Mesh-forming type electric hydrogen ammonia fusion micro-grid system and control method, equipment and medium thereof

Abstract

The invention provides a network construction type electric hydrogen ammonia fusion micro-grid system, a control method and equipment thereof and a medium, and belongs to the technical field of micro-grids. In the system, a network-forming type lithium battery energy storage subsystem discharges electricity to a high-voltage alternating-current bus, an ammonia fuel power generation subsystem generates electricity to a low-voltage alternating-current bus through an AC / AC converter, an alternating-current load takes electricity to the low-voltage alternating-current bus, and a photovoltaic power generation subsystem and a fuel cell power generation subsystem generate electricity to a direct-current bus through an energy router. The hydrogen production subsystem and the direct-current load take electricity from the direct-current bus through the energy router, the super-capacitor energy storage subsystem and the electrochemical energy storage subsystem take electricity from the direct-current bus or discharge electricity from the direct-current bus through the energy router, and the super-capacitor energy storage subsystem discharges electricity from the network-forming type lithium battery energy storage subsystem through an independent contactor. The DC bus is connected with the low-voltage AC bus through the energy router, and the high-voltage AC bus is connected with the low-voltage AC bus through the transformer. The operation reliability of the system can be improved.

Description

Technical Field

[0001] This application relates to the field of microgrid technology, and in particular to a grid-type electro-hydrogen-ammonia integrated microgrid system and its control methods, equipment and media. Background Technology

[0002] Existing microgrid systems often lack black-start capability when external grid faults or power outages occur, making it impossible to quickly restore power supply and affecting the reliability and continuity of microgrid system operation. In addition, microgrid systems typically rely on the voltage and frequency support of the external grid. When the microgrid system is in islanded mode, traditional grid-connected energy storage devices struggle to actively establish a stable bus voltage environment, resulting in insufficient system transient stability. Summary of the Invention

[0003] The main purpose of this application is to propose a grid-type integrated electric-hydrogen-ammonia microgrid system and its control methods, equipment and media, aiming to improve the system's operational reliability and transient stability.

[0004] To achieve the above objectives, one aspect of this application proposes a grid-type integrated electric-hydrogen-ammonia microgrid system, comprising a DC bus, a low-voltage AC bus, a high-voltage AC bus, a grid-type lithium battery energy storage subsystem, an ammonia fuel cell power generation system, an AC load, an AC / AC converter, a transformer, an independent contactor, an energy router, and a photovoltaic power generation system, a hydrogen production subsystem, a supercapacitor energy storage subsystem, an electrochemical energy storage subsystem, a fuel cell power generation system, and a DC load connected to the DC bus via the energy router. The DC bus is connected to the low-voltage AC bus via the energy router, and the high-voltage AC bus is connected to the low-voltage AC bus via the transformer. The grid-type lithium battery energy storage subsystem is connected to the high-voltage AC bus for discharge; the ammonia fuel cell power generation system is connected to the low-voltage AC bus via the AC / AC converter for power generation, and the AC load is connected to the low-voltage AC bus for power supply; the photovoltaic power generation system and the fuel cell power generation system both generate electricity from the DC bus, the hydrogen production subsystem draws power from the DC bus for hydrogen production, the supercapacitor energy storage subsystem and the electrochemical energy storage subsystem both draw power from the DC bus for charging or discharging, the supercapacitor energy storage subsystem is connected to the grid-type lithium battery energy storage subsystem via the independent contactor for discharge, and the DC load draws power from the DC bus for operation.

[0005] Furthermore, the grid-type lithium battery energy storage subsystem includes a lithium-ion battery compartment, an integrated energy storage converter and booster compartment, and an energy storage synchronizing device connected in sequence, wherein the energy storage synchronizing device is connected to the high-voltage AC bus. The lithium-ion battery compartment is used to supply DC power to the integrated energy storage converter and booster compartment. The integrated energy storage converter and booster compartment is used to convert and boost the received DC power to AC power before supplying it to the energy storage synchronizing device. The energy storage synchronizing device is used to frequency and phase modulate the received AC power before supplying it to the high-voltage AC bus.

[0006] To achieve the above objectives, another aspect of this application proposes a control method applied to the aforementioned grid-type electro-hydrogen-ammonia integrated microgrid system, the control method comprising: Obtain the voltage amplitude of the low-voltage AC bus at the current moment and record it as the first voltage amplitude; When the first voltage amplitude is zero, a preset black-start strategy is used to control the grid-type electro-hydrogen-ammonia integrated microgrid system; When the grid-type integrated electric-hydrogen-ammonia microgrid system is connected to the grid during the black start recovery phase, the voltage amplitude of the low-voltage AC bus at the current moment is obtained in real time and recorded as the second voltage amplitude. When the second voltage amplitude is less than the first preset voltage threshold or the voltage fluctuation rate determined based on the second voltage amplitude is greater than the preset voltage fluctuation rate threshold, a preset voltage ride-through strategy is adopted to control the grid-type electric-hydrogen-ammonia integrated microgrid system.

[0007] Furthermore, the control method further includes: When the first voltage amplitude is greater than zero but less than the second preset voltage threshold, a preset voltage ride-through strategy is used to control the grid-type electro-hydrogen-ammonia integrated microgrid system. When the grid-type electric-hydrogen-ammonia integrated microgrid system is in the voltage ride-through stage, the voltage amplitude of the low-voltage AC bus at the current moment is obtained in real time and recorded as the third voltage amplitude. At the same time, all voltage change rates generated during the process of changing from the first voltage amplitude to the third voltage amplitude are obtained. When the third voltage amplitude is equal to zero and the voltage change trend determined based on all voltage change rates is a downward trend, a preset black start strategy is adopted to control the grid-type electric-hydrogen-ammonia integrated microgrid system.

