A hybrid energy storage system and method for intelligent pumping and gravity power generation

Abstract

The application discloses a kind of intelligent pumping and gravity power generation hybrid energy storage systems, including intelligent pumping energy storage system and gravity power generation energy storage system two parts, two parts energy storage system are controlled by control system and work cooperatively;The intelligent pumping energy storage system, including mutually independent and mutually adjacent between the first reservoir and the second reservoir;The water level of the first reservoir is higher than the second reservoir, the bottom of second reservoir is lower than the water level of the first reservoir to ensure that there is enough power generation fall;The first reservoir is connected with the second reservoir by water pipeline;First water pump;First generator is located at the end of the water pipeline of second reservoir to realize hydroelectric power generation in peak electricity consumption period;The gravity power generation energy storage system includes a plurality of gravity blocks and the lifting equipment for controlling the up-and-down movement of gravity block, track system, second generator;The control system controls the intelligent pumping energy storage system and gravity power generation energy storage system, realizes the energy storage and power generation of two parts system.

Description

Technical Field

[0001] This invention belongs to the field of physical energy storage in power systems, and relates to a hybrid energy storage system and method based on intelligent pumping and gravity power generation in the natural environment. Background Technology

[0002] With the continuous advancement of new power system construction, the power system is characterized by a high proportion of renewable energy and a high proportion of power electronic equipment. However, renewable energy power generation technologies such as wind and solar power have drawbacks such as instability, randomness, and intermittency, making them prone to supply-demand mismatch problems. Specifically, wind power and solar power plants generate the most electricity in the early morning and at noon, respectively, while peak electricity consumption occurs at 10 am and 8 pm. There is a significant mismatch between the peak power generation periods and peak electricity consumption periods. This mismatch between peak power generation and peak electricity consumption results in the waste of excess electricity that cannot be used during peak power generation, while peak electricity consumption periods are precisely when power generation is not peak, leading to a situation where the grid load is high and the supply is insufficient. In addition, seasonal and weather factors will also increase the instability of renewable energy power generation. As the proportion of volatile and intermittent renewable energy in the power structure continues to increase, the supply side will also exhibit random fluctuations. Grid frequency control is becoming increasingly important, and the demand for peak shaving and frequency regulation is becoming more urgent. An effective way to solve this problem is to use power storage systems to store the large amount of surplus low-priced electricity during peak power generation periods. Power storage systems can be used to smooth the output of power generation and to smooth peak and valley loads, thereby balancing the grid load.

[0003] Electric energy storage encompasses various methods, including mechanical energy storage, electrochemical energy storage, electromagnetic energy storage, thermal energy storage, and chemical energy storage. Electrochemical energy storage most commonly utilizes a large number of batteries for charging and discharging. Mechanical energy storage includes common methods such as pumped hydro storage, gravity storage, and compressed air storage. Pumped hydro storage is a type of gravity storage, utilizing the surplus low-cost electricity from the grid during peak power generation to pump water to a higher reservoir (e.g., a mountaintop reservoir). During peak electricity demand, the water is then brought down to a generator for hydroelectric power generation, utilizing the water's potential energy. A common method of gravity storage involves using a lifting system to hoist a massive counterweight hundreds of meters or even higher during peak power generation. During peak demand, the counterweight is lowered, utilizing the potential energy conversion during its descent. A reduction gearbox controls the descent speed, connecting to a generator to produce electricity, thus achieving the conversion, storage, and release of surplus electrical energy. Existing energy storage power stations have many shortcomings: First, most existing energy storage power stations use a single energy storage method, which is not very efficient. Second, the construction of existing energy storage power stations requires huge investments in infrastructure, energy storage and power generation facilities, the energy storage benefits are not ideal, and the investment payback period is too long. Third, some energy storage power stations require a large amount of land resources, which has a great impact on the environment.

[0004] Therefore, a new type of large-capacity, high-efficiency, and low-cost power storage system is needed to overcome the shortcomings of the above-mentioned energy storage technologies, effectively ensure the stability and balance of the power system, smooth the output of power generation and peak shaving and valley filling, reduce the waste of power resources, and lower the production cost of power energy. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a hybrid energy storage system that combines pumped water storage and gravity power generation, which can operate independently or in conjunction with each other, and the system operation is more energy-efficient and efficient.

[0006] To address the aforementioned problems, the present invention provides a hybrid energy storage system combining intelligent pumped water storage and gravity power generation, comprising: an intelligent pumped water storage system and a gravity power generation energy storage system, wherein the two energy storage systems are controlled and coordinated by a control system; wherein:

[0007] The intelligent pumped storage system comprises a first reservoir and a second reservoir that are independent of each other but adjacent to each other; the water level of the first reservoir is higher than that of the second reservoir, and the bottom of the second reservoir is lower than that of the first reservoir to ensure sufficient head for power generation; the first reservoir and the second reservoir are connected by a water transmission pipeline.

[0008] The first water pump outputs water from the second reservoir to the first reservoir during off-peak electricity usage periods in order to free up storage space in the second reservoir.

[0009] The first generator is located at the end of the water transmission pipeline of the second reservoir, and uses the water level difference between the first and second reservoirs to generate hydropower during peak electricity demand periods.

