and cut off. In the event of a minor or recoverable fault, a delayed judgment and recovery mechanism is introduced to effectively prevent irreversible damage such as reverse polarity corrosion, significantly improve the safety, reliability, and service life of the fuel cell stack, and ensure that the system can still operate stably under certain fault conditions.

[0065] The following will combine Figure 4 The control method of the hydrogen fuel cell protection system of this application is described in detail, and the specific steps are as follows: S1: Multi-parameter fusion determination of single-cell battery X fault Based on the multi-parameter fusion fault diagnosis algorithm, a specific cell (denoted as cell X) in the fuel cell stack is determined to have a fault, and a fault alarm and cell identifier are sent to the controller.

[0066] S2: Execute Level 1 protection and close the hydrogen shut-off valve. Upon receiving a fault signal, the controller immediately generates and issues a first-priority control command: close the anolyte hydrogen shut-off valve of the faulty battery X. This aims to cut off the reactant supply to the faulty battery as quickly as possible, stopping its electrochemical reaction; this is the primary isolation measure.

[0067] S3: Real-time assessment of fault severity While executing the first-level protection, the controller simultaneously calls the fault severity judgment algorithm to quickly analyze the real-time data of the faulty battery X in order to determine the subsequent second-level protection strategy.

[0068] S4: Determine if branch one (critical fault) is detected. The severity assessment algorithm determines a problem to be "critical" if it detects any of the following: (1) U cell ≤0 V (2) dU / dt <dU / dt critical (3) T cell >T critical If any one of the above three conditions is met, the process will immediately proceed to S5.

[0069] It should be noted that the fault severity algorithm monitors the following parameters in real time to determine whether an immediate short circuit is necessary: (1) Voltage polarity determination (Ucell The absolute value of the voltage of a single cell, i.e., the potential difference between the positive and negative terminals of the cell. When U cell When the voltage is ≤0 V (first difference threshold), it must be immediately and unconditionally short-circuited. This indicates that once a battery voltage is detected to be equal to or lower than 0V, reverse polarity has occurred, and it must be immediately and unconditionally short-circuited. This is the highest priority criterion.

[0070] (2) Voltage change rate criterion (predictive judgment) When dU / dt <dU / d tcritical When the preset voltage change rate (e.g., dU / dt < -100 mV / s) is reached, short-circuit immediately. This indicates a sudden drop in voltage, foreshadowing an impending reverse polarity, and short-circuit immediately.

[0071] (3) Temperature criterion (for judging the degree of damage) When T cell >T critical (Temperature threshold) (e.g., T) cell If the temperature exceeds 85 ℃, the battery should be short-circuited immediately, and the battery status should be marked and reported as permanently damaged. This indicates extremely high local temperature, suggesting possible serious physical damage (such as film drying or sintering).

[0072] (4) Delayed short-circuit criterion (for general faults): When (0 V) is satisfied cell low (Second difference threshold) and (dU / dt>dU / dt) critical And (T) cell <T critical Under three conditions, the startup delay t delay s (time threshold, the fuel cell calibration value, such as 5 seconds). If the voltage recovers automatically within the delay, the short circuit is canceled; otherwise, the short circuit is executed. Some minor faults, such as minor flooding or reversible degradation, will recover automatically within a short time.

[0073] S5: Execute secondary protection, immediately short-circuit cell X. In the event of a severe fault, the controller generates and issues a second-priority control command with no delay or an extremely short delay (<1ms): closing the short-circuit relay (or solid-state switch or contactor) connected in parallel with battery X. This action provides a near-zero resistance bypass for the stack current, completely eliminating the possibility of current flowing back through battery X, thereby fundamentally terminating the reverse polarity corrosion reaction.

[0074] S6: Determine branch two (general fault) If the severity assessment algorithm does not detect the urgent condition in S4, when (0 V) is satisfied cell low ​​​​And (dU / dt>dU / dt) critical And (T) cell <T critical If all three conditions are met, the fault is classified as "general fault" (e.g., possibly caused by minor flooding); the process proceeds to S7.

[0075] S7: Startup Delay Short-Circuit Strategy For general faults, the controller initiates a preset delay value t. delay (e.g., 5 seconds). The purpose of this is to provide a time window for a potential, reversible fault recovery process, avoiding unnecessary short-circuiting operations.

[0076] S8: Self-recovery judgment during the observation period Before the delay timer expires, the controller continuously monitors the voltage of individual cell X.

[0077] Voltage recovery: If the voltage of individual cell X is detected to spontaneously recover to the normal range (or significantly rebound), it indicates that the fault is instantaneous and reversible. Proceed to S9.

[0078] Voltage not recovered: If the voltage of cell X remains low and shows no signs of recovery until the timer expires, it indicates that the fault is permanent, and the process enters S5 to execute the short-circuit command.

[0079] S9: Cancel the short circuit and attempt to recover. For reversible faults, the controller cancels the pending short-circuit command and further attempts to fine-tune system parameters (such as slightly increasing pressure or temperature) or execute a mild online recovery procedure (such as a low-flow purging) to help battery X fully recover.

[0080] S10: Record The status of battery X is marked (e.g., "short-circuited - permanent failure", "recovered - normal operation"), and all data of this event (trigger conditions, action commands, timestamps, key parameters) are stored in non-volatile memory to generate a "black box" record that can be used for maintenance.

