A fan coupling compressed air energy storage power generation system and method

Abstract

The application discloses a wind turbine coupled compressed air energy storage power generation system and method. The system comprises a wind energy compression system, a heat and air storage system and an expansion power generation system. The wind energy compression system is used for air compression. The heat and air storage system is used for heat storage and air storage of the compressed air with heat. The expansion power generation system is used for expansion of the stored air to drive a generator to generate and output electric energy to a grid.

Description

Technical Field

[0001] This invention relates to the field of wind power generation technology, and more specifically, to a power generation system and method that couples a wind turbine with compressed air energy storage. Background Technology

[0002] Power electronic equipment is connected to the grid and ultimately transmitted via AC or DC transmission systems. However, the uncontrollable and unpredictable nature of wind energy leads to fluctuations in wind farm power generation, posing a challenge to the frequency stability of the power system. Furthermore, with the increase in installed capacity of new energy sources, the system inertia level, primarily supported by synchronous turbines, is rapidly declining, resulting in a low short-circuit ratio at the grid's end. Wind power converters track the phase of the grid connection voltage through phase-locked loops (PLLs), and weak grid environments can cause deterioration in PLL control performance, leading to problems such as subsynchronous / supersynchronous oscillations.

[0003] With the development of new power systems, effectively utilizing wind energy and achieving stable grid connection and power generation for wind farms is crucial for the development of wind power technology. Two key issues urgently need to be addressed: the stability of wind power grid connection to weak grids; and the uncertainty in wind turbine power generation caused by random fluctuations in wind resources.

[0004] To address the stability issues of wind power grid connection in weak grid environments, current solutions mainly include: optimizing grid-connected control strategies, adopting grid-based control strategies, adding grid-based energy storage or SVG (Static Var Generator), and adding synchronous condensers. For wind power output fluctuations, current solutions mainly include: adding energy storage devices and coordinating control with nearby traditional power plants.

[0005] Wind turbines have low inherent inertia, making them unable to provide effective support to the power grid. The stable operation of traditional power systems heavily relies on the inertia, short-circuit capacity, voltage support, and frequency formation capabilities provided by synchronous generators. Therefore, integrating wind farms with energy storage technologies based on synchronous generators is one solution for achieving efficient wind energy utilization and stable grid connection. Currently, technologies based on synchronous generators and capable of large-scale energy storage include pumped hydro storage and compressed air energy storage. Pumped hydro storage requires proximity to a water source and the construction of two reservoirs (one high and one low), placing high demands on geographical conditions. Compressed air energy storage, on the other hand, has no such geographical requirements. Connected to the grid via synchronous generators, it can increase the power system's inertia and can be used for long-term, large-capacity energy storage, offering advantages such as long charging and discharging times.

[0006] Currently, wind energy is captured by wind turbine blades to drive generators and generate electricity via power electronic devices connected to the grid. Grid-connected converters, which serve as the interface between wind turbines and the power grid, often employ grid-following control based on phase-locked loop synchronization. Their external operating characteristics exhibit current source characteristics, and their operation depends on the AC grid formation capability provided by synchronous generators.

[0007] Under the above operating mode, the existing wind power system mainly has the following problems: 1. Wind power output is directly affected by wind speed and is difficult to actively adjust. 2. Operational stability is limited under weak grid conditions or grid conditions with low short-circuit ratios. 3. The system operation depends on the external AC voltage environment, and its islanding capability is insufficient.

[0008] Meanwhile, existing compressed air energy storage systems typically use electric motors to drive compressors, and the energy storage process occurs after the electrical energy conversion. Wind power and energy storage are coupled electrically, resulting in a relatively long energy conversion path. Summary of the Invention

[0009] To address the shortcomings of existing technologies, this invention provides a power generation system and method that uses a wind turbine coupled with compressed air energy storage.

[0010] According to one aspect of the present invention, a wind turbine coupled with compressed air energy storage is provided for a power generation system, comprising: a wind energy compression system, a thermal and gas storage system, and an expansion power generation system, wherein... Wind energy compression systems are used to compress air; Thermal and gas storage systems are used for the thermal and air storage of compressed air. An expansion power generation system is used to expand stored air to drive a generator to generate electricity for grid connection.

