A green pumped hydro energy storage, phase modulation and power generation system offshore

Abstract

The application provides a green offshore pumped storage energy, phase modulation and power generation system, which comprises a wind turbine or a wind turbine group, an offshore water tower, a water turbine, an excitation or permanent magnet synchronous generator and a water pumping pump, the excitation or permanent magnet synchronous generator is located in the offshore water tower, the wind turbine or the wind turbine group is located at the top of the offshore water tower or is distributed around the offshore water tower, the vertical excitation or permanent magnet synchronous generator is coaxially connected with the water turbine, a lower water outlet with a volute is arranged in the offshore water tower, a water storage tank is arranged above the offshore water tower, a tower water chamber, a tower water outlet channel, a sea outlet, a water inlet and corresponding valves and related circuit structures are arranged below the offshore water tower. The system can realize a novel offshore energy utilization, integrates offshore pumped storage energy, offshore power generation and offshore phase modulation into a unified structure, takes into account the operation state of the land power grid, fully utilizes offshore resources and improves the utilization rate of wind power generation.

Description

Technical Field

[0001] This invention relates to the field of offshore wind power generation technology, and in particular to an offshore green pumped storage, phase regulation and power generation system. Background Technology

[0002] Wind power is the world's fastest-growing green energy technology. While onshore wind farms are developing rapidly, people have noticed some limitations to onshore wind energy utilization, such as large land area requirements and noise pollution. Due to the abundant offshore wind energy resources and the feasibility of current technologies, the ocean is poised to become a rapidly developing wind power market.

[0003] Currently, existing offshore green power generation methods are not easily connected to the land-based power grid. Furthermore, when generating wind power at sea, the natural wind is uncontrollable, leading to energy loss and waste of excess offshore power. Summary of the Invention

[0004] The embodiments of the present invention provide a green offshore pumped storage, phase regulation and power generation system to improve the utilization rate of offshore wind power generation.

[0005] To achieve the above objectives, the present invention adopts the following technical solution.

[0006] A green offshore pumped-storage, phase-regulating, and power generation system includes: a wind turbine or wind turbine cluster, an offshore water tower, a turbine, an excitation or permanent magnet synchronous generator, and a pump. The excitation or permanent magnet synchronous generator is located inside the offshore water tower. The wind turbine or wind turbine cluster is located at the top of the offshore water tower or distributed around the offshore water tower. The vertical excitation or permanent magnet synchronous generator is coaxially connected to the turbine. A drainage outlet with a spiral casing is provided inside the offshore water tower. A water storage tank is provided above the offshore water tower. An internal water chamber, an internal drainage channel, a discharge outlet, a water inlet, and corresponding valves and related circuit structures are provided below the offshore water tower.

[0007] Preferably, the offshore water tower is constructed of reinforced concrete. A water storage tank is installed above the offshore water tower. The water storage tank is connected to a spiral casing below the water storage tank via a valve below the water storage tank. A water flow channel located below the spiral casing is installed inside the spiral casing and is connected to the blades of the water turbine generator. The water flow drives a vertically placed excitation or permanent magnet synchronous generator through the spiral casing.

[0008] Preferably, the excitation or permanent magnet synchronous generator is fixed to the tower body by a support frame. An internal water chamber is provided below the offshore water tower. The internal water chamber is connected to the seawater outside the tower through a water inlet and corresponding valves. A water pump is installed in the internal water chamber. The seawater pumped out by the water pump is discharged into the sea through a drainage channel and a discharge outlet and corresponding valves, or discharged into a water storage tank above the water tower through a drainage channel.

[0009] Preferably, the system is equipped with switches K1, K2 and K3. Switch K1 is connected to the offshore wind turbine, switch K2 is connected to the power grid inside the water tower, and switch K3 is connected to the land power grid. The functions of offshore green pumped water storage, phase adjustment and power generation are realized by controlling the switch elements K1, K2 and K3. The offshore wind turbine is equipped with a wind turbine, a generator and a controller.

