A fuel cell energy management control method, system and apparatus

Abstract

This invention discloses a fuel cell energy management and control method, system, and device. The method includes: step S1, acquiring the lithium battery SOC status, lithium battery current setpoint, and measured lithium battery current value via a CAN bus; step S2, determining the fuel cell's power supply state based on the lithium battery SOC status; if satisfied, the fuel cell enters a working mode, controlling the fuel cell output according to the lithium battery current setpoint and measured value, enabling the fuel cell and lithium battery to collaboratively supply power to the power generation system load; if not satisfied, the fuel cell enters a dormant mode, with the lithium battery independently supplying power to the power generation system load. This invention employs power following based on the lithium battery current as the control target, increasing the proportion of fuel cells in power generation and improving the efficiency of air-cooled power generation systems; simultaneously, by using the lithium battery current as the control variable target, it can protect the lithium battery and extend its service life.

Description

Technical Field

[0001] This invention relates to the field of fuel cell technology, and more specifically, to a fuel cell energy management and control method, system, and device. Background Technology

[0002] Air-cooled fuel cell power generation systems use hydrogen fuel cells as the primary power source, achieving completely pollution-free emissions. However, fuel cells have insufficient dynamic response capabilities, requiring the addition of lithium batteries as auxiliary energy to improve system dynamic response. However, the charging and discharging losses of lithium batteries during energy conversion lead to a decrease in overall power generation efficiency. To balance efficiency and dynamic performance, the power contribution of fuel cells in the power generation process needs to be significantly increased.

[0003] In the prior art, Chinese invention patent with publication number CN115498222A discloses an energy management method for a low-power air-cooled fuel cell. In this method, firstly, there is a state where the fuel cell works alone, which will lead to a deterioration in the dynamic response capability of the entire system; secondly, if the fuel cell is continuously operated at its optimal efficiency operating point (at which the power is low), although the efficiency can be improved, it will lead to a waste of fuel cell performance (not fully utilizing the high power potential) and a surge in the cost of the lithium battery system. If the requirements for the charging and discharging capacity of the lithium battery are reduced, its capacity needs to be increased, resulting in an increase in volume and cost. If a small capacity battery is maintained, a higher charging and discharging capacity is required, which will significantly increase the cost.

[0004] Chinese invention patent CN117162874A discloses an energy management and control method and system for on-board hydrogen-oxygen fuel cells. When determining the power demand of the fuel cell engine based on the two-dimensional mapping relationship between the current vehicle load mode and the state of charge (SOC) of the lithium battery, the lithium battery absorbs more electrical energy generated by the fuel cell under certain operating conditions, and then outputs this part of electrical energy to the load of the power generation system, increasing energy conversion loss and reducing the overall efficiency of the fuel cell system.

[0005] Therefore, a new solution is needed to address the above problems. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of the prior art and provide a fuel cell energy management and control method, system and device.

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

[0008] A fuel cell energy management and control method includes the following steps:

[0009] Step S1: Obtain the lithium battery SOC status, lithium battery current setpoint, and lithium battery current measured value via the CAN bus;

[0010] Step S2: Determine the power supply status of the fuel cell based on the SOC status of the lithium battery. If the conditions are met, the fuel cell enters the working mode, and the output and proportion of the fuel cell are dynamically controlled according to the set value and measured value of the lithium battery current, so that the fuel cell and the lithium battery work together to supply power to the load of the power generation system. If the conditions are not met, the fuel cell enters the dormant mode, and the lithium battery supplies power to the load of the power generation system independently.

[0011] Furthermore, in step S2, the difference between the measured value and the set value of the lithium battery current is used as the control input. After the target output current of the fuel cell system is generated by the PID control algorithm, it is input to the fuel cell output control module to control the output of the fuel cell power.

