Safety control method and device of fuel cell system, vehicle and storage medium

Abstract

The invention relates to a safety control method and device for a fuel cell system, a vehicle and a storage medium, and the method comprises the steps: calculating the voltage difference between the output voltage of a voltage converter and the input voltage of each high-voltage sub-loop if a virtual connection fault exists in the fuel cell system, and obtaining a plurality of voltage differences; and under the condition that the plurality of voltage differences are smaller than the voltage difference threshold values of the corresponding high-voltage sub-loops, calculating the maximum current limiting value of each high-voltage sub-loop according to the current temperature of each high-voltage sub-loop, and performing output power limitation on a target high-voltage sub-loop of which the current current value is greater than the maximum current limiting value in the plurality of high-voltage sub-loops. Therefore, the problem that the service life of the fuel cell system and the customer experience are influenced by high-voltage emergency power failure caused by high-voltage interlocking fault false alarm due to virtual connection of an interlocking terminal of a high-voltage interlocking loop during operation of the gas-electricity system is solved, and frequent sudden stop of the fuel cell system due to virtual connection of the high-voltage loop can be effectively avoided; and the maximum power output of the system is ensured under a safe condition.

Description

Technical Field

[0001] This application relates to the field of fuel cell technology, and in particular to a safety control method, device, vehicle, and storage medium for a fuel cell system. Background Technology

[0002] In related technologies, the detection of high-voltage interlock signals directly determines whether the high voltage of the fuel cell system should be shut down in an emergency. If the fuel cell system is in a maintenance state and not in operation, there is no problem with shutting down the high voltage in an emergency. However, if the system is in operation, and the high voltage is shut down in an emergency due to a false alarm caused by an error in the detection of the high-voltage interlock signal itself or a loose connection of the interlock terminal, it will affect the lifespan of the fuel cell system and the customer experience. Summary of the Invention

[0003] This application provides a safety control method, device, vehicle, and storage medium for a fuel cell system to solve the problem of high-voltage emergency power failure caused by false alarms due to loose connections in the high-voltage interlock circuit during operation of the fuel cell system, which affects the lifespan of the fuel cell system and the customer experience.

[0004] The first aspect of this application provides a safety control method for a fuel cell system. The fuel cell system includes a voltage converter and multiple high-voltage sub-circuits, and the voltage converter and each high-voltage sub-circuit are connected via connectors. The method includes the following steps: detecting whether there is a loose connection fault in the fuel cell system; if there is a loose connection fault in the fuel cell system, calculating the voltage difference between the output voltage of the voltage converter and the input voltage of each high-voltage sub-circuit to obtain multiple voltage differences; if all multiple voltage differences are less than the voltage difference threshold of the corresponding high-voltage sub-circuit, calculating the maximum current limit value of each high-voltage sub-circuit based on the current temperature of each high-voltage sub-circuit, and limiting the output power of the target high-voltage sub-circuit whose current current value is greater than the maximum current limit value.

[0005] Optionally, the differential voltage threshold of the high-voltage sub-circuit is calculated from the initial connection resistance value of the connector between the voltage converter and each high-voltage sub-circuit and the maximum allowable current carrying capacity corresponding to each high-voltage sub-circuit.

[0006] Optionally, after calculating the voltage difference between the output voltage of the voltage converter and the input voltage of each high-voltage sub-circuit to obtain multiple voltage differences, the method includes: if there is a target circuit in the current high-voltage circuit with a voltage difference greater than the voltage difference threshold of the corresponding high-voltage sub-circuit, then the target circuit is determined to be in a preset severe disconnection state, and the fuel cell system is powered down after the target circuit is closed.

[0007] Optionally, the step of calculating the maximum current limit value of each high-voltage sub-circuit based on the current temperature of each high-voltage sub-circuit includes: calculating the current connection resistance value of each high-voltage sub-circuit based on the preset maximum temperature in the fuel cell system and the current temperature of each high-voltage sub-circuit; and calculating the maximum current limit value of each high-voltage sub-circuit based on the current connection resistance value of each high-voltage sub-circuit and the corresponding differential pressure threshold of each high-voltage sub-circuit.

[0008] Optionally, the maximum current limit value is: I 最大限制值 =ΔV / R 新 ; R 新 = R 原 *(1+δ*(T'-20)) / (1+δ*(T 当前 -20)); Among them, I 最大限制值 R is the maximum current limit value. 新 R is the current connection resistance value of the high-voltage sub-circuit. 原 The initial connection resistance value of the high-voltage sub-circuit is given by δ, the temperature change rate of the copper busbar is given by T', and the preset maximum temperature is given by T. 当前 ΔV represents the current temperature of the high-voltage sub-circuit, and ΔV represents the differential pressure threshold corresponding to the high-voltage sub-circuit.

