Light-storage-hydrogen intelligent micro-grid management method

Abstract

The invention provides a light-storage-hydrogen intelligent micro-grid management method, and the method comprises the steps: recognizing the operation condition of a micro-grid based on real-time electricity price, energy storage real-time capacity and hydrogen storage reserve, and executing a system action according to the operation condition; outputting the power of each system in the microgrid under the identified operation condition according to an electricity price optimal model and a power balance model, and taking the output power of each system under the operation condition corresponding to the lowest value of the electricity price as configuration power; adjusting the current and / or voltage of a converter to enable each system in the alternating current coupling micro-grid to reach the configuration power calculated in the step S2; when the operation working condition is switched, an electricity price triggering criterion with a hysteresis interval is introduced as a working condition switching criterion; and when working condition switching is executed, a first-order inertia smoothing link and Ramp limited rate optimization power input are introduced. According to the technical scheme, the defects of an existing intelligent micro-grid management system in the aspects of management flexibility, economy, operation process and details are overcome, and the technical scheme is more detailed in low-light management.

Description

Technical Field

[0001] This application relates to the field of renewable energy utilization technology, specifically to a photovoltaic-storage-hydrogen smart microgrid management method. Background Technology

[0002] A microgrid, also known as a micro-network, is a small-scale power generation and distribution system comprised of distributed power sources, energy storage devices, energy conversion devices, related loads, and monitoring and protection devices. A smart microgrid is an independent system capable of self-control, protection, and management; it can operate in parallel with the external power grid or independently.

[0003] Currently, with the continuous increase in photovoltaic penetration, traditional microgrids relying solely on energy storage can no longer simultaneously address the three major issues of power fluctuations, short-term energy absorption, and long-term energy transfer. Electrolytic hydrogen production can achieve long-term energy storage and cross-seasonal applications, but it places higher demands on the real-time performance and reliability of the resulting "photovoltaic-battery-hydrogen storage-fuel cell-grid" system, including multi-stage power coordination, rapid AC bus voltage stabilization, and economically optimized operation. Existing management methods have shortcomings in many aspects: 1. The management methods lack flexibility and are not equipped with dynamic automatic division of operating conditions based on electricity prices, energy status, and real-time power shortage / surplus. 2. During the rapid switching instability process when the PV photovoltaic load is less than the load, the bus voltage and frequency deviate from the range of 380V±5% and 50Hz±0.5 Hz, respectively. 3. The power-energy difference between large-capacity energy storage devices and hydrogen production systems or fuel cells can lead to the curtailment of solar power and hydrogen production. 4. The economic optimization in management did not take into account the "electricity price - equipment life - hydrogen energy storage cycle opportunity benefits", resulting in insufficient details in the rough execution process of off-peak electricity energy storage, green electricity hydrogen production, and peak electricity off-grid discharge. Summary of the Invention

[0004] This application provides a photovoltaic-storage-hydrogen smart microgrid management method, which solves the shortcomings of existing smart microgrid management systems in terms of management flexibility, economy, operation process and details.

[0005] The technical solution of this application is as follows: A photovoltaic-storage-hydrogen smart microgrid management method is proposed. This method is based on an AC-coupled microgrid composed of photovoltaic (PV), lithium-ion battery (BESS), proton exchange membrane electrolyzer, fuel cell (FC), and mains power grid, and includes the following steps: S1. Identify the operating conditions of the AC-coupled microgrid based on real-time electricity price, real-time energy storage capacity, and hydrogen storage capacity, and execute system actions according to the operating conditions; S2. Output the power of each system in the AC-coupled microgrid under the identified operating conditions according to the optimal electricity price model and the power balance model, and use the output power of each system under the operating conditions corresponding to the lowest electricity price as the configuration power. S3. Adjust the current and / or voltage of the converter to enable each system in the AC-coupled microgrid to reach the configured power calculated in step S2; For step S3, when the operating condition changes: A price-triggered criterion with a hysteresis interval is introduced as a condition switching criterion; When performing a change of operating conditions: A first-order inertial smoothing element and a ramp-limited power input optimization are introduced.