[0010] Preferably, when there is a power surplus in the power grid, if the source of the power surplus is determined to be the wind turbine generator, the control switch K1 in the corresponding control circuit is closed. If the source of the power surplus is determined to be the land power grid, the control switch K3 in the corresponding control circuit is closed, so that the system can detect the power surplus on the source side and put the system into the pumped water storage state. The control switch K2 is closed to open the water inlet at the bottom of the tower, allowing seawater to flow into the water chamber inside the tower. The system checks whether the water pump inside the tower can work normally and whether it is necessary to run the permanent magnet or excitation turbine generator to the standby water pump state to participate in the pumped water storage. The seawater is pumped to the water storage tank at the top of the tower through the drainage channel ② by controlling the valve.

[0011] Preferably, when there is a power shortage in the power grid, the system is put into power generation mode, and the power shortage is made up by one or more of the following three power generation methods according to the actual power generation surplus of the power generation device:

[0012] Power generation method 1: Increase power generation by controlling the terrestrial power grid;

[0013] Power generation method 2: Close control switches K1 and K3 to increase power generation by adjusting the offshore wind turbine.

[0014] Power generation method three: Close control switches K2 and K3 to send the generated electricity into the power grid, use the water stored in the water tower to generate electricity, open the water inlet or outlet to let seawater flow out of the tower, open the valve of the water storage tank, and let the water at the top of the tower pass through the spiral casing and impact the water turbine to generate electricity.

[0015] Preferably, when the reactive power of the power grid is unbalanced, the system is placed in the phase adjustment state, the permanent magnet or excitation synchronous generator is operated to the synchronous condenser state, the synchronous condenser is in the motor state of no-load or low-load operation, the water inlet is closed, the outlet is opened, the indoor water is emptied by the water pump, and then the control switches K2 and K3 are closed to integrate the reactive power generated by the synchronous condenser into the power grid. The reactive power of the power grid is balanced through real-time adjustment.

[0016] Preferably, one or a group of wind turbines are installed in the independent offshore green pumped storage, phase regulation and power generation system. The wind turbines are integrated with the water tower and located at the top of the tower, with no other wind turbines around them.

[0017] In the distributed offshore green pumped storage, phase regulation and power generation system, the top of the water tower is not equipped with a wind turbine, but the wind turbine group is distributed around the water tower to form a wind turbine network and is connected to the water tower.

[0018] One or more wind turbines are installed on top of the water tower of a centralized offshore green pumped storage, phase regulation and power generation system. The wind turbines and the water tower are integrated. A group of wind turbines is also installed around the water tower, which is connected to the water tower and together provides power to the system.

[0019] Preferably, the independent offshore green pumped storage, phase regulation and power generation system includes a green pumped storage reservoir, drainage channels, pumps in the water chamber inside the tower, an excitation or permanent magnet synchronous generator that can be changed to a standby pump, a sea inlet, and related circuit structures. When there is excess power from offshore wind turbines or the onshore power grid, the system stores excess power through green pumping. When the pumps in the water chamber inside the tower fail or the pumping volume is insufficient, the excitation or permanent magnet synchronous generator is changed to a synchronous motor and used as a standby pump. The inlet with a valve is open, seawater from outside the tower flows into the water chamber inside the tower, the pumps start working, and the seawater is sent to the reservoir at the top of the tower through the drainage pipe.

[0020] Preferably, the electrical energy generated by the wind turbine or wind turbine group is connected to the terrestrial power grid after passing through a frequency regulator, realizing the grid connection of wind power generation; when the wind turbine or wind turbine group needs to be shut down, it generates electricity through an excitation or permanent magnet synchronous generator and connects to the terrestrial power grid.

[0021] The frequency regulator of the wind turbine is located inside the wind turbine or in the offshore water tower. Switch K1, which is connected to the offshore wind turbine, and switch K3, which is connected to the land power grid, are closed. Switch K2, which is connected to the power network inside the water tower, is open. The valve under the water tank is opened. The water above the water tank flows out of the drain outlet through the spiral casing channel and impacts the turbine blades. The blades rotate and drive the excitation or permanent magnet synchronous generator to generate electricity. The water flowing out of the turbine blades will flow into the water chamber inside the tower. The inlet or outlet is open to discharge excess seawater outside the tower.

