Offshore wind-solar hydrogen storage ammonia-alcohol-based constructed network control system and broadband oscillation prevention and control method

Abstract

The invention relates to the technical field of electric energy storage systems, in particular to an offshore wind-solar hydrogen storage ammonia-alcohol-based constructed network control system and a broadband oscillation prevention and control method. Comprising an offshore hydrogen-ammonia-alcohol base, an offshore wind power base, an offshore photovoltaic base, an inverter station, an offshore wind-light base energy storage power station, a booster station, a network-forming type energy storage phase modulation power station and a broadband oscillation control and prevention device, so that the network-forming type energy storage control research of the offshore wind-light hydrogen-ammonia-alcohol multi-energy complementary base can be carried out under low-short-circuit-ratio access and isolated network operation. Voltage, frequency and short-circuit capacity adjustment and inertia supporting are achieved, oscillation prevention and control can be carried out, and the purposes of power grid supporting optimization adjustment and oscillation treatment are achieved; meanwhile, multi-energy complementation is achieved, the energy utilization rate is increased, hydrogen ammonia alcohol can be prepared through green energy, and carbon emission is reduced. Therefore, the problems of poor frequency stability, weak voltage supporting capability, serious weak power grid oscillation and the like in the prior art are solved.

Description

Technical Field

[0001] This application relates to the technical field of power energy storage systems, and particularly to a grid-forming control system for an offshore wind-solar-hydrogen-ammonia-alcohol base and a method for preventing and controlling broadband oscillations. Background Art

[0002] With the grid connection of a high proportion of renewable energy, the inertia of synchronous machines in the traditional power grid decreases, resulting in a reduction in system strength (short circuit ratio), which causes the following problems: 1. Frequency stability: Wind and solar power sources lack inertial response, and frequency fluctuations intensify; 2. Voltage support ability: Power electronic devices (such as grid-following inverters) rely on the grid voltage and cannot build voltage independently; 3. Weak grid oscillations: Under low short-circuit capacity, the interaction of control loops causes subsynchronous oscillations or high-frequency resonances.

[0003] In summary, the prior art has poor frequency stability, weak voltage support ability, and serious weak grid oscillations, which urgently need to be solved. Summary of the Invention

[0004] This application provides a grid-forming control system for an offshore wind-solar-hydrogen-ammonia-alcohol base and a method for preventing and controlling broadband oscillations to solve the problems of poor frequency stability, weak voltage support ability, and serious weak grid oscillations in the prior art.

[0005] An anti - broadband oscillation prevention method for a grid - forming control system of an offshore wind - solar - hydrogen - ammonia - alcohol base provided by an embodiment of the first aspect of the present application includes the following steps: an offshore wind power base, the input end of the offshore wind power base is connected to the first output end of a preset offshore hydrogen - ammonia - alcohol base, which is used to provide offshore wind power resources, and in the case of islanded operation and high wind power generation, connect to a preset hydrogen electrolyzer to produce hydrogen; an offshore photovoltaic base, the input end of the offshore photovoltaic base is connected to the second output end of the offshore hydrogen - ammonia - alcohol base, which is used to provide offshore photovoltaic power resources, and in the case of islanded operation and high photovoltaic power generation, connect to the hydrogen electrolyzer to produce hydrogen; an offshore hydrogen - ammonia - alcohol base, which is used to utilize the excess electric energy and hydrogen of the offshore wind power base and the offshore photovoltaic base to produce hydrogen - ammonia - alcohol, so as to perform multi - energy complementary power generation with the offshore wind power base and the offshore photovoltaic base, and at the same time provide raw material supply for target ships and distributed power generation units; an inverter station, the input end of the inverter station is connected to the output end of the offshore photovoltaic base, which is used to convert the direct current output by the offshore photovoltaic base into alternating current; an offshore wind - solar base energy storage power station, the first input end of the offshore wind - solar base energy storage power station is connected to the output end of the offshore wind power base, the second input end of the offshore wind - solar base energy storage power station is connected to the output end of the inverter station, and the output end of the offshore wind - solar base energy storage power station is connected to a preset first busbar, which is used to smooth the alternating current output of the offshore wind power base and the offshore photovoltaic base, and output or store corresponding active power and reactive power according to the output power of the offshore wind power base and the offshore photovoltaic base to balance the power of the target power system; a booster station, the input end of the booster station is connected to the first busbar, and the output end of the booster station is connected to a preset second busbar, which is used to increase the alternating current output by the offshore wind - solar base energy storage power station to the target voltage level; a grid - forming energy storage phase - regulating power station, the input end of the grid - forming energy storage phase - regulating power station is connected to the second busbar, and the output end of the grid - forming energy storage phase - regulating power station is connected to a preset third busbar, which is used to perform preset grid - forming and phase - regulating operations on the alternating current of the target voltage level to generate the target alternating current after grid - forming, and perform corresponding broadband impedance scanning operations on the target alternating current to obtain the full - network impedance, and based on the full - network impedance, judge whether the target alternating current has an oscillation risk; a broadband oscillation control and prevention device, the input end of the broadband oscillation control and prevention device is connected to the third busbar, which is used to perform preset broadband oscillation prevention operations in the case that the target alternating current has the oscillation risk. Among them, the grid - forming static compensator bank and the grid - forming unified power flow controller bank in the broadband oscillation control and prevention device have impedance regulation functions and grid - forming attributes.

[0006] According to the above technical means, in the embodiments of the present application, through an offshore photovoltaic base, an inverter station, an offshore hydrogen-ammonia-alcohol base, a network-forming energy storage phase-modulating power station, an offshore wind-solar base energy storage power station, a booster station, etc., research on the network-forming control and broadband oscillation prevention method of the offshore wind-solar-hydrogen-ammonia-alcohol multi-energy complementary base can be carried out under low short-circuit ratio access and islanded operation. Thereby, multi-energy complementarity can be achieved, the energy utilization rate is improved, and hydrogen-ammonia-alcohol can be prepared from green energy, reducing carbon emissions.

[0007] Optionally, in an embodiment of the present application, the network-forming energy storage phase-modulating power station includes: Multiple multi-energy storage units; Multiple synchronous phase modifiers; A synchronous phase modifier group formed by connecting the multiple synchronous phase modifiers in series; Multiple network-forming energy storage converters, the input ends of the multiple network-forming energy storage converters are connected to the output ends of the multiple multi-energy storage units, and are used to provide target alternating current with a preset frequency and having network-forming attributes by using a preset network-forming control strategy; Multiple energy storage modules composed of the multiple multi-energy storage units and the multiple network-forming energy storage converters; An energy storage module group formed by connecting the multiple energy storage modules in series; Multiple network-forming energy storage phase-modulating controllers, the output ends of each phase of the network-forming energy storage phase-modulating controllers are connected to the input ends of the synchronous phase modifier group, and the input ends of each phase of the network-forming energy storage phase-modulating controllers are connected to the energy storage module group, and are used to coordinately control the energy storage module group and the synchronous phase modifier group to perform primary, secondary, and tertiary frequency modulation and voltage regulation, as well as regulation operations of active power, reactive power, and short-circuit capacity.

