Fuel cell engine power balance control method and control system

Abstract

The invention discloses a fuel cell engine power balance control method and control system, and the method comprises the steps that an electric pile receives an input material to reach a power generation standard, and the material comprises air, hydrogen or water; adjusting the conveying pressure and flow of the material to a working condition value corresponding to the rated output power of the electric pile; a voltage booster and a load are started, the electric pile supplies power to the load through the voltage booster, and the power of the load is adjusted so that the electric pile can be adjusted to the corresponding output current; the fuel cell control system uses external power supply, and the booster works in an output constant voltage mode during operation; when the fuel cell works at a working point corresponding to rated power, the current response speed of the stack can be directly improved by adjusting the power of the load; the electric pile can be independently used as a voltage source to supply power to a load without configuring a voltage source such as a lithium battery, so that the cost is saved.

Description

Technical Field

[0001] The present invention relates to the technical field of fuel cell engines, and in particular to a fuel cell engine power balance control method and control system. Background Art

[0002] During fuel cell operation, a target current command is sent to the fuel cell controller. The DC-DC booster then controls the current at the DC-DC booster input based on this target current command. When the fuel cell is powering a load, a lithium battery is connected in parallel at the DC-DC booster output to provide power to the load. Because fuel cells have a slow load-changing speed, the air supply flow must be adjusted to a level corresponding to the operating current to ensure continuous operation of the stack. This also requires calculating the fuel cell's target current based on the load power.

[0003] In the existing technical solutions, the power supply for components such as the air compressor, water pump, and circulating pump is supplied by the DC bus at the output end of the DC-DC booster. Therefore, the output end of the DC-DC booster must have an external voltage source (such as a lithium battery) as a starting power source and a voltage source for the DC-DC booster to work; the fuel cell controller controls the current at the input end of the DC-DC booster according to the received target current or target power, and loads it to the target operating point. Since the DC-DC booster is in input constant current control mode, the DC-DC booster current and the fuel cell fuel supply and cooling system respond to the target current signal of the fuel cell controller.

[0004] However, in the above scheme, the output power of the fuel cell system can only be controlled by the target current command calculated by the fuel cell controller and cannot quickly follow the load changes. Summary of the Invention

[0005] The purpose of the present invention is to solve the shortcomings of the prior art and to propose a fuel cell engine power balance control method and control system.

[0006] In order to achieve the above-mentioned object, the present invention adopts the following technical solution: a fuel cell engine power balance control method, comprising:

[0007] The stack receives input materials that meet power generation standards, wherein the materials include air, hydrogen or water;

[0008] Adjusting the conveying pressure and flow rate of the material to the operating values ​​corresponding to the rated output power of the fuel cell stack;

[0009] The booster and the load are started, the fuel cell stack supplies power to the load through the booster, and the power of the load is adjusted so that the fuel cell stack is adjusted to a corresponding output current.

[0010] As a further description of the above technical solution: the method for the fuel cell stack to receive input materials and meet the power generation standards includes:

[0011] The stack receives materials for generating electricity after reaching the power generation standard;

[0012] The stack receives the supplied water for cooling;

[0013] Water vapor is delivered to the fuel cell stack to maintain the humidity inside the fuel cell stack at a power generation standard.

[0014] As a further description of the above technical solution: the method for adjusting the conveying pressure and flow rate of the material to the operating value corresponding to the rated output power of the fuel cell stack includes:

[0015] monitoring the state of the fuel cell stack according to the rated output power of the fuel cell stack;

[0016] Determine whether the state of the battery stack is abnormal based on the preset detection standard. If yes, adjust the material delivery rate. If not, continue to deliver the material until the operating value corresponding to the rated output power of the battery stack is reached, and maintain the material delivery rate.

[0017] As a further description of the above technical solution: the booster is a DC booster, and the output voltage is a constant voltage.

[0018] Also included is a fuel cell engine power balance control system, including:

[0019] Battery stack;

[0020] The fuel cell stack is provided with an air delivery system, a hydrogen delivery system and a cooling system;

[0021] The output end of the battery stack is electrically connected to a booster;

[0022] The output end of the booster is electrically connected to a load, and the fuel cell stack is adjusted to a corresponding output current by adjusting the power of the load.

[0023] As a further description of the above technical solution: the air delivery system includes an air compressor, and the output end of the air compressor is connected to the input end of the fuel cell stack.

[0024] As a further description of the above technical solution: the hydrogen delivery system includes a hydrogen injection pump, the output end of the hydrogen injection pump is connected to the input end of the fuel cell stack, the output end of the fuel cell stack is connected to a hydrogen circulation pump, and the output end of the hydrogen circulation pump is connected to the hydrogen injection pump.