[0081] S11: Update status and enter fault-tolerant operation mode. Update the system status and adjust the output power. If the battery is short-circuited, recalculate the total stack voltage and maximum allowable output power. After completing all operations, the system enters degraded fault-tolerant operation mode. The stack continues to output power, but the controller limits the maximum power to protect the remaining healthy batteries and reports the "degraded operation" status to the host computer.

[0082] In summary, this application can promptly cut off hydrogen gas and short-circuit the faulty cell when the voltage of a single cell in a hydrogen fuel cell stack is abnormal or reverse polarity occurs. The short-circuit provides a stable, extremely low impedance bypass, allowing the stack current to pass smoothly and protecting the cell from reverse polarity damage. It completely isolates the faulty cell from an electrical perspective, maintaining its physical state and reducing interference with the overall electrical environment of the system. This completely prevents the cell from being subjected to reverse current and fundamentally eliminates reverse polarity corrosion reactions.

[0083] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0084] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "N" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0085] Any process or method described in the flowchart or otherwise herein can be understood as representing a module, segment, or portion of code comprising one or N executable instructions for implementing custom logic functions or processes, and the scope of the preferred embodiments of this application includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order depending on the functions involved, as should be understood by those skilled in the art to which embodiments of this application pertain.

[0086] It should be understood that the various parts of this application can be implemented using hardware, software, firmware, or a combination thereof. In the above embodiments, the N steps or methods can be implemented using software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented using any one or more of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (FPGAs), field-programmable gate arrays (FPGAs), etc.

[0087] Those skilled in the art will understand that all or part of the steps of the methods described in the above embodiments can be implemented by a program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, it includes one or a combination of the steps of the method embodiments.

[0088] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A protection system for a hydrogen fuel cell, characterized in that, The hydrogen fuel cell stack includes multiple individual cells, and the hydrogen fuel cell protection system includes: A relay array, comprising multiple relays, wherein the two terminals of each relay are connected in parallel to the positive and negative terminals of the corresponding single battery cell, and a bypass channel is formed between the two terminals when the relay contacts are closed; A shut-off valve array, comprising multiple shut-off valves, each shut-off valve being disposed on the anode intake manifold of a corresponding single cell, controlling the opening and closing of the anode intake manifold, the anode intake manifold being connected to the hydrogen intake main of the hydrogen fuel cell; The controller is connected to the relay array and the shut-off valve array respectively. It determines the fault level of each individual battery according to the operating parameters of each individual battery, generates control commands according to the fault level, and uses the control commands to control at least one of the relay array and the shut-off valve array to close the corresponding relay and open at least one of the corresponding shut-off valves.

2. The hydrogen fuel cell protection system according to claim 1, characterized in that, The contacts of each relay in the relay array are normally open until a closing command is received from the controller.

3. The hydrogen fuel cell protection system according to claim 1, characterized in that, The resistance value of the bypass channel is less than the preset resistance value.

4. The hydrogen fuel cell protection system according to claim 1, characterized in that, The inlet end of each shut-off valve in the shut-off valve array is connected to the output end of the anode intake manifold, and the outlet end of each shut-off valve is connected to the anode chamber of the corresponding single cell.

5. A vehicle, characterized in that, include: The hydrogen fuel cell protection system as described in any one of claims 1-4.

6. A control method for a hydrogen fuel cell protection system, characterized in that, The method is applied to the controller of the hydrogen fuel cell protection system according to any one of claims 1-4, wherein the method includes the following steps: Acquire operational data from hydrogen fuel cells; Identify the operating parameters of each individual battery cell from the operating data; The fault level of each individual battery is determined based on its operating parameters. Control commands are generated based on the fault level, and at least one of the relay array and the shut-off valve array is controlled using the control commands to close the corresponding relay and open at least one of the corresponding shut-off valves.

7. The control method for the hydrogen fuel cell protection system according to claim 6, characterized in that, The process of determining the fault level of a single battery cell based on its operating parameters includes: Identify the potential difference, voltage change rate, and battery temperature of individual cells in the operating parameters; If the potential difference of the individual battery is less than or equal to a first difference threshold, or the voltage change rate is less than or equal to a preset change rate, or the battery temperature is greater than a temperature threshold, then the fault level is determined to be the first fault level. If the potential difference of the individual battery is greater than a first difference threshold and less than a second difference threshold, and the voltage change rate is greater than a preset change rate, and the temperature of the individual battery is less than or equal to a temperature threshold, then the fault level is determined to be the second fault level.

8. The control method for the hydrogen fuel cell protection system according to claim 7, characterized in that, Before determining the fault level of each individual cell based on its operating parameters, the process includes: Identify the corresponding identifier for the faulty individual battery cell; Disconnect the corresponding shut-off valve according to the identifier of the faulty individual battery.

9. The control method for the hydrogen fuel cell protection system according to claim 8, characterized in that, The generation of control commands based on the fault level includes: If the fault level is the first fault level, then a control command is generated to close the relay corresponding to the single cell. If the fault level is the second fault level, the potential difference of the individual cells within the target time period is identified, and corresponding control commands are generated based on the potential difference of the individual cells within the target time period.

10. The control method for the hydrogen fuel cell protection system according to claim 9, characterized in that, The step of generating corresponding control commands based on the potential difference of individual cells within the target time period includes: If the potential difference of a single cell does not reach the preset difference range within the target time period, a control command to close the relay corresponding to the single cell will be generated. If the potential difference is within a preset range within the target duration, the hydrogen fuel cell protection system is controlled to perform a recovery action.

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