[0022] As can be seen from the technical solutions provided by the embodiments of the present invention above, the present invention provides a marine green pumped storage, phase regulation and power generation system. This system can realize a new type of marine energy utilization. It integrates marine pumped storage, marine power generation and marine phase regulation into a unified structure, takes into account the operation status of the land power grid, makes full use of marine resources and improves the utilization rate of wind power generation.

[0023] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and will become apparent from the description or may be learned by practice of the invention. Attached Figure Description

[0024] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 , Figure 2 , Figure 3 and Figure 4 This is a schematic diagram of a stand-alone offshore green pumped-storage, phase-regulation, and power generation system provided in an embodiment of the present invention; the components in the diagram are as follows:

[0026] 1 is the water storage tank above the water tower.

[0027] 2 is the valve below the water storage tank.

[0028] 3 is the spiral shell below the reservoir.

[0029] 4 is the drainage channel under the volute.

[0030] 5 refers to a vertical coaxial turbine and an excitation or permanent magnet synchronous generator.

[0031] 6 is the turbine fan blade.

[0032] 7 is the cross-shaped support frame used to fix the water turbine and synchronous generator.

[0033] 8 is the water pump for the water chamber inside the tower.

[0034] 9 is the water chamber inside the tower.

[0035] 10 is a single wind turbine located at the top of the tower.

[0036] 11 is a group of wind turbines located at the top of the tower.

[0037] 12 is a group of wind turbines located outside the tower.

[0038] 13 refers to the wind turbine grid located at the top of the tower and outside the tower. 14 refers to the power transmission lines of the wind turbine (such as submarine cables).

[0039] 15 is the wind turbine blade.

[0040] 16 is drainage channel ②, which can drain water to the reservoir.

[0041] 17 is drainage channel ①, which drains water to the sea via the outlet. 18 is a backup water pump channel, which drains water to channels ① and ②.

[0042] 19 is the water channel for the pump inside the water chamber of the tower, which can drain water to channel ①. ②20 is the outlet (with valve) of the water chamber inside the tower.

[0043] 21 is the water inlet (with valve).

[0044] 22 is connected to the A, B, and C phases of the wind turbine.

[0045] 23 is connected to the A, B, and C phases of the terrestrial power grid.

[0046] 24 is the switch K1 connected to the offshore wind turbine.

[0047] 25 is the connection between switch K2 and the electrical network inside the water tower.

[0048] 26 is the switch K3 connected to the terrestrial power grid.

[0049] 27 is the seawater in the tower's water chamber.

[0050] 28 is the seawater outside the tower.

[0051] 29 is the roof of the offshore water tower (optional).

[0052] 30 refers to the wind turbine tower.

[0053] Figure 5 This is a complex control logic block diagram based on switching elements for an embodiment of the present invention of a marine green pumped storage, phase regulation and power generation system. Detailed Implementation

[0054] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein 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 accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0055] Those skilled in the art will understand that, unless specifically stated otherwise, the singular forms “a,” “an,” “the,” and “the” used herein may also include the plural forms. It should be further understood that the term “comprising” as used in this specification means the presence of the stated features, integers, steps, operations, elements, and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. It should be understood that when we say an element is “connected” or “coupled” to another element, it can be directly connected or coupled to the other element, or there may be intermediate elements. Furthermore, “connected” or “coupled” as used herein can include wireless connections or couplings. The term “and / or” as used herein includes any and all combinations of one or more of the associated listed items.

[0056] It will be understood by those skilled in the art that, unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. It should also be understood that terms such as those defined in general dictionaries should be understood to have the same meaning as in the context of the prior art, and should not be interpreted in an idealized or overly formal sense unless defined as herein.

[0057] To facilitate understanding of the embodiments of the present invention, the following will provide further explanation and description with reference to the accompanying drawings and several specific embodiments. These embodiments do not constitute a limitation on the embodiments of the present invention.

