Offshore virtual power plant AC / DC power supply system and method

Abstract

The invention relates to an offshore virtual power plant AC / DC power supply system and method, and the system comprises an offshore power unit which converts offshore renewable energy into electric energy based on various offshore power generation stations; the offshore energy storage unit is used for storing the electric energy generated by the power supply unit based on various offshore energy storage power stations; the offshore AC / DC power supply unit meets the power demands of various types of loads on the sea by using AC / DC power supply equipment; the offshore power supply sorting unit is used for carrying out power supply priority sorting on various types of loads on the sea based on the supply-demand relationship among the offshore power supply unit, the offshore energy storage unit and the various types of loads on the sea; the sea-land networking power supply unit is used for balancing the power demands of power grids of sea and land based on the power demands of various types of loads on the sea and the power supply capability of the sea power supply unit; the intelligent control unit comprises a data acquisition and monitoring module, an energy management module, a safety protection module and an information transmission communication module.

Description

Technical Field

[0001] The present invention relates to the technical field of source-grid-load-storage, and specifically to an AC-DC power supply system and method for an offshore virtual power plant. Background Technique

[0002] Currently, offshore wind power, offshore photovoltaic, and wave energy offshore power plants mainly adopt the development mode of separate construction and separate transmission to the onshore power grid. This mode has the problems of acting independently and isolated development. Due to the large differences in the output curves of various types of renewable energy, the aggregation and optimization of various resources cannot be achieved; the operation reliability and stability of separate power transmission of various power sources are relatively poor; and there are large power losses and resource wastes when offshore electric energy is transmitted to the onshore power grid over a long distance.

[0003] Offshore resource development mainly includes production activities such as offshore oil and gas exploitation, ocean ranching, and seawater hydrogen production. As an important power source, electric energy is mainly obtained in two ways offshore: (1) Building a fuel (gas) generator near the offshore load for power supply. This method causes a large amount of carbon emissions and environmental pollution; moreover, the operation reliability and stability of the isolated power supply system are relatively poor. (2) Obtaining electric energy by connecting to the onshore power grid through submarine cables. This method requires long-distance power supply from the onshore power grid, requires a large amount of line investment, and causes relatively large power losses.

[0004] Offshore resource development also involves various offshore transportation equipment such as ships. With the development of ship electrification, oil is gradually replaced by electricity. In order to maintain power, if a ship frequently returns to the port for charging through the onshore power grid-port shore power AC system, the navigation distance and working efficiency of the ship are restricted; moreover, part of the electric energy charged by the ship may come from the long-distance transmission of offshore power to the onshore power grid and is only utilized when the ship sails to the sea, which cannot achieve the near utilization of offshore resources and also causes power losses. On the other hand, the number of ships driven by direct current is increasing continuously. In order for such ships to interface with the AC interface of the port shore power, additional AC-DC conversion equipment and interfaces need to be configured, increasing the equipment investment, space occupation, and charging inconvenience of the ship.

[0005] The Chinese invention patent with the patent publication number CN116961087A discloses a charging price formulation strategy based on an optimal charging and discharging strategy, which includes an offshore integrated power generation system; the offshore integrated power generation system is used for wind power generation and photovoltaic power generation and transmits the power to an offshore booster station; the offshore booster station is used for boosting the current output by the offshore integrated power generation system and then transmitting it to the intelligent control center in the onshore integrated control center; the intelligent control center in the onshore integrated control center is used for allocating and outputting the electric energy output by the offshore booster station to the onshore substation or to the onshore chemical energy storage system according to the preset control rules; the onshore substation is used for converting and transmitting the direct current output by the offshore booster station allocated by the intelligent control center to the power grid.

[0006] In the prior art, the electric energy provided by multiple offshore power sources is supplied to the inland to ensure the stability of the power grid operation. However, it does not consider that the offshore power consumption itself also requires electric energy to maintain. First, it is necessary to ensure the power consumption demand of the offshore load, and then realize the supply and supplement of the inland electric energy. At the same time, when allocating electric energy offshore, a reasonable allocation strategy is required; and in the prior art, there is no mention of setting up an energy storage center offshore, and the allocation and utilization of offshore electric energy are not convenient enough. Summary of the Invention

[0007] In order to solve the problems existing in the above prior art, the present invention proposes an AC-DC power supply system and method for an offshore virtual power plant.

