An energy distribution method and system for an off-grid hydrogen fuel cell charging pile system

Abstract

This invention discloses an energy distribution method and system for an off-grid hydrogen fuel cell charging pile system, relating to the field of fuel cell technology. When the surplus power is greater than zero, if the state of charge (SOC) of the power battery is less than a first threshold, the power battery is charged using the surplus photovoltaic power. If the power battery SOC is within the range of the first and third thresholds, hydrogen is produced using the surplus photovoltaic power. When the surplus power is not greater than zero, if the power to be supplemented is less than or equal to the minimum output power of the fuel cell and the power battery SOC is within the range of the first and third thresholds, the power battery provides the power to be supplemented. When the power battery SOC is less than or equal to the first threshold, the sum of the power to be supplemented and the power battery charging power is used as the output power to control the fuel cell startup. This optimized energy management strategy improves the overall energy utilization rate of the charging station.

Description

Technical Field

[0001] This invention relates to the field of fuel cell technology, and in particular to an energy distribution method and system for an off-grid hydrogen fuel cell charging station system. Background Technology

[0002] To address the high costs of grid reconstruction in off-grid scenarios or existing scenarios, renewable energy sources such as photovoltaics and hydrogen energy are currently being used to solve the charging problem for electric vehicles in off-grid environments. However, photovoltaic systems, as a renewable energy source, are intermittent and unstable. Their power output is affected by various factors such as weather conditions, geographical location, and time variations, which to some extent limits their power supply capacity and reliability.

[0003] Existing off-grid charging solutions mainly combine renewable energy power generation with energy storage systems. Some studies have provided control systems and methods based on multi-energy complementarity of renewable energy power generation; however, this solution uses fixed hydrogen storage tanks, which cannot be refueled once the hydrogen is depleted, making it difficult to meet the long-term operation requirements in off-grid scenarios, especially during continuous rainy days or when sunlight is insufficient in winter, when the system's continuous power supply capacity is limited.

[0004] One study proposed a DC interconnected microgrid system for wind, solar, hydro, and hydrogen storage fuel cells that can be connected to or disconnected from the grid. While this solution employs a DC bus architecture, it lacks a specific energy management strategy designed for off-grid charging scenarios. In actual operation, the intermittency and instability of photovoltaic power generation, along with the uncertainty of charging pile load demands, lead to low overall system efficiency, potential curtailment of solar power, and low energy utilization.

[0005] Furthermore, traditional off-grid power supply systems often use gas turbines as backup power sources. However, the energy conversion efficiency of gas turbines is typically only 30%-40%, with startup times lasting several minutes and slow response times, making it difficult to meet the demands of rapidly changing charging pile loads. Additionally, traditional solutions often employ a multi-stage DC-AC-DC energy conversion architecture, with energy losses occurring at each stage, resulting in low station-level operating efficiency and requiring multiple inverters, increasing system costs. Summary of the Invention

[0006] To address the aforementioned issues, this invention proposes an energy distribution method and system for off-grid hydrogen fuel cell charging piles. By optimizing energy management strategies, the energy utilization rate of the entire station is improved, enabling stable and efficient power supply to the charging piles in off-grid scenarios and resolving the instability problem of photovoltaic power generation.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: In a first aspect, the present invention provides an energy distribution method for an off-grid hydrogen fuel cell charging pile system, comprising: When the photovoltaic surplus power is greater than zero, if the power battery SOC is less than or equal to the first threshold, the photovoltaic surplus power is used as the charging power for the power battery until the power battery SOC reaches the second threshold; if the power battery SOC is within the range of the first and third thresholds, the photovoltaic surplus power is used as the hydrogen production power for hydrogen production until the main and auxiliary hydrogen cylinder pressures reach the rated full pressure; if the power battery SOC exceeds the fourth threshold, the photovoltaic output power is adjusted to balance the load demand of the charging pile; wherein, the second threshold is less than the third threshold, and the third threshold is less than the fourth threshold. When the surplus photovoltaic power is not greater than zero, if the power to be supplemented is less than or equal to the minimum output power of the fuel cell, and the SOC of the power battery is within the range of the first threshold and the third threshold, the power battery provides the power to be supplemented until the SOC of the power battery is less than or equal to the first threshold. Then, the sum of the power to be supplemented and the charging power of the power battery is used as the output power of the fuel cell to control the start of the fuel cell until the SOC of the power battery exceeds the fourth threshold, at which point the fuel cell is controlled to shut down.

[0008] As an alternative implementation method, when the power battery is being charged, if the charging power of the power battery is greater than the maximum charging power of the power battery, then the maximum charging power of the power battery shall be used as the charging power of the power battery. When the SOC of the power battery exceeds the fourth threshold, the sum of the photovoltaic power generation and the power battery charging power is the power required by the charging pile. The photovoltaic power generation maintains the load demand of the charging pile, and the remaining energy is supplemented by the power battery. The power battery retains 5% of its charge to provide the required power when the fuel cell is shut down.

[0009] As an alternative implementation method, after the fuel cell starts, the output power of the fuel cell meets the load requirements of the charging pile and charges the power battery. When the state of charge (SOC) of the power battery reaches the range between the first and third thresholds, the output power of the fuel cell is adjusted to the power to be supplemented, and the power battery is no longer charged. When the SOC of the power battery exceeds the fourth threshold, the fuel cell is controlled to shut down, and the power to be supplemented is provided by the power battery.

[0010] As an alternative implementation method, during the hydrogen production process, if the hydrogen production power is greater than the rated power of the hydrogen production system, then the rated power of the hydrogen production system shall be used as the hydrogen production power; if the hydrogen production power is less than the minimum power of the hydrogen production system, then hydrogen production shall be stopped.

