CN114928112A

CN114928112A - Multilayer gravity energy storage system and energy storage method

Info

Publication number: CN114928112A
Application number: CN202210491909.6A
Authority: CN
Inventors: 孙香宇; 钟晓晖; 宋娟娟; 荣晓敏
Original assignee: Institute of Engineering Thermophysics of CAS
Current assignee: Institute of Engineering Thermophysics of CAS
Priority date: 2022-05-07
Filing date: 2022-05-07
Publication date: 2022-08-19

Abstract

The application provides a multilayer gravity energy storage system and an energy storage method, wherein the system comprises a plurality of layers of storage yards for storing heavy blocks, and each layer of storage yard is provided with a stacking unit and a transferring unit; the lifting device further comprises a lifting unit, a descending unit and a control unit, and the control unit is connected with other units and controls the other units. The method comprises the steps of inputting load data, calculating a power difference value, and judging energy storage and release requirements; calculating the product Mh of the mass and the height of the heavy object blocks to be transported; during energy storage or energy release, according to the Mh, the number of the heavy blocks to be transported and the required running distance of each heavy block in each lifting unit or each descending unit are calculated by taking the path optimization as a target; and transferring the stacking unit and the transferring unit according to the calculation result, and transferring the required heavy object blocks to enter a designated layer storage yard. Through the processing scheme of this application, application scope is wide, convenient to use, and energy storage and energy release furthest match with the required energy of electric wire netting in real time.

Description

Multilayer gravity energy storage system and energy storage method

Technical Field

The application relates to the technical field of power generation and energy storage, in particular to a multilayer gravity energy storage system and an energy storage method.

Background

At present, the loading amount of fluctuating energy mainly comprising wind energy and solar energy is rapidly increased, the wind energy and the solar energy are greatly influenced by natural factors, the outstanding problems are randomness and intermittence of power generation, a plurality of problems are brought in the aspects of power balance, electric quantity consumption, stable control and the like after the wind energy and the solar energy are connected into a power grid in a large scale, the power fluctuation is large, if power is forcibly adjusted, a large amount of wind abandoning and light abandoning are realized, and high requirements and new challenges are brought to rapid and flexible adjustment of a power system.

The existing power system energy storage technology comprises water pumping energy storage, compressed air energy storage, storage battery energy storage, flywheel energy storage, electric hydrogen production energy storage, superconducting energy storage, super capacitor energy storage and the like. In the aspect of physical energy storage, a water pumping energy storage technology is developed most widely, the energy storage scale and power are large, but the water pumping energy storage needs special geographical conditions, the construction period is long, the initial investment is large, and in addition, the utilization efficiency is only about 75% generally due to the evaporability of medium water. Based on this, in recent years, gravity energy storage has been developed as another important energy storage means in physical energy storage. The gravity energy storage modes which have been researched at present mainly include piston type gravity energy storage, suspension type gravity energy storage, concrete block energy storage towers and mountain gravity energy storage, buoyancy energy storage similar to the gravity energy storage principle and the like. The basic principle of gravity energy storage power generation is similar to the pumped storage technology, and the basic processes of energy storage and power generation are as follows: lifting heavy objects by utilizing surplus electric power and storing potential energy; when needed, the potential energy of the heavy object is released, and the generator is driven to generate electricity through conversion.

In the prior gravity energy storage device, a lifting device is basically fixed at a horizontal height, the distance between an upper bin and a lower bin is fixed, and the general specifications of weights are the same, so that the product of the mass and the height of a weight block which ascends and descends an energy storage system is jump-stepped, the energy used by a user side and the energy stored and released by the system are difficult to match in real time, and certain obstruction is met in the aspect of capacity expansion.

Disclosure of Invention

In view of this, embodiments of the present disclosure provide a multi-layer gravity energy storage system and an energy storage method, and an object of the present disclosure is to provide an algorithm that can maximally match a product of mass and height of a lifted or lowered weight with energy storage and release energy to maximally utilize energy, and simultaneously assist in minimizing a moving distance between layers of a weight, so that the weight can be flexibly called on the basis of satisfying a coupling property of transforming a waste floor into a gravity energy storage device.