[0006] Furthermore, in step S1, the AC-coupled microgrid includes eight operating conditions, and the identification criteria for these operating conditions are as follows: Operating condition 1: and ; Operating condition 2: and ; Operating condition 3: and ; Operating condition 4: ≤0.2 and ; Operating condition 5: and ; Operating condition 6: and ; Operating condition 7: or ; Operating condition 8: and ; In the above formula: Indicates real-time photovoltaic power; Indicates the real-time power of the load; Indicates the real-time capacity of electrochemical energy storage; Indicates the real-time hydrogen storage capacity; Indicates the maximum load capacity; Indicates real-time electricity price; This indicates a high electricity price. Indicates the threshold for real-time photovoltaic power change; Indicates the threshold for real-time load power change; Indicates the real-time voltage value; MAX represents the maximum voltage capacity; This indicates the maximum hydrogen storage capacity.

[0007] Furthermore, the actions performed in operating condition 1 are as follows: and The power difference is used to drive the proton exchange membrane (PEM) electrolyzer to produce hydrogen first, and if there is still a power difference, it is used to charge the lithium battery (BESS). The actions to be performed in operating condition 2 are as follows: and The power difference is used to drive the proton exchange membrane (PEM) electrolyzer to produce hydrogen first, and if there is still a power difference, it is sold to the external power grid. The action performed in operating condition 3 is: independent discharge of the lithium battery BESS to compensate. and The power difference; The action performed under operating condition 4 is: start fuel cell FC replenishment. and If the power difference cannot be made up, electricity will be purchased from the external power grid; The actions performed under operating condition 5 are as follows: stop the proton exchange membrane electrolyzer and supply power in the order of lithium battery BESS and external power grid. The operation in operating condition 6 is as follows: power is supplied in the order of lithium battery BESS, fuel cell FC, and external power grid. The execution action of operating condition 7 is as follows: power is supplied in the order of lithium battery BESS, fuel cell FC, and external power grid; among which, this execution action allows BESS to establish a step current; The actions performed under operating condition 8 are: shutting down the proton exchange membrane electrolyzer and forcing the photovoltaic (PV) to charge the lithium battery BESS; Alternatively, the proton exchange membrane (PEM) electrolyzer can be shut down, and the photovoltaic (PV) system can sell electricity to the external power grid.

[0008] Furthermore, the optimal electricity price model in step S2 is as follows: ; The power balance model in step S2 is as follows: ; In the above formula, This indicates the lowest possible electricity price. Indicates the unit price of electricity; Indicates the power at the grid connection point; Indicates the charging / discharging power of the energy storage battery; This represents the equivalent cost of battery discharge. This represents the equivalent cost of hydrogen storage discharge. This indicates the hydrogen production / discharge power of the hydrogen storage system.

[0009] Furthermore, the electricity price optimization model and power balance model in step S2 must satisfy the following constraints: ; ; ; ; ; ; ; In the above formula, Indicates the rated capacity of the photovoltaic system; and These represent the minimum and maximum power of the energy storage battery during charging / discharging, respectively. , These represent the maximum / minimum hydrogen production capacity allowed for hydrogen storage; Indicates the maximum available power purchase capacity of the external power grid; , These represent the minimum remaining capacity ratio and the maximum remaining capacity ratio of the battery, respectively. , These represent the maximum and minimum allowable charging / discharging power of the battery, respectively. Indicates battery charge / discharge efficiency; Indicates the optimization time step; "Don't" indicates the minimum hydrogen storage capacity.

[0010] Furthermore, the implementation method of introducing a price trigger criterion with a hysteresis interval as the operating condition switching criterion is as follows: SA1, Define the lower threshold for electricity price p LOW and upper threshold p UP : p LOW = ; p UP = ; In the formula, This indicates the threshold for determining electricity purchase eligibility. Indicates the hysteresis range of electricity prices; SA2, Define the initial state valley price condition S(k) = 0; SA3, Update State Judgment Function According to the judgment function The output result will trigger a switching action; ; In the formula, S(k−1) represents the previous state. This indicates the electricity price corresponding to the current state.

