Water storage energy storage and compressed gas energy storage combined energy storage system and control method thereof

Abstract

The invention discloses a water storage energy storage and compressed gas energy storage combined energy storage system and a control method. The energy storage system comprises a compressed gas energy storage subsystem, a water storage energy storage subsystem and a power coordination controller. The water storage and energy storage subsystem is used for providing first output power to enable the energy storage system to rapidly reach rated output power, and reducing the first output power to enable the energy storage system to maintain the rated output power in the process that the second output power of the compressed gas energy storage subsystem is increased to the rated output power; and the power coordination controller is used for coordinating and controlling the first output power of the water storage and energy storage subsystem according to the second output power of the compressed gas energy storage subsystem, so that the sum of the second output power and the first output power is kept as the rated output power. The energy storage system has the advantages that in the energy release stage, the energy storage system can be quickly connected to the power grid by utilizing the quick response of the water storage and energy storage subsystem, and the waste of electric energy is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of energy storage systems, and in particular to an energy storage system combining water energy storage with compressed gas energy storage and a control method thereof. Background Art

[0002] Compressed air energy storage technology is a physical energy storage technology that uses compressed air to store energy. It has the advantages of large energy storage capacity, high safety, economy, environmental protection and mature technology. It plays an important role in the future energy system, especially in promoting the use of renewable energy and improving the stability of the power grid.

[0003] In the application of existing technology, during the low electricity price period, normal pressure gas is converted into high pressure gas through a multi-stage compressor, and the electrical energy is converted into the internal energy of the high pressure gas for storage; during the peak electricity consumption period, the high pressure gas is expanded into normal pressure gas through a multi-stage expander to generate electricity, and finally the storage and release of electrical energy are realized. However, there are some disadvantages. The startup response time of the expander is more than 6 minutes, and it cannot respond quickly, that is, it will not generate electricity immediately after startup, and the power generation power needs a period of time to reach the peak, that is, it cannot be connected to the power grid before the output power is stable, and the power generation during this period is wasted, which needs to be improved. Summary of the invention

[0004] A technical problem to be solved by the present application is to overcome the defects of the above-mentioned related technologies and provide an energy storage system and a control method thereof which combines water storage and compressed gas energy storage with fast response speed and less power waste.

[0005] The technical solution adopted by this energy storage system to solve the technical problem is: an energy storage system combining water storage and compressed gas storage, including a compressed gas storage subsystem,

[0006] It also includes a water storage subsystem and a power coordination controller, and the compressed gas energy storage subsystem and the water storage subsystem are electrically connected to the power coordination controller respectively;

[0007] The water storage subsystem is used to provide a first output power so that the energy storage system quickly reaches the rated output power, and to reduce the first output power during the process of increasing the second output power of the compressed gas energy storage subsystem to the rated output power so that the energy storage system maintains the rated output power;

[0008] The power coordination controller is used to coordinate and control the first output power of the water storage subsystem according to the second output power of the compressed gas energy storage subsystem, so that the sum of the second output power and the first output power remains at the rated output power.

[0009] Compared with related technologies, this energy storage system has the following advantages: in the energy release stage, the rapid response of the water storage subsystem is used to fill the gap, avoiding the defects of the compressed gas energy storage subsystem not generating electricity immediately after startup and the power generation taking a long time to reach the peak. This enables the energy storage system to quickly connect to the power grid and reduce the waste of electricity.

[0010] Preferably, it also includes a compressed gas energy storage power coordination actuator and a water energy storage power coordination actuator, and the power coordination controller is electrically connected to the compressed gas energy storage power coordination actuator and the water energy storage power coordination actuator respectively;

[0011] The compressed gas energy storage power coordination actuator is used to adjust the exhaust speed of the compressed gas energy storage subsystem according to the instructions of the power coordination controller;

[0012] The water storage and energy storage power coordination actuator is used to adjust the drainage flow of the water storage and energy storage subsystem according to the instructions of the power coordination controller.

[0013] As an improvement, the gas-compressed energy storage subsystem includes a steel gas storage tank disposed in the mountain, and the water-storage energy storage subsystem includes an upper water storage tank disposed at the top of the mountain and a lower water storage tank at the foot of the mountain. The energy storage system is constructed using natural mountains to reduce construction costs.