[0011] Optionally, the wind energy compression system includes a wind turbine and a compressor, wherein Wind turbines capture wind energy through blades and drive the main shaft to rotate. The main shaft is directly or through a transmission mechanism connected to a compressor, which compresses the air to produce high-temperature and high-pressure air. Multiple wind turbines are equipped with multiple compressors, and the outlet of each compressor is connected to the main air collection pipe through a pipeline to realize the collection and transportation of compressed air.

[0012] Optionally, the power input end of the compressor is directly connected to the power output end of the wind turbine via mechanical transmission, and the wind turbine drives the compressor to compress the air and perform work.

[0013] Optionally, the mechanical transmission method includes any of the following: The main shaft of the wind turbine is directly connected to the input shaft of the compressor via a coupling; The main shaft of the wind turbine is connected to the input shaft of the compressor through a transmission mechanism.

[0014] Optionally, it also includes: a gas collection pipeline system for delivering compressed air from the wind power compression system to the thermal and energy storage system.

[0015] Optionally, the thermal and gas storage system includes: a heat exchange and thermal storage system and a gas storage system, wherein the heat exchange and thermal storage system includes a heat exchange device and a thermal storage system, wherein... Compressed air first enters the heat exchanger, where it transfers heat to the heat storage system for storage; after being cooled, the compressed air enters the air storage system for storage.

[0016] Optionally, the gas storage system is a high-pressure gas storage tank, an underground gas storage cavern, or a salt cavern gas storage space, and the gas storage system is equipped with a pressure monitoring device, a safety valve, and a control valve.

[0017] Optionally, the expansion power generation system includes an expander and a synchronous generator, wherein When power generation is needed, the release channel of the gas storage system is opened, and compressed air enters the heat exchanger through pipelines. After absorbing heat from the heat storage system and becoming warm, the compressed air enters the expander. The expander expands under the action of the compressed air, driving the synchronous generator to generate electricity. The synchronous generator outputs electrical energy and operates in parallel with the grid. Optionally, the system's power generation can be continuously adjusted by regulating the compressed air release flow rate or the opening of the expander's inlet guide vanes.

[0018] According to another aspect of the present invention, a power generation method for wind turbine coupled compressed air energy storage is provided, comprising: When the wind speed reaches the cut-in wind speed, the wind turbine captures wind energy and drives the compressor to compress the air to produce high-temperature and high-pressure air; the compressed air enters the heat exchange and storage system through the air collection pipeline system for heat recovery and is then stored in the air storage system. When power support is needed, compressed air is released from the gas storage system; the compressed air enters the heat exchange and storage system to absorb heat, then enters the expander to expand and do work, driving the generator to generate electricity. Based on the gas storage pressure, thermal storage temperature, and grid demand, the energy storage process and the power generation process are coordinated and controlled.

[0019] Optionally, it also includes: achieving independent adjustment of power generation by adjusting the compressed air release flow rate or adjusting the expansion turbine inlet guide vane opening, thereby decoupling wind power output from grid demand.

[0020] According to another aspect of the present invention, a computer-readable storage medium is provided, the storage medium storing a computer program for performing the methods described in any of the above aspects of the present invention.

[0021] According to another aspect of the present invention, an electronic device is provided, the electronic device comprising: a processor; a memory for storing executable instructions of the processor; the processor being configured to read the executable instructions from the memory and execute the instructions to implement the method described in any of the preceding aspects of the present invention.

