Gravity energy storage system and control method

Abstract

The invention belongs to the technical field of energy power generation, and discloses a gravity energy storage system and a control method. The gravity energy storage system comprises a supporting unit, an energy storage unit, conversion units, a slow release unit and a control unit, an energy storage part of the energy storage unit has an energy storage position and an energy release position, each conversion unit comprises conversion mechanisms and a traction rope, the two conversion mechanisms are arranged on the two sides of the traction rope and are in transmission connection with the traction rope, and the traction rope is wound around the energy storage part. The slow release unit comprises a first pressing piece and a second pressing piece, and the traction rope is arranged between the first pressing piece and the second pressing piece in a penetrating mode. The control unit adjusts the first pressing piece to enable the first pressing piece to be close to or away from the second pressing piece so as to provide pressure for the traction rope, then the moving speed of the traction rope is adjusted, sudden rising and sudden falling of the energy storage piece are avoided, and then it is ensured that the gravity energy storage system has high stability and use safety.

Description

Technical Field

[0001] The present invention relates to the technical field of energy generation, and in particular to a gravity energy storage system and a control method. Background Art

[0002] Gravity energy storage is a way of storing and releasing energy through the conversion of gravitational potential energy and electrical energy. Specifically, it uses the height difference to cooperate with electromechanical equipment to achieve the lifting or lowering of the energy storage block to achieve energy storage and conversion. It is a highly sustainable innovative form of energy storage with the advantages of long discharge time, long cycle life, strong environmental adaptability and high safety. When there is surplus electricity generated by new energy, the surplus electricity is used to lift the energy storage block for "charging", and the gravitational potential energy is stored by raising the height of the heavy unit. When the power consumption is at its peak, the system lowers the energy storage block and uses gravity to do work to "discharge" and convert the gravitational potential energy into electrical energy for release.

[0003] Patent application number 202111551398.4 proposes a gravity energy storage system. The energy storage system creatively proposes to use multiple pulley groups to connect multiple weight units. There is no need to schedule the weight units, and all weight units can be discharged at the same time. This will be of great help in supporting the stability of the power grid frequency, greatly shortening the response time, and providing fast frequency response support. At the same time, the brake is used on the drum of the hoist to brake the hoist, thereby realizing the control of the gravity energy storage system. This control method cannot adjust the stress state of the wire rope, and the wire rope is directly connected to the hoist, which will cause coupling and cannot be controlled separately, which is easy to affect the stable operation of the system.

[0004] Therefore, a gravity energy storage system is needed to solve the above problems. Summary of the invention

[0005] The object of the present invention is to provide a gravity energy storage system and a control method, which can ensure that the gravity energy storage system has good stability by adjusting the pressure on the traction rope.

[0006] To achieve this object, the present invention adopts the following technical solutions:

[0007] A gravity energy storage system, the gravity energy storage system comprising:

[0008] Support unit;

[0009] An energy storage unit, the energy storage unit comprising an energy storage member, the energy storage member being disposed on the support unit and having an energy storage position and an energy release position;

[0010] A conversion unit, the conversion unit comprising a traction rope and two sets of conversion mechanisms, the two sets of conversion mechanisms are arranged on both sides of the traction rope and connected to the traction rope, the traction rope is wound around the energy storage component; the conversion unit can lift the energy storage component from the energy release position to the energy storage position and lock it under the drive of excess energy, so as to convert the excess energy into the gravitational potential energy of the energy storage component, and the conversion unit can unlock the energy storage component in the energy storage position, and the energy storage component descends from the energy storage position to the energy release position under the action of gravity, so as to convert the gravitational potential energy into target energy;

[0011] A pressure unit, the pressure unit is arranged between the conversion mechanism and the energy storage unit, the pressure unit comprises a first pressing member and a second pressing member, the traction rope is passed through the first pressing member and the second pressing member, and the first pressing member can be close to the second pressing member to apply pressure to the traction rope;

[0012] A control unit, wherein the control unit is electrically connected to the pressure-applying unit, and the control unit can adjust the pressure on the traction rope by adjusting the position of the first pressing member.

[0013] As an optional technical solution, the first pressing member is provided with a first groove, the second pressing member is provided with a second groove, the first groove and the second groove are arranged opposite to each other to form a channel, and the traction rope is passed through the channel.

[0014] As an optional technical solution, the pressure-applying unit further includes a driving member, which is transmission-connected to the first pressing member, and is used to drive the first pressing member to approach or move away from the second pressing member.

[0015] As an optional technical solution, the driving component is a hydraulic cylinder.

[0016] As an optional technical solution, the pressure unit also includes a fixed plate and a guide rod, the fixed plate is arranged on the side of the first clamping member away from the second clamping member, the driving member is installed on the fixed plate, the guide rod is connected between the fixed plate and the second clamping member, and the first clamping member is slidably arranged on the guide rod under the drive of the driving member.