[0008] Furthermore, the control of the grid-type electro-hydrogen-ammonia integrated microgrid system using a preset black-start strategy includes: The independent contactor is controlled to be in the closed state, and then the supercapacitor energy storage subsystem is controlled to discharge through the independent contactor, so that the grid-type lithium battery energy storage subsystem is started and discharged, so as to gradually establish the voltage of the high voltage AC bus, the no-load voltage of the low voltage AC bus and the no-load voltage of the DC bus. The system controls the energy router to restore power supply to the DC load, then controls the ammonia fuel power generation system to generate electricity, thereby restoring power supply to the AC load, and finally controls the fuel cell power generation system to generate electricity.

[0009] Furthermore, the control of the grid-type electro-hydrogen-ammonia integrated microgrid system using a preset voltage ride-through strategy includes: First, the supercapacitor energy storage subsystem is controlled to discharge through the energy router, then the electrochemical energy storage subsystem is controlled to discharge, and finally the ammonia fuel power generation system is controlled to generate electricity.

[0010] Furthermore, the control method further includes: When the grid-type integrated electric-hydrogen-ammonia microgrid system is not in the black-start recovery phase or voltage ride-through phase, the power status information of the energy router is obtained; When the power status information indicates that the energy router is in a state of excess power, the hydrogen production subsystem is controlled first to produce hydrogen, then the supercapacitor energy storage subsystem is controlled to charge, then the electrochemical energy storage subsystem is controlled to charge, and finally the energy router is controlled to convert the excess electrical energy on the DC bus into AC electrical energy and transmit it to the low-voltage AC bus.

[0011] Furthermore, the control method further includes: When the power status information indicates that the energy router is in a power deficit state, the supercapacitor energy storage subsystem is controlled to discharge first, followed by the electrochemical energy storage subsystem, then the fuel cell power generation system and / or ammonia fuel power generation system are controlled to generate electricity, and finally the energy router is controlled to convert the electrical energy on the low-voltage AC bus into DC power and transmit it to the DC bus.

[0012] To achieve the above objectives, another aspect of this application proposes an electronic device, which includes a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the control method described above.

[0013] To achieve the above objectives, another aspect of this application proposes a computer-readable storage medium storing a computer program that, when executed by a processor, implements the control method described above.

[0014] This application includes at least the following beneficial effects: By constructing a grid-connected lithium battery energy storage subsystem within the microgrid system, a black-start function can be provided to quickly restore power supply in the event of external grid failures or power outages. It can also proactively establish a stable bus voltage environment when the microgrid system is in islanded mode. Furthermore, by constructing a dual-core collaborative architecture of "grid-connected lithium battery energy storage - hydrogen-ammonia energy chain" within the microgrid system for multi-energy complementarity and energy conversion, it is beneficial to achieve efficient utilization of renewable energy, long-term storage, and flexible dispatch. By analyzing the voltage amplitude of the low-voltage AC bus under different operating conditions and rationally employing preset black-start and voltage ride-through strategies to control the microgrid system, the reliability and stability of the microgrid system operation can be ensured. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the composition of a grid-type electro-hydrogen-ammonia integrated microgrid system provided in an embodiment of this application; Figure 2 This is a schematic flowchart of a control method for a grid-type electro-hydrogen-ammonia integrated microgrid system provided in an embodiment of this application; Figure 3 This is a schematic diagram of the hardware structure of the electronic device provided in the embodiments of this application. Detailed Implementation

[0016] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of this application and are not intended to limit it. In the following description, when referring to the accompanying drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with those of this application; they are merely examples of systems and methods consistent with some aspects of the embodiments of this application as detailed in the appended claims.

[0017] It is understood that the terms “first,” “second,” etc., used in this application may be used herein to describe various concepts, but unless otherwise stated, these concepts are not limited by these terms. These terms are only used to distinguish one concept from another. For example, without departing from the scope of the embodiments of this application, first information may also be referred to as second information, and similarly, second information may also be referred to as first information. Depending on the context, the words “if,” “when,” or “in response to a determination” as used herein may be interpreted as “when…” or “when…” or “in response to a determination.”

[0018] As used in this application, the terms "at least one", "multiple", "each", "any", etc., "at least one" includes one, two or more, "multiple" includes two or more, "each" refers to each of the corresponding multiples, and "any" refers to any one of the multiples.

[0019] Unless otherwise defined, 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 application belongs. The terminology used herein is for the purpose of describing embodiments of this application only and is not intended to limit this application.

[0020] Please see Figure 1 , Figure 1 This is an optional schematic diagram of a grid-type integrated electric-hydrogen-ammonia microgrid system provided in an embodiment of this application. The grid-type integrated electric-hydrogen-ammonia microgrid system includes a DC bus, a high-voltage AC bus, a low-voltage AC bus, a grid-type lithium battery energy storage subsystem, an ammonia fuel cell power generation system, AC loads, an AC / AC converter, a transformer, an independent contactor, an energy router, and a photovoltaic power generation system, a hydrogen production subsystem, a supercapacitor energy storage subsystem, an electrochemical energy storage subsystem, a fuel cell power generation system, and DC loads connected to the DC bus via the energy router. The DC bus is connected to the low-voltage AC bus via the energy router, the high-voltage AC bus is connected to the low-voltage AC bus via the transformer, the grid-type lithium battery energy storage subsystem is connected to the high-voltage AC bus, the ammonia fuel cell power generation system is connected to the low-voltage AC bus via the AC / AC converter, and the AC loads are connected to the low-voltage AC bus. The DC bus is preferably a 750V DC bus, the low-voltage AC bus is preferably a 380V AC bus, the high-voltage AC bus is preferably a 10kV AC bus, and the transformer is a 10 / 0.4kV transformer.