In a first aspect, an embodiment of the present application provides a multilayer gravity energy storage system, where the system includes multiple layers of storage yards for storing heavy objects, each layer of the storage yard is provided with a stacking unit and a transferring unit, the stacking unit is used for picking and placing the heavy objects, and the transferring unit is used for transporting the heavy objects;

the system further comprises a lifting unit and a descending unit, wherein the lifting unit is used for lifting the heavy blocks transported by the transferring unit to a storage yard of a specified layer for energy storage, and the descending unit is used for descending the heavy blocks transported by the transferring unit to the storage yard of the specified layer for energy release;

the system also comprises a control unit which is connected with each unit in the system and controls the units.

According to a concrete implementation mode of the embodiment of the application, the transfer unit comprises a transverse track and a transfer trolley, and the transfer trolley moves and transports the heavy object blocks on the transverse track.

According to a specific implementation manner of the embodiment of the application, the stacking unit comprises a moving track and a manipulator, the manipulator is located on the moving track to slide, and the manipulator is used for grabbing and placing the heavy object blocks.

According to a specific implementation manner of the embodiment of the application, each of the lifting unit and the descending unit comprises a power generation and electric integration machine, a transmission assembly and a transportation rail, and the transmission assembly is connected with the heavy object; in the lifting unit, the transmission assembly lifts the heavy object blocks along the transportation track under the action of the power generation and electric integrated machine; in the descending unit, the transmission assembly descends along the transportation rail under the action of the power generation and electric integrated machine.

In a second aspect, an embodiment of the present application further provides an energy storage method of a multilayer gravity energy storage system, where the multilayer gravity energy storage system according to any embodiment of the first aspect is adopted, where the energy storage method includes:

the control unit inputs load data, calculates a power difference value and judges the energy storage and release requirements;

calculating the product Mh of the mass and the height of the heavy object blocks to be transported according to the power difference;

when energy storage is needed, the lifting unit is moved to store energy, and when energy release is needed, the descending unit is moved;

during energy storage or energy release, according to the Mh, the number of heavy blocks to be transported and the required running distance of each heavy block in each lifting unit or each descending unit are calculated by taking the path optimization as a target;

and the control unit moves the stacking unit and the transferring unit according to the number of the heavy blocks and the required running distance of each heavy block in each lifting unit or each descending unit, and moves the required heavy blocks to enter a storage yard of a specified layer.

According to a specific implementation manner of the embodiment of the present application, the load data includes wind energy Pw, solar energy Pv, and power P required by a user side, and a power difference is Δ P, then Δ P ═ Pw + Pv-P |;

when the energy storage and release requirements are judged, if Pw + Pv > P, the energy storage requirements are met; if Pw + Pv is less than or equal to P, the energy releasing requirement is met.

According to a specific implementation manner of the embodiment of the present application, when the yard is m layers, the number j of the heavy object blocks is equal to m, and the number i of the lifting units/the lowering units is equal to m (m-1)/2.

According to a specific implementation manner of the embodiment of the application, the calculating the number of the heavy blocks required to be transported includes calculating the types of the heavy blocks required to be transported and the corresponding number of the heavy blocks under each type.

According to a specific implementation manner of the embodiment of the application, in the step of calculating the number of weight blocks to be transported and the required travel distance of each weight block in each lifting unit or each descending unit with the goal of finding the optimal path, the constraint conditions include: the total length of travel of each kind of weight is an integral multiple of the sum of the travel distance of each kind of weight on each lifting unit/descending unit, the sum of the products of each kind of weight and the travel distance is equal to the Mh, and the sufficient supply transfer amount of each kind of weight in each layer yard is provided.

Advantageous effects

According to the multilayer gravity energy storage system and the energy storage method in the embodiment of the application, the upper bin and the lower bin of the traditional gravity energy storage are changed into the multilayer, so that the modular design is realized, the assembly is convenient, and the capacity expansion convenience of the gravity energy storage can be realized; (2) according to the invention, a single-specification weight for storing energy by gravity is changed into a multi-specification weight, so that the energy storage and release can be matched with energy required by a power grid to the maximum extent in real time; (3) the invention introduces an optimization algorithm to optimize and configure the types and the number of the heavy blocks to be carried at each layer and the distance to be traveled.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

FIG. 1 is a schematic structural diagram of a multi-layer gravity energy storage system according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of a transfer unit of a multi-layer gravity energy storage system according to an embodiment of the invention;

FIG. 3 is a schematic diagram of a stacking unit of a multi-layer gravity energy storage system according to an embodiment of the invention;

FIG. 4 is a schematic diagram of a lifting unit of a multi-layer gravity energy storage system according to an embodiment of the invention;

fig. 5 is a flowchart of an energy storage method of a multi-layer gravity energy storage system according to an embodiment of the invention.

In the figure: 1. a transfer unit; 2. a transverse rail; 3. a stacking unit; 4. a lowering unit; 5. a lifting unit; 6. a layer of yard; 7. a second layer of yard; 8. three layers of storage yards; 9. four-layer storage yard; 10. five layers of storage yards; 11. an ascending transportation track; 12. a descending transportation track; 13. a control unit; 14. an external renewable energy power generation unit; 15. a drive chain; 16. a power generation and electric integrated machine; 17. a heavy material block; 18. a transfer trolley; 19. a manipulator; 20. and moving the track.

Detailed Description

Embodiments of the present application are described in detail below with reference to the accompanying drawings.

The following embodiments of the present application are described by specific examples, and other advantages and effects of the present application will be readily apparent to those skilled in the art from the disclosure of the present application. It is to be understood that the embodiments described are only a few embodiments of the present application and not all embodiments. The present application is capable of other and different embodiments and its several details are capable of modifications and/or changes in various respects, all without departing from the spirit of the present application. It should be noted that the features in the following embodiments and examples may be combined with each other without conflict. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

It is noted that various aspects of the embodiments are described below within the scope of the appended claims. It should be apparent that the aspects described herein may be embodied in a wide variety of forms and that any specific structure and/or function described herein is merely illustrative. Based on the present application, one skilled in the art should appreciate that one aspect described herein may be implemented independently of any other aspects and that two or more of these aspects may be combined in various ways. For example, an apparatus may be implemented and/or a method practiced using any number of the aspects set forth herein. Additionally, such an apparatus may be implemented and/or such a method may be practiced using other structure and/or functionality in addition to one or more of the aspects set forth herein.

It should be further noted that the drawings provided in the following embodiments are only schematic illustrations of the basic concepts of the present application, and the drawings only show the components related to the present application rather than the numbers, shapes and dimensions of the components in actual implementation, and the types, the numbers and the proportions of the components in actual implementation may be arbitrarily changed, and the layout of the components may be more complicated.

In addition, in the following description, specific details are provided to facilitate a thorough understanding of the examples. However, it will be understood by those skilled in the art that the aspects may be practiced without these specific details.

According to the first aspect, the embodiment of the application provides a multilayer gravity energy storage system, the system adopts a modular design, changes an upper bin and a lower bin of the traditional gravity energy storage into a multilayer, can be applied to abandoned buildings, abandoned wells or desert areas, and is flexible in site selection and convenient to use. The multi-layer gravity energy storage system is described in detail below with reference to fig. 1-4.

Referring to fig. 1, the multi-level gravity energy storage system includes a plurality of storage yards for storing the heavy objects 17, and in this embodiment, a five-level storage yard is taken as an example, and includes a first-level storage yard 6, a second-level storage yard 7, a third-level storage yard 8, a fourth-level storage yard 9 and a fifth-level storage yard 10. A stacking unit 3 and a transfer unit 1 are arranged in each layer of storage yard, the stacking unit 3 is used for grabbing and placing the weight blocks 17, the transfer unit 1 is used for transporting the weight blocks 17, for example, when the weight blocks 17 need to be loaded into the transfer unit 1, the weight blocks 17 can be grabbed and placed in the transfer unit 1 through the stacking unit 3, or when the weight blocks 17 in the transfer unit 1 need to be unloaded, the weight blocks 17 in the transfer unit 1 can be grabbed and placed in the storage yard through the stacking unit 3, namely, the weight blocks 17 between the same layer of storage yard are transported through the transfer unit 1 and the stacking unit 3.

The multilayer gravity energy storage system further comprises a lifting unit 5 and a descending unit 4, wherein the lifting unit 5 is used for lifting the heavy blocks 17 transported by the transporting unit 1 to a storage yard of a specified layer for energy storage, and the descending unit 4 is used for descending the heavy blocks 17 transported by the transporting unit to the storage yard of the specified layer for energy release.

In one embodiment, two five-level groups of yards are provided, and referring to fig. 1, one group of lifting units 5 and one group of lowering units 4 are provided on each side of each group of yards, i.e. there are two groups of lifting units 5 and two groups of lowering units 4.

The multilayer gravity energy storage system further comprises a control unit 13, and the control unit 13 is connected with and controls each unit in the system. In addition, the control unit 13 is further connected to an external renewable energy power generation unit 14, such as an external photovoltaic power generation system or a wind power generation system, the control unit 13 may receive power input by the external renewable energy power generation unit 14, and determine whether the multilayer gravity energy storage system needs to release energy or store energy according to power required by a user side, and the control unit 13 controls each unit in the system to operate according to the determination result to release energy or store energy.