[0017] As an optional technical solution, the pressure-applying unit further includes a pressure sensor, which is electrically connected to the control unit. The pressure sensor is disposed on the first clamping member and / or the second clamping member, and the control unit obtains the pressure exerted on the traction rope through the pressure sensor.

[0018] As an optional technical solution, the support unit includes a support structure and a fixed pulley, the fixed pulley is rotatably arranged on the top of the support structure, and the traction rope is wound around the fixed pulley.

[0019] As an optional technical solution, the gravity energy storage system also includes a guide unit, and the guide unit is arranged on at least one side of the pressure unit close to the energy storage unit, and the guide unit includes a guide wheel, and the traction rope is wound around the guide wheel; the height of the guide wheel is matched with the height of the conversion mechanism to make the traction rope between the guide wheel and the conversion mechanism horizontal, and the outer diameter of the guide wheel is matched with the outer diameter of the fixed pulley to make the traction rope between the guide wheel and the fixed pulley vertical.

[0020] As an optional technical solution, the guide unit further includes an encoder, which is electrically connected to the control unit. The encoder is used to collect the rotation speed of the guide wheel, and the control unit obtains the moving speed of the traction rope through the rotation speed.

[0021] The present invention adopts the following technical solutions:

[0022] A control method is applicable to the gravity energy storage system as described above, and the control method comprises:

[0023] S10, determining whether the gravity energy storage system is in the energy storage working process or the energy release working process, if it is in the energy storage working process, proceeding to S20, if it is in the energy release working process, proceeding to S30;

[0024] S20, the conversion unit causes the energy storage component to rise under the drive of excess energy, and the pressure applied by the pressure-applying unit to the traction rope is 0; after the energy storage component reaches a preset height, the pressure-applying unit applies pressure to the traction rope to slow down the rising speed of the energy storage component, until the energy storage component reaches the energy storage position, and the pressure-applying unit applies a preset pressure to the traction rope to completely brake the traction rope;

[0025] S30, the pressure-applying unit stops applying pressure to the traction rope, the energy storage component is unlocked, the energy storage component descends under the action of gravity, and drives the conversion mechanism to operate through the traction rope until the moving speed of the traction rope reaches a preset speed, the pressure-applying unit applies pressure to the traction rope so that the traction rope maintains the preset speed, until the energy storage component descends to the energy release position, the pressure-applying unit applies a preset pressure to the traction rope to completely brake the traction rope.

[0026] Beneficial effects of the present invention:

[0027] The invention discloses a gravity energy storage system, which comprises a supporting unit, an energy storage unit, a conversion unit, a slow-release unit and a control unit. The energy storage component of the energy storage unit has an energy storage position and an energy release position. The conversion unit comprises a conversion mechanism and a traction rope. Two sets of conversion mechanisms are arranged on both sides of the traction rope and are transmission-connected with the traction rope. The traction rope is wound around the energy storage component. The conversion unit can lift the energy storage component from the energy release position to the energy storage position and lock it under the drive of excess energy, so as to convert the excess energy into the gravitational potential energy of the energy storage component. The conversion unit can unlock the energy storage component in the energy storage position. The energy storage component descends from the energy storage position to the energy release position under the action of gravity, so as to convert the gravitational potential energy into target energy. The slow-release unit is arranged between the conversion mechanism and the energy storage unit. The slow-release unit comprises a first pressing component and a second pressing component. The traction rope is passed between the first pressing component and the second pressing component. The first pressing component can approach the second pressing component to apply pressure to the traction rope. The traction rope of this gravity energy storage system is passed between the first clamping member and the second clamping member. The control unit can make the first clamping member approach or move away from the second clamping member to provide appropriate pressure on the traction rope, thereby adjusting the moving speed of the traction rope, thereby improving the stability of the gravity energy storage system and avoiding sudden rise and fall of the energy storage member, thereby ensuring that the gravity energy storage system has high stability and safety in use.

[0028] The present invention also discloses a control method, which is applicable to the above-mentioned gravity energy storage system, and the control method includes S10, determining whether the gravity energy storage system is in the energy storage working process or in the energy release working process, if it is in the energy storage working process, then entering S20, if it is in the energy release working process, then entering S30; S20, the conversion unit causes the energy storage component to rise under the drive of excess energy, and the pressure unit does not apply pressure to the traction rope; after the energy storage component reaches a preset height, the pressure unit applies pressure to the traction rope to slow down the rising speed of the energy storage component until the energy storage component reaches After reaching the energy storage position, the pressure unit applies a preset pressure to the traction rope to completely brake the traction rope; S30, the pressure unit stops applying pressure to the traction rope, the energy storage component is unlocked, the energy storage component descends under the action of gravity, and the conversion mechanism is driven to operate through the traction rope until the moving speed of the traction rope reaches the preset speed, the pressure unit applies pressure to the traction rope so that the traction rope maintains the preset speed, until the energy storage component descends to the energy release position, the pressure unit applies a preset pressure to the traction rope to completely brake the traction rope. This control method can adjust the pressure unit based on the state of the gravity energy storage system, and then can adjust the size of all the pressures of the traction rope, and then adjust the lifting and lowering speed of the energy storage component, to ensure the stability of the gravity energy storage system, avoid energy loss, and improve conversion efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is a structural schematic diagram of a gravity energy storage system according to Embodiment 1 of the present invention;