[0011] As an alternative implementation method, the process of controlling the hydrogen production rate during hydrogen production includes: With surplus photovoltaic power As hydrogen production power Hydrogen production; Calculate the rate of change of SOC: ; Determine the reference power for hydrogen production ; Adjust the hydrogen production baseline power based on the SOC change rate. Adjusted hydrogen production capacity for: ; Calculate the maximum allowable power change per sampling period : ; Based on the adjusted hydrogen production power, through the saturation function After limiting the amplitude, the intermediate power is obtained: ; A smoothing of hydrogen production power is achieved through first-order inertial filtering: ; The smoothed final hydrogen production power is converted into load current. : The hydrogen production rate can be kept constant by adjusting the load current of the electrolyzer. in, for Constant state of charge of the power battery; for Constant state of charge of the power battery; The sampling period; Rated power of the hydrogen production system; The proportional coefficient for adjusting the rate of change of SOC; for Final hydrogen production power after time smoothing; for Hydrogen production power after time-smoothing; These are the coefficients of the first-order inertial filter; This represents the intermediate power after slope limiting. This represents the maximum permissible rate of change in hydrogen production capacity. This is the rated operating voltage of the electrolytic cell; for Hydrogen production capacity adjusted over time; for Hydrogen production capacity after real-time adjustment.

[0012] As an alternative implementation, the process of controlling the hydrogen production rate during hydrogen production also includes: Both the main hydrogen cylinder and the auxiliary hydrogen cylinder are connected to the high-pressure buffer tank. The high-pressure buffer tank is connected to the compressor system. The compressor system is connected to the hydrogen production system through the low-pressure buffer tank. Based on the pressure setting value of the high-pressure buffer tank and Calculate the pressure deviation by the pressure difference in the high-pressure buffer tank at any given time. The compressor output frequency is determined by PID control based on the pressure deviation. : For compressor output frequency Feedforward compensation for valve group switching: , ; in, for The compressor output frequency after time-compensation; The coefficient of variation; for Pressure changes during valve group switching; for Constantly compensate for changes; for The compressor output frequency at any given time.

[0013] As an alternative implementation method, during the hydrogen production process, the pressure of the main hydrogen cylinder is determined. Is it less than the rated full pressure of the main hydrogen cylinder? Or the pressure of the auxiliary hydrogen cylinder Is it less than the rated full pressure of the auxiliary hydrogen cylinder? ; like Then the hydrogen is stored in the main hydrogen cylinder until... achieve At that time, the main hydrogen tank is full; like and If the hydrogen cylinder switching operation is not performed, the hydrogen will be switched to an auxiliary hydrogen cylinder for storage until... achieve At that time, the auxiliary hydrogen tank was full; like and If both bottles are full, hydrogen production will stop.

[0014] As an alternative implementation method, the main hydrogen tank pressure is monitored in real time after the fuel cell is started. and auxiliary hydrogen cylinder pressure And determine the main hydrogen cylinder pressure. Is it less than the minimum pressure of the main hydrogen cylinder? And the auxiliary hydrogen cylinder pressure Is it greater than the minimum pressure of the auxiliary hydrogen cylinder? ; like and If the main hydrogen cylinder pressure is insufficient, switch between the main and auxiliary hydrogen cylinders. like and If the auxiliary hydrogen cylinder pressure is insufficient, switch between the auxiliary and main hydrogen cylinders. like and If the system detects insufficient pressure in both cylinders, it will issue a reminder to replace the hydrogen cylinder.

[0015] As an alternative implementation method, the hydrogen cylinder switching process includes: Both the main hydrogen cylinder and the auxiliary hydrogen cylinder are connected to the high-pressure buffer tank. The high-pressure buffer tank is connected to the compressor system. The compressor system is connected to the hydrogen production system through the low-pressure buffer tank. A main valve V01 is installed between the high-pressure buffer tank and the main hydrogen cylinder, and an auxiliary valve V02 is installed between the high-pressure buffer tank and the auxiliary hydrogen cylinder. A pressure equalization valve V03 is installed between the end of the main valve V01 connected to the main hydrogen cylinder and the end of the auxiliary valve V02 connected to the auxiliary hydrogen cylinder. When switching hydrogen cylinders, the equalizing valve V03 is opened, and the pressure in the main manifold is synchronously transmitted to the auxiliary hydrogen cylinder branch through the equalizing valve V03. When the pressure difference between the main hydrogen cylinder and the auxiliary hydrogen cylinder is less than or equal to the preset pressure difference threshold, the valve group linkage switching is initiated. First, the main valve V01 is kept open, and the auxiliary valve V02 is linearly opened to establish a flow channel for the auxiliary hydrogen cylinder. Then, the opening of the auxiliary valve V02 is continuously and linearly increased, while the opening of the main valve V01 is synchronously and linearly decreased to maintain a stable flow in the main manifold. When the opening of the auxiliary valve V02 reaches the normal operating opening, the main valve V01 is completely closed, completing the switching.

[0016] Secondly, the present invention provides an energy distribution system for an off-grid hydrogen fuel cell charging pile system, comprising a control system and an off-grid hydrogen fuel cell charging pile system that communicate with each other; the off-grid hydrogen fuel cell charging pile system includes a photovoltaic system connected to a DC bus, a hydrogen production system, a fuel cell, and a power battery; The control system is configured as follows: When the surplus photovoltaic power is greater than zero, if the SOC of the power battery is less than or equal to the first threshold, the surplus photovoltaic power is used as the charging power for the power battery until the SOC of the power battery reaches the second threshold; if the SOC of the power battery is within the range of the first and third thresholds, the surplus photovoltaic power is used as the hydrogen production power for hydrogen production until the main and auxiliary hydrogen cylinder pressures reach the rated full pressure; if the SOC of the power battery exceeds the fourth threshold, the photovoltaic output power is adjusted to balance the load demand of the charging pile. Among them, the second threshold is less than the third threshold, and the third threshold is less than the fourth threshold; When the surplus photovoltaic power is not greater than zero, if the power to be supplemented is less than or equal to the minimum output power of the fuel cell, and the SOC of the power battery is within the range of the first threshold and the third threshold, the power battery provides the power to be supplemented until the SOC of the power battery is less than or equal to the first threshold. Then, the sum of the power to be supplemented and the charging power of the power battery is used as the output power of the fuel cell to control the start of the fuel cell until the SOC of the power battery exceeds the fourth threshold, at which point the fuel cell is controlled to shut down.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention proposes an energy distribution method and system for an off-grid hydrogen fuel cell charging pile system. The overall scheme adopts a DC architecture, reducing energy conversion levels, improving station-level operating efficiency, reducing the number of inverters, and lowering costs. Fuel cells are introduced because of their stable power generation capability, releasing electrical energy during periods of insufficient sunlight or peak charging pile demand, thereby achieving optimized scheduling and balance of power supply. A power battery is introduced to provide high-voltage starting power for the fuel cells, balancing the dynamic fluctuations in charging pile demand. A hydrogen production system is introduced to store excess electrical energy during peak photovoltaic power generation periods, converting it into hydrogen and storing it in main and auxiliary hydrogen cylinders, solving the off-grid system's energy replenishment problem and achieving energy supply in off-grid scenarios. Based on the analysis of the operating characteristics of each device, a reasonable energy management method is formulated for off-grid scenarios. Under limited conditions, the photovoltaic system outputs at maximum capacity, and hydrogen energy regulation maintains the stable output of the downstream charging piles, optimizing system energy flow and improving the overall station's energy utilization rate.