[0009] Optionally, detecting whether the fuel cell system has a loose connection fault includes: detecting whether there is a pulse width modulation signal of the high-voltage sub-circuit at the signal acquisition interface of the fuel cell controller; if no pulse width modulation signal of the high-voltage sub-circuit is detected at the signal acquisition interface of the fuel cell controller, then it is determined that the fuel cell system has the loose connection fault.

[0010] Optionally, after detecting whether there is a loose connection fault in the fuel cell system, the method includes: if there is no loose connection fault in the fuel cell system, controlling each high-voltage sub-circuit of the fuel cell system to continue outputting power, and performing a purge shutdown upon receiving a shutdown command.

[0011] A second aspect of this application provides a safety control device for a fuel cell system. The fuel cell system includes a voltage converter and multiple high-voltage sub-circuits, with each voltage converter and each high-voltage sub-circuit connected via a connector. The device includes: a detection module for detecting whether a loose connection fault exists in the fuel cell system; a calculation module for calculating the voltage difference between the output voltage of the voltage converter and the input voltage of each high-voltage sub-circuit to obtain multiple voltage differences if a loose connection fault exists in the fuel cell system; and a control module for calculating the maximum current limit value of each high-voltage sub-circuit based on the current temperature of each high-voltage sub-circuit when all multiple voltage differences are less than the voltage difference threshold of the corresponding high-voltage sub-circuit, and limiting the output power of the target high-voltage sub-circuit whose current current value is greater than the maximum current limit value.

[0012] Optionally, the differential voltage threshold of the high-voltage sub-circuit is calculated from the initial connection resistance value of the connector between the voltage converter and each high-voltage sub-circuit and the maximum allowable current carrying capacity corresponding to each high-voltage sub-circuit.

[0013] Optionally, after calculating the voltage difference between the output voltage of the voltage converter and the input voltage of each high-voltage sub-circuit to obtain multiple voltage differences, the control module is further configured to: if there is a target circuit in the current high-voltage circuit with a voltage difference greater than the voltage difference threshold of the corresponding high-voltage sub-circuit, determine that the target circuit is in a preset severe disconnection state, and control the fuel cell system to power down after closing the target circuit.

[0014] Optionally, the control module is further configured to: calculate the current connection resistance value of each high-voltage sub-circuit based on the preset maximum temperature in the fuel cell system and the current temperature of each high-voltage sub-circuit; and calculate the maximum current limit value of each high-voltage sub-circuit based on the current connection resistance value of each high-voltage sub-circuit and the differential pressure threshold corresponding to each high-voltage sub-circuit.

[0015] Optionally, the maximum current limit value is: I 最大限制值 =ΔV / R 新 ; R 新 = R 原 *(1+δ*(T'-20)) / (1+δ*(T 当前 -20)); Among them, I 最大限制值 R is the maximum current limit value. 新 R is the current connection resistance value of the high-voltage sub-circuit. 原 The initial connection resistance value of the high-voltage sub-circuit is given by δ, the temperature change rate of the copper busbar is given by T', and the preset maximum temperature is given by T. 当前ΔV represents the current temperature of the high-voltage sub-circuit, and ΔV represents the differential pressure threshold corresponding to the high-voltage sub-circuit.

[0016] Optionally, the detection module is further configured to: detect whether there is a pulse width modulation signal of the high-voltage sub-circuit at the signal acquisition interface of the fuel cell controller; if no pulse width modulation signal of the high-voltage sub-circuit is detected at the signal acquisition interface of the fuel cell controller, it is determined that the fuel cell system has the intermittent connection fault.

[0017] Optionally, after detecting whether there is a loose connection fault in the fuel cell system, the detection module is further configured to: if there is no loose connection fault in the fuel cell system, control each high-voltage sub-circuit of the fuel cell system to continue outputting power, and perform a purge shutdown after receiving a shutdown command.

[0018] A third aspect of this application provides a vehicle comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement a safety control method for a fuel cell system as described in the above embodiments.

[0019] A fourth aspect of this application provides a computer-readable storage medium having a computer program stored thereon, which is executed by a processor to implement a safety control method for a fuel cell system as described in the above embodiments.

[0020] In the above implementation, the presence of a loose connection fault in the fuel cell system is detected. If a loose connection fault exists, the voltage difference between the output voltage of the voltage converter and the input voltage of each high-voltage sub-circuit is calculated to obtain multiple voltage differences. If all multiple voltage differences are less than the voltage difference threshold of the corresponding high-voltage sub-circuit, the maximum current limit value of each high-voltage sub-circuit is calculated based on the current temperature of each high-voltage sub-circuit. Output power is limited for the target high-voltage sub-circuit whose current current value exceeds the maximum current limit value. This solves the problem of false alarms due to high-voltage interlock faults caused by loose connections in the high-voltage interlock circuit during fuel cell operation, leading to high-voltage emergency power outages that affect the lifespan of the fuel cell system and customer experience. It effectively avoids frequent emergency shutdowns of the fuel cell system due to loose connections in the high-voltage circuit, ensuring maximum system power output while maintaining safety.