[0058] The structure of a marine green pumped-storage, phase-regulation, and power generation system provided in this embodiment of the invention is as follows: Figure 1 , Figure 2 , Figure 3 and Figure 4 As shown. The system includes a wind turbine or wind turbine group, an offshore water tower, a water turbine, an excitation or permanent magnet synchronous generator, and a water pump. The offshore water tower is equipped with a bottom drain outlet with a spiral casing. A water storage tank is set on top of the water tower. The bottom of the water tower is equipped with an internal water chamber, an internal drainage channel, a discharge outlet, a water inlet, and corresponding valves and related circuit structures.

[0059] The offshore water tower is constructed of reinforced concrete. A water storage tank 1 sits atop the tower. The water storage tank 1 is connected to a spiral casing 3 below the tank via a valve 2. The valve 2 can also be placed at the end of the spiral casing 3. Inside the spiral casing 3, a water flow channel 4, located below the casing and connected to the turbine generator blades, drives an excitation or permanent magnet synchronous generator 5. The excitation or permanent magnet synchronous generator 5 is coaxially connected to the turbine and is vertically positioned. The excitation or permanent magnet synchronous generator 5 can be converted to operate as a synchronous motor, or, when needed, can be used as a synchronous condenser or a pump with backup pumping capabilities. The vertical excitation or permanent magnet synchronous generator 5 is located inside the water tower and is fixed to the tower body by a cross-shaped support frame 7 made of steel or other materials. The cross-shaped support frame 7 can also be of other shapes. At the bottom of the offshore water tower, there is an internal water chamber 9, which is connected to the seawater outside the tower via an inlet and corresponding valves. A backup water pump 8 is installed in the water chamber 9 inside the tower. The water pump 8 can replace the excitation or permanent magnet synchronous generator 5 mentioned above. The seawater pumped by the water pump 8 can be discharged into the sea through the drainage channel ①17 and the corresponding valve; or it can be discharged into the water storage tank above the water tower through the drainage channel ②16.

[0060] The system includes key circuit structures: switch K1 (24) is connected to the offshore wind turbine, switch K2 (25) is connected to the power grid inside the water tower, and switch K3 (26) is connected to the land power grid. By controlling the switching elements K1, K2, and K3, the functions of offshore green pumped-storage, phase regulation, and power generation are achieved. The offshore wind turbine contains a wind turbine, a generator, and a controller. The matching frequency regulator can be integrated inside the wind turbine or placed in the water tower structure. Furthermore, depending on the configuration of the offshore wind turbine, three main expansion structures are provided: independent, distributed, and centralized offshore green pumped-storage, phase regulation, and power generation systems.

[0061] In a stand-alone offshore green pumped-storage, phasing, and power generation system, one or more wind turbines are installed, integrated with the water tower and located at the top of the tower, with no other wind turbines surrounding it. In a distributed offshore green pumped-storage, phasing, and power generation system, no wind turbines are installed at the top of the water tower; instead, a group of wind turbines is distributed around the water tower, forming a wind turbine network connected to the water tower. A centralized offshore green pumped-storage, phasing, and power generation system combines the above two structures: one or more wind turbines are installed at the top of the water tower, integrated with the water tower, and a group of wind turbines is also installed around the water tower, connected to the water tower, collectively providing power to the system. Finally, considering the uncertainty of offshore wind power generation, the above three structures can be configured individually or in combination to optimize the offshore resource utilization structure and realize the functions of offshore pumped-storage, offshore power generation, and offshore phasing.

[0062] The present invention provides a complex control logic block diagram based on switching elements for a marine green pumped storage, phase regulation, and power generation system, as shown in the embodiment of the invention. Figure 5 As shown, this system is used to achieve refined offshore green pumped-storage, power generation, and phase regulation functions. Switching elements such as K1, K2, and K3, along with other control units, can be integrated into a specific control room within the water tower. Figure 5 The control process is presented under the conditions of power grid excess, power shortage and reactive power imbalance. Based on the changes in the power grid system, refined countermeasures are taken.