[0012] Furthermore, the process of generating the target output current of the fuel cell system is as follows:

[0013] Step S21, using the measured value of the lithium battery current. With set value The difference between them is used as a control input, and its expression is:

[0014]

[0015] Step S22, adjust the lithium battery current deviation As input, the target output current of the fuel cell system is generated, and its expression is:

[0016]

[0017] In the formula, It is a time variable; This is the proportionality coefficient; The integral coefficient; These are the differential coefficients; The target output current for the fuel cell system; Indicates lithium battery current deviation Accumulated amount over time; Indicates lithium battery current deviation The rate of change.

[0018] Furthermore, during the collaborative power supply process of fuel cells and lithium batteries, the operating state of the lithium battery is adjusted according to the output power of the fuel cell: when the output power of the fuel cell is greater than or equal to the load demand, the lithium battery works as an energy absorption unit; when the output power of the fuel cell is less than the load demand, the lithium battery works as an energy replenishment unit.

[0019] The present invention also provides a fuel cell energy management and control system, the system comprising:

[0020] Hydrogen storage system, used to provide hydrogen for generating electricity from fuel cells;

[0021] The fuel cell system includes a fuel cell and a fuel cell output control module. The fuel cell directly converts chemical energy into electrical energy through the electrochemical reaction of hydrogen and oxygen, supplying power to the load of the power generation system and charging the lithium battery. The fuel cell output control module receives instructions from the energy management system and, through a PID control algorithm, calculates and issues a target output current command in real time based on the difference between the measured value and the set value of the lithium battery current, so that the output of the fuel cell can accurately track the power demand of the power generation system load.

[0022] The power system includes a lithium battery and a power management module. The lithium battery supplies power to the load of the power generation system and stores excess electrical energy generated by the fuel cell. The power management module is responsible for the conversion, distribution and transmission of electrical energy, ensuring that the electrical energy output from the fuel cell and the lithium battery can be reliably combined to meet the power requirements of the power generation system load.

[0023] The energy management system is used to acquire the lithium battery SOC status, lithium battery current setpoint, and lithium battery current measured value in real time. Based on the lithium battery SOC status, it controls the operating mode of the fuel cell and executes a PID control algorithm with the lithium battery current as the control target. It sends commands to the fuel cell output control module to achieve precise power distribution and tracking.

[0024] The present invention also provides a fuel cell energy management and control device, comprising:

[0025] Memory, used to store computer programs and data;

[0026] A processor is used to execute computer programs to implement the steps of the above-described fuel cell energy management and control method.

[0027] The beneficial effects of this invention are:

[0028] This invention employs power following based on lithium battery current as the control target, which increases the proportion of fuel cells in power generation and can improve the efficiency of wind-cooled power generation systems. At the same time, by using lithium battery current as the control variable target, it can protect the lithium battery and extend its working life. Attached Figure Description

[0029] Figure 1 This is a flowchart of a fuel cell energy management and control method in this embodiment;

[0030] Figure 2 This is a flowchart illustrating the generation of the target output current of the fuel cell system in this embodiment;

[0031] Figure 3 This is a schematic diagram of a fuel cell energy management and control device in this embodiment.

[0032] Reference numerals: 1. Hydrogen storage system; 2. Fuel cell system; 21. Fuel cell; 22. Fuel cell output control module; 3. Power system; 31. Lithium battery; 32. Power management module; 4. Energy management system; 5. Memory; 6. Processor. Detailed Implementation

[0033] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] Example: In the prior art, a small air-cooled fuel cell power generation system generally includes a hydrogen storage system 1, a fuel cell system 2, and a power supply system 3. In the fuel cell system 2, the fuel cell 21 and the lithium battery 31 in the power supply system 3 jointly participate in power supply. The load power of the power generation system is equal to the sum of the output power of the fuel cell 21 and the power of the lithium battery 31.

[0035] Since the voltage platform of lithium battery 31 and fuel cell 21 remains stable when outputting power, precise tracking of the load power of the power generation system can be achieved by adjusting the current of lithium battery 31 and fuel cell 21.

[0036] (1)

[0037] In equation (1), The load power of the power generation system; This provides the output current for fuel cell 21; For lithium batteries, the current is 31. The voltage platform for the operation of fuel cell 21 and lithium battery 31.