[0030] Figure 2 is a schematic structural diagram of a pressure applying unit according to an embodiment of the present invention;

[0031] Figure 3 is a schematic diagram of a control unit according to an embodiment of the present invention;

[0032] Figure 4 is a schematic diagram of the power variation of the gravity energy storage system over time according to an embodiment of the present invention;

[0033] Figure 5 It is a structural schematic diagram of the gravity energy storage system of Example 2 of the present invention.

[0034] In the figure:

[0035] 10. Support unit; 11. Support structure; 12. Fixed pulley;

[0036] 20. Energy storage unit; 21. Energy storage component; 22. Movable pulley;

[0037] 30. conversion unit; 31. conversion mechanism; 32. traction rope;

[0038] 40. Pressure unit; 41. First pressing member; 411. First groove; 42. Second pressing member; 421. Second groove; 43. Channel; 44. Hydraulic cylinder; 45. Fixed plate; 46. Guide rod; 47. Fixed base; 48. Support plate; 49. Sliding plate; 410. Hydraulic pump;

[0039] 50. Control unit; 51. CPU module; 52. Power module; 53. Storage module; 54. Display module; 55. Digital input module; 56. Digital output module; 57. Analog input module; 58. Analog output module;

[0040] 60. Guide unit; 51. Guide wheel. DETAILED DESCRIPTION

[0041] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0042] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" 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 invention can be understood according to specific circumstances.

[0043] In the present invention, unless otherwise clearly 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.

[0044] In the description of this embodiment, the terms "upper", "lower", "right", etc., directions or positional relationships are based on the directions or positional relationships shown in the drawings, and are only for the convenience of description and simplification of operation, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used to distinguish in the description and have no special meaning.

[0045] Example 1

[0046] like Figures 1 to 4As shown, in this embodiment, a gravity energy storage system is provided, which includes a support unit 10, an energy storage unit 20, a conversion unit 30, a pressure unit 40 and a control unit 50. The energy storage unit 20 includes an energy storage member 21, which is arranged on the support unit 10, and the energy storage member 21 has an energy storage position and an energy release position. The conversion unit 30 includes a traction rope 32 and two sets of conversion mechanisms 31. The two sets of conversion mechanisms 31 are arranged on both sides of the traction rope 32 and connected to the traction rope 32. The traction rope 32 is wound around the energy storage member 21; the conversion unit 30 can lift the energy storage member 21 from the energy release position to the energy storage position and lock it under the drive of excess energy, so as to convert the excess energy into the energy storage member 21. 1, and the conversion unit 30 can unlock the energy storage member 21 in the energy storage position, and the energy storage member 21 drops from the energy storage position to the energy release position under the action of gravity to convert the gravitational potential energy into the target energy. The pressure unit 40 is arranged between the conversion mechanism 31 and the energy storage unit 20, and the pressure unit 40 includes a first clamping member 41 and a second clamping member 42. The traction rope 32 is passed through the first clamping member 41 and the second clamping member 42. The first clamping member 41 can be close to the second clamping member 42 to apply pressure to the traction rope 32; the control unit 50 is electrically connected to the pressure unit 40, and the control unit 50 can adjust the position of the first clamping member 41 to adjust the pressure on the traction rope 32.

[0047] Specifically, in this embodiment, the conversion unit 30 includes a traction rope 32 and two sets of conversion mechanisms 31. The two sets of conversion mechanisms 31 are arranged on both sides of the support unit 10 and are connected to both ends of the traction rope 32. The energy storage component 21 is supported on the support unit 10, and the traction rope 32 is wound around the energy storage component 21. The pressure unit 40 includes a first clamping component 41 and a second clamping component 42, and the pressure unit 40 is arranged between the conversion mechanism 31 and the energy storage unit 20. The first clamping component 41 can approach the second clamping component 42, thereby applying a certain pressure to the traction rope 32. In actual work, when it is necessary to store excess energy, the excess energy is used to lift the energy storage member 21 from the energy release position to the energy storage position and lock it through the conversion mechanism 31, thereby converting the excess energy into the gravitational potential energy of the energy storage member 21. During this period, the control unit 50 controls the first clamping member 41 to keep it and the second clamping member 42 away from each other, so as not to apply pressure to the traction rope 32, thereby avoiding energy loss during the energy conversion process. When the energy storage member 21 is lifted to the energy storage position, the first clamping member 41 is close to the second clamping member 42, and the control unit 50 controls the first clamping member 41 so that the pressure applied by the first clamping member 41 and the second clamping member 42 to the traction rope 32 reaches a preset value. value, achieving complete braking of the traction rope 32, and at the same time the conversion mechanism 31 stops working; when energy release is required, the conversion mechanism 31 can unlock the energy storage component 21 in the energy storage position, and under the action of gravity, the energy storage component 21 descends from the energy storage position to the energy release position, and at the same time the gravitational potential energy is converted into target energy. In the process of the energy storage component 21 descending from the energy storage position to the energy release position, the control unit 50 controls the first clamping component 41 so that the first clamping component 41 can approach the second clamping component 42, and then apply pressure to the traction rope 32, so that the moving speed of the traction rope 32 is reduced, the braking and deceleration of the traction rope 32 is achieved, and the stability of the gravity energy storage system can be ensured.