[0008] According to the above technical means, in the embodiments of the present application, an N energy storage module group is constructed by N energy storage modules composed of N multi-energy storage units and N network-forming energy storage converters, an energy storage module group formed by connecting N energy storage module groups in series, a synchronous phase modifier group formed by connecting N synchronous phase modifiers in series, and each phase of network-forming energy storage phase-modulating controllers, thereby realizing voltage, frequency, short-circuit capacity adjustment, and inertia support; at the same time, research on the network-forming energy storage control of the offshore wind-solar-hydrogen-ammonia-alcohol multi-energy complementary base can be carried out under the condition of low short-circuit ratio access, providing reliable technical guidance and basis for the optimization regulation and oscillation governance of the power grid.

[0009] Optionally, in an embodiment of the present application, the multi-energy storage unit includes: a supercapacitor bank for providing inertia support for instantaneous energy storage; a sodium-ion battery bank for performing energy storage operations meeting the requirements of a first preset duration; a hydrogen storage device for performing energy storage operations meeting the requirements of a second preset duration.

[0010] According to the above technical means, in the embodiment of the present application, a multi - energy storage unit is formed by using a sodium - ion battery pack, a supercapacitor pack, and a hydrogen storage device, thereby providing hardware support for electric energy storage and ensuring the reliability of the subsequent construction of a grid - forming energy storage phase - regulating power station.

[0011] Optionally, in an embodiment of the present application, when accessing at a low short - circuit ratio, a synchronous phase modifier in the grid - forming energy storage phase - regulating power station is used to provide short - circuit capacity.

[0012] According to the above technical means, in the embodiment of the present application, under the condition of accessing at a low short - circuit ratio, a synchronous phase modifier can provide short - circuit capacity, thereby improving system stability.

[0013] Optionally, in an embodiment of the present application, the offshore wind power base includes: multiple grid - forming wind turbines; a wind turbine control device, which is connected in parallel with the multiple grid - forming wind turbines and is used to obtain the wind speed information corresponding to the offshore wind power base during normal operation, determine the type of grid - forming wind turbine to be operated according to the wind speed information, and distribute the active power and reactive power generated among the multiple wind turbines in the offshore wind power base through the wind turbine control device, where the types of grid - forming wind turbines include doubly - fed wind turbines and direct - drive wind turbines.

[0014] According to the above technical means, in the embodiment of the present application, an offshore wind power base is constructed by multiple grid - forming wind turbines and a wind turbine control device, thereby providing important technical support for the generation of offshore wind power energy.

[0015] Optionally, in an embodiment of the present application, the offshore photovoltaic base includes: photovoltaic panels, which are used to obtain the solar energy resources of the offshore photovoltaic base and convert the solar energy resources into offshore photovoltaic power resources.

[0016] According to the above technical means, in the embodiment of the present application, an offshore photovoltaic base is constructed by photovoltaic panels, thereby ensuring the realization of offshore wind - solar energy complementarity.

[0017] Optionally, in an embodiment of the present application, the offshore wind - solar base energy storage power station includes: a lithium iron phosphate and lithium titanate battery cabin composed of a preset lithium iron phosphate battery system, a lithium titanate battery system, a battery control cabinet, a battery power supply cabinet, a battery management system, an energy management system, and a grid - following inverter, which is used to smooth the output of the offshore wind power base and the offshore photovoltaic base and balance the active power and reactive power of the system, where the lithium iron phosphate battery system and the lithium titanate battery system include multiple groups of lithium iron phosphate and lithium titanate battery packs connected in parallel, and the lithium iron phosphate and lithium titanate battery packs are composed of lithium iron phosphate batteries and lithium titanate batteries connected in series.

[0018] According to the above technical means, in the embodiment of the present application, an energy storage power station for an offshore wind and solar base is formed by a lithium iron phosphate battery compartment and a lithium titanate battery compartment to smooth the output of the wind and solar base, thereby balancing the active power and reactive power of the system.

[0019] Optionally, in an embodiment of the present application, the broadband oscillation control and prevention device includes: a virtual impedance control system, configured to determine whether increasing or decreasing the impedance will continue to cause oscillation when the target alternating current has the oscillation risk, wherein when increasing or decreasing the impedance will not continue to cause oscillation, adjusting the parameters of a preset PID controller to adjust the impedance; the network-forming unified power flow controller group and the network-forming static compensator group, configured to adjust the parameters of the PID controller to adjust the impedance until no oscillation occurs when increasing or decreasing the impedance will continue to cause oscillation.

[0020] According to the above technical means, in the embodiment of the present application, a broadband oscillation control and prevention device is constructed by a virtual impedance control system, a network-forming unified power flow controller group and a network-forming static compensator group, and oscillation prevention can be carried out.

[0021] Optionally, in an embodiment of the present application, the network-forming static compensator group and the network-forming unified power flow controller group have network-forming attributes. By adjusting the reactive power in the network-forming static compensator group, the voltage amplitude is adjusted, and by adjusting the network-forming unified power flow controller group, the voltage amplitude and phase angle are adjusted.

[0022] According to the above technical means, in the embodiment of the present application, by using the network-forming static compensator group and the network-forming unified power flow controller group with impedance adjustment functions and network-forming attributes, the adjustment of the voltage amplitude and voltage phase angle is realized, achieving the purpose of optimized adjustment of grid support and oscillation control.

[0023] The second aspect of the present application provides a grid-forming control system for an offshore wind-solar-hydrogen-ammonia-alcohol base, including the following steps: providing offshore wind power resources and offshore photovoltaic power resources through a preset offshore wind power base and an offshore photovoltaic base, and connecting a preset hydrogen electrolyzer under islanded operation and high wind power generation conditions to produce hydrogen; based on a preset offshore hydrogen-ammonia-alcohol base, using the surplus electric energy and the hydrogen of the offshore wind power base and the offshore photovoltaic base to produce hydrogen-ammonia-alcohol, so as to provide raw material supply for target ships and distributed power generation units while performing multi-energy complementary power generation with the offshore wind power base and the offshore photovoltaic base; converting the direct current output by the offshore photovoltaic base into alternating current, smoothing the output of the alternating current generated by the offshore wind power base and the offshore photovoltaic base, and outputting or storing corresponding active power and reactive power according to the output power of the offshore wind power base and the offshore photovoltaic base to balance the power of the target power system; raising the alternating current output by the offshore wind-solar base energy storage power station to a target voltage level, performing preset grid-forming and phase adjustment operations on the alternating current of the target voltage level through a grid-forming energy storage phase adjustment power station to generate the target alternating current after grid-forming, and performing a broadband impedance scanning operation of 0.1~2500HZ on the target alternating current to obtain the full network impedance, and based on the full network impedance, judging whether there is an oscillation risk in the target alternating current, and performing a preset broadband oscillation prevention and control operation in the case that the target alternating current has the oscillation risk.