[0038] A fuel cell energy management and control method, such as Figure 1 As shown, it includes the following steps:

[0039] Step S1: Obtain the required data via CAN bus: SOC status of lithium battery 31, current setting value of lithium battery 31, and measured current value of lithium battery 31.

[0040] Step S2: Determine the power supply status of fuel cell 21 based on the SOC status of lithium battery 31. If the conditions are met, enter the working mode of fuel cell 21, start fuel cell 21, and dynamically control the output and proportion of fuel cell 21 according to the current set value and measured value of lithium battery 31, so that fuel cell 21 and lithium battery 31 work together to supply power to the load of power generation system. If the conditions are not met, enter the sleep mode of fuel cell 21, shut down fuel cell 21, and supply power to the load of power generation system independently by lithium battery 31, that is, the output power of lithium battery 31 is equal to the load power of power generation system.

[0041] This implementation method uses the current of lithium battery 31 as the control target. The charging current is set by the charging and discharging capacity of lithium battery 31 and the overall power of the system. This indirectly realizes power following control, increases the efficiency of the small air-cooled fuel cell power generation system, and at the same time, using the current of lithium battery 31 as the control variable target can protect lithium battery 31, extend the working life of lithium battery 31, reduce the requirements of lithium battery 31, and reduce costs.

[0042] Furthermore, in step S2, the difference between the measured value and the set value of the lithium battery 31 current is used as the control input. After generating the target output current of the fuel cell system 2 through the PID control algorithm, it is input to the fuel cell output control module 22 to control the power output of the fuel cell 21. By adopting the PID control algorithm, the target output current is calculated and generated in real time based on the deviation of the lithium battery 31 current, so that the output of the fuel cell 21 can accurately track the load power demand of the power generation system.

[0043] Specifically, such as Figure 2 As shown, the process of generating the target output current of fuel cell system 2 is as follows:

[0044] Step S21, using the measured value of the current of lithium battery 31 With set value The difference between them is used as a control input, and its expression is:

[0045] (2)

[0046] Step S22, adjust the current deviation of lithium battery 31 As input, the target output current of fuel cell system 2 is generated, and its expression is:

[0047] (3)

[0048] In the formula, It is a time variable; This is the proportionality coefficient; The integral coefficient; These are the differential coefficients; The target output current for fuel cell system 2; Indicates the current deviation of lithium battery 31 The cumulative amount over time, i.e., the current deviation of the lithium battery 31 The integral; Indicates the current deviation of lithium battery 31 The rate of change, i.e., the current deviation of lithium battery 31 The differential.

[0049] By generating the target output current of fuel cell system 2, the output of fuel cell 21 is dynamically adjusted to ensure stable load power of the power generation system and optimize energy distribution.

[0050] During the collaborative power supply process of fuel cell 21 and lithium battery 31, lithium battery 31 is passively regulated, and its operating state is adjusted according to the output power of fuel cell 21, resulting in the following two operating conditions:

[0051] 1. When the output power of fuel cell 21 is in excess, that is, the output power of fuel cell 21 is greater than or equal to the load demand, the lithium battery 31 works as an energy absorption unit. At this time, the system satisfies: the load power of the power generation system = the output power of fuel cell - the input power of lithium battery.

[0052] 2. When the output power of fuel cell 21 is insufficient, that is, when the output power of fuel cell 21 is less than the load demand, lithium battery 31 works as an energy supplement unit. At this time, the system satisfies: power generation system load power = fuel cell output power + lithium battery input power.

[0053] The output and proportion of fuel cell 21 are dynamically controlled based on the set value and measured value of the lithium battery 31 current. Specifically, when the required current is 50A, the proportion of fuel cell 21 is determined by controlling the set value of the charging current of lithium battery 31.

[0054] When the charging current setting of lithium battery 31 is 0, the output of fuel cell 21 needs to be equal to the power demand of the system.