[0008] The technical solution of the present invention is as follows:

[0009] On the one hand, the present invention proposes an AC-DC power supply system for an offshore virtual power plant, including:

[0010] An offshore power supply unit that converts offshore renewable energy into electric energy based on various offshore power generation power plants; the various offshore power generation power plants include offshore wind power, offshore photovoltaic, and wave energy offshore power generation power plants;

[0011] An offshore energy storage unit that stores the electric energy generated by the power supply unit based on various offshore energy storage power plants; the various offshore energy storage power plants include island pumped storage, electrochemical energy storage, and underwater compressed air offshore energy storage power plants;

[0012] An offshore AC-DC power supply unit that uses AC-DC power supply equipment to meet the power consumption needs of various types of offshore loads;

[0013] An offshore power supply ranking unit that ranks the power supply priorities of various types of offshore loads based on the supply-demand relationship between the offshore power supply unit, the offshore energy storage unit, and various types of offshore loads;

[0014] The sea-land interconnected power supply unit balances the power consumption demands of the power grids in both the sea and land areas based on the power consumption demands of various types of loads at sea and the power supply capabilities of the offshore power supply units.

[0015] The intelligent control unit includes a data acquisition and monitoring module, an energy management module, a safety protection module, and an information transmission and communication module; it is used to coordinate the optimal operation modes of the offshore power supply unit, the offshore energy storage unit, and the offshore AC / DC power supply unit, and achieve the optimal scheduling among the units.

[0016] As a preferred implementation mode, the AC / DC power supply equipment includes DC power supply equipment, industrial frequency AC power supply equipment, and non-industrial frequency AC power supply equipment, and the interfaces with the charging equipment of various types of loads at sea are made universal and standardized.

[0017] As a preferred implementation mode, the various types of loads at sea include offshore oil and gas exploitation, offshore aquaculture, seawater hydrogen production, and charging of various types of ships. Among them, the charging of various types of ships has the highest power supply priority.

[0018] As a preferred implementation mode, the specific steps for sorting the power supply priorities of various types of loads at sea based on the supply-demand relationship between the offshore power supply unit, the offshore energy storage unit, and various types of loads at sea are as follows:

[0019] When the total generated electric energy of the offshore power supply unit is greater than the power consumption demands of various types of loads at sea, the offshore virtual power plant first supplies power to all offshore loads, and then stores the surplus electric energy in the offshore energy storage unit. The specific calculation formula is as follows:

[0020]

[0021] In the formula, F is the generated electric energy of the offshore power supply, i is the serial number of the offshore power supply, and m is the total number of offshore power supplies; L is the power consumption of various types of loads at sea, k is the serial number of various types of loads at sea, and s is the number of various types of loads at sea.

[0022] When the total generated electric energy of the offshore power supply unit is less than the power consumption demands of various types of loads at sea and greater than or equal to the power consumption demands of the ship loads, the offshore virtual power plant gives priority to supplying power to the ship loads, and the remaining generated electric energy and the stored electric energy in the energy storage unit jointly supply power to other offshore loads. The specific calculation formula is as follows:

[0023]

[0024] In the formula, B(h) is the power consumption of the ship load, h is the ship serial number, and t is the number of ships.

[0025] When the total generated electric energy of the offshore power unit is less than the electricity demand of the ship load, the offshore virtual power plant will preferentially supply the electricity demand of the ship load with the total generated electric energy and the stored electric energy; if there is an electric energy surplus, it will supply some other offshore loads at the same time, in accordance with the priority order of the remaining various offshore loads; if the electric energy is still insufficient, it will be charged in sequence according to the time sequence when the ship arrives at the offshore virtual power plant. The specific calculation formula is as follows:

[0026]

[0027] As a preferred embodiment, the steps of balancing the electricity demands of the power grids on both sides of the sea based on the electricity demands of various types of offshore loads and the power supply capacity of the offshore power unit are specifically as follows:

[0028] When the total generated electric energy of the offshore power unit is greater than the sum of the total offshore load and the total offshore energy storage, the surplus electric energy will be sent to the onshore power grid or other offshore virtual power plants. The specific judgment formula is as follows:

[0029]

[0030] When the sum of the total generated electric energy of the offshore power unit and the total offshore energy storage is less than the total offshore load, the onshore power grid or other offshore virtual power plants will supply supplementary power. The specific judgment formula is as follows:

[0031]

[0032] When the total generated electric energy of the offshore power unit is greater than or equal to the total offshore load and less than or equal to the sum of the total offshore load and the total offshore energy storage, the offshore virtual power plant is in a self-balanced state and does not need to supply power to each other with the onshore power grid or other offshore virtual power plants. The specific judgment formula is as follows:

[0033]

[0034] On the other hand, the present invention proposes an AC-DC power supply method for an offshore virtual power plant. The specific steps include:

[0035] Converting offshore renewable energy into electric energy based on various types of offshore power generation stations; the various types of offshore power generation stations include offshore wind power, offshore photovoltaic power, and wave energy offshore power generation stations;

[0036] Storing the electric energy generated by the power unit based on various types of offshore energy storage stations; the various types of offshore energy storage stations include island pumped storage, electrochemical energy storage, and underwater compressed air offshore energy storage stations;