[0011] Furthermore, the first-order inertial smoothing element is based on the sampling period. accomplish: y[k]=y[k−1]+Δt / (t+Δt)(u[k]−y[k−1]); In the formula, u represents the original reference command, y represents the smoothed output power command, t represents the response speed parameter, and k represents the current cycle.

[0012] Furthermore, the ramp rate is based on the reference power command issued by the management system. accomplish: when hour, ; when hour, ; when hour, ; In the above formula, Indicates the reference power change value. ; Indicates the Ramp limit rate; This indicates a power control command issued by the control system; This indicates the power control command issued by the control system at the previous moment.

[0013] Due to the adoption of the above technical solution, the beneficial effects of this application are as follows: 1. This application first determines the operating conditions and then outputs the configured power after executing the action, which maximizes the self-sufficiency effect of the microgrid and provides the optimal solution from an economic perspective under this maximization premise. Specifically, this application provides 8 operating conditions and designs execution actions for 8 operating conditions. The execution action is the premise for achieving power balance. Under the premise of ensuring the self-sufficiency of the microgrid, the configured power with the lowest load price is given.

[0014] 2. This application implements a switching mechanism for AC-coupled microgrids based on electricity price, state of charge (SOC), hydrogen reserves, and power deficit, changing the traditional single switching mode of microgrids. Specifically, in eight operating conditions, each system executes switching actions based on operating condition criteria. In the operating condition switching criteria, this application innovatively introduces the concepts of equipment depreciation and hydrogen opportunity revenue, making power output more realistic and consistent with the actual operating scenarios of microgrids when calculating costs.

[0015] 3. This application effectively suppresses bus surges during switching. Specifically, by setting a hysteresis interval, it avoids "jittering" and frequent actions of operating conditions and commands during power purchase switching. It also avoids power spikes during operating condition switching by introducing a first-order inertial smoothing element. Since the control system issues a new reference power command to the system every control cycle, directly issuing the reference power command could result in significant differences between adjacent outputs when the operating condition or upper-level control suddenly switches. This would lead to "power spikes," threatening bus safety. This application, by limiting the power command change rate (Ramp limit), can suppress these "spiking" effects.

[0016] 4. The technical solution of this application makes full use of photovoltaic energy, reduces the overall operating cost of microgrid by reducing the curtailment rate, and achieves the continuous conversion of renewable energy through high hydrogen storage utilization. Attached Figure Description

[0017] The accompanying drawings, which are provided to further illustrate this application and form part of this application, illustrate exemplary embodiments of this application and are used to explain this application, but do not constitute an undue limitation of this application.

[0018] Figure 1 A flowchart of a photovoltaic-storage-hydrogen smart microgrid management method provided for this application. Detailed Implementation

[0019] Example: This application uses a typical AC-coupled microgrid consisting of a 380V / 50 Hz AC bus (external power grid), a 108 kW PV photovoltaic system, a 320 kW / 600 kWh lithium-ion battery (BESS), a 50 kW proton exchange membrane electrolyzer (PEM), and a 10 kW fuel cell (FC), with an external load of 150 kW. In the description of the embodiments, abbreviations are used to describe the systems, such as PV, BESS, PEM, and FC.

[0020] Hardware Integration: The computing unit's hardware system utilizes a domestically produced x86-64 8-core, 16-thread CPU at 3.0GHz and 16GB of DDR4-ECC memory. For communication, the CPU motherboard integrates a gigabit switching chip, providing 5 RJ45 ports. Ports 1, 2, 3, and 4 form an EtherCAT ring network connecting one AC / DC converter, one AC / DC bidirectional converter, and two DC / AC inverters. Port 5 interfaces with the Energy Management System (EMS) via OPCUA. Power supply and storage are standard computer configurations.

[0021] The software stack deployment is achieved through existing technologies. At the data exchange level, the calculation and recognition results are written to the real-time PLC via shared memory with a cycle of 100ms. The PLC process data is mapped to the converter and inverter via EtherCAT to regulate the system power.