[0025] As a further description of the above technical solution: the cooling system includes a water pump, the output end of the water pump is connected to the input end of the fuel cell stack, and the output end of the fuel cell stack is connected to the water pump.

[0026] As a further description of the above technical solution: the air delivery system, the hydrogen delivery system and the cooling system are powered by a power supply.

[0027] As a further description of the above technical solution: a humidification system is also provided on the fuel cell stack, which transports water vapor to the output end of the air compressor, mixes with air and transports it to the fuel cell stack.

[0028] The above technical solution has the following advantages or beneficial effects:

[0029] The fuel cell control system uses external power supply, and the booster works in output constant voltage mode during operation; the fuel cell operates at the operating point corresponding to the rated power, and the current response speed of the stack can be directly improved by adjusting the power of the load; the stack can be used as a separate voltage source to power the load, without the need to configure a voltage source such as a lithium battery, saving costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0031] Figure 1 Flowchart of the control method proposed by the present invention;

[0032] Figure 2 A flow chart of a method for a fuel cell stack in the present invention to receive input materials and meet power generation standards;

[0033] Figure 3 This is a flow chart of the method for adjusting the material delivery pressure and flow rate to the operating value corresponding to the rated output power of the fuel cell stack in the present invention;

[0034] Figure 4 This is a structural principle diagram of the control system proposed by the present invention.

[0035] Legend:

[0036] 1. Fuel cell stack; 2. Booster; 3. Load; 4. Air compressor; 5. Hydrogen injection pump; 6. Hydrogen circulation pump; 7. Water pump; 8. Humidification system. DETAILED DESCRIPTION

[0037] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0038] Reference Figure 1 The present invention provides an embodiment of a fuel cell engine power balance control method, comprising:

[0039] S1: The stack receives input materials that meet power generation standards, where the materials include air, hydrogen, or water;

[0040] S2: Adjust the material delivery pressure and flow rate to the operating value corresponding to the rated output power of the fuel cell stack;

[0041] S3: Start the booster and the load. The fuel cell stack supplies power to the load through the booster. The power of the load is adjusted so that the fuel cell stack is adjusted to the corresponding output current.

[0042] In this embodiment, the air, hydrogen, water and other materials received by the fuel cell stack must meet the power generation standards so that the electrochemical reaction inside the fuel cell stack can proceed smoothly, avoiding abnormal power generation caused by poor material quality or unstable supply.

[0043] Adjusting the material delivery pressure and flow rate to the operating conditions corresponding to the rated output power of the fuel cell stack can ensure that the fuel cell stack operates at its optimal state. By precisely controlling the material parameters, the fuel cell stack can output according to the designed rated power, improving power generation efficiency. Under different load power requirements, the pressure and flow of hydrogen and air are adjusted to match the electrochemical reaction rate with the power demand.

[0044] By adjusting the load power, the stack output current is adjusted to the corresponding output current, allowing the stack output to adapt to different load requirements. The booster increases the stack output voltage to meet the load's operating voltage requirements. Controlling the stack output current by adjusting the load power ensures a good power match between the stack and the load. Even with varying loads, the stack output current can be adjusted promptly to maintain power balance, ensuring normal load operation and improving system stability and reliability.

[0045] Reference Figure 2 , the methods for the fuel cell stack to receive input materials and meet power generation standards include:

[0046] S11: The fuel cell stack receives materials and generates electricity after meeting the power generation standards;

[0047] S12: The stack receives the delivered water for cooling;

[0048] S13: Supply water vapor to the fuel cell stack to maintain the humidity inside the fuel cell stack at the power generation standard.

[0049] In this embodiment, components such as the air compressor, water pump, hydrogen injection pump and hydrogen circulation pump are started. The air compressor provides air to the fuel cell stack and adjusts the air pressure and flow rate. The hydrogen injection pump provides hydrogen to the fuel cell stack and adjusts the hydrogen pressure. The hydrogen circulation pump adjusts the flow rate of hydrogen flowing through the fuel cell stack. The water pump dissipates heat for the fuel cell stack. Air and hydrogen enter the fuel cell stack, causing the fuel cell stack to react after reaching the power generation standard, and the fuel cell stack starts to generate electricity.