[0021] 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

[0022] 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 flowchart of a safety control method for a fuel cell system according to an embodiment of this application; Figure 2 This is a schematic diagram of a high-voltage interlock circuit according to an embodiment of this application; Figure 3 This is a schematic diagram of a high-voltage temperature monitoring design according to an embodiment of this application; Figure 4 This is a flowchart of a safety control method for a fuel cell system according to an embodiment of this application; Figure 5 This is an example diagram of a safety control device for a fuel cell system according to an embodiment of this application; Figure 6 This is a schematic diagram of a vehicle structure according to an embodiment of this application. Detailed Implementation

[0023] 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.

[0024] The following description, with reference to the accompanying drawings, outlines a safety control method, apparatus, vehicle, and storage medium for a fuel cell system according to embodiments of this application. Addressing the issue mentioned in the background art where false alarms of high-voltage interlock faults caused by loose connections in the high-voltage interlock circuit lead to emergency power outages, impacting the lifespan of the fuel cell system and customer experience, this application provides a safety control method for a fuel cell system. In this method, the presence of a loose connection fault in the fuel cell system is detected. If a loose connection fault exists, the voltage difference between the output voltage of the voltage converter and the input voltage of each high-voltage sub-circuit is calculated to obtain multiple voltage differences. If all multiple voltage differences are less than the voltage difference threshold of the corresponding high-voltage sub-circuit, the maximum current limit value of each high-voltage sub-circuit is calculated based on the current temperature of each high-voltage sub-circuit. Output power is limited for target high-voltage sub-circuit whose current current value exceeds the maximum current limit value. This solves the problem of false alarms of high-voltage interlock faults caused by loose connections in the high-voltage interlock circuit leading to emergency power outages, impacting the lifespan of the fuel cell system and customer experience. It effectively avoids frequent emergency shutdowns of the fuel cell system due to loose connections in the high-voltage circuit, ensuring maximum system power output while maintaining safety.

[0025] A typical high-pressure safety system for a hydrogen fuel cell engine includes a fuel cell controller, a manual maintenance button connected to the fuel cell controller, and a fuel cell high-pressure interlock system connecting the manual maintenance button and the fuel cell controller. The fuel cell high-pressure interlock system includes a fuel cell stack connected to the manual maintenance button, a fuel cell boost DC-DC converter connected to the fuel cell stack, and fuel cell auxiliary equipment connected to the fuel cell boost DC-DC converter. The fuel cell auxiliary equipment is connected to the fuel cell controller.

[0026] In existing solutions, the detection of the high-voltage interlock signal directly determines whether the high voltage of the fuel cell system should be cut off in an emergency. If the fuel cell system is in a maintenance state and not in operation, there is no problem with cutting off the high voltage in an emergency. However, if it is in operation, a false alarm caused by a high-voltage interlock fault due to an error in the detection of the high-voltage interlock signal itself or a loose connection of the interlock terminal will affect the lifespan of the fuel cell system and the customer experience. To solve the above problems, this application proposes a safety control method for fuel cell systems.

[0027] Specifically, Figure 1 This is a flowchart illustrating a safety control method for a fuel cell system provided in an embodiment of this application.

[0028] like Figure 1 As shown, the safety control method for this fuel cell system includes the following steps: The fuel cell system includes a voltage converter and multiple high-voltage sub-circuits, with the voltage converter and each high-voltage sub-circuit connected via connectors.

[0029] In step S101, the presence of a loose connection fault in the fuel cell system is detected.

[0030] Optionally, in some embodiments, detecting whether a loose connection fault exists in the fuel cell system includes: detecting whether a pulse width modulation signal of the high-voltage sub-circuit exists at the signal acquisition interface of the fuel cell controller; if no pulse width modulation signal of the high-voltage sub-circuit is detected at the signal acquisition interface of the fuel cell controller, it is determined that a loose connection fault exists in the fuel cell system.

[0031] The design of high-voltage interlock circuits, such as Figure 2As shown: The FCU's signal input Sig_Push interface is connected to the high-voltage interlock signal terminal on the XT2 hydrogen circulation pump connector via a wire. The high-voltage interlock terminal on the XT2 connector is connected to the high-voltage interlock terminal on the high-pressure water pump XT4 connector via a wire. The high-voltage interlock terminal on the XT4 connector is connected to the high-voltage interlock terminal on the PTC heater XT6 connector via a wire. The high-voltage interlock terminal on the XT6 connector is then connected to the high-voltage interlock terminal on the DC-DC converter's XT connector via a wire. The high-voltage interlock terminal on the XT connector is then connected to the Sig_Collect signal acquisition interface on the FCU via a wire.

