Fuel cell system and vehicle
By adding isolation devices to the fuel cell system and controlling their conduction when the conductivity is below a preset value, the problem of reduced insulation in fuel cell vehicles is solved, thereby improving safety performance and reducing costs, and ensuring normal vehicle startup.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-14
- Publication Date
- 2026-03-13
AI Technical Summary
In existing fuel cell vehicles, the increased conductivity of the coolant after prolonged storage leads to reduced insulation and causes insulation failures. Existing solutions suffer from either decreased safety performance or increased costs.
By adding first and second isolation devices to the fuel cell system, the positive and negative electrodes of the fuel cell are connected to the positive and negative input electrodes of the power supply module, respectively. The controller controls the isolation devices to conduct when the conductivity is lower than a preset value, thereby achieving physical isolation between the fuel cell and the power supply module.
It improves the insulation performance of the fuel cell system, optimizes safety performance, reduces vehicle costs, and ensures that the vehicle can start normally.
Smart Images
Figure CN223993260U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of fuel cells, and in particular to a fuel cell system and a vehicle. Background Technology
[0002] A fuel cell is a power generation device that converts the chemical energy produced by the oxidation of hydrogen into electrical energy. Since the hydrogen and oxygen required for the fuel cell reaction need to be continuously supplied from an external source under certain conditions, and the heat generated by the reaction needs to be cooled, a fuel cell system consists of a hydrogen supply component, an oxygen supply component, a cooling component, an electrical component, and the fuel cell itself.
[0003] In recent years, fuel cell systems have been commercially tested in various fields, especially the automotive industry. Because the reaction product of fuel cell systems is pure water, which is very environmentally friendly, their commercial operation in vehicles has received strong support. Fuel cell vehicles are generally composed of an electric-electric hybrid system, where the fuel cell system generates electricity and a lithium battery acts as a parallel power source to provide electricity to the electric motor to drive the vehicle. The vehicle voltage is classified as a Class B high-voltage system. In high-voltage systems, to ensure the safety of vehicle components and personnel, the vehicle must be maintained in a high insulation state.
[0004] During vehicle operation, an insulation monitoring module continuously monitors the vehicle's insulation levels. When the insulation is low, the vehicle needs to take appropriate measures. Pure electric vehicles consist of multiple high-voltage components coupled together. If the insulation value of one high-voltage component or a single point is low, it will cause the entire vehicle's insulation system to detect an insulation fault. Generally, low insulation in pure electric vehicles is primarily caused by a fault in the high-voltage section of the high-voltage components.
[0005] In fuel cell systems, the stack needs to be cooled, and the coolant directly contacts the bipolar plates of the stack, meaning the coolant is directly connected to the high-voltage section. Therefore, an increase in the conductivity of the coolant can lead to a decrease in the insulation of the fuel cell, resulting in lower insulation in fuel cell vehicles.
[0006] Specifically, the cooling components of a fuel cell system include: coolant, conductivity meter, water pump, radiator fan, connecting pipes, deionizer, and thermostat. Among these, the cooling fins and connecting metal parts of the radiator fan will release ions when in prolonged contact with the coolant, especially the radiator fan fins. Therefore, the conductivity of the coolant will increase after a fuel cell vehicle has been idle for an extended period. If the fuel cell system does not take measures to reduce the conductivity, the vehicle will report a low insulation fault, preventing it from starting and operating.
[0007] To address the issue of low insulation in existing fuel cell vehicles, there are generally two methods:
[0008] First, lowering the vehicle's insulation fault threshold will reduce the vehicle's safety performance, making it impossible to correctly diagnose problems that actually occur in other high-voltage components.
[0009] Second, adding insulation monitoring modules to both the fuel cell and the vehicle end, monitoring the insulation value at the fuel cell end before startup, and stopping the insulation module at the fuel cell end after startup is completed, increases the system cost and control complexity. Utility Model Content
[0010] The technical problem to be solved by this utility model is to overcome the defects of existing methods for solving vehicle insulation problems, which result in decreased safety performance and increased cost, and to provide a fuel cell system and vehicle.
[0011] The present invention solves the above-mentioned technical problems through the following technical solution:
[0012] In a first aspect, a fuel cell system is provided, the fuel cell system including a fuel cell, a power supply module, a first isolation device, a second isolation device, a controller, and a fuel cell cooling system, the fuel cell cooling system including a conductivity meter for detecting the conductivity of the coolant;
[0013] One end of the first isolation device is connected to the positive terminal of the fuel cell, and the other end of the first isolation device is connected to the input positive terminal of the power supply module;
[0014] One end of the second isolation device is connected to the negative electrode of the fuel cell, and the other end of the second isolation device is connected to the input negative electrode of the power supply module;
[0015] The controller is connected to the control terminal of the first isolation device and the control terminal of the second isolation device, respectively.