[0010] The gravity power generation and energy storage system is located in the area of ​​the second reservoir and includes multiple gravity blocks, a track system for controlling the up and down movement of the gravity blocks, and a second generator.

[0011] During peak electricity consumption periods, when the water level of the second reservoir is low, the gravity block slowly descends along the track system under the action of gravity, releasing gravitational potential energy. The gravity block is connected to a deceleration system and a generator via steel cables, and the gravitational potential energy released by the descending gravity block drives the generator to generate electricity.

[0012] The control system controls the intelligent pumped water storage system and the gravity power generation storage system to realize energy storage and power generation of the two systems.

[0013] The peak and off-peak electricity consumption periods refer to the load status of the external public power grid; the peak electricity consumption period is the power generation phase of the energy storage system, and the off-peak electricity consumption period is the energy storage phase of the energy storage system.

[0014] A further improvement is that the first reservoir is a natural river channel, lake, or other natural body of water whose capacity can be considered as an infinite water resource, and the impact of water level fluctuations on the hybrid energy storage system can be ignored.

[0015] A further improvement is that the second reservoir is a mine pit, a lake, or other water-storing landform with a certain storage capacity; the second reservoir serves as the water storage facility for an intelligent pumped storage system.

[0016] A further improvement is that the water transmission pipeline between the first reservoir and the second reservoir is also equipped with a first electric gate valve, whose opening and closing are controlled by the control system.

[0017] A further improvement is that the impeller of the first generator is mounted on a retractable vertical drive shaft, which is installed inside a retractable telescopic pipe. The telescopic pipe is connected to the end of the water supply pipe, directing the water flow from the water supply pipe to the impeller of the first generator, driving the impeller to rotate and generate electricity. The retractable vertical drive shaft and the telescopic pipe are synchronously controlled by a lifting device to ensure that the relative position between the impeller and the telescopic pipe is fixed and the overall lifting is achieved, thus maximizing water flow utilization.

[0018] A further improvement is that a distance measuring device is installed at the end of the telescopic pipe. The distance measuring device measures the relative distance between the impeller and the water surface of the second reservoir. When the water level of the second reservoir changes, the impeller is always kept in the position with the most efficient water flow utilization.

[0019] A further improvement is that the gravity block has a hollow structure, forming a cavity with a certain capacity inside, which can be filled with water and drained using air pressure.

[0020] A further improvement is that the gravity block is a hollow box made of concrete or metal, or a solid box.

[0021] A further improvement is that when the gravity block is a hollow box, the internal cavity is connected to the outside through a second electric gate valve to allow air or water to enter or exit; the second electric gate valve is controlled by the control system.

[0022] A further improvement is that the second reservoir also includes a truss system above it, and the truss system is equipped with lifting equipment. The gravity block is connected to the lifting equipment via a track system, enabling the gravity block to rise and fall. The truss system spans over the second reservoir and its bank. The lifting equipment can suspend the gravity block and move it along the truss system, moving the gravity block to the area above the second reservoir and the gravity block storage area on the bank of the second reservoir. During peak electricity consumption periods, the gravity block can be moved to the top of the second reservoir and released to achieve gravity power generation.

[0023] A further improvement is that the gravity power generation and energy storage system also includes an air compressor and pipelines, with the pipelines connecting the air compressor to the cavity of the gravity block; the air compressor can generate high-pressure air to discharge the water in the cavity of the gravity block through the pipelines, thereby changing the buoyancy of the gravity block in the water.

[0024] The control method for energy storage using the above-mentioned hybrid energy storage system disclosed in this invention includes: the hybrid energy storage system comprises two parts, an intelligent pumped hydro energy storage system and a gravity power generation energy storage system, and the two parts of the energy storage system are jointly controlled by a control system.

[0025] The water level and bottom of the first reservoir are higher than those of the adjacent second reservoir;

[0026] During peak electricity consumption periods, i.e. when the hybrid energy storage system is in power generation mode;

[0027] The intelligent pumped storage system's control system opens an electric gate valve on the water supply pipeline connecting the first and second reservoirs. Water from the first reservoir flows through the pipeline into a telescopic pipe, driving a first generator to generate electricity before flowing into the second reservoir. During the power generation process, the water level in the second reservoir gradually rises. The impeller of the first generator is connected to the first generator via a telescopic vertical drive shaft. The impeller and vertical drive shaft are located inside the telescopic pipe. A distance measuring device is located at the end of the telescopic pipe. This device measures the height between the impeller of the first generator and the water surface of the second reservoir and transmits the data to the control system. The control system controls a lifting device to raise and lower the position of the telescopic pipe port and the impeller, ensuring that the end of the telescopic pipe and the position of the impeller move synchronously with the water surface of the second reservoir, maintaining a constant height difference to guarantee the highest gravity flow utilization efficiency.

[0028] The gravity power generation and energy storage system described above has a gravity block with an internal cavity. During peak electricity consumption periods, the gravity block is filled with water to store as much gravitational potential energy as possible. Initially, the gravity block gradually descends from its highest position along the gravity block track under the action of gravity. During the descent, the gravity block converts its gravitational potential energy into mechanical kinetic energy to drive a second generator through a steel cable and a deceleration system. The second generator then converts the mechanical kinetic energy into electrical energy.