[0032] After the fuel cell system is powered on, the FCU will drive the output of a pulse width modulation (PWM) signal with a fixed frequency and fixed duty cycle on the Sig_Push. At the same time, the FCU will detect the PWM signal on the signal acquisition interface Sig_Collect. If the intermediate high-voltage interlock terminal is disconnected, the PWM signal will not be detected on the Sig_Collect. At this time, a high-voltage interlock fault will be reported, indicating that there is a loose connection fault in the fuel cell system.

[0033] In step S102, if there is a loose connection fault in the fuel cell system, the voltage difference between the output voltage of the voltage converter and the input voltage of each high-voltage sub-circuit is calculated to obtain multiple voltage differences.

[0034] Specifically, the design schematic diagram for high-voltage monitoring is as follows: Figure 3 As shown, the high-voltage interlock terminal of connector XT2 of the hydrogen circulation pump is connected to the high-voltage interlock terminal of connector XT1 of the DC-DC converter, the high-voltage interlock terminal of connector XT4 of the high-pressure water pump is connected to the high-voltage interlock terminal of connector XT2 of the DC-DC converter, and the high-voltage interlock terminal of connector XT6 of the PTC heater is connected to the high-voltage interlock terminal of connector XT3 of the DC-DC converter. Temperature acquisition point T1 is set on the internal copper busbar connecting the high-voltage circuit of the circulation pump. Similarly, T2 and T3 are temperature acquisition points for the water pump and PTC circuit.

[0035] If a loose connection fault exists in the fuel cell system, the voltage difference between the output voltage of the voltage converter and the input voltage of each high-voltage sub-circuit is calculated to obtain multiple voltage differences: Obtain the voltage values ​​of each high-voltage component on the high-voltage system. U0 is the high-voltage output of the DC-DC converter, U1 is the high-voltage input of the hydrogen circulation pump, U2 is the high-voltage input of the high-pressure water pump, and U3 is the high-voltage input of the PTC heater. The voltage difference between the output voltage of the voltage converter and the input voltage of the hydrogen circulation pump circuit is: ΔV1'=U0-U1; The voltage difference between the output voltage of the voltage converter and the input voltage of the high-pressure water pump circuit is: ΔV2'=U0-U2; The voltage difference between the output voltage of the voltage converter and the input voltage of the PTC heater circuit is: ΔV3'=U0-U3.

[0036] Optionally, in some embodiments, after calculating the voltage difference between the output voltage of the voltage converter and the input voltage of each high-voltage sub-circuit to obtain multiple voltage differences, the method includes: if there is a target circuit in the current high-voltage circuit with a voltage difference greater than the voltage difference threshold of the corresponding high-voltage sub-circuit, then the target circuit is determined to be in a preset severe disconnection state, and the fuel cell system is powered down after the target circuit is closed.

[0037] In some embodiments, the differential voltage threshold of the high-voltage sub-circuit is calculated from the initial connection resistance value of the connector between the voltage converter and each high-voltage sub-circuit and the maximum allowable current carrying capacity corresponding to each high-voltage sub-circuit.

[0038] The specific calculation method for the differential pressure threshold of the high-voltage sub-circuit is as follows: Determine the connection resistance R1 between the DC-DC converter and the hydrogen circulation pump, and the maximum allowable current I1 in this connection circuit. R1 consists of the connection resistance of connector XT1 and connector XT2, the wire resistance between connector XT1 and connector XT2, and the resistance of the internal connection wires of the DC-DC converter.

[0039] The maximum permissible voltage drop (i.e., the voltage difference threshold between the DC-DC converter and the high-pressure circulating pump circuit) is determined based on R1 and the maximum current I1: ΔV1 = I1 * R1; The same method can be used to determine the maximum allowable voltage drop (i.e., the voltage difference threshold between the DC and the high-pressure water pump circuit): ΔV2=I2*R2, where R2 is the connection resistance between the DC and the high-pressure water pump, and I2 is the maximum allowable current carrying capacity in the connection circuit between the DC and the high-pressure water pump. Similarly, the maximum permissible voltage drop (i.e., the voltage difference threshold of the DC-DC and PTC heater circuit) ΔV3 is confirmed in the same way as R3, where R3 is the connection resistance between the DC-DC and PTC heaters, and I3 is the maximum permissible current carrying capacity of the DC-DC and PTC heater connection circuit.

[0040] If there is a target circuit in the current high-voltage circuit whose pressure difference is greater than the pressure difference threshold of the corresponding high-voltage sub-circuit, the target circuit is determined to be in a preset severe disconnection state, and the fuel cell system is powered down after the target circuit is closed. For example, if ΔV1'>ΔV1, the target circuit is the hydrogen circulation pump circuit, indicating that the hydrogen circulation pump circuit is in a preset severe disconnection state, and the fuel cell system is powered down after the hydrogen circulation pump circuit is closed.