[0055] When the charging current of lithium battery 31 is set to 5A (or a positive value), the output of fuel cell 21 needs to be equal to the system's required power plus the charging power of lithium battery 31.

[0056] When the charging current of lithium battery 31 is set to -5A (or negative), the output of fuel cell 21 plus the discharge power of lithium battery 31 must equal the power required by the system.

[0057] The charging current setting value of lithium battery 31 can be set according to the state of charge (SOC) of lithium battery 31, for example:

[0058] When the SOC of lithium battery 31 is 0-30%, the set value is 5A, and lithium battery 31 needs to be charged. The output of fuel cell 21 is equal to the system's required power plus the charging power of lithium battery 31.

[0059] When the SOC of lithium battery 31 is 30-70%, the set value is 0A, and fuel cell 21 needs to work alone.

[0060] When the SOC of lithium battery 31 is 70-100%, the set value is -5A. Fuel cell 21 and lithium battery 31 need to output energy together. The output of fuel cell 21 plus the discharge power of lithium battery 31 equals the power required by the system.

[0061] If the system demand exceeds the output power of fuel cell 21, then regardless of the set value, lithium battery 31 will output energy. The output of fuel cell 21 plus the discharge power of lithium battery 31 equals the system demand power.

[0062] This embodiment also provides a fuel cell energy management and control system, such as Figure 1 As shown, the system includes a hydrogen storage system 1, a fuel cell system 2, a power supply system 3, and an energy management system 4.

[0063] The hydrogen storage system 1 is used to safely store and supply hydrogen required for the fuel cell 21 to generate electricity.

[0064] The fuel cell system 2 includes a fuel cell 21 and a fuel cell output control module 22. The fuel cell 21 directly converts chemical energy into electrical energy through the electrochemical reaction of hydrogen and oxygen, supplying power to the load of the power generation system and charging the lithium battery 31. The fuel cell 21 is one of the two main power sources of the power generation system, working in conjunction with the lithium battery 31. Its output current is directly controlled by the energy management control method to meet the power demand of the power generation system load.

[0065] The fuel cell output control module 22 is used to receive instructions from the energy management system 4 and dynamically adjust the output current of the fuel cell 21. Specifically, through the PID control algorithm, the target output current instruction is calculated in real time based on the difference between the measured value and the set value of the lithium battery 31 current, so that the output of the fuel cell 21 can accurately track the load power demand of the power generation system. That is, the above formula (3) is used to adjust the output of the fuel cell 21 to ensure that the current of the lithium battery 31 is stable near the set value.

[0066] The power system 3 includes a lithium battery 31 and a power management module 32. The lithium battery 31 is used to supply power to the load of the power generation system and to store excess electrical energy generated by the fuel cell 21. Specifically, when the fuel cell 21 is in dormant mode, the lithium battery 31 independently supplies power to the load of the power generation system; when the fuel cell 21 is in operating mode, if the output power of the fuel cell 21 is greater than or equal to the load demand, the lithium battery 31 works as an energy absorption unit to store excess energy generated by the fuel cell 21; if the output power of the fuel cell 21 is less than the load demand, the lithium battery 31 works as an energy supplement unit, sharing the power supply with the fuel cell 21.

[0067] The power management module 32 is responsible for the conversion, distribution, and transmission of electrical energy, ensuring that the electrical energy output from the fuel cell 21 and the lithium battery 31 has a stable voltage platform. This enables the two to be reliably combined and meet the power demand of the power generation system load.

[0068] The energy management system 4 is responsible for implementing the above-mentioned energy management and control methods. Specifically, it acquires the SOC status of the lithium battery 31, the set value of the lithium battery 31 current, and the measured value of the lithium battery 31 current in real time through the CAN bus. Based on the SOC status of the lithium battery 31, it controls whether the fuel cell 21 enters the working mode or the sleep mode. At the same time, the energy management system 4 also executes a PID control algorithm with the lithium battery 31 current as the control target and sends instructions to the fuel cell 21 output control module to achieve precise power allocation and tracking.