[0050] Reference Figure 3 The method for adjusting the material delivery pressure and flow rate to the operating value corresponding to the rated output power of the fuel cell stack includes:

[0051] S21: monitoring the status of the fuel cell stack according to the rated output power of the fuel cell stack;

[0052] S22: Determine whether the state of the battery stack is abnormal based on the preset detection standard. If yes, adjust the material conveying rate. If not, continue to convey the material until the operating value corresponding to the rated output power of the battery stack is reached, and maintain the material conveying rate.

[0053] In this embodiment, by continuously monitoring key parameters of the stack, such as voltage, current, temperature, and pressure, changes in the stack during operation can be detected promptly. Based on preset detection criteria, the stack status can be determined to be abnormal, and the material delivery rate can be adjusted accordingly. This process enables a rapid response to abnormal stack operation. When the stack status is abnormal, the material delivery rate can be adjusted to intervene in the stack's operation.

[0054] Specifically, when the fuel cell stack is operating, it needs to reach a certain humidity level for the electrochemical reaction to generate electricity normally. The water generated during operation cannot achieve the optimal humidity level inside the stack. When the humidity is low, the catalyst activity inside the stack will deteriorate, reducing power generation efficiency. Therefore, it is necessary to activate the humidification system and adjust the water vapor spray flow rate according to the stack air temperature and air flow to control the air humidity and prevent the stack from over-drying. During operation, the cooling system is controlled to maintain a constant water temperature at the stack inlet.

[0055] The water blockage, over-dryness, and over-humidity inside the stack are detected by AC impedance or aerodynamic impedance technology to determine whether there is an abnormality. The detection standard is calibrated during the stack test. When an abnormality is detected, determine what the condition is:

[0056] When the water blocking sign is detected, increase the speed of the hydrogen circulation pump and the air flow rate;

[0057] When the over-humidity mark is detected, the water vapor spray flow rate is reduced or the air flow rate is increased;

[0058] When the over-dryness sign is detected, increase the water vapor spray flow rate or decrease the air flow rate.

[0059] If no abnormality is detected, adjust the air compressor speed, water pump speed, and circulating pump speed to make the air pressure, flow, hydrogen pressure, flow, and water flow reach the operating values ​​corresponding to the rated output power.

[0060] The booster is a DC booster and its output voltage is constant.

[0061] In this embodiment, the booster is a DC-DC booster, and the booster outputs a constant voltage of 600V (the rated voltage set by the system); the booster input voltage is determined by the stack voltage, and the booster input current = load power / boost input voltage. Specifically, when the load power increases, the booster output voltage remains unchanged, and the current increases. At this time, the overall power of the booster output increases, and the booster input current needs to increase, control the stack current to increase, and reduce the stack voltage until power balance is achieved.

[0062] Reference Figure 4 , also includes an embodiment of a fuel cell engine power balance control system, comprising:

[0063] Battery stack 1;

[0064] The fuel cell stack 1 is provided with an air delivery system, a hydrogen delivery system and a cooling system;

[0065] The output end of the battery stack 1 is electrically connected to the booster 2;

[0066] The output end of the booster 2 is electrically connected to the load 3 , and the fuel cell stack 1 is adjusted to a corresponding output current by adjusting the power of the load 3 .

[0067] In this embodiment, the fuel cell stack 1 generates electricity through an electrochemical reaction using air provided by the air delivery system and hydrogen provided by the hydrogen delivery system. The cooling system ensures that the fuel cell stack operates at an appropriate temperature, preventing excessive temperatures from affecting performance or even damaging the fuel cell stack 1. The electricity generated by the fuel cell stack 1 passes through a booster 2, which increases the voltage output of the fuel cell stack to meet the operating voltage requirements of the load 3. By adjusting the power of the load 3, the output current of the fuel cell stack 1 can be controlled, ensuring that the fuel cell stack 1 operates in an appropriate state, achieving power balance, and outputting electricity on demand.

[0068] The air delivery system includes an air compressor 4 , the output end of the air compressor 4 is connected to the input end of the fuel cell stack 1 .

[0069] In this embodiment, the air compressor 4 delivers air to the inner side of the end for electrochemical reaction. The air compressor 4 can provide a larger air flow and a higher delivery pressure to reduce the incomplete reaction caused by insufficient air. The air compressor 4 can also accurately adjust the air flow. When the load suddenly increases, the air compressor 4 can speed up the operation and increase the air delivery volume to ensure that the fuel cell stack has sufficient energy output and maintain the stability of the system.

[0070] The hydrogen delivery system includes a hydrogen injection pump 5 , the output end of the hydrogen injection pump 5 is connected to the input end of the fuel cell stack 1 , the output end of the fuel cell stack 1 is connected to a hydrogen circulation pump 6 , and the output end of the hydrogen circulation pump 6 is connected to the hydrogen injection pump 5 .