[0037] Using AC-DC power supply equipment to meet the electricity demands of various types of offshore loads;

[0038] Based on the supply-demand relationship among the offshore power unit, offshore energy storage unit and various types of offshore loads, prioritize the power supply to various types of offshore loads;

[0039] Based on the electricity consumption demand of various types of offshore loads and the power supply capacity of the offshore power unit, balance the electricity consumption demand of the onshore and offshore power grids;

[0040] Construct an intelligent control unit, including a data acquisition and monitoring module, an energy management module, a safety protection module and an information transmission and communication module; used to coordinate the optimal operation modes of the offshore power unit, offshore energy storage unit and offshore AC / DC power supply unit, and achieve the optimal scheduling among the units.

[0041] As a preferred implementation mode, the AC / DC power supply equipment includes DC power supply equipment, industrial frequency AC power supply equipment and non-industrial frequency AC power supply equipment, and realizes the generalization and standardization of the charging equipment interfaces for various types of offshore loads.

[0042] As a preferred implementation mode, the various types of offshore loads include offshore oil and gas exploitation, offshore ranching, seawater hydrogen production and charging of various types of ships. Among them, the power supply priority of charging of various types of ships is the highest.

[0043] As a preferred implementation mode, the step of prioritizing the power supply to various types of offshore loads based on the supply-demand relationship among the offshore power unit, offshore energy storage unit and various types of offshore loads is specifically as follows:

[0044] When the total generated electric energy of the offshore power unit is greater than the electricity consumption demand of various types of offshore loads, the offshore virtual power plant first supplies power to all offshore loads, and then stores the surplus electric energy in the offshore energy storage unit. The specific calculation formula is as follows:

[0045]

[0046] In the formula, F is the generated electricity of the offshore power source, i is the serial number of the offshore power source, and m is the total number of offshore power sources; L is the electricity consumption of various types of offshore loads, k is the serial number of various types of offshore loads, and s is the number of various types of offshore loads;

[0047] When the total generated electric energy of the offshore power unit is less than the electricity consumption demand of various types of offshore loads and greater than or equal to the electricity consumption demand of the ship load, the offshore virtual power plant gives priority to supplying power to the ship load, and the remaining generated electric energy and stored electric energy jointly supply other offshore loads. The specific calculation formula is as follows:

[0048]

[0049] In the formula, B(h) is the electricity consumption of the ship load, h is the ship serial number, and t is the number of ships;

[0050] When the total generated electric energy of the offshore power unit is less than the power consumption demand of the ship load, the offshore virtual power plant preferentially supplies the power consumption demand of the ship load with the total generated electric energy and the energy stored in the energy storage; if there is an electric energy surplus, it supplies power to some other offshore loads at the same time, in accordance with the priority order of the remaining various offshore loads; if the electric energy is still insufficient, it charges in sequence according to the time sequence when the ship arrives at the offshore virtual power plant. The specific calculation formula is as follows:

[0051]

[0052] As a preferred implementation mode, the steps of balancing the power consumption demands of the power grids in the sea and on the land based on the power consumption demands of various types of offshore loads and the power supply capacity of the offshore power unit are specifically as follows:

[0053] When the total generated electric energy of the offshore power unit is greater than the sum of the total offshore load and the total offshore energy storage, the surplus electric energy is sent to the onshore power grid or other offshore virtual power plants. The specific judgment formula is as follows:

[0054]

[0055] When the sum of the total generated electric energy of the offshore power unit and the total offshore energy storage is less than the total offshore load, the onshore power grid or other offshore virtual power plants supply supplementary power. The specific judgment formula is as follows:

[0056]

[0057] When the total generated electric energy of the offshore power unit is greater than or equal to the total offshore load and less than or equal to the sum of the total offshore load and the total offshore energy storage, the offshore virtual power plant is in a self-balanced state and does not need to supply power to each other with the onshore power grid or other offshore virtual power plants. The specific judgment formula is as follows:

[0058]

[0059] The present invention has the following beneficial effects:

[0060] 1. The offshore virtual power plant proposed by the present invention constructs the offshore power source and the offshore energy storage into a whole, realizes the adjustable and controllable output of the offshore new energy through the offshore energy storage, improves the operation reliability of the offshore power system through interconnection, and realizes the optimal scheduling and stable operation of each offshore unit through the intelligent control system.

[0061] 2. The AC / DC power supply system of the offshore virtual power plant in the present invention can meet the power consumption needs of offshore loads such as offshore oil and gas exploitation, offshore farms, seawater hydrogen production, and charging of various types of ships nearby with the electric energy generated by offshore power sources, avoiding long-distance transmission and detour losses of electric energy, reducing long-distance cable investment and power losses, improving the utilization efficiency of offshore resources, enhancing the offshore endurance of offshore vehicles such as ships, saving the configuration and investment of AC / DC conversion charging equipment for ships, and improving the convenience of offshore charging nearby.