[0022] Based on the foregoing, as attached Figure 1 As shown, this application implements a photovoltaic-storage-hydrogen smart microgrid management method. This method is based on an AC-coupled microgrid composed of photovoltaic (PV), lithium-ion battery (BESS), proton exchange membrane electrolyzer, fuel cell (FC), and mains power grid, and includes the following steps: S1. Identify the operating conditions of the AC-coupled microgrid based on real-time electricity price, real-time energy storage capacity, and hydrogen storage capacity, and execute system actions according to the operating conditions.

[0023] Step S1 corresponds to the upper scheduling layer. In step S1, the AC-coupled microgrid includes eight operating conditions, and the identification criteria for these operating conditions are as follows: Operating condition 1: and ; Operating condition 2: and ; Operating condition 3: and ; Operating condition 4: ≤0.2 and ; Operating condition 5: and ; Operating condition 6: and ; Operating condition 7: or ; Operating condition 8: and ; In the above formula: Indicates real-time photovoltaic power; Indicates the real-time power of the load; Indicates the real-time capacity of energy storage; Indicates the real-time hydrogen storage capacity; Indicates the maximum load capacity; Indicates real-time electricity price; This indicates a high electricity price; Indicates the threshold for real-time photovoltaic power change; Indicates the threshold for real-time load power change; Indicates the real-time voltage value; MAX represents the maximum voltage capacity; This indicates the maximum hydrogen storage capacity.

[0024] Each operating condition corresponds to a code value. It executes corresponding actions based on the operating conditions. Power output configuration is based on the actions performed.

[0025] The actions to be performed in operating condition 1 are as follows: and The power difference is prioritized to drive the proton exchange membrane electrolyzer for hydrogen production. If there is still a power difference, it is used to charge the lithium-ion battery (BESS). Operating condition 1 occurs during daytime when there is excess PV power and the battery is not fully charged. In this case, the wasted solar power is minimized and long-term hydrogen storage is prioritized.

[0026] The actions to be performed in operating condition 2 are as follows: and The power surplus is prioritized to drive the proton exchange membrane (PEM) electrolyzer for hydrogen production. If there is still a power surplus, it is sold to the external power grid. Operating condition 2 occurs during the daytime when there is a surplus of PV power and the batteries are fully charged, thereby avoiding the curtailment of solar power and selling electricity.

[0027] The action performed in operating condition 3 is: independent discharge of the lithium battery BESS to compensate. and The power difference; Operating condition 3 occurs when there is insufficient PV during the day and batteries can be discharged. BESS provides large-capacity and rapid buffering, and stabilizes voltage and frequency.

[0028] The action performed under operating condition 4 is: start the fuel cell FC to supplement the AC-coupled microgrid. and If the power difference cannot be made up, electricity will be purchased from the external grid. Operating condition 4 occurs when there is insufficient PV during the day, the battery capacity is low but the hydrogen storage capacity is high. In this case, the action is to release hydrogen as a backup to protect the life of the BESS.

[0029] Operating mode 5 involves the following actions: stopping the proton exchange membrane (PEM) electrolyzer and supplying power to the AC-coupled microgrid in the order of lithium battery (BESS) and external power grid. Operating mode 5 is used for low-load conditions at night, reducing dependence on the power grid by prioritizing BESS discharge.

[0030] Operating mode 6 executes the following actions: power is supplied in the order of lithium battery BESS, fuel cell FC, and external power grid. Operating mode 6 is used for peak load pricing at night to avoid purchasing electricity at high prices.

[0031] Operating condition 7 operates by supplying power in the following order: lithium battery BESS, fuel cell FC, and then the external power grid. Operating condition 7 is suitable for situations with sudden weather / load changes, with the BESS acting as the primary buffer.

[0032] Operating conditions 6 and 7 perform the same actions, but in practice, the BESS in operating condition 7 allows for the establishment of a step current to achieve rapid power supply, while operating condition 6 does not allow for a step current. In practice, the IGBT bridge arm current loop bandwidth of the BESS bidirectional PCS is ≥2 kHz, allowing a 0→320 kW step current to be established within <100 ms.