[0021] Specifically, the energy router is a multi-port energy router, internally equipped with at least a first unidirectional DC / DC converter, a second unidirectional DC / DC converter, a third unidirectional DC / DC converter, a fourth unidirectional DC / DC converter, a first bidirectional DC / DC converter, a second bidirectional DC / DC converter, and a bidirectional AC / DC converter. The photovoltaic power generation system is connected to the DC bus via the first unidirectional DC / DC converter, and the hydrogen production subsystem is connected to the DC bus via the second unidirectional DC / DC converter. The hydrogen production subsystem is preferably a PEM (Power Module). The electrolyzer hydrogen production subsystem includes a supercapacitor energy storage subsystem connected to the DC bus via a first bidirectional DC / DC converter, an electrochemical energy storage subsystem connected to the DC bus via a second bidirectional DC / DC converter (preferably a conventional lithium-ion energy storage subsystem), a fuel cell power generation subsystem connected to the DC bus via a third unidirectional DC / DC converter, a DC load connected to the DC bus via a fourth unidirectional DC / DC converter, and the DC bus connected to the low-voltage AC bus via a bidirectional AC / DC converter.

[0022] In practical applications, the grid-type lithium battery energy storage subsystem discharges to the high-voltage AC bus, the ammonia fuel cell power generation system generates electricity to the low-voltage AC bus, the AC load draws power from the low-voltage AC bus for operation, the photovoltaic power generation system and the fuel cell power generation system both generate electricity to the DC bus, the hydrogen production subsystem draws power from the DC bus for hydrogen production, the supercapacitor energy storage subsystem and the electrochemical energy storage subsystem both draw power from the DC bus for charging or discharging to the DC bus, the supercapacitor energy storage subsystem is connected to the grid-type lithium battery energy storage subsystem through the independent contactor for discharging, and the DC load draws power from the DC bus for operation.

[0023] In some embodiments, the grid-type lithium battery energy storage subsystem is essentially a voltage source. It can employ droop control, virtual synchronizing machines, or power synchronization control strategies to directly regulate the active / reactive power of the power grid, actively participate in grid frequency and voltage regulation, and support off-grid black start to build its own voltage when there is no grid support. The grid-type lithium battery energy storage subsystem includes a lithium-ion battery compartment, an integrated energy storage converter and booster compartment, and an energy storage synchronizing device. The lithium-ion battery compartment is connected to the integrated energy storage converter and booster compartment, which is connected to the energy storage synchronizing device, which is connected to the high-voltage AC bus.

[0024] In practical applications, the lithium-ion battery compartment is used to supply DC power to the integrated energy storage converter and booster compartment. The integrated energy storage converter and booster compartment is used to convert and boost the received DC power to AC power before supplying it to the energy storage synchronizing device. The energy storage synchronizing device is used to frequency and phase modulate the received AC power before supplying it to the high-voltage AC bus.

[0025] In some embodiments, the interior of the lithium-ion battery compartment is provided with at least a lithium-ion battery pack, a combiner cabinet, a battery management system, and a liquid cooling system. The lithium-ion battery pack is connected to the combiner cabinet, the combiner cabinet is connected to the integrated energy storage converter booster compartment, the combiner cabinet is connected to the battery management system, and the battery management system is connected to the liquid cooling system. The lithium-ion battery pack includes multiple battery modules, each battery module includes several cells, each battery module is equipped with a corresponding temperature sensor, and the temperature sensor is connected to the battery management system.

[0026] In practical applications, the current output from the lithium-ion battery pack is collected by the combiner cabinet and transmitted to the integrated energy storage converter booster compartment for processing. This current information is then transmitted to the battery management system (BMS), which monitors the overall discharge status of the lithium-ion battery compartment based on this information to prevent over-discharge and ensure the safe operation of the lithium-ion battery pack. The BMS also receives real-time battery temperature information from all temperature sensors and transmits it to the liquid cooling system. The liquid cooling system adjusts its heat dissipation control strategy based on this information, such as increasing the coolant circulation rate when the temperature of a particular battery module rises, to ensure that the battery module's temperature remains within a suitable range, thus avoiding impacts on its performance and lifespan. Furthermore, the BMS performs equalization control on each cell within each battery module during charging and discharging, ensuring that the voltage of each cell is consistent. It also monitors and analyzes parameters such as the total voltage, total current, remaining capacity, and health status of the battery module to more accurately assess its overall performance and remaining usable capacity.

[0027] In some embodiments, the integrated energy storage converter and booster compartment is equipped with at least a grid-type lithium-ion energy storage converter, an auxiliary transformer, a dual-winding transformer, and a distribution cabinet. The DC terminal of the grid-type lithium-ion energy storage converter is connected to the combiner cabinet inside the lithium-ion battery compartment. The AC terminal of the grid-type lithium-ion energy storage converter is connected in parallel with the primary side of the auxiliary transformer and then connected to the secondary side of the dual-winding transformer. The primary side of the dual-winding transformer is connected to the distribution cabinet, which is connected to the energy storage synchronizing device. The integrated energy storage converter and booster compartment is also equipped with low-voltage equipment (such as lighting equipment, fire-fighting equipment, etc.), and the secondary side of the auxiliary transformer is connected to the power supply terminal of the low-voltage equipment.