[0024] Therefore, the embodiments of the present application have the following beneficial effects: The embodiments of the present application include an offshore hydrogen-ammonia-alcohol base, an offshore wind power base, an offshore photovoltaic base, an inverter station, an offshore wind-solar base energy storage power station, a booster station, a grid-forming energy storage phase adjustment power station, and a broadband oscillation control and prevention device, so that grid-forming energy storage control research on an offshore wind-solar-hydrogen-ammonia-alcohol multi-energy complementary base can be carried out under low short-circuit ratio access and islanded operation, realizing voltage, frequency, short-circuit capacity adjustment and inertia support, and oscillation prevention and control can be carried out to achieve the purpose of optimized regulation of grid support and oscillation control; at the same time, multi-energy complementarity is realized, the energy utilization rate is improved, and hydrogen-ammonia-alcohol can be prepared by green energy, reducing carbon emissions. Through the offshore photovoltaic base, the inverter station, the offshore hydrogen-ammonia-alcohol base, the grid-forming energy storage phase adjustment power station, the offshore wind-solar base energy storage power station booster station, etc., the present application can carry out research on grid-forming control and broadband oscillation prevention and control methods for an offshore wind-solar-hydrogen-ammonia-alcohol multi-energy complementary base under low short-circuit ratio access and islanded operation, so as to be able to realize multi-energy complementarity, improve the energy utilization rate, and prepare hydrogen-ammonia-alcohol by green energy, reducing carbon emissions. Thus, the problems of poor frequency stability, weak voltage support ability, and serious oscillation of weak power grids in the prior art are solved.

[0025] Additional aspects and advantages of the present application will be given in part in the following description, become apparent in part from the following description, or be learned through the practice of the present application. Description of the Drawings

[0026] The above and / or additional aspects and advantages of the present application will become apparent and be readily understood from the following description of embodiments in conjunction with the drawings, where: Figure 1 FIG. is an example diagram of a grid-forming control system for an offshore wind-solar-hydrogen-ammonia-alcohol base according to an embodiment of the present application; Figure 2 FIG. is a schematic diagram of voltage control of a grid-forming energy storage phase modulation controller provided for an embodiment of the present application; Figure 3 FIG. is a schematic structural diagram of a grid-forming energy storage phase modulation power station provided for an embodiment of the present application; Figure 4 FIG. is an internal circuit connection diagram of a grid-forming energy storage phase modulation power station provided for an embodiment of the present application; Figure 5 FIG. is a flowchart of a method for preventing and controlling broadband oscillation of a grid-forming control system for an offshore wind-solar-hydrogen-ammonia-alcohol base according to an embodiment of the present application.

[0027] Wherein, 10 - grid-forming control system for offshore wind-solar-hydrogen-ammonia-alcohol base; 100 - offshore hydrogen-ammonia-alcohol base, 200 - offshore wind power base, 300 - offshore photovoltaic base, 400 - inverter station, 500 - energy storage power station for offshore wind-solar base, 600 - booster station, 700 - grid-forming energy storage phase modulation power station, 800 - broadband oscillation control and prevention device. Detailed Embodiments

[0028] Embodiments of the present application will be described in detail below. Examples of the embodiments are shown in the drawings, where the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the drawings are exemplary and are intended to explain the present application and should not be construed as limiting the present application.

[0029] The grid-forming control system and broadband oscillation prevention method for an offshore wind-solar-hydrogen-ammonia-alcohol base according to an embodiment of the present application will be described below with reference to the accompanying drawings. In view of the problems mentioned in the above background art, the present application provides a grid-forming control system for an offshore wind-solar-hydrogen-ammonia-alcohol base. In this system, it includes an offshore hydrogen-ammonia-alcohol base, an offshore wind power base, an offshore photovoltaic base, an inverter station, an offshore wind-solar base energy storage power station, a booster station, a grid-forming energy storage phase modulation power station, and a broadband oscillation control and prevention device. Thus, research on grid-forming energy storage control for an offshore wind-solar-hydrogen-ammonia multi-energy complementary base can be carried out under low short-circuit ratio connection and islanded operation, achieving voltage, frequency, short-circuit capacity adjustment, and inertia support, and oscillation prevention can be carried out to achieve the optimized regulation of grid support and oscillation control; at the same time, multi-energy complementarity is realized, the energy utilization rate is improved, and hydrogen-ammonia-alcohol can be prepared from green energy, reducing carbon emissions. Through the offshore photovoltaic base, inverter station, offshore hydrogen-ammonia-alcohol base, grid-forming energy storage phase modulation power station, offshore wind-solar base energy storage power station, booster station, etc., the present application can carry out research on grid-forming control and broadband oscillation prevention methods for an offshore wind-solar-hydrogen-ammonia multi-energy complementary base under low short-circuit ratio connection and islanded operation. Thus, multi-energy complementarity can be realized, the energy utilization rate is improved, and hydrogen-ammonia-alcohol can be prepared from green energy, reducing carbon emissions. Thereby, the problems of poor frequency stability, weak voltage support ability, and severe oscillation in weak power grids in the prior art are solved.

[0030] First, the grid-forming control system for an offshore wind-solar-hydrogen-ammonia-alcohol base according to an embodiment of the present application will be described with reference to the accompanying drawings.

[0031] Specifically, Figure 1 is a block diagram of the grid-forming control system for an offshore wind-solar-hydrogen-ammonia-alcohol base according to an embodiment of the present application.

[0032] As Figure 1 shown, the grid-forming control system 10 for an offshore wind-solar-hydrogen-ammonia-alcohol base includes: an offshore hydrogen-ammonia-alcohol base 100, an offshore wind power base 200, an offshore photovoltaic base 300, an inverter station 400, an offshore wind-solar base energy storage power station 500, a booster station 600, a grid-forming energy storage phase modulation power station 700, and a broadband oscillation control and prevention device 800.

[0033] Among them, the input end of the offshore wind power base 200 is connected to the first output end of a preset offshore hydrogen-ammonia-alcohol base 100, and is used to provide offshore wind power resources, and in islanded operation and when wind power is abundant, connect to a preset hydrogen electrolyzer to prepare hydrogen.

[0034] In the embodiments of the present application, the input end of the offshore wind power base 200 is first connected to the first output end of the offshore hydrogen-ammonia-alcohol base 100, so that not only can offshore wind power resources be provided, but also in the case of islanded operation and abundant wind power, the offshore wind power base 200 can be connected to a hydrogen electrolyzer to produce hydrogen, providing an important and clean raw material source for the subsequent production of methanol, etc. in the offshore hydrogen-ammonia-alcohol base.

[0035] Optionally, in an embodiment of the present application, the offshore wind power base 200 includes: multiple grid-forming wind turbines and a wind turbine control device.