[0016] The conductivity meter is electrically connected to the controller; the controller is used to receive the conductivity detected by the conductivity meter, and control the first isolation device and the second isolation device to conduct when the conductivity is less than a first preset value; the power supply module is used to supply power to external components.
[0017] Optionally, both the first isolation device and the second isolation device are normally open relays;
[0018] One end of the first isolation device is the common terminal or normally open contact of a normally open relay, and the other end of the first isolation device is the normally open contact or common terminal of a normally open relay.
[0019] One end of the second isolation device is the common terminal or normally open contact of a normally open relay, and the other end of the second isolation device is the normally open contact or common terminal of a normally open relay.
[0020] Optionally, the fuel cell system further includes a relay box, wherein both the first isolation device and the second isolation device are located inside the relay box.
[0021] Optionally, the power supply module includes a DC-DC converter and a power distribution unit;
[0022] The positive input terminal of the DC-DC converter is connected to the other end of the first isolation device, and the negative input terminal of the DC-DC converter is connected to the other end of the second isolation device.
[0023] The output terminal of the DC-DC converter is connected to the input terminal of the power distribution unit;
[0024] The power distribution unit is used to distribute the voltage output by the DC-DC converter to the external components.
[0025] Optionally, the positive input terminal of the power supply module is also connected to the positive terminal of the lithium battery, and the negative input terminal of the power supply module is also connected to the negative terminal of the lithium battery;
[0026] The lithium battery is used to power the fuel cell cooling system and the controller via the power supply module.
[0027] Optionally, the fuel cell cooling system further includes a water pump, a deionizer, a fan, and a three-way valve;
[0028] One end of the conductivity meter is connected to the output end of the water pump and the input end of the deionizer, and the other end of the conductivity meter is connected to the input end of the fuel cell.
[0029] The output end of the water pump is connected to the input end of the fuel cell and the input end of the deionizer, respectively. The input end of the water pump is connected to one end of the fan and the first port of the three-way valve, respectively.
[0030] The output end of the fuel cell is connected to the second port of the three-way valve, and the other end of the fan is connected to the third port of the three-way valve.
[0031] The controller is electrically connected to the three-way valve and the water pump respectively; the controller is used to control the operation of the water pump when the conductivity is greater than or equal to the preset value.
[0032] Optionally, the fuel cell cooling system further includes a temperature sensor for detecting the temperature of the coolant; the temperature sensor is electrically connected to the controller.
[0033] The controller is also configured to receive the temperature detected by the temperature sensor, and control the first interface to be connected to the second interface when the temperature is less than a second preset value; and control the third interface to be connected to the second interface when the temperature is greater than or equal to the second preset value.
[0034] In a second aspect, a vehicle is provided, the vehicle including the fuel cell system as described in the first aspect.
[0035] Optionally, the vehicle further includes an external component of the fuel cell system, which is connected to the output of the power supply module in the fuel cell system.
[0036] Optionally, the vehicle further includes a lithium battery, the positive terminal of which is connected to the positive input terminal of the power supply module, and the negative terminal of which is connected to the negative input terminal of the power supply module.
[0037] Based on common knowledge in the field, the above-mentioned preferred conditions can be combined arbitrarily to obtain various preferred embodiments of this utility model.
[0038] The significant advantages of this invention are as follows: To address the issues of decreased vehicle safety performance and increased costs in existing technologies, physical isolation between the fuel cell and the power supply module is achieved by adding isolation devices. Specifically, one end of the first isolation device is connected to the positive terminal of the fuel cell, and the other end is connected to the positive input terminal of the power supply module; one end of the second isolation device is connected to the negative terminal of the fuel cell, and the other end is connected to the negative input terminal of the power supply module; when the controller receives a conductivity value lower than a first preset value, it controls the first and second isolation devices to conduct, thereby improving the insulation performance of the fuel cell system, optimizing the safety performance of the fuel cell system, and reducing vehicle costs. Attached Figure Description
[0039] Figure 1 This is a schematic diagram of a fuel cell system provided in Embodiment 1 of the present invention;
[0040] Figure 2 This is a schematic diagram of another fuel cell system provided in Embodiment 1 of the present invention;
[0041] Figure 3 This is a schematic diagram of another fuel cell system provided in Embodiment 1 of the present invention;
[0042] Figure 4 This is a schematic diagram of a fuel cell cooling system in a fuel cell system provided in Embodiment 1 of this utility model. Detailed Implementation
[0043] The present invention will be further illustrated by way of embodiments below, but the present invention is not limited to the scope of the embodiments described herein.