[0069] This embodiment also provides a fuel cell energy management and control device, such as... Figure 3 As shown, it includes a memory 5 and a processor 6, wherein the memory 5 is used to store computer programs and data; the processor 6 is used to implement the steps of the above-described fuel cell energy management and control method when executing the computer program.

[0070] The above description is merely a preferred embodiment of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principles of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. A fuel cell energy management and control method, characterized in that, Includes the following steps: Step S1: Obtain the SOC status of lithium battery (31), the set value of lithium battery (31) current and the measured value of lithium battery (31) current through the CAN bus; Step S2: Determine the power supply state of fuel cell (21) based on the SOC state of lithium battery (31); if satisfied, fuel cell (21) enters working mode, and dynamically controls the output and proportion of fuel cell (21) according to the current set value and measured value of lithium battery (31), so that fuel cell (21) and lithium battery (31) work together to supply power to the load of power generation system; if not satisfied, fuel cell (21) enters dormant mode, and lithium battery (31) supplies power to the load of power generation system independently; In step S2, the difference between the measured value and the set value of the lithium battery (31) current is used as the control input. After the target output current of the fuel cell system (2) is generated by the PID control algorithm, it is input to the fuel cell output control module (22) to control the output power of the fuel cell (21). The process of generating the target output current of the fuel cell system (2) is as follows: Step S21, using the measured value of the lithium battery (31) current. With set value The difference between them is used as a control input, and its expression is: Step S22, adjust the current deviation of the lithium battery (31) As input, the target output current of the fuel cell system (2) is generated, and its expression is: In the formula, It is a time variable; This is the proportionality coefficient; The integral coefficient; These are the differential coefficients; The target output current for the fuel cell system (2); Indicates the current deviation of the lithium battery (31) Accumulated amount over time; Indicates the current deviation of the lithium battery (31) The rate of change.

2. The fuel cell energy management and control method according to claim 1, characterized in that, During the process of the fuel cell (21) and lithium battery (31) working together to supply power, the working state of lithium battery (31) is adjusted according to the output power of fuel cell (21): when the output power of fuel cell (21) is greater than or equal to the load demand, lithium battery (31) works as an energy absorption unit; when the output power of fuel cell (21) is less than the load demand, lithium battery (31) works as an energy replenishment unit.

3. A fuel cell energy management and control system for implementing the method of claim 1, characterized in that, The system includes: A hydrogen storage system (1) is used to generate hydrogen for the fuel cell (21); The fuel cell system (2) includes a fuel cell (21) and a fuel cell (21) output control module. The fuel cell (21) directly converts chemical energy into electrical energy through the electrochemical reaction of hydrogen and oxygen, supplying power to the load of the power generation system and charging the lithium battery (31). The fuel cell output control module (22) receives instructions from the energy management system (4), and through a PID control algorithm, calculates and issues a target output current command in real time based on the difference between the measured value and the set value of the lithium battery (31) current, so that the output of the fuel cell (21) can accurately track the load power demand of the power generation system. The power system (3) includes a lithium battery (31) and a power management module (32). The lithium battery (31) supplies power to the load of the power generation system and stores excess electrical energy generated by the fuel cell (21). The power management module (32) is responsible for the conversion, distribution and transmission of electrical energy, ensuring that the electrical energy output by the fuel cell (21) and the lithium battery (31) can be reliably combined and meet the power requirements of the load of the power generation system. The energy management system (4) is used to acquire the SOC status of the lithium battery (31), the set value of the lithium battery (31) current and the measured value of the lithium battery (31) current in real time, and control the operation mode of the fuel cell (21) based on the SOC status of the lithium battery (31). At the same time, it executes the PID control algorithm with the lithium battery (31) current as the control target, and sends instructions to the output control module of the fuel cell (21) to achieve precise power distribution and following.

4. A fuel cell energy management and control device, characterized in that, include: Memory (5) is used to store computer programs and data; The processor (6) is used to execute a computer program to implement the steps of the fuel cell energy management control method as described in any one of claims 1-2.

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