[0028] The preferred grid-type lithium-ion energy storage converter is a 1250kW grid-type lithium-ion energy storage converter, and the preferred number of such converters is two. This 1250kW grid-type lithium-ion energy storage converter can be constructed using a voltage source converter topology based on IGBT (Insulated Gate Bipolar Transistor). It mainly uses AC-side filters to filter switching frequency harmonics, AC and DC-side EMC (Electromagnetic Compatibility) filters to filter high-frequency harmonic interference, load switches and fuses on the DC side to protect and isolate DC-side faults, and contactors and circuit breakers on the AC side to connect to the AC-side grid and isolate faults.

[0029] In practical applications, the DC power supplied by the combiner cabinet is converted into AC power by the grid-type lithium-ion energy storage converter and transmitted to the auxiliary transformer. The auxiliary transformer then steps down the converted AC power appropriately. Part of the stepped-down AC power can power the low-voltage equipment, while the other part can be transmitted to the dual-winding transformer. The stepped-down AC power is generally 220V single-phase AC power or 380V three-phase AC power. The dual-winding transformer then steps up the stepped-down AC power and transmits it to the distribution cabinet. Finally, the distribution cabinet distributes the stepped-up AC power to the energy storage synchronizing device for grid connection, ensuring a smooth transition of the grid-type lithium battery energy storage subsystem during grid-connection or off-grid switching and avoiding inrush current and voltage fluctuations.

[0030] In some embodiments, the energy storage synchronizing device is internally equipped with a grid-connected switch. Based on real-time monitoring of the voltage amplitude, frequency, phase, and other electrical parameters of the high-voltage AC bus, the energy storage synchronizing device adjusts the AC power supplied to the distribution cabinet inside the energy storage converter-boost integrated cabin until the relevant electrical parameters meet the synchronization conditions. Then, it controls the grid-connected switch to be closed to connect the adjusted AC power to the high-voltage AC bus, thereby minimizing the impact on the high-voltage AC bus during grid connection. Preferably, the synchronization conditions are set as follows: the frequency difference between the two components falls within the range of 0.25Hz to 0.5Hz, the voltage amplitude difference falls within the range of 5% to 10%, and the phases are the same. It should be noted that when the high-voltage AC bus experiences a power outage and needs to be rebuilt, the energy storage synchronizing device, when adjusting the AC power supplied to the distribution cabinet inside the energy storage converter-boost integrated cabin, generally refers to preset electrical parameters such as the preset voltage amplitude, preset frequency, and preset phase of the high-voltage AC bus set in advance by technicians.

[0031] In some embodiments, the ammonia fuel power generation system includes an ammonia storage tank, an ammonia cracking unit, and a gas turbine connected in sequence. Ammonia is supplied to the ammonia cracking unit through the ammonia storage tank, and then the ammonia is decomposed by the ammonia cracking unit. The decomposed hydrogen is then transported to the gas turbine for combustion to generate high-temperature gas to drive the turbine to generate electricity.

[0032] In some embodiments, the grid-type integrated electric-hydrogen-ammonia microgrid system further includes a hydrogen storage tank connected to the hydrogen production subsystem for hydrogen storage and connected to the fuel cell power generation system for hydrogen supply.

[0033] The grid-connected electric-hydrogen-ammonia integrated microgrid system provided in this application embodiment, by constructing a grid-connected lithium battery energy storage subsystem within the microgrid system, can provide a black-start function to quickly restore power supply in the event of external grid failures or power outages. It can also proactively establish a stable bus voltage environment when the microgrid system is in islanded mode. By constructing a dual-core collaborative architecture of "grid-connected lithium battery energy storage - hydrogen-ammonia energy chain" within the microgrid system for multi-energy complementarity and energy conversion, it is beneficial to achieve efficient utilization of renewable energy, long-term storage, and flexible dispatch.

[0034] Please see Figure 2 , Figure 2 This is an optional flowchart illustrating a control method for a grid-type electro-hydrogen-ammonia integrated microgrid system provided in this application embodiment. The control method may include, but is not limited to, the following steps S101 to S107: Step S101: Obtain the voltage amplitude of the low-voltage AC bus at the current moment and record it as the first voltage amplitude; Step S102: When the amplitude of the first voltage is zero, a preset black start strategy is used to control the grid-type electric-hydrogen-ammonia integrated microgrid system. Step S103: When the grid-connected electric-hydrogen-ammonia integrated microgrid system is connected to the grid during the black start recovery phase, the voltage amplitude of the low-voltage AC bus at the current moment is obtained in real time and recorded as the second voltage amplitude. Step S104: When the second voltage amplitude is less than the first preset voltage threshold or the voltage fluctuation rate determined based on the second voltage amplitude is greater than the preset voltage fluctuation rate threshold, it indicates that the grid voltage is in a fluctuating state. At this time, the preset voltage ride-through strategy is used to control the grid-type electric-hydrogen-ammonia integrated microgrid system. Step S105: When the first voltage amplitude is greater than zero but less than the second preset voltage threshold, the preset voltage ride-through strategy is used to control the grid-type electric-hydrogen-ammonia integrated microgrid system. Step S106: When the grid-type electric-hydrogen-ammonia integrated microgrid system is in the voltage ride-through stage, the voltage amplitude of the low-voltage AC bus at the current moment is obtained in real time and recorded as the third voltage amplitude. At the same time, all voltage change rates generated during the process of changing from the first voltage amplitude to the third voltage amplitude are obtained. Step S107: When the third voltage amplitude is equal to zero and the voltage change trend determined based on all voltage change rates is a downward trend, it indicates that the grid voltage has not recovered to the normal range and has further deteriorated. At this time, the preset black start strategy is used to control the grid-type electric-hydrogen-ammonia integrated microgrid system.