[0041] In step S103, when multiple pressure differences are all less than the pressure difference threshold of the corresponding high-voltage sub-circuit, the maximum current limit value of each high-voltage sub-circuit is calculated based on the current temperature of each high-voltage sub-circuit, and the output power of the target high-voltage sub-circuit whose current current value is greater than the maximum current limit value is limited.

[0042] Optionally, in some embodiments, the maximum current limit value of each high-voltage sub-circuit is calculated based on the current temperature of each high-voltage sub-circuit, including: calculating the current connection resistance value of each high-voltage sub-circuit based on the preset maximum temperature in the fuel cell system and the current temperature of each high-voltage sub-circuit; and calculating the maximum current limit value of each high-voltage sub-circuit based on the current connection resistance value of each high-voltage sub-circuit and the differential pressure threshold corresponding to each high-voltage sub-circuit.

[0043] Optionally, in some embodiments, the maximum current limit value is: I 最大限制值 =ΔV / R 新 ; R 新 = R 原 *(1+δ*(T'-20)) / (1+δ*(T 当前 -20)); Among them, I 最大限制值 R is the maximum current limit value. 新 R is the current connection resistance value of the high-voltage sub-circuit. 原 The initial connection resistance value of the high-voltage sub-circuit is given by δ, the temperature change rate of the copper busbar is given by T', and the preset maximum temperature is given by T. 当前 ΔV represents the current temperature of the high-voltage sub-circuit, and ΔV represents the differential pressure threshold corresponding to the high-voltage sub-circuit.

[0044] When multiple differential pressures are all less than the differential pressure threshold of the corresponding high-voltage sub-circuit, the maximum current limit value of each high-voltage sub-circuit is calculated based on the current temperature of each high-voltage sub-circuit. Specifically: Obtain the current values ​​of the circulating pump, water pump, and PTC, respectively, I. 11 I 22 I 33 Based on the feedback current and measured voltage difference from each component, calculate the initial connection resistance R of the actual circulating pump circuit at the current temperature T1. 11 =(U0-U1) / I 11 ; Similarly, the initial connection resistance R of the actual water pump circuit at the current temperature T2 can be calculated. 22 =(U0-U2) / I 22 And calculate the initial connection resistance R of the actual PTC circuit at the current temperature T3.33 =(U0-U3) / I 33 .

[0045] Further analysis of the copper busbar and surrounding environment reveals the maximum temperature limit for the internal copper busbar and connecting circuit to be T' (i.e., the preset maximum temperature). Based on this maximum temperature limit, the current connection resistance value of the circulating pump connecting circuit is corrected to: R. 1t = R 11 *(1+δ*(T'-20)) / (1+δ*(T1-20)),the maximum current limit value of the circulating pump circuit is: I 1t =ΔV3 / R 1t .

[0046] Similarly, the current connection resistance value of the water pump connection circuit is: R 2t = R 22 *(1+δ*(T'-20)) / (1+δ*(T2-20)),the maximum current limit value of the water pump circuit I 2t =ΔV3 / R2.

[0047] Similarly, the current connection resistance value of the PTC connection loop is: R 3t = R 33 *(1+δ*(T'-20)) / (1+δ*(T3-20)),the maximum current limit value I of the PTC circuit is 3t =ΔV3 / R 3t .

[0048] Furthermore, based on the current current value I of the circulating pump circuit... 11 and maximum current limit value I 1t The current value I of the water pump circuit 22 and maximum current limit value I 2t The current value I of the PTC circuit 33 and maximum current limit value I 3t Identify the target high-voltage sub-circuit whose current current value exceeds the maximum current limit, and limit its output power based on the maximum current limit. This prevents frequent shutdowns caused by loose connections in the high-voltage circuit. For example, if the current current value I of the circulating pump circuit... 11 Greater than the maximum current limit value I 1t If the target high voltage sub-circuit is the circulating pump circuit, then the circulating pump is controlled to limit the output power according to the maximum current limit value.

[0049] Optionally, in some embodiments, after detecting whether there is a loose connection fault in the fuel cell system, the method includes: if there is no loose connection fault in the fuel cell system, controlling each high-voltage sub-circuit of the fuel cell system to continue outputting power, and performing a purge shutdown upon receiving a shutdown command.

[0050] It should be understood that if there is no loose connection fault in the fuel cell system, the fuel cell system will respond normally to the vehicle's power demand, and each high-voltage sub-circuit of the fuel cell system will continue to output power. If the fuel cell system receives a shutdown command, the fuel cell system will perform a purge shutdown.

[0051] To enable those skilled in the art to further understand the safety control method of the fuel cell system according to the embodiments of this application, the following detailed description is provided in conjunction with specific embodiments, such as... Figure 4 As shown.