[0014] The technical solution adopted by the control method to solve the technical problem is: a control method for an energy storage system combining water energy storage and compressed gas energy storage as described above,

[0015] Energy release process: During the peak period of electricity consumption in the daytime, the compressed gas energy storage subsystem releases the compressed gas in the steel gas tank through the expansion turbine generator to generate electricity. At the same time, the water storage subsystem opens the valve, and the water in the upper water tank flows to the lower water tank to generate electricity. The power coordination controller sends an instruction to the water storage power coordination actuator based on the first output power of the water storage subsystem to maintain the corresponding valve opening when the first output power reaches the rated output power; when the power generation power of the compressed gas energy storage subsystem begins to rise, the power coordination controller sends an instruction to the water storage power coordination actuator to reduce the valve opening based on the second output power of the compressed gas energy storage subsystem to reduce the flow of the water storage subsystem, and gradually reduce the first output power to keep the energy storage system at the rated output power.

[0016] Compared with related technologies, this control method has the following advantages: in the energy release stage, the rapid response of the water storage subsystem is used to fill the gap, avoiding the defects of the compressed gas energy storage subsystem not generating electricity immediately after startup and the power generation taking a long time to reach the peak, thereby enabling the energy storage system to quickly connect to the power grid and reducing the waste of electricity.

[0017] Preferably, when the second output power generated by the compressed gas energy storage subsystem reaches a peak value of the rated output power, the valve of the water storage subsystem is closed, so that the energy storage system can enter a dormant state to extend its service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a connection diagram of the energy storage system of the present application that combines water energy storage with compressed gas energy storage.

[0019] Figure 2 It is a curve diagram of regulating the output power of the energy storage system combining water energy storage and compressed gas energy storage in the present application.

[0020] Figure 3 This is a flow chart of regulating the output power of the energy storage system combining water energy storage and compressed gas energy storage in the present application. DETAILED DESCRIPTION

[0021] First, those skilled in the art should understand that these implementations are only used to explain the technical principles of the embodiments of the present application, and are not intended to limit the protection scope of the embodiments of the present application. Those skilled in the art can make adjustments to them as needed to adapt to specific application scenarios.

[0022] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0023] This preferred embodiment is an energy storage system combining water storage and compressed gas energy storage, including a compressed gas energy storage subsystem, a water storage subsystem and a power coordination controller, wherein the compressed gas energy storage subsystem and the water storage subsystem are electrically connected to the power coordination controller respectively;

[0024] The water storage subsystem is used to provide a first output power so that the energy storage system quickly reaches the rated output power, and to reduce the first output power so that the energy storage system maintains the rated output power during the process of increasing the second output power of the compressed gas energy storage subsystem to the rated output power. Figure 2 As shown;

[0025] The power coordination controller is used to coordinate and control the first output power of the water storage subsystem according to the second output power of the compressed gas energy storage subsystem, so that the sum of the second output power and the first output power remains at the rated output power.

[0026] like Figure 3 As shown, specifically, it also includes a compressed gas energy storage power coordination actuator and a water storage energy storage power coordination actuator, and the power coordination controller is electrically connected to the compressed gas energy storage power coordination actuator and the water storage energy storage power coordination actuator respectively;

[0027] The compressed gas energy storage power coordination actuator is used to adjust the exhaust speed of the compressed gas energy storage subsystem according to the instructions of the power coordination controller;

[0028] The water storage and energy storage power coordination actuator is used to adjust the drainage flow of the water storage and energy storage subsystem according to the instructions of the power coordination controller.

[0029] In this embodiment, if Figure 1 As shown, the compressed gas energy storage subsystem includes a steel gas tank arranged in the mountain and sealed with concrete to slow down the oxidation corrosion of the steel gas tank and increase its service life; the water storage energy storage subsystem includes an upper water tank arranged at the top of the mountain and a lower water tank at the foot of the mountain, a pipeline laid along the mountain connects the upper water tank and the lower water tank, a hydroelectric generator is provided at the bottom of the pipeline, and the power output power of the hydroelectric generator can be adjusted by the opening of the valve at the top of the pipeline.