[0022] Therefore, unlike traditional wind farms that collect electrical energy through electrical lines, this invention collects energy internally in the form of compressed air, and then generates electricity through a synchronous generator after the gas storage system. This method reduces the use of power electronic equipment and can be used for wind power islanding, helping to improve the system's short-circuit ratio. Attached Figure Description

[0023] Exemplary embodiments of the present invention can be more fully understood by referring to the following figures: Figure 1 This is a schematic diagram of the structure of a wind turbine coupled with compressed air energy storage power generation system provided in an exemplary embodiment of the present invention; Figure 2 This is a schematic flowchart of a power generation method for wind turbine coupled compressed air energy storage provided in an exemplary embodiment of the present invention. Detailed Implementation

[0024] Hereinafter, exemplary embodiments according to the present invention will be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are merely some embodiments of the present invention, and not all embodiments of the present invention. It should be understood that the present invention is not limited to the exemplary embodiments described herein.

[0025] It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of the invention.

[0026] Those skilled in the art will understand that the terms "first," "second," etc., in the embodiments of the present invention are only used to distinguish different steps, devices, or modules, and do not represent any specific technical meaning, nor do they indicate a necessary logical order between them.

[0027] It should also be understood that in the embodiments of the present invention, "multiple" can refer to two or more, and "at least one" can refer to one, two or more.

[0028] It should also be understood that any component, data or structure mentioned in the embodiments of the present invention can generally be understood as one or more unless explicitly defined or given contrary instructions in the context.

[0029] Furthermore, the term "and / or" in this invention is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this invention generally indicates that the preceding and following related objects have an "or" relationship.

[0030] It should also be understood that the description of the various embodiments in this invention emphasizes the differences between the various embodiments, and the similarities or similarities can be referred to each other. For the sake of brevity, they will not be described in detail.

[0031] At the same time, it should be understood that, for ease of description, the dimensions of the various parts shown in the accompanying drawings are not drawn according to actual scale.

[0032] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the invention or its application or use.

[0033] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, they should be considered part of the specification.

[0034] It should be noted that similar labels and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be discussed further in subsequent figures.

[0035] Figure 1 This is a schematic diagram of a wind turbine-coupled compressed air energy storage power generation system provided in an exemplary embodiment of the present invention. Figure 1 As shown, the wind turbine coupled with compressed air energy storage power generation system includes: a wind energy compression system, a thermal and gas storage system, and an expansion power generation system, wherein... Wind energy compression systems are used to compress air; Thermal and gas storage systems are used for the thermal and air storage of compressed air. An expansion power generation system is used to expand stored air to drive a generator to generate electricity for grid connection.

[0036] Specifically, in response to the background problems, the purpose of this invention is to provide a wind turbine integrated compressed air energy storage and power generation system. By changing the energy transfer path inside the wind farm, the mechanical output of the wind turbine is directly used to drive the compressor, so that wind energy enters the energy storage system before being converted into electrical energy, thereby constructing a physical coupling structure between wind power and energy storage.

[0037] Through the above structural arrangement, the wind turbine transforms from a traditional power generation device into a compressed power source, with energy storage occurring before power generation. This alters the functional roles and energy organization of the wind power system. Based on this topology, the system's output power is provided by a synchronous generator driven by an expander, enabling AC voltage support. Structurally, this distinguishes it from grid-connected wind power systems that rely on power electronic converters, making it suitable for islanded wind power operation and low short-circuit ratio grid-connected scenarios.

[0038] To address the issues of existing wind power systems' output power being affected by wind speed fluctuations, and the problems of traditional compressed air energy storage systems often using electric motors to drive compressors and having multiple energy conversion stages, this invention aims to provide a wind turbine coupled compressed air energy storage and power generation system. By optimizing the system topology, it achieves the integration of mechanical direct-drive compression of wind energy with energy storage and power generation, thereby improving the simplicity of the system structure and the flexibility of operation.

[0039] The wind turbine-coupled compressed air energy storage and power generation system provided by this invention mainly includes: a wind turbine, a compressor, an air collection pipeline system, a heat exchange and storage system, an air storage system, and an expansion power generation system. These units are connected through pipelines and mechanical transmission structures to form a complete wind energy storage and power generation system. The connection relationships between the above systems are as follows: 1) Wind energy compression system Wind turbines capture wind energy through their blades and drive the main shaft to rotate. The main shaft is directly or through a transmission mechanism connected to a compressor, which in turn compresses the air to produce high-temperature, high-pressure air. Multiple wind turbines are equipped with multiple compressors, and the outlet of each compressor is connected to a main air collection pipe through pipelines to achieve the collection and transportation of compressed air.