[0029] During periods of low electricity demand, i.e. when the hybrid energy storage system is in energy storage mode:

[0030] At this time, the second reservoir is full of water. The first water pump pumps the water from the second reservoir back to the first reservoir through the water pipeline to free up the capacity of the second reservoir and prepare for the next power generation. The capacity of the first reservoir is considered to be infinite. During the process of the first water pump pumping water into the first reservoir, the water level of the first reservoir does not change or the change is negligible.

[0031] During the pumping process, the water level of the second reservoir gradually decreases. The ranging device, vertical lifting device and control system are also linked to ensure that the position of the first water pump is always below the waterline but not deeply buried at the bottom of the water, so as to shorten the pumping head of the first water pump as much as possible and reduce its own energy consumption during the energy storage process.

[0032] The gravity power generation and energy storage device described above has a gravity block connected to the outside world via a second electric gate valve. The water inside the cavity of the gravity block is gradually discharged by an air compressor, allowing the gravity block to gain buoyancy and gradually rise. When it rises to the water surface of the second reservoir, the lifting equipment intervenes and the cavity inside the gravity block is refilled with water. Once the cavity is full, the lifting equipment lifts the gravity block to a high altitude, thus achieving gravity energy storage.

[0033] A further improvement is characterized in that: the gravity power generation and energy storage system further includes a truss system, which spans above the second reservoir. A lifting device, located on the truss's guide rails, can suspend the gravity block for horizontal movement. During periods of low electricity demand, i.e., when the hybrid energy storage system is in its energy storage phase, the lifting device hoists the gravity block to a high altitude and transfers it horizontally along the truss system to a storage area located on the bank of the second reservoir. The terrain of the storage area has sufficient height to allow the gravity block to be in a gravity energy storage state, with its internal cavity filled with water. During periods of high electricity demand, the lifting device moves the gravity block above the second reservoir and slowly lowers it, initiating the power generation state of the gravity power generation and energy storage system.

[0034] A further improvement is that the intelligent pumped storage system and the gravity power generation storage system can independently complete the energy storage and power generation processes through the control system, and can also be coordinated and linked for control. When the hybrid energy storage system enters the power generation mode, the gravity power generation storage system can be activated first to generate electricity, so as to make full use of the maximum descent space of the gravity block formed by the low water level of the second reservoir. At the same time, when the hybrid energy storage system enters the energy storage mode, the second reservoir is at a high water level, and the gravity power generation storage system can be activated first, so that the gravity block can take advantage of the high water level of the second reservoir to rise to the highest possible height with full use of buoyancy, and then start the lifting equipment to save energy consumption.

[0035] A further improvement is that the gravity power generation and energy storage system can drive the second generator to generate electricity even when the gravity block is floating by switching the working mode of the deceleration mechanism connected to the gravity block.

[0036] A further improvement is that the internal cavity of the gravity block is connected to an external air compressor via a pipeline, and the second gate valve is controlled by the control system to fill and release water and air into the internal cavity of the gravity block.

[0037] This invention makes full use of existing natural resources, such as the first reservoir being a natural river channel and the second reservoir being a mine pit. The first and second reservoirs have an ideal drop, providing excellent natural conditions for gravity energy storage. This greatly reduces the capital investment in the construction of energy storage facilities and can also significantly shorten the construction cycle of energy storage facilities.

[0038] This invention combines pumped storage and gravity storage, greatly improving the efficiency of energy storage power generation. The gravity block moves to the surface of the second reservoir using buoyancy, reducing the power consumption of transporting the gravity block from the bottom of the second reservoir upwards.

[0039] The invention features an impeller of a first generator that can move synchronously with the water level changes of a second reservoir, thus maintaining maximum efficiency during power generation and maximum efficiency with optimal energy consumption during water pumping. Attached Figure Description

[0040] Figure 1 This is a schematic diagram of an energy storage power generation system that transfers water from the first reservoir to the second reservoir;

[0041] Figure 2 This is a schematic diagram of an energy storage power generation system that transfers water from the first reservoir to the second reservoir. Implementation

[0042] The following detailed description, in conjunction with the accompanying drawings, provides specific embodiments of the present invention and clearly and completely describes the technical solutions of the present invention. However, the present invention is not limited to the following embodiments. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. The advantages and features of the present invention will become clearer from the following description and claims. It should be noted that the accompanying drawings are all in a very simplified form and use non-precise ratios, and are only used for the purpose of conveniently and clearly illustrating the embodiments of the present invention. All other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0043] This invention can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, providing these embodiments will make the disclosure thorough and complete, and will fully convey the scope of the invention to those skilled in the art. In the drawings, for clarity, the dimensions and relative dimensions of layers and regions may be exaggerated, and the same reference numerals denote the same elements throughout. In the description of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0044] The present invention describes a hybrid energy storage system combining intelligent pumping and gravity power generation, such as... Figure 1 As shown, the hybrid energy storage system comprises two parts: an intelligent pumped hydro storage system and a gravity power generation energy storage system. These two energy storage systems are controlled and operate in coordination by a control system. Its structure mainly includes:

[0045] The intelligent pumped-storage energy system comprises a first reservoir and a second reservoir, which are independent yet adjacent to each other. The water level of the first reservoir is higher than that of the second reservoir, while the bottom of the second reservoir is lower than that of the first reservoir to ensure sufficient head for power generation. The first reservoir can be a natural river channel, a river, or a natural water resource with a near-infinite storage capacity (relative to the system of this invention). Its water level can be considered constant for this energy storage system. The second reservoir is a low-lying terrain adjacent to the first reservoir with a certain storage capacity and sufficient vertical head, such as a mine pit or natural cave. During the energy storage and power generation process of this system, its water level can exhibit significant and sufficiently high head variations. The first and second reservoirs are connected by a water pipeline, and the first reservoir is generally not far from the second reservoir. Such terrain is common in many parts of my country, and the second reservoir is usually close to a mountain or cliff, making it very suitable for conversion into the hybrid energy storage system of this invention.

[0046] The first reservoir is generally connected to the second reservoir through water pipelines or ditches. A first electric gate valve is installed on the water pipeline or ditch, which is controlled by a control system to realize the opening and closing of the water flow in the water pipeline.

[0047] The first water pump outputs water from the second reservoir to the first reservoir during off-peak electricity demand periods. This utilizes the cheap and surplus electricity available on the public power grid during these off-peak periods to free up storage space in the second reservoir, thus achieving hydroelectric energy storage.

[0048] The first generator is located at the end of the water pipeline to the second reservoir. It utilizes the water level difference between the first and second reservoirs to generate hydroelectric power during peak electricity demand periods. The peak or off-peak electricity demand periods referred to in this invention refer to the load status of the external public power grid. During peak electricity demand periods, this energy storage system generates electricity and sells it to the public grid. Off-peak electricity demand periods are the energy storage phase of this invention, utilizing surplus electricity from the external public grid for energy storage. Since the electricity price on the external public grid differs between peak and off-peak periods, this energy storage system can realize economic value. A substation system, such as a transformer, is also connected to the external public grid after the first generator. This is known technology and is beyond the scope of this invention, so it will not be described further.

[0049] The first generator is a hydroelectric generator, with its impeller connected via a retractable vertical drive shaft. Both the impeller and the vertical drive shaft are housed within a telescopic pipe, such as a corrugated pipe or a similar structure, that can extend and retract vertically. The impeller, vertical drive shaft, and telescopic pipe can move synchronously up and down via a lifting system. The telescopic pipe connects to a water supply pipeline between the first and second reservoirs. Water from the first reservoir flows through the pipeline and then into the downward-moving telescopic pipe, ultimately driving the impeller at its end to rotate. This rotation is then connected to the first generator via the vertical drive shaft, causing the first generator to generate electricity. The water then flows into the second reservoir. A distance measuring device continuously monitors the distance between the impeller and the telescopic pipe and the water surface of the second reservoir, ensuring the impeller remains above the water surface. This reduces impeller operating resistance while maximizing the water flow drop and utilizing hydraulic potential energy. The opening of the telescopic pipe is also always located at the impeller position to ensure the water flow propels the impeller as much as possible.

[0050] The ranging device and lifting system also monitor the position of the first water pump, ensuring that the first water pump remains below the water surface and maintains a low head when the water level changes, thus saving power consumption during energy storage.

[0051] The gravity power generation and energy storage system is located within the area of ​​the second reservoir and includes multiple gravity blocks, a track system for controlling the up-and-down movement of the gravity blocks, and a second generator.

[0052] During peak electricity consumption periods, when the water level in the second reservoir is low, the gravity block slowly descends along the track system under the influence of gravity, releasing gravitational potential energy. The track system can be a vertical gantry or steel rails, or it can be directly made of steel cables. The gravity block is connected to a deceleration system and a generator via steel cables, and the gravitational potential energy released by the descending gravity block drives the generator to generate electricity.

[0053] The gravity block is a hollow or solid box made of concrete or metal. To maximize the operating efficiency of this hybrid energy storage system, the invention employs a hollow box structure, forming an internal cavity with a certain capacity. This internal cavity can be filled with water and drained using air pressure. The connection between the internal cavity and the external environment is controlled by a second electric gate valve.

[0054] The control system controls the intelligent pumped water storage system and the gravity power generation storage system, including controlling subsystems such as the ranging device, the first electric gate valve, the lifting system, the hoisting equipment, and the deceleration system, to realize energy storage and power generation of the two systems.

[0055] The second reservoir may also include a truss system, which is equipped with lifting equipment. The gravity block is connected to the lifting equipment via a track system, enabling the gravity block to rise and fall. The truss system spans over the second reservoir and its bank. The lifting equipment can suspend the gravity block and move it along the truss system, moving the gravity block to the area above the second reservoir and the gravity block storage area on the bank of the second reservoir. During peak electricity consumption periods, the gravity block can be moved to the top of the second reservoir and released to achieve gravity power generation.

[0056] The gravity power generation and energy storage system also includes an air compressor and pipelines. The pipelines connect the air compressor to the cavity of the gravity block. The air compressor generates high-pressure air and discharges the water in the cavity of the gravity block through the pipelines, thereby changing the buoyancy of the gravity block in the water.

[0057] The present invention discloses a control method for energy storage using the above-mentioned hybrid energy storage system, comprising: the hybrid energy storage system includes two parts, an intelligent pumped hydro energy storage system and a gravity power generation energy storage system, and the two energy storage systems can operate independently or in concert under the control of the control system, thereby achieving higher operating efficiency and greater economic benefits.

[0058] The water level of the first reservoir is much higher than that of the adjacent second reservoir, ensuring sufficient head for hydroelectric power generation.

[0059] During peak electricity consumption periods, i.e. when the hybrid energy storage system of this invention is in power generation operation:

[0060] like Figure 1 As shown, at this time, the water level of the second reservoir is at a low level. The intelligent pumped storage system controls the opening of the electric gate valve of the water conveyance pipeline connecting the first and second reservoirs. Water from the first reservoir enters the telescopic pipe through the water conveyance pipeline, driving the first generator to generate electricity and then flowing into the second reservoir. During the power generation process, the water level of the second reservoir gradually rises. The impeller of the first generator is connected to the first generator through a telescopic vertical drive shaft. The impeller and the vertical drive shaft are located inside the telescopic pipe. A distance measuring device is located at the end of the telescopic pipe. The distance measuring device measures the height between the impeller of the first generator and the water surface of the second reservoir and transmits the data to the control system. The control system controls the lifting device to raise and lower the position of the telescopic pipe port and the impeller, so that the position of the end of the telescopic pipe and the impeller moves synchronously with the water surface of the second reservoir, and the height difference remains constant to ensure the highest gravity water flow utilization efficiency.

[0061] The gravity-powered energy storage system described above uses a gravity block with an internal cavity. During peak electricity demand, the block is filled with water to maximize gravitational potential energy storage. Initially, it descends gradually from its highest position along a gravity block track under the influence of gravity. During the descent, the gravity block converts its gravitational potential energy into mechanical kinetic energy to drive a second generator via steel cables and a deceleration system. This second generator then converts the descent speed into electrical energy. The descent speed can be precisely controlled using a corresponding control algorithm based on the weight of the gravity block and the deceleration ratio of the deceleration structure. The power generation can also be adjusted.

[0062] During periods of low electricity demand, i.e. when the hybrid energy storage system is in the energy storage operation phase:

[0063] like Figure 2 As shown, the second reservoir is currently full. The first water pump draws water from the second reservoir back to the first reservoir via a pipeline to free up storage capacity in the second reservoir, thus achieving hydroelectric energy storage and preparing for the next power generation. Since the first reservoir is a natural river channel, its capacity is considered infinite. During the pumping process, the water level in the first reservoir remains unchanged or changes negligible for the hybrid energy storage system of this invention.

[0064] During the pumping process, the water level of the second reservoir gradually decreases. The ranging device, vertical lifting device, and control system are also linked to ensure that the position of the first water pump is always below the waterline but not deeply buried at the bottom of the water, so as to shorten the pumping head of the first water pump as much as possible and reduce its own energy consumption during the energy storage process.

[0065] The gravity power generation and energy storage device described above has a gravity block connected to the outside world via a second electric gate valve. The water inside the cavity of the gravity block is gradually discharged by an air compressor, allowing the gravity block to gain buoyancy and gradually rise. When it rises to the water surface of the second reservoir, the lifting equipment intervenes and the cavity inside the gravity block is refilled with water. Once the cavity is full, the lifting equipment lifts the gravity block to a high altitude, thus achieving gravity energy storage.

[0066] The gravity power generation and energy storage system also includes a truss system spanning above the second reservoir, which can be constructed using the mountainside adjacent to the reservoir. A lifting device, positioned on the truss's guide rails, can suspend the gravity blocks for horizontal movement. During off-peak electricity demand, i.e., when the hybrid energy storage system is in its energy storage phase, the lifting device hoists the gravity blocks to a high altitude and transfers them horizontally along the truss system to a storage area located on the bank of the second reservoir. The terrain of the storage area is high enough to allow the gravity blocks, with their internal cavities filled with water, to be in a gravity energy storage state. During peak electricity demand, the lifting device moves the gravity blocks along the truss system above the second reservoir and slowly lowers them, initiating the power generation phase of the gravity power generation and energy storage system.

[0067] The above control method is the control method under normal working conditions. The intelligent pumped hydro storage system and the gravity power generation storage system can independently complete the energy storage and power generation processes through the control system. In order to operate the system more efficiently, the hybrid energy storage system of the present invention can also perform the following coordinated control:

[0068] When the hybrid energy storage system enters power generation mode, the gravity power generation and storage system can be prioritized for power generation. Since the second reservoir is at its lowest water level at this time, prioritizing gravity power generation fully utilizes the maximum descent space of the gravity block created by the low water level in the second reservoir. Because when the water level is high, even if the gravity block is fully loaded with water, it will still be affected by buoyancy, and some of the stored gravitational potential energy will be wasted due to buoyancy. Simultaneously, when the hybrid energy storage system enters energy storage mode, the second reservoir is at a high water level, allowing the gravity power generation and storage system to be prioritized. This enables the gravity block to utilize the high water level of the second reservoir, fully leveraging buoyancy to rise to the maximum possible height before starting the lifting equipment to save energy. Furthermore, this invention can also achieve the following: by switching the operating mode of the deceleration mechanism connected to the gravity block, buoyancy can be utilized during the gravity block's ascent to drive the second generator for power generation.

[0069] Furthermore, the internal cavity of the gravity block is connected to an external air compressor via a pipe. The second gate valve is controlled by the control system to fill and release water and air into the internal cavity of the gravity block. When the internal cavity of the gravity block is full of water, high-pressure air can be injected into the internal cavity by the air compressor to discharge the water. Of course, based on the flexibility of the hybrid energy storage system of the present invention, when the system is in power generation mode and the gravity power generation system is used first, the gravity block descends to its lowest point. At this time, the water level of the second reservoir is still lower than that of the gravity block. In this case, there is no need to use the air compressor; simply opening the second electric gate valve allows the water stored in the internal cavity of the gravity block to flow out naturally.

[0070] As an example, the calculation of energy storage power consumption and power generation of the hybrid energy storage system of the present invention is explained as follows, assuming:

[0071] A. The first reservoir is a river channel: the river flow is not considered for the time being, and is assumed to be large enough.

[0072] B. Dimensions of the second reservoir: L*W*H: 200X100X100 (unit: meters); Capacity of the second reservoir: V=2*10 ^6 (Unit: m³)

[0073] C. The period of low electricity price is T1=10 hours, but this calculation is based on T1=8 hours.

[0074] D. The peak electricity price period is T3=4 hours, and this calculation is based on T3=4 hours.

[0075] Calculation of hydroelectric power generation:

[0076] P_turbine = 9.8 * QH / n (KJ) = 9.8 * 138.89 * 50 / 90% = 75617 KW.

[0077] In the above formula:

[0078] Q = 500000 / 3600 = 138.89 m³ / s power generation flow rate, m 3 / s.

[0079] P represents the power output of the water turbine (unit: KW).

[0080] Q is the velocity of the water in the turbine (unit: m³ / s).

[0081] H represents the hydroelectric head (0-100 meters, with an average of 50 meters) (unit: meters).

[0082] The power generation time is the peak electricity price period (unit: seconds).

[0083] n generator set efficiency.

[0084] The actual daily power generation is:

[0085] W_total = P_water * T_3 = 75617 * 4 kWh = 302471 kWh

[0086] Calculation of power consumption for water pumping:

[0087] P_pump = Q*H / 367 / η = 250000*50 / 367 / 80% = 42575KW.

[0088] η — Unit efficiency is calculated as 80%.

[0089] Q—flow rate in cubic meters per hour (2000000 / 8) = 250000 cubic meters per hour.

[0090] H—Head in meters (average head 50 meters).

[0091] P-pump — Input power (KW).

[0092] The actual daily power consumption for pumping water is:

[0093] W_pump = P_pump * T = 42575 * 8 = 340600 degrees.

[0094] The daily energy consumption difference for pumped hydro power generation is:

[0095] Wdifference = Wtotal - Wpump = 302471 - 340600 = -38129 degrees.

[0096] Calculation of power generation from gravity energy storage (single energy storage block) (calculation without considering water resistance), as an example, assuming:

[0097] A. Material of the gravity block: marble, density: 2.6~2.8T / m³, based on 2.6T / m³.

[0098] B. Dimensions of the gravity block (length * width * height): 3 * 3 * 2 (unit: meters).

[0099] C. Dimensions of the gravity block cavity (length * width * height): 2.4 * 2.4 * 1.4 (unit: meters).

[0100] D. Air quality: Negligible.

[0101] The mass of the marble: M_stone = (3*3*2 - 2.4*2.4*1.4)*2.6 = 9.936*2.6 = 25.8336T.

[0102] The mass of water filling the cavity is: M_water = 2.4 * 2.4 * 1.4 = 8.064 T.

[0103] Mass of the cavity after filling with water: M_filled with water = M_stone + M_water = 25.8336 + 8.064 = 33.8976T.

[0104] The volume of the hollow airbag is: V_bag = 25.8336 - 8.064 = 17.7696 m³. An 18 m³ airbag needs to be selected.

[0105] The amount of electricity generated by gravitational potential energy is:

[0106] Ep = MgH = 33.8976 * 1000 * 10 * 100 = 33.8976 * Joules / 3.6 = 9.416 degrees Celsius

[0107] The electrical energy required for inflation at a depth of 100 meters is:

[0108] E_air = PV = 1 * J = / (3.6X) kWh = 0.278 kWh of electricity.

[0109] The power consumption of the air compressor is:

[0110] W_air = 0.278 / 0.9 = 0.31 kWh of electricity.

[0111] Inflating to 26 cubic meters requires the following amount of electricity:

[0112] Total gas consumption = 0.31 * 26 = 8.06 kWh of electricity.

[0113] The energy required to pump water out of the gravity block cavity is:

[0114] W_pumping = MgH / η = 8.086 * 1000 * 10 * 100 / 0.8 = 1.01 * J = 2.8 kWh

[0115] Therefore, the total power consumption in one cycle is:

[0116] W_total = E_air + W_total = 8.06 + 2.8 = 10.06 kWh of electricity.

[0117] The energy consumption difference for gravity power generation is:

[0118] Edifference = Ep - Wtotal = -0.644 degrees.