[0036] Among them, the wind turbine control device is connected in parallel with the multiple grid-forming wind turbines, and is used to obtain the wind speed information corresponding to the offshore wind power base 200 during normal operation, determine the type of grid-forming wind turbine to be operated according to the wind speed information, and distribute the active power and reactive power generated by the multiple wind turbines in the offshore wind power base 200 through the wind turbine control device. Among them, the types of grid-forming wind turbines include doubly-fed wind turbines and direct-drive wind turbines.

[0037] It should be noted that the offshore wind power base 200 in the embodiments of the present application can be composed of multiple doubly-fed and direct-drive wind turbines and a wind turbine control device connected in parallel. During normal operation, the embodiments of the present application can determine whether to operate a doubly-fed wind turbine or a direct-drive wind turbine through the wind turbine control device according to the corresponding wind speed data; the wind turbine control device distributes the active power and reactive power generated by the multiple wind turbines in the wind power base. Among them, both the doubly-fed and direct-drive wind turbines in the wind power base in the embodiments of the present application are equipped with grid-forming energy storage converters and are grid-forming wind turbines.

[0038] Thus, the embodiments of the present application construct the offshore wind power base 200 through multiple grid-forming wind turbines and a wind turbine control device, thereby providing important technical support for the generation of offshore wind power energy.

[0039] The input end of the offshore photovoltaic base 300 is connected to the second output end of the offshore hydrogen-ammonia-alcohol base 100, and is used to provide offshore photovoltaic resources, and connect to a hydrogen electrolyzer to produce hydrogen in the case of islanded operation and abundant photovoltaic power.

[0040] The input end of the inverter station 400 is connected to the output end of the offshore photovoltaic base 300, and is used to convert the direct current output by the offshore photovoltaic base 300 into alternating current.

[0041] Furthermore, the embodiments of the present application can also construct the offshore photovoltaic base 300 to provide offshore photovoltaic resources, and output the alternating current corresponding to the offshore photovoltaic base 300 through an inverter; in addition, in the case of islanded operation and abundant photovoltaic power, the offshore photovoltaic base 300 is connected to a hydrogen electrolyzer to produce hydrogen.

[0042] Optionally, in an embodiment of the present application, the offshore photovoltaic base 300 includes: photovoltaic panels, which are used to obtain the solar energy resources of the offshore photovoltaic base 300 and convert the solar energy resources into offshore photovoltaic power resources.

[0043] It can be understood that the offshore photovoltaic base 300 in the embodiment of the present application is mainly constructed by photovoltaic panels, so as to obtain the solar energy resources of the offshore photovoltaic base 300 and convert them into offshore photovoltaic power resources.

[0044] Therefore, in the embodiment of the present application, the offshore photovoltaic base is constructed by photovoltaic panels, thus ensuring the realization of offshore wind-solar energy complementarity.

[0045] The offshore hydrogen-ammonia-alcohol base 100 is used to utilize the surplus electric energy and hydrogen of the offshore wind power base 200 and the offshore photovoltaic base 300 to prepare hydrogen-ammonia-alcohol, so as to provide raw material supply for target ships and distributed power generation units while realizing multi-energy complementary power generation with the offshore wind power base 200 and the offshore photovoltaic base 300.

[0046] During the actual execution process, as Figure 2 shown, under islanded operation, the offshore hydrogen-ammonia-alcohol base 100 in the embodiment of the present application can utilize the green hydrogen prepared by the offshore wind-solar base (i.e., the offshore wind power base 200 and the offshore photovoltaic base 300) to react with nitrogen to produce ammonia, and transport it from the offshore hydrogen-ammonia-alcohol base to the inland through pipelines for use as raw materials for ammonia blending in distributed power generation; in addition, the offshore hydrogen-ammonia-alcohol base 100 can also use the green hydrogen prepared by the offshore wind-solar base and the captured carbon dioxide to jointly prepare methanol, which can be directly used as raw material supply for offshore ships.

[0047] Therefore, the embodiment of the present application can realize multi-energy complementarity by using the offshore hydrogen-ammonia-alcohol base 100, and can utilize the surplus electric energy of the offshore wind-solar base to prepare hydrogen-ammonia-alcohol.

[0048] The energy storage power station 500 of the offshore wind-solar base, the first input end of the energy storage power station of the offshore wind-solar base is connected to the output end of the offshore wind power base 200, the second input end of the energy storage power station 500 of the offshore wind-solar base is connected to the output end of the inverter station 400, and the output end of the energy storage power station 500 of the offshore wind-solar base is connected to a preset first busbar, which is used to smooth the AC output power of the offshore wind power base 200 and the offshore photovoltaic base 300, and output or store the corresponding active power and reactive power according to the output power of the offshore wind power base 200 and the offshore photovoltaic base 300, so as to balance the power of the target power system.

[0049] The booster station 600, the input end of the booster station 600 is connected to the first busbar, and the output end of the booster station 600 is connected to a preset second busbar, which is used to increase the AC power output by the energy storage power station of the offshore wind-solar base to the target voltage level.

[0050] In an embodiment of the present application, the second input end and the output end of the energy storage power station 500 of the offshore wind and solar base are respectively connected to the output end of the inverter station 400 and the first busbar (i.e., the 35 kV busbar) to smooth the output of the alternating current generated by the offshore wind and solar base and obtain an alternating current close to a sine wave. At the same time, the energy storage power station 500 of the offshore wind and solar base can also output or store corresponding active power and reactive power according to the active power and reactive power output by the offshore wind and solar base (i.e., the offshore wind power base 200 and the offshore photovoltaic base 300). For example, when the active power and reactive power output by the offshore wind and solar base are large, the energy storage power station 500 of the offshore wind and solar base can store the corresponding active power and reactive power. When the active power and reactive power output by the offshore wind and solar base are small, the energy storage power station 500 of the offshore wind and solar base can output a certain amount of active power and reactive power, so as to make the target power system reach power balance. In addition, the embodiment of the present application can also adjust the reactive power through the energy storage power station 500 of the offshore wind and solar base to quickly adjust the voltage.

[0051] Furthermore, in the embodiment of the present application, the input end and the output end of the step-up substation 600 can be respectively connected to the first busbar and the second busbar (i.e., the 220 kV busbar), so as to increase the voltage level of the alternating current output by the energy storage power station 500 of the offshore wind and solar base to a preset level (i.e., the target voltage level).

[0052] Optionally, in an embodiment of the present application, the energy storage power station 500 of the offshore wind and solar base includes: a lithium iron phosphate and lithium titanate battery cabin composed of a preset lithium iron phosphate battery system, a lithium titanate battery system, a battery control cabinet, a battery power supply cabinet, a battery management system, an energy management system, and a grid-connected inverter, which is used to smooth the output of the offshore wind power base and the offshore photovoltaic base and balance the active power and reactive power of the system. The lithium iron phosphate battery system and the lithium titanate battery system include multiple groups of lithium iron phosphate and lithium titanate battery packs connected in parallel, and the lithium iron phosphate and lithium titanate battery packs are composed of lithium iron phosphate batteries and lithium titanate batteries connected in series.