[0062] 3. The AC / DC power supply system and method of the offshore virtual power plant in the present invention comprehensively consider the electric energy provided by offshore power sources and offshore energy storage, the power consumption needs and priorities of offshore loads, and formulate an optimal power distribution plan, which can not only meet the power consumption of offshore loads with different priorities, but also provide DC power supply with different voltage levels and AC power supply with different voltages and frequencies for different types of offshore loads respectively.

[0063] 4. The AC / DC power supply system of the offshore virtual power plant in the present invention can also increase the connection unit with the onshore power grid or other offshore virtual power plants, expand the scope of power sources, grids, loads, and energy storage, and realize the optimized distribution and utilization of offshore electric energy in a larger range. BRIEF DESCRIPTION OF THE DRAWINGS

[0064] Figure 1 It is a schematic diagram of the connection between each unit of the present invention;

[0065] Figure 2 It is a schematic diagram of the connection between each unit in the simulation project. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0066] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0067] It should be understood that the step numbers used in the text are only for convenient description and do not limit the execution order of the steps.

[0068] It should be understood that the terms used in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. As used in the specification of the present invention and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an", and "the" are intended to include the plural forms.

[0069] The terms "comprising" and "including" indicate the presence of the described features, wholes, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, wholes, steps, operations, elements, components, and / or their combinations.

[0070] The term "and / or" refers to any combination and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0071] Example 1:

[0072] See Figure 1 , a marine virtual power plant AC / DC power supply system, characterized in that it includes:

[0073] A marine power supply unit that converts marine renewable energy into electrical energy based on various marine power generation stations; the various marine power generation stations include marine wind power, marine photovoltaic, and wave energy marine power generation stations;

[0074] In this embodiment, in addition to marine wind power, marine photovoltaic, and wave energy marine power generation stations, it also includes a series of marine power generation stations that can convert marine renewable energy into electrical energy, such as tidal energy power generation stations, ocean thermal energy conversion power generation stations, salinity gradient energy power generation stations, ocean current energy power generation stations, marine biomass energy power generation stations, floating nuclear power plants, etc.

[0075] A marine energy storage unit that stores the electrical energy generated by the power supply unit based on various marine energy storage stations; the various marine energy storage stations include island pumped storage, electrochemical energy storage, and underwater compressed air marine energy storage stations;

[0076] In this embodiment, in addition to the island pumped storage, electrochemical energy storage, and underwater compressed air marine energy storage stations, it also includes a series of marine energy storage stations that can store the electrical energy generated by the power supply unit, such as marine gravity energy storage, marine flywheel energy storage, marine hydrogen energy storage, marine salinity gradient energy storage, marine thermal energy storage, floating energy storage platforms, etc.

[0077] A marine AC / DC power supply unit that uses AC / DC power supply equipment to meet the power consumption needs of various types of marine loads;

[0078] In this embodiment, the AC / DC power supply equipment includes low-voltage DC power supply equipment (such as 110V), medium-voltage DC power supply equipment (such as 220V), low-voltage industrial frequency AC power supply equipment (such as 380V, 50Hz), medium-voltage industrial frequency AC power supply equipment (such as 110V, 50Hz), medium-voltage non-industrial frequency AC power supply equipment (such as 110V, 60Hz), other voltage and frequency AC power supply equipment, etc.

[0079] The offshore power supply ranking unit ranks the power supply priorities of various types of offshore loads based on the supply-demand relationship among the offshore power supply unit, the offshore energy storage unit, and various types of offshore loads.

[0080] The sea-land interconnected power supply unit balances the power consumption demands of the power grids in both the sea and land areas based on the power consumption demands of various types of offshore loads and the power supply capabilities of the offshore power supply unit.

[0081] The intelligent control unit includes a data acquisition and monitoring module, an energy management module, a safety protection module, and an information transmission and communication module; it is used to coordinate the optimal operation modes of the offshore power supply unit, the offshore energy storage unit, and the offshore AC / DC power supply unit, and achieve the optimal scheduling among the units.

[0082] In this embodiment, it consists of units such as the offshore power supply, offshore energy storage, offshore AC / DC power supply, offshore power supply ranking, sea-land interconnected power supply, and intelligent control. The intelligent control unit aggregates the offshore power supply unit and the offshore energy storage unit and constructs them into a whole, and supplies power to external offshore loads through the offshore AC / DC power supply unit.

[0083] The connection situation among the units is as Figure 1 shown.

