Gravity energy storage system based on retired wind turbine and its control method

Abstract

The present application provides a gravity energy storage system based on a retired wind turbine and a control method thereof, the gravity energy storage system includes a tower, an underground tunnel, a weight block, a winch, a motor, and a generator, the underground tunnel is arranged below the tower and is connected to the inside of the tower, the weight block is stored in the underground tunnel, the winch is installed at the top of the tower, the winch is used to connect the weight block, the motor is installed at the top of the tower, the motor is used to drive the winch to lift the weight block, the generator is installed at the top of the tower, and when the weight block falls, the winch is used to drive the generator to generate electricity. The control method can control the winch to lift or release the weight block of the required weight according to the power demand instruction to meet the energy storage or energy release requirements. The system uses the retired wind turbine tower as an energy storage platform with a height difference, and the wind turbine blades as energy storage weight blocks, which effectively solves the high processing costs of dismantling the retired wind turbine tower and recovering the wind blades, and shortens the construction cost of the gravity energy storage system.

Description

Technical Field

[0001] The present application belongs to the technical field of gravity power generation, and specifically, relates to a gravity energy storage system based on a retired wind turbine and a control method thereof. Background Art

[0002] At present, wind power generation is growing explosively, and large-scale wind turbines are gradually being retired. Wind turbine blades are a kind of thermosetting composite material. Due to the complexity of the materials used in wind turbine blades, it is still a challenge to recycle them. The retired wind turbines basically adopt the method of dismantling the tower and recycling the wind turbine blades. The tower dismantling and wind turbine blade recycling costs are high, and the cost of dismantling the wind turbine tower is also high, and the resource utilization rate is not high. At the same time, if the electricity generated by clean energy such as wind power generation is not transmitted to the power grid in time, for example, when the clean energy grid-connected power generation load exceeds the power demand of the power grid, surplus electricity will be generated. Therefore, the usual solution in the industry is to equip the corresponding energy storage system, one of which is the gravity energy storage system. The basic principle of the gravity energy storage system is to lift and lower the energy storage medium based on the height difference, so as to complete the charging and discharging process of the energy storage system. In the existing gravity energy storage solution, the heavy blocks are made of concrete, which is expensive and the manufacturing process is not environmentally friendly. At the same time, it is necessary to build an energy storage platform with a height difference, which has a long construction period and high cost, which is not conducive to the rapid promotion of energy storage gravity technology.

[0003] Therefore, how to combine retired wind turbines with gravity energy storage to solve the above problems is a direction worthy of research. Summary of the invention

[0004] The technical problem solved by this application is: how to solve both the high cost problem of recycling retired wind turbines and the high cost and environmentally unfriendly problem of building a gravity energy storage system.

[0005] The present application provides a gravity energy storage system based on a retired wind turbine, the gravity energy storage system comprising:

[0006] Tower;

[0007] An underground tunnel, the underground tunnel is arranged below the tower and communicated with the interior of the tower;

[0008] A heavy object block, wherein the heavy object block is stored in the underground tunnel;

[0009] A winch, which is installed on the top of the tower and is used to connect the weight block;

[0010] An electric motor is installed at the top of the tower, and is used to drive the winch to lift the weight block;

[0011] A generator is installed on the top of the tower, and when the weight block falls, the winch is used to drive the generator to generate electricity.

[0012] Optionally, the gravity energy storage system further includes:

[0013] A first electromagnetic clutch is installed between the winch and the motor, and is used to control the connection and disconnection between the winch and the motor.

[0014] Optionally, the gravity energy storage system further includes:

[0015] A second electromagnetic clutch is installed between the winch and the generator, and the second electromagnetic clutch is used to control the connection and disconnection between the winch and the generator.

[0016] Optionally, the weight block is formed by melting and casting blades of retired wind turbines, and the weight block is in a square shape.

[0017] Optionally, there are multiple towers, and each tower is equipped with the winch, the motor and the generator.

[0018] Optionally, the interior of each tower is connected to the underground tunnel, and the underground tunnel stores a plurality of weight blocks.