[0035] It should be noted that in step S104 above, when the second voltage amplitude is greater than or equal to the first preset voltage threshold and the voltage fluctuation rate is less than or equal to the preset voltage fluctuation rate threshold, it indicates that the grid voltage is in a stable state. At this time, the grid-type electric-hydrogen-ammonia integrated microgrid system is controlled to maintain normal grid connection.

[0036] Wherein, the first preset voltage threshold is greater than the second preset voltage threshold. The first preset voltage threshold is preferably set to 0.9pu, and the second preset voltage threshold is preferably set to 0.2pu, where pu refers to per-unit value. The voltage fluctuation rate is generally obtained by subtracting the second voltage amplitude from the preset reference voltage amplitude, and then dividing the result by the preset reference voltage amplitude. The preset reference voltage amplitude can be understood as the grid connection point voltage amplitude of the microgrid system during normal operation.

[0037] It should be noted that in step S107 above, when the third voltage amplitude is greater than or equal to the first preset voltage threshold, it indicates that the grid voltage has returned to the normal range. At this time, the preset voltage ride-through strategy is stopped from controlling the grid-type electric-hydrogen-ammonia integrated microgrid system, and the preset black-start strategy is also unnecessary to control the grid-type electric-hydrogen-ammonia integrated microgrid system.

[0038] For example, in step S106 above, the step of obtaining all voltage change rates generated during the process of changing from the first voltage amplitude to the third voltage amplitude can be understood as follows: if the first voltage amplitude is obtained at time T and the third voltage amplitude is obtained at time T+N, then the first voltage change rate is calculated based on the voltage amplitude of the low-voltage AC bus obtained at time T+1 and the first voltage amplitude. Then, the second voltage change rate is calculated based on the voltage amplitude of the low-voltage AC bus obtained at time T+2 and the voltage amplitude of the low-voltage AC bus obtained at time T+1, and so on, until the Nth voltage change rate is calculated based on the third voltage amplitude and the voltage amplitude of the low-voltage AC bus obtained at time T+N-1.

[0039] In step S107 above, the voltage change trend can be obtained, but is not limited to, by the following methods: count the number of all voltage change rates obtained and record it as the first number; then select all voltage change rates less than zero from all the obtained voltage change rates; count the number of all selected voltage change rates and record it as the second number; then calculate the proportion of the second number to the first number; use this proportion to reflect the voltage change trend; when the proportion exceeds a preset proportion threshold, the voltage change trend is determined to be a downward trend; wherein, the preset proportion threshold is preferably set to 70% or even higher.

[0040] In steps S102 and S107 of some embodiments, the preset black-start strategy is mainly used to control the microgrid system to recover from a complete shutdown state to a normal operating state. This preset black-start strategy generally follows the principles of tiered start-up and multi-source coordination to achieve phased power restoration. Regarding the step of controlling the grid-type electric-hydrogen-ammonia integrated microgrid system using this preset black-start strategy, the corresponding implementation methods may include, but are not limited to, the following: The independent contactor is controlled to be in the closed state, and then the supercapacitor energy storage subsystem is controlled to discharge through the independent contactor, so that the grid-type lithium battery energy storage subsystem is started and discharged, so as to gradually establish the voltage of the high voltage AC bus, the no-load voltage of the low voltage AC bus and the no-load voltage of the DC bus. The millisecond-level response capability of the supercapacitor is beneficial to quickly activate the high voltage system in extreme temperature environments. Then, the power router is controlled to restore power supply to the DC load, but power supply to the AC load is not restored temporarily to avoid overload impact, and the photovoltaic power generation system, hydrogen production subsystem, fuel cell power generation system and electrochemical energy storage subsystem are kept in standby mode. Finally, the ammonia fuel power generation system is controlled to generate electricity, thereby restoring the power supply to the AC load. Subsequently, the fuel cell power generation system is controlled to generate electricity as a backup power source.

[0041] It should be noted that after establishing the no-load voltage of the low-voltage AC bus, the independent contactor is usually kept in the open state to avoid excessive energy consumption of the supercapacitor energy storage subsystem.

[0042] Preferably, the control power supply of the energy router can be set to be powered by the supercapacitor energy storage subsystem or a dedicated backup battery, ensuring that the first bidirectional DC / DC converter inside the energy router can be activated in complete darkness, thereby enabling the supercapacitor energy storage subsystem to simultaneously discharge to the DC bus through the first bidirectional DC / DC converter to help establish the no-load voltage of the DC bus.