[0018] Advantages of additional aspects of the invention 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 the invention. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the overall architecture of the fuel cell charging pile system provided in Embodiment 1 of the present invention; Figure 2 This is a schematic diagram of the overall architecture of the off-grid hydrogen fuel cell charging pile system provided in Embodiment 1 of the present invention; Figure 3 This is a schematic diagram showing the connection between the hydrogen production system, the compressor system, and the hydrogen storage system provided in Embodiment 1 of the present invention; Figure 4 The flowchart shows the energy distribution method of the off-grid hydrogen fuel cell charging pile system provided in Embodiment 1 of the present invention. Detailed Implementation

[0021] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0022] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0023] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, unless the context clearly indicates otherwise, the singular form is intended to include the plural form as well. Furthermore, it should be understood that the terms “comprising” and “including”, and any variations thereof, are intended to cover non-exclusive inclusion, for example, a process, method, system, product, or apparatus that includes a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0024] Where there is no conflict, the embodiments and features in the embodiments of the present invention can be combined with each other.

[0025] Example 1 like Figure 1 As shown, this embodiment provides a fuel cell charging pile system, including a fuel cell, a power battery, a charging pile, a UPS (Uninterruptible Power Supply), a DC-AC inverter, a first DC-DC converter, a second DC-DC converter, and a third DC-DC converter.

[0026] Each component is connected to the DC bus via a DC-DC converter. The DC bus serves as the foundation of the system's electrical architecture and is connected via copper busbars to ensure low-loss power transmission between the components.

[0027] The fuel cell is electrically connected to the DC bus via a first DC-DC converter, and generates electricity from the fuel cell to supply power to the charging station.

[0028] The power battery is electrically connected to the DC bus via a second DC-DC converter. The power battery is responsible for building and stabilizing the DC bus voltage for fuel cell startup, rapid response to changes in charging station demand, and has a reserved DC interface for easy integration with external photovoltaic systems. The power battery is equipped with a Battery Management System (BMS) that monitors the voltage, temperature, and SOC (State of Charge) of each individual cell in real time and communicates with the control system via a CAN bus.

[0029] The UPS is electrically connected to the DC bus, the DC-AC inverter is electrically connected to the DC bus, and the charging station is electrically connected to the DC bus via a third DC-DC converter. The charging station includes multiple charging modules, each equipped with multiple charging guns.

[0030] In addition, the system is also configured to power internal loads such as internal fans and lighting, as well as external loads such as external compressor systems, through DCAC inverters; and to power key low-voltage components such as control systems and fire protection systems through UPS, with the UPS replenishing internal energy through the DC bus.

[0031] like Figure 2 As shown, based on the fuel cell charging pile system, an off-grid hydrogen fuel cell charging pile system is further provided, which adds a photovoltaic system, a hydrogen production system, a compressor system, a hydrogen storage system, a fourth DC-DC converter, and a fifth DC-DC converter.

[0032] The photovoltaic system is electrically connected to the DC bus via the fourth DC-DC converter; the hydrogen production system is electrically connected to the DC bus via the fifth DC-DC converter; and the compressor system is electrically connected to the DC-AC inverter via the AC bus to draw power from the DC bus through the DC-AC inverter.

[0033] The photovoltaic system and fuel cell form an off-grid power source to charge the charging piles. Excess electricity is converted into hydrogen through a hydrogen production system and then pumped into a hydrogen storage system through a compressor system.

[0034] The hydrogen storage system includes a mobile cylinder group, consisting of a main hydrogen cylinder and an auxiliary hydrogen cylinder. When sunlight is insufficient, fuel is replenished through the mobile cylinder group. When there is a surplus of photovoltaic power, the generated hydrogen is stored in the mobile cylinder group for inter-station distribution or hydrogen sales, thus achieving seasonal storage.

[0035] Therefore, based on the aforementioned off-grid hydrogen fuel cell charging pile system architecture, this embodiment provides an energy distribution method for the off-grid hydrogen fuel cell charging pile system. In scenarios with sufficient sunlight, multi-level mode switching enables the orderly consumption of surplus photovoltaic power, avoiding solar power curtailment. When sunlight is insufficient, switching between fuel standby mode and fuel cell output mode ensures efficient operation of the fuel cell and rational utilization of hydrogen energy. Simultaneously, the main and auxiliary hydrogen cylinder switching logic guarantees the continuity of hydrogen supply.

[0036] The following is combined Figure 3 This method will be explained in detail.

[0037] Specifically: 1. When the photovoltaic power exceeds the load demand, the hydrogen production system and its associated compressor system are activated to produce hydrogen through water electrolysis. The compressor system pressurizes the hydrogen and stores it in hydrogen cylinders. Based on the surplus photovoltaic power and the state of charge (SOC) of the power battery, the power battery SOC is kept within the normal operating range (e.g., 20%~90%). When the power battery SOC is less than or equal to 20%, the second DC-DC converter controls the power battery to charge. Once the SOC reaches the set value (e.g., 50%), the control system adjusts the hydrogen production rate. When the main hydrogen cylinder is fully pressurized, the valve group switches to pressurize the auxiliary hydrogen cylinder. After the auxiliary hydrogen cylinder is full, the hydrogen production system and compressor system stop. The remaining photovoltaic power charges the power battery. When the power battery is 95% charged, the fourth DC-DC converter adjusts the photovoltaic output power to balance the load demand. The power battery retains 5% charge for normal fuel cell shutdown. In this scenario, the power balance equation is: .