[0084] As a preferred implementation mode of this embodiment, the AC / DC power supply equipment includes DC power supply equipment, industrial frequency AC power supply equipment, and non-industrial frequency AC power supply equipment, and realizes generalization and standardization with the charging equipment interfaces of various types of offshore loads.

[0085] In this embodiment, the industrial frequency of the AC power is 50Hz. In addition to the above-mentioned AC / DC power supply equipment, the equipment that can be used also includes high-voltage AC power supply equipment, ultra-high-voltage AC power supply equipment, non-industrial frequency AC power supply equipment, and variable-frequency AC power supply equipment.

[0086] As a preferred implementation mode of this embodiment, the various types of offshore loads include offshore oil and gas exploitation, ocean ranching, seawater hydrogen production, and charging of various types of ships. Among them, the charging of various types of ships has the highest power supply priority.

[0087] In this embodiment, in addition to the above-mentioned offshore oil and gas exploitation, ocean ranching, seawater hydrogen production, and charging of various types of ships, the various types of offshore loads also include loads in multiple aspects such as deep-sea mining equipment, deep-sea scientific research stations and unmanned submersibles, ocean meteorological and seismic monitoring networks, cruise ships and offshore resorts.

[0088] As a preferred implementation mode of this embodiment, the steps of ranking the power supply priorities of various types of offshore loads based on the supply-demand relationship among the offshore power supply unit, the offshore energy storage unit, and various types of offshore loads are specifically as follows:

[0089] When the total generated electrical energy of the offshore power unit is greater than the electricity demand of various types of offshore loads, the offshore virtual power plant first supplies all offshore loads, and then stores the surplus electrical energy in the offshore energy storage unit. The specific calculation formula is as follows:

[0090]

[0091] In the formula, F is the power generation of the offshore power source, i is the serial number of the offshore power source, and m is the total number of offshore power sources; L is the electricity consumption of various types of offshore loads, k is the serial number of various types of offshore loads, and s is the number of various types of offshore loads;

[0092] When the total generated electrical energy of the offshore power unit is less than the electricity demand of various types of offshore loads and greater than or equal to the electricity demand of the ship load, the offshore virtual power plant preferentially supplies the ship load, and the remaining generated electrical energy and energy storage electrical energy jointly supply other offshore loads. The specific calculation formula is as follows:

[0093]

[0094] In the formula, B(h) is the electricity consumption of the ship load, h is the ship serial number, and t is the number of ships;

[0095] When the total generated electrical energy of the offshore power unit is less than the electricity demand of the ship load, the offshore virtual power plant preferentially supplies the electricity demand of the ship load with the total generated electrical energy and the energy storage electrical energy; if there is an electrical energy surplus, it also supplies part of the other offshore loads at the same time, in accordance with the priority order of the remaining various offshore loads; if the electrical energy is still insufficient, it is charged sequentially according to the time sequence of the ships arriving at the offshore virtual power plant. The specific calculation formula is as follows:

[0096]

[0097] As a preferred implementation manner of this embodiment, the step of balancing the electricity demands of the land and sea power grids based on the electricity demands of various types of offshore loads and the power supply capacity of the offshore power unit is specifically as follows:

[0098] When the total generated electrical energy of the offshore power unit is greater than the sum of the total offshore load and the total offshore energy storage, the surplus electrical energy is sent to the land power grid or other offshore virtual power plants. The specific judgment formula is as follows:

[0099]

[0100] When the sum of the total generated electrical energy of the offshore power unit and the total offshore energy storage is less than the total offshore load, the land power grid or other offshore virtual power plants supply supplementary power. The specific judgment formula is as follows:

[0101]

[0102] When the total generated electric energy of the offshore power unit is greater than or equal to the total offshore load and less than or equal to the sum of the total offshore load and the total offshore energy storage, the offshore virtual power plant is in a self-balanced state and does not need to supply power to each other with the onshore power grid or other offshore virtual power plants. The specific judgment formula is as follows:

[0103]

[0104] Embodiment 2:

[0105] An AC-DC power supply method for an offshore virtual power plant, the specific steps include:

[0106] Converting offshore renewable energy into electric energy based on various offshore power generation power stations; the various offshore power generation power stations include offshore wind power, offshore photovoltaic, and wave energy offshore power generation power stations;

[0107] Storing the electric energy generated by the power supply unit based on various offshore energy storage power stations; the various offshore energy storage power stations include island pumped storage, electrochemical energy storage, and underwater compressed air offshore energy storage power stations;

[0108] Using AC-DC power supply equipment to meet the electricity consumption needs of various types of offshore loads;

[0109] Based on the supply-demand relationship between the offshore power supply unit, the offshore energy storage unit, and various types of offshore loads, sorting the power supply priorities for various types of offshore loads;

[0110] Based on the electricity consumption needs of various types of offshore loads and the power supply capacity of the offshore power supply unit, balancing the electricity consumption needs of the onshore and offshore power grids;

[0111] Constructing an intelligent control unit, including a data acquisition and monitoring module, an energy management module, a safety protection module, and an information transmission and communication module; used to coordinate the optimal operation modes of the offshore power supply unit, the offshore energy storage unit, and the offshore AC-DC power supply unit, and achieve the optimal scheduling among the units.