[0019] The present application provides a control method for a gravity energy storage system based on a retired wind turbine, the control method comprising:

[0020] The required weight of the heavy object block is calculated according to the obtained power demand instruction;

[0021] Establish a scheduling model based on the collected operating data of the gravity energy storage system;

[0022] Monitor the state of the gravity energy storage system and set the optimization variables and constraints of the gravity energy storage system;

[0023] The scheduling model is solved for multi-objective optimization based on demand weight, optimization variables and constraints, a scheduling plan is generated, and the scheduling plan is executed.

[0024] Optionally, the control method further includes:

[0025] Determining the required power according to the power demand instruction;

[0026] When the required power is less than the threshold power of the gravity energy storage system, ignoring the power demand instruction;

[0027] When the required power is greater than the threshold power of the gravity energy storage system, the required weight of the weight block is calculated according to the required power.

[0028] Optionally, the optimization variables include height, weight mass, running speed, and acceleration.

[0029] The present application provides a gravity energy storage system based on retired wind turbines, which has the following technical effects:

[0030] By using retired wind turbine towers as energy storage platforms with height differences and wind turbine blades as energy storage weights, the high processing costs of dismantling retired wind turbine towers and recovering wind blades can be effectively solved, resource recycling can be achieved, and at the same time, the construction period and investment cost of the gravity energy storage system can be greatly shortened. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 is a schematic diagram of a gravity energy storage system based on a retired wind turbine according to one or more embodiments;

[0032] Figure 2 The present invention is a flow chart of a control method of a gravity energy storage system based on retired wind turbines according to one or more embodiments.

[0033] The corresponding relationship between the reference numerals and the component names is as follows:

[0034] 1-electric motor, 2-first electromagnetic clutch, 3-winch, 4-second electromagnetic clutch, 5-generator, 6-wind turbine tower, 7-weight block, 8-underground tunnel. DETAILED DESCRIPTION

[0035] 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.

[0036] Before describing the various embodiments of the present application in detail, the technical concept of the present application is first briefly described: the current retired wind turbines have the problem of high demolition costs, and the gravity energy storage system is difficult to build and has high costs. To this end, the gravity energy storage system based on retired wind turbines and its control method provided by the present application use the tower of the retired wind turbine as an energy storage platform, set up an underground tunnel under the tower and store multiple weight blocks, install a winch, a motor and a generator on the top of the tower, and when storing energy, the external power grid is connected to the motor to drive the winch to lift the weight block. When releasing energy, the weight block descends and drives the generator rotor to rotate to generate electricity. This method can effectively utilize retired wind turbines as part of the energy storage system, which not only solves the high cost problem of wind turbine recycling, but also solves the high cost and environmentally unfriendly problem of gravity energy storage system construction. The specific principles of the gravity energy storage system based on retired wind turbines and its control method of the present application are described below in combination with more embodiments.

[0037] Specifically, Figure 1 As shown, the gravity energy storage system based on the retired wind turbine provided in the first embodiment includes a tower 6, an underground tunnel 8, a weight block 7, a winch 3, an electric motor 1, and a generator 5. The underground tunnel 8 is arranged below the tower 6 and is connected to the interior of the tower 6. The weight block 7 is stored in the underground tunnel 8. The winch 3 is installed at the top of the tower 6. The winch 3 is used to connect the weight block 7. The motor 5 is installed at the top of the tower 6. The motor 1 is used to drive the winch 3 to lift the weight block 7. The generator 5 is installed at the top of the tower 6. When the weight block 7 falls, the winch is used to drive the generator 5 to generate electricity.

[0038] For example, the motor 1 is connected to the winch 3, the winch 3 fixes the top of the wire rope, the tail end of the wire rope is connected to the weight block 7, and the motor 1 is connected to the external power grid for lifting the weight to complete the energy storage stage. The external power grid is clean energy such as wind energy, solar energy, hydrogen energy, etc., and the best is wind energy and photovoltaic power abandonment.

[0039] Furthermore, the weight block 7 is formed by melting and casting the blades of the retired wind turbine, and the shape of the weight block 7 is a block, for example, a rectangular parallelepiped, a cube, etc. The tower 6 uses the tower of the retired wind turbine as a gravity energy storage platform with a height difference. The tower 6, the weight block 7, the winch 3, the motor 1, and the generator 5 constitute a gravity energy storage unit.