[0063] according to Figure 5The control logic diagram shows that when there is excess electrical energy, the system first determines whether the excess energy originates from wind turbines or the land power grid, and then closes control switches K1 and K3 in the corresponding control circuit. This allows the system to detect excess electrical energy at the source and put the system into pumped water storage mode. Control switch K2 closes, simultaneously opening the water inlet at the bottom of the tower to allow seawater to flow into the water chamber inside the tower. The system also checks whether the water pump inside the tower is functioning properly and whether the permanent magnet or excitation turbine generator needs to be switched to standby mode to participate in pumped water storage. Finally, the control valves pump water through the seawater drainage channel ② to the reservoir at the top of the tower, completing the control process for pumped water storage when there is excess electrical energy.

[0064] according to Figure 5 The control logic diagram shows that when there is a power shortage in the power grid, the system is put into power generation mode after detection. Based on the actual power generation capacity of the generating units, the power shortage can be compensated in three ways and through their coordination. First, power generation can be increased by controlling the onshore power grid. Second, power generation can be increased by adjusting the offshore wind turbines, requiring the closure of control switches K1 and K3. Third, power generation can be achieved by utilizing the water stored in a seawater tower. First, the inlet or outlet is opened to allow seawater to flow out of the tower. Second, control switches K2 and K3 are closed to feed the generated electricity into the grid. Finally, the valves in the reservoir are opened, allowing water from the top of the tower to flow through the spiral casing and impact the turbine to generate electricity. These three control procedures for compensating for power shortages are parallel procedures, i.e., OR relationships, and can be finely coordinated according to the degree of power shortage.

[0065] according to Figure 5 The control logic diagram shows that when the reactive power of the power grid is unbalanced, the system detects this and can put the system into a phase-shifting state. This means that the permanent magnet or excitation synchronous generator is controlled to operate as a synchronous condenser. The synchronous condenser operates as an unloaded or low-load motor. Before operation, it is necessary to check if the indoor water has been drained; that is, the inlet must be closed and the outlet opened, using the aforementioned water pump to drain the indoor water. Then, control switches K2 and K3 are closed, integrating the reactive power generated by the synchronous condenser into the power grid. Real-time adjustments are made to balance the reactive power of the power grid.

[0066] Through the above description of specific implementation methods, based on the mutual cooperation of various switching elements, complex logic control relationships can be realized, and the system can achieve refined realization of functions such as green pumped storage, power generation and phase regulation at sea, thus realizing the full utilization of marine energy and the effective regulation of the land power grid.

[0067] The following description uses an independent offshore green pumped-storage, phase-regulation, and power generation system as an example to illustrate the system of this invention. This system combines pumped-storage, hydropower generation, and synchronous motor phase regulation technologies. Through their mutual cooperation, it aims to fully utilize and dispatch offshore resources, achieving the function of green pumped-storage. The system includes a green pumped-storage reservoir 1, a drainage channel ② 16, a pump 8 in the water chamber inside the tower, and an excitation or permanent magnet synchronous generator 5 that can be switched to a standby pump, an inlet 21, and related circuit structures 14, 22, 23, 24, 25, and 26. When there is excess electricity from offshore wind turbines or the onshore power grid, this system can store excess electricity through green pumping. Depending on the source of the excess electricity, K1 (24) or K3 (26) can be selectively closed, and K2 (25) can be closed to provide power to the pump 8 in the water chamber inside the tower. When the water pump 8 in the water chamber inside the tower malfunctions or the pumping volume is insufficient, the excitation or permanent magnet synchronous generator can be converted into a synchronous motor 5 and used as a backup water pump. At this time, the inlet 21 with the valve is open, and seawater from outside the tower flows into the water chamber 9 inside the tower. The water pump starts working and sends the seawater through the drainage pipe ②16 to the water storage tank 1 at the top of the tower. This realizes the function of storing excess energy by pumping water to the water storage tank in a green manner.