[0043] In steps S104 and S105 of some embodiments, the preset voltage ride-through strategy is mainly used to deal with fault situations such as grid voltage fluctuations (e.g., short-term voltage drops). This preset voltage ride-through strategy generally follows a multi-level response principle to achieve continuous grid-connected operation. Regarding the step of controlling the grid-connected electric-hydrogen-ammonia integrated microgrid system using this preset voltage ride-through strategy, the corresponding implementation methods may include, but are not limited to, the following: First, the supercapacitor energy storage subsystem is controlled to discharge through the energy router. Within 2ms of detecting a voltage drop, the supercapacitor's millisecond-level response characteristic is used to quickly provide power support, which can suppress voltage drops caused by instantaneous faults such as lightning strikes and short circuits. Then, the electrochemical energy storage subsystem is controlled to discharge. After the supercapacitor supports the system, it seamlessly switches to the lithium battery to provide continuous power in constant voltage mode, avoiding a secondary voltage drop after the supercapacitor is decommissioned due to capacity limitations. This can also cope with continuous voltage disturbances caused by photovoltaic fluctuations. Subsequently, the ammonia fuel cell power generation system is controlled to generate electricity. It is generally activated at the end of the lithium battery support period and reaches its rated power in a short time to directly supply power to the AC load.

[0044] In some embodiments, the control method applied to the above-described grid-type electro-hydrogen-ammonia integrated microgrid system may further include the following steps S201 to S203: Step S201: When the grid-type electric-hydrogen-ammonia integrated microgrid system is not in the black start recovery phase or voltage ride-through phase, obtain the power status information of the energy router; Step S202: When the power status information indicates that the energy router is in a state of power surplus, the hydrogen production subsystem is controlled first to produce hydrogen, then the supercapacitor energy storage subsystem is controlled to charge, then the electrochemical energy storage subsystem is controlled to charge, and finally the energy router is controlled to convert the excess power on the DC bus into AC power and transmit it to the low-voltage AC bus. Step S203: When the power status information indicates that the energy router is in a power deficit state, the supercapacitor energy storage subsystem is controlled to discharge first, the electrochemical energy storage subsystem is controlled to discharge second, the fuel cell power generation system and / or ammonia fuel power generation system are controlled to generate electricity, and finally the energy router is controlled to convert the electrical energy on the low-voltage AC bus into DC electrical energy and transmit it to the DC bus.

[0045] In step S201 above, the power generation capacity and DC load demand power within the grid-type electric-hydrogen-ammonia integrated microgrid system can be obtained, and the power status information can be determined based on the relationship between the photovoltaic power generation capacity and the DC load demand power. Specifically, when the photovoltaic power generation capacity is greater than the DC load demand power, the power status information indicates that the grid-type electric-hydrogen-ammonia integrated microgrid system is in a power surplus state; when the photovoltaic power generation capacity is less than the DC load demand power, the power status information indicates that the grid-type electric-hydrogen-ammonia integrated microgrid system is in a power deficit state.

[0046] In step S202 above, it should be understood that if the hydrogen storage tank reaches a predetermined capacity before controlling the hydrogen production subsystem to produce hydrogen, then controlling the hydrogen production subsystem to produce hydrogen is stopped, and the supercapacitor energy storage subsystem is selected to be charged instead; if the state of charge of the supercapacitor inside the supercapacitor energy storage subsystem reaches the charging limit before controlling the supercapacitor energy storage subsystem to be charged, then controlling the supercapacitor energy storage subsystem to be charged is stopped, and the electrochemical energy storage subsystem is selected to be charged instead; if the state of charge of the lithium battery inside the electrochemical energy storage subsystem reaches the charging limit before controlling the electrochemical energy storage subsystem to be charged, then controlling the electrochemical energy storage subsystem to be charged is stopped, and the energy router is selected to convert the excess electrical energy on the DC bus into AC electrical energy and transmit it to the low-voltage AC bus.

[0047] The statement regarding selecting and controlling the energy router to convert excess electrical energy on the DC bus into AC electrical energy can be further understood as: selecting and controlling the bidirectional AC / DC converter in the energy router to convert excess electrical energy on the DC bus into AC electrical energy.

[0048] In step S203 above, it should be understood that if the state of charge of the supercapacitor inside the supercapacitor is detected to be lower than the first preset safety threshold before the supercapacitor energy storage subsystem is controlled to discharge, the discharge of the supercapacitor energy storage subsystem is stopped, and the electrochemical energy storage subsystem is selected to discharge instead; if the state of charge of the lithium battery inside the electrochemical energy storage subsystem is detected to be lower than the second preset safety threshold before the discharge of the electrochemical energy storage subsystem, the discharge of the electrochemical energy storage subsystem is stopped, and the fuel cell power generation system and / or the ammonia fuel power generation system is selected to generate electricity instead; if the capacity of the hydrogen storage tank and the capacity of the ammonia storage tank inside the ammonia fuel power generation system are detected to be insufficient before the power generation of the fuel cell power generation system and / or the ammonia fuel power generation system, the power generation of the fuel cell power generation system and / or the ammonia fuel power generation system is stopped, and the energy router is selected to convert the electrical energy on the low-voltage AC bus into DC electrical energy and transmit it to the DC bus.

[0049] The statement regarding the selection and control of the energy router to convert the electrical energy on the low-voltage AC bus into DC power can be further understood as: the bidirectional AC / DC converter in the energy router will convert the electrical energy on the low-voltage AC bus into DC power.

[0050] The control method provided in this application for the above-mentioned grid-type electro-hydrogen-ammonia integrated microgrid system analyzes the voltage amplitude of the low-voltage AC bus under different operating periods to reasonably adopt preset black-start strategy and preset voltage ride-through strategy to control the microgrid system. This ensures the reliability and stability of the microgrid system and enhances its fault response capability. In addition, by controlling the operation of relevant internal components based on the power state information of the microgrid system, the energy utilization efficiency of the microgrid system can be optimized, and dynamic power balance of the microgrid system can be achieved.