[0040] In one or more embodiments, there are multiple towers 6, the interior of each tower 6 is connected to the underground tunnel 8, and each tower 6 is equipped with a winch 3, an electric motor 1 and a generator 5, that is, the gravity energy storage system can include multiple gravity energy storage units, and each gravity energy storage unit is connected through the underground tunnel 8 opened at the bottom of the wind turbine tower to realize the storage, transportation and sharing of heavy blocks. The gravity energy storage units can operate independently or jointly according to the power demand of the power grid.

[0041] In one or more embodiments, the gravity energy storage system further includes a first electromagnetic clutch 2 and a second electromagnetic clutch 4, wherein the first electromagnetic clutch 2 is installed between the winch 3 and the motor 1, and the first electromagnetic clutch 2 is used to control the connection and disconnection between the winch 3 and the motor 1. The second electromagnetic clutch 4 is installed between the winch 3 and the generator 5, and the second electromagnetic clutch 4 is used to control the connection and disconnection between the winch 3 and the generator 5. In the energy storage stage, the first electromagnetic clutch 2 works, the generator 5 is disconnected from the winch 3, the second electromagnetic clutch 4 is released, the generator 5 is disconnected from the winch 3, the motor 1 is connected to the external clean energy grid and lifts the weight block 7 through the winch 3, converting the electrical energy into the potential energy of the weight block 7. In the energy release stage, the second electromagnetic clutch 4 works, the generator 5 is connected to the winch 3, the first electromagnetic clutch is disconnected, the motor 1 is disconnected from the winch 3, the weight block 7 descends, and the gravity potential energy is converted into electrical energy.

[0042] In one or more embodiments, a control method for a gravity energy storage system based on a retired wind turbine includes the following steps:

[0043] Step S10: Calculating the required weight of the heavy object according to the acquired power demand instruction;

[0044] Step S20: establishing a scheduling model according to the collected operation data of the gravity energy storage system;

[0045] Step S30: monitoring the state of the gravity energy storage system and setting optimization variables and constraints of the gravity energy storage system;

[0046] Step S40: performing multi-objective optimization on the scheduling model according to the demand weight, optimization variables and constraints, generating a scheduling plan, and executing the scheduling plan.

[0047] Among them, the power demand instruction is a storage instruction or a release instruction issued by the power grid. When the clean energy grid-connected power generation load exceeds the power demand of the power grid, this system is used to store energy; when the clean energy grid-connected power generation load is lower than the power demand of the power grid, energy is released to supplement the power demand of the power grid. After obtaining the power demand instruction, the control method also includes determining the required power according to the power demand instruction; when the required power is less than the threshold power of the gravity energy storage system, ignoring the power demand instruction; when the required power is greater than the threshold power of the gravity energy storage system, the required weight of the heavy object is calculated according to the required power. By setting the threshold power, false operation is prevented, and the energy storage system only starts working when the demand of the power system reaches a certain value.

[0048] Furthermore, according to the demand, a single tower winch can be selected to connect the required weight blocks, or multiple tower winches can be selected to cooperate with each other to connect the required weight blocks. For example, if the required power is small, a single gravity energy storage unit can operate independently to complete the work; when the required power is large, multiple gravity energy storage units need to operate jointly.

[0049] Specifically, if Figure 2 As shown, the control method of the gravity energy storage system involves the control of the motor and the control of the generator. First, establish a scheduling model: In the existing model library of MATLAB / Simulink, there are a wealth of motor and generator models. Select a suitable scheduling model to establish a control model of the gravity energy storage system. Then, perform status monitoring: Real-time monitoring of the operation of the gravity energy storage system, including the weight, operating speed, operating height, system response time, operating efficiency, etc. Next, set the optimization variables: The optimization variables select parameter variables that affect the operating efficiency of the energy storage system: height h, weight block mass m, operating speed v, acceleration a. These four parameters are selected as the optimization variables of the multi-objective optimization algorithm. Set constraints: For the range of optimization parameters of the gravity energy storage system, according to the national safety regulations for mining hoists and the specification constraints of the selected equipment, the value range of the optimization parameters is selected as: h min ≤h≤h max , m min ≤m≤m max , v min ≤v≤v max , a min ≤a≤a max , select the optimal operating parameters. Finally, perform scheduling optimization: use any of the NSGA dominant sorting genetic algorithm and GA genetic algorithm in the multi-objective optimization algorithm to optimize the constraint parameter variables, obtain the optimal solution, generate a scheduling plan, and finally execute the corresponding scheduling plan.

[0050] The gravity energy storage system and control method based on retired wind turbines provided in this embodiment have the following technical effects:

[0051] (1) Based on the use of retired wind turbine towers as energy storage platforms with height differences and wind turbine blades as energy storage weights, the high processing costs of dismantling retired wind turbine towers and recovering wind blades can be effectively solved, resource recycling can be achieved, and the construction period and investment cost of the gravity energy storage system can be greatly shortened.

[0052] (2) The gravity energy storage system includes multiple energy storage units. Each energy storage unit can operate independently or in combination with multiple energy storage units. The operation mode can be adjusted according to the power demand of the power grid, solving the problem of the capacity of a single energy storage unit being limited by the internal space of the wind turbine tower. The power can be adjusted in real time according to the power demand of the power grid, thereby improving the flexibility of the energy storage system.

[0053] (3) The existence of the underground tunnel at the bottom of the wind turbine is used to store and transport heavy objects, realizing the sharing of heavy objects; on the other hand, it can effectively increase the energy storage height of the energy storage system and increase the energy storage capacity.

[0054] The specific implementation methods of the present application are described in detail above. Although some embodiments have been shown and described, those skilled in the art should understand that these embodiments can be modified and improved without departing from the principles and spirit of the present application whose scope is defined by the claims and their equivalents. These modifications and improvements should also be within the scope of protection of the present application.

Claims

1. A gravity energy storage system based on retired wind turbines, characterized in that: The gravity energy storage system comprises: Tower; An underground tunnel, the underground tunnel is arranged below the tower and communicated with the interior of the tower; A heavy object block, wherein the heavy object block is stored in the underground tunnel; A winch, the winch is installed on the top of the tower, and the winch is used to connect the weight block; An electric motor is installed on the top of the tower, and is used to drive the winch to lift the weight block; A generator is installed on the top of the tower, and when the weight block falls, the winch is used to drive the generator to generate electricity.

2. The gravity energy storage system based on retired wind turbines according to claim 1 is characterized in that: The gravity energy storage system also includes: A first electromagnetic clutch is installed between the winch and the motor, and is used to control the connection and disconnection between the winch and the motor.

3. The gravity energy storage system based on retired wind turbines according to claim 1 is characterized in that: The gravity energy storage system also includes: A second electromagnetic clutch is installed between the winch and the generator, and the second electromagnetic clutch is used to control the connection and disconnection between the winch and the generator.

4. The gravity energy storage system based on retired wind turbines according to claim 1 is characterized in that: The weight block is formed by melting and casting blades of retired fans, and the shape of the weight block is a square.

5. The gravity energy storage system based on retired wind turbines according to any one of claims 1 to 4, characterized in that: There are multiple towers, and each tower is equipped with the winch, the motor and the generator.

6. The gravity energy storage system based on retired wind turbines according to claim 5 is characterized in that: The interior of each tower is communicated with the underground tunnel, and the underground tunnel stores a plurality of weight blocks.

7. A control method for a gravity energy storage system based on a retired wind turbine according to any one of claims 1 to 6, characterized in that: The control method comprises: The required weight of the heavy object block is calculated according to the obtained power demand instruction; Establish a scheduling model based on the collected operating data of the gravity energy storage system; Monitor the state of the gravity energy storage system and set the optimization variables and constraints of the gravity energy storage system; The scheduling model is solved for multi-objective optimization based on demand weight, optimization variables and constraints, a scheduling plan is generated, and the scheduling plan is executed.

8. The control method according to claim 7, characterized in that: The control method further comprises: Determining the required power of the energy storage system according to the power demand instruction; When the required power is less than the threshold power of the gravity energy storage system, ignoring the power demand instruction; When the required power is greater than the threshold power of the gravity energy storage system, the required weight of the weight block is calculated according to the required power.

9. The control method according to claim 7, characterized in that: The optimization variables include height, weight mass, running speed, and acceleration.

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