[0068] Based on the above structure, this system can realize the function of phase regulation at sea. This system includes a water turbine 5, drainage channels ①17 and ②16, a water pump 8 in the water chamber inside the tower, and an excitation or permanent magnet synchronous generator 5 whose operating mode can be changed to synchronous condenser, a discharge outlet 20, and related circuit structures 14, 22, 23, 24, 25, and 26. When the power quality on land is poor, the operating mode of the vertical excitation or permanent magnet synchronous generator 5 changes, making it operate as a synchronous condenser connected to the land power grid 23. It absorbs reactive power from the grid through reactive power compensation, thereby regulating the reactive power of the grid and ensuring the quality of power supply on land.

[0069] When the vertical excitation or permanent magnet synchronous generator 5 absorbs electrical energy from the land power grid 23 and switches to no-load or light-load motor operation state, i.e., synchronous condenser operation state, it needs to first drain the water in the water chamber 9 inside the tower. Based on the existing structure, several methods for draining the water in the chamber are proposed here.

[0070] Firstly, a specific water pump is installed in the water turbine 5, which drains the indoor water through a separate channel 18 when the vertical excitation or permanent magnet synchronous generator 5 rotates.

[0071] Secondly, by using the water pump 8 in the water chamber inside the tower, the water inside is drained through a specific channel 19 by drawing on the power of the land power grid 23, the power of the surrounding wind turbine group 10, or the power stored in the tower.

[0072] Thirdly, to make the pumping process faster, one method can be used in combination with the other, and the channels for both methods can be shared.

[0073] The aforementioned channels can be selected as either drainage channel ①17 or drainage channel ②16, depending on the actual situation, to drain the water in the water chamber inside the tower into the reservoir 1 above the water tower or directly into the sea through the outlet 20. When realizing the offshore phase modulation function, control switches K2 and K3 are closed, and K1 is open. The vertical excitation or permanent magnet synchronous generator 5 is connected to the land power grid 23 in the state of synchronous condenser. The inlet 21 is closed, and the water in the water chamber 9 inside the tower is emptied in the above manner. At this point, the synchronous generator operates in the state of no-load or light-load motor, absorbing the reactive power of the land power grid 23 and driving the water turbine 5 to idle, thereby completing the regulation of the reactive power of the land power grid and realizing the function of improving the power supply quality of the land power grid through offshore phase modulation.

[0074] Based on the above structure, this system can realize the function of offshore power generation. The system includes a wind turbine 10, a tower top water storage tank 1, a spiral casing 3, an excitation or permanent magnet synchronous generator 5 that is vertically coaxial with the turbine, a water chamber 9 inside the tower, a water inlet 21, a discharge outlet 20, and related circuit structures 14, 22, 23, 24, 25, and 26.

[0075] Firstly, this structure contains a wind turbine or a group of wind turbines 10, whose generated electrical energy can be connected to the terrestrial power grid 23 in a traditional manner after passing through a frequency modulator, thus realizing the grid connection of wind power generation.

[0076] Secondly, when the offshore wind turbine needs to be shut down due to objective factors, in this structure, the power can be generated by an excitation or permanent magnet synchronous generator 5 in a form similar to that of a hydro turbine generator and then connected to the land power grid 23.

[0077] Thirdly, during peak electricity demand periods, both of the above power generation methods can be used simultaneously for offshore power generation to compensate for power shortages. When using wind turbines, the process is similar to the past, where the rotation of the fan blades 15 drives the generator to rotate, which then generates electricity via a controller. The difference lies in the location of the wind turbine's frequency regulator, which can be placed inside the wind turbine or inside the water tower. In this case, K1 and K3 are closed, and K2 can be open. When using a vertical excitation or permanent magnet synchronous generator 5, K2 and K3 are closed, and K1 can be open. The valve 2 below the reservoir opens, and the water above flows downwards due to gravity, passing through the volute 3 channel and exiting through the drain outlet 4, impacting the turbine blades 6. The rotating blades drive the excitation or permanent magnet synchronous generator 5 to generate electricity. Additionally, the water flowing out through the turbine blades 6 flows into the water chamber 9 inside the tower. At this time, it is necessary to ensure that the inlet 21 or the outlet 20 is open, and to discharge excess seawater outside the tower. Thus, by utilizing the seawater in the reservoir at the top of the tower through green pumped water storage, this system has achieved the function of generating electricity jointly by wind turbines and hydro turbines, realizing offshore power generation.