[0051] This application also provides an electronic device, which includes a memory and a processor. The memory stores a computer program, and the processor executes the computer program to implement the control method described above for a grid-type electro-hydrogen-ammonia integrated microgrid system. This electronic device can include any smart terminal such as a smartphone, tablet, laptop, or desktop computer.

[0052] It is understood that the content of the above method embodiments is applicable to the present device embodiments. The specific functions implemented by the present device embodiments are the same as those implemented by the above method embodiments, and the beneficial effects achieved by the present device embodiments are also the same as those achieved by the above method embodiments.

[0053] Please see Figure 3 , Figure 3 This illustrates the hardware structure of an electronic device according to another embodiment, the electronic device comprising: The processor 301 can be implemented using a general-purpose CPU (Central Processing Unit), microprocessor, application-specific integrated circuit (ASIC), or one or more integrated circuits, and is used to execute relevant programs to implement the technical solutions provided in the embodiments of this application. The memory 302 can be implemented as a read-only memory (ROM), a static storage device, a dynamic storage device, or a random access memory (RAM). The memory 302 can store the operating system and other applications. When the technical solutions provided in the embodiments of this application are implemented through software or firmware, the relevant program code is stored in the memory 302 and is called and executed by the processor 301. Input / output interface 303 is used to implement information input and output; The communication interface 304 is used to enable communication and interaction between this device and other devices. Communication can be achieved through wired means (such as USB, network cable, etc.) or wireless means (such as mobile network, WIFI, Bluetooth, etc.). Bus 305 transmits information between various components of the device (e.g., processor 301, memory 302, input / output interface 303, and communication interface 304); The processor 301, memory 302, input / output interface 303 and communication interface 304 are connected to each other within the device via bus 305.

[0054] This application also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-described control method applied to a grid-type electro-hydrogen-ammonia integrated microgrid system.

[0055] It is understood that the content of the above method embodiments is applicable to this storage medium embodiment. The specific functions implemented by this storage medium embodiment are the same as those implemented by the above method embodiments, and the beneficial effects achieved by this storage medium embodiment are also the same as those achieved by the above method embodiments.

[0056] Memory, as a non-transitory computer-readable storage medium, can be used to store non-transitory software programs and non-transitory computer-executable programs. Furthermore, memory may include high-speed random access memory, and may also include non-transitory memory, such as at least one disk storage device, flash memory device, or other non-transitory solid-state storage device. In some embodiments, memory may optionally include memory remotely located relative to the processor, and these remote memories can be connected to the processor via a network. Examples of such networks include, but are not limited to, the Internet, intranets, local area networks, mobile communication networks, and combinations thereof.

[0057] The embodiments described in this application are for the purpose of more clearly illustrating the technical solutions of the embodiments of this application, and do not constitute a limitation on the technical solutions provided by the embodiments of this application. As those skilled in the art will know, with the evolution of technology and the emergence of new application scenarios, the technical solutions provided by the embodiments of this application are also applicable to similar technical problems.

[0058] Those skilled in the art will understand that the technical solutions shown in the figures do not constitute a limitation on the embodiments of this application, and may include more or fewer steps than shown, or combine certain steps, or different steps.

[0059] The system embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs.

[0060] Those skilled in the art will understand that all or some of the steps in the methods disclosed above, as well as the functional modules / units in the systems and devices, can be implemented as software, firmware, hardware, or suitable combinations thereof.

[0061] The terms “first,” “second,” “third,” “fourth,” etc. (if present) in the specification and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms “comprising” and “having,” and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises 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.

[0062] It should be understood that in this application, "at least one (item)" means one or more, and "more than" means two or more. "And / or" is used to describe the relationship between related objects, indicating that three relationships can exist. For example, "A and / or B" can represent three cases: only A exists, only B exists, and both A and B exist simultaneously, where A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. "At least one (item) of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one (item) of a, b, or c can represent: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, and c can be single or multiple.

[0063] In the embodiments provided in this application, it should be understood that the disclosed systems and methods can be implemented in other ways. For example, the system embodiments described above are merely illustrative; for instance, the division of the units described above is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between systems or units may be electrical, mechanical, or other forms.

[0064] The units described above as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0065] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0066] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes multiple instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of this application. The aforementioned storage medium includes various media capable of storing programs, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0067] The preferred embodiments of the present application have been described above with reference to the accompanying drawings, but this does not limit the scope of the claims of the present application. Any modifications, equivalent substitutions, and improvements made by those skilled in the art without departing from the scope and substance of the embodiments of the present application shall be within the scope of the claims of the present application.