[0112] As a preferred implementation manner of this embodiment, the AC-DC power supply equipment includes DC power supply equipment, industrial frequency AC power supply equipment, and non-industrial frequency AC power supply equipment, and realizes generalization and standardization with the charging equipment interfaces of various types of offshore loads.

[0113] As a preferred implementation manner of this embodiment, the various types of offshore loads include offshore oil and gas exploitation, offshore ranching, seawater hydrogen production, and charging of various types of ships. Among them, the charging of various types of ships has the highest power supply priority.

[0114] As a preferred implementation manner of this embodiment, the step of sorting the power supply priorities for various types of offshore loads based on the supply-demand relationship between the offshore power supply unit, the offshore energy storage unit, and various types of offshore loads is specifically as follows:

[0115] When the total generated electric energy of the offshore power unit is greater than the electricity demand of various types of offshore loads, the offshore virtual power plant first supplies all offshore loads, and then stores the surplus electric energy in the offshore energy storage unit. The specific calculation formula is as follows:

[0116]

[0117] In the formula, F is the power generation of the offshore power source, i is the serial number of the offshore power source, and m is the total number of offshore power sources; L is the electricity consumption of various types of offshore loads, k is the serial number of various types of offshore loads, and s is the number of various types of offshore loads;

[0118] When the total generated electric energy of the offshore power unit is less than the electricity demand of various types of offshore loads and greater than or equal to the electricity demand of the ship load, the offshore virtual power plant preferentially supplies the ship load, and the remaining generated electric energy and stored energy are jointly used to supply other offshore loads. The specific calculation formula is as follows:

[0119]

[0120] In the formula, B(h) is the electricity consumption of the ship load, h is the ship serial number, and t is the number of ships;

[0121] When the total generated electric energy of the offshore power unit is less than the electricity demand of the ship load, the offshore virtual power plant preferentially supplies the electricity demand of the ship load with the total generated electric energy and stored energy; if there is surplus electric energy, it also supplies part of other offshore loads at the same time, in accordance with the priority order of the remaining various offshore loads; if the electric energy is still insufficient, it is charged sequentially according to the time sequence of the ships arriving at the offshore virtual power plant. The specific calculation formula is as follows:

[0122]

[0123] As a preferred implementation manner of this embodiment, the steps of balancing the electricity demands of the land and sea power grids based on the electricity demands of various types of offshore loads and the power supply capacity of the offshore power unit are specifically as follows:

[0124] When the total generated electric energy of the offshore power unit is greater than the sum of the total offshore load and the total offshore energy storage, the surplus electric energy is sent to the land power grid or other offshore virtual power plants. The specific judgment formula is as follows:

[0125]

[0126] When the sum of the total generated electric energy of the offshore power unit and the total offshore energy storage is less than the total offshore load, the land power grid or other offshore virtual power plants supply supplementary power. The specific judgment formula is as follows:

[0127]

[0128] When the total generated electrical energy of the offshore power unit is greater than or equal to the total offshore load and less than or equal to the sum of the total offshore load and the total offshore energy storage, the offshore virtual power plant is in a self-balanced state and does not need to supply power to each other with the onshore power grid or other offshore virtual power plants. The specific judgment formula is as follows:

[0129]

[0130] Embodiment 3:

[0131] Based on the method systems of the above-mentioned Embodiment 1 and Embodiment 2, a simulation test is carried out. The specific steps are as follows:

[0132] Select an area along the eastern coast near offshore oil and gas exploitation and with an island distributed, and carry out a demonstration of three-dimensional composite utilization.

[0133] The offshore power sources of this demonstration project include 1 offshore wind power, 1 offshore photovoltaic power, and 1 wave energy power station; the offshore energy storage includes 1 island pumped storage, 1 underwater compressed air energy storage, and 1 electrochemical energy storage power station; the offshore loads include 1 offshore oil and gas exploitation platform, 1 ocean ranch, 1 seawater hydrogen production plant, and several electrified ships.