[0044] In this embodiment of the invention, prefixes such as "first" and "second" are used merely to distinguish different descriptive objects and do not limit the position, order, priority, quantity, or content of the described objects. The use of ordinal numbers and other prefixes to distinguish descriptive objects in this embodiment of the invention does not constitute a limitation on the described objects. The description of the described objects is found in the claims or the context of the embodiments, and the use of such prefixes should not constitute unnecessary limitations. Furthermore, in the description of this embodiment, unless otherwise stated, "multiple" means two or more.
[0045] Example 1
[0046] Figure 1 This is a schematic diagram of a fuel cell system provided in an embodiment of the present invention. The fuel cell system includes a fuel cell 101, a power supply module 102, a first isolation device 103, a second isolation device 104, and a controller ( Figure 1 (not shown) and a fuel cell cooling system 105, the fuel cell cooling system 105 including a conductivity meter ( Figure 1 (Not shown in the image), used to detect the conductivity of the coolant.
[0047] One end of the first isolation device 103 is connected to the positive terminal of the fuel cell 101, and the other end of the first isolation device 103 is connected to the input positive terminal of the power supply module 102.
[0048] One end of the second isolation device 104 is connected to the negative electrode of the fuel cell 101, and the other end of the second isolation device 104 is connected to the input negative electrode of the power supply module 102.
[0049] The controller is connected to the control terminal of the first isolation device 103 and the control terminal of the second isolation device 104, respectively.
[0050] The conductivity meter is electrically connected to the controller; the controller is used to receive the conductivity detected by the conductivity meter, and control the first isolation device and the second isolation device to conduct when the conductivity is less than a first preset value; the power supply module is used to supply power to external components.
[0051] In this embodiment, the fuel cell and power supply module are physically isolated by adding isolation devices. If the fuel cell insulation is low, external components cannot start. These external components refer to parts outside the fuel cell system in the vehicle, such as the drive motor. Only when the controller receives a conductivity value lower than a first preset value does it indicate that the insulation performance meets the requirements. At this point, the first and second isolation devices are activated, allowing the fuel cell to output voltage to the power supply module, thereby powering the external components. This improves the insulation performance of the fuel cell system, optimizes its safety performance, and reduces vehicle costs.
[0052] In the specific implementation process, when the first isolation device and the second isolation device are turned on, it means that the fuel cell system has entered the standby state and can provide power to the external components of the vehicle, that is, to power the whole vehicle. For example, when the controller receives the vehicle start signal, the controller can control the vehicle's drive motor to run.
[0053] In one optional implementation, both the first isolation device and the second isolation device are normally open relays.
[0054] One end of the first isolation device is the common terminal or normally open contact of a normally open relay, and the other end of the first isolation device is the normally open contact or common terminal of a normally open relay.
[0055] One end of the second isolation device is the common terminal or normally open contact of a normally open relay, and the other end of the second isolation device is the normally open contact or common terminal of a normally open relay.
[0056] In one alternative implementation, such as Figure 2 As shown, the fuel cell system also includes a relay box 106, and the first isolation device 103 and the second isolation device 104 are both located inside the relay box 106.
[0057] In practical implementation, arcing is prone to occur at the contacts of DC power supplies, which can easily cause relay contact failure and adhesion between the moving and fixed contacts. Relay adhesion prevents the fuel cell from achieving physical isolation from external components and affects the safety of the fuel cell system. Therefore, since both the first and second isolation devices are normally open relays, adhesion detection is required. Two detection methods are used:
[0058] 1. The auxiliary contacts of the relay are detected. The controller receives the status of the auxiliary contacts and makes real-time judgments. When the main contacts should be open, the auxiliary contacts should also be open. If the auxiliary contacts are not open, it is determined that the main contacts are stuck.
[0059] 2. The voltage across the relay is monitored, and the controller receives the voltage across the relay for real-time judgment; when the relay should be disconnected, the voltage should drop to near zero; if the voltage is still high, the relay is judged to be stuck.
[0060] In one optional embodiment, the power supply module 102 includes a DC converter 1021 and a power distribution unit 1022.
[0061] The positive input terminal of DC converter 1021 is connected to the other end of the first isolation device 103, and the negative input terminal of DC converter 1021 is connected to the other end of the second isolation device 104; the output terminal of DC converter 1021 is connected to the input terminal of power distribution unit 1022.