[0053] It should be noted that the energy storage power station 500 of the offshore wind and solar base in the embodiment of the present application includes a lithium iron phosphate and lithium titanate battery cabin, which mainly includes a lithium iron phosphate battery system, a lithium titanate battery system, a battery control cabinet, a battery power supply cabinet, a battery management system, an energy management system, and a grid-connected inverter.

[0054] In an embodiment of the present application, the lithium iron phosphate battery system and the lithium titanate battery system include multiple groups of lithium iron phosphate and lithium titanate battery packs connected in parallel, and the lithium iron phosphate and lithium titanate battery packs can be composed of lithium iron phosphate batteries and lithium titanate batteries connected in series; in the actual implementation process, the lithium iron phosphate and lithium titanate battery compartments in the embodiments of the present application can be used to smooth the output of the wind-solar base, balance the active power and reactive power of the system, and adjust the reactive power through the offshore wind-solar base energy storage power station 500 to achieve rapid voltage regulation.

[0055] Therefore, the embodiment of the present application forms an offshore wind-solar base energy storage power station through the lithium iron phosphate and lithium titanate battery compartments to smooth the output of the wind-solar base, and balance the active power and reactive power of the system by adjusting the active power and reactive power of the battery packs in the battery compartments.

[0056] The input end of the grid-forming energy storage phase-shifting power station 700 is connected to the second busbar, and the output end of the grid-forming energy storage phase-shifting power station 700 is connected to a preset third busbar, which is used to perform preset grid-forming and phase-shifting operations on alternating current of a target voltage level to generate the target alternating current after grid-forming, and perform corresponding broadband impedance scanning operations on the target alternating current to obtain the full-network impedance, and based on the full-network impedance, judge whether there is an oscillation risk for the target alternating current.

[0057] The input end of the broadband oscillation control and prevention device 800 is connected to the third busbar, which is used to perform preset broadband oscillation prevention operations when there is an oscillation risk for the target alternating current. Among them, the grid-forming static compensator group and the grid-forming unified power flow controller group in the broadband oscillation control and prevention device have impedance regulation functions and grid-forming attributes.

[0058] After that, the embodiment of the present application can also connect the grid-forming energy storage phase-shifting power station 700 to the third busbar (i.e., the 500KV busbar), which can be used to perform grid-forming and phase-shifting operations to obtain the target alternating current after grid-forming (i.e., the alternating current with a preset frequency and grid-forming attributes), and perform oscillation detection on the target alternating current.

[0059] As a feasible method, the embodiment of the present application can utilize the broadband impedance scanning function of the grid-forming energy storage phase-shifting controller to scan the full-network impedance through 0.1~2500HZ to obtain the full-network impedance, and based on the full-network impedance, judge whether there is an oscillation risk through a criterion.

[0060] Furthermore, the embodiment of the present application can also set a broadband oscillation control and prevention device 800 connected to the third busbar to perform broadband oscillation prevention operations when there is an oscillation risk for the target alternating current.

[0061] Optionally, in an embodiment of the present application, the grid-forming energy storage phase regulating power station 700 includes: a plurality of multi-energy storage units, a plurality of synchronous phase modifiers, a synchronous phase modifier group, a plurality of grid-forming energy storage converters, a plurality of energy storage modules, an energy storage module group, and a plurality of grid-forming energy storage phase regulating controllers.

[0062] Among them, the synchronous phase modifier group is composed of a plurality of synchronous phase modifiers connected in series; the input ends of the plurality of grid-forming energy storage converters are connected to the output ends of the plurality of multi-energy storage units, and are used to provide target alternating current with a preset frequency and grid-forming attributes by using a preset grid-forming control strategy; the plurality of energy storage modules are composed of a plurality of multi-energy storage units and a plurality of grid-forming energy storage converters; the energy storage module group is composed of a plurality of energy storage modules connected in series.

[0063] The output ends of each phase of the grid-forming energy storage phase regulating controllers among the plurality of grid-forming energy storage phase regulating controllers are connected to the input ends of the synchronous phase modifier group, and the input ends of each phase of the grid-forming energy storage phase regulating controllers are connected to the energy storage module group, and are used to coordinately control the energy storage module group and the synchronous phase modifier group to perform primary, secondary, and tertiary frequency modulation and voltage regulation, as well as regulation operations of active power, reactive power, and short-circuit capacity.

[0064] It should be noted that as Figure 3 shown, the grid-forming energy storage phase regulating power station 700 (I) in the embodiment of the present application is mainly composed of N energy storage modules, N synchronous phase modifiers, and each phase of grid-forming energy storage phase regulating controllers composed of N multi-energy storage units and N grid-forming energy storage converters.

[0065] Among them, the multi-energy storage unit mainly includes a sodium-ion battery pack, a supercapacitor pack, and a hydrogen storage device; the grid-forming energy storage converter can use grid-forming control to provide alternating current with a preset frequency and grid-forming attributes (i.e., the target alternating current after grid-forming); when accessing at a low short-circuit ratio, the synchronous phase modifier in the grid-forming energy storage phase regulating power station (I) can be used to provide short-circuit capacity to improve system stability; as Figure 3 shown, among them, synchronous phase modifier (I) represents the I-th synchronous phase modifier, synchronous phase modifier (N) represents the N-th synchronous phase modifier, and their sodium-ion battery pack, supercapacitor pack, hydrogen storage device, and grid-forming energy storage converter represent similar meanings, which will not be elaborated here.

[0066] In addition, as Figure 2 shown, the grid-forming energy storage phase regulating controller in the embodiment of the present application can control the multi-energy storage unit, the grid-forming energy storage converter, and the synchronous phase modifier to coordinately control the multi-energy storage unit to provide active power response to the power grid for primary, secondary, and tertiary frequency modulation, and to coordinate the plurality of energy storage modules and the synchronous phase modifier to perform frequency modulation, voltage regulation, active power, reactive power, and short-circuit capacity regulation.

[0067] Therefore, in the embodiments of the present application, the grid-forming energy storage phase modulation controller can control the grid-forming energy storage converter to adjust multiple preset parameters for primary frequency modulation, secondary frequency modulation, tertiary frequency modulation, and voltage regulation, and can adjust the active power and reactive power provided by the sodium-ion battery, supercapacitor, and hydrogen storage device.

[0068] Therefore, the embodiments of the present application construct a grid-forming energy storage phase modulation power station through multiple energy storage modules composed of multiple multi-energy storage units and multiple grid-forming energy storage converters, multiple synchronous condensers, and a grid-forming energy storage phase modulation controller, so as to be able to conduct research on grid-forming energy storage control for a multi-energy complementary base of offshore wind, light, hydrogen, ammonia, and alcohol under low short-circuit ratio access conditions, providing reliable technical guidance and basis for the optimization regulation and oscillation control of the power grid.