In order to make the transfer unit 1 more convenient for transporting the heavy objects 17, the transfer unit 1 comprises a transverse rail 2 and a transfer trolley 18, with reference to fig. 2, said transfer trolley 18 moving on said transverse rail 2 completing the transportation of said heavy objects 17 in the same yard.

In one embodiment, the palletizing unit 3 comprises a moving track 20 and a robot 19, with reference to fig. 3, the robot 19 slides on the moving track 20, and the robot 19 is used for grasping and placing the heavy objects 17.

In another embodiment, the lifting unit 5 and the lowering unit 4 each comprise a generator-motor unity machine 16, a transmission assembly and a transport track, the transmission assembly being connected with the weight block 17, see fig. 4. For the lifting unit 5, the transportation rail is set as an ascending transportation rail 11, for the descending unit 4, the transportation rail is set as a descending transportation rail 12, and the ascending transportation rail 11 and the descending transportation rail 12 are matched with the transverse rail 2 in the transfer unit 1 to bear the heavy object 17 transported by the transfer trolley 18. In the lifting unit 5, the transmission assembly lifts the heavy object block 17 along an ascending transportation rail 11 under the action of the power generation and electric integration machine 16; in the descending unit 4, the transmission assembly descends the heavy object block 17 along the descending transportation track 12 under the action of the power generation and electric integration machine 16. In the actual use process, the transmission assembly can be set as a transmission chain 15 or a pulley block, in this embodiment, the transmission assembly is set as the transmission chain 15, the movable end of the transmission chain 15 is connected with the heavy object 17, and the transmission assembly 15 can be adjusted according to the actual situation.

In order to facilitate transportation, a lifting unit 5 and a lowering unit 4 may be provided in each of the multi-story yards, respectively, as shown in fig. 1.

In a second aspect, an embodiment of the present application further provides an energy storage method for a multilayer gravity energy storage system, where the multilayer gravity energy storage system described in any embodiment of the first aspect is adopted, and a flow of the energy storage method refers to fig. 5, and specifically includes the following steps:

step 1, a control unit inputs load data, calculates a power difference value and judges the energy storage and release requirements.

Specifically, the load data includes wind energy Pw, solar energy Pv and power P required by the user side, and the power difference is Δ P, where the wind energy is power input by the wind power generation system, the solar energy is power input by the photovoltaic power generation system, the wind energy Pw and the solar energy Pv are used as the supply side, the power P required by the user side is generally required power of the grid side, and then the calculation formula of Δ P is: Δ P ═ Pw + Pv-P |; when the energy storage and release requirements are judged, if Pw + Pv > P, the energy storage requirements are met; if Pw + Pv is less than or equal to P, the energy releasing requirement is met.

And 2, calculating the product Mh of the mass and the height of the heavy object block 17 to be transported according to the power difference.

In this step, the calculation formula is:

in the formula, μ 1 is transmissionThe transmission efficiency of the movable component, mu 2 is the efficiency of the power generation and electric integrated machine 16, g is the gravity acceleration, and the product Mh of the mass and the height of the heavy object blocks 17 to be transported can be calculated through the calculation formula in the step.

And 3, according to the judgment result in the step 1, the lifting unit 5 is moved to store energy when energy storage is needed, and the descending unit 4 is moved when energy release is needed.

And 4, when energy storage or energy release is carried out, aiming at finding path optimization according to the Mh, and calculating the quantity of the heavy blocks to be transported and the required running distance of each heavy block in each lifting unit or each descending unit. And calculating the quantity of the heavy blocks to be transported, wherein the quantity of the heavy blocks to be transported comprises calculating the types of the heavy blocks to be transported and the corresponding quantity of the heavy blocks under each type.

When the storage yard is m layers, the number j of the heavy object blocks is m, and the number i of the lifting units/the descending units is m (m-1)/2.

In the present embodiment, a gravity energy storage system of five-layer yard is used for description, i.e. m ═ 5, with reference to fig. 1, two sets of lifting units 5 are provided at both sides of the yard, two sets of lowering units 4 are provided in the middle of the yard, the lifting unit 5 at each side includes one from the second layer to the first layer, the third layer respectively reaches two from the first layer and the second layer, the fourth layer respectively reaches three from the first layer, the second layer and the third layer, the fifth layer respectively reaches four from the first layer, the second layer, the third layer and the fourth layer, and there are ten devices in total, i ═ 10.