[0048] Specifically, in this embodiment, the control unit 50 includes a CPU module 51, a power module 52, a storage module 53, a display module 54, a digital input module 55, a digital output module 56, an analog input module 57 and an analog output module 58. The CPU module 51 is electrically connected to the power module 52, the storage module 53, the display module 54, the digital input module 55, the digital output module 56, the analog input module 57 and the analog output module 58. The digital input module 55 and the digital output module 56 are electrically connected to the conversion mechanism 31, and the analog input module 57 and the analog output module 58 are electrically connected to the pressure unit 40 and the guide unit 60. The CPU module 51 is the logic center of the control unit 50 and is used to process the control logic; the power module 52 provides energy for other modules of the control unit 50; the storage module 53 is used to store program codes, data and various status information during operation; the display module 54 is used to display system status, alarm information, operation prompts and other contents; the digital input module 55 is used to receive discrete signals from sensors or other devices, such as button press signals; the digital output module 56 is used to send control signals to the relays of the conversion mechanism 31 to control the start and stop of the generator and motor group. The analog input module 57 is used to receive data from the pressure sensor and the encoder, and feed it back to the CPU module 51; the analog output module 58 is connected to the servo valve of the pressure unit 40 to adjust the pressure in the hydraulic system. In actual work, the analog input module 57 receives the data from the encoder and obtains the moving speed of the traction rope 32 based on the data. If the moving speed of the traction rope 32 needs to be adjusted at this time, a signal is sent to the servo valve through the analog output module 58 to adjust the pressure setting value. The pressure sensor feeds back the actual pressure value to the analog input module 57, and then feeds it back to the CPU module 51. After comparing the deviation between the two, the control strategy is adjusted.

[0049] Specifically, in this embodiment, the traction rope 32 is a steel wire rope, which has good strength, thereby ensuring the service life of the gravity energy storage system, and the number of traction ropes 32 is 4, which can further ensure safety in use. In other embodiments, the number of traction ropes 32 can be specifically set according to actual use, which will not be repeated here.

[0050] Specifically, in this embodiment, the conversion mechanism 31 is a generator and a motor group, which includes an outer rotor synchronous generator with a large moment of inertia. The generator generates electrical energy when it is working, and stores it when there is excess electrical energy. When energy release is required, gravity energy release is converted into electrical energy again, which will not be described in detail here. In this embodiment, the conversion mechanism 31 also includes a relay, which is electrically connected to the generator and the motor group to control the start and stop of the generator and the motor group.

[0051] Further, the first pressing member 41 is provided with a first groove 411, and the second pressing member 42 is provided with a second groove 421. The first groove 411 and the second groove 421 are arranged opposite to each other to form a channel 43, and the traction rope 32 is passed through the channel 43. Specifically, in this embodiment, the first groove 411 provided on the first pressing member 41 and the second groove 421 provided on the second pressing member 42 form a channel 43, and the traction rope 32 is passed through the channel 43. The channel 43 is arranged corresponding to the number of the traction ropes 32, and there are also 4 channels 43. This arrangement can limit the traction rope 32, prevent the traction rope 32 from being displaced in the radial direction, and further ensure that the traction rope 32 can always be aligned with the conversion mechanism 31, thereby ensuring the stability of the gravity energy storage system.

[0052] In this embodiment, the maximum depths of the first groove 411 and the second groove 421 are both smaller than the radius of the traction rope 32, which can ensure that when the first clamping member 41 and the second clamping member 42 clamp the traction rope 32, there is still a gap between the first clamping member 41 and the second clamping member 42, thereby ensuring the effectiveness of clamping the traction rope 32.

[0053] Furthermore, the pressure unit 40 further includes a driving member, which is in transmission connection with the first pressing member 41, and is used to drive the first pressing member 41 to approach or move away from the second pressing member 42. Specifically, in this embodiment, the driving member is a hydraulic cylinder 44, and the telescopic rod of the hydraulic cylinder 44 is connected to the first pressing member 41. When the hydraulic cylinder 44 is telescopic, it drives the first pressing member 41 to move, thereby enabling the first pressing member 41 to approach or move away from the second pressing member 42, so as to apply pressure to the traction rope 32.

[0054] Furthermore, the pressure unit 40 also includes a fixed plate 45 and a guide rod 46. The fixed plate 45 is arranged on the side of the first clamping member 41 away from the second clamping member 42. The driving member is installed on the fixed plate 45. The guide rod 46 is connected between the fixed plate 45 and the second clamping member 42. The first clamping member 41 is slidably arranged on the guide rod 46 under the drive of the driving member. Specifically, in this embodiment, the pressure unit 40 includes a fixed base 47, a support plate 48 and a sliding plate 49, the driving member is a hydraulic cylinder 44, the second clamping member 42 is fixedly installed on the support plate 48, the first clamping member 41 is fixedly installed on the sliding plate 49, the support plate 48 is fixedly installed on the fixed base 47, the guide rod 46 is connected between the fixed plate 45 and the support plate 48, the sliding plate 49 is slidably set on the guide rod 46, the hydraulic cylinder 44 is installed on the fixed plate 45, the fixed base 47 can provide sufficient support for the support plate 48, the guide rod 46 can ensure that the support plate 48 and the fixed plate 45 have good parallelism, and at the same time, the sliding plate 49 is slidably set on the guide rod 46 driven by the hydraulic cylinder 44, and the guide rod 46 can have a guiding effect on the sliding plate 49, so that the first groove 411 of the first clamping member 41 and the second groove 421 of the second clamping member 42 can always be aligned, thereby ensuring the effectiveness of applying force to the traction rope 32.

[0055] Furthermore, the pressure unit 40 also includes a pressure sensor, which is electrically connected to the control unit 50. The pressure sensor is disposed on the first pressing member 41 and / or the second pressing member 42, and the control unit 50 obtains the pressure exerted on the traction rope 32 through the pressure sensor. Specifically, in this embodiment, a pressure sensor is disposed on the first pressing member 41 or the second pressing member 42, and the data monitored by the pressure sensor can be transmitted to the analog input module 57, which feeds it back to the CPU module 51, so that the pressure exerted on the traction rope 32 can be obtained in real time, and the working state of the traction rope 32 can be monitored according to the pressure value, thereby ensuring the safety of the gravity energy storage system.

[0056] Specifically, in this embodiment, the pressure unit 40 also includes a hydraulic pump 410, an oil supply device and a servo valve. The oil supply device, the hydraulic pump 410, the servo valve and the hydraulic cylinder 44 are connected in sequence through pipelines. The hydraulic pump 410 is a variable pump. The servo valve is electrically connected to the pressure sensor, and can change the flow rate output by the oil supply device according to actual needs, so that the hydraulic cylinder 44 can drive the first clamping member 41 to approach the second clamping member 42, and then provide smooth pressure to the traction rope 32, ensuring that the moving speed of the traction rope 32 meets the use requirements, thereby realizing stepless control of the pressure on the traction rope 32.

[0057] Further, the support unit 10 includes a support structure 11 and a fixed pulley 12, the fixed pulley 12 is rotatably arranged at the top of the support structure 11, and the traction rope 32 is wound around the fixed pulley 12. Specifically, in this embodiment, the fixed pulley 12 is rotatably arranged at the top of the support structure 11, the traction rope 32 is wound around the fixed pulley 12, and the support structure 11 is supported below the fixed pulley 12 to support the energy storage component 21. The setting of the fixed pulley 12 can reduce the friction resistance of the traction rope 32, reduce energy loss, and improve energy utilization. The main function of the support structure 11 is to bear weight, so it can be a steel structure or a concrete structure.

[0058] Specifically, in this embodiment, the energy storage unit 20 further includes a movable pulley 22, which is connected to the energy storage member 21, and the traction rope 32 is wound around the movable pulley 22. The movable pulley 22 reduces the friction resistance of the traction rope 32, reduces energy loss, and improves energy utilization.

[0059] Specifically, in this embodiment, four grooves are provided on the fixed pulley 12 and the movable pulley 22 for accommodating four traction ropes 32 in a one-to-one correspondence, thereby improving the stability of the gravity energy storage system.

[0060] Specifically, in this embodiment, in order to increase the total amount of energy storage of the entire gravity energy storage system, a plurality of energy storage components 21, movable pulleys 22 and fixed pulleys 12 can be provided. The movable pulley 22 is located between two adjacent fixed pulleys 12, and the traction rope 32 sequentially connects the movable pulleys 22 and the fixed pulleys 12 in series. The energy storage components 21, movable pulleys 22 and fixed pulleys 12 can be arranged in a multi-row and multi-column pattern to achieve a compact structure and reduce space occupation.

[0061] Furthermore, the gravity energy storage system also includes a guide unit 60, and at least the guide unit 60 is arranged on one side of the pressure unit 40 close to the energy storage unit 20, and the guide unit 60 includes a guide wheel 61, and the traction rope 32 is wound around the guide wheel 61; the height of the guide wheel 61 is matched with the height of the conversion mechanism 31 so that the traction rope 32 located between the guide wheel 61 and the conversion mechanism 31 is horizontal, and the outer diameter of the guide wheel 61 is matched with the outer diameter of the fixed pulley 12 so that the traction rope 32 located between the guide wheel 61 and the fixed pulley 12 is vertical. Specifically, in the present embodiment, the traction rope 32 is wound around the guide wheel 61, and the height of the guide wheel 61 is matched with the height of the conversion mechanism 31, so that the traction rope 32 between the guide wheel 61 and the conversion mechanism 31 is horizontal, which can ensure that the traction rope 32 passed through the channel 43 is horizontal, thereby ensuring that when the first clamping member 41 approaches the second clamping member 42 and applies pressure to the traction rope 32, the traction rope 32 will not be damaged due to pressure, and ensure that the pressure on the compressed part is balanced, thereby ensuring the service life of the entire gravity energy storage system; and the guide wheel 61 and the fixed pulley 12 are matched, which can make the traction rope 32 between the guide wheel 61 and the fixed pulley 12 vertical, and can make the pressure transmitted to the fixed pulley 12 by the traction rope 32 vertically downward, and will not generate the overturning force of the support unit 10 in the left and right direction, thereby improving the stability of the support unit 10, and thereby improving the stability of the gravity energy storage system.

[0062] Specifically, in this embodiment, the guide wheel 61 is provided with four wire grooves for accommodating four traction ropes 32 in a one-to-one correspondence, and a lining is provided on the inner wall of the wire groove to prevent the traction rope 32 from directly contacting the metal part of the guide wheel 61, thereby reducing the wear of the traction rope 32. The material of the lining can be polyurethane, nylon, ultra-high molecular polyethylene, rubber, rubber-plastic composite material, etc.

[0063] Furthermore, the guide unit 60 further includes an encoder, which is electrically connected to the control unit 50, and the encoder is used to collect the rotation speed of the guide wheel 61, and the control unit obtains the moving speed of the traction rope 32 through the rotation speed. Specifically, in this embodiment, due to the large weight of the energy storage member 21, there is friction between the guide wheel 61 and the traction rope 32, so that the guide wheel 61 and the traction rope 32 do not slide relative to each other, and the rotation speed of the guide wheel 61 can be obtained through the encoder, and transmitted to the analog input module 57, and the analog input module 57 feeds it back to the CPU module 51 to obtain the moving speed of the traction rope 32.

[0064] The present invention also provides a control method applicable to the above-mentioned gravity energy storage system, and the control method includes the following contents.

[0065] S10, determining whether the gravity energy storage system is in the energy storage working process or in the energy release working process, if it is in the energy storage working process, proceeding to S20; if it is in the energy release working process, proceeding to S30.

[0066] Specifically, in this embodiment, the working process needs to be determined according to actual conditions. If excess energy needs to be converted into the gravitational potential energy of the energy storage component 21, it is an energy storage working process. If the gravitational potential energy of the energy storage component 21 needs to be converted into target energy, it is an energy release working process.

[0067] S20, the conversion unit 30 causes the energy storage component 21 to rise under the drive of excess energy, and the pressure applied by the pressure unit 40 to the traction rope 32 is 0; after the energy storage component 21 reaches the preset height, the pressure unit 40 applies pressure to the traction rope 32 to slow down the rising speed of the energy storage component 21, until the energy storage component 21 reaches the energy storage position, the pressure unit 40 applies a preset pressure to the traction rope 32 to completely brake the traction rope 32.

[0068] Specifically, in the present embodiment, at the initial stage of the energy storage process, the energy storage component 21 rises driven by the excess energy, and the pressure unit 40 does not apply pressure to the traction rope 32 to avoid hindering the normal movement of the traction rope 32 and affecting the energy conversion efficiency. When the energy storage component 21 is lifted to a preset height, the pressure unit 40 starts to start and gradually applies pressure to generate pressure between the pressure unit 40 and the traction rope 32, thereby reducing the movement speed of the traction rope 32 to achieve braking and deceleration of the traction rope 32, which can avoid the energy storage component 21 from reaching the energy storage position at an excessive speed, thereby affecting the stability of the gravity energy storage system. After the energy storage component 21 reaches the energy storage position, the pressure unit 40 provides a preset pressure to the traction rope 32 to achieve complete braking of the traction rope 32, and at the same time the conversion unit 30 also stops working to complete the energy storage work.

[0069] S30, the pressure-applying unit 40 stops applying pressure to the traction rope 32, the energy storage component 21 is unlocked, and the energy storage component 21 descends under the action of gravity, driving the conversion mechanism 31 to operate through the traction rope 32 until the moving speed of the traction rope 32 reaches a preset speed. The pressure-applying unit 40 applies pressure to the traction rope 32 so that the traction rope 32 maintains a preset speed until the energy storage component 21 descends to the energy release position, and the pressure-applying unit 40 applies a preset pressure to the traction rope 32 to completely brake the traction rope 32.

[0070] Specifically, in this embodiment, before the gravity energy storage system is in the energy release process, the pressure unit 40 applies a preset pressure to the traction rope 32 to ensure the stability and safety of the gravity energy storage system. When releasing energy, the pressure unit 40 stops applying pressure to the traction rope 32, so that the energy storage member 21 descends under the action of gravity, and the traction rope 32 drives the generator and the generator in the motor group to idle. Because the idling torque of the generator is very small, after a very short acceleration time, the speed of the traction rope 32 can reach the synchronous speed of the generator, that is, the preset speed. After that, the control unit 50 operates to accelerate the generator. The generator is connected to the grid and supplies power to the external grid. At this time, the generator will generate a large electromagnetic torque, which hinders the movement of the generator outer rotor shell pulled by the traction rope 32. At this time, the control unit 50 adjusts the pressure applied to the traction rope 32 by adjusting the pressure unit 40 based on the obtained moving speed and pressure of the traction rope 32, and then adjusts the speed of the traction rope 32 to always maintain a preset speed, thereby achieving stable operation of the generator at a constant speed. When the electromagnetic torque of the generator is reduced, the control unit 50 can also adjust the pressure applied to the traction rope 32 by the pressure unit 40, thereby preventing the generator speed from rising rapidly.

[0071] The discharge response time is estimated as follows:

[0072] Assume that the gravity energy storage system is composed of N energy storage components 21 with a mass of m, the gravity of each energy storage component 21 is mg, each energy storage component 21 is connected to a movable pulley 22, and each is connected to the movable pulley 22 by two sections of steel wire rope. If the weight of the movable pulley 22 is ignored, the tension of the rope is mg / 2.

[0073] The energy that can be released (or stored) by the gravity energy storage system due to the height difference is:

[0074] Eg J =NmgΔh

[0075] Calculated in kWh:

[0076] Eg kWh =Eg J / 3600000

[0077] Among them, Eg J : Energy stored in the gravity energy storage system, unit J; Eg kWh : The energy stored in the weight energy storage system, in kWh; N: The number of energy storage components 21, that is, the number of movable pulleys 22; g: Gravitational acceleration, 10, in m / s 2 ; m: weight of a single energy storage component 21 of the gravity energy storage system, unit: kg; Δh: height difference between the energy storage position and the energy release position of the energy storage component 21, unit: m.

[0078] Ideally, ignoring friction and generator no-load torque, the speed of the energy storage member 21 in free fall at time t is:

[0079] v 物 =gt

[0080] Since there is a drum on each side of the wire rope to wrap the wire rope, the speed of the rope is:

[0081] v 绳 =Ngt

[0082] Ideally the motor power is:

[0083] P M =F 拉 v 绳 =mg / 2*Ngt=mNg 2 t / 2

[0084] In the formula, v 物 : The speed of the energy storage element 21, in m / s; v 绳 : The speed of the wire rope, in m / s; N: The number of energy storage components 21, that is, the number of movable pulleys 22; g: The acceleration due to gravity, which is 10, in m / s 2 ; t: time for the weight to fall, unit s; m: weight of a single energy storage component 21 of the gravity energy storage system, unit kg; PM: power of the generator, W; F 拉 : Tension of wire rope, unit N.

[0085] Assuming that the mass of the energy storage component 21 is 5000 kg, g is 10, and N is 100, a power of 1000 kW can be achieved in 0.04 s, and the response speed can reach the second level, which can theoretically prove the effect that the device of the present invention can achieve.

[0086] Example 2

[0087] This embodiment provides a gravity energy storage system. The only difference between this gravity energy storage system and the gravity energy storage system in Embodiment 1 is that guide units 60 are provided on both sides of the pressure unit 40 .

[0088] Specifically, in the present embodiment, guide units 60 are provided on both sides of the pressure unit 40. The two guide units 60 can further ensure that the traction rope 32 passing through the channel 43 is in a horizontal state, and can ensure that when the first clamping member 41 approaches the second clamping member 42 and applies pressure to the traction rope 32, the traction rope 32 will not be damaged due to pressure, and ensure that the pressure on the compressed part is balanced, thereby ensuring the service life of the entire gravity energy storage system.

[0089] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, various obvious changes, readjustments and substitutions can be made without departing from the protection scope of the present invention. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. Gravity energy storage system, characterized in that: The gravity energy storage system comprises: Support unit (10); An energy storage unit (20), the energy storage unit (20) comprising an energy storage member (21), the energy storage member (21) being arranged on the support unit (10), and the energy storage member (21) having an energy storage position and an energy release position; A conversion unit (30), the conversion unit (30) comprising a traction rope (32) and two sets of conversion mechanisms (31), the two sets of conversion mechanisms (31) being arranged on both sides of the traction rope (32) and connected to the traction rope (32), the traction rope (32) being wound around the energy storage component (21); the conversion unit (30) can, driven by excess energy, lift the energy storage component (21) from the energy release position to the energy storage position and lock it, so as to convert the excess energy into the gravitational potential energy of the energy storage component (21), and the conversion unit (30) can unlock the energy storage component (21) in the energy storage position, so that the energy storage component (21) descends from the energy storage position to the energy release position under the action of gravity, so as to convert the gravitational potential energy into target energy; A pressure-applying unit (40), the pressure-applying unit (40) being arranged between the conversion mechanism (31) and the energy storage unit (20), the pressure-applying unit (40) comprising a first pressing member (41) and a second pressing member (42), the traction rope (32) being passed through the first pressing member (41) and the second pressing member (42), the first pressing member (41) being able to approach the second pressing member (42) to apply pressure to the traction rope (32); A control unit (50), wherein the control unit (50) is electrically connected to the pressure-applying unit (40), and the control unit (50) can adjust the pressure applied to the traction rope (32) by adjusting the position of the first pressing member (41).

2. The gravity energy storage system according to claim 1, characterized in that: The first pressing member (41) is provided with a first groove (411), the second pressing member (42) is provided with a second groove (421), the first groove (411) and the second groove (421) are arranged opposite to each other to form a channel (43), and the traction rope (32) is passed through the channel (43).

3. The gravity energy storage system according to claim 1, characterized in that: The pressure-applying unit (40) further comprises a driving member, the driving member being in transmission connection with the first pressing member (41), the driving member being used to drive the first pressing member (41) to approach or move away from the second pressing member (42).

4. The gravity energy storage system according to claim 3, characterized in that: The driving member is a hydraulic cylinder (44).

5. The gravity energy storage system according to claim 3, characterized in that: The pressure unit (40) further comprises a fixing plate (45) and a guide rod (46), wherein the fixing plate (45) is arranged on a side of the first pressing member (41) away from the second pressing member (42), the driving member is mounted on the fixing plate (45), the guide rod (46) is connected between the fixing plate (45) and the second pressing member (42), and the first pressing member (41) is slidably arranged on the guide rod (46) under the drive of the driving member.

6. The gravity energy storage system according to claim 1, characterized in that: The pressure-applying unit (40) further comprises a pressure sensor, the pressure sensor being electrically connected to the control unit (50), the pressure sensor being arranged on the first pressing member (41) and / or the second pressing member (42), and the control unit (50) obtaining the pressure exerted on the traction rope (32) through the pressure sensor.

7. The gravity energy storage system according to any one of claims 1 to 6, characterized in that: The support unit (10) comprises a support structure (11) and a fixed pulley (12); the fixed pulley (12) is rotatably arranged on the top of the support structure (11), and the traction rope (32) is wound around the fixed pulley (12).

8. The gravity energy storage system according to claim 7, characterized in that: The gravity energy storage system further comprises a guide unit (60), wherein at least one side of the pressure applying unit (40) close to the energy storage unit (20) is provided with the guide unit (60), and the guide unit (60) comprises a guide wheel (51), and the traction rope (32) is wound around the guide wheel (51); the height of the guide wheel (51) is matched with the height of the conversion mechanism (31) so that the traction rope (32) between the guide wheel (51) and the conversion mechanism (31) is horizontal, and the outer diameter of the guide wheel (51) is matched with the outer diameter of the fixed pulley (12) so that the traction rope (32) between the guide wheel (51) and the fixed pulley (12) is vertical.

9. The gravity energy storage system according to claim 8, characterized in that: The guide unit (60) further comprises an encoder, which is electrically connected to the control unit (50), and is used to collect the rotation speed of the guide wheel (51). The control unit (50) obtains the moving speed of the traction rope (32) through the rotation speed.

10. A control method, applicable to the gravity energy storage system according to claim 9, characterized in that: The control method comprises: S10, determining whether the gravity energy storage system is in the energy storage working process or the energy release working process, if it is in the energy storage working process, proceeding to S20, if it is in the energy release working process, proceeding to S30; S20, the conversion unit (30) causes the energy storage component (21) to rise under the drive of excess energy, and the pressure applied by the pressure-applying unit (40) to the traction rope (32) is 0; after the energy storage component (21) reaches a preset height, the pressure-applying unit (40) applies pressure to the traction rope (32) to slow down the rising speed of the energy storage component (21), until the energy storage component (21) reaches the energy storage position, and the pressure-applying unit (40) applies a preset pressure to the traction rope (32) to completely brake the traction rope (32); S30, the pressure-applying unit (40) stops applying pressure to the traction rope (32), the energy storage component (21) is unlocked, the energy storage component (21) descends under the action of gravity, and drives the conversion mechanism (31) to operate through the traction rope (32) until the moving speed of the traction rope (32) reaches a preset speed, the pressure-applying unit (40) applies pressure to the traction rope (32) so that the traction rope (32) maintains the preset speed, until the energy storage component (21) descends to the energy release position, and the pressure-applying unit (40) applies a preset pressure to the traction rope (32) to completely brake the traction rope (32).

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