Gravity energy storage device for new energy power generation system

Abstract

The invention provides a gravity energy storage device for a new energy power generation system, and the gravity energy storage device comprises a control system and a plurality of energy storage working units connected with the control system, each energy storage working unit comprises a rack, a transmission shaft located in the rack, a first transmission, a flywheel, a power generation motor and a plurality of mechanical transmission modules, the gravity modules are arranged in a matched mode, and the well is located outside the rack. The transmission shaft is rotatably connected with the machine frame, each gravity module is connected with the transmission shaft through a corresponding mechanical transmission module and evenly distributed around the transmission shaft in a cylindrical spiral shape, each gravity module comprises a heavy object and a suspension mechanism which are connected, and each heavy object is located in a corresponding well. According to the invention, large-capacity and multi-mode energy storage and release can be realized, the gravity energy storage device not only can ensure that electric energy can still be stably generated under the condition that new energy continuously changes, but also can meet the requirement that the electric energy released by the gravity energy storage device by a main power grid can continuously change, and the energy storage density is large and the integration degree is high.

Description

Technical Field

[0001] The present invention belongs to the technical field of wind power generation and kinetic energy storage, and in particular relates to a gravity energy storage device for a new energy power generation system. Background Art

[0002] Wind and solar energy are both renewable energy sources. Since they come from nature, they will not be exhausted. This characteristic makes wind power generation and photovoltaic power generation a good choice for sustainable power supply. Compared with fossil fuel power generation, wind power generation and photovoltaic power generation can significantly reduce the emission of carbon dioxide and other greenhouse gases, which helps to mitigate the impact of global warming. However, affected by natural and technical factors, wind power generation and photovoltaic power generation are intermittent, random, and poorly dispatchable, which will cause a series of power quality problems. First, when wind power generation and photovoltaic power generation are affected by weather and the output power fluctuates, it will cause voltage fluctuations on the wind farm transmission line, and then cause grid voltage fluctuations; when the output power of the wind power generation system is large, flicker will also occur. Secondly, since the output of wind power generation and photovoltaic power generation is somewhat random, as the proportion of these two new energy sources in the total power generation of the power grid continues to increase, there may be frequency fluctuations in the power grid, which will have a bad impact on the power system and its users. In addition, since wind power generation and photovoltaic power generation both use a large number of power electronic equipment, they will generate a large number of harmonics and DC components. After harmonics are injected into the power system, they will cause voltage distortion in the power grid system and affect the power quality of the entire power grid system. When the proportion of these two new energy sources is not large, the above defects can be controlled within the range allowed by the power grid through modern power electronics technology; when these two new energy sources are connected to the grid on a large scale, it will have a great impact on the power system. The power grid must control the access to the two new energy generation capacity within a controllable range to minimize the adverse effects. This not only greatly limits the construction scale and development speed of these two new energy sources, but also leads to coal-fired power plants that are more environmentally damaging and have a higher proportion of carbon emissions as the main power generation. In order to ensure the smooth operation of the power grid, part of the power generation capacity of these two new energy sources is often abandoned in vain, so that new energy power stations cannot obtain the expected investment benefits. To this end, measures have been taken to develop and promote new energy storage technologies and supporting new energy storage power stations to reduce the waste of new energy and improve the utilization rate of new energy, thereby achieving social energy conservation and environmental protection. Secondly, new energy storage technologies can improve the reliability and stability of energy. Since energy storage power stations using new energy storage technologies require large capital investments, they currently play three main roles: First, balancing electricity supply and demand. Energy storage power stations can store electricity when electricity demand is low to balance electricity supply and ensure the stability of the power network, which helps reduce the risk of power outages and improve the reliability of the power system. Second, integrating renewable energy: Renewable energy such as wind and solar energy is volatile. Energy storage power stations can capture and store excess electricity to provide electricity during unstable periods. Third, frequency regulation and backup power supply. Energy storage power stations can be used as frequency regulation equipment for the power system to quickly respond to fluctuations in electricity demand.However, this cannot completely eliminate the above-mentioned adverse effects of these two types of renewable energy on the power grid. For the stability of the entire power grid and high power quality, renewable energy can only occupy a small share in the power supply. Traditional power generation methods based mainly on coal-fired power generation are still the main means of power generation because the power generation process is fully controllable and the power quality is excellent. This is contrary to the original intention of vigorously developing renewable energy.

[0003] When the new energy power generation system needs energy storage, the gravity energy storage device uses the motor to do work, lifts the heavy objects to a high place, and converts the electrical energy into gravitational potential energy; when the main power grid needs electrical energy, the heavy objects are used to do work to drive the generator to rotate, thereby converting the gravitational potential energy into electrical energy. The gravity energy storage device has the advantages of safety, fast response, large energy storage capacity, and long life. In order to generate electricity for a long time, the more common way is to build a high-height (generally about 120m) energy storage tower, steel structure or reinforced concrete structure frame on the ground, put down the heavy blocks stored at a high place one by one, and use the gravity of the heavy blocks to drive the generator to rotate and generate electricity, thereby converting the gravitational potential energy into electrical energy. This method requires continuous acquisition and release of heavy objects, high action accuracy requirements, and certain uncertainties; after the heavy objects are released to the upper or lower floors, they need to be reasonably arranged and placed to accommodate more heavy objects and maximize energy storage or release, which puts extremely high demands on the operation of computer hardware and software, control units and actuators; in addition, the construction of high-height energy storage towers or structural frames is labor-intensive, time-consuming, and costly.

[0004] In order to achieve the reuse of resources, gravity energy storage devices have been constructed using abandoned oil and gas wells, water towers or mines. However, these devices have low energy density and are limited by the distance from the location of new energy power generation. They cannot serve as supporting energy storage devices for new energy power plants in all regions, and cannot even store excess electricity from new energy. As a result, gravity energy storage devices are not widely used. Summary of the invention

[0005] The present disclosure aims to solve one of the technical problems in the related art at least to some extent.

[0006] To this end, the present disclosure provides a gravity energy storage device, which adopts the method of densely drilling dry wells near new energy (wind or photovoltaic) power plants to construct a well group, and forms energy storage working units by installing gravity energy storage equipment on multiple wells. Multiple energy storage working units and a control system constitute a gravity energy storage device, which realizes large-capacity and multiple ways of energy storage and energy release, with high energy storage density and high integration. The present disclosure connects the above-mentioned gravity energy storage device between the existing wind or photovoltaic power generation system and the main power grid, so that the electric energy generated by the wind or photovoltaic power generation system does not directly enter the main power grid, but is absorbed by the gravity energy storage device; when the main power grid needs electric energy, the above-mentioned gravity energy storage device releases energy, and the energy release process of the gravity energy storage device is controllable throughout, which solves the technical problems caused by the instability of the above-mentioned two new energy power generation. At the same time, in order to establish a power supply pattern based on new energy power generation, explore the possibility of using coal-fired power plants as backup power sources and thus significantly reduce carbon dioxide emissions.

[0007] In order to achieve the above objectives, the present disclosure adopts the following technical solutions:

[0008] The present disclosure provides a gravity energy storage device for a new energy power generation system, comprising a control system and a plurality of energy storage working units, each of which is connected to the control system via a control cable;

[0009] The energy storage working unit comprises a frame, a transmission shaft, a first transmission, a flywheel, a generator motor and several mechanical transmission modules located in the frame, as well as several supporting gravity modules and a well located outside the frame; the transmission shaft is rotatably connected to the frame, each gravity module is connected to the transmission shaft through a corresponding mechanical transmission module and is evenly distributed around the transmission shaft in a cylindrical spiral shape, each gravity module comprises a connected weight and a suspension mechanism, and each weight is located in a corresponding well; the low-speed shaft of the first transmission is connected to the transmission shaft through a first clutch, the high-speed shaft of the first transmission is connected to the generator motor through an elastic coupling, the flywheel is sleeved on the high-speed shaft of the first transmission, the generator motor is connected to the power cable of the new energy power generation system through a power cable, and the depth of the weight in the corresponding well is changed by the suspension mechanism to realize energy storage and energy release;

[0010] The control system is used to open or close a corresponding number of the energy storage working units according to the energy storage capacity requirements or energy release capacity requirements of the new energy power generation system, and to control and monitor the equipment status in each energy storage working unit.

[0011] In some embodiments, the frame as a whole is a box-type shell, the inner wall cross-section of the frame is a symmetrical polygonal structure, and the axis of the transmission shaft coincides with the central axis of the polygonal structure.

[0012] In some embodiments, the number of sides of the polygon is n, n is 4 to 8, the angle between each two adjacent elastic modules in the same energy storage working unit is 360° / n, the number of the energy storage devices arranged in a single energy storage working unit is n to 12n; the outer contour dimensions of the rack are consistent with the outer dimensions of a standard container.

[0013] In some embodiments, each well in the energy storage working unit is a dry well, which is a waterless well with a depth of more than 100 meters drilled by dense drilling near a new energy power station and formed after completion. The distance between two adjacent wells is 1.5 to 15 meters.

[0014] In some embodiments, the suspension mechanism includes a wire rope, a fixed pulley, a drum, a drum shaft, a drum support and a brake; one end of the wire rope is fixedly connected to the top of the weight, and the other end passes around the fixed pulley located above the wellhead and passes through a rope hole opened on the side wall of the frame on one side of the wellhead and then is wound around the drum located in the frame; the drum is fixedly sleeved on the drum shaft, and the drum shaft is rotatably connected to the drum support fixed on the inner wall of the frame through a bearing; the brake is sleeved on one end of the drum coaxially, and the brake brakes the drum coaxially under the control of the control system through the control cable, thereby changing the depth of the weight in the well; the other end of the drum shaft is connected to the mechanical transmission module.

[0015] In some embodiments, the mechanical transmission module includes a second clutch, a clutch bracket, a first synchronous toothed pulley, a synchronous toothed belt, a second synchronous toothed pulley and a one-way overrunning clutch; the second clutch is connected to the drum shaft, the second clutch and the first synchronous toothed pulley are fixedly connected to the frame through the clutch bracket, the outer circle of the one-way overrunning clutch cooperates with the inner hole of the second synchronous toothed pulley, the inner hole of the one-way overrunning clutch is sleeved and connected to the transmission shaft, and the first synchronous toothed pulley and the second synchronous toothed pulley are connected by the synchronous toothed belt; when the gravity module is fully loaded to store energy or the gravity module is no longer needed to continue to work on the transmission shaft, the second clutch is controlled by the control system to disengage from the drum shaft in the gravity module.

[0016] In some embodiments, the energy storage working unit further includes two auxiliary frames with the same structure, the two auxiliary frames are symmetrically arranged on both sides of the frame and rigidly connected to the frame as a whole, and the fixed pulley is supported on the corresponding auxiliary frames.

[0017] In some embodiments, the gravity module also includes a load stabilizer, which is arranged on one end of the drum shaft where the brake is provided, and eliminates the influence of the gravity change of the wire rope in the well on the torque of the generator motor by absorbing and releasing elastic potential energy; the load stabilizer includes a second transmission and a vortex spring box provided with a vortex spring, the high-speed shaft of the second transmission is connected to one end of the drum shaft, and the low-speed shaft of the second transmission is connected to the vortex spring in the vortex spring box, and the vortex spring box gradually changes the torque attached to the drum according to a linear law.

[0018] In some embodiments, the mechanical transmission module adopts a synchronous toothed belt transmission method, a sprocket chain transmission method or a gear transmission method to realize the mechanical transmission between the transmission shaft and the gravity module.

[0019] In some embodiments, the control system includes an operation controller and a sensing unit, a grid-connected control unit, a safety protection unit, a monitoring unit, a communication interface circuit and a user interface connected thereto; the sensing unit includes a depth sensor and a speed sensor, which are used to detect the depth of the weight in the well and the speed of the generator motor respectively; the grid-connected control unit is used to connect the electric energy generated by the gravity energy storage device to the main power grid; the safety protection unit is used to deal with emergencies, and when the parameters exceed the preset working range, the energy storage working unit with problems, or even all energy storage working units, are shut down in time; the monitoring unit is used to monitor the working status of the energy storage working unit in real time and transmit the data to the operation controller, the safety protection unit and the user interface; the communication interface circuit is used to realize data communication; the user interface is used to input user instructions, change parameters, and display the operating status, data and fault conditions of the gravity energy storage device; the operation controller is used for operation monitoring of the gravity energy storage device, including start and stop control of the energy storage working unit, control of various electronic devices and grid monitoring.

[0020] In some embodiments, the control system controls the working mode of each energy storage working unit according to the energy storage and release instructions of the new energy power generation system: when the new energy power generation site generates less power, the control system starts a single or a few of the energy storage working units to participate in energy storage; when the power generation site generates close to full load, the control system starts all the energy storage working units to participate in energy storage at the same time; when the power generation site generates more power, the control system starts a single or multiple energy storage working units to participate in energy storage one after another.

[0021] In some embodiments, the operation process of the gravity energy storage device includes:

[0022] During energy storage operation: the control system opens a corresponding number of energy storage working units according to the energy storage capacity requirements of the new energy power generation system. In the opened energy storage working units, the control system first starts the suspension mechanism and mechanical transmission module corresponding to the first well, and then connects the power cable to start the generator motor, and uses the suspension mechanism to lift the heavy object at the lower predetermined depth of the well or that has not reached the upper predetermined depth of the well; when the heavy object reaches the upper predetermined depth of the adjacent well, the control system first brakes the suspension mechanism and disconnects the suspension mechanism from the mechanical transmission module, and at the same time, the control system connects the suspension mechanism of the second well with the mechanical transmission module, and then lifts the heavy object in the second well, and follows the same operation until all the heavy objects in multiple wells of the energy storage working unit are lifted. When it is lifted to a predetermined depth at the top of the well, the control system disconnects the power cable and brakes the generator motor to realize the conversion of electrical energy into the gravitational potential energy of the weight and store it; if there is still surplus electrical energy to be stored, the control system activates other energy storage working units that have not yet achieved full-load energy storage, and when all energy storage working units store energy at full load, the energy storage operation ends; when a single or part of the energy storage working units are in the process of storing energy and unexpectedly have no energy storage capacity, the control system disconnects the power cable and brakes the generator motor, and at the same time brakes all the suspension mechanisms, so that the weight in the well is suspended at the current position, and the energy storage operation is suspended. If there is a subsequent energy storage requirement, the energy storage working unit whose energy storage operation is suspended continues the energy storage operation, and finally the gravity energy storage device stores energy at full load;

[0023] During the energy release operation: the control system opens a corresponding number of energy storage working units according to the energy release capacity of the new energy power generation system. In the opened energy storage working units, the control system first connects the power cable to start the generator motor, and then releases the brake on the suspension mechanism of the first well. The weight continues to descend in the well due to gravity. At the same time, the suspension mechanism drives the transmission shaft to rotate through the mechanical transmission module. The transmission shaft drives the generator motor to rotate and generate electricity after the speed is increased by the first transmission, thereby converting the gravitational potential energy into electrical energy. When the weight reaches the predetermined depth at the bottom of the adjacent well, the control system disconnects the suspension mechanism from the mechanical transmission module, brakes the suspension mechanism corresponding to the first well, and releases the brake on the suspension mechanism corresponding to the second well. The weight, under the action of gravity, passes through the suspension mechanism, mechanical transmission module, transmission shaft and first transmission, and continuously drives the generator motor to rotate, and follows the same operation until all the weights of the energy storage working unit descend to the predetermined depth at the bottom of the well, thereby realizing full-load energy release of the energy storage working unit; when the energy storage working unit is in the process of releasing energy and unexpectedly there is a situation where energy release is not required, the control system first disconnects the power cable, brakes the generator motor, and at the same time brakes the suspension mechanism that is releasing energy, so that the weight in the well is suspended at the current position, and the energy release operation is suspended; if there is a subsequent energy release requirement, the energy storage working unit whose energy release operation is suspended continues to release energy until the weight reaches the predetermined depth at the bottom of the well, thereby realizing full-load energy release of the energy storage working unit, and finally realizing full-load energy release of the gravity energy storage device.

[0024] The present disclosure has the following characteristics and beneficial effects:

[0025] The present disclosure adopts the method of densely drilling wells near the new energy power station to construct a well group, and constructs an energy storage working unit by installing energy storage equipment in multiple wells, and multiple energy storage working units form a gravity energy storage device through control cables and control systems, which can realize large-capacity and multiple ways of energy storage and energy release. Specifically, the energy storage capacity of each gravity energy storage device can store the electric energy generated by the corresponding wind farm or photovoltaic power plant at full load within a certain period of time. During the period when the output of the wind farm or photovoltaic power plant decreases or has no output due to natural reasons, the energy storage working unit in the gravity energy storage device continues to generate electricity stably within a certain period of time and supplies power to the main power grid stably; in the gravity energy storage device, a single energy storage working unit can store or release energy, and all energy storage working units can also participate in energy storage or release at the same time, which not only realizes that the wind farm can still store energy in the case of light wind and changing wind speed or the photovoltaic power plant can store energy in the case of low-intensity light or changing light intensity, but also meets the main power grid's requirement that the power supply of the gravity energy storage device can change at any time. More importantly, wind farms or photovoltaic power plants do not supply electricity directly to the main power grid, but instead generate electricity and connect to the grid through gravity energy storage devices, thus fundamentally solving the adverse effects of wind or photovoltaic power generation on the main power grid and creating conditions for increasing the proportion of these two types of renewable energy power generation in the power grid. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of the layout of a gravity energy storage device for a new energy power generation system provided by an embodiment of the present disclosure;

[0027] Figure 2 yes Figure 1 A schematic top view of the energy storage working unit shown;

[0028] Figure 3 yes Figure 2 A side cross-sectional schematic diagram of the energy storage working unit shown;

[0029] Figure 4 yes Figure 2 A schematic diagram showing a weight in a single energy storage working unit of the gravity energy storage device reaching an upper predetermined depth and a lower predetermined depth in a well;

[0030] Figure 5 yes Figure 2 A schematic side view of the internal structure of a load stabilizer in a gravity energy storage unit is shown;

[0031] Figure 6 yes Figure 1 A schematic diagram of the structure of the control system in the gravity energy storage device shown;

[0032] Reference numerals:

[0033] 100-energy storage working unit, 110-suspension mechanism, 111-reel bracket, 112-reel, 113-weight, 114-fixed pulley, 115-wire rope, 116-brake, 117-reel shaft, 118-load stabilizer, 118a-vortex spring box, 118b-second transmission, 121-well, 122-auxiliary frame, 123-frame, 130-mechanical transmission module, 131-second clutch, 132-clutch bracket, 133-first synchronous toothed pulley, 134-synchronous toothed belt, 135-second synchronous toothed pulley, 136-one-way overrunning clutch, 140-transmission shaft, 141-first bearing, 150-first clutch, 160-first transmission, 170-flywheel, 180-elastic coupling, 190-generator motor, 191-power cable;

[0034] 200-control cable;

[0035] 300 - control system, 310 - sensing unit, 311 - depth sensor, 312 - rotation speed sensor, 320 - operation controller, 330 - grid-connected control unit, 340 - safety protection unit, 350 - monitoring unit, 360 - communication interface circuit, 370 - user interface. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0037] On the contrary, the present application covers any substitution, modification, equivalent method and scheme made on the essence and scope of the present application as defined by the claims. Further, in order to make the public have a better understanding of the present application, some specific details are described in detail in the detailed description of the present application below. Those skilled in the art can fully understand the present application without the description of these details.

[0038] In the description of the present disclosure, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present disclosure and simplifying the description, rather than indicating or implying that the basis or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present disclosure. In addition, the terms "first" and "second" are used only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present disclosure, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0039] In the description of the present disclosure, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present disclosure can be understood according to specific circumstances.

[0040] In the present disclosure, unless otherwise expressly specified and limited, a first feature being “above” or “below” a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being “above”, “above”, and “above” a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being “below”, “below”, and “below” a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0041] See also Figure 1 to Figure 6 , a gravity energy storage device for a new energy power generation system provided by an embodiment of the present disclosure includes: a plurality of energy storage working units 100 and a control system 300, each energy storage working unit 100 is connected to the control system 300 through a control cable 200;

[0042] The energy storage working unit 100 includes a frame 123, a transmission shaft 140 located in the frame 123, a first transmission 160, a flywheel 170, a generator motor 190 and a plurality of mechanical transmission modules 130, as well as a plurality of supporting gravity modules and a well 121 located outside the frame 123; the transmission shaft 140 is rotatably connected to the frame 123, each gravity module is connected to the transmission shaft 140 through a corresponding mechanical transmission module 130 and is evenly distributed in a cylindrical spiral around the transmission shaft 140, and each gravity module includes a connected weight 1 13 and a suspension mechanism 110, each weight 113 is respectively located in a corresponding well 121; the low-speed shaft of the first transmission 160 is connected to the transmission shaft 140 through the first clutch 150, the high-speed shaft of the first transmission 160 is connected to the generator motor 190 through the elastic coupling 180, the flywheel 170 is sleeved on the high-speed shaft of the first transmission 160, the generator motor 190 is connected to the power cable of the new energy power generation system through the power cable 191, and the height of the weight 113 in the corresponding well 121 is changed by the suspension mechanism 110 to realize energy storage and energy release;

[0043] The control system 300 is used to open or close a corresponding number of energy storage working units 100 according to the energy storage capacity requirement or energy release capacity requirement of the new energy power generation system, and to control and monitor the equipment status in each energy storage working unit 100.

[0044] Furthermore, the control system 300 controls the working mode of each energy storage working unit 100 according to the energy storage and release instructions of the new energy power generation system: when the new energy power generation site has less power generation, the new energy power generation system instructs the control system 300 of the gravity energy storage device to start a single or a few energy storage working units 100 to participate in energy storage; when the power generation site is close to full load, the new energy power generation system instructs the control system 300 to start all energy storage working units 100 to participate in energy storage at the same time; when the power generation site is gradually increasing, the control system 300 starts a single or a group of energy storage working units 100 to participate in energy storage one after another.

[0045] In some embodiments, the number of energy storage working units 100 can be 3 or more, or even hundreds, to achieve full absorption of new energy (such as wind power and photovoltaic) power generation, and also to meet the power supply needs of the main power grid through long-term stable energy release when new energy power generation is insufficient.

[0046] In some embodiments, see Figures 1 to 5In a single energy storage working unit 100, several groups of gravity modules and mechanical transmission modules 130 are included. Each group of gravity modules and mechanical transmission modules 130 constitutes an energy storage device, which can work on the transmission shaft 140 alone or together with other multiple energy storage devices. The control system 300 can adjust the speed of the transmission shaft 140 in real time by making gravity modules with different energy storage capacities and quantity combinations work on the transmission shaft 140, thereby achieving the requirement that the energy storage working unit 100 can generate electricity steadily within a certain power range. The structures of the energy storage working units 100 are the same, and one of the energy storage working units 100 is now taken as an example for explanation.

[0047] See also Figure 2 , 3 The frame 123 is a box-type shell as a whole. The suspension mechanisms 110 and mechanical transmission modules 130 in the frame 123 are spatially distributed in a cylindrical spiral state along the transmission shaft 140. In order to facilitate the installation of the suspension mechanisms 110 and mechanical transmission modules 130 in the frame 123, improve the strength of the frame 123, and adapt to the arrangement of the suspension mechanisms 110 around the dense well group, thereby greatly improving the space utilization and energy storage density of the energy storage working unit 100, the inner wall cross section of the frame 123 is designed to be a symmetrical polygonal structure, the axis of the transmission shaft 140 coincides with the central axis of the polygonal structure, and the two ends of the transmission shaft 140 are rotatably connected to the frame 123 through the first bearing 141. In addition, the frame 123 with a symmetrical polygonal inner wall allows the mechanical transmission modules 130 in a single energy storage working unit 100 to adopt the same specifications, which is convenient for organizing production. Assume that the number of sides of the polygon of the inner wall of the frame 123 is n, and n is preferably 4 to 8. The angle between each adjacent two suspension mechanisms 110 in a single energy storage working unit 100 is 360° / n, and the number of energy storage devices provided in a single energy storage working unit 100 is preferably n to 12n. In this embodiment, the cross section of the inner wall of the frame 123 is a symmetrical hexagonal structure, and the angle between each adjacent two gravity modules is 60°.

[0048] Furthermore, the outer dimensions of the rack 123 are consistent with those of a standard container to meet transportation requirements.

[0049] Each well 121 in the energy storage working unit 100 is a dry well, which is a waterless well formed after completion by drilling a hole with a depth of more than 100 meters in a densely drilled area near a new energy power station and in an area with deep groundwater and rock formations. The so-called dense drilling means that the well spacing is smaller than that of normal drilling. On a plot with multiple wells, the well spacing between two adjacent wells is 1.5 to 15 meters.

[0050] See also Figure 2 to Figure 4 (It should be noted that Figure 3Only one of the suspension mechanisms is shown in the figure, and the other suspension mechanisms are shown in the figure. Figure 3 (not shown), the structures of the gravity modules in the energy storage unit 100 are the same, and each of them includes a connected weight 113 and a suspension mechanism 110. Among them:

[0051] The weight 113 is suspended in the well 121 by the suspension mechanism 110. The weight 113 is required to be made of a material with a mass of more than 5,000 kg and an average density of more than 2,000 kg / m3. A safe distance should be reserved between the lowest and highest positions of the weight 113 in the well 121 and the well bottom and wellhead, respectively, to avoid damage to the well bottom when the weight 113 is lowered to the lowest position and to avoid damage to the facilities outside the well when the weight 113 is lifted to the highest position.

[0052] The suspension mechanism 110 includes a steel wire rope 115, a fixed pulley 114, a drum 112, a drum shaft 117, a drum support 111 and a brake 116. One end of the steel wire rope 115 is fixedly connected to the top of the weight 113, and the other end of the steel wire rope 115 passes through the fixed pulley 114 located above the wellhead and passes through the rope hole opened on the side wall of the frame 123 located on one side of the wellhead and then is wound on the drum 112 located in the frame 123. The drum 112 is fixedly sleeved on the drum shaft 117, and the drum shaft 117 is rotatably connected to the drum support 111 fixed on the inner wall of the frame 123 through a bearing. The brake 116 is sleeved on one end of the reel coaxial 117. The brake 116 brakes the reel coaxial 117 under the control of the control system 300 through the control cable 200, thereby changing the height of the weight 113 in the well 121; the other end of the reel shaft 117 is connected to the mechanical transmission module 130.

[0053] Furthermore, the brake 116 may be an electromagnetic power-off brake, a drum brake, a butterfly brake, or a tooth brake. The electromagnetic power-off brake is preferably used in this embodiment.

[0054] See also Figure 2Each mechanical transmission module 130 in the energy storage unit 100 includes a second clutch 131, a clutch bracket 132, a first synchronous toothed pulley 133, a synchronous toothed belt 134, a second synchronous toothed pulley 135 and a one-way overrunning clutch 136. The second clutch 131 is connected to the end of the drum shaft 117 in the suspension mechanism 110 away from the brake 116. The second clutch 131 and the first synchronous toothed pulley 133 are fixedly connected to the inner wall of the frame 123 through the clutch bracket 132. The outer circle of the one-way overrunning clutch 136 is matched with the inner hole of the second synchronous toothed pulley 135. The inner hole of the one-way overrunning clutch 136 is connected to the transmission shaft 140. The first synchronous toothed pulley 133 and the second synchronous toothed pulley 135 are connected through the synchronous toothed belt 134. The mechanical transmission module 130 connected to each gravity module can not only transmit the rotation of the transmission shaft 140 to the gravity module to raise the height of the weight 113 in the well 121, but also transmit the torque on the drum shaft 117 when releasing the weight 113 in the well 121 to the transmission shaft 140. Specifically, when energy storage is required, the transmission shaft 140 rotates the second synchronous toothed pulley 135 through the one-way overrunning clutch 136, the second synchronous toothed pulley 135 rotates the first synchronous toothed pulley 133 through the synchronous toothed belt 134, and the first synchronous toothed pulley 133 rotates the drum shaft 117 in the suspension mechanism 110 through the second clutch 131, so that the weight 113 in the well 121 is lifted; when the gravity module releases energy, the transmission route of the mechanical transmission module 130 is exactly opposite to that when storing energy. When the control system 300 brakes the suspension mechanism 110 in the gravity module that has fully stored energy, the second clutch 131 in the mechanical transmission module 130 will be disengaged from the reel shaft 117 to avoid damage to the mechanical transmission module 130; when the control system 300 does not need the gravity module to continue to work on the transmission shaft 140, the control system 300 will also disengage the second clutch 131 in the mechanical transmission module 130 from the reel shaft 117 to avoid the gravity module continuing to work on the transmission shaft 140, causing the speed of the transmission shaft 140 to lose control; the second clutch 131 generally adopts an electromagnetic friction clutch or an electromagnetic tooth clutch, and in this embodiment, an electromagnetic friction clutch is preferably used. The synchronous toothed belts 134 in each mechanical transmission module 130 in the same energy storage unit 100 are of the same size, which is conducive to standardized production.

[0055] Furthermore, the one-way overrunning clutch 136 is also called a one-way bearing, and can be a spherical, wedge-shaped or tooth-shaped one-way overrunning clutch. In this embodiment, a spherical one-way overrunning clutch is preferred.

[0056] It is understandable that the setting of the one-way overrunning clutch 136 in this embodiment can avoid the influence of the braking of one or more gravity modules on the continued operation of the transmission shaft 140 by the remaining gravity modules that are not braked. Specifically, when the energy release of the suspension mechanism 110 corresponding to the first well in the energy storage working unit is about to end, the energy release is switched to the second well. Due to the use of the one-way overrunning clutch 136, the mechanical transmission module 130 of the second well will not be affected by the deceleration of the mechanical transmission module of the first well or the braking of the suspension mechanism 110 of the first well, and in particular, the mechanical transmission module 130 corresponding to the suspension mechanism 110 that does not participate in the energy release will not cause the efficiency of the energy storage working unit 100 to decrease when releasing energy as the transmission shaft 140 idles. In addition, the mechanical transmission module 130 of this embodiment uses a first synchronous toothed pulley 133, a synchronous toothed belt 134 and a second synchronous toothed pulley 135 for transmission between the gravity module and the transmission shaft 140, that is, a synchronous toothed belt transmission method is adopted. This method has smooth transmission and does not cause loss of rotation; when the transmitted torque is large, a sprocket chain transmission method or a gear transmission method can be used instead of the synchronous toothed belt transmission method.

[0057] See also Figure 2 One end of the transmission shaft 140 in the energy storage unit 100 is connected to the low-speed shaft of the first transmission 160 through the first clutch 150, and the high-speed shaft of the first transmission 160 is connected with a flywheel 170. The high-speed shaft of the first transmission 160 is connected to the generator motor 190 through the elastic coupling 180, and the generator motor 190 is connected to the power cable of the new energy power generation system through the power cable 191; the control system 300 controls the connection and disconnection of the power cable 191, and controls the connection of the excitation winding current and voltage in the generator motor 190 and the start and stop of the electromagnetic brake device. The first transmission 160 can be a planetary transmission or other types of transmissions.

[0058] Further, see Figure 2 and Figure 3 Each energy storage working unit 100 also includes two auxiliary frames 122 of the same structure, which are symmetrically arranged on both sides of the frame 123 and rigidly connected to the frame 123 as a whole. The auxiliary frames 122 are used to support the fixed pulley 114 in the suspension structure 110. By symmetrically installing the auxiliary frames 122 on both sides of the frame 123, the pulling force of the weight 113 on the frame 123 through the steel wire rope 115 can be balanced. By rigidly connecting the frame 123 and the auxiliary frames 122 as a whole, the requirements for the ground foundation can be reduced. There is no need to cast a solid reinforced concrete foundation for the suspension mechanism 110 to withstand the pulling force of the weight 113 through the steel wire rope 115. By prefabricating the frame 123 and the auxiliary frames 122 in the factory, the construction period of the construction site can be greatly shortened, reducing the on-site construction cost.

[0059] Further, see Figure 2 , Figure 3 , Figure 5Considering that the heavy object 113 descends, the wire rope 115 in the well 121 gradually becomes longer, the gravity of the wire rope 115 gradually increases, and the torque added to the drum 112 by the gravity of the wire rope 115 gradually increases, thereby increasing the additional torque on the generator motor 190. Therefore, a load stabilizer 110 is provided at one end of the drum shaft 117 where a brake 116 is provided. The load stabilizer 118 eliminates the influence of the gravity change of the wire rope 115 in the well 121 on the torque of the generator motor 190 by absorbing and releasing elastic potential energy. The load stabilizer 118 includes a vortex spring box 118a with a vortex spring and a second transmission 118b. One end of the drum shaft 117 with a brake 116 is connected to the high-speed shaft of the second transmission 118b, and is transmitted to the vortex spring box 118a after being decelerated by the second transmission 118b. The vortex spring box 118a gradually reduces the torque on the drum 112 in a linear law, so that the torque acting on the drum 112 remains constant, and the torque acting on the generator motor 190 remains constant. Specifically: when the wire rope 115 starts to move from the wellhead to the wellhead with the weight 113, the wire rope 115 is connected to the high-speed shaft of the second transmission 118b. When the well bottom descends, the torque of the wire rope 115 attached to the drum 112 gradually increases, the vortex spring in the vortex spring box 118a is in the process of relaxation, and the torque attached to the drum 112 gradually decreases; when the lower end of the wire rope 115 descends to the well bottom with the weight 113, the torque of the wire rope 115 attached to the drum 112 is the largest, and the torque of the vortex spring in the vortex spring box 118a attached to the drum 112 is the smallest, which offsets the effect of the increased gravity of the wire rope 115, so that the torque of the generator motor 190 driven by the descending weight 113 remains basically constant.On the contrary, when the weight 113 rises, the wire rope 115 in the well 121 gradually becomes shorter, the gravity of the wire rope 115 gradually decreases, and there is a trend that the torque attached to the drum 112 by the wire rope 115 gradually decreases. One end of the drum shaft 117 is connected to the high-speed shaft of the second transmission 118b, which is transmitted to the vortex spring box 118a after deceleration through the second transmission 118b. The vortex spring box 118a is tightened and gradually increases the torque on the drum 112 in a linear law, so that the torque acting on the drum 112 remains constant, and the torque acting on the generator motor 190 remains constant. Specifically: when the lower end of the wire rope 115 starts to rise from the bottom of the well with the weight 113, the wire rope 115 attached to the drum The torque on the drum 112 is the largest, and the vortex spring in the vortex spring box 118a is in a relaxed state, the elastic potential energy stored in the vortex spring box 118a is the smallest, and the torque attached to the drum 112 is also the smallest; when the wire rope 115 rises to near the wellhead with the weight 113, the torque attached to the drum 112 by the wire rope 115 is the smallest, and the vortex spring in the vortex spring box 118a in the negative stabilizer 118 is continuously tightened by the drum shaft 117 during the rising process of the weight 113, and the elastic potential energy stored becomes the largest, and the torque attached to the drum 112 is the largest, which offsets the effect of the reduced gravity of the wire rope 115, so that the torque of the generator motor 190 is always constant during the process of lifting the weight 113. Optionally, the vortex spring box 118a adopts a vortex spring with linear characteristics, and the vortex spring elastic force F=kx, where k is the elastic coefficient of the vortex spring, and x is the deformation of the vortex spring. The second transmission 118b adopts a two-stage planetary transmission. The advantage is that the input shaft and the output shaft remain on the same axis, which has a higher efficiency. In addition: when the outer gear ring of the planetary transmission is fixed, the two-stage speed increase ratio of the planetary wheel carrier shaft and the sun wheel shaft can reach 1:50, and the vortex spring can generally be rotated 30 times from the shaft rotation to the tightening direction, so that the drum 112 can rotate 1500 times through the speed increase ratio, which is fully adapted to the state in which the torque attached to the drum 112 by its gravity changes linearly with a smaller slope when the wire rope 115 is unfolded.

[0060] In some embodiments, see Figure 1 to Figure 6The control system 300 includes a sensing unit 310, an operation controller 320, a grid-connected control unit 330, a safety protection unit 340, a monitoring unit 350, a communication interface circuit 360, and a user interface 370. The sensing unit 310 includes a depth sensor 311 and a speed sensor 312. The depth sensor 311 is arranged beside the wellhead and is used to detect the depth of the weight 113 in the well. A laser rangefinder can be used to measure the depth of the weight 113 using the laser rangefinder principle. The speed sensor 312 is connected to the rotating shaft of the generator motor 190 and is used to collect the speed of the generator motor 190. The grid-connected control unit 330 is used to connect the electric energy generated by the gravity energy storage device to the main power grid. The safety protection unit 340 is used to deal with emergencies. When the parameters exceed the preset working range, the energy storage working unit 100 with problems is shut down in time, or even the entire gravity energy storage device. The monitoring unit 350 is used to monitor the working status of the energy storage working unit 100 in real time and transmit the data to the operation controller 320, the safety protection unit 340, and the user interface 370. The communication interface circuit 360 is used to control the data communication between the system 300 and the energy storage working unit 100. The user interface 370 is used to input user instructions, change parameters, and display the operating status, data, and faults of the gravity energy storage device; the human-computer interaction and display functions of the user interface 370 are realized through the computer user display system and the real-time tracing system. As the center of the control system 300, the operation controller 320 is connected to the sensor unit 310, the grid-connected control unit 330, the safety protection unit 340, the monitoring unit 350, the communication interface circuit 360 and the user interface 370 to perform operation monitoring, including the start and stop of the energy storage working unit, the control of other functional modules, and the monitoring of the power grid; the operation controller 320 mainly realizes these functions through a programmable controller. In addition, the operation controller 320 of the control system 300 is connected to the depth sensor 311 and the speed sensor 312 that need to be controlled in the energy storage working unit 100 through the control cable 200, and is also connected to the brake 116, the first clutch 150, the second clutch 131 and the generator motor 190 to realize the control of the working mode of the energy storage working unit 100 and the monitoring of the working status.

[0061] In some embodiments, the operation process of the gravity energy storage device provided in the embodiments of the present disclosure includes:

[0062] During energy storage operation: the control system 300 opens a corresponding number of energy storage working units 100 according to the energy storage capacity required by the new energy power generation system. In the opened energy storage working units 100, the operation controller 320 in the control system 300 first controls the brake 116 in the suspension mechanism 110 corresponding to the first well through the communication interface circuit 360 to release the brake on the drum 112, and at the same time connects the second clutch 131 to connect the suspension mechanism 110 with the mechanical transmission module 130, and then connects the power cable 191, and starts the generator motor 190 to rotate. The generator motor 190 reduces the speed through the first transmission 160, drives the drum 112 to rotate through the transmission shaft 140 and the mechanical transmission module 130, and the drum 112 changes direction through the steel wire rope 115 wound thereon with the help of the fixed pulley 114, and lifts the heavy object 113 at the predetermined depth at the bottom of the well 121 or has not yet reached the predetermined depth at the top of the well. When the weight 113 is lifted to a predetermined depth at the top of the well 121, the operation controller 320 in the control system 300 first disconnects the second clutch 131 in the mechanical transmission module 130 through the communication interface circuit 360, and at the same time controls the brake 116 in the brake suspension mechanism 110 to brake the reel 112, and at the same time starts to connect the suspension mechanism 110 of the second well 121, and so on, so that the suspension mechanisms 110 corresponding to multiple wells 121 in the energy storage working unit 100 complete the energy storage action in turn, and finally realize the full energy storage of the energy storage working unit 100; if there is still surplus electric energy to be stored, the control system 300 opens the remaining energy storage working units 100 until the weight 113 in all the energy storage working units 100 in the entire gravity energy storage device is lifted to the predetermined depth at the top of the well 121, and full-load energy storage is realized. When a single or part of the energy storage working unit 100 is in the process of storing energy and unexpectedly has no energy storage capacity, the control system 300 disconnects the power cable 191, brakes the generator motor 190, and then controls the brake 116 to brake the drum 112, so that the weight 113 in the well is suspended at the current position, and the energy storage operation is suspended. If there is a subsequent energy storage requirement, the energy storage working unit 100 whose energy storage operation is suspended can continue the energy storage operation until the weight 113 reaches the predetermined depth at the top of the well, so as to achieve full-load energy storage of the energy storage working unit 100, and then achieve full-load energy storage of the gravity energy storage device.

[0063] During the energy release operation: the control system 300 activates a corresponding number of energy storage working units 100 according to the energy release capacity required by the new energy power generation system. In the activated energy storage workstation 100, the operation controller 320 in the control system 300 first connects the power cable 191 through the communication interface circuit 360, and then starts the generator motor 190, and at the same time controls the brake 116 in the suspension mechanism 110 corresponding to the first well to release the brake on the reel 112, and at the same time closes the second clutch 131 in the mechanical transmission module 130. The weight 113 pulls the wire rope 115, which changes direction with the help of the fixed pulley 114 and pulls the drum 112 of the suspension mechanism 110 in the frame 123 to rotate. The drum 112 transmits the motion to the mechanical transmission module 130 through the drum shaft 117, which in turn drives the transmission shaft 140 to rotate. The transmission shaft 140 rotates the low-speed shaft of the first transmission 160 through the first clutch 150, and the first transmission 160 increases the speed and drives the generator motor 190 to rotate and generate electricity. During the rotation process of the drum 112, the weight 113 is continuously lowered by releasing the wire rope 115. When the weight 113 is at a predetermined depth at the bottom of the well 121, the control system 300 disconnects the second clutch 131 in the mechanical transmission module 130 corresponding to the first well, and at the same time controls the brake 116 in the suspension mechanism 110 to brake the reel 112 in the suspension mechanism 110 corresponding to the first well, and at the same time connects the suspension mechanism 110 and the mechanical transmission module 130 corresponding to the second well to continue to release energy, and so on, the gravitational potential energy stored in the suspension mechanisms 110 corresponding to all the wells 121 in the energy storage working unit 100 is released. During the energy release process, the flywheel 170 rotates with the high-speed shaft of the transmission 160 to avoid the influence of switching between the suspension mechanisms 110 on the operation of the generator motor 190. When all the suspension mechanisms 110 have finished releasing energy, the control system 300 disconnects the power cable 191 and then brakes the generator motor 190; if the gravity energy storage device still needs to release energy, the control system 300 activates the remaining energy storage working units 100 that have stored gravity energy release in the gravity energy storage device until the entire gravity energy storage device lowers the weights 113 in all the energy storage working units 100 to the predetermined depth at the bottom of the well 121, achieving full-load energy release. When a single or part of the energy storage working units 100 are in the process of releasing energy, and unexpectedly there is no need to release energy, the operation controller 320 of the control system 300 will disconnect the power cable 191 and brake the generator motor 190. The control system 300 also controls the brake 116 to brake the drum 112. Finally, the control system 300 controls the weight 113 in the well 121 to suspend at the current position, and the energy release operation is suspended. If there is a subsequent energy release requirement, the energy storage working unit 100 that has been suspended from releasing energy will continue to release energy until the weight 113 reaches the predetermined depth at the bottom of the well 121. The energy release operation of the energy storage working unit 100 is completed, and finally the full-load energy release of the gravity energy storage device is achieved.

[0064] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present disclosure. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0065] Although embodiments of the present disclosure have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions and alterations may be made to the embodiments without departing from the principles and spirit of the present disclosure, the scope of which is defined by the claims and their equivalents.

Claims

1. A gravity energy storage device for a new energy power generation system, characterized in that: It includes a control system and a plurality of energy storage working units, each of which is connected to the control system via a control cable; The energy storage working unit comprises a frame, a transmission shaft, a first transmission, a flywheel, a generator motor and several mechanical transmission modules located in the frame, as well as several supporting gravity modules and a well located outside the frame; the transmission shaft is rotatably connected to the frame, each gravity module is connected to the transmission shaft through a corresponding mechanical transmission module and is evenly distributed around the transmission shaft in a cylindrical spiral shape, each gravity module comprises a connected weight and a suspension mechanism, and each weight is located in a corresponding well; the low-speed shaft of the first transmission is connected to the transmission shaft through a first clutch, the high-speed shaft of the first transmission is connected to the generator motor through an elastic coupling, the flywheel is sleeved on the high-speed shaft of the first transmission, the generator motor is connected to the power cable of the new energy power generation system through a power cable, and the depth of the weight in the corresponding well is changed by the suspension mechanism to realize energy storage and energy release; The control system is used to open or close a corresponding number of the energy storage working units according to the energy storage capacity requirements or energy release capacity requirements of the new energy power generation system, and to control and monitor the equipment status in each energy storage working unit.

2. The gravity energy storage device according to claim 1, characterized in that: The frame as a whole is a box-type shell, the inner wall cross section of the frame is a symmetrical polygonal structure, and the axis of the transmission shaft coincides with the central axis of the polygonal structure.

3. The gravity energy storage device according to claim 2, characterized in that: Assume that the number of sides of the polygon is n, and n is 4 to 8. The angles between two adjacent elastic modules in the same energy storage working unit are 360° / n. The number of energy storage devices arranged in a single energy storage working unit is n to 12n. The outer contour dimensions of the rack are consistent with the outer dimensions of a standard container.

4. The gravity energy storage device according to claim 1, characterized in that: All the wells in the energy storage working unit are dry wells, which are waterless wells with a depth of more than 100 meters drilled by dense drilling near the new energy power station and formed after completion. The distance between two adjacent wells is 1.5 to 15 meters.

5. The gravity energy storage device according to claim 1, characterized in that: The suspension mechanism includes a wire rope, a fixed pulley, a drum, a drum shaft, a drum support and a brake; one end of the wire rope is fixedly connected to the top of the weight, and the other end passes around the fixed pulley located above the wellhead and passes through the rope hole opened on the side wall of the frame located on one side of the wellhead and then is wound around the drum located in the frame; the drum is fixedly sleeved on the drum shaft, and the drum shaft is rotatably connected to the drum support fixed on the inner wall of the frame through a bearing; the brake is sleeved on one end of the drum coaxial line, and the brake brakes the drum coaxial line under the control of the control system through the control cable, thereby changing the depth of the weight in the well; the other end of the drum shaft is connected to the mechanical transmission module.

6. The gravity energy storage device according to claim 5, characterized in that: The mechanical transmission module includes a second clutch, a clutch bracket, a first synchronous toothed belt pulley, a synchronous toothed belt, a second synchronous toothed belt pulley and a one-way overrunning clutch; the second clutch is connected to the drum shaft, the second clutch and the first synchronous toothed belt pulley are fixedly connected to the frame through the clutch bracket, the outer circle of the one-way overrunning clutch is matched with the inner hole of the second synchronous toothed belt pulley, the inner hole of the one-way overrunning clutch is sleeved and connected to the transmission shaft, and the first synchronous toothed belt pulley and the second synchronous toothed belt pulley are connected by the synchronous toothed belt; when the gravity module is fully loaded to store energy or the gravity module is no longer needed to continue to work on the transmission shaft, the second clutch is controlled by the control system to disengage from the drum shaft in the gravity module.

7. The gravity energy storage device according to claim 5, characterized in that: The energy storage working unit further comprises two auxiliary frames with the same structure, which are symmetrically arranged on both sides of the frame and rigidly connected to the frame as a whole, and the fixed pulley is supported on the corresponding auxiliary frames.

8. The gravity energy storage device according to claim 5, characterized in that: The gravity module also includes a load stabilizer, which is arranged on one end of the drum shaft where the brake is provided, and eliminates the influence of the gravity change of the wire rope in the well on the torque of the generator motor by absorbing and releasing elastic potential energy; the load stabilizer includes a second transmission and a vortex spring box provided with a vortex spring, the high-speed shaft of the second transmission is connected to one end of the drum shaft, and the low-speed shaft of the second transmission is connected to the vortex spring in the vortex spring box, and the vortex spring box gradually changes the torque attached to the drum according to a linear law.

9. The gravity energy storage device according to claim 1, characterized in that: The mechanical transmission module adopts a synchronous toothed belt transmission mode, a sprocket chain transmission mode or a gear transmission mode to realize the mechanical transmission between the transmission shaft and the gravity module.

10. The gravity energy storage device according to any one of claims 1 to 9, characterized in that: The control system includes an operation controller and a sensor unit, a grid-connected control unit, a safety protection unit, a monitoring unit, a communication interface circuit and a user interface connected thereto; the sensor unit includes a depth sensor and a speed sensor, which are used to detect the depth of the weight in the well and the speed of the generator motor respectively; The grid-connected control unit is used to connect the electric energy generated by the gravity energy storage device to the main power grid; the safety protection unit is used to deal with emergencies, and when the parameters exceed the preset working range, the energy storage working unit with problems, or even all energy storage working units, are shut down in time; the monitoring unit is used to monitor the working status of the energy storage working unit in real time, and transmit the data to the operation controller, the safety protection unit and the user interface; The communication interface circuit is used to realize data communication; the user interface is used to input user instructions, change parameters, and display the operating status, data and fault conditions of the gravity energy storage device; the operation controller is used to monitor the operation of the gravity energy storage device, including the start and stop control of the energy storage working unit, the control of various electronic devices and the power grid monitoring.

11. The gravity energy storage device according to claim 1, characterized in that: The control system controls the working mode of each energy storage working unit according to the energy storage and release instructions of the new energy power generation system: when the new energy power generation site generates less power, the control system starts a single or a few of the energy storage working units to participate in energy storage; when the power generation site generates close to full load, the control system starts all the energy storage working units to participate in energy storage at the same time; when the power generation site generates more power, the control system starts a single or multiple energy storage working units to participate in energy storage one after another.

12. The gravity energy storage device according to claim 1, characterized in that: The operation process of the gravity energy storage device includes: During energy storage operation: the control system opens a corresponding number of energy storage working units according to the energy storage capacity requirements of the new energy power generation system. In the opened energy storage working units, the control system first starts the suspension mechanism and mechanical transmission module corresponding to the first well, and then connects the power cable to start the generator motor, and uses the suspension mechanism to lift the heavy object at the lower predetermined depth of the well or that has not reached the upper predetermined depth of the well; when the heavy object reaches the upper predetermined depth of the adjacent well, the control system first brakes the suspension mechanism and disconnects the suspension mechanism from the mechanical transmission module, and at the same time, the control system connects the suspension mechanism of the second well with the mechanical transmission module, and then lifts the heavy object in the second well, and follows the same operation until all the heavy objects in multiple wells of the energy storage working unit are lifted. When it is lifted to a predetermined depth at the top of the well, the control system disconnects the power cable and brakes the generator motor to realize the conversion of electrical energy into the gravitational potential energy of the weight and store it; if there is still surplus electrical energy to be stored, the control system activates other energy storage working units that have not yet achieved full-load energy storage, and when all energy storage working units store energy at full load, the energy storage operation ends; when a single or part of the energy storage working units are in the process of storing energy and unexpectedly have no energy storage capacity, the control system disconnects the power cable and brakes the generator motor, and at the same time brakes all the suspension mechanisms, so that the weight in the well is suspended at the current position, and the energy storage operation is suspended. If there is a subsequent energy storage requirement, the energy storage working unit whose energy storage operation is suspended continues the energy storage operation, and finally the gravity energy storage device stores energy at full load; During the energy release operation: the control system opens a corresponding number of energy storage working units according to the energy release capacity of the new energy power generation system. In the opened energy storage working units, the control system first connects the power cable to start the generator motor, and then releases the brake on the suspension mechanism of the first well. The weight continues to descend in the well due to gravity. At the same time, the suspension mechanism drives the transmission shaft to rotate through the mechanical transmission module. The transmission shaft drives the generator motor to rotate and generate electricity after the speed is increased by the first transmission, thereby converting the gravitational potential energy into electrical energy. When the weight reaches the predetermined depth at the bottom of the adjacent well, the control system disconnects the suspension mechanism from the mechanical transmission module, brakes the suspension mechanism corresponding to the first well, and releases the brake on the suspension mechanism corresponding to the second well. The weight, under the action of gravity, passes through the suspension mechanism, mechanical transmission module, transmission shaft and first transmission, and continuously drives the generator motor to rotate, and follows the same operation until all the weights of the energy storage working unit descend to the predetermined depth at the bottom of the well, thereby realizing full-load energy release of the energy storage working unit; when the energy storage working unit is in the process of releasing energy and unexpectedly there is a situation where energy release is not required, the control system first disconnects the power cable, brakes the generator motor, and at the same time brakes the suspension mechanism that is releasing energy, so that the weight in the well is suspended at the current position, and the energy release operation is suspended; if there is a subsequent energy release requirement, the energy storage working unit whose energy release operation is suspended continues to release energy until the weight reaches the predetermined depth at the bottom of the well, thereby realizing full-load energy release of the energy storage working unit, and finally realizing full-load energy release of the gravity energy storage device.

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