[0038] 2. When sunlight is insufficient, the photovoltaic system maintains maximum MPPT power output and checks if the power to be supplemented is greater than the minimum output power of the fuel cell. If it is less than or equal to the minimum output power of the fuel cell and the SOC of the power battery is within the normal range, the fuel cell is under high voltage and enters a high-voltage standby state, awaiting a start command. At this time, the power to be supplemented is supplied by the power battery, and the output of the power battery is controlled by the second DC-DC converter. When the SOC of the power battery is less than or equal to 20%, a fuel cell start command is issued, and the fuel cell starts supplying hydrogen. The output power of the fuel cell is adjusted by the first DC-DC converter, and the fuel cell outputs power to the DC bus. The output power is the power to be supplemented plus the charging power of the power battery, which is used to supply the charging pile load. The power battery is also charged by the second DC-DC converter. When the SOC of the power battery is higher than 95%, the fuel cell starts to shut down and enters a high-voltage standby state after shutdown, preparing for the next start. In this scenario, the power balance equation is: .

[0039] The above strategy specifically includes the following steps: S1: The control system is powered on and started, initializing the communication interfaces of each subsystem and setting control parameters.

[0040] Control parameters include: power battery SOC threshold (first threshold) Second threshold The third threshold The fourth threshold ); Hydrogen cylinder pressure threshold (rated full pressure of main hydrogen cylinder) The rated full pressure of the auxiliary hydrogen cylinder Minimum pressure of the main hydrogen cylinder Minimum pressure of auxiliary hydrogen cylinder ); Rated power of hydrogen production system ( ), minimum power of hydrogen production system ( ), sampling period Control cycle .

[0041] S2: The control system collects the operating parameters of each subsystem in real time via the CAN bus, including: photovoltaic power generation. (Reported via the fourth DC-DC converter), charging station power demand. (Reported via a third DC-DC converter), system power loss (Calculated via DC bus current sensor), SOC of power battery (reported via power battery BMS), and main hydrogen tank pressure. (Measured by a pressure sensor) Auxiliary hydrogen cylinder pressure (Measured by a pressure sensor) Fuel cell operating status (Reported via fuel cell controller), hydrogen production system power Operating status of hydrogen production system (Reported via the hydrogen production system controller). The sampling period is 1 second, and the sampled data is stored in the control system's data buffer.

[0042] S3: Based on photovoltaic power generation Power requirements of charging piles Calculate the surplus power of photovoltaic power .

[0043] if If the scene is determined to be well-lit, proceed to step S4. if If the scene is determined to be under-lit, proceed to step S5.

[0044] S4: When photovoltaic power is sufficient, four operating modes are defined based on the direction of power flow.

[0045] Specifically: S4-1: Determine whether the SOC of the power battery is less than or equal to the first threshold. (20%). If the power battery If the battery power is determined to be insufficient, it needs to be charged first, executing the low SOC charging priority mode; if If the power battery charge is determined to be normal, proceed to step S4-2.

[0046] SOC low-limit charging priority mode performs the following operations: (1) Stop the hydrogen production system. If the hydrogen production system is currently in operation ( If the input power is insufficient, a stop command is sent to the hydrogen production system. The hydrogen production system executes the stop procedure, gradually reducing the input power until... After the shutdown is complete, the hydrogen production system enters standby mode. ).

[0047] (2) Stop the compressor system. The control system sends a stop command to the DCAC inverter, the DCAC inverter stops supplying power to the compressor system, and the compressor system stops running.

[0048] (3) Power battery charging. Using surplus photovoltaic power... As the charging power of the power battery ,Right now And determine the charging power of the power battery. Is it greater than the maximum charging power of the power battery? ,if Then let .

[0049] The charging power of the power battery is adjusted by a second DC-DC converter to make it follow Furthermore, the second DC-DC converter adopts a constant current charging mode.

[0050] (4) Monitor the SOC of the power battery in real time. When the SOC of the power battery reaches the second threshold, ( When the SOC low-limit charging priority mode ends, it is determined that the charging priority mode has ended.

[0051] S4-2: Determine if the SOC of the power battery is within the first threshold. (20%) and the third threshold (90%) .

[0052] if Then determine the main hydrogen cylinder pressure. Is it lower than the rated full pressure of the main hydrogen cylinder? Or the pressure of the auxiliary hydrogen cylinder Is it lower than the rated full pressure of the auxiliary hydrogen cylinder? .if or If the hydrogen tank is not full, hydrogen production is required, and the system enters hydrogen production priority mode until... and Once both bottles are full, hydrogen production stops and the system enters charging mode.

[0053] if If the battery has sufficient charge, the hydrogen production stage can be skipped.

[0054] In hydrogen production priority mode, the following operations are performed: (1) Start the hydrogen production system. If the hydrogen production system is currently in standby mode ( If the command is executed, a start command is sent to the hydrogen production system. The hydrogen production system executes the start-up procedure, and after startup, the hydrogen production system enters the operating state. ).

[0055] (2) Start the compressor system. The control sends a start command to the DCAC inverter, the DCAC inverter supplies power to the compressor system, and the compressor system starts running.

[0056] (3) Using surplus photovoltaic power As power of hydrogen production systems ,Right now Simultaneously, determine the power output of the hydrogen production system. Is it greater than the rated power of the hydrogen production system? If so... Then let ,if If the hydrogen production system fails, the hydrogen production system will be stopped. The input power of the hydrogen production system will be adjusted via the fifth DC-DC converter to match the output power. .

[0057] Real-time monitoring of main hydrogen cylinder pressure and auxiliary hydrogen cylinder pressure ,if Hydrogen is stored in the main hydrogen cylinder until... achieve At that time, the main hydrogen tank is full.

[0058] Then determine the pressure of the auxiliary hydrogen cylinder. Is it less than the rated full pressure of the auxiliary hydrogen cylinder? ,if and The switching operation is performed, and the hydrogen is switched to the auxiliary hydrogen cylinder for storage until... achieve At that time, the auxiliary hydrogen cylinder was full.

[0059] if and If both bottles are full, hydrogen production will stop.

[0060] S4-3: Determine if the SOC of the power battery is less than the fourth threshold. (95%). If If so, then the energy storage mode will be executed.

[0061] Specifically: Shut down the hydrogen production system and compressor system (if they are currently operating). Utilize surplus photovoltaic power. As the charging power of the power battery ,Right now And determine the charging power of the power battery. Is it greater than the maximum charging power of the power battery? ,if Then let .