[0052] When the fuel cell system is powered on at high voltage, it enters the operating state and outputs power according to the power requirements of the vehicle. The FCU detects the high voltage interlock signal and simultaneously obtains the voltage parameters of each high voltage sub-circuit. The FCU determines whether the high-voltage interlock signal is normal. If it is normal, the fuel cell system responds normally to the power demand of the vehicle and enters the purge shutdown when it receives the shutdown command. If abnormal, calculate the pressure difference ΔV1' between DC-DC and the hydrogen circulation pump, the pressure difference ΔV2' between DC-DC and the high-pressure water pump, and the pressure difference ΔV3' between DC-DC and PTC, and compare them with the corresponding pressure difference thresholds; Determine whether ΔV1' is less than or equal to ΔV1, whether ΔV2' is less than or equal to ΔV2, and whether ΔV3' is less than or equal to ΔV3; If so, obtain the current current values ​​of the circulating pump, water pump, and PTC, and calculate the maximum current limit values ​​of the circulating pump, water pump, and PTC. If the current current values ​​of the circulating pump, water pump, and PTC do not exceed the corresponding maximum current limit values, no power limitation is applied. If any of the current current values ​​of the circulating pump, water pump, and PTC exceeds the maximum current limit value, the power output of the high-voltage component is limited according to the maximum current limit value, and a purge shutdown is initiated upon receiving a shutdown command. If ΔV1' is greater than ΔV1, or ΔV2' is greater than ΔV2, or ΔV3' is greater than ΔV3, then the fuel cell system is controlled to enter the shutdown state.

[0053] In summary, the beneficial effects of this application are as follows: (1) Under the condition of high voltage interlock fault triggering, the voltage drop of the high voltage interlock detection circuit is calculated by using the voltage detection of each relevant high voltage component inside the fuel cell system, and the interlock circuit is further confirmed to determine whether the fuel cell should be stopped urgently. This can effectively avoid the problem of frequent emergency stops of the fuel cell system caused by the high voltage interlock terminal loose connection and the high voltage circuit loose connection. (2) In the event of a high-voltage interlock fault, the power of the fuel cell system is limited by monitoring the temperature of the copper busbar connection circuit and calculating the real-time resistance of the connection circuit, and calculating the maximum current limit value of each high-voltage component at the highest allowable temperature according to the temperature correction. Under the condition of ensuring safety, the maximum power output of the system in this state can be guaranteed.

[0054] Next, the safety control device for a fuel cell system according to an embodiment of this application is described with reference to the accompanying drawings.

[0055] Figure 5 This is a block diagram of the safety control device of the fuel cell system according to an embodiment of this application.

[0056] like Figure 5 As shown, the safety control device 10 of the fuel cell system includes a detection module 100, a calculation module 200, and a control module 300. The fuel cell system includes a voltage converter and multiple high-voltage sub-circuits, with the voltage converter and each high-voltage sub-circuit connected via connectors. The detection module 100 is used to detect whether there is a loose connection fault in the fuel cell system; the calculation module 200 is used to calculate the voltage difference between the output voltage of the voltage converter and the input voltage of each high-voltage sub-circuit to obtain multiple voltage differences if there is a loose connection fault in the fuel cell system; the control module 300 is used to calculate the maximum current limit value of each high-voltage sub-circuit based on the current temperature of each high-voltage sub-circuit when multiple voltage differences are all less than the voltage difference threshold of the corresponding high-voltage sub-circuit, and to limit the output power of the target high-voltage sub-circuit whose current current value is greater than the maximum current limit value among the multiple high-voltage sub-circuit.

[0057] Optionally, in some embodiments, the differential voltage threshold of the high-voltage sub-circuit is calculated from the initial connection resistance value of the connector between the voltage converter and each high-voltage sub-circuit and the maximum allowable current carrying capacity corresponding to each high-voltage sub-circuit.

[0058] Optionally, in some embodiments, after calculating the voltage difference between the output voltage of the voltage converter and the input voltage of each high-voltage sub-circuit to obtain multiple voltage differences, the control module 300 is further configured to: if there is a target circuit in the current high-voltage circuit with a voltage difference greater than the voltage difference threshold of the corresponding high-voltage sub-circuit, determine that the target circuit is in a preset severe disconnection state, and control the fuel cell system to power down after closing the target circuit.

[0059] Optionally, in some embodiments, the control module 300 is further configured to: calculate the current connection resistance value of each high-voltage sub-circuit based on the preset maximum temperature in the fuel cell system and the current temperature of each high-voltage sub-circuit; and calculate the maximum current limit value of each high-voltage sub-circuit based on the current connection resistance value of each high-voltage sub-circuit and the differential pressure threshold corresponding to each high-voltage sub-circuit.

[0060] Optionally, in some embodiments, the maximum current limit value is: I 最大限制值 =ΔV / R 新 ; R 新 = R 原 *(1+δ*(T'-20)) / (1+δ*(T 当前 -20)); Among them, I 最大限制值 R is the maximum current limit value. 新 R is the current connection resistance value of the high-voltage sub-circuit. 原 The initial connection resistance value of the high-voltage sub-circuit is given by δ, the temperature change rate of the copper busbar is given by T', and the preset maximum temperature is given by T. 当前 ΔV represents the current temperature of the high-voltage sub-circuit, and ΔV represents the differential pressure threshold corresponding to the high-voltage sub-circuit.