[0134] The connection situation between each unit is as Figure 2 shown. Among them, the offshore power supply sorting unit and the onshore-offshore networking power supply unit are set in the intelligent control unit and are not marked in the figure. The specific connection method is as follows:

[0135] (1) All offshore power units are connected to the DC busbar of the offshore booster station; (2) All offshore energy storage units are connected to the DC busbar of the offshore booster station, so as to construct the offshore power source and the offshore energy storage into a whole; (3) An AC-DC power supply unit connected to the DC busbar is built in the offshore booster station, including low-voltage DC power supply equipment (such as 110V), medium-voltage DC power supply equipment (such as 220V), low-voltage industrial frequency AC power supply equipment (such as 380V, 50Hz), medium-voltage industrial frequency AC power supply equipment (such as 110V, 50Hz), medium-voltage non-industrial frequency AC power supply equipment (such as 110V, 60Hz), and other AC power supply equipment with different voltages and frequencies; (4) An intelligent control unit is configured in the booster station, which is connected to the DC busbar and its interfaces with the power generation unit, the energy storage unit, and the AC-DC power consumption unit.

[0136] The above are only the embodiments of the present invention, and do not limit the patent scope of the present invention accordingly. Any equivalent structural or equivalent process transformation made by using the content of the specification and drawings of the present invention, or directly or indirectly applied in other related technical fields, shall be included in the patent protection scope of the present invention by the same token.

Claims

1. An AC / DC power supply system for an offshore virtual power plant, characterized in that: include: Offshore power units, which convert offshore renewable energy into electrical energy based on various offshore power plants; The various types of offshore power plants include offshore wind power, offshore photovoltaic and wave energy offshore power plants; Offshore energy storage units store the electrical energy generated by power supply units based on various offshore energy storage power stations; the various offshore energy storage power stations include island pumped storage, electrochemical energy storage and underwater compressed air offshore energy storage power stations; Offshore AC / DC power supply units use AC / DC power supply equipment to meet the power demand of various types of loads at sea; The offshore power supply sorting unit sorts the power supply priorities of various types of offshore loads based on the supply and demand relationship between the offshore power supply unit, the offshore energy storage unit and various types of offshore loads; The sea-land interconnected power supply unit balances the power demand of the sea and land power grids based on the power demand of various types of loads at sea and the power supply capacity of the offshore power supply unit; The intelligent control unit includes a data acquisition and monitoring module, an energy management module, a safety protection module and an information transmission and communication module; it is used to coordinate the optimal operation mode of the offshore power supply unit, the offshore energy storage unit and the offshore AC / DC power supply unit to achieve optimal scheduling among the units.

2. The AC / DC power supply system of an offshore virtual power plant according to claim 1, characterized in that: The AC / DC power supply equipment includes DC power supply equipment, industrial frequency AC power supply equipment and non-industrial frequency AC power supply equipment, and realizes universalization and standardization with charging equipment interfaces of various types of offshore loads.

3. The AC / DC power supply system of an offshore virtual power plant according to claim 1, characterized in that: The various types of offshore loads include offshore oil and gas exploitation, marine ranching, seawater hydrogen production and charging of various types of ships, among which the power supply priority for charging of various types of ships is the highest.

4. The AC / DC power supply system of an offshore virtual power plant according to claim 3, characterized in that: The steps of prioritizing the power supply of various types of offshore loads based on the supply and demand relationship between the offshore power supply unit, the offshore energy storage unit and various types of offshore loads are specifically as follows: When the total power generated by the offshore power unit is greater than the power demand of various types of loads at sea, the offshore virtual power plant first supplies power to all offshore loads, and then stores the surplus power in the offshore energy storage unit. The specific calculation formula is as follows: In the formula, F is the power generation of the offshore power source, i is the serial number of the offshore power source, and m is the total number of offshore power sources; L is the power consumption of various types of offshore loads, k is the serial number of various types of offshore loads, and s is the number of various types of offshore loads; When the total power generated by the offshore power unit is less than the power demand of various types of loads at sea, and is greater than or equal to the power demand of ship loads, the offshore virtual power plant will give priority to supplying ship loads, and the remaining power generated and stored power will jointly supply other offshore loads. The specific calculation formula is as follows: In the formula, B(h) is the power consumption of the ship load, h is the ship serial number, and t is the number of ships; When the total power generated by the offshore power unit is less than the power demand of the ship load, the offshore virtual power plant will give priority to the total power generation and energy storage power to jointly supply the power demand of the ship load; if there is a surplus of power, it will also supply some other offshore loads in accordance with the priority order of the other various offshore loads; if the power is still insufficient, it will be charged in sequence according to the time sequence of the ship arriving at the offshore virtual power plant. The specific calculation formula is as follows:

5. An AC / DC power supply system for an offshore virtual power plant according to claim 4, characterized in that: The steps of balancing the power demand of the sea and land power grids based on the power demand of various types of loads at sea and the power supply capacity of the sea power unit are specifically as follows: When the total power generated by the offshore power unit is greater than the sum of the total offshore load and the total offshore energy storage, the surplus power is sent to the land power grid or other offshore virtual power plants. The specific judgment formula is as follows: When the sum of the total power generated by the offshore power unit and the total offshore energy storage is less than the total offshore load, the land power grid or other offshore virtual power plants will provide additional power. The specific judgment formula is as follows: When the total power generated by the offshore power unit is greater than or equal to the total offshore load, and less than or equal to the sum of the total offshore load and the total offshore energy storage, the offshore virtual power plant is in a self-balancing state and does not need to be supplied to the land power grid or other offshore virtual power plants. The specific judgment formula is as follows:

6. An AC / DC power supply method for an offshore virtual power plant, characterized in that: The specific steps include: Converting offshore renewable energy into electrical energy based on various offshore power plants; the various offshore power plants include offshore wind power, offshore photovoltaic and wave power plants; The electric energy generated by the power supply unit is stored based on various offshore energy storage power stations; the various offshore energy storage power stations include island pumped storage, electrochemical energy storage and underwater compressed air offshore energy storage power stations; Use AC and DC power supply equipment to meet the power demand of various types of loads at sea; Based on the supply and demand relationship between offshore power units, offshore energy storage units and various types of offshore loads, the power supply priority of various types of offshore loads is sorted; Based on the power demand of various types of loads at sea and the power supply capacity of offshore power units, balance the power demand of the sea and land power grids; Build an intelligent control unit, including a data acquisition and monitoring module, an energy management module, a safety protection module, and an information transmission and communication module; it is used to coordinate the optimal operation mode of the offshore power supply unit, the offshore energy storage unit, and the offshore AC / DC power supply unit to achieve optimal scheduling among the units.

7. The AC / DC power supply method for an offshore virtual power plant according to claim 6, characterized in that: The AC / DC power supply equipment includes DC power supply equipment, industrial frequency AC power supply equipment and non-industrial frequency AC power supply equipment, and realizes universalization and standardization with charging equipment interfaces of various types of offshore loads.

8. The AC / DC power supply method for an offshore virtual power plant according to claim 6, characterized in that: The various types of offshore loads include offshore oil and gas exploitation, marine ranching, seawater hydrogen production and charging of various types of ships, among which the power supply priority for charging of various types of ships is the highest.

9. The AC / DC power supply method for an offshore virtual power plant according to claim 8, characterized in that: The steps of prioritizing the power supply of various types of offshore loads based on the supply and demand relationship between the offshore power supply unit, the offshore energy storage unit and various types of offshore loads are specifically as follows: When the total power generated by the offshore power unit is greater than the power demand of various types of loads at sea, the offshore virtual power plant first supplies power to all offshore loads, and then stores the surplus power in the offshore energy storage unit. The specific calculation formula is as follows: In the formula, F is the power generation of the offshore power source, i is the serial number of the offshore power source, and m is the total number of offshore power sources; L is the power consumption of various types of offshore loads, k is the serial number of various types of offshore loads, and s is the number of various types of offshore loads; When the total power generated by the offshore power unit is less than the power demand of various types of loads at sea, and is greater than or equal to the power demand of ship loads, the offshore virtual power plant will give priority to supplying ship loads, and the remaining power generated and stored power will jointly supply other offshore loads. The specific calculation formula is as follows: In the formula, B(h) is the power consumption of the ship load, h is the ship serial number, and t is the number of ships; When the total power generated by the offshore power unit is less than the power demand of the ship load, the offshore virtual power plant will give priority to the total power generation and energy storage power to jointly supply the power demand of the ship load; if there is a surplus of power, it will also supply some other offshore loads in accordance with the priority order of the other various offshore loads; if the power is still insufficient, it will be charged in sequence according to the time sequence of the ship arriving at the offshore virtual power plant. The specific calculation formula is as follows:

10. The AC / DC power supply method for an offshore virtual power plant according to claim 9, characterized in that: The steps of balancing the power demand of the sea and land power grids based on the power demand of various types of loads at sea and the power supply capacity of the sea power unit are specifically as follows: When the total power generated by the offshore power unit is greater than the sum of the total offshore load and the total offshore energy storage, the surplus power is sent to the land power grid or other offshore virtual power plants. The specific judgment formula is as follows: When the sum of the total power generated by the offshore power unit and the total offshore energy storage is less than the total offshore load, the land power grid or other offshore virtual power plants will provide additional power. The specific judgment formula is as follows: When the total power generated by the offshore power unit is greater than or equal to the total offshore load, and less than or equal to the sum of the total offshore load and the total offshore energy storage, the offshore virtual power plant is in a self-balancing state and does not need to be supplied to the land power grid or other offshore virtual power plants. The specific judgment formula is as follows:

Images