[0062] The charging power of the power battery is adjusted by a second DC-DC converter to make it follow Real-time monitoring of the power battery's SOC. When the SOC reaches... The energy storage mode ends when (95%).

[0063] S4-4: When the SOC of the power battery is greater than the fourth threshold When the power consumption is 95%, the photovoltaic power curtailment mode is implemented.

[0064] Specifically: Calculate the power required for charging piles Once the power battery is fully charged, the photovoltaic power is adjusted to only maintain the load demand of the charging pile; transient fluctuations are compensated by the power battery. The power battery retains 5% of its charge (i.e., and (The capacity between) is used to provide the necessary electrical energy when the fuel cell is safely shut down.

[0065] In this embodiment, under sufficient sunlight, the orderly consumption of surplus photovoltaic power is achieved through a tiered switching of four modes: SOC low-limit charging priority, hydrogen production priority, electric energy storage, and photovoltaic power limiting, thereby avoiding the phenomenon of curtailment and improving energy utilization.

[0066] S5: Real-time acquisition of operating parameters of each subsystem, including photovoltaic power generation. Power requirements for charging piles System power loss Power battery SOC, main hydrogen tank pressure auxiliary hydrogen cylinder pressure Fuel cell operating status and fuel cell output power .

[0067] When the photovoltaic surplus power is less than or equal to zero, the photovoltaic system operates in maximum power point tracking (MPPT) mode to ensure that the photovoltaic system outputs at its maximum capacity.

[0068] Calculate the power to be supplemented .

[0069] S6: If power needs to be replenished Less than or equal to the minimum output power of the fuel cell And the power battery SOC is (20%) and If the percentage is between 90% and 90%, the fuel cell system is kept in standby mode. Power to be replenished All powered by the battery, i.e. .

[0070] S7: When the SOC of the power battery is less than or equal to When the battery level is 20%, it is determined that the power battery is low and the fuel cell needs to be started to enter the fuel cell output mode; otherwise, the fuel standby mode or the current operating mode is executed.

[0071] The fuel cell output mode performs the following operations: (1) If the fuel cell system is currently in standby mode ( The system sends a start command to the fuel cell system. The fuel cell system executes the start-up procedure, and after startup, the fuel cell system enters the operating state. ).

[0072] (2) Calculate the output power of the fuel cell .

[0073] If the power battery ,but This means that the fuel cell output power must meet both the load demand and charge the power battery. The fuel cell output power follows the charging pile load demand in real time, and the output power is constrained within the rated range. , Within the maximum output power of the fuel cell, the difference in power is compensated by the power battery.

[0074] (3) Determine whether the SOC of the power battery is within the specified range. (20%) and (90%). If so, determine that the power battery charge has returned to normal and adjust the fuel cell output power. It will no longer charge the power battery.

[0075] S8: If the SOC of the power battery is greater than... (95%), then the power to be supplemented Powered by the battery, i.e. And because the fuel cell is currently in operation ( If the shutdown operation is completed, the fuel cell system will enter standby mode. The load is switched to photovoltaic and power battery power supply mode.

[0076] S9: Real-time monitoring of main hydrogen cylinder pressure and auxiliary hydrogen cylinder pressure It will provide reminders for switching and replacing the main and auxiliary hydrogen cylinders based on the gas pressure status.

[0077] Specifically: Determine the pressure of the main hydrogen cylinder Is it below the minimum pressure of the main hydrogen cylinder? (5MPa), and the auxiliary hydrogen cylinder pressure Is it higher than the minimum pressure of the auxiliary hydrogen cylinder? (5MPa).

[0078] if and If the main hydrogen cylinder pressure is insufficient, it is necessary to switch to the auxiliary hydrogen cylinder. The main / auxiliary hydrogen cylinder switchover is then executed, indicated by the hydrogen cylinder switchover flag. .

[0079] if and If the auxiliary hydrogen cylinder pressure is insufficient, it is necessary to switch to the main hydrogen cylinder. The auxiliary-to-main hydrogen cylinder switchover is executed, indicated by the hydrogen cylinder switchover flag. .

[0080] if and If the system detects insufficient pressure in both gas cylinders, it will issue a hydrogen cylinder replacement reminder. Otherwise, the hydrogen cylinder replacement reminder sign will be displayed. .

[0081] By rationally switching between fuel standby mode and fuel cell output mode, the lifespan of the fuel cell is extended, hydrogen consumption is reduced, and power supply reliability is improved. The main and auxiliary hydrogen cylinder switching logic ensures continuous hydrogen supply, enabling stable 24 / 7 power supply to charging stations in off-grid scenarios.

[0082] In this embodiment, as Figure 4 As shown, a low-pressure buffer tank is connected between the hydrogen production system and the compressor system, and a high-pressure buffer tank is connected between the compressor system and the hydrogen storage system. The high-pressure buffer tank is connected to the main hydrogen cylinder and the auxiliary hydrogen cylinder respectively. A main valve V01 is provided between the high-pressure buffer tank and the main hydrogen cylinder, and an auxiliary valve V02 is provided between the high-pressure buffer tank and the auxiliary hydrogen cylinder. One end of the main valve V01 is connected to the main hydrogen cylinder, and a pressure equalization valve V03 is provided between the end of the main valve V01 and the end of the auxiliary valve V02 connected to the auxiliary hydrogen cylinder.

[0083] Therefore, when switching between main and auxiliary gas cylinders, pressure buffering can be achieved through buffer tanks to reduce the impact on the upstream hydrogen production rate. Combined with the timing control of the downstream valve group, pressure equalization can be achieved. Through a multi-strategy collaborative scheme of upstream hydrogen production closed-loop regulation, downstream pressure closed-loop dynamic regulation, and feedforward compensation, a smooth switching of hydrogen cylinders can be achieved.

[0084] In normal operating mode, the main valve V01 is open, the main hydrogen cylinder branch is connected, the auxiliary valve V02 is closed, the auxiliary hydrogen cylinder branch is on standby, and the equalizing valve V03 is closed; when the pressure of the main hydrogen cylinder P1 reaches the rated full pressure of the main hydrogen cylinder, the switching process is started.