[0071] In this embodiment, hydrogen can be delivered to the inside of the fuel cell stack 1 by the hydrogen injection pump 5 for electrochemical reaction. The fuel cell stack 1 can re-deliver the incompletely reacted hydrogen to the hydrogen injection pump 5 through the hydrogen circulation pump 6 for circulation, thereby improving the utilization rate of the hydrogen and helping to stabilize the hydrogen pressure and concentration inside the fuel cell stack 1. Through continuous circulation, the distribution of hydrogen is more uniform, avoiding the situation where the local hydrogen concentration is too high or too low.

[0072] The cooling system includes a water pump 7 , the output end of the water pump 7 is connected to the input end of the fuel cell stack 1 , and the output end of the fuel cell stack 1 is connected to the water pump 7 .

[0073] In this embodiment, water circulation cooling is performed by the water pump 7. By adjusting the flow rate and pressure of the water pump 7, the circulation speed of the coolant can be accurately controlled, and the temperature of the fuel cell stack can be accurately controlled to cool the fuel cell stack 1.

[0074] The air delivery system, hydrogen delivery system and cooling system are powered by the power supply.

[0075] In this embodiment, the air delivery system, hydrogen delivery system and cooling system are powered by an external power supply, and do not need to be powered by a lithium battery connected in parallel between the booster and the load.

[0076] A humidification system 8 is also provided on the fuel cell stack to transport water vapor to the output end of the air compressor 4, where it is mixed with air and transported to the fuel cell stack.

[0077] In this embodiment, the humidification system 8 is used to transport water vapor spray, which is transported to the output end of the air compressor 4 through a pipeline and mixed with air before being transported to the inside of the fuel cell stack 1 to adjust the water state inside the fuel cell stack and prevent the fuel cell stack from being too dry.

[0078] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A fuel cell engine power balance control method, characterized in that: include: The stack receives input materials that meet power generation standards, wherein the materials include air, hydrogen or water; Adjusting the conveying pressure and flow rate of the material to the operating values ​​corresponding to the rated output power of the fuel cell stack; The booster and the load are started, the fuel cell stack supplies power to the load through the booster, and the power of the load is adjusted so that the fuel cell stack is adjusted to a corresponding output current.

2. The control method according to claim 1, wherein: Methods for the stack to receive input materials and meet power generation standards include: The stack receives materials for generating electricity after reaching the power generation standard; The stack receives the supplied water for cooling; Water vapor is delivered to the fuel cell stack to maintain the humidity inside the fuel cell stack at a power generation standard.

3. The control method according to claim 1, wherein: The method of adjusting the conveying pressure and flow rate of the material to an operating value corresponding to the rated output power of the fuel cell stack includes: monitoring the state of the fuel cell stack according to the rated output power of the fuel cell stack; Determine whether the state of the battery stack is abnormal based on the preset detection standard. If yes, adjust the material delivery rate. If not, continue to deliver the material until the operating value corresponding to the rated output power of the battery stack is reached, and maintain the material delivery rate.

4. The control method according to claim 1, wherein: The booster is a DC booster, and the output voltage is a constant voltage.

5. A fuel cell engine power balance control system, characterized in that: include: Battery stack; The fuel cell stack is provided with an air delivery system, a hydrogen delivery system and a cooling system; The output end of the battery stack is electrically connected to a booster; The output end of the booster is electrically connected to a load, and the fuel cell stack is adjusted to a corresponding output current by adjusting the power of the load.

6. The control system according to claim 5, characterized in that: The air delivery system includes an air compressor, and the output end of the air compressor is connected to the input end of the fuel cell stack.

7. The control system according to claim 5, characterized in that: The hydrogen delivery system includes a hydrogen injection pump, the output end of the hydrogen injection pump is connected to the input end of the fuel cell stack, the output end of the fuel cell stack is connected to a hydrogen circulation pump, and the output end of the hydrogen circulation pump is connected to the hydrogen injection pump.

8. The control system according to claim 5, characterized in that: The cooling system includes a water pump, the output end of the water pump is connected to the input end of the fuel cell stack, and the output end of the fuel cell stack is connected to the water pump.

9. The control system according to claim 5, characterized in that: The air delivery system, the hydrogen delivery system and the cooling system are powered by a power supply.

10. The control system according to claim 6, characterized in that: The fuel cell stack is also provided with a humidification system to transport water vapor to the output end of the air compressor, where it is mixed with air and transported to the fuel cell stack.

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