[0033] The actions performed under operating condition 8 are: shutting down the proton exchange membrane electrolyzer and forcing the photovoltaic (PV) to charge the lithium battery BESS; or shutting down the proton exchange membrane electrolyzer and allowing the photovoltaic (PV) to sell electricity to the external power grid.

[0034] Operating condition 8 requires determining whether the BESS is at full capacity for both actions. If the BESS capacity exceeds 80%, electricity is sold to the external grid; otherwise, the BESS is charged. Operating condition 8 provides protection against full power consumption to prevent overvoltage / hydrogen waste.

[0035] Of the eight operating conditions mentioned above, operating conditions 1 through 4 are switched during the day, operating conditions 5 and 6 are switched at night, and operating conditions 7 and 8 can be switched throughout the day. The daytime period is defined as 7:00 to 18:00, and the remaining time is defined as nighttime.

[0036] S2. Output the power of each system in the AC-coupled microgrid under the identified operating conditions according to the optimal electricity price model and the power balance model, and use the output power of each system under the operating condition corresponding to the lowest electricity price as the configuration power.

[0037] Step S2 corresponds to the intermediate power allocation layer, and the optimal electricity price model in step S2 is as follows: ; The power balance model in step S2 is as follows: ; In the above formula, This indicates the lowest possible electricity price. Indicates the unit price of electricity; Indicates the power at the grid connection point; Indicates the charging / discharging power of the energy storage battery; This represents the equivalent cost of battery discharge. This represents the equivalent cost of hydrogen storage discharge. This indicates the hydrogen production / discharge power of the hydrogen storage system.

[0038] In the optimal electricity price model , This is the equivalent cost of the system, which includes system depreciation and the opportunity cost of hydrogen storage.

[0039] The calculation methods for the equivalent cost of electrochemical energy storage and hydrogen energy storage can refer to IEC 62933, NREL, and IEA's open guidelines for hydrogen LCOH. Initial installation cost of battery system, lithium iron phosphate: ¥1.2~1.6 / Wh; L bat Calendar lifespan: 10-15 years; OPEX bat Annual maintenance, 1%~2% of the initial installation fee; Q life Total throughput over lifecycle: Enom × DoD × N_cycle; Enom: Rated capacity; DoD: Loop depth, 0.8-0.9; N_cycle: Number of cycles, 6000~8000 for lithium iron phosphate.

[0040] ; Annuity stack Annualized cost of electrolytic cells; Annuity tank Annualized cost of hydrogen storage tanks; Annuity FC Annualized cost of fuel cells; OPEX H2 Total annual maintenance and upkeep of the hydrogen system; Mlife: Total hydrogen production throughout its entire lifecycle.

[0041] The electricity price optimization model and power balance model in step S2 must satisfy the following constraints: ; ; ; ; ; ; ; In the above formula, Indicates the rated capacity of the photovoltaic system; and These represent the minimum and maximum power of the energy storage battery during charging / discharging, respectively. , , These represent the maximum / minimum hydrogen production capacity allowed for hydrogen storage; Indicates the maximum available power purchase capacity of the external power grid; , These represent the minimum remaining capacity ratio and the maximum remaining capacity ratio of the battery, respectively. , These represent the maximum and minimum allowable charging / discharging power of the battery, respectively. Indicates battery charge / discharge efficiency; Indicates the optimization time step; "Don't" indicates the minimum hydrogen storage capacity.

[0042] The above constraints cover multiple levels of constraints, including equipment capacity, energy flow coupling, upper and lower limits of energy storage safety, and main grid / microgrid switching strategies.

[0043] S3. Adjust the current and / or voltage of the converter to enable each system in the AC-coupled microgrid to reach the configured power calculated in step S2; Step S3 corresponds to the execution layer. For step S3, when the operating condition changes: A price-triggered criterion with a hysteresis interval is introduced as a condition switching criterion; When performing a change of operating conditions: A first-order inertial smoothing element and a ramp-limited power input optimization are introduced.