[0061] Optionally, in some embodiments, the detection module 100 is further configured to: detect whether there is a pulse width modulation signal of the high voltage sub-circuit at the signal acquisition interface of the fuel cell controller; if no pulse width modulation signal of the high voltage sub-circuit is detected at the signal acquisition interface of the fuel cell controller, it is determined that there is a loose connection fault in the fuel cell system.

[0062] Optionally, in some embodiments, after detecting whether there is a loose connection fault in the fuel cell system, the detection module 100 is further configured to: if there is no loose connection fault in the fuel cell system, control each high-voltage sub-circuit of the fuel cell system to continue outputting power, and perform a purge shutdown after receiving a shutdown command.

[0063] It should be noted that the foregoing explanation of the safety control method embodiment for the fuel cell system also applies to the safety control device of the fuel cell system in this embodiment, and will not be repeated here.

[0064] According to the safety control device for a fuel cell system proposed in this application, the device detects whether a loose connection fault exists in the fuel cell system. If a loose connection fault exists, the device calculates the voltage difference between the output voltage of the voltage converter and the input voltage of each high-voltage sub-circuit to obtain multiple voltage differences. If all multiple voltage differences are less than the voltage difference threshold of the corresponding high-voltage sub-circuit, the device calculates the maximum current limit value of each high-voltage sub-circuit based on the current temperature of each high-voltage sub-circuit, and limits the output power of the target high-voltage sub-circuit whose current current value is greater than the maximum current limit value. This solves the problem of false alarms caused by high-voltage interlock faults due to loose connections in the interlock terminals of the high-voltage interlock circuit during fuel cell operation, which leads to high-voltage emergency power loss, affecting the lifespan of the fuel cell system and customer experience. It effectively avoids frequent emergency shutdowns of the fuel cell system due to loose connections in the high-voltage circuit, ensuring the maximum power output of the system while guaranteeing safety.

[0065] Figure 6 A schematic diagram of the structure of a vehicle provided in an embodiment of this application. The vehicle may include: The memory 601, the processor 602, and the computer program stored on the memory 601 and capable of running on the processor 602.

[0066] When the processor 602 executes the program, it implements the safety control method for the fuel cell system provided in the above embodiments.

[0067] Furthermore, the vehicle also includes: Communication interface 603 is used for communication between memory 601 and processor 602.

[0068] The memory 601 is used to store computer programs that can run on the processor 602.

[0069] The memory 601 may include high-speed RAM memory, and may also include non-volatile memory, such as at least one disk storage device.

[0070] If the memory 601, processor 602, and communication interface 603 are implemented independently, then the communication interface 603, memory 601, and processor 602 can be interconnected via a bus to complete communication between them. The bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, or an Extended Industry Standard Architecture (EISA) bus, etc. The bus can be divided into address bus, data bus, control bus, etc. For ease of representation, Figure 6 The bus is represented by a single thick line, but this does not mean that there is only one bus or one type of bus.

[0071] Optionally, in a specific implementation, if the memory 601, processor 602, and communication interface 603 are integrated on a single chip, then the memory 601, processor 602, and communication interface 603 can communicate with each other through an internal interface.

[0072] The processor 602 may be a central processing unit (CPU), an application specific integrated circuit (ASIC), or one or more integrated circuits configured to implement the embodiments of this application.

[0073] This application also provides a computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements the above-described safety control method for a fuel cell system.

[0074] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is 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.

[0075] 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.

[0076] 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 more 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.

[0077] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a ordered list of executable instructions for implementing logical functions, and can be embodied in any computer-readable storage medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (such as a computer-based system, a processor-included system, or other system that can fetch and execute instructions from, an instruction execution system, apparatus, or device). For the purposes of this specification, "computer-readable storage medium" can be any means that can contain, store, communicate, propagate, or transmit programs for use by, or in conjunction with, an instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of computer-readable storage media include: an electrical connection having one or more wires (electronic device), a portable computer disk drive (magnetic device), random access memory (RAM), read-only memory (ROM), erasable and editable read-only memory (EPROM or flash memory), fiber optic devices, and portable optical disc read-only memory (CDROM). Alternatively, the computer-readable storage medium could be paper or other suitable media on which the program can be printed, since the program can be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, interpreting, or otherwise processing as necessary, and then stored in a computer memory.

[0078] 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 a combination 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 (PGAs), field-programmable gate arrays (FPGAs), etc.

[0079] 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.