[0062] The power distribution unit is used to distribute the voltage output by the DC-DC converter to the external components.
[0063] In this embodiment, the DC-DC converter (DCF, Converter for Fuel Cell) is used to convert the received DC voltage into a voltage suitable for the fuel cell system and external components, and distributes the voltage output by the DC-DC converter to each component through the power distribution unit (PDU).
[0064] In one optional embodiment, the positive input terminal of the power supply module is also connected to the positive terminal of the lithium battery, and the negative input terminal of the power supply module is also connected to the negative terminal of the lithium battery; the lithium battery is used to supply power to the fuel cell cooling system and the controller through the power supply module. In this embodiment, when the fuel cell system is connected to the lithium battery, the fuel cell cooling system and the controller are all in a power-on standby state after the lithium battery is powered on.
[0065] In one alternative embodiment, the fuel cell cooling system 105 further includes a water pump 1051, a deionizer 1052, a fan 1053, and a three-way valve 1054.
[0066] One end of the conductivity meter 1055 is connected to the output end of the water pump 1051 and the input end of the deionizer 1052, and the other end of the conductivity meter 1055 is connected to the input end of the fuel cell 101.
[0067] The output end of the water pump 1051 is connected to the input end of the fuel cell 101 and the input end of the deionizer 1052, respectively. The input end of the water pump 1051 is connected to one end of the fan 1053 and the first port of the three-way valve 1054, respectively.
[0068] The output end of the fuel cell 101 is connected to the second port of the three-way valve 1054, and the other end of the fan 1053 is connected to the third port of the three-way valve 1054.
[0069] The controller 107 is electrically connected to the three-way valve 1054 and the water pump 1051 respectively; the controller 107 is used to control the operation of the water pump when the conductivity is greater than or equal to the preset value.
[0070] In this embodiment, prolonged storage or coolant contamination can lead to increased conductivity of the coolant in the fuel cell cooling system circuit, resulting in low insulation of the fuel cell system. Therefore, this invention achieves physical isolation by adding an isolation device between the fuel cell and the power supply module. When the fuel cell system is connected to the lithium battery and powered on, a conductivity meter monitors the coolant conductivity in real time. If the conductivity is lower than a first preset value, the controller activates the first and second isolation devices to enable vehicle startup. If the conductivity is greater than or equal to the first preset value, the controller activates the water pump, driving the coolant in the circuit to circulate. The coolant flows through the water pump into the water circuits containing the fuel cell and the deionizer. The deionizer operates to reduce the ion concentration in the coolant, thereby decreasing the conductivity. Once the conductivity falls below the first preset value, the controller activates the first and second isolation devices to ensure insulation before vehicle startup.
[0071] In one optional embodiment, the fuel cell cooling system further includes a temperature sensor for detecting the temperature of the coolant; the temperature sensor is electrically connected to the controller.
[0072] The controller is also configured to receive the temperature detected by the temperature sensor, and control the first interface to be connected to the second interface when the temperature is less than a second preset value; and control the third interface to be connected to the second interface when the temperature is greater than or equal to the second preset value.
[0073] In this embodiment, when the temperature received by the controller is less than the second preset value, the controller connects the first interface to the second interface. The coolant in the fuel cell cooling system circuit bypasses the water path where the fan is located and flows directly from the first interface of the three-way valve into the water pump for circulation. When the temperature received by the controller is greater than or equal to the second preset value, the controller connects the third interface to the second interface. The coolant in the fuel cell cooling system circuit flows from the third interface of the three-way valve, passes through the water path where the fan is located for heat dissipation, and then flows into the water pump for circulation.
[0074] Example 2
[0075] This utility model also provides a vehicle comprising the fuel cell system as described in Embodiment 1. In this embodiment, the fuel cell and power supply module in the fuel cell system are physically isolated by adding isolation devices, solving the problems of decreased vehicle safety performance and increased cost in the prior art. When the controller in the fuel cell system receives a conductivity value lower than a first preset value, it controls the first and second isolation devices in the fuel cell system to conduct, thereby improving the insulation performance of the fuel cell system, optimizing the safety performance of the fuel cell system, and reducing vehicle cost.
[0076] In one optional embodiment, the vehicle further includes external components of the fuel cell system, which are connected to the output terminal of the power supply module in the fuel cell system. In this embodiment, when the controller in the fuel cell system receives a conductivity value less than a first preset value, it controls the first and second isolation devices in the fuel cell system to conduct. This allows the fuel cell to supply power to the external components through the power supply module, thereby ensuring the insulation performance before vehicle startup and guaranteeing vehicle safety.