[0069] Optionally, in an embodiment of the present application, when accessing under a low short-circuit ratio, the synchronous condenser in the grid-forming energy storage phase modulation power station is used to provide short-circuit capacity.

[0070] In the embodiments of the present application, the connection modes of the energy storage module group, synchronous condenser group, and each-phase energy storage phase modulation controller in the grid-forming energy storage phase modulation power station are as Figure 4 shown. It can be understood that under the condition of low short-circuit ratio access, the embodiments of the present application can use the synchronous condenser in the grid-forming energy storage phase modulation power station to provide short-circuit capacity, thereby improving the system stability.

[0071] Optionally, in an embodiment of the present application, the multi-energy storage unit includes: a sodium-ion battery pack, a supercapacitor pack, and a hydrogen storage device.

[0072] Among them, the supercapacitor pack is used to provide inertia support for instantaneous energy storage.

[0073] The sodium-ion battery pack is used to perform energy storage operations that meet the requirements of the first preset duration.

[0074] The hydrogen storage device is used to perform energy storage operations that meet the requirements of the second preset duration.

[0075] During the actual execution process, as Figure 3 shown, the multi-energy storage unit in the embodiments of the present application is mainly composed of a sodium-ion battery pack, a supercapacitor pack, and a hydrogen storage device.

[0076] Among them, the sodium-ion battery pack, supercapacitor pack, and hydrogen storage device are connected in parallel and are all connected to the grid-forming energy storage converter.

[0077] The supercapacitor can provide inertia support for instantaneous energy storage; the sodium-ion battery pack can perform short-term energy storage (i.e., meet the requirements of the first preset duration); the hydrogen storage device can perform long-term energy storage (i.e., meet the requirements of the second preset duration); the sodium-ion battery pack, the supercapacitor, and the hydrogen storage device can perform active power control, frequency control, and voltage control through a grid-forming energy storage converter.

[0078] Thus, the embodiments of the present application form a multi-energy storage unit by using a sodium-ion battery pack, a supercapacitor bank, and a hydrogen storage device, thereby providing hardware support for electric energy storage and ensuring the reliability of the subsequent construction of a grid-forming energy storage phase-shifting power station.

[0079] Optionally, in an embodiment of the present application, the wide-frequency oscillation control and prevention device 800 includes: a virtual impedance control system, a grid-forming unified power flow controller group, and a grid-forming static compensator group.

[0080] Among them, the virtual impedance control system is used to determine whether increasing or decreasing the impedance will continue to cause oscillations when there is an oscillation risk in the target alternating current. Among them, when increasing or decreasing the impedance will not continue to cause oscillations, the parameters of the preset PID controller are adjusted to regulate the impedance.

[0081] The grid-forming unified power flow controller group and the grid-forming static compensator group are used to adjust the parameters of the PID controller to regulate the impedance until no oscillations occur when increasing or decreasing the impedance will continue to cause oscillations.

[0082] In the specific implementation process, the wide-frequency oscillation control and prevention device mainly includes a virtual impedance control system, a grid-forming unified power flow controller group, and a grid-forming static compensator group.

[0083] When the target alternating current will oscillate (i.e., there is an oscillation risk), the embodiments of the present application can call the virtual impedance control system to determine whether the increased or decreased impedance (i.e., the virtual impedance) will still cause oscillations; if it will still cause oscillations, then call the grid-forming static compensator group and the grid-forming unified power flow controller group to adjust the parameters of the PID controller to achieve the regulation of the virtual impedance until no oscillations occur; otherwise, there is no need to call the grid-forming static compensator group and the grid-forming unified power flow controller group.

[0084] Thus, the embodiments of the present application construct a wide-frequency oscillation control and prevention device through a virtual impedance control system, a grid-forming unified power flow controller group, and a grid-forming static compensator group, thereby realizing voltage, frequency, short-circuit capacity adjustment, and inertia support, and can perform oscillation prevention.

[0085] Optionally, in an embodiment of the present application, the network-forming static var compensator group and the network-forming unified power flow controller group have network-forming attributes. By adjusting the reactive power in the network-forming static var compensator group, the voltage amplitude is adjusted, and by adjusting the network-forming unified power flow controller group, the voltage amplitude and phase angle are adjusted.

[0086] It should be noted that the network-forming static var compensator group and the network-forming unified power flow controller group in the embodiments of the present application not only have the impedance regulation function but also have network-forming attributes, and can adjust the voltage amplitude and the voltage phase angle by adjusting the reactive power in the network-forming static var compensator group and adjusting the network-forming unified power flow controller group.

[0087] Thus, the embodiments of the present application utilize the network-forming static var compensator group and the network-forming unified power flow controller group with impedance regulation function and network-forming attributes to adjust the voltage amplitude and the voltage phase angle of the voltage, achieving the optimized regulation of grid support and oscillation suppression.

[0088] The network-forming control system for the offshore wind-solar-hydrogen-ammonia-alcohol base proposed according to the embodiments of the present application includes an offshore hydrogen-ammonia-alcohol base, an offshore wind power base, an offshore photovoltaic base, an inverter station, an offshore wind-solar base energy storage power station, a booster station, a network-forming energy storage phase regulating power station, and a wide-frequency oscillation control and prevention device. Thus, research on the network-forming energy storage control of the offshore wind-solar-hydrogen-ammonia-alcohol multi-energy complementary base can be carried out under low short-circuit ratio access and islanded operation, achieving voltage, frequency, short-circuit capacity adjustment, and inertia support, and oscillation prevention can be carried out, achieving the optimized regulation of grid support and oscillation suppression; at the same time, multi-energy complementarity is realized, the energy utilization rate is improved, and hydrogen-ammonia-alcohol can be prepared from green energy, reducing carbon emissions. Through the offshore photovoltaic base, inverter station, offshore hydrogen-ammonia-alcohol base, network-forming energy storage phase regulating power station, offshore wind-solar base energy storage power station, booster station, etc., the present application can carry out research on the network-forming control and wide-frequency oscillation prevention method of the offshore wind-solar-hydrogen-ammonia-alcohol multi-energy complementary base under low short-circuit ratio access and islanded operation, thereby being able to realize multi-energy complementarity, improve the energy utilization rate, and prepare hydrogen-ammonia-alcohol from green energy, reducing carbon emissions.

[0089] Secondly, a wide-frequency oscillation prevention method for the network-forming control system of the offshore wind-solar-hydrogen-ammonia-alcohol base proposed according to the embodiments of the present application is described with reference to the accompanying drawings.

[0090] Figure 5 It is a flowchart of a wide-frequency oscillation prevention method for a network-forming control system of an offshore wind-solar-hydrogen-ammonia-alcohol base provided by an embodiment of the present application.