[0080] Furthermore, the functional units in the various embodiments of this application can be integrated into a processing module, or each unit can exist physically separately, or two or more units can be integrated into a module. The integrated module can be implemented in hardware or as a software functional module. If the integrated module is implemented as a software functional module and sold or used as an independent product, it can also be stored in a computer-readable storage medium.

[0081] The computer-readable storage medium mentioned above may be a read-only memory, a magnetic disk, or an optical disk, etc. 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 safety control method for a fuel cell system, characterized in that, The fuel cell system includes a voltage converter and multiple high-voltage sub-circuits, wherein the voltage converter and each high-voltage sub-circuit are connected via connectors, and the method includes the following steps: Detect whether the fuel cell system has a loose connection fault; If the fuel cell system has a loose connection fault, the voltage difference between the output voltage of the voltage converter and the input voltage of each high-voltage sub-circuit is calculated to obtain multiple voltage differences; When all the differential pressures are less than the differential pressure threshold of the corresponding high-voltage sub-circuit, the maximum current limit value of each high-voltage sub-circuit is calculated based on the current temperature of each high-voltage sub-circuit, and the output power of the target high-voltage sub-circuit whose current current value is greater than the maximum current limit value is limited.

2. The method according to claim 1, characterized in that, The differential voltage threshold of the high-voltage sub-circuit is calculated from the initial connection resistance value of the connector between the voltage converter and each high-voltage sub-circuit and the maximum allowable current carrying capacity of each high-voltage sub-circuit.

3. The method according to claim 1, characterized in that, After calculating the voltage difference between the voltage converter output voltage and the input voltage of each high-voltage sub-circuit to obtain multiple voltage differences, including: If there is a target circuit in the current high-voltage circuit whose differential pressure is greater than the differential pressure threshold of the corresponding high-voltage sub-circuit, the target circuit is determined to be in a preset severe disconnection state, and the fuel cell system is powered down after the target circuit is closed.

4. The method according to claim 1, characterized in that, The calculation of the maximum current limit value for each high-voltage sub-circuit based on the current temperature of each high-voltage sub-circuit includes: The current connection resistance value of each high-voltage sub-circuit is calculated based on the preset maximum temperature in the fuel cell system and the current temperature of each high-voltage sub-circuit. The maximum current limit value of each high-voltage sub-circuit is calculated based on the current connection resistance value of each high-voltage sub-circuit and the corresponding differential voltage threshold value.

5. The method according to claim 4, characterized in that, The maximum current limit value is: I 最大限制值 =ΔV / R 新 ; R 新 = R 原 *(1+δ*(T'-20)) / (1+δ*(T 当前 -20); Among them, I 最大限制值 R is the maximum current limit value. 新 R is the current connection resistance value of the high-voltage sub-circuit. 原 The initial connection resistance value of the high-voltage sub-circuit is given by δ, the temperature change rate of the copper busbar is given by T', and the preset maximum temperature is given by T. 当前 ΔV represents the current temperature of the high-voltage sub-circuit, and ΔV represents the differential pressure threshold corresponding to the high-voltage sub-circuit.

6. The method according to claim 1, characterized in that, The detection of whether the fuel cell system has a loose connection fault includes: Check if there is a pulse width modulation signal in the high-voltage sub-circuit at the signal acquisition interface of the fuel cell controller; If the pulse width modulation signal of the high-voltage sub-circuit is not detected at the signal acquisition interface of the fuel cell controller, the fuel cell system is determined to have the aforementioned intermittent connection fault.

7. The method according to claim 6, characterized in that, After detecting whether there is a loose connection fault in the fuel cell system, the process includes: If the fuel cell system does not have the aforementioned loose connection fault, then each high-voltage sub-circuit of the fuel cell system is controlled to continue outputting power, and a purge shutdown is performed upon receiving a shutdown command.

8. A safety control device for a fuel cell system, characterized in that, The fuel cell system includes a voltage converter and multiple high-voltage sub-circuits, wherein the voltage converter and each high-voltage sub-circuit are connected via connectors, and the device includes: The detection module is used to detect whether there is a loose connection fault in the fuel cell system; The calculation module is used to calculate the voltage difference between the output voltage of the voltage converter and the input voltage of each high-voltage sub-circuit to obtain multiple voltage differences if there is a loose connection fault in the fuel cell system. The control module is used to calculate the maximum current limit value of each high-voltage sub-circuit based on the current temperature of each high-voltage sub-circuit when the multiple pressure differences are all less than the pressure difference threshold of the corresponding high-voltage sub-circuit, and to limit the output power of the target high-voltage sub-circuit whose current current value is greater than the maximum current limit value among the multiple high-voltage sub-circuit.

9. A vehicle, characterized in that, It includes a memory, a processor, and a computer program stored in the memory and executable on the processor, the processor executing the program to implement the safety control method for the fuel cell system as described in any one of claims 1-7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, The program is executed by the processor to implement the safety control method for the fuel cell system as described in any one of claims 1-7.

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