[0044] The method for introducing a price trigger criterion with a hysteresis interval as a condition switching criterion is as follows: SA1, Define the lower threshold for electricity price p LOW and upper threshold p UP : p LOW = ; p UP = ; In the formula, This indicates the threshold for determining electricity purchase eligibility. Indicates the hysteresis range of electricity prices; SA2, Define the initial state valley price condition S(k) = 0; SA3, Update State Judgment Function According to the judgment function The output result will trigger a switching action; ; In the formula, S(k−1) represents the previous state. This indicates the electricity price corresponding to the current state. The update of the state judgment function S(k) is a recursive function that depends on the previous state S(k−1) and the electricity price p(k) corresponding to the current state.

[0045] By setting a hysteresis interval, "jitter" and frequent actions of operating conditions and instructions during power purchase switching are avoided. Specifically, the operating condition switch is only triggered when the real-time electricity price p(t) crosses the entire interval from the outside. State judgment relies on historical judgment results S(k−1), which ensures the "memory" effect of the hysteresis. For example, if the current price is at a valley level (S=0), p(t) must rise to p... up Only after reaching the peak price can one switch to the trough price; conversely, switching back from the peak price to the trough price requires a drop to p. low The following constraints are still required to respond to daytime and nighttime operating conditions: If S(k)=0, switching can only be performed between operating conditions 1, 2, 3, 4, 5, and 8; If S(k)=1, the switching can only be performed in operating conditions 6 and 7.

[0046] First-order inertial smoothing element based on sampling period accomplish: y[k]=y[k−1]+Δt / (t+Δt)(u[k]−y[k−1]); In the formula, u represents the original reference command, y represents the smoothed output power command, t represents the response speed parameter, and k represents the current cycle.

[0047] The ramp rate is based on the reference power command issued by the management system. accomplish: when hour, ; when hour, ; when hour, ; In the above formula, Indicates the reference power change value. ; Indicates the Ramp limit rate; This indicates a power control command issued by the control system; This indicates the power control command issued by the control system at the previous moment.

[0048] For any parts not mentioned in this application, existing technologies may be used or referenced.

[0049] The above description is merely an embodiment of this application and is not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. A photovoltaic-storage-hydrogen intelligent microgrid management method, wherein the method is based on an AC-coupled microgrid composed of photovoltaic (PV), lithium-ion battery (BESS), proton exchange membrane electrolyzer, fuel cell (FC), and mains power grid, characterized in that, Includes the following steps: S1. Identify the operating conditions of the AC-coupled microgrid based on real-time electricity price, real-time energy storage capacity, and hydrogen storage capacity, and execute system actions according to the operating conditions; S2. Output the power of each system in the AC-coupled microgrid under the identified operating conditions according to the optimal electricity price model and the power balance model, and use the output power of each system under the operating conditions corresponding to the lowest electricity price as the configuration power. S3. Adjust the current and / or voltage of the converter to enable each system in the AC-coupled microgrid to reach the configured power calculated in step S2; For step S3, when the operating condition changes: A price-triggered criterion with a hysteresis interval is introduced as a condition switching criterion; When performing a working condition switch: A first-order inertial smoothing element and a ramp-limited power input optimization are introduced.

2. The photovoltaic-storage-hydrogen smart microgrid management method according to claim 1, characterized in that, In step S1, the AC-coupled microgrid includes eight operating conditions, and the identification criteria for these operating conditions are as follows: Operating condition 1: and ; Operating condition 2: and ; Operating condition 3: and ; Operating condition 4: ≤0.2 and ; Operating condition 5: and ; Operating condition 6: and ; Operating condition 7: or ; Operating condition 8: and ; In the above formula: Indicates real-time photovoltaic power; Indicates the real-time power of the load; Indicates the real-time capacity of electrochemical energy storage; Indicates the real-time hydrogen storage capacity; Indicates the maximum load capacity; Indicates real-time electricity price; This indicates a high electricity price. Indicates the threshold for real-time photovoltaic power change; Indicates the threshold for real-time load power change; Indicates the real-time voltage value; MAX represents the maximum voltage capacity; This indicates the maximum hydrogen storage capacity.