Taking energy storage as an example, in order to enable the system to more properly and orderly transport the heavy blocks 17 and simultaneously match the work amount of the heavy blocks 17 with the energy storage demand amount as much as possible in real time, a control algorithm is introduced in the embodiment to find the optimal path as a target, so as to obtain the types (numbered by j, five types in total) of the heavy blocks 17 to be transported by each lifting unit 5 and the corresponding number n of each type _ij And also the total distance L that such a weight-like mass 17 needs to be lifted _j 。

The control algorithm in the embodiment adopts a particle swarm algorithm, and mainly comprises the following steps:

step 41Setting particle velocity, initial position value { n } _j H and _ij }，n _j the number, h, to be moved for each weight mass 17 _ij The distance of movement of the weight blocks 17 of different kinds for each lifting unit 5;

step 42, checking the particle feasibility, namely setting constraint conditions;

step 43, calculating a particle fitness value;

step 44, comparing the particle fitness value and the current optimal value of the particles with the global optimal value, and updating the current optimal value and the global optimal value;

step 45, updating the weight, and updating the speed and the position of the particle swarm;

and step 46, judging whether the iteration times are reached or the error is smaller than the specified error, if not, restarting the step 41, and if so, ending the algorithm for searching the optimal path.

The above constraint conditions mainly include: the total length traveled by each category of weight 17 should be an integer multiple of the sum of the travel of each category of weight on each device, i.e.:

in the formula, h _ij For each lifting unit 5, the moving distance of the different kinds of weight blocks 17 is 1 to 5, j is 1 to 5, i is 1 to 10, as shown in the formulas (2) to (6) on the right side of fig. 5, and the specific formulas (2) to (6) are:

the constraint condition also includes that the sum of the products of each kind of weight block and the distance traveled is equal to the value Mh calculated in step 2, and the calculation formula is as follows:

in the formula, n _j Number of pieces, m, to be moved for each kind of weight 17 _j The mass of each mass 17 is shown in equation (7) in fig. 5.

The constraints also include that each layer of weight 17 of each kind has sufficient supply capacity, as shown in equation (8) in fig. 5, that is:

n _j(1-5) ≤N _j(1-5) ,

in the formula, n _j(1-5) For calculating the number of weights 17 to be moved per layer yard, N _j(1-5) The number of heavy objects 17 present for each layer yard.

Step 5, the control unit is used for controlling the weight block number n according to the weight block number _j And the distance h that each weight block needs to travel in each lifting unit 5 or lowering unit 4 _ij And the stacking unit 3 and the transferring unit 1 are moved to cooperate with the lifting unit 5 or the descending unit 4 to move the required heavy object blocks 17 to enter a storage yard of a specified layer.

For energy storage operation, the calculated number n of weight blocks _j And the distance h each weight piece needs to travel at each lifting unit 5 _ij The materials are conveyed out of the stacking device 3, the transfer device 1 and the lifting device 5, and the algorithm is provided in a second storage yard 7, a third storage yard 8, a fourth storage yard 9 and a fifth storage yard 10The number of the heavy blocks 17 of different specifications needing to move is determined, the control system 13 sends signals to the transfer units 1 and the stacking devices 3 of each layer through the data, each unit starts to find the heavy blocks 17 which are in accordance with the stack yard of the layer and transports the heavy blocks to the transverse rails 2, the transverse rails 2 are provided with transfer trolleys 18 which move back and forth to complete the transportation, the heavy blocks 17 are transported to the ends of the transverse rails 2 and then enter the ascending transportation rails 11 of the lifting units 5 to be lifted, the heavy blocks 17 of each layer are transported by the two groups of lifting units 5 to enter the appointed layer according to the result of the optimization algorithm, the heavy blocks 17 enter the transfer units 1 after reaching the appointed layer, and the transfer units 1 distribute the heavy blocks into the module stacks of corresponding specifications and are placed by the stacking units 3. At this time, the lifting units 5 on each layer are driven by the power generation and electric integration machine 16 through the transmission chain 15, and at this time, the power generation and electric integration machine 16 has a motor function, and heavy objects are lifted by utilizing surplus electric power to store potential energy.

In the energy releasing state, the working process is opposite to the energy storing process, only the process passes through the descending unit 4, the lifting units 5 on the two sides are closed to operate, the power generation and motor integrated machine 16 is represented as a generator, and the power generation and motor integrated machine works repeatedly.