Claims

1. A grid-type integrated electric-hydrogen-ammonia microgrid system, characterized in that, It includes a DC bus, a high-voltage AC bus, a low-voltage AC bus, a grid-type lithium battery energy storage subsystem, an ammonia fuel cell power generation system, AC loads, an AC / AC converter, a transformer, an independent contactor, an energy router, and a photovoltaic power generation system, a hydrogen production subsystem, a supercapacitor energy storage subsystem, an electrochemical energy storage subsystem, a fuel cell power generation system, and DC loads connected to the DC bus via the energy router. The DC bus is connected to the low-voltage AC bus via the energy router, and the high-voltage AC bus is connected to the low-voltage AC bus via the transformer. The grid-type lithium battery energy storage subsystem is connected to the high-voltage AC bus for discharge; the ammonia fuel cell power generation system is connected to the low-voltage AC bus via the AC / AC converter for power generation, and the AC load is connected to the low-voltage AC bus for power supply; the photovoltaic power generation system and the fuel cell power generation system both generate electricity from the DC bus, the hydrogen production subsystem draws power from the DC bus for hydrogen production, the supercapacitor energy storage subsystem and the electrochemical energy storage subsystem both draw power from the DC bus for charging or discharging, the supercapacitor energy storage subsystem is connected to the grid-type lithium battery energy storage subsystem via the independent contactor for discharge, and the DC load draws power from the DC bus for operation.

2. The grid-type electro-hydrogen-ammonia integrated microgrid system according to claim 1, characterized in that, The grid-type lithium battery energy storage subsystem includes a lithium-ion battery compartment, an integrated energy storage converter and booster compartment, and an energy storage synchronizing device connected in sequence. The energy storage synchronizing device is connected to the high-voltage AC bus. The lithium-ion battery compartment is used to supply DC power to the integrated energy storage converter and booster compartment. The integrated energy storage converter and booster compartment is used to convert and boost the received DC power to AC power before supplying it to the energy storage synchronizing device. The energy storage synchronizing device is used to frequency and phase modulate the received AC power before supplying it to the high-voltage AC bus.

3. A control method applied to the grid-type electro-hydrogen-ammonia integrated microgrid system as described in claim 1 or 2, characterized in that, The control method includes: Obtain the voltage amplitude of the low-voltage AC bus at the current moment and record it as the first voltage amplitude; When the first voltage amplitude is zero, a preset black-start strategy is used to control the grid-type electro-hydrogen-ammonia integrated microgrid system; When the grid-type integrated electric-hydrogen-ammonia microgrid system is connected to the grid during the black start recovery phase, the voltage amplitude of the low-voltage AC bus at the current moment is obtained in real time and recorded as the second voltage amplitude. When the second voltage amplitude is less than the first preset voltage threshold or the voltage fluctuation rate determined based on the second voltage amplitude is greater than the preset voltage fluctuation rate threshold, a preset voltage ride-through strategy is adopted to control the grid-type electric-hydrogen-ammonia integrated microgrid system.

4. The control method according to claim 3, characterized in that, The control method further includes: When the first voltage amplitude is greater than zero but less than the second preset voltage threshold, a preset voltage ride-through strategy is used to control the grid-type electro-hydrogen-ammonia integrated microgrid system. When the grid-type electric-hydrogen-ammonia integrated microgrid system is in the voltage ride-through stage, the voltage amplitude of the low-voltage AC bus at the current moment is obtained in real time and recorded as the third voltage amplitude. At the same time, all voltage change rates generated during the process of changing from the first voltage amplitude to the third voltage amplitude are obtained. When the third voltage amplitude is equal to zero and the voltage change trend determined based on all voltage change rates is a downward trend, a preset black start strategy is adopted to control the grid-type electric-hydrogen-ammonia integrated microgrid system.

5. The control method according to claim 3 or 4, characterized in that, The control of the grid-type electro-hydrogen-ammonia integrated microgrid system using a preset black-start strategy includes: The independent contactor is controlled to be in the closed state, and then the supercapacitor energy storage subsystem is controlled to discharge through the independent contactor, so that the grid-type lithium battery energy storage subsystem is started and discharged, so as to gradually establish the voltage of the high voltage AC bus, the no-load voltage of the low voltage AC bus and the no-load voltage of the DC bus. The system controls the energy router to restore power supply to the DC load, then controls the ammonia fuel power generation system to generate electricity, thereby restoring power supply to the AC load, and finally controls the fuel cell power generation system to generate electricity.

6. The control method according to claim 3 or 4, characterized in that, The control of the grid-type electro-hydrogen-ammonia integrated microgrid system using a preset voltage ride-through strategy includes: First, the supercapacitor energy storage subsystem is controlled to discharge through the energy router, then the electrochemical energy storage subsystem is controlled to discharge, and finally the ammonia fuel power generation system is controlled to generate electricity.

7. The control method according to claim 4, characterized in that, The control method further includes: When the grid-type integrated electric-hydrogen-ammonia microgrid system is not in the black-start recovery phase or voltage ride-through phase, the power status information of the energy router is obtained; When the power status information indicates that the energy router is in a state of excess power, the hydrogen production subsystem is controlled first to produce hydrogen, then the supercapacitor energy storage subsystem is controlled to charge, then the electrochemical energy storage subsystem is controlled to charge, and finally the energy router is controlled to convert the excess electrical energy on the DC bus into AC electrical energy and transmit it to the low-voltage AC bus.

8. The control method according to claim 7, characterized in that, The control method further includes: When the power status information indicates that the energy router is in a power deficit state, the supercapacitor energy storage subsystem is controlled to discharge first, followed by the electrochemical energy storage subsystem, then the fuel cell power generation system and / or ammonia fuel power generation system are controlled to generate electricity, and finally the energy router is controlled to convert the electrical energy on the low-voltage AC bus into DC power and transmit it to the DC bus.

9. An electronic device, characterized in that, The electronic device includes a memory and a processor, the memory storing a computer program, and the processor executing the computer program to implement the control method according to any one of claims 3 to 8.

10. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements the control method according to any one of claims 3 to 8.

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