3. The photovoltaic-storage-hydrogen smart microgrid management method according to claim 2, characterized in that, The actions to be performed in operating condition 1 are as follows: and The power difference is used to drive the proton exchange membrane (PEM) electrolyzer to produce hydrogen first, and if there is still a power difference, it is used to charge the lithium battery (BESS). The actions to be performed in operating condition 2 are as follows: and The power difference is used to drive the proton exchange membrane (PEM) electrolyzer to produce hydrogen first, and if there is still a power difference, it is sold to the external power grid. The action performed in operating condition 3 is: independent discharge of the lithium battery BESS to compensate. and The power difference; The action performed under operating condition 4 is: start fuel cell FC replenishment. and If the power difference cannot be made up, electricity will be purchased from the external power grid; The actions performed under operating condition 5 are as follows: stop the proton exchange membrane electrolyzer and supply power in the order of lithium battery BESS and external power grid. The operation in operating condition 6 is as follows: power is supplied in the order of lithium battery BESS, fuel cell FC, and external power grid. The execution action of operating condition 7 is as follows: power is supplied in the order of lithium battery BESS, fuel cell FC, and external power grid; among which, this execution action allows BESS to establish a step current; The actions performed under operating condition 8 are: shutting down the proton exchange membrane electrolyzer and forcing the photovoltaic (PV) to charge the lithium battery BESS; Alternatively, the proton exchange membrane (PEM) electrolyzer can be shut down, and the photovoltaic (PV) system can sell electricity to the external power grid.

4. The photovoltaic-storage-hydrogen smart microgrid management method according to claim 3, characterized in that, The optimal electricity price model in step S2 is as follows: ； The power balance model in step S2 is as follows: ； In the above formula, This indicates the lowest possible electricity price. Indicates the unit price of electricity; Indicates the power at the grid connection point; Indicates the charging / discharging power of the energy storage battery; This represents the equivalent cost of battery discharge. This represents the equivalent cost of hydrogen storage discharge. This indicates the hydrogen production / discharge power of the hydrogen storage system.

5. The photovoltaic-storage-hydrogen smart microgrid management method according to claim 4, characterized in that, The electricity price optimization model and power balance model in step S2 must satisfy the following constraints: ； ； ； ； ； ； ； In the above formula, Indicates the rated capacity of the photovoltaic system; and These represent the minimum and maximum power of the energy storage battery during charging / discharging, respectively. , These represent the maximum / minimum hydrogen production capacity allowed for hydrogen storage; Indicates the maximum available power purchase capacity of the external power grid; , These represent the minimum remaining capacity ratio and the maximum remaining capacity ratio of the battery, respectively. , These represent the maximum and minimum allowable charging / discharging power of the battery, respectively. Indicates battery charge / discharge efficiency; Indicates the optimization time step; "Don't" indicates the minimum hydrogen storage capacity.

6. The photovoltaic-storage-hydrogen smart microgrid management method according to claim 5, characterized in that, The method for introducing a price trigger criterion with a hysteresis interval as a condition switching criterion is as follows: SA1, Define the lower threshold for electricity price p LOW and upper threshold p UP : p LOW = ； p UP = ； In the formula, This indicates the threshold for determining electricity purchase eligibility. Indicates the hysteresis range of electricity prices; SA2, Define the initial state valley price condition S(k) = 0; SA3, Update State Judgment Function According to the judgment function The output result will trigger a switching action; ； In the formula, S(k−1) represents the previous state. This indicates the electricity price corresponding to the current state.

7. The photovoltaic-storage-hydrogen smart microgrid management method according to claim 6, characterized in that, First-order inertial smoothing element based on sampling period accomplish: y[k]=y[k−1]+Δt / (t+Δt)(u[k]−y[k−1]); In the formula, u represents the original reference command, y represents the smoothed output power command, t represents the response speed parameter, and k represents the current cycle.

8. The photovoltaic-storage-hydrogen smart microgrid management method according to claim 6, characterized in that, Ramp limit is based on reference power commands issued by the management system. accomplish: when hour, ; when hour, ; when hour, ; In the above formula, Indicates the reference power change value. ; Indicates the Ramp limit rate; This indicates a power control command issued by the control system; This indicates the power control command issued by the control system at the previous moment.

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