[0078] In summary, the offshore green pumped-storage, phase-modulation, and power generation system proposed in this invention can address the problem of insufficient and inefficient utilization of offshore wind power resources. This system stores uncontrollable natural wind energy as the potential energy of water within the tower by constructing a water tower connected to an offshore wind turbine. Power is then generated by a synchronous generator installed within the tower, effectively utilizing offshore wind power. Simultaneously, the tower is connected to the onshore power grid. When the onshore power grid quality is poor, the synchronous generator acts as a phase condenser, absorbing reactive power from the onshore grid and ensuring the quality of onshore power. Therefore, this invention, through green pumped-storage, phase-modulation, and power generation, achieves both full utilization of offshore wind power resources and ensures the reliability of onshore power supply.

[0079] Those skilled in the art will understand that the accompanying drawings are merely schematic diagrams of one embodiment, and the modules or processes shown in the drawings are not necessarily essential for implementing the present invention.

[0080] As can be seen from the above description of the embodiments, those skilled in the art can clearly understand that the present invention can be implemented by means of software plus necessary general-purpose hardware platforms. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in various embodiments or some parts of the embodiments of the present invention.

[0081] The various embodiments in this specification are described in a progressive manner. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, for apparatus or system embodiments, since they are basically similar to method embodiments, the description is relatively simple; relevant parts can be referred to the descriptions in the method embodiments. The apparatus and system embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without creative effort.

[0082] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A marine green pumped-storage, phase-regulation, and power generation system, characterized in that, include: The system includes a wind turbine or wind turbine cluster, an offshore water tower, a water turbine, an excitation or permanent magnet synchronous generator, and a water pump. The excitation or permanent magnet synchronous generator is located inside the offshore water tower. The wind turbine or wind turbine cluster is located at the top of the offshore water tower or distributed around the offshore water tower. The vertical excitation or permanent magnet synchronous generator is coaxially connected to the water turbine. The offshore water tower is equipped with a lower drainage outlet with a volute. A water storage tank is provided above the offshore water tower. The bottom of the offshore water tower is equipped with an internal water chamber, an internal drainage channel, a discharge outlet, a water inlet, and corresponding valves and related circuit structures. The offshore water tower is constructed of reinforced concrete. A water storage tank is installed on top of the offshore water tower. The water storage tank is connected to the volute below the water storage tank via a valve below the water storage tank. A water flow channel located below the volute is installed inside the volute and is connected to the blades of the water turbine generator. The water flow drives a vertically placed excitation or permanent magnet synchronous generator through the volute. The excitation or permanent magnet synchronous generator is fixed on the tower body by a support frame. A water chamber is provided below the offshore water tower. The water chamber is connected to the seawater outside the tower through a water inlet and corresponding valves. A water pump is installed in the water chamber. The seawater pumped out by the water pump is discharged into the sea through a drainage channel and a sea outlet and corresponding valves, or discharged into a water storage tank above the water tower through a drainage channel. The system is equipped with switches K1, K2 and K3. Switch K1 is connected to the offshore wind turbine, switch K2 is connected to the power grid inside the water tower, and switch K3 is connected to the land power grid. The functions of offshore green pumped water storage, phase regulation and power generation are realized by controlling the switch elements K1, K2 and K3. The offshore wind turbine is equipped with a wind turbine, a generator and a controller. When the reactive power of the power grid is unbalanced, the system is placed in phase adjustment mode, and the permanent magnet or excitation synchronous generator is operated to the synchronous condenser mode. The synchronous condenser is in the motor state of no-load or low-load operation. The water inlet is closed and the outlet to the sea is opened. After the indoor water is emptied by the water pump, the control switches K2 and K3 are closed to integrate the reactive power generated by the synchronous condenser into the power grid. The reactive power of the power grid is balanced through real-time adjustment.