It should be noted that, in the foregoing method, five storage yards are taken as an example, in an actual gravity energy storage system, the number of layers of the storage yard and the number of each unit may be set according to a use situation and an environment, which is not limited to the examples listed in the foregoing embodiment, and the corresponding energy storage method is adjusted to achieve maximum energy utilization.

The large-scale efficient gravity energy storage system disclosed by the invention has the advantages of simple structure, convenience in assembly, small occupied area, low construction cost, long service life, high conversion efficiency, good reliability and high safety coefficient, can assist a power grid to realize smooth output, eliminate day and night peak-valley difference, peak-regulation frequency-modulation and reserve capacity, meet the requirements of stable power generation of new energy and safe access to the power grid, and can effectively reduce the phenomena of wind abandonment, light abandonment and the like.

The novel waste floor gravity energy storage system provided by the invention has the advantages of simple structure, realization of modular design, convenience in assembly and flexible site selection, can be used in waste buildings, and can also be used in waste wells, deserts and other areas; the cost is low, the maintenance is convenient, the energy conversion efficiency is high, and the reliability and the stability are good; the wind power generation device can be matched with a photovoltaic power generation or wind power generation system, renewable energy sources are fully utilized, the phenomena of wind abandonment and light abandonment are reduced, and meanwhile, the wind power generation device can also assist in energy structure upgrading and help in power grid peak regulation and frequency modulation.

Although the invention herein has been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the present invention. It is therefore to be understood that numerous modifications may be made to the illustrative embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims. It should be understood that features described in different dependent claims and herein may be combined in ways different from those described in the original claims. It is also to be understood that features described in connection with individual embodiments may be used in other described embodiments.

Claims

1. The multilayer gravity energy storage system is characterized by comprising a plurality of layers of storage yards for storing heavy objects, wherein each layer of the storage yard is provided with a stacking unit and a transferring unit, the stacking unit is used for grabbing and placing the heavy objects, and the transferring unit is used for transporting the heavy objects;

2. The multi-level gravity energy storage system according to claim 1, wherein the transfer unit comprises a transverse rail and a transfer trolley that moves on the transverse rail to transport the heavy mass.

3. The multi-level gravity energy storage system according to claim 1, wherein the stacking unit comprises a moving track and a robot, the robot being slidably positioned on the moving track, the robot being configured to pick and place the heavy mass.

4. The multi-layer gravity energy storage system according to claim 1, wherein the lifting unit and the lowering unit each comprise a power generation and electric integration machine, a transmission assembly and a transportation rail, and the transmission assembly is connected with the weight block; in the lifting unit, the transmission assembly lifts the heavy object blocks along the transportation track under the action of the power generation and electric integrated machine; in the descending unit, the transmission assembly descends along the transportation rail under the action of the power generation and electric integrated machine.

5. The multi-layer gravity energy storage system according to claim 4, wherein the transmission assembly is a transmission chain or a pulley block.

6. A method for storing energy in a multi-layer gravity energy storage system, which is implemented by the multi-layer gravity energy storage system as claimed in any one of claims 1 to 5, and comprises:

when energy storage or energy release is carried out, according to the Mh, the aim of finding path optimization is achieved, and the number of heavy blocks to be transported and the distance of each heavy block to be operated in each lifting unit or each descending unit are calculated;

7. The energy storage method of the multilayer gravity energy storage system according to claim 6, wherein the load data includes wind energy Pw, solar energy Pv and power P required by the user side, and the power difference is Δ P, then Δ P ═ Pw + Pv-P |;

8. The energy storage method of the multilayer gravity energy storage system according to claim 6, wherein when the yard is m layers, the number j of the heavy objects is m, and the number i of the lifting units/the lowering units is m (m-1)/2.

9. The method of claim 8, wherein the calculating the number of the weight blocks to be transported comprises calculating the type of the weight blocks to be transported and the corresponding number of the weight blocks under each type.

10. The energy storage method of the multi-layer gravity energy storage system according to claim 8, wherein in the step of calculating the number of weight blocks to be transported and the distance each weight block needs to travel in each lifting unit or each descending unit with the aim of finding the optimal path, the constraint conditions include: the total length of travel of each kind of weight is an integral multiple of the sum of the travel distance of each kind of weight on each lifting unit/descending unit, the sum of the products of each kind of weight and the travel distance is equal to the Mh, and the sufficient supply transfer amount of each kind of weight in each layer yard is provided.