Gravity energy storage system and control method and control device thereof

Abstract

The invention provides a gravity energy storage system and a control method and device thereof. The gravity energy storage system comprises a first gravity energy storage device, a first motor, a frequency converter, a plurality of second gravity energy storage devices and a plurality of second motors. The first gravity energy storage device is connected with the first motor, and the first motor is further connected with the frequency converter; the multiple second gravity energy storage devices are connected with the multiple second motors in a one-to-one correspondence mode, and the frequency converter and the multiple second motors are connected with the power grid. The frequency converter can adjust the rotating speed of the first motor by adjusting the voltage and frequency of the first motor, the first motor, the frequency converter and the second motor are combined, accurate control over the electric power output by the whole gravity energy storage system can be achieved, and the frequency supporting capacity of the gravity energy storage system is further improved. According to the invention, the problem of energy loss caused by common output of the plurality of second motors is solved, and the energy efficiency of the gravity energy storage system is further improved.

Description

Technical Field

[0001] The present application relates to the technical field of power systems, and in particular to a gravity energy storage system and a control method and a control device thereof. Background Art

[0002] With the adjustment of energy structure, the proportion of new energy power generation such as photovoltaic and wind power has gradually increased. Due to the volatility and instability of new energy power generation, new energy power generation usually needs to use energy storage technologies such as gravity energy storage systems to form a joint power generation system.

[0003] In the gravity energy storage system provided by the related technology, the gravity energy storage device is connected to the power grid through a motor. The gravity energy storage device outputs mechanical power through the gravitational potential energy of multiple weights, and the motor can convert the mechanical power into electrical power and transmit it to the power grid. Usually, the mechanical power can be adjusted by controlling the number of weights, thereby achieving the adjustment of the electrical power output by the motor. However, due to the fixed speed of the synchronous generator, the output electrical power of the gravity energy storage system cannot be accurately controlled. Summary of the invention

[0004] In order to solve the problem in the prior art that the output power of the gravity energy storage system cannot be accurately controlled, the present application provides a gravity energy storage system, which may include a first gravity energy storage device, a first motor, a frequency converter, multiple second gravity energy storage devices and multiple second motors.

[0005] The first gravity energy storage device is connected to the first motor, and the first motor is also connected to the frequency converter; the plurality of second gravity energy storage devices are connected to the plurality of second motors in a one-to-one correspondence, and the frequency converter and the plurality of second motors are all connected to the power grid.

[0006] The first gravity energy storage device is used to output a first mechanical power to the first motor.

[0007] The first motor is used to convert the first mechanical power into the first electrical power and transmit the first electrical power to the frequency converter.

[0008] The frequency converter is used to: adjust the rotation speed of the first motor by adjusting the voltage and frequency of the first motor; and also to transmit the first electric power to the power grid.

[0009] The second gravity energy storage device is used to output the second mechanical power to the second motor.

[0010] The second electric machine is used to convert the second mechanical power into second electrical power and transmit the second electrical power to the power grid.

[0011] Optionally, the second motor is a synchronous generator. The first motor is a synchronous generator or an asynchronous generator. The frequency converter may be a four-quadrant frequency converter.

[0012] In some possible implementations, the first gravity energy storage device and the second gravity energy storage device both include a load-bearing tower, a towing device, and a plurality of weight blocks; the towing device is fixed on the load-bearing tower.

[0013] The traction device is used to: store gravitational potential energy by lifting the weight block, and also to convert the gravitational potential energy into the first mechanical power / the second mechanical power and output it by releasing the weight block.

[0014] On the other hand, the application also provides a control method for a gravity energy storage system, including: determining the number of weight blocks mounted on each second gravity energy storage device according to the mass of a single weight block in the second gravity energy storage device in the gravity energy storage system. Calculating the electric power required to be output by the first motor in the gravity energy storage system according to the mass of the single weight block, and adjusting the speed of the first motor according to the electric power required to be output by the first motor. Adjusting the electric power actually output by the first motor according to the adjusted speed of the first motor, and determining the electric power actually output by the second motor in the gravity energy storage system according to the number of weight blocks mounted on each second gravity energy storage device.

[0015] In some possible implementations, the number of weight blocks mounted on each second gravity energy storage device is determined based on the mass of a single weight block in the second gravity energy storage device in the gravity energy storage system, including: calculating the required output power of the gravity energy storage system and the number of second motors to be started based on the frequency change of the power grid. The number of weight blocks mounted on each second gravity energy storage device is determined based on the required output power of the gravity energy storage system and the number of second motors to be started.

[0016] In one example, the electric power required to be output by the gravity energy storage system and the number of second motors to be started are calