Reservoir-based power-variable gravity energy storage device and flood discharge collaborative complementation method

Abstract

The invention discloses a reservoir-based power-variable gravity energy storage device and flood discharge cooperative complementation method, and belongs to the technical field of hydraulic engineering and energy storage. The device is composed of a foldable flexible water bag, a winch-power generation all-in-one machine, a movable platform and a central intelligent control system; the water bag realizes'zero pump consumption energy charging 'and mass adjustment through a top back pressure valve and a bottom electric control valve; according to the system, by means of mass-speed double-closed-loop cooperative control, continuous, smooth, accurate and adjustable power generation power is achieved by dynamically adjusting the mass and the lowering speed of a water bag during discharging; meanwhile, through linkage with a reservoir SCADA system, virtual reservoir capacity can be created in the flood season to participate in peak clipping flood control, discharging is conducted according to the electricity price of the market after the flood peak, abandoned water resources are converted into high-price electric energy, and deep cooperation of flood control safety, power grid frequency modulation and economic benefits is achieved.

Description

Technical Field

[0001] This invention relates to the fields of water conservancy engineering and energy storage technology, and in particular to a reservoir-based variable power gravity energy storage device and a flood discharge coordination and complementarity method. Background Technology

[0002] Currently, the comprehensive and efficient utilization of hydropower resources, especially in the field of reservoir operation, faces two major challenges: on the one hand, the power grid's requirements for the speed, accuracy, and continuity of power regulation resources are increasing; on the other hand, reservoir flood control scheduling often leads to a large amount of hydropower being wasted in the form of "water abandonment." How to organically combine these two aspects to achieve a balance between safety, economy, and efficiency has become an urgent technical problem to be solved.

[0003] To address these issues, various technological approaches have emerged within the industry. The main implementation methods include: 1) Land-based tower gravity storage, which involves constructing a high tower downstream of the dam and using a motor-driven hoisting system to lift / lower concrete blocks for storage / discharge; 2) Mountain slope track gravity storage, which utilizes a spoil heap to lay tracks and uses containerized concrete blocks as the energy storage medium; 3) Conventional pumped storage, which involves constructing a lower reservoir and reversible generating units; and 4) Fixed-mass floating gravity storage, which involves suspending a constant-mass steel drum on a floating platform and generating electricity using changes in water level.

[0004] However, all of the aforementioned existing technologies have significant limitations. First, gravity energy storage solutions relying on tiered concrete blocks (such as tower or track-mounted systems) exhibit stepped power output variations, failing to achieve continuous and smooth power regulation. Furthermore, the time required for hoisting a single block is long, resulting in slow power response and difficulty in meeting the grid's second-level frequency regulation requirements. Second, these solutions typically require large amounts of permanent land, often lacking suitable construction sites downstream of reservoirs with complex terrain. Third, while fixed-mass floating solutions do not occupy land, their power passively fluctuates with water level, decreasing as the effective head decreases, making energy storage uncontrollable. Additionally, while pumped storage offers continuous power regulation, it heavily relies on specific terrain conditions (requiring downstream depressions), and its scheduling is often disconnected from flood control systems, leading to low energy recovery rates. A common key flaw of all existing technologies is that they treat "flood discharge" and "energy storage" as two independent processes, failing to directly utilize the reservoir's own water pressure for "zero-energy" charging; the energy storage process still requires additional primary energy consumption.

[0005] In summary, existing technologies cannot simultaneously solve the three core problems of traditional gravity energy storage: stepped power regulation, large permanent land requirements, and disconnection from reservoir flood discharge operations. Therefore, there is an urgent need for a new technological solution that can achieve continuous, rapid, and precise energy storage regulation while seamlessly integrating into the reservoir's flood control and dispatching system without requiring additional permanent land, thus achieving a win-win situation for flood control safety, grid frequency regulation, and economic benefits. Summary of the Invention

[0006] The present invention aims to overcome the shortcomings of the prior art and provides a method for the coordinated and complementary use of a reservoir-based variable power gravity energy storage device and flood discharge, so as to simultaneously improve the frequency regulation capability of the power grid, the flood control safety of the reservoir, and the economic benefits of operation.

[0007] To achieve the above objectives, the present invention employs the following technical solution: On one hand, the present invention provides a reservoir-based variable power gravity energy storage device, the device comprising a foldable flexible water bag, a winch-generator integrated unit, a mobile platform, and a central intelligent control system, wherein: The foldable flexible water bag is equipped with a back pressure inlet valve at the top and an electrically controlled drain valve at the bottom. The winch-generator integrated machine is connected to the water bag and can switch between electric motor mode and generator mode; The mobile platform is used to carry the water bag and the winch-generator integrated machine. The mobile platform is either floating or shore-rail type and can automatically or controllably adjust its working position according to water level changes. The central intelligent control system is connected to the reservoir SCADA system, the power grid dispatching system, and the power market platform to perform global status perception, quality-velocity dual closed-loop collaborative control, and flood discharge collaborative decision-making.

[0008] Furthermore, the foldable flexible water bag is made of high-strength waterproof fabric, and its folding structure allows for compressed storage to save space when not in use.

[0009] Furthermore, the hoist-generator is equipped with a high-precision torque sensor and speed encoder, enabling it to respond to real-time commands for speed, torque, and power.

[0010] Furthermore, the central intelligent control system also includes a data fusion module, an adaptive positioning module, and a mass-velocity dual closed-loop control module, wherein: The data fusion module is used to collect real-time data on reservoir water conditions, power grid frequency regulation commands, electricity market prices, and equipment status. The adaptive positioning module plans and drives the mobile platform to the optimal working position based on the current water level. The mass-speed dual closed-loop control module is configured to control the drainage volume by adjusting the opening of the electrically controlled drain valve at the bottom of the water bag, and dynamically calculate the lowering speed of the winch-generator integrated machine based on the real-time total mass data of the water bag, so as to achieve continuous, smooth and adjustable power generation.

[0011] Furthermore, the mass-velocity dual closed-loop control module also includes a mass decrease control loop, a speed regulation control loop, and a coupling feedback unit, wherein: The mass reduction control loop uses a preset mass reduction curve as a set value and adjusts the opening of the electrically controlled drain valve to make the total mass of the water bag decrease according to the curve. The speed regulation control loop is configured to operate according to physical formulas. Real-time calculation of target drop speed And control the hoist-generator to operate at this speed, wherein, Indicates power generation capacity. This indicates the real-time total mass of the water bag. Represents gravitational acceleration. This indicates the speed at which the water bag is lowered. Indicates the overall system efficiency; The coupling feedback unit directly uses the real-time data from the mass sensor to determine the target lowering speed. The correction ensures that the power output of the generator is precisely matched with the grid command.

[0012] On the other hand, the present invention also provides a variable power gravity energy storage device based on a reservoir, as described above. The method applied to the variable power gravity energy storage device based on a reservoir as described above includes the following steps: Step 1, Global Status Awareness and Platform Deployment: The central controller integrates reservoir water conditions, power grid demand, and market signals in real time to plan and drive the mobile platform to the optimal operating location; Step 2, “Zero Pump Consumption Energy Recharge” and Mass Setting: By opening the back pressure inlet valve at the top of the water bag, water is automatically pumped to the target mass using the reservoir water pressure. The winch-generator unit then uses an electric motor to increase the potential energy stored in the water bag. Step 3, Continuously Adjustable Power Release: Based on the target discharge power curve, dynamic matching between the decrease in water bag mass and the lowering speed is achieved through mass-velocity dual closed-loop coordinated control, ensuring smooth power output; wherein, the target lowering speed... According to the formula Real-time calculation, For power generation capacity, The total mass of the water bag in real time. It is the acceleration due to gravity. For overall system efficiency; Step 4, Flood Discharge Coordination Decision: Based on the digital twin model, a coordinated scheduling plan that takes into account flood control safety, economic benefits and equipment lifespan is generated, and proactive peak shaving operations are performed when the inflow is close to the flood limit.

[0013] Furthermore, the "mass-velocity dual closed-loop coordinated control" in step three further includes: Mass reduction control: The drainage volume is precisely controlled by adjusting the opening of the electrically controlled drain valve, so that the total mass of the water bag decreases according to the preset curve; Dynamic velocity calculation: based on real-time mass data, using physical formulas Calculate the target drop speed; Coupling feedback: Mass sensor data is directly used for velocity target correction, forming a strongly coupled closed loop to suppress power fluctuations.

[0014] Furthermore, the flood discharge coordination decision-making in step four further includes: Long-term forecasting optimization: Using either graph neural networks or reinforcement learning algorithms, simulate the impact of different scheduling strategies on flood control indicators, power plant revenue, and equipment losses within a predetermined future time period. Real-time linkage control: When the inflow exceeds the limit, multiple sets of water bags are simultaneously raised to create "virtual storage capacity" and linked with the flood discharge gate system to ensure safe avoidance; Value recovery: After the flood control pressure is relieved, the discharge plan is optimized based on the real-time electricity price signal to convert the stored flood potential energy into high-priced electricity.

[0015] Furthermore, the mobile platform includes a floating platform with an anchor propulsion system and a fixed track platform with a drive trolley. The anchor propulsion system includes an electric propeller and an anchor chain tension adjustment device, which can automatically adjust the anchor position according to changes in water level. The central intelligent control system also includes a fault diagnosis and adaptive operation and maintenance module, used for real-time monitoring of equipment status, execution of safe shutdown strategies, and predictive maintenance; specifically including: operational safety monitoring: stress and strain sensors monitor changes in the water bag in real time; if abnormal stress concentration occurs, the controller can locally reduce the load or stop the operation of the water bag. The platform stability monitoring system adjusts the anchor chain tension or counterweight in real time to prevent overturning when the mass changes rapidly; adaptive fault handling: in the event of power grid failure, communication interruption, or equipment malfunction, the controller can execute preset emergency shutdown strategies and report maintenance requests.

[0016] Compared with the prior art, the present invention has the following advantages: Achieving continuous, smooth, and precise power regulation: The core "mass-velocity dual closed-loop coordinated control" technology overcomes the shortcomings of traditional gravity energy storage's step-output power, enabling the device to precisely track grid AGC commands like a high-quality frequency regulation resource, meeting high-standard frequency regulation requirements. Significantly improved energy efficiency and reduced operating costs: Utilizing the reservoir's natural water pressure to automatically fill water bags with "zero-pump energy consumption charging" eliminates energy conversion losses in the charging process of traditional energy storage methods, improving the overall cycle efficiency and economy of the system. Completely eliminating site limitations, flexible and environmentally friendly deployment: Adopting a platform design that can move along the water surface or reservoir bank, eliminating the need to acquire permanent downstream land, solving the core pain point of lack of construction sites in complex terrain reservoirs. High system modularity, short construction cycle, and minimal environmental disturbance. Innovative deep synergy between flood control and energy storage: Through deep linkage between the control system and the reservoir's SCADA system, the energy storage device is transformed into the reservoir's "virtual flexible capacity." Actively participating in peak shaving during flood control enhances the reservoir's flood safety margin and simultaneously converts some "abandoned water" into resources, realizing a paradigm shift from "passive flood control" to "active regulation + resource utilization." Improving overall economic benefits and system intelligence: The introduction of digital twins and AI scheduling enables proactive optimization of operational strategies, balancing flood control safety, equipment lifespan, and electricity market revenue, transforming the reservoir from a single water conservancy facility into a smart, multi-functional integrated energy node.

[0017] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures pointed out in the description, claims and drawings. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of a reservoir-based variable power gravity energy storage device according to one embodiment of the present invention. Figure 2 This is a schematic diagram of a method for coordinated and complementary power-variable gravity energy storage and flood discharge based on a reservoir, according to one embodiment of the present invention. Figure 3 This is a schematic diagram of the power setting process in one embodiment of the present invention; Figure 4 This is a schematic diagram of the flood discharge collaborative decision-making process in one embodiment of the present invention. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on 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.

[0021] Example: In one embodiment, such as Figure 1 As shown, a reservoir-based variable-power gravity energy storage device is provided. The device includes a foldable flexible water bag, a winch-generator integrated unit, a mobile platform, and a central intelligent control system, wherein: The foldable flexible water bag is equipped with a back pressure inlet valve at the top and an electrically controlled drain valve at the bottom. The winch-generator integrated machine is connected to the water bag and can switch between electric motor mode and generator mode; The mobile platform is used to carry the water bag and the winch-generator integrated machine. The mobile platform is either floating or shore-rail type and can automatically or controllably adjust its working position according to water level changes. The central intelligent control system is connected to the reservoir SCADA system, the power grid dispatching system, and the power market platform to perform global status perception, quality-velocity dual closed-loop collaborative control, and flood discharge collaborative decision-making.

[0022] Furthermore, in this embodiment, the material of the foldable flexible water bag is a high-strength waterproof fabric, and its folding structure allows for compressed storage to save space when not in use.

[0023] Furthermore, in this embodiment, the hoist-generator is equipped with a high-precision torque sensor and a speed encoder, which can respond to real-time commands for speed, torque and power.

[0024] Furthermore, in this embodiment, the central intelligent control system also includes a data fusion module, an adaptive positioning module, and a mass-velocity dual closed-loop control module, wherein: The data fusion module is used to collect real-time data on reservoir water conditions, power grid frequency regulation commands, electricity market prices, and equipment status. Furthermore, the reservoir water level information is obtained from the reservoir's SCADA system, specifically the real-time water level upstream of the dam. Inbound flow Outbound flow The forecast process line for the flood forecast over the next 6-72 hours; the power grid frequency regulation command is the automatic generation control (AGC) command issued by the power grid dispatch master station, including the target regulation power. The system includes: adjustment direction and system frequency deviation signals; the electricity market price is obtained by accessing the electricity spot market platform and acquiring the nodal price prediction curve for future days; the equipment status data is obtained by reading the GNSS coordinates, attitude tilt angles, and current water storage capacity of each water bag from each platform. (Obtained through integration via bottom flow meter), bag pressure, operating mode (electric / generator) of each winch-generator, speed, torque, winding temperature, and wire rope tension sensor data.

[0025] The adaptive positioning module plans and drives the mobile platform to the optimal working position based on the current water level. Furthermore, the adaptive positioning module, based on the current water level, plans and drives the mobile platform to the optimal operating position, including: based on the current water level... Based on the preset safe operating water depth range, the controller calculates the optimal anchoring position or track coordinates for each floating platform. Specifically: for floating platforms, the controller calculates the cable lengths that each anchor winch should retract or extend, forming a "position-tension" joint control loop to drive the platform to remain stably positioned under wind, wave, and current disturbances; for track-mounted platforms, the controller plans the movement path and drives the trolley to position the platform in an area where lifting operations can be safely carried out. This stage achieves the system's "spatial readiness."

[0026] The mass-speed dual closed-loop control module is configured to control the drainage volume by adjusting the opening of the electrically controlled drain valve at the bottom of the water bag, and dynamically calculate the lowering speed of the winch-generator integrated machine based on the real-time total mass data of the water bag, so as to achieve continuous, smooth and adjustable power generation.

[0027] Furthermore, the mass-velocity dual closed-loop control module also includes a mass decrease control loop, a speed regulation control loop, and a coupling feedback unit, wherein: The mass reduction control loop uses a preset mass reduction curve as a set value and adjusts the opening of the electrically controlled drain valve to make the total mass of the water bag decrease according to the curve. The speed regulation control loop is configured to operate according to physical formulas. Real-time calculation of target drop speed And control the hoist-generator unit to operate at this speed. Running, among which, Indicates power generation capacity. This indicates the real-time total mass of the water bag. Represents gravitational acceleration. This indicates the speed at which the water bag is lowered. Indicates the overall system efficiency; Furthermore, This represents the power output, which is the output target of the formula, i.e., the electrical power output by the winch-generator in generator mode. This represents the real-time total mass of the water bag, which is the key input variable of the formula. During the discharge process, the mass of the water bag will continuously decrease through the adjustment of the bottom electronically controlled drain valve. This represents the acceleration due to gravity, a physical constant typically taken to be approximately 9.8 m / s². This represents the descent speed of the water bag, which is the target variable that the formula needs to calculate and control in real time, namely the linear velocity of the water bag driven by the winch-generator integrated machine. The overall system efficiency is a dimensionless coefficient, usually expressed as a decimal or percentage, which covers various energy losses from mechanical transmission to power generation.

[0028] The coupling feedback unit directly uses the real-time data from the mass sensor to determine the target lowering speed. The correction ensures that the power output of the generator is precisely matched with the grid command.

[0029] In one embodiment, such as Figure 2 As shown, a method for coordinated and complementary use of reservoir-based variable power gravity energy storage and flood discharge is provided, applied to a reservoir-based variable power gravity energy storage device provided by this invention. The method includes the following steps: Step 1, Global Status Awareness and Platform Deployment: The central controller integrates reservoir water conditions, power grid demand, and market signals in real time to plan and drive the mobile platform to the optimal operating location; Step 2, “Zero Pump Consumption Energy Recharge” and Mass Setting: By opening the back pressure inlet valve at the top of the water bag, water is automatically pumped to the target mass using the reservoir water pressure. The winch-generator unit then uses an electric motor to increase the potential energy stored in the water bag. Step 3, Continuously Adjustable Power Release: Based on the target discharge power curve, dynamic matching between the decrease in water bag mass and the lowering speed is achieved through mass-velocity dual closed-loop coordinated control, ensuring smooth power output. The target lowering speed... According to the formula Real-time calculation, For power generation capacity, The total mass of the water bag in real time. It is the acceleration due to gravity. For overall system efficiency; Step 4, Flood Discharge Coordination Decision: Based on the digital twin model, a coordinated scheduling plan that takes into account flood control safety, economic benefits and equipment lifespan is generated, and proactive peak shaving operations are performed when the inflow is close to the flood limit.

[0030] Furthermore, in this embodiment, as Figure 3 As shown, in step two, by opening the back pressure valve at the top of the water bag, water is automatically pumped to the target mass using the reservoir's water pressure. The winch-generator unit then uses an electric motor to increase the potential energy stored in the water bag. This involves precise control of two processes: potential energy charging and potential energy discharging. When the system receives an energy storage command (originating from AGC demand adjustment or flood prevention pre-charging plan), it enters the potential energy charging mode. The control logic of its potential energy charging process includes: (1) Quality setting decision: First, based on the target total energy storage... (Power adjustable by target) Calculated in conjunction with duration, or by flood peak reduction. (Reverse calculation) and currently available elevation difference Calculate the required total water mass. Then, based on the status of each platform, Distribute the water to each water bag to obtain the target mass for each water bag. (2) Zero-pump-consumption water filling closed-loop control: The controller sends an opening command to the water inlet valve at the top of the designated water bag; the valve is a back pressure opening type. When the water bag reaches a certain depth, the reservoir water pressure naturally opens the valve to fill the water bag, achieving zero external energy consumption; the controller monitors the cumulative water inflow in real time through a high-precision electromagnetic flow meter at the bottom of the water bag. ;when near At that time, the valve is slowly closed using proportional adjustment, eventually at... (3) Constant power / constant speed boost control: After water filling is completed, the controller sets the winch-generator integrated machine to motor mode, and its control target can be selected as: constant power boost: if it is necessary to smoothly absorb the surplus power of the grid, the controller makes the motor driver work in power closed loop mode; according to the real-time power that the grid can absorb. System efficiency and the total weight of the water bag in real time Dynamically calculate and control the boost speed ( This allows for precise matching of input power. Constant-speed ramp-up: If the fastest possible virtual storage capacity is needed to cope with emergency flood control, the ramp-up speed should be controlled to the maximum safe speed allowed. It completes potential energy storage in the shortest time; during the lifting process, the controller continuously monitors the platform attitude and the uniformity of the wire rope load, and maintains system stability by fine-tuning the output of each winch-generator.

[0031] When the system receives a discharge command (originating from AGC demand reduction, high-price electricity periods, or water resource utilization after flood control), it enters the energy release discharge mode; the specific discharge control logic is controlled by the mass-velocity dual closed-loop control module.

[0032] Furthermore, in this embodiment, the "mass-velocity dual closed-loop coordinated control" also includes: Mass reduction control: Precise control of drainage volume is achieved by adjusting the opening of the electrically controlled drain valve, so that the total mass of the water bag decreases according to a preset curve; specifically, this includes: the controller adjusts the discharge power according to the target discharge power. (Constant value or curve changing over time), current total mass of the water bag Total planned discharge duration Using the principle of energy conservation, an optimal mass decrease curve of the water bag over time was plotted. The curve must be within the safe speed range. Inside, and These represent the maximum and minimum safe speeds that are allowed for controlling the lifting speed; according to the planned... The curve serves as the setpoint; the controller adjusts the drainage flow rate by regulating the opening of the electrically controlled drain valve at the bottom of the water bag. This makes the real-time total mass of the water bag... Precise tracking Curve; This is a flow closed-loop control process; Dynamic velocity calculation: based on real-time mass data, using physical formulas Calculate the target lowering speed; specifically including: the hoist-generator integrated machine operates in generator mode; in order to achieve quality Maintaining power generation capacity under continuously decreasing conditions To maintain a constant water level, the descent speed of the water bag needs to be adjusted in real time. According to physical formulas The controller calculates the target speed in real time. ,in, Indicates the target discharge power. Represents gravitational acceleration. The overall efficiency of a system is dimensionless and is usually expressed as a decimal or percentage; generator drives, on the other hand, use... The set value is used for speed-torque closed-loop control to drive the water bag to be lowered at this speed; Coupling feedback: Mass sensor data is directly used for velocity target correction, forming a strongly coupled closed loop to suppress power fluctuations; specifically, this includes: two loops strongly coupled through a central controller. The feedback value from the mass sensor... It directly participates in the calculation of the speed target value. Any quality tracking deviation caused by valve response delay or water flow inertia will immediately trigger a corresponding adjustment to the speed target, thereby ensuring the overall electrical power output at the generator end. Highly stable at the target discharge power Nearby, the fluctuations are much smaller than those of traditional tiered switching methods, achieving truly smooth and continuous frequency modulation.

[0033] Furthermore, in this embodiment, as Figure 4 As shown, the flood discharge coordination decision in step four includes: Long-term forecasting optimization: Using graph neural networks or reinforcement learning algorithms, simulate the impact of different scheduling strategies on flood control indicators, power plant revenue and equipment losses within a predetermined future time period. Furthermore, the simulation of the impact of different scheduling strategies on flood control indicators, power plant revenue, and equipment losses within a predetermined future timeframe (72 hours) using graph neural networks or reinforcement learning algorithms is based on the system's built-in digital twin module. This is achieved through a rolling execution of an AI scheduler (based on GNN / reinforcement learning), including: first, inputting the flood forecast for the next 72 hours, the spot electricity price forecast, and the current health status of the equipment; then, performing simulations in the twin environment, simulating the changes in reservoir flood control indicators (maximum water level, peak reduction), power plant revenue, and equipment losses under different scheduling strategies (e.g., when and at what scale to pump water, when to discharge water); finally, making optimization decisions to maximize the multi-objective reward function (…). With the objective of [target], output a forward-looking collaborative scheduling plan. For example: "The flood peak is expected in 8 hours." Upon arrival, it is recommended to start charging all platforms to 50% capacity 4 hours in advance to reduce the flood peak. After the flood peak, electricity was discharged in three batches during the peak electricity price period the following day. Real-time linkage control: When the inflow exceeds the limit, multiple sets of water bags are simultaneously raised to create "virtual storage capacity" and linked with the flood discharge gate system to ensure safe avoidance; Furthermore, when the inflow rate exceeds the limit, multiple sets of water bags are simultaneously raised to create a "virtual reservoir capacity," and this is coordinated with the floodgate system to ensure safe avoidance, including: Active peak shaving control: when real-time When the flow rate approaches or exceeds the flood control limit, the controller immediately executes the pre-planning or initiates real-time optimization. It issues synchronous lift commands to the selected platform group, raising a large volume of water to a higher position in a short period of time. This action is equivalent to instantly adding the storage capacity of a "virtual reservoir," directly reducing the outflow through the dam during the same period and playing a proactive role in peak shaving. The controller reports this change in virtual storage capacity to the reservoir dispatch center in real time, serving as key information for comprehensive flood control decision-making. Safety linkage and avoidance: The controller establishes a millisecond-level communication link with the floodgate control system; the control logic has built-in priorities: a) When the system determines that its peak reduction capacity has reached its limit, it will issue an early warning and suggest starting the physical gate to release floodwater; b) When it receives the instruction that the gate is about to open, the controller can immediately plan and execute the path for the platform to be urgently moved out of the flood discharge flow area, or urgently lower the water bag to a safe water depth to ensure the absolute safety of the equipment.

[0034] Value recovery: After the flood control pressure is relieved, the discharge plan is optimized based on the real-time electricity price signal to convert the stored flood potential energy into high-priced electricity.

[0035] In one embodiment, the mobile platform of the present invention includes a floating platform with an anchor propulsion system and a fixed track platform with a drive trolley, wherein the anchor propulsion system includes an electric propeller and an anchor chain tension adjustment device, which can automatically adjust the anchor position according to changes in water level. Furthermore, both the mooring propulsion system of a floating platform and the drive trolley of a fixed track platform must be able to move according to the water level and instructions; a completely fixed platform cannot adapt to large changes in reservoir water level and avoidance requirements.

[0036] In one embodiment, the central intelligent control system of the present invention further includes a fault diagnosis and adaptive operation and maintenance module for real-time monitoring of equipment status, execution of safe shutdown strategies, and predictive maintenance; specifically including: operational safety monitoring: stress and strain sensors monitor changes in the water bag in real time; if abnormal stress concentration occurs, the controller can locally reduce the load or stop the operation of the water bag. The platform stability monitoring system adjusts the anchor chain tension or counterweight in real time to prevent overturning when the mass changes rapidly; adaptive fault handling: in the event of power grid failure, communication interruption, or equipment malfunction, the controller can execute a preset emergency shutdown strategy and report a maintenance request.

[0037] Experimental example: Experimental Example 1: Example of coordinated operation of energy storage and flood control in hydropower stations during the flood season.

[0038] This case study describes the application of the present invention in a large hydropower station in East China. This power station experiences frequent flooding during the flood season. Under traditional operation, a large amount of floodwater needs to be discharged through the spillway (water wastage), resulting in energy waste; simultaneously, the power grid's demand for rapid frequency regulation is difficult to meet. Specific applications are as follows: I. System Deployment Six standardized "floating platform + smart water bag" modules have been deployed in the deep water area 1 kilometer in front of the reservoir dam. The platforms are secured by anchor chains and can automatically rise and fall with the water level. Each platform is equipped with multiple winches-generators, with specially designed foldable large water bags (each with a volume of approximately 80 cubic meters) suspended below. All equipment is managed by a central intelligent control system, which is connected to the hydropower station's Supervisory Control and Data Acquisition (SCADA) system and the power grid dispatching system.

[0039] II. Core Operational Process (A Typical Flood Season Day) 1. Forecasting and Decision-Making (Before the Flood) At 8:00 AM, the intelligent control system received a flood forecast for the next 6 hours: the flood peak was expected to occur at 2:00 PM. The system simultaneously analyzed the electricity price curve for the day. Through rapid calculations using its internal "digital twin" model, the system automatically generated the optimal solution: before the flood arrives, use the platform's water storage tanks to "store" some water to help the reservoir reduce peak flow; after the flood, use the stored water to generate electricity when prices are high to make money.

[0040] 2. Implement flood control and peak reduction measures (12:00 PM - 1:00 PM) The system automatically issued instructions, and all platforms entered "flood prevention mode," including: Zero-energy water filling: When the platform is moved to the work site, the valve on the top of the water bag opens automatically. Using the water pressure of the reservoir itself, the water quickly fills each water bag within minutes, without the need for any water pumps to consume electricity; Synchronous water lifting and energy storage: After filling (each water bag weighs approximately 80 tons), all winches and generators start simultaneously, collectively lifting the water bags to a height of about 20 meters above the water surface. This process is equivalent to instantly adding nearly 500 cubic meters of "virtual water storage capacity" to the reservoir, pre-storing a portion of the floodwater.

[0041] When the flood peak actually arrived at 2 p.m., this part of the water had been "stored" in a high place in advance, which effectively reduced the flood storage pressure on the reservoir, helped lower the flood peak water level, and improved flood control safety.

[0042] 3. Convert to electricity generation for profit (8 PM - 10 PM) After the flood warning is lifted, the peak evening electricity consumption period begins, with the highest electricity prices. At this time, the power grid also issues frequency regulation commands to increase power generation, including: Intelligent switching mode: The control system immediately switches the system to "power generation frequency regulation mode"; Continuous and controllable power discharge: The system's core control technology begins to operate. It simultaneously controls two actions: first, it causes the valve at the bottom of the water bag to drain water at a precise rhythm, reducing the weight of the water bag at a uniform rate; second, it adjusts the descent speed of the water bag in real time based on the weight changes. Through the precise coordination of these two actions, the power output of the generator remains stable, perfectly meeting the regulation requirements of the power grid. Value recovery: During the two hours when electricity prices are highest, the system converts all the potential energy of the water stored during the day into electrical energy (about 1.5 megawatt-hours) and feeds it back to the power grid, realizing the value transformation of "abandoned floodwater" into "high-priced electricity".

[0043] Example 2: A case study of the downstream regulating reservoir of a cascade hydropower station in North China.

[0044] This case study demonstrates the successful application of this invention in the downstream regulating reservoir of a cascade hydropower station in North China. The reservoir has a relatively small capacity, is located adjacent to a major town downstream, and faces significant flood control pressure. Simultaneously, the reservoir plays a crucial role in providing peak-shaving services to the regional power grid. In traditional operation, the conflict between flood control and power generation is prominent: to ensure the safety of the town, water often needs to be released in advance during the flood season, reducing power generation efficiency; and the limited regulating rate of the turbine units is insufficient to meet the rapid peak-shaving demands of the power grid.

[0045] I. Rapid System Deployment To address the challenges posed by the open waters and significant water level fluctuations in front of the reservoir dam, a "track-mounted mobile platform" solution was adopted. An approximately 800-meter-long arc-shaped heavy-duty track was laid along a suitable area on the reservoir bank. Six integrated platform modules were mounted on the track trolley, allowing for automatic movement along the track as the reservoir water level rises and falls, maintaining the optimal operating depth. Each platform is equipped with two high-power winch-generator units and four large, foldable water bags (each with a volume of 60 cubic meters). The central controller of the entire system achieves millisecond-level data communication with the reservoir dispatch center and the automatic generation control (AGC) system of the power grid.

[0046] II. Integrated and Collaborative Operation Process (Taking a complete process of responding to a rainstorm and flood as an example) Phase 1: Intelligent Early Warning and Proactive Preparation (24 hours before the rainstorm) The central controller receives heavy rain warnings and detailed flood forecasts issued by the meteorological department. The digital twin model immediately starts simulation and comparison of multiple scenarios, taking into account the future flood process, current reservoir capacity, downstream protection targets, and electricity price signals for the next 48 hours.

[0047] Twelve hours before the rainstorm, the system automatically generates and executes a pre-decision plan: "The flood peak will pass tonight, so we have decided to activate four platforms. Energy storage operations will begin three hours before the flood peak arrives to maximize peak shaving; during the peak electricity consumption period at noon the day after the flood peak, flexible discharge will be implemented to support grid peak shaving and obtain electricity price revenue." Phase Two: Precise Peak Shaving and Flood Control Coordination (Nighttime of Heavy Rain, Flood Rising Phase) At midnight, radar echoes showed continued heavy rainfall, and inflow into the reservoir began to surge. The system automatically activated four designated platforms as planned, including: Static pressure charging: The platform moves to the work site, and the water inlet valve of the water bag is opened. Utilizing the natural pressure of the reservoir's approximately 25-meter depth (approximately 0.25 MPa), water is rapidly injected into the water bag, filling it in about 7 minutes, with no additional electrical energy consumption throughout the process. A total of approximately 960 cubic meters of water is filled into the "flexible container." Synchronous and rapid lifting: After filling, the winch-generator starts simultaneously, lifting the water bag cluster 15 meters in high-efficiency mode. This operation is equivalent to instantly adding nearly a thousand cubic meters of "elastic storage capacity" to the reservoir, effectively "absorbing" a portion of the incoming water when the floodwaters rise most rapidly. Actual effect: When the actual flood peak arrived in the early morning, because this part of the water had been temporarily moved to higher ground, it was calculated that the flood peak flow was reduced by about 15 cubic meters per second, which helped the reservoir control the highest water level and keep it below the warning water level of the downstream levee, significantly alleviating the flood control pressure.

[0048] Phase 3: Flexible Peak Shaving and Value Realization (The following afternoon, during peak grid hours) After the flood threat subsided, at 13:00 the following day, the regional power grid load surged, entering its daytime peak, and electricity prices rose. Simultaneously, the AGC system issued instructions to increase output, and the system seamlessly switched to "economic peak-shaving mode." The central controller dynamically optimized the discharge strategy based on real-time electricity prices and AGC instructions, specifically including: Linear power control release: The core "mass-speed co-controller" of the system starts working, no longer pursuing rapid emptying, but controlling the valve at the bottom of the water bag to linearly adjust the drainage flow, so that the total mass of the water bag decreases smoothly; at the same time, it calculates and controls the lowering speed in real time for compensation. This makes the generator output power as smooth and continuous as adjusting the flame of a gas stove, accurately matching the grid demand curve (for example, smoothly increasing from 0 to 2 megawatts within 10 minutes and maintaining it stably).

[0049] During the two-hour midday peak, the system released all the potential energy stored overnight, providing a total of approximately 1.8 megawatt-hours of peak-shaving power. Because the discharge occurred during a period of high electricity prices, it generated considerable economic benefits, realizing the value regeneration of flood control resources.

[0050] This case fully demonstrates the broad applicability of the invention to different reservoir types (canyon type, hilly cascade type). Its core value lies in transforming the reservoir from a relatively static water conservancy facility into a dynamically adjustable smart energy node that integrates flood control, power grid frequency regulation, and market arbitrage through software-defined controllable "water bags" and intelligent collaborative algorithms, resulting in significant comprehensive benefits.

[0051] Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A reservoir-based variable power gravity energy storage device, characterized in that, include: A foldable flexible water bag with a back pressure inlet valve at the top and an electrically controlled drain valve at the bottom. The winch-generator integrated unit, connected to the water bag, can switch between electric motor mode and generator mode; A mobile platform is used to carry the water bag and the winch-generator integrated machine. The mobile platform is either floating or shore-rail type and can automatically or controllably adjust its working position according to changes in water level. The central intelligent control system communicates with the reservoir's SCADA system, the power grid dispatching system, and the electricity market platform to perform global status perception, quality-velocity dual closed-loop coordinated control, and flood discharge coordinated decision-making.

2. The apparatus according to claim 1, characterized in that, The central intelligent control system includes: The data fusion module is used to collect real-time data on reservoir water conditions, power grid frequency regulation commands, electricity market prices, and equipment status. The adaptive positioning module plans and drives the mobile platform to the optimal working position based on the current water level. The mass-speed dual closed-loop control module is configured to control the drainage volume by adjusting the opening of the electrically controlled drain valve at the bottom of the water bag, and dynamically calculate the lowering speed of the winch-generator integrated machine based on the real-time total mass data of the water bag, so as to achieve continuous, smooth and adjustable power generation.

3. The apparatus according to claim 2, characterized in that, The mass-velocity dual closed-loop control module further includes: The mass reduction control loop uses a preset mass reduction curve as the set value and adjusts the opening of the electrically controlled drain valve to make the total mass of the water bag decrease according to the curve. The speed regulation control loop is configured to operate according to physical formulas. Real-time calculation of target drop speed ,in, For the target power generation, The total mass of the water bag in real time. It is the acceleration due to gravity. To improve overall system efficiency, and to control the hoist-generator integrated machine at this speed run; The coupling feedback unit directly uses real-time data from the mass sensor to determine the target lowering speed. The correction ensures that the power output of the generator is precisely matched with the grid command.

4. The apparatus according to claim 1, characterized in that, The foldable flexible water bag is made of high-strength waterproof fabric, and its folding structure allows for compressed storage when not in use to save space.

5. The apparatus according to claim 1, characterized in that, The hoist-generator is equipped with a high-precision torque sensor and speed encoder, enabling it to respond to real-time commands for speed, torque, and power.

6. A method for coordinated and complementary use of variable power gravity energy storage and flood discharge based on a reservoir, applied to the device described in any one of claims 1-5, characterized in that, Includes the following steps: Step 1, Global Status Awareness and Platform Deployment: The central controller integrates reservoir water conditions, power grid demand, and market signals in real time to plan and drive the mobile platform to the optimal operating position; Step 2, "Zero Pump Consumption Energy Recharge" and Mass Setting: By opening the back pressure inlet valve at the top of the water bag, water is automatically pumped to the target mass using the reservoir water pressure. The winch-generator unit uses electric motor mode to increase the potential energy stored in the water bag. Step 3, Continuously Adjustable Power Release: Based on the target discharge power curve, dynamic matching between the decrease in water bag mass and the lowering speed is achieved through mass-velocity dual closed-loop coordinated control, ensuring smooth power output; wherein, the target lowering speed... According to the formula Real-time calculation, For power generation capacity, The total mass of the water bag in real time. It is the acceleration due to gravity. For overall system efficiency; Step 4, Flood Discharge Coordination Decision: Based on the digital twin model, a coordinated scheduling plan that takes into account flood control safety, economic benefits and equipment lifespan is generated, and proactive peak shaving operations are performed when the inflow is close to the flood limit.

7. The method according to claim 6, characterized in that, The flood discharge coordination decision-making in step four further includes: Long-term forecasting optimization: Using either graph neural networks or reinforcement learning algorithms, simulate the impact of different scheduling strategies on flood control indicators, power plant revenue, and equipment losses within a predetermined future time period. Real-time linkage control: When the inflow exceeds the limit, multiple sets of water bags are simultaneously raised to create "virtual storage capacity" and linked with the flood discharge gate system to ensure safe avoidance; Value recovery: After the flood control pressure is relieved, the discharge plan is optimized based on the real-time electricity price signal to convert the stored flood potential energy into high-priced electricity.

8. The method according to claim 6, characterized in that, The "mass-velocity dual closed-loop coordinated control" in step three further includes: Mass reduction control: The drainage volume is precisely controlled by adjusting the opening of the electrically controlled drain valve, so that the total mass of the water bag decreases according to the preset curve; Dynamic velocity calculation: based on real-time mass data, using physical formulas Calculate the target drop speed; Coupling feedback: Mass sensor data is directly used for velocity target correction, forming a strongly coupled closed loop to suppress power fluctuations.

9. The apparatus according to claim 1, characterized in that: When the mobile platform is floating, its mooring propulsion system includes an electric propulsion unit and an anchor chain tension adjustment device, which can automatically adjust the mooring position according to changes in water level.

10. The apparatus according to claim 1 or the method according to claim 6, characterized in that: The central intelligent control system further includes a fault diagnosis and adaptive operation and maintenance module, which is used to monitor equipment status in real time, execute safe shutdown strategies, and perform predictive maintenance.

Images