[0085] First, pre-pressure equalization is performed, specifically by opening the equalization valve V03. The pressure in the main manifold is then synchronously transmitted to the auxiliary hydrogen cylinder branch through the equalization valve V03 to gradually balance the pressure difference between the main and auxiliary cylinders. When the pressure difference between the main hydrogen cylinder and the auxiliary hydrogen cylinder is less than or equal to the preset pressure difference threshold, the valve group linkage switching is initiated.

[0086] Specifically as follows: (1) Pre-start of auxiliary hydrogen cylinder branch: Keep the main valve V01 open, slowly and linearly open the auxiliary valve V02 to establish the auxiliary hydrogen cylinder flow channel.

[0087] (2) Synchronous adjustment of main and auxiliary valves: linearly increase the opening of auxiliary valve V02 and synchronously and linearly decrease the opening of main valve V01 to maintain stable total flow.

[0088] (3) Switching of shut-off valve: When the opening of auxiliary valve V02 reaches the normal operating opening, the main valve V01 is completely closed, and the switching is completed.

[0089] In this embodiment, the specific control process of the hydrogen production rate during hydrogen production includes: 1. Stable upstream demand: The hydrogen production rate is related to the load current. The hydrogen production rate can be precisely controlled through closed-loop power regulation.

[0090] (1) Using surplus photovoltaic power As power of hydrogen production systems To produce hydrogen, that is When there is a surplus of photovoltaic power, the hydrogen production capacity of the electrolyzer can be increased to absorb the excess photovoltaic power; when the photovoltaic power is insufficient, the hydrogen production capacity should be reduced first to ensure a stable power supply for the charging piles.

[0091] (2) Calculate the rate of change of SOC This reflects the charging and discharging status of the power battery. ; in, for The state of charge of the power battery at any time is expressed in % (%). for The state of charge of the power battery at any time is expressed in % (%). The sampling period is expressed in seconds (s).

[0092] when The power battery is in a charging state, which can moderately increase the hydrogen production power; when When the power battery is in a discharging state, the hydrogen production power needs to be reduced to protect the energy storage system.

[0093] (3) Calculate the hydrogen production baseline power ;in, The rated power of the hydrogen production system is expressed in kW.

[0094] (4) Dynamically adjust the hydrogen production baseline power based on the SOC change rate. If photovoltaic-energy storage-hydrogen production coordinated control is achieved, the adjusted hydrogen production power will be: ; in, The adjusted hydrogen production capacity is expressed in kW. It is the proportional coefficient for correcting the rate of change of SOC, and belongs to the engineering tuning constant.

[0095] (5) By limiting the power slope, the sudden changes in hydrogen production rate and the pressure shock during the switching between the main and auxiliary hydrogen cylinders are avoided. Specifically, the adjusted hydrogen production power is used as the benchmark, and the saturation function is used to limit the power slope. Amplitude limiting is completed to obtain intermediate power. : ; ; in, The maximum allowable power variation per sampling period, in kW; The data collection period is expressed in seconds (s). The maximum permissible rate of change in hydrogen production power is expressed in kW / s. for Hydrogen production capacity adjusted over time; for Hydrogen production capacity after real-time adjustment.

[0096] (6) By using first-order inertial filtering, photovoltaic power fluctuations are further suppressed, thus smoothing the hydrogen production power: ; in, for The final hydrogen production power after time-smoothing, in kW; for Hydrogen production power after time-smoothing, in kW; These are the first-order inertial filter coefficients, with values ​​ranging from 0 to 1; for The intermediate power at any given time, expressed in kW.

[0097] (7) The smoothed final hydrogen production power is converted into load current, and the hydrogen production rate is precisely controlled by the current PID closed loop.

[0098] The load current is calculated as follows: ; in, This is the load current, expressed in amperes (A). The rated operating voltage of the electrolyzer is expressed in volts (V). By adjusting the load current of the electrolyzer, a constant hydrogen production rate can ultimately be achieved.

[0099] 2. Stable back-end pressure: Dynamic closed-loop control of compressor output pressure and feedforward regulation are coordinated.

[0100] There is a coupling relationship between the hydrogen production rate of the electrolyzer and the outlet back pressure: when the back pressure increases, the gas production decreases, and when the back pressure decreases, the gas production increases suddenly.

[0101] The control objectives include: maintaining a constant pressure in the high-pressure buffer tank; ensuring stable pressure in the low-pressure buffer tank; suppressing valve switching disturbances; and avoiding back pressure fluctuations in the electrolyzer. Throughout the process, the pressure fluctuations in the high-pressure buffer tank are controlled to meet the set requirements, ensuring a constant hydrogen production rate in the electrolyzer.

[0102] Specifically: (1) Calculate the pressure deviation: ; Where P1 is The pressure of the high-pressure buffer tank at any given time, in MPa; P 1set This is the pressure setpoint for the high-pressure buffer tank, in MPa.

[0103] (2) PID control: ; Among them, F Act F0 is the compressor output frequency, in Hz; F0 is the compressor reference frequency, in Hz. These are the proportional, integral, and derivative coefficients of the PID controller.

[0104] (3) The feedforward compensation for valve group switching is: ; ; in, for The compressor output frequency after time-compensation; The coefficient of variation; for Pressure changes during valve group switching; for Constantly compensate for changes; for The compressor output frequency at any given time.

[0105] Using PID closed-loop control as the main control loop, the compressor output frequency is adjusted, and feedforward compensation for valve group switching is increased. This allows for early prediction and frequency adjustment, suppressing pressure disturbances, ensuring stable pressure in the low-pressure buffer tank, and stabilizing the front-end hydrogen production rate.

[0106] Example 2 This embodiment provides an energy distribution system for an off-grid hydrogen fuel cell charging pile system, including a control system and an off-grid hydrogen fuel cell charging pile system that communicate with each other.

[0107] The off-grid hydrogen fuel cell charging pile system includes a photovoltaic system connected to the DC bus, a hydrogen production system, a fuel cell, and a power battery; it is understood that the off-grid hydrogen fuel cell charging pile system has been described in detail in Example 1, and will not be repeated here.