[0077] In one alternative embodiment, the vehicle further includes a lithium battery, the positive terminal of which is connected to the positive input terminal of the power supply module, and the negative terminal of which is connected to the negative input terminal of the power supply module.
[0078] While specific embodiments of this utility model have been described above, those skilled in the art should understand that these are merely illustrative examples, and the scope of protection of this utility model is defined by the appended claims. Those skilled in the art can make various changes or modifications to these embodiments without departing from the principles and essence of this utility model, but all such changes and modifications fall within the scope of protection of this utility model.
Claims
1. A fuel cell system characterized by comprising: The fuel cell system comprises a fuel cell, a power supply module, a first isolation device, a second isolation device, a controller and a fuel cell cooling system, wherein the fuel cell cooling system comprises an electric conductivity meter for detecting the electric conductivity of the cooling liquid; One end of the first isolation device is connected to the positive electrode of the fuel cell, and the other end of the first isolation device is connected to the input positive electrode of the power supply module; One end of the second isolation device is connected to the negative electrode of the fuel cell, and the other end of the second isolation device is connected to the input negative electrode of the power supply module; The controller is connected to the control end of the first isolation device and the control end of the second isolation device respectively; The electric conductivity meter is electrically connected to the controller, and the controller is used for receiving the electric conductivity detected by the electric conductivity meter and controlling the first isolation device and the second isolation device to be turned on when the electric conductivity is less than a first preset value; and the power supply module is used for supplying power to external components.
2. The fuel cell system of claim 1, wherein, The first isolation device and the second isolation device are both normally open relays; One end of the first isolation device is the common end or the normally open contact of the normally open relay, and the other end of the first isolation device is the normally open contact or the common end of the normally open relay; One end of the second isolation device is the common end or the normally open contact of the normally open relay, and the other end of the second isolation device is the normally open contact or the common end of the normally open relay.
3. The fuel cell system of claim 2, wherein The fuel cell system further comprises a relay box, and the first isolation device and the second isolation device are both located inside the relay box.
4. The fuel cell system of claim 1, wherein The power supply module comprises a DC converter and a power distribution unit; The input positive electrode of the DC converter is connected to the other end of the first isolation device, and the input negative electrode of the DC converter is connected to the other end of the second isolation device; The output end of the DC converter is connected to the input end of the power distribution unit; The power distribution unit is used for distributing the voltage output by the DC converter to the external components.
5. The fuel cell system of claim 1, wherein The input positive electrode of the power supply module is further connected to the positive electrode of a lithium battery, and the input negative electrode of the power supply module is further connected to the negative electrode of the lithium battery; The lithium battery is used for supplying power to the fuel cell cooling system and the controller through the power supply module.
6. The fuel cell system of claim 5, wherein, The fuel cell cooling system further comprises a water pump, a deionizer, a fan and a three-way valve; One end of the electric conductivity meter is connected to the output end of the water pump and the input end of the deionizer respectively, and the other end of the electric conductivity meter is connected to the input end of the fuel cell; The output end of the water pump is connected to the input end of the fuel cell and the input end of the deionizer respectively, and the input end of the water pump is connected to one end of the fan and a first interface of the three-way valve respectively; The output end of the fuel cell is connected to a second interface of the three-way valve, and the other end of the fan is connected to a third interface of the three-way valve; The controller is electrically connected to the three-way valve and the water pump respectively; The controller is used for controlling the water pump to operate when the electric conductivity is greater than or equal to the preset value.
7. The fuel cell system of claim 6, wherein The fuel cell cooling system further comprises a temperature sensor for detecting the temperature of the cooling liquid; the temperature sensor is electrically connected to the controller; The controller is further configured to receive the temperature detected by the temperature sensor, and control the first interface and the second interface to be conductive when the temperature is less than a second preset value; and control the third interface and the second interface to be conductive when the temperature is greater than or equal to the second preset value.
8. A vehicle characterized by comprising: The vehicle comprises the fuel cell system according to any one of claims 1-7.
9. The vehicle of claim 8, wherein, The vehicle further comprises an external component of the fuel cell system, the external component being connected to an output end of a power supply module in the fuel cell system.
10. The vehicle of claim 8, wherein, The vehicle further comprises a lithium battery, a positive electrode of the lithium battery being connected to an input positive electrode of the power supply module, and a negative electrode of the lithium battery being connected to an input negative electrode of the power supply module.