2. The system according to claim 1, characterized in that, When there is excess power in the power grid, if the source of the excess power is determined to be excess power generation from wind turbines, the control switch K1 in the corresponding control circuit is closed. If the source of the excess power is determined to be excess power generation from the land power grid, the control switch K3 in the corresponding control circuit is closed, so that the system can detect the excess power on the source side and put the system into pumped water storage state. The control switch K2 is closed, the water inlet at the bottom of the tower is opened, and seawater is allowed to flow into the water chamber inside the tower. The system checks whether the water pump inside the tower can work normally and whether it is necessary to run the permanent magnet or excitation turbine generator to the standby water pump state to participate in pumped water storage. The seawater is pumped to the water storage tank at the top of the tower through the drainage channel ② by controlling the valve.

3. The system according to claim 1, characterized in that, When there is a power shortage in the power grid, the system is put into generating mode, and the power shortage is made up by one or more of the following three power generation methods based on the actual power generation capacity of the generating units: Power generation method 1: Increase power generation by controlling the terrestrial power grid; Power generation method 2: Close control switches K1 and K3 to increase power generation by adjusting the offshore wind turbine. Power generation method three: Close control switches K2 and K3 to send the generated electricity into the power grid, use the water stored in the water tower to generate electricity, open the water inlet or outlet to let seawater flow out of the tower, open the valve of the water storage tank, and let the water at the top of the tower pass through the spiral casing and impact the water turbine to generate electricity.

4. The system according to any one of claims 1 to 3, characterized in that, In an independent offshore green pumped storage, phase regulation and power generation system, one or a group of wind turbines are installed. The wind turbines are integrated with the water tower and located at the top of the tower, with no other wind turbines around them. In the distributed offshore green pumped storage, phase regulation and power generation system, the top of the water tower is not equipped with a wind turbine, but the wind turbine group is distributed around the water tower to form a wind turbine network and is connected to the water tower. One or more wind turbines are installed on top of the water tower of a centralized offshore green pumped storage, phase regulation and power generation system. The wind turbines and the water tower are integrated. A group of wind turbines is also installed around the water tower, which is connected to the water tower and together provides power to the system.

5. The system according to claim 4, characterized in that, The independent offshore green pumped storage, phase regulation and power generation system is equipped with a green pumped storage reservoir, drainage channel, pumps in the water chamber inside the tower, an excitation or permanent magnet synchronous generator that can be changed to a standby pump, a sea inlet, and related circuit structures. When there is excess power from offshore wind turbines or the onshore power grid, the system stores excess power through green pumping. When the pumps in the water chamber inside the tower fail or the pumping volume is insufficient, the excitation or permanent magnet synchronous generator is converted to a synchronous motor and used as a standby pump. The inlet with valve is in the open state, seawater from outside the tower flows into the water chamber inside the tower, the pumps start working, and the seawater is sent to the reservoir at the top of the tower through the drainage pipe.

6. The system according to claim 5, characterized in that, The electrical energy generated by the wind turbine or wind turbine group is connected to the terrestrial power grid after passing through a frequency regulator, realizing the grid connection of wind power generation; when the wind turbine or wind turbine group needs to be shut down, it generates electricity through an excitation or permanent magnet synchronous generator and connects it to the terrestrial power grid. The frequency regulator of the wind turbine is located inside the wind turbine or in the offshore water tower. Switch K1, which is connected to the offshore wind turbine, and switch K3, which is connected to the land power grid, are closed. Switch K2, which is connected to the power network inside the water tower, is open. The valve under the water tank is opened. The water above the water tank flows out of the drain outlet through the spiral casing channel and impacts the turbine blades. The blades rotate and drive the excitation or permanent magnet synchronous generator to generate electricity. The water flowing out of the turbine blades will flow into the water chamber inside the tower. The inlet or outlet is open to discharge excess seawater outside the tower.

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