[0119] The above are merely preferred embodiments of the present invention and are not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A hybrid energy storage system combining intelligent pumping and gravity power generation, characterized in that: The hybrid energy storage system comprises two parts: a smart pumped hydro storage system and a gravity power generation energy storage system. These two systems are controlled and operate in coordination by a control system. The intelligent pumped storage system comprises a first reservoir and a second reservoir that are independent of each other but adjacent to each other; the water level of the first reservoir is higher than that of the second reservoir, and the bottom of the second reservoir is lower than that of the first reservoir to ensure sufficient head for power generation; the first reservoir and the second reservoir are connected by a water transmission pipeline. The first water pump outputs water from the second reservoir to the first reservoir during off-peak electricity usage periods in order to free up storage space in the second reservoir. The first generator is located at the end of the water transmission pipeline of the second reservoir, and uses the water level difference between the first and second reservoirs to generate hydropower during peak electricity demand periods. The gravity power generation and energy storage system is located in the area of ​​the second reservoir and includes multiple gravity blocks, lifting equipment and track system for controlling the up and down movement of the gravity blocks, as well as a second generator. During peak electricity consumption periods, when the water level of the second reservoir is low, the gravity block slowly descends along the track system under the action of gravity, releasing gravitational potential energy. The gravity block is connected to a deceleration system and a generator via steel cables, and the gravitational potential energy released by the descending gravity block drives the generator to generate electricity. The control system controls the intelligent pumped water storage system and the gravity power generation storage system to realize energy storage and power generation of the two systems. The peak and off-peak electricity consumption periods refer to the load status of the external public power grid; the peak electricity consumption period is the power generation phase of the energy storage system, and the off-peak electricity consumption period is the energy storage phase of the energy storage system. The second reservoir also includes a truss system above it, which is equipped with lifting equipment. The gravity blocks are connected to the lifting equipment via a track system, enabling the gravity blocks to rise and fall. The truss system spans over the second reservoir and its banks. The lifting equipment can suspend the gravity blocks and move them along the truss system, moving them to the gravity block storage area above the second reservoir and on its banks. During peak electricity consumption periods, the gravity blocks can be moved to the top of the second reservoir and released to achieve gravity power generation.

2. The hybrid energy storage system of intelligent pumping and gravity power generation as described in claim 1, characterized in that: The first reservoir is a natural river, lake, or other natural water resource with an unlimited capacity, and the impact of water level changes on the hybrid energy storage system is negligible.

3. The hybrid energy storage system of intelligent pumping and gravity power generation as described in claim 2, characterized in that: The second reservoir is a mine pit, lake, or other water-storing landform with a certain storage capacity; the second reservoir serves as the water storage facility for an intelligent pumped storage system.

4. The hybrid energy storage system of intelligent pumping and gravity power generation as described in claim 1, characterized in that: The water transmission pipeline between the first reservoir and the second reservoir is also equipped with a first electric gate valve, whose opening and closing are controlled by the control system.

5. The hybrid energy storage system of intelligent pumping and gravity power generation as described in claim 1, characterized in that: The impeller of the first generator is mounted on a retractable vertical drive shaft, which is installed inside a retractable telescopic tube. The telescopic tube is connected to the end of the water supply pipe, which directs the water flow from the water supply pipe to the impeller of the first generator, driving the impeller to rotate and generate electricity. The retractable vertical drive shaft and the telescopic tube are synchronously controlled by a lifting device to ensure that the relative position between the impeller and the telescopic tube is fixed and the overall lifting is achieved, thus maximizing water flow utilization.

6. The hybrid energy storage system of intelligent pumping and gravity power generation as described in claim 5, characterized in that: The telescopic pipe is equipped with a distance measuring device at its end. The distance measuring device measures the relative distance between the impeller and the water surface of the second reservoir. When the water level of the second reservoir changes, the impeller is always kept in the position with the most efficient water flow utilization.

7. The hybrid energy storage system of intelligent pumping and gravity power generation as described in claim 1, characterized in that: The gravity block is a hollow structure, with an internal cavity of a certain capacity, which can be filled with water and drained using air pressure.

8. The hybrid energy storage system of intelligent pumping and gravity power generation as described in claim 1, characterized in that: The gravity block is a hollow box made of concrete or metal, or a solid box.

9. The hybrid energy storage system of intelligent pumping and gravity power generation as described in claim 8, characterized in that: When the gravity block is a hollow box, the internal cavity is connected to the outside through a second electric gate valve to allow air or water to enter or exit; the second electric gate valve is controlled by the control system.

10. The control method for the hybrid energy storage system of intelligent pumped water and gravity power generation as described in claim 1: characterized in that: The track system can be a gantry or a vertically erected steel rail, or a steel cable directly connected to the hoisting system of the lifting equipment.

11. The hybrid energy storage system of intelligent pumping and gravity power generation as described in claim 7, characterized in that: The gravity power generation and energy storage system also includes an air compressor and pipelines. The pipelines connect the air compressor to the cavity of the gravity block. The air compressor generates high-pressure air and discharges the water in the cavity of the gravity block through the pipelines, thereby changing the buoyancy of the gravity block in the water.