[0091] As Figure 5 shown, the wide-frequency oscillation prevention method for the network-forming control system of the offshore wind-solar-hydrogen-ammonia-alcohol base includes the following steps: In step S501, the preset offshore wind power base and offshore photovoltaic base are used to provide offshore wind power resources and offshore photovoltaic power resources. In the case of islanded operation and abundant wind power, the preset hydrogen electrolyzer is connected to produce hydrogen.

[0092] In step S502, based on the preset offshore hydrogen-ammonia-alcohol base, the surplus electric energy and hydrogen of the offshore wind power base and offshore photovoltaic base are used to produce hydrogen-ammonia-alcohol, so as to provide multi-energy complementary power generation with the offshore wind power base and offshore photovoltaic base, and at the same time provide raw material supply for target vessels and distributed power generation units.

[0093] In step S503, the direct current output by the offshore photovoltaic base is converted into alternating current, and the output of the alternating current generated by the offshore wind power base and offshore photovoltaic base is smoothed. According to the output power of the offshore wind power base and offshore photovoltaic base, the corresponding active power and reactive power are output or stored to balance the power of the target power system.

[0094] In step S504, the alternating current output by the energy storage power station of the offshore wind-solar base is increased to the target voltage level. The network-forming energy storage phase modulation power station performs preset network-forming and phase modulation operations on the alternating current of the target voltage level to generate the target alternating current after network-forming, and performs a broadband impedance scan operation of 0.1~2500HZ on the target alternating current to obtain the full network impedance. Based on the full network impedance, it is judged whether there is an oscillation risk in the target alternating current, so as to perform a preset broadband oscillation prevention operation in the case of an oscillation risk in the target alternating current.

[0095] It should be noted that the foregoing explanation of the embodiment of the network-forming control device of the offshore wind-solar-hydrogen-ammonia-alcohol multi-energy complementary base is also applicable to the broadband oscillation prevention method of the network-forming control system of the offshore wind-solar-hydrogen-ammonia-alcohol base in this embodiment, which will not be elaborated here.

[0096] The broadband oscillation prevention and control method for the grid-forming control system of an offshore wind-solar-hydrogen-ammonia-alcohol base proposed according to the embodiments of the present application provides offshore wind power resources and offshore photovoltaic resources through a preset offshore wind power base and an offshore photovoltaic base, and connects a preset hydrogen electrolyzer under the conditions of islanded operation and abundant wind power to produce hydrogen; based on the preset offshore hydrogen-ammonia-alcohol base, uses the surplus electric energy and hydrogen of the offshore wind power base and the offshore photovoltaic base to produce hydrogen-ammonia-alcohol, so as to carry out multi-energy complementary power generation with the offshore wind power base and the offshore photovoltaic base while providing raw material supply for target ships; converts the direct current output by the offshore photovoltaic base into alternating current; smooths the output of the alternating current generated by the offshore wind power base and the offshore photovoltaic base, and outputs or stores the corresponding active power and reactive power according to the output power of the offshore wind power base and the offshore photovoltaic base to balance the power of the target power system, and can also adjust the reactive power through the energy storage power station of the offshore wind-solar base to quickly adjust the voltage; then, the embodiments of the present application can increase the alternating current output by the energy storage power station of the offshore wind-solar base to the target voltage level, and perform preset grid-forming and phase adjustment operations on the alternating current of the target voltage level through a grid-forming energy storage phase adjustment power station to generate the target alternating current after grid-forming, and perform corresponding broadband impedance scanning operations on the target alternating current to obtain the full network impedance, and based on the full network impedance, judge whether the target alternating current has an oscillation risk, so as to perform preset broadband oscillation prevention and control operations in the case that the target alternating current has an oscillation risk. Through the offshore photovoltaic base, the inverter station, the offshore hydrogen-ammonia-alcohol base, the grid-forming energy storage phase adjustment power station, the energy storage power station of the offshore wind-solar base, the booster station, etc., the present application can conduct research on the grid-forming control and broadband oscillation prevention and control method of the offshore wind-solar-hydrogen-ammonia-alcohol multi-energy complementary base under low short-circuit ratio access and islanded operation, so as to achieve multi-energy complementarity, improve the energy utilization rate, and can produce hydrogen-ammonia-alcohol with green energy, reducing carbon emissions.

[0097] In the description of this specification, the descriptions referring to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any one or N embodiments or examples in a suitable manner. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0098] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In the description of the present application, the meaning of "N" is at least two, such as two, three, etc., unless otherwise specifically defined.

[0099] Any process or method description depicted in a flowchart or otherwise described herein may be understood to represent a module, segment, or portion of code including one or N executable instructions for implementing a customized logical function or process, and the scope of the preferred embodiments of the present application includes additional implementations, where the functions may be performed in an order not shown or discussed, including in a substantially simultaneous manner according to the functions involved or in a reverse order, which should be understood by those skilled in the art to which the embodiments of the present application pertain.

Claims

1. A grid-forming control system for an offshore wind-solar-hydrogen-ammonia-alcohol base, characterized in that, Including: An offshore wind power base, the input end of the offshore wind power base is connected to the first output end of a preset offshore hydrogen-ammonia-alcohol base, for providing offshore wind power resources, and in the case of islanded operation and high wind power generation, connecting to a preset hydrogen electrolyzer to produce hydrogen; An offshore photovoltaic base, the input end of the offshore photovoltaic base is connected to the second output end of the offshore hydrogen-ammonia-alcohol base, for providing offshore photovoltaic power resources, and in the case of islanded operation and high photovoltaic power generation, connecting to the hydrogen electrolyzer to produce hydrogen; An offshore hydrogen-ammonia-alcohol base, for using the surplus electric energy and hydrogen of the offshore wind power base and the offshore photovoltaic base to produce hydrogen-ammonia-alcohol, so as to carry out multi-energy complementary power generation with the offshore wind power base and the offshore photovoltaic base, and at the same time provide raw material supply for target ships and distributed power generation units; An inverter station, the input end of the inverter station is connected to the output end of the offshore photovoltaic base, for converting the direct current output by the offshore photovoltaic base into alternating current; An offshore wind-solar base energy storage power station, the first input end of the offshore wind-solar base energy storage power station is connected to the output end of the offshore wind power base, the second input end of the offshore wind-solar base energy storage power station is connected to the output end of the inverter station, and the output end of the offshore wind-solar base energy storage power station is connected to a preset first busbar, for smoothing the alternating current output of the offshore wind power base and the offshore photovoltaic base, and outputting or storing corresponding active power and reactive power according to the output power of the offshore wind power base and the offshore photovoltaic base, so as to balance the power of the target power system; A booster station, the input end of the booster station is connected to the first busbar, and the output end of the booster station is connected to a preset second busbar, for boosting the alternating current output by the offshore wind-solar base energy storage power station to the target voltage level; A grid-forming energy storage phase-shifting power station, the input end of the grid-forming energy storage phase-shifting power station is connected to the second busbar, and the output end of the grid-forming energy storage phase-shifting power station is connected to a preset third busbar, for performing preset grid-forming and phase-shifting operations on the alternating current of the target voltage level to generate the target alternating current after grid-forming, and performing corresponding broadband impedance scanning operations on the target alternating current to obtain the full network impedance, and based on the full network impedance, judging whether the target alternating current has an oscillation risk; A broadband oscillation control and prevention device, the input end of the broadband oscillation control and prevention device is connected to the third busbar, for performing preset broadband oscillation prevention operations in the case that the target alternating current has the oscillation risk, wherein the grid-forming static compensator bank and the grid-forming unified power flow controller bank in the broadband oscillation control and prevention device have impedance regulation functions and grid-forming attributes.