[0108] The control system is configured as follows: When the surplus photovoltaic power is greater than zero, if the SOC of the power battery is less than or equal to the first threshold, the surplus photovoltaic power is used as the charging power for the power battery until the SOC of the power battery reaches the second threshold; if the SOC of the power battery is within the range of the first and third thresholds, the surplus photovoltaic power is used as the hydrogen production power for hydrogen production until the main and auxiliary hydrogen cylinder pressures reach the rated full pressure; if the SOC of the power battery exceeds the fourth threshold, the photovoltaic output power is adjusted to balance the load demand of the charging pile. Among them, the second threshold is less than the third threshold, and the third threshold is less than the fourth threshold; When the surplus photovoltaic power is not greater than zero, if the power to be supplemented is less than or equal to the minimum output power of the fuel cell, and the SOC of the power battery is within the range of the first threshold and the third threshold, the power battery provides the power to be supplemented until the SOC of the power battery is less than or equal to the first threshold. Then, the sum of the power to be supplemented and the charging power of the power battery is used as the output power of the fuel cell to control the start of the fuel cell until the SOC of the power battery exceeds the fourth threshold, at which point the fuel cell is controlled to shut down.

[0109] Existing technologies using gas turbines are inefficient and have long start-up times. The above-described embodiment uses a fuel cell power generation system and a photovoltaic system as power sources, combined with a power battery to achieve off-grid operation of the charging pile and hydrogen production system. The entire system uses a DC architecture with low energy conversion efficiency, but it has advantages in terms of cost and efficiency.

[0110] Current off-grid photovoltaic energy storage solutions cannot meet the needs of long-term off-grid scenarios without sunlight and seasonal energy storage. The above-described embodiment adopts a hydrogen energy storage solution. The hydrogen cylinders are transportable and replaceable for refueling, and the off-grid output is provided by a fuel cell power generation system that converts hydrogen into electricity.

[0111] Current multi-energy energy management solutions suffer from energy waste, photovoltaic systems are unstable, and in off-grid scenarios, the energy consumption of back-end charging piles is uncertain, leading to deviations in overall station operating efficiency and instances of curtailment. The above-described implementation scheme considers multiple operating scenarios, utilizes the characteristics of each system, and formulates startup logic and operating plans to achieve optimal energy allocation across various scenarios.

[0112] The above embodiments provide an energy distribution method and system for off-grid hydrogen fuel cell charging piles, addressing the problems of low power supply efficiency, slow response, inability to refuel, and solar curtailment caused by photovoltaic instability in off-grid scenarios. The off-grid hydrogen fuel cell charging pile system adopts a DC architecture, reducing energy conversion levels (multi-stage energy conversion (DC-AC-DC) is replaced with DC-DC), improving station-level operating efficiency; it achieves energy replenishment in off-grid scenarios through photovoltaic hydrogen production / external hydrogen supply, and addresses photovoltaic instability by introducing a fuel cell system; based on the analysis of the operating characteristics of each device, a reasonable energy management method is formulated for off-grid scenarios, ensuring that the photovoltaic system outputs at maximum capacity under limited conditions, and maintaining stable output of the back-end charging piles through hydrogen energy regulation, optimizing system energy flow, and improving the overall station energy utilization rate.

[0113] While the specific embodiments of the present invention have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solutions of the present invention are still within the scope of protection of the present invention.

Claims

1. An energy distribution method for an off-grid hydrogen fuel cell charging pile system, characterized in that, include: When the photovoltaic surplus power is greater than zero, if the power battery SOC is less than or equal to the first threshold, the photovoltaic surplus power is used as the charging power for the power battery until the power battery SOC reaches the second threshold; if the power battery SOC is within the range of the first and third thresholds, the photovoltaic surplus power is used as the hydrogen production power for hydrogen production until the main and auxiliary hydrogen cylinder pressures reach the rated full pressure; if the power battery SOC exceeds the fourth threshold, the photovoltaic output power is adjusted to balance the load demand of the charging pile; wherein, the second threshold is less than the third threshold, and the third threshold is less than the fourth threshold. When the surplus photovoltaic power is not greater than zero, if the power to be supplemented is less than or equal to the minimum output power of the fuel cell, and the SOC of the power battery is within the range of the first threshold and the third threshold, the power battery provides the power to be supplemented until the SOC of the power battery is less than or equal to the first threshold. Then, the sum of the power to be supplemented and the charging power of the power battery is used as the output power of the fuel cell to control the start of the fuel cell until the SOC of the power battery exceeds the fourth threshold, at which point the fuel cell is controlled to shut down.

2. The energy distribution method for an off-grid hydrogen fuel cell charging pile system as described in claim 1, characterized in that, When the power battery is being charged, if the charging power of the power battery is greater than the maximum charging power of the power battery, then the maximum charging power of the power battery shall be used as the charging power of the power battery. When the SOC of the power battery exceeds the fourth threshold, the sum of the photovoltaic power generation and the power battery charging power is the power required by the charging pile. The photovoltaic power generation maintains the load demand of the charging pile, and the remaining energy is supplemented by the power battery. The power battery retains 5% of its charge to provide the required power when the fuel cell is shut down.

3. The energy distribution method for an off-grid hydrogen fuel cell charging pile system as described in claim 1, characterized in that, After the fuel cell starts, its output power meets the load requirements of the charging pile and charges the power battery. When the power battery's SOC reaches the range between the first and third thresholds, the fuel cell's output power is adjusted to the power to be supplemented, and it stops charging the power battery. When the power battery's SOC exceeds the fourth threshold, the fuel cell is shut down, and the power to be supplemented is provided by the power battery.

4. The energy distribution method for an off-grid hydrogen fuel cell charging pile system as described in claim 1, characterized in that, During hydrogen production, if the hydrogen production power is greater than the rated power of the hydrogen production system, the rated power of the hydrogen production system shall be used as the hydrogen production power; if the hydrogen production power is less than the minimum power of the hydrogen production system, hydrogen production shall be stopped.