12. A control method for controlling a hybrid energy storage system of intelligent pumped water and gravity power generation as described in claim 1, characterized in that: The hybrid energy storage system comprises two parts: an intelligent pumped hydro storage system and a gravity power generation energy storage system, and the two parts are jointly controlled by a control system. The water level and bottom of the first reservoir are higher than those of the adjacent second reservoir; During peak electricity consumption periods, i.e. when the hybrid energy storage system is in power generation mode; The intelligent pumped storage system's control system opens an electric gate valve on the water supply pipeline connecting the first and second reservoirs. Water from the first reservoir flows through the pipeline into a telescopic pipe, driving a first generator to generate electricity before flowing into the second reservoir. During the power generation process, the water level in the second reservoir gradually rises. The impeller of the first generator is connected to the first generator via a telescopic vertical drive shaft. The impeller and vertical drive shaft are located inside the telescopic pipe. A distance measuring device is located at the end of the telescopic pipe. This device measures the height between the impeller of the first generator and the water surface of the second reservoir and transmits the data to the control system. The control system controls a lifting device to raise and lower the position of the telescopic pipe port and the impeller, ensuring that the end of the telescopic pipe and the position of the impeller move synchronously with the water surface of the second reservoir, maintaining a constant height difference to guarantee the highest gravity flow utilization efficiency. The gravity power generation and energy storage system described above has a gravity block with an internal cavity. During peak electricity consumption periods, the gravity block is filled with water to store as much gravitational potential energy as possible. Initially, the gravity block gradually descends from its highest position along the gravity block track under the action of gravity. During the descent, the gravity block converts its gravitational potential energy into mechanical kinetic energy to drive a second generator through a steel cable and a deceleration system. The second generator then converts the mechanical kinetic energy into electrical energy. During periods of low electricity demand, i.e. when the hybrid energy storage system is in energy storage mode: At this time, the second reservoir is full of water. The first water pump pumps the water from the second reservoir back to the first reservoir through the water pipeline to free up the capacity of the second reservoir and prepare for the next power generation. The capacity of the first reservoir is considered to be infinite. During the process of the first water pump pumping water to the first reservoir, the water level of the first reservoir does not change or changes negligibly. During the pumping process, the water level of the second reservoir gradually decreases. The ranging device, vertical lifting device and control system are also linked to ensure that the position of the first water pump is always below the waterline but not deeply buried at the bottom of the water, so as to minimize the pumping head of the first water pump and reduce its own energy consumption during the energy storage process. The gravity power generation and energy storage device described above connects the gravity block to the outside world via a second electric gate valve. The water inside the cavity of the gravity block is gradually discharged by an air compressor, allowing the gravity block to gain buoyancy and gradually rise. When it rises to the water surface of the second reservoir, the lifting equipment intervenes and the cavity inside the gravity block is refilled with water. Once the cavity is full, the lifting equipment lifts the gravity block to a high altitude, thus achieving gravity energy storage.

13. The control method for the hybrid energy storage system of intelligent pumped water and gravity power generation as described in claim 12: characterized in that: The gravity power generation and energy storage system also includes a truss system spanning above the second reservoir. A lifting device, positioned on the truss's guide rails, can suspend the gravity block for horizontal movement. During off-peak electricity demand, i.e., when the hybrid energy storage system is in its energy storage phase, the lifting device hoists the gravity block to a high altitude and transfers it horizontally along the truss system to a storage area located on the bank of the second reservoir. The storage area has sufficient elevation to allow the gravity block to be in a gravity energy storage state, with its internal cavity filled with water. During peak electricity demand, the lifting device moves the gravity block above the second reservoir and slowly lowers it, initiating the power generation state of the gravity power generation and energy storage system.

14. The control method for the hybrid energy storage system of intelligent pumped water and gravity power generation as described in claim 12: characterized in that: The intelligent pumped-storage system and the gravity power generation system can independently complete the energy storage and power generation processes through the control system, and can also be coordinated and linked for control. When the hybrid energy storage system enters the power generation mode, the gravity power generation system is activated first to generate electricity, so as to make full use of the maximum descent space of the gravity block formed by the low water level of the second reservoir. At the same time, when the hybrid energy storage system enters the energy storage mode, the second reservoir is at a high water level, and the gravity power generation system is activated first, so that the gravity block can take advantage of the high water level of the second reservoir to rise to the maximum height with full use of buoyancy, and then start the lifting equipment to save energy consumption.

15. The control method for the hybrid energy storage system of intelligent pumped water and gravity power generation as described in claim 12: characterized in that: The gravity power generation and energy storage system described above can drive the second generator to generate electricity while the gravity block is floating by switching the working mode of the deceleration mechanism connected to the gravity block.

16. The control method for the hybrid energy storage system of intelligent pumped water and gravity power generation as described in claim 12: characterized in that: The internal cavity of the gravity block is connected to an external air compressor via a pipeline. The second electric gate valve is controlled by the control system to fill and release water and air into the internal cavity of the gravity block.

17. The control method for the hybrid energy storage system of intelligent pumped water and gravity power generation as described in claim 12: characterized in that: When the gravity block reaches its lowest point after power generation, it opens the second electric gate valve, allowing the water stored in its internal cavity to flow out naturally into the second reservoir.

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