[0040] Specifically, a wind turbine captures wind energy through its blades, which then drive the main shaft to rotate. The main shaft is connected to a compressor via a coupling or transmission mechanism, driving the compressor to compress air and generate high-pressure air. The compression unit includes at least one compressor. The compressor can be centrifugal or axial flow type. The high-temperature, high-pressure air generated during compression is delivered to the air collection pipeline system via an outlet pipeline. Multiple wind turbines are equipped with multiple compressors, and the outlet of each compressor is connected to the main air collection pipeline to achieve centralized delivery of compressed air.

[0041] 2) Thermal and gas storage systems Because the temperature of compressed air rises significantly during compression, to improve circulation efficiency, the compressed air first enters a heat exchanger to transfer heat to a heat storage system for storage. The cooled compressed air then enters a gas storage system for further storage. This gas storage system can be a high-pressure gas tank, an underground gas storage cavern, or a salt cavern gas storage space.

[0042] Specifically, compressed air enters the heat exchange system via a collection pipeline. The heat exchange unit is connected to the heat storage unit, transferring the heat from the compressed air to the storage unit for storage. In this embodiment, the heat storage system is a heat storage structure, including heat storage material, heat exchange channels, and insulation structure. The heat storage material can be sensible heat storage material, latent heat storage material, or thermochemical material. The compressed air, cooled by heat exchange, enters the gas storage system. The gas storage system is a closed pressure vessel or underground gas storage space used to store compressed air. The gas storage system is equipped with a pressure monitoring device, safety valve, and control valve.

[0043] 3) Expansion power generation system When power generation is needed, the release channel of the gas storage unit is opened, and compressed air enters the heat exchange device through a pipeline. After absorbing heat from the heat storage system and heating up, it enters the expander. The expander expands under the action of compressed air, performing work to drive the generator to generate electricity. The generator outputs electrical energy and operates in parallel with the grid. The system's power generation is continuously adjustable by regulating the compressed air release flow rate or adjusting the opening of the expander's inlet guide vanes.

[0044] 4) System topology characteristics The energy transfer path of this invention is as follows: Wind turbine main shaft → compressor → gas collection pipeline → thermal and gas storage system → expansion power generation unit.

[0045] The operation mode is as follows: when the wind speed reaches the minimum cut-in wind speed, the wind turbine drives the compressor to compress air, realizing energy storage operation; when the grid needs power support, the compressed air in the gas storage unit is released to drive the expansion power generation unit to generate electricity; the control and regulation unit coordinates and controls according to the gas storage pressure, thermal storage temperature, and grid demand. The gas filling and releasing processes can be carried out simultaneously. This system can achieve hourly energy storage regulation capability by changing the gas storage scale.

[0046] Therefore, unlike traditional wind farms that collect electrical energy through electrical lines, this invention collects energy internally in the form of compressed air, and then generates electricity through a synchronous generator after the gas storage system. This method reduces the use of power electronic equipment and can be used for wind power islanding, helping to improve the system's short-circuit ratio.

[0047] also, Figure 2 This application provides a schematic flowchart of a power generation method using wind turbine coupled compressed air energy storage, according to another aspect of this application. (Refer to...) Figure 2 As shown, the power generation method 200 using wind turbine coupled with compressed air energy storage specifically includes: Step 201: When the wind speed reaches the cut-in wind speed, the wind turbine captures wind energy and drives the compressor to compress the air to generate high-temperature and high-pressure air; the compressed air enters the heat exchange and storage system through the air collection pipeline system for heat recovery and is then stored in the air storage system. Step 202: When power support is needed, release the compressed air in the gas storage system; after the compressed air enters the heat exchange and storage system to absorb heat, it enters the expander to expand and do work, driving the generator to generate electricity; Step 203: Coordinate and control the energy storage process and the power generation process based on the gas storage pressure, thermal storage temperature and grid demand.

[0048] Optionally, method 200 further includes: achieving independent adjustment of power generation by adjusting the compressed air release flow rate or adjusting the expansion turbine inlet guide vane opening, thereby decoupling wind power output from grid demand.

[0049] The above description has been given for purposes of illustration and description. Furthermore, this description is not intended to limit the embodiments of the invention to the forms disclosed herein. Although numerous exemplary aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, alterations, additions, and sub-combinations thereof.

Claims

1. A power generation system that couples a wind turbine with compressed air energy storage, characterized in that, include: Wind power compression systems, thermal and gas storage systems, and expansion power generation systems, among which The wind energy compression system is used to compress air; The heat storage and air storage system is used for heat storage and air storage of compressed air containing heat. The expansion power generation system is used to expand stored air to drive a generator to generate electricity for grid connection.

2. The system according to claim 1, characterized in that, The wind energy compression system includes a wind turbine and a compressor, wherein The wind turbine captures wind energy through its blades and drives the main shaft to rotate. The main shaft is directly or through a transmission mechanism connected to the compressor, which in turn compresses the air to produce high-temperature, high-pressure air. Multiple wind turbines are equipped with multiple compressors, and the outlet of each compressor is connected to the main air collection pipe through a pipeline to realize the collection and transportation of compressed air.

3. The system according to claim 2, characterized in that, The power input end of the compressor is directly connected to the power output end of the wind turbine through mechanical transmission, and the wind turbine drives the compressor to compress air and perform work.

4. The system according to claim 3, characterized in that, The mechanical transmission method includes any of the following: The main shaft of the wind turbine is directly connected to the input shaft of the compressor via a coupling; The main shaft of the wind turbine is connected to the input shaft of the compressor via a transmission mechanism.

5. The system according to claim 1, characterized in that, Also includes: The air collection pipeline system is used to transport compressed air from the wind power compression system to the heat storage and energy storage system.

6. The system according to claim 1, characterized in that, The thermal and gas storage system includes: a heat exchange and thermal storage system and a gas storage system. The heat exchange and thermal storage system includes a heat exchange device and a thermal storage system. Compressed air first enters the heat exchange device, transferring heat to the heat storage system for storage; the cooled compressed air then enters the air storage system for storage.

7. The system according to claim 6, characterized in that, The gas storage system is a high-pressure gas storage tank, an underground gas storage cavern, or a salt cavern gas storage space. The gas storage system is equipped with a pressure monitoring device, a safety valve, and a control valve.

8. The system according to claim 6, characterized in that, The expansion power generation system includes an expander and a synchronous generator, wherein... When power generation is needed, the release channel of the gas storage system is opened, and compressed air enters the heat exchange device through the pipeline. After absorbing heat from the heat storage system and becoming warm, the compressed air enters the expander. The expander expands and does work under the action of the compressed air, driving the synchronous generator to generate electricity. The synchronous generator outputs electrical energy and operates in parallel with the grid.

9. The system according to claim 8, characterized in that, The system's power generation is continuously adjustable by regulating the compressed air release flow rate or adjusting the opening of the expander's inlet guide vanes.

10. The power generation method for wind turbine coupled compressed air energy storage implemented according to any one of claims 1-9, characterized in that, include: When the wind speed reaches the cut-in wind speed, the wind turbine captures wind energy and drives the compressor to compress the air to produce high-temperature and high-pressure air; the compressed air enters the heat exchange and storage system through the air collection pipeline system for heat recovery and is then stored in the air storage system. When power support is needed, the compressed air in the gas storage system is released; the compressed air enters the heat exchange and storage system to absorb heat, then enters the expander to expand and do work, driving the generator to generate electricity; Based on the gas storage pressure, thermal storage temperature, and grid demand, the energy storage process and the power generation process are coordinated and controlled.

11. The method according to claim 10, characterized in that, Also includes: By adjusting the compressed air release flow rate or the expansion turbine inlet guide vane opening, the power generation can be independently adjusted, thus decoupling wind energy output from grid demand.

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