Wind power tower gravity energy storage system and control method, equipment and medium thereof

Abstract

The invention discloses a gravity energy storage system of a wind power tower, a control method of the gravity energy storage system, equipment and a medium, and relates to the technical field of renewable energy source grid connection and mechanical energy storage. The system comprises a tower supporting structure, an energy storage mass module, a traction module, a winding drum-electro-mechanical conversion module, a power conversion and protection module and a monitoring and communication module. The energy storage mass module is suspended on a vertical axis in the tower drum supporting structure through the traction module and is connected with the winding drum-electromechanical conversion module through the traction module, and the winding drum-electromechanical conversion module is arranged at the top of the tower drum supporting structure; and a motor of the winding drum-electro-mechanical conversion module is connected with the traction module. Through the combination of a tower built-in gravity energy storage structure and a rapid control strategy, tower resonance and vibration can be suppressed, the frequency change rate of a power grid is reduced, and the operation stability and reliability of a wind turbine generator and a power system are improved.

Description

Technical Field

[0001] This invention relates to the field of renewable energy grid connection and mechanical energy storage technology, and in particular to a wind turbine tower gravity energy storage system and its control method, equipment and medium. Background Technology

[0002] As the global carbon neutrality process accelerates, renewable energy is gradually becoming the main power source for power systems. The proportion of wind and solar power in the global power generation structure continues to rise, and their output power is susceptible to climate and wind speed changes, leading to increased frequency fluctuations and stability risks in power systems. To address the high proportion of renewable energy integration, long-duration and large-scale energy storage (LLDES) technologies are considered crucial for achieving flexible system regulation and safe operation. However, existing LLDES systems also face structural constraints: pumped hydro storage is limited by terrain and water resource conditions, resulting in long construction cycles; compressed air storage relies on specific geological environments such as salt caverns or abandoned mines, limiting site selection; hydrogen storage, while having high energy density, suffers from low conversion efficiency and safety risks; and thermal storage is constrained by material separation, corrosion, and heat loss issues. These limitations make it difficult for existing solutions to simultaneously achieve economic viability, sustainability, and scalability, necessitating new energy storage approaches to enhance system resilience and support the low-carbon transition.

[0003] Gravity energy storage (GES), a mechanical energy storage method based on potential energy conversion, boasts advantages such as simple structure, stable operation, and long lifespan, enabling continuous output for multiple hours. Although it has been validated in various structures such as towers and shafts in recent years, these independent structures generally suffer from high civil engineering costs and poor compatibility with existing wind power facilities. Based on structural characteristics, GES can be divided into two categories: artificial structure and terrain-adaptive. Artificial structure types, such as towers and shafts, offer flexible site selection but have high construction costs; terrain-adaptive types, such as slope-mounted and mine-mounted types, achieve low-cost deployment by relying on natural elevation differences but are significantly limited by geographical conditions. Therefore, embedding GES functionality into existing infrastructure while considering both economic efficiency and deployability has become a research hotspot. On the other hand, with the continuous increase in the proportion of wind power installed capacity, the rapid fluctuations in its output power and the design of full-power converter interfaces have led to a significant decrease in the rotational inertia of wind power systems. Currently, most wind turbines are decoupled from the grid through converters, which cannot directly provide mechanical inertia support. This results in a decrease in the overall inertia level of the system and an increase in the rate of change of frequency (RoCoF). When there are sudden changes in wind speed or load steps, problems such as frequency deviation exceeding limits and low-frequency oscillations may occur, and in severe cases, the unit may even disconnect from the grid.

[0004] To enhance the inertial response capability of wind power systems, existing research has explored the use of mechanical energy storage devices such as flywheels and synchronous condensers, or the provision of inertial support through flywheel-battery combined systems and phase-regulation-capacitor composite systems. However, these solutions generally suffer from high system complexity, poor response continuity, insufficient physical inertia, and high maintenance costs, making them difficult to promote and apply in remote wind farms or space-constrained scenarios. Furthermore, gravity energy storage, due to its large mechanical inertia, stable response, and long operational life, is considered a potential energy storage pathway for inertia enhancement. However, traditional GES systems typically require the construction of independent towers or shafts, resulting in high civil engineering costs and large land requirements, hindering flexible deployment within wind farm clusters. Existing composite GES solutions are mostly deployed in a split manner, with the energy storage unit separated from the wind turbine's main control system, failing to achieve deep integration and making it difficult to respond to grid frequency changes on a millisecond timescale.

[0005] Therefore, there is an urgent need for a wind turbine tower gravity energy storage system, its control method, equipment and medium, which embeds gravity energy storage units inside the wind turbine tower to provide mechanical inertia support and energy balance regulation, so as to achieve the integration of energy storage and inertia support without changing the main structure of the wind turbine, thereby improving the dynamic stability and regulation capability of the wind power system. Summary of the Invention

[0006] The purpose of this invention is to propose a wind turbine tower gravity energy storage system and its control method, equipment and medium to solve the problems of insufficient inertia support capacity, significant frequency fluctuations and limited site selection of existing wind power systems. At the same time, it overcomes the defects of traditional gravity energy storage, which requires separate construction of shafts or towers, has high cost and low integration, and achieves high integration of energy storage structure and unified engineering feasibility.

[0007] In a first aspect, to achieve the above objectives, the present invention provides a wind turbine tower gravity energy storage system, comprising: a tower support structure, an energy storage mass module, a traction module, a drum-electromechanical conversion module, a power conversion and protection module, and a monitoring and communication module;

[0008] The energy storage mass module is suspended on the vertical axis inside the tower support structure via the traction module, and is connected to the drum-electromechanical conversion module via the traction module. The drum-electromechanical conversion module is located at the top of the tower support structure. The load-bearing capacity of the tower support structure is matched with the target weight and dynamic load of the energy storage mass module.

[0009] The drum-electromechanical conversion module includes a motor and a drum mechanism with bidirectional drive and energy feedback functions, used to drive the energy storage mass module to move up and down in the vertical direction; the motor of the drum-electromechanical conversion module is connected to the traction module, and both the drum-electromechanical conversion module and the traction module are connected to the wind turbine main control system through a communication interface;

[0010] The drum-electromechanical conversion module is connected to the power conversion and protection module. The power conversion and protection module is installed on the electrical platform of the tower support structure. The power conversion and protection module is also connected to the communication terminals of the wind turbine main control system and the monitoring and communication module. The monitoring and communication module is connected to the wind turbine main control system. The sensor components of the monitoring and communication module are distributed at key monitoring points of the drum-electromechanical conversion module, the energy storage quality module, and the tower support structure.

[0011] Optionally, the energy storage mass module is made of high-density material, and a limiting or guiding component is provided between the energy storage mass module and the inner wall of the tower support structure;

[0012] The high-density material includes concrete, cast iron, or composite metal. The limiting or guiding component is a guide rail arranged axially along the inner wall of the tower support structure and cooperating with the outer slider of the energy storage mass module, or a wake-up guide ring structure. The energy storage mass module is configured according to the tower support structure.

[0013] Optionally, the traction module includes several steel cables and pulley blocks, and the traction module is equipped with a fall prevention or braking device, which is an electromagnetic braking mechanism or a mechanical pawl locking structure.

[0014] The load-bearing capacity of the steel cable is determined by the energy storage mass module.

[0015] Optionally, the rated breaking tensile strength of the steel cable is not less than five times the weight of the energy storage mass module, and the fatigue life is not less than 10. 5 The cycle of rising and falling repeats.

[0016] Optionally, the power conversion and protection module includes a converter, a braking resistor, a limit switch, a travel detector, and a bottom buffer device;

[0017] The bottom buffer device adopts a spring-hydraulic composite structure.

[0018] Optionally, the monitoring and communication module includes a position sensor, a speed sensor, a load sensor, a stress sensor, and a temperature sensor;

[0019] The position sensor is used to collect the height of the energy storage mass module in real time;

[0020] The speed sensor is used to monitor the rise and fall rate of the energy storage mass module.

[0021] The load sensor is used to detect the tension in the steel cable;

[0022] The stress sensor is used to monitor the stress changes in key parts of the tower support structure;

[0023] The temperature sensor is used to monitor the temperature of the motor and the converter.

[0024] Secondly, to achieve the above objectives, the present invention provides a control method for a wind turbine tower gravity energy storage system, comprising:

[0025] The real-time output power of the wind turbine main control system and the grid frequency are collected, and the target power setpoint and the tower natural frequency are combined to calculate the grid power deviation and grid frequency deviation.

[0026] Determine whether the power grid frequency deviation is greater than a preset frequency deviation range. If so, execute the inertia support mode; otherwise, execute the energy balance control mode.

[0027] The inertia support mode is as follows: execute a lifting action consistent with the frequency deviation of the power grid, determine the power command by calling a preset frequency deviation and lifting power mapping table, and execute the first operation;

[0028] The energy balance control mode is as follows: if the power deviation of the grid is greater than the power deviation threshold, the energy storage quality module is controlled to rise to absorb redundant energy as the control result of the wind turbine tower gravity energy storage system; otherwise, the energy storage quality module is controlled to descend to release energy as the control result of the wind turbine tower gravity energy storage system.

[0029] The first operation is to constrain the rise and fall rate of the power command based on the filtering algorithm of the tower's natural frequency until the grid frequency deviation recovers to the preset frequency deviation range, and then execute the energy balance control mode.

[0030] Optionally, the method further includes:

[0031] Based on the mapping table between the frequency deviation and the power increase / decrease, the inertia response coefficient is dynamically adjusted according to the power grid frequency deviation;

[0032] Determine whether the inertial response coefficient is less than or equal to an inertial response coefficient threshold. If so, the inertial response coefficient is set to 0.5-1Hz. -1 The frequency deviation and the rise / fall power command output by the mapping table of rise / fall power are corrected by the inertia response coefficient; otherwise, the inertia response coefficient is taken as 1-2Hz. -1 The frequency deviation and the power increase / decrease command output by the mapping table of power increase / decrease are corrected by the inertia response coefficient.

[0033] Thirdly, to achieve the above objectives, the present invention provides an electronic device, comprising: one or more processors; and a storage device having one or more programs stored thereon, wherein when the one or more programs are executed by the one or more processors, the one or more processors implement the method described in any implementation of the second aspect.

[0034] Fourthly, to achieve the above objectives, the present invention provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by one or more processors, implements the method as described in any implementation of the second aspect.

[0035] Compared with the closest existing technology, the present invention has the following advantages:

[0036] The wind turbine tower gravity energy storage system of this invention integrates energy storage and power generation structures, offering advantages such as simple structure, rapid response, reliable operation, and easy expansion. It is widely applicable to new wind turbine tower integration projects or existing tower retrofit projects, providing a safe, economical, and highly adaptable inertial support and energy balance solution for power systems with high wind power grid connection. By combining a tower-embedded gravity energy storage structure with a rapid control strategy, this invention can suppress tower resonance and vibration, reduce grid frequency variation rate, and improve the operational stability and reliability of wind turbines and the power system. Compared with existing independent gravity energy storage systems, flywheel energy storage, or synchronous condensers, this invention has the following significant technical effects:

[0037] (1) Structural integration and near-zero additional civil engineering requirements: The internal space of the wind turbine tower is reused to arrange the energy storage unit, eliminating the need for additional towers or shafts, reducing project investment and improving space utilization.

[0038] (2) Dual-function integrated operation: The system is deeply linked with the main control system of the wind turbine to realize the integration of energy management and mechanical inertia support functions, thereby improving the frequency stability of the power grid.

[0039] (3) Fast response and stable support: Based on the "frequency deviation - power increase and decrease" mapping table and 100 millisecond level response control, fast inertia injection is achieved, which significantly reduces the grid frequency change rate.

[0040] (4) Multiple safety protections: Equipped with steel cables with a breaking strength of five times, double braking locking devices and spring-hydraulic buffer structure, significantly improving operational reliability.

[0041] (5) Engineering adaptability and scalability: It is suitable for the integration of new wind turbine towers and the renovation of existing towers. It can be used as a black start power source or structural damper for tower vibration suppression, providing a highly reliable and scalable energy storage solution for large-scale wind power access. Attached Figure Description

[0042] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific 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 from these drawings without creative effort.

[0043] Figure 1 This is a schematic diagram of a wind turbine tower gravity energy storage system according to an embodiment of the present invention;

[0044] Figure 2 This is a schematic diagram illustrating the charging operation principle of the wind turbine tower gravity energy storage system proposed in an embodiment of the present invention.

[0045] Figure 3 This is a schematic diagram illustrating the discharge operation principle of the wind turbine tower gravity energy storage system proposed in an embodiment of the present invention.

[0046] Figure 4 This is a schematic diagram of the inertia support principle of the wind turbine tower gravity energy storage system proposed in an embodiment of the present invention;

[0047] Figure 5 This is a schematic diagram of the dynamic response of the wind turbine tower gravity energy storage system proposed in this embodiment of the invention under frequency disturbance;

[0048] Figure 6 The above are frequency fluctuation comparison curves of the wind turbine tower gravity energy storage system proposed in this embodiment of the invention under different operating modes.

[0049] Figure 7 This is a schematic diagram of the structure of the electronic device proposed in an embodiment of the present invention. Detailed Implementation

[0050] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions in the embodiments of this invention will be clearly and completely described below with reference to specific embodiments and corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0051] The terminology used in the embodiments section of this invention is for the purpose of explaining specific embodiments of the invention only, and is not intended to limit the invention.

[0052] The existing technology still has the following shortcomings: (1) The construction cycle of independent GES systems is long and the investment is large, making it difficult to deploy on a large scale; (2) The mechanical inertia of existing wind turbine units is insufficient and the frequency stability is poor; (3) The energy storage and the unit control system are separated, making it impossible to achieve rapid linkage and precise energy management. Therefore, there is an urgent need for a wind turbine tower gravity energy storage system that does not require additional civil engineering, can be embedded in the internal structure of the wind turbine tower, and has mechanical inertia response function, as well as its control method, equipment and medium.

[0053] This invention provides a wind turbine tower gravity energy storage system, such as... Figure 1 As shown, the system utilizes the internal space of the wind turbine tower to embed the energy storage mass unit, enabling the wind turbine tower to simultaneously possess the combined functions of wind power generation and gravity energy storage. The system mainly includes: tower support structure, energy storage mass module, traction module, drum-electromechanical conversion module, power conversion and protection module, and monitoring and communication module.

[0054] The energy storage mass module is suspended on the vertical axis inside the tower support structure via the traction module, reducing the interference of wind load on the lifting operation and thus improving operational stability. The energy storage mass module is connected to the drum-electromechanical conversion module installed on the top of the tower support structure via the traction module. The load-bearing capacity of the tower support structure is matched with the maximum weight of the energy storage mass module and the dynamic load it generates. This internal suspension layout can reduce the interference of wind load on the lifting operation, improve the system's operational stability, and avoid the construction complexity caused by external auxiliary structures.

[0055] The drum-electromechanical conversion module is installed on the top platform of the tower support structure. This module includes a motor and a drum mechanism with bidirectional drive and energy feedback functions, used to drive the energy storage mass module to move vertically, thereby realizing bidirectional conversion of electrical energy and gravitational potential energy through the drum-electromechanical conversion module. The traction module is connected to the motor of the drum-electromechanical conversion module, and the motor is electrically connected to the power conversion and protection module, which is used for energy conversion (such as current conversion) and transmission control. Both the drum-electromechanical conversion module and the traction module are connected to the wind turbine main control system through a communication interface. The drum-electromechanical conversion module is linked with the wind turbine main control system through the communication interface to realize the coordination of operation command response and energy flow, and to achieve unified energy scheduling and inertia support. The traction module is communicatively connected to the wind turbine main control system to provide status monitoring data in the event of power fluctuations or grid frequency disturbances, assisting in energy balance adjustment and mechanical inertia support.

[0056] The drum-electromechanical conversion module is connected to the power conversion and protection module. The power conversion and protection module is installed on the electrical platform of the tower support structure. The power conversion and protection module is also connected to the communication terminal of the wind turbine main control system control and monitoring and communication module. The monitoring and communication module is connected to the wind turbine main control system. The sensor components of the monitoring and communication module are distributed at key monitoring points of the drum-electromechanical conversion module, the energy storage quality module, and the tower support structure.

[0057] Specifically, the power conversion and protection module is installed at the bottom of the tower support structure or on the internal electrical platform, and the sensor components of the monitoring and communication module are distributed according to the monitoring objects at key monitoring points of the drum-electromechanical conversion module, the energy storage quality module, and the tower support structure.

[0058] In some optional embodiments, the energy storage mass module is made of a high-density material selected from concrete, cast iron, or composite metal materials, and can adopt a modular structure for easy hoisting and maintenance. A limiting or guiding component is provided between the energy storage mass module and the inner wall of the tower support structure. Specifically, this is a guide rail arranged axially along the inner wall of the tower support structure that cooperates with a slider on the outer side of the energy storage mass module, or an annular guide ring structure, to prevent lateral swaying and ensure smooth lifting. The weight, dimensions, and lifting stroke of the energy storage mass module are adapted to the load-bearing capacity and operating conditions of the tower support structure to ensure structural safety while also considering energy storage efficiency.

[0059] In the application of newly built wind turbine tower integration or the retrofitting of existing wind turbine towers, the energy storage mass module is dynamically configured by adjusting its weight and lifting stroke based on the test results of the tower support structure strength. The weight of the energy storage mass module preferably does not exceed 80% of the rated load of the tower support structure, and the lifting stroke preferably does not exceed 70% of the effective height of the tower support structure. If the tower support structure is structurally reinforced, such as by adding reinforcing bars or optimizing material strength, the weight and lifting stroke can be adjusted accordingly based on the reinforced load-bearing capacity. After adjustment, the safety factor of the tower structure must be not less than 1.2.

[0060] In some optional embodiments, the traction module includes: a multi-strand steel cable and a pulley system. The load-bearing capacity of the steel cable meets the structural safety and fatigue life design requirements and is determined by the energy storage mass module. Specifically, the rated breaking tensile strength of the steel cable is not less than five times the weight of the energy storage mass module, and the fatigue life is not less than 10. 5 The lifting and lowering cycle is repeated. To ensure operational safety, the traction module is equipped with an anti-fall or braking device, which can be an electromagnetic braking mechanism or a mechanical pawl locking structure, used to automatically lock the position of the energy storage mass module in the event of cable breakage, overspeed, or instability.

[0061] In some optional implementations, the power conversion and protection module is used to realize bidirectional flow of electrical energy and safety control, and mainly includes: a converter, a braking resistor, a limit switch, a travel detector and a bottom buffer device.

[0062] The converter is used to connect the motor to the grid interface of the wind turbine, control the switching of the motor between motoring and generating states, and realize bidirectional conversion and power regulation of electrical energy and mechanical energy; the braking resistor is used to absorb feedback energy during emergency braking to prevent overvoltage damage; the limit switch and the travel detector are used to determine the extreme position of the energy storage mass module and trigger the protection logic; the bottom buffer device adopts a spring-hydraulic composite structure to absorb the impact of falling, thereby ensuring the safety of the system's electrical circuit and the integrity of the mechanical structure, and ensuring the safety of the mechanical structure and tower.

[0063] In some optional implementations, the monitoring and communication module includes: a position sensor, a speed sensor, a load sensor, a stress sensor, and a temperature sensor, used to collect key status information such as the height of the mass module, the lifting rate, the tension of the steel cable, the stress of the tower, and the temperature of the motor.

[0064] The position sensor is used to collect the height of the energy storage mass module in real time; the speed sensor is used to monitor the lifting and lowering rate of the energy storage mass module; the load sensor is used to detect the tension of the steel cable; the stress sensor is used to monitor the stress changes of key parts of the tower support structure; and the temperature sensor is used to monitor the temperature of the motor and converter. These sensor signals are transmitted in real time to the power conversion and protection module to trigger overload, overtravel, and stress over-limit protection interlock actions. Simultaneously, it communicates with the wind turbine main control system via Ethernet or CAN bus to achieve data synchronization and coordinated control.

[0065] It should be noted that the implementation details and technical effects of each module and unit in the system provided by the embodiments of this disclosure can be referred to the descriptions of other embodiments in this disclosure, and will not be repeated here.

[0066] like Figures 2-3 As shown, during operation, the wind turbine tower functions as both energy storage and power generation. When wind energy is abundant or the grid has surplus power, the system controls the motor to drive the drum, causing the energy storage mass module to rise and convert electrical energy into gravitational potential energy for storage. When grid power is insufficient or the frequency drops, the energy storage mass module descends, driving the motor to generate electricity, which is then fed back to the grid through the converter, achieving energy release and frequency support. When the grid frequency deviates, the system can provide rapid inertia support through mechanical inertia response without control delay: the rising energy storage mass module has a braking effect on the frequency increase, and the descending module provides kinetic energy support for the frequency decrease, thereby achieving transient bidirectional inertia compensation.

[0067] The control system adopts a hierarchical control architecture, including three levels: upper-level energy scheduling, middle-level power coordination, and lower-level inertia control. The upper-level control calculates the power deviation based on the real-time acquired wind turbine output power and the target power setpoint, and determines the charging / discharging state based on the direction of the deviation. The middle-level control generates lifting and lowering rate and acceleration commands based on the target lifting power and available travel. The lower-level control is responsible for executing rapid inertia response and safety constraints. This application provides a control method for a wind turbine tower gravity energy storage system, including the following steps:

[0068] S1, Collect the real-time output power P of the wind turbine main control system. a Combined with the grid frequency f and the target power setpoint P s Calculate the power grid deviation ΔP = P based on the tower's natural frequency f0. a -P s Frequency deviation from the power grid Δf = f - f0;

[0069] S2. Determine whether the power grid frequency deviation Δf is greater than the preset frequency deviation range. If yes, execute S3; otherwise, execute S4.

[0070] S3, Inertia Support Mode: Executes a lifting action consistent with the frequency deviation of the power grid. By calling the preset frequency deviation and lifting power mapping table, the power command is determined and S5 is executed.

[0071] S4. The energy balance control mode is as follows: If the power grid deviation ΔP is greater than the power grid deviation threshold (the power grid deviation threshold is 0), the energy storage quality module is controlled to rise to absorb redundant energy as the control result of the wind turbine tower gravity energy storage system; otherwise, the energy storage quality module is controlled to descend to release energy as the control result of the wind turbine tower gravity energy storage system.

[0072] S5. The power command acceleration and deceleration rate is constrained and controlled by the filtering algorithm based on the tower's natural frequency until the grid frequency deviation recovers to the preset frequency deviation range, and then the energy balance control mode is executed.

[0073] A control method for a wind turbine tower gravity energy storage system is as follows:

[0074] (a) Acquire the real-time output power P of the wind turbine main control system. a With the target power setpoint P s Calculate the power deviation ΔP=P a -P s ;

[0075] (b) When ΔP>0, i.e. power is excessive, and the energy storage quality module has an upward stroke, control the energy storage quality module to rise and absorb redundant energy;

[0076] (c) When ΔP<0, i.e. the wind turbine power is insufficient and the system is allowed to discharge, control the energy storage quality module to decrease and release energy;

[0077] (d) When the grid frequency deviation Δf is detected to be outside the set range, the control system takes precedence over step (b) or step (c) to execute the lifting action in the same direction as Δf, and directly determines the lifting power command by calling the preset "frequency deviation - lifting power" mapping table, thereby providing mechanical inertia support within a response time of about 100 milliseconds until the frequency recovers to the threshold range and then the energy balance control is restored, i.e. step (b) or step (c).

[0078] (e) The control system executes a filtering algorithm based on the tower’s natural frequency f0 to constrain the lifting rate, so that the frequency components of the lifting rate avoid the resonance band of f0±10%, even if the frequency components are outside f0±10%, in order to prevent structural resonance and overload.

[0079] As one possible implementation, in the above embodiments, the method further includes:

[0080] Based on the mapping table between the frequency deviation and the power increase / decrease, the inertia response coefficient is dynamically adjusted according to the power grid frequency deviation;

[0081] Determine whether the inertial response coefficient is less than or equal to an inertial response coefficient threshold. If so, the inertial response coefficient is set to 0.5-1Hz. -1 The frequency deviation and the rise / fall power command output by the mapping table of rise / fall power are corrected by the inertia response coefficient; otherwise, the inertia response coefficient is taken as 1-2Hz. -1 The frequency deviation and the power increase / decrease command output by the mapping table of power increase / decrease are corrected by the inertia response coefficient.

[0082] Specifically, the control system samples power and frequency signals at millisecond intervals, and based on the "frequency deviation - power increase / decrease" mapping table described in step (d), dynamically adjusts the inertia response coefficient K according to the grid frequency deviation |Δf|. i When |Δf|≤0.2Hz, K i Take 0.5-1Hz -1 When |Δf|>0.2Hz, Kᵢ takes a value of 1-2Hz. -1 And through K i The parameter correction mapping table outputs the power increase / decrease command, thereby achieving precise inertia injection or absorption that matches the amplitude of frequency disturbances.

[0083] During system operation, if overspeed, cable breakage, overload, or abnormal tower stress is detected, the control system immediately executes emergency braking, locks the position of the energy storage quality module, cuts off the energy flow, and simultaneously reports the event type, fault location, and current system status data to the wind turbine main control system, before entering a safe shutdown state. The system supports multi-tower coordinated operation. When multiple wind turbine gravity energy storage systems are connected in parallel, the main controller allocates power regulation and inertia support shares based on each unit's remaining energy storage capacity, available travel, and real-time response capability, achieving uniform response and stable operation under group control conditions. After an individual unit executes and releases emergency braking, the main control system coordinates multiple units to gradually resume lifting and lowering actions and power output in a preset sequence, avoiding grid power surges caused by simultaneous large-scale charging and discharging, and ensuring coordinated and stable operation of multiple units.

[0084] Under typical design parameters, the effective stroke of the tower can be determined based on the tower height and structural layout, typically ranging from 60 to 120 meters. The weight of individual mass modules can be modularly stacked from 10 to 50 tons, with the total mass configured according to the tower's load-bearing capacity, not exceeding 80% of the rated load. The lifting speed can be controlled between 0.1 and 1.0 meters per second, with an acceleration range of 0.1 to 0.5 meters per second squared. The fatigue life of the steel cable is designed to be no less than 10 years. 5 Each lifting cycle. The rated power of the motor and converter is configured according to the target lifting power (0.5-5 MW) and duration. Major components should meet the temperature, humidity, and salt spray level requirements of the wind farm operating environment to ensure long-term safety and durability.

[0085] like Figure 4As shown, the time-domain curves of the dynamic response of each component of the wind turbine tower gravity energy storage system proposed in this embodiment of the invention are displayed when a frequency disturbance event occurs. Specifically, sub-figure (a) (Grid frequency) shows the change of grid frequency over time, demonstrating the system's rapid response after detecting frequency fluctuations; sub-figure (b) (Velocity of mass movement) shows the change in the acceleration and deceleration speed of the energy storage mass module, indicating that the mass module releases / absorbs kinetic energy through acceleration or deceleration during inertia support; sub-figures (c) (Grid-connected current) and (d) (GES System Power Output) respectively show the fluctuations in grid-connected current and system power output, verifying the system's rapid adjustment capability on the electrical side; sub-figure (e) (Traction and gravity) compares the relationship between the cable traction force and the gravity (mg) of the energy storage mass module, reflecting the dynamic changes of mechanical load during inertia response; and sub-figure (f) (Inertia support energy) decomposes in detail the inertia support energy of the rotor, mass module, and the entire gravity energy storage system (GES system). Figure 4 It can be seen that the system has an asymmetry in its support characteristics: in charging mode, the system can effectively limit the frequency rise due to the passive inertial braking effect of the mass module; while when the frequency drops, the system uses mechanical inertia and electrical damping through control strategies to achieve rapid energy injection.

[0086] like Figure 5 The figure illustrates the system dynamic response of an embodiment of the present invention under the condition of a step change in grid load (t=1s). The figure compares the grid frequency change curves under three scenarios: "No GES", "GES Charging", and "GES Discharging".

[0087] For load increase (corresponding to) Figure 5 The frequency drop caused by the waveform on the right: When there is no GES access, the frequency drops rapidly to the lowest point of about 49.8866Hz, and the subsequent oscillation amplitude is large and the stabilization time is long; when the system is in charging mode, the lowest frequency point is raised to about 49.8902Hz by using the motor rotor inertia and fast power control, which significantly reduces the oscillation amplitude; when the system is in discharging mode, the motor rotor inertia combined with the kinetic energy release of the energy storage mass module further reduces the maximum frequency deviation from 0.1134Hz to 0.1086Hz (an improvement of about 4.2%), which not only raises the lowest frequency point (about 49.8914Hz) but also effectively suppresses frequency oscillation.

[0088] For load decline (corresponding to) Figure 5 The frequency surge caused by the waveform on the left: When there is no GES access, the frequency spikes to about 50.1113Hz; when the system is in charging mode, the energy storage quality module passively absorbs excess energy during the uplink process, playing a significant load smoothing role and controlling the frequency peak at 50.1073Hz (maximum frequency deviation improvement of about 3.6%); when the system is in discharging mode, relying on rotor inertia support, the frequency peak can also be suppressed to about 50.1085Hz.

[0089] Simulation results show that after introducing the wind turbine tower gravity energy storage system of the present invention, the maximum frequency deviation, peak-to-peak amplitude and convergence speed of the power grid are significantly improved, whether facing load surge or drop disturbances, verifying the effectiveness of the system in providing bidirectional inertia support.

[0090] like Figure 6 The figure shows a comparison curve of frequency fluctuations under the background of simulated continuous wind speed disturbance (introducing measured wind speed data sampled at 100Hz) according to an embodiment of the present invention. This figure aims to verify the system's ability to smooth the grid frequency under random wind speed fluctuation conditions. The first column (Actual wind speed) in the figure shows the input wind speed change curve from 0 to 2 seconds, with the wind speed increasing from about 8.5 m / s to 11 m / s; the second column (Only Wind Turbine) shows that when only the wind turbine is running, affected by wind speed fluctuations, the grid frequency fluctuates drastically in the range of 49.94Hz to 50.06Hz, with a maximum frequency deviation of about 0.0588Hz and a peak-to-peak amplitude of about 0.1175Hz; the third column (GES Charging) and the fourth column (GES Discharging) in the figure show the frequency response when connected to the system and running in charging and discharging modes, respectively. Data comparison shows that in charging mode, the system can compress the maximum frequency offset to 0.0341Hz, an improvement of approximately 41.96% compared to a pure wind turbine system; the peak-to-peak frequency fluctuation decreased from 0.1175Hz to 0.06797Hz, a reduction of 42.17%. Simultaneously, the standard deviation and root mean square (RMS) of the frequency deviation both decreased by approximately 29.6%. In discharging mode, the system also exhibits a significant smoothing effect, with improvements of approximately 20.64% and 21.19% in maximum frequency offset and peak-to-peak frequency, respectively.

[0091] The above results confirm that this system, through "frequency deviation-power increase / decrease" mapping control, utilizes the kinetic potential energy of the motor rotor inertia and the energy storage mass module to effectively reduce the rate of change of grid frequency (RoCoF) and fluctuation amplitude under continuous dynamic wind speed disturbances, thus significantly improving the frequency stability of wind turbine grid connection.

[0092] Through the above structural design and control methods, the wind turbine tower gravity energy storage system of the present invention realizes the integrated integration of energy storage and power generation structure. It has the advantages of simple structure, fast response, reliable operation and easy expansion. It can be widely used in new wind turbine tower integration or existing tower renovation projects, providing a safe, economical and highly adaptable inertial support and energy balance solution for power systems under high proportion of wind power grid connection.

[0093] Furthermore, the present invention also provides an electronic device. See below for reference. Figure 7 It shows a schematic diagram of the structure of a computer system 500 suitable for implementing the electronic device disclosed in this invention. Figure 7 The computer system 500 shown is merely an example and should not be construed as limiting the functionality and scope of the embodiments of this disclosure.

[0094] like Figure 7 As shown, the computer system 500 may include a processing device (e.g., a central processing unit, a graphics processing unit, etc.) 501, which can perform various appropriate actions and processes according to a program stored in a read-only memory (ROM) 502 or a program loaded from a storage device 508 into a random access memory (RAM) 503. The RAM 503 also stores various programs and data required for the operation of the computer system 500. The processing device 501, ROM 502, and RAM 503 are interconnected via a bus 504. An input / output (I / O) interface 505 is also connected to the bus 504.

[0095] Typically, the following devices can be connected to I / O interface 505: input devices 506 including, for example, touchscreens, touchpads, keyboards, mice, cameras, microphones, etc.; output devices 507 including, for example, liquid crystal displays (LCDs), speakers, vibrators, etc.; storage devices 508 including, for example, magnetic tapes, hard disks, etc.; and communication devices 509. Communication device 509 allows computer system 500 to communicate wirelessly or wiredly with other devices to exchange data. Although Figure 7 A computer system 500 with various electronic devices is shown; however, it should be understood that it is not required to implement or possess all of the devices shown. More or fewer devices may be implemented or possessed alternatively.

[0096] In particular, according to embodiments of this disclosure, the processes described above with reference to the flowcharts can be implemented as computer software programs. For example, embodiments of this disclosure include a computer program product comprising a computer program carried on a computer-readable medium, the computer program containing program code for performing the methods shown in the flowcharts. In such embodiments, the computer program can be downloaded and installed from a network via a communication device 509, or installed from a storage device 508, or installed from a ROM 502. When the computer program is executed by the processing device 501, it performs the functions defined in the methods of embodiments of this disclosure.

[0097] It should be noted that the computer-readable medium described in this disclosure can be a computer-readable signal medium or a computer-readable storage medium, or any combination thereof. A computer-readable storage medium can be, for example,—but not limited to—an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of a computer-readable storage medium may include, but are not limited to: an electrical connection having one or more wires, a portable computer disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage device, magnetic storage device, or any suitable combination thereof. In this disclosure, a computer-readable storage medium can be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, apparatus, or device. In this disclosure, a computer-readable signal medium can include a data signal propagated in baseband or as part of a carrier wave, carrying computer-readable program code. Such propagated data signals can take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. A computer-readable signal medium can be any computer-readable medium other than a computer-readable storage medium, which can send, propagate, or transmit a program for use by or in connection with an instruction execution system, apparatus, or device. The program code contained on the computer-readable medium can be transmitted using any suitable medium, including but not limited to: wires, optical fibers, RF (radio frequency), etc., or any suitable combination thereof.

[0098] The aforementioned computer-readable medium may be included in the aforementioned electronic device; or it may exist independently and not assembled into the electronic device.

[0099] The aforementioned computer-readable medium carries one or more programs, which, when executed by the electronic device, cause the electronic device to perform the following functions: Figure 7The illustrated embodiments and their alternative implementations demonstrate a control method for a wind turbine tower gravity energy storage system.

[0100] Computer program code for performing the operations of this disclosure can be written in one or more programming languages ​​or a combination thereof, including object-oriented programming languages ​​such as Java, Smalltalk, and C++, and conventional procedural programming languages ​​such as the "C" language or similar programming languages. The program code can be executed entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving remote computers, the remote computer can be connected to the user's computer via any type of network—including a local area network (LAN) or a wide area network (WAN)—or can be connected to an external computer (e.g., via the Internet using an Internet service provider).

[0101] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of this disclosure. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions indicated in the blocks may occur in a different order than those indicated in the drawings. For example, two consecutively indicated blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, can be implemented using a dedicated hardware-based system that performs the specified function or operation, or using a combination of dedicated hardware and computer instructions.

[0102] The units or modules described in the embodiments of this disclosure can be implemented in software or hardware. The names of the units or modules do not necessarily limit the unit itself; for example, an acquisition module can also be described as "acquiring preset prompts, including modality fusion prompts, attention mechanism prompts, and / or time-related prompts."

[0103] The above description is merely a preferred embodiment of this disclosure and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of this disclosure is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the above-described concept. For example, technical solutions formed by substituting the above features with (but not limited to) technical features disclosed in this disclosure that have similar functions.

Claims

1. A gravity energy storage system for wind turbine towers, characterized in that, include: Tower support structure, energy storage mass module, traction module, drum-electromechanical conversion module, power conversion and protection module, and monitoring and communication module; The energy storage mass module is suspended on the vertical axis inside the tower support structure via the traction module, and is connected to the drum-electromechanical conversion module via the traction module. The drum-electromechanical conversion module is located at the top of the tower support structure. The load-bearing capacity of the tower support structure is matched with the target weight and dynamic load of the energy storage mass module. The drum-electromechanical conversion module includes a motor and a drum mechanism with bidirectional drive and energy feedback functions, used to drive the energy storage mass module to move up and down in the vertical direction; the motor of the drum-electromechanical conversion module is connected to the traction module, and both the drum-electromechanical conversion module and the traction module are connected to the wind turbine main control system through a communication interface; The drum-electromechanical conversion module is connected to the power conversion and protection module. The power conversion and protection module is installed on the electrical platform of the tower support structure. The power conversion and protection module is also connected to the communication terminals of the wind turbine main control system and the monitoring and communication module. The monitoring and communication module is connected to the wind turbine main control system. The sensor components of the monitoring and communication module are distributed at key monitoring points of the drum-electromechanical conversion module, the energy storage quality module, and the tower support structure.

2. The wind turbine tower gravity energy storage system according to claim 1, characterized in that, The energy storage mass module is made of high-density material, and a limiting or guiding component is provided between the energy storage mass module and the inner wall of the tower support structure. The high-density material includes concrete, cast iron, or composite metal. The limiting or guiding component is a guide rail arranged axially along the inner wall of the tower support structure and cooperating with the outer slider of the energy storage mass module, or a wake-up guide ring structure. The energy storage mass module is configured according to the tower support structure.

3. The wind turbine tower gravity energy storage system according to claim 1, characterized in that, The traction module includes several steel cables and pulley blocks, and the traction module is equipped with a fall prevention or braking device, which is an electromagnetic braking mechanism or a mechanical pawl locking structure. The load-bearing capacity of the steel cable is determined by the energy storage mass module.

4. The wind turbine tower gravity energy storage system according to claim 3, characterized in that, The rated breaking tensile strength of the steel cable shall not be less than five times the weight of the energy storage mass module, and its fatigue life shall not be less than 10. 5 The cycle of rising and falling repeats.

5. A wind turbine tower gravity energy storage system according to claim 3, characterized in that, The power conversion and protection module includes a converter, a braking resistor, a limit switch, a travel detector, and a bottom buffer device; The bottom buffer device adopts a spring-hydraulic composite structure.

6. A wind turbine tower gravity energy storage system according to claim 5, characterized in that, The monitoring and communication module includes a position sensor, a speed sensor, a load sensor, a stress sensor, and a temperature sensor. The position sensor is used to collect the height of the energy storage mass module in real time; The speed sensor is used to monitor the rise and fall rate of the energy storage mass module. The load sensor is used to detect the tension in the steel cable; The stress sensor is used to monitor the stress changes in key parts of the tower support structure; The temperature sensor is used to monitor the temperature of the motor and the converter.

7. A control method for a wind turbine tower gravity energy storage system, employing the method described in any one of claims 1-6, characterized in that, include: The real-time output power of the wind turbine main control system and the grid frequency are collected, and the target power setpoint and the tower natural frequency are combined to calculate the grid power deviation and grid frequency deviation. Determine whether the power grid frequency deviation is greater than a preset frequency deviation range. If so, execute the inertia support mode; otherwise, execute the energy balance control mode. The inertia support mode is as follows: execute a lifting action consistent with the frequency deviation of the power grid, determine the power command by calling a preset frequency deviation and lifting power mapping table, and execute the first operation; The energy balance control mode is as follows: if the power deviation of the grid is greater than the power deviation threshold, the energy storage quality module is controlled to rise to absorb redundant energy as the control result of the wind turbine tower gravity energy storage system; otherwise, the energy storage quality module is controlled to descend to release energy as the control result of the wind turbine tower gravity energy storage system. The first operation is to constrain the rise and fall rate of the power command based on the filtering algorithm of the tower's natural frequency until the grid frequency deviation recovers to the preset frequency deviation range, and then execute the energy balance control mode.

8. The control method for a wind turbine tower gravity energy storage system according to claim 7, characterized in that, The method further includes: Based on the mapping table between the frequency deviation and the power increase / decrease, the inertia response coefficient is dynamically adjusted according to the power grid frequency deviation; Determine whether the inertial response coefficient is less than or equal to an inertial response coefficient threshold. If so, the inertial response coefficient is set to 0.5-1Hz. -1 The frequency deviation and the rise / fall power command output by the mapping table of rise / fall power are corrected by the inertia response coefficient; otherwise, the inertia response coefficient is taken as 1-2Hz. -1 The frequency deviation and the power increase / decrease command output by the mapping table of power increase / decrease are corrected by the inertia response coefficient.

9. An electronic device, characterized in that, include: One or more processors; Storage device, on which one or more programs are stored, When the one or more programs are executed by the one or more processors, the one or more processors cause the one or more processors to implement the method as described in any one of claims 7-8.

10. A computer-readable storage medium, characterized in that, It stores a computer program thereon, wherein the computer program, when executed by one or more processors, implements the method as described in any one of claims 7-8.

Images