[0030] The control method of the energy storage system combining water storage and compressed gas storage is as follows:

[0031] Energy storage process: During the low-peak period of electricity consumption at night, the compressed gas energy storage subsystem compresses air into a steel gas tank through a compressor for energy storage; at the same time, the water storage subsystem pumps all the water in the lower reservoir to the upper reservoir on the top of the mountain to complete the energy storage of compressed gas and stored water.

[0032] Energy release process: During the peak period of electricity consumption in the daytime, the compressed gas energy storage subsystem releases the compressed gas in the steel gas tank through the expansion turbine generator to generate electricity. At the same time, the water storage subsystem opens the valve, and the water in the upper water tank flows to the lower water tank to generate electricity. The power coordination controller sends an instruction to the water storage power coordination actuator based on the first output power of the water storage subsystem to maintain the corresponding valve opening when the first output power reaches the rated output power; when the power generation power of the compressed gas energy storage subsystem begins to rise, the power coordination controller sends an instruction to the water storage power coordination actuator to reduce the valve opening based on the second output power of the compressed gas energy storage subsystem to reduce the flow of the water storage subsystem, and gradually reduce the first output power to keep the energy storage system at the rated output power.

[0033] When the second output power generated by the compressed gas energy storage subsystem reaches a peak value of the rated output power, the valve of the water storage subsystem is closed.

[0034] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. An energy storage system combining water storage and compressed gas storage, comprising a compressed gas storage subsystem, It is characterized in that It also includes a water storage subsystem and a power coordination controller, and the compressed gas energy storage subsystem and the water storage subsystem are electrically connected to the power coordination controller respectively; The water storage subsystem is used to provide a first output power so that the energy storage system quickly reaches the rated output power, and to reduce the first output power during the process of increasing the second output power of the compressed gas energy storage subsystem to the rated output power so that the energy storage system maintains the rated output power; The power coordination controller is used to coordinate and control the first output power of the water storage subsystem according to the second output power of the compressed gas energy storage subsystem, so that the sum of the second output power and the first output power remains at the rated output power.

2. The energy storage system combining water storage and compressed gas storage according to claim 1, characterized in that: It also includes a compressed gas energy storage power coordination actuator and a water storage energy storage power coordination actuator, and the power coordination controller is electrically connected to the compressed gas energy storage power coordination actuator and the water storage energy storage power coordination actuator respectively; The compressed gas energy storage power coordination actuator is used to adjust the exhaust speed of the compressed gas energy storage subsystem according to the instructions of the power coordination controller; The water storage and energy storage power coordination actuator is used to adjust the drainage flow of the water storage and energy storage subsystem according to the instructions of the power coordination controller.

3. An energy storage system combining water storage and compressed gas storage according to claim 1 or 2, characterized in that: The compressed gas energy storage subsystem includes a steel gas storage tank arranged in the mountain, and the water storage energy storage subsystem includes an upper water storage tank arranged at the top of the mountain and a lower water storage tank at the foot of the mountain.

4. A control method for an energy storage system combining water energy storage and compressed gas energy storage as claimed in any one of claims 1 to 3, characterized in that: Energy release process: During the peak period of electricity consumption in the daytime, the compressed gas energy storage subsystem releases the compressed gas in the steel gas tank through the expansion turbine generator to generate electricity. At the same time, the water storage subsystem opens the valve, and the water in the upper water tank flows to the lower water tank to generate electricity. The power coordination controller sends an instruction to the water storage power coordination actuator based on the first output power of the water storage subsystem to maintain the corresponding valve opening when the first output power reaches the rated output power; when the power generation power of the compressed gas energy storage subsystem begins to rise, the power coordination controller sends an instruction to the water storage power coordination actuator to reduce the valve opening based on the second output power of the compressed gas energy storage subsystem to reduce the flow of the water storage subsystem, and gradually reduce the first output power to keep the energy storage system at the rated output power.

5. The control method of the energy storage system combining water energy storage and compressed gas energy storage according to claim 4, characterized in that: When the second output power generated by the compressed gas energy storage subsystem reaches a peak value of the rated output power, the valve of the water storage subsystem is closed.

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