5. The energy distribution method for an off-grid hydrogen fuel cell charging pile system as described in claim 4, characterized in that, In the hydrogen production process, the control of the hydrogen production rate includes: With surplus photovoltaic power As hydrogen production power To produce hydrogen; Calculate the rate of change of SOC: ; Determine the reference power for hydrogen production ; Adjust the hydrogen production baseline power based on the SOC change rate. Adjusted hydrogen production capacity for: ; Calculate the maximum allowable power change per sampling period : ; Based on the adjusted hydrogen production power, through the saturation function After limiting the amplitude, the intermediate power is obtained: ； A smoothing of hydrogen production power is achieved through first-order inertial filtering: ; The smoothed final hydrogen production power is converted into load current. : The hydrogen production rate can be kept constant by adjusting the load current of the electrolyzer. in, for Constant state of charge of the power battery; for Constant state of charge of the power battery; The sampling period; Rated power of the hydrogen production system; The proportionality coefficient for adjusting the rate of change of SOC; for Final hydrogen production power after time smoothing; for Hydrogen production power after time-smoothing; These are the first-order inertial filter coefficients; This represents the intermediate power after slope limiting. This represents the maximum permissible rate of change in hydrogen production capacity. This is the rated operating voltage of the electrolytic cell; for Hydrogen production capacity adjusted over time; for Hydrogen production capacity after real-time adjustment.

6. The energy distribution method for an off-grid hydrogen fuel cell charging pile system as described in claim 5, characterized in that, In the hydrogen production process, the control of the hydrogen production rate also includes: Both the main hydrogen cylinder and the auxiliary hydrogen cylinder are connected to the high-pressure buffer tank. The high-pressure buffer tank is connected to the compressor system. The compressor system is connected to the hydrogen production system through the low-pressure buffer tank. Based on the pressure setting value of the high-pressure buffer tank and Calculate the pressure deviation by the pressure difference in the high-pressure buffer tank at any given time. The compressor output frequency is determined by PID control based on the pressure deviation. : For compressor output frequency Feedforward compensation for valve group switching: ， ； in, for The compressor output frequency after time-compensation; The coefficient of variation; for Pressure changes during valve group switching; for Constantly compensate for changes; for The compressor output frequency at any given time.

7. The energy distribution method for an off-grid hydrogen fuel cell charging pile system as described in claim 1, characterized in that, During hydrogen production, the pressure of the main hydrogen cylinder is determined. Is it less than the rated full pressure of the main hydrogen cylinder? Or the pressure of the auxiliary hydrogen cylinder Is it less than the rated full pressure of the auxiliary hydrogen cylinder? ; like Then the hydrogen is stored in the main hydrogen cylinder until... achieve At that time, the main hydrogen tank is full; like and If the hydrogen cylinder switching operation is not performed, the hydrogen will be switched to an auxiliary hydrogen cylinder for storage until... achieve At that time, the auxiliary hydrogen tank was full; like and If both bottles are full, hydrogen production will stop.

8. The energy distribution method for an off-grid hydrogen fuel cell charging pile system as described in claim 1, characterized in that, After the fuel cell is started, the main hydrogen tank pressure is monitored in real time. and auxiliary hydrogen cylinder pressure And determine the main hydrogen cylinder pressure. Is it less than the minimum pressure of the main hydrogen cylinder? And the auxiliary hydrogen cylinder pressure Is it greater than the minimum pressure of the auxiliary hydrogen cylinder? ; like and If the main hydrogen cylinder pressure is insufficient, switch between the main and auxiliary hydrogen cylinders. like and If the auxiliary hydrogen cylinder pressure is insufficient, switch between the auxiliary and main hydrogen cylinders. like and If the system detects insufficient pressure in both cylinders, it will issue a reminder to replace the hydrogen cylinder.

9. The energy distribution method for an off-grid hydrogen fuel cell charging pile system as described in claim 7 or 8, characterized in that, The hydrogen cylinder switching process includes: Both the main hydrogen cylinder and the auxiliary hydrogen cylinder are connected to the high-pressure buffer tank. The high-pressure buffer tank is connected to the compressor system. The compressor system is connected to the hydrogen production system through the low-pressure buffer tank. A main valve V01 is installed between the high-pressure buffer tank and the main hydrogen cylinder, and an auxiliary valve V02 is installed between the high-pressure buffer tank and the auxiliary hydrogen cylinder. A pressure equalization valve V03 is installed between the end of the main valve V01 connected to the main hydrogen cylinder and the end of the auxiliary valve V02 connected to the auxiliary hydrogen cylinder. When switching hydrogen cylinders, the equalizing valve V03 is opened, and the pressure in the main manifold is synchronously transmitted to the auxiliary hydrogen cylinder branch through the equalizing valve V03. When the pressure difference between the main hydrogen cylinder and the auxiliary hydrogen cylinder is less than or equal to the preset pressure difference threshold, the valve group linkage switching is initiated. First, the main valve V01 is kept open, and the auxiliary valve V02 is linearly opened to establish a flow channel for the auxiliary hydrogen cylinder. Then, the opening of the auxiliary valve V02 is continuously and linearly increased, while the opening of the main valve V01 is synchronously and linearly decreased to maintain a stable flow in the main manifold. When the opening of the auxiliary valve V02 reaches the normal operating opening, the main valve V01 is completely closed, completing the switching.

10. An energy distribution system for an off-grid hydrogen fuel cell charging pile system, characterized in that, It includes a control system that communicates with each other and an off-grid hydrogen fuel cell charging pile system; the off-grid hydrogen fuel cell charging pile system includes a photovoltaic system connected to the DC bus, a hydrogen production system, a fuel cell, and a power battery; The control system is configured as follows: When the surplus photovoltaic power is greater than zero, if the SOC of the power battery is less than or equal to the first threshold, the surplus photovoltaic power is used as the charging power for the power battery until the SOC of the power battery reaches the second threshold; if the SOC of the power battery is within the range of the first and third thresholds, the surplus photovoltaic power is used as the hydrogen production power for hydrogen production until the main and auxiliary hydrogen cylinder pressures reach the rated full pressure; if the SOC of the power battery exceeds the fourth threshold, the photovoltaic output power is adjusted to balance the load demand of the charging pile. Among them, the second threshold is less than the third threshold, and the third threshold is less than the fourth threshold; When the surplus photovoltaic power is not greater than zero, if the power to be supplemented is less than or equal to the minimum output power of the fuel cell, and the SOC of the power battery is within the range of the first threshold and the third threshold, the power battery provides the power to be supplemented until the SOC of the power battery is less than or equal to the first threshold. Then, the sum of the power to be supplemented and the charging power of the power battery is used as the output power of the fuel cell to control the start of the fuel cell until the SOC of the power battery exceeds the fourth threshold, at which point the fuel cell is controlled to shut down.

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