2. The grid-forming control system of the offshore wind-solar-hydrogen-ammonia-alcohol base according to claim 1, wherein, The grid-forming energy storage phase-shifting power station includes: Multiple multi-energy storage units; Multiple synchronous phase modifiers; A synchronous phase modifier group composed of the series connection of the multiple synchronous phase modifiers; Multiple network-forming energy storage converters, the input ends of the multiple network-forming energy storage converters are connected to the output ends of the multiple multi-energy storage units, and are used to provide target alternating current with a preset frequency and network-forming attributes by using a preset network-forming control strategy; Multiple energy storage modules composed of the multiple multi-energy storage units and the multiple network-forming energy storage converters; An energy storage module group formed by connecting the multiple energy storage modules in series; Multiple network-forming energy storage phase modulation controllers, the output ends of each phase of the network-forming energy storage phase modulation controllers are connected to the input ends of the synchronous phase modifier group, and the input ends of each phase of the network-forming energy storage phase modulation controllers are connected to the energy storage module group, and are used to coordinately control the energy storage module group and the synchronous phase modifier group to perform primary, secondary, and tertiary frequency modulation and voltage regulation, as well as regulation operations of active power, reactive power, and short-circuit capacity.

3. The grid-connected control system of the offshore wind-solar-hydrogen-ammonia-alcohol base according to claim 2, wherein The multi-energy storage unit includes: A supercapacitor bank, which is used to provide inertia support for instantaneous energy storage; A sodium-ion battery bank, which is used to perform energy storage operations that meet the requirements of the first preset duration; A hydrogen storage device, which is used to perform energy storage operations that meet the requirements of the second preset duration.

4. The grid-forming control system for an offshore wind-solar-hydrogen-ammonia-alcohol base according to claim 2, wherein When connected with a low short-circuit ratio, the synchronous phase modifier in the network-forming energy storage phase modulation power station is used to provide short-circuit capacity.

5. The grid-forming control system of the offshore wind-solar-hydrogen-ammonia-alcohol base according to claim 1, characterized in that, The offshore wind power base includes: Multiple network-forming wind turbines; A wind turbine control device, the wind turbine control device is connected in parallel with the multiple network-forming wind turbines, and is used to obtain the wind speed information corresponding to the offshore wind power base during normal operation, determine the type of network-forming wind turbine to be operated according to the wind speed information, and distribute the active power and reactive power generated among the multiple wind turbines in the offshore wind power base through the wind turbine control device, wherein the type of network-forming wind turbine includes a doubly-fed wind turbine and a direct-drive wind turbine.

6. The grid-forming control system of the offshore wind-solar-hydrogen-ammonia-alcohol base according to claim 1, characterized in that, The offshore photovoltaic base includes: Photovoltaic panels, which are used to obtain the solar energy resources of the offshore photovoltaic base and convert the solar energy resources into offshore photovoltaic power resources.

7. The grid-forming control system of the offshore wind-solar-hydrogen-ammonia-alcohol base according to claim 1, characterized in that, The offshore wind-solar base energy storage power station includes: A lithium iron phosphate and lithium titanate battery cabin composed of a preset lithium iron phosphate battery system, a lithium titanate battery system, a battery control cabinet, a battery power supply cabinet, a battery management system, an energy management system, and a grid-following converter, which is used to smooth the output of the offshore wind power base and the offshore photovoltaic base and balance the active power and reactive power of the system. Among them, the lithium iron phosphate battery system and the lithium titanate battery system include multiple groups of lithium iron phosphate and lithium titanate battery packs connected in parallel, and the lithium iron phosphate and lithium titanate battery packs are composed of lithium iron phosphate batteries and lithium titanate batteries connected in series.

8. The grid-forming control system of the offshore wind-solar-hydrogen-ammonia-alcohol base according to claim 1, characterized in that, The broadband oscillation control and prevention device includes: A virtual impedance control system, which is used to judge whether increasing or decreasing the impedance will continue to cause oscillation when there is an oscillation risk in the target alternating current. Among them, when increasing or decreasing the impedance will not continue to cause oscillation, the parameters of a preset PID controller are adjusted to regulate the impedance; The network-forming unified power flow controller group and the network-forming static compensator group are used to adjust the parameters of the PID controller to regulate the impedance when increasing or decreasing the impedance will continue to cause oscillation until no oscillation occurs.

9. The grid-forming control system of the offshore wind-solar-hydrogen-ammonia-alcohol base according to claim 1, characterized in that, The network-forming static compensator group and the network-forming unified power flow controller group have network-forming attributes. By adjusting the reactive power in the network-forming static compensator group, the voltage amplitude is adjusted. By adjusting the network-forming unified power flow controller group, the voltage amplitude and phase angle are adjusted.

10. A method for preventing and controlling broadband oscillations in the grid-forming control system of an offshore wind-solar-hydrogen-ammonia-alcohol base, characterized in that, It includes the following steps: Provide offshore wind power resources and offshore photovoltaic resources through a preset offshore wind power base and offshore photovoltaic base, and connect a preset hydrogen electrolyzer in the case of islanded operation and high wind power generation to produce hydrogen; Based on a preset offshore hydrogen-ammonia-alcohol base, use the excess electric energy and the hydrogen of the offshore wind power base and the offshore photovoltaic base to produce hydrogen-ammonia-alcohol, so as to carry out multi-energy complementary power generation with the offshore wind power base and the offshore photovoltaic base, and at the same time provide raw material supply for target ships and distributed power generation units; Convert the direct current output by the offshore photovoltaic base into alternating current, smooth the alternating current output of the offshore wind power base and the offshore photovoltaic base, and output or store the corresponding active power and reactive power according to the output power of the offshore wind power base and the offshore photovoltaic base to balance the power of the target power system; Raise the alternating current output by the offshore wind-solar base energy storage power station to the target voltage level, perform preset network-forming and phase adjustment operations on the alternating current of the target voltage level through a network-forming energy storage phase adjustment power station to generate the target alternating current after network-forming, and perform a broadband impedance scan operation of 0.1~2500HZ on the target alternating current to obtain the full network impedance, and based on the full network impedance, judge whether there is an oscillation risk in the target alternating current, so as to perform a preset broadband oscillation prevention operation in the case that the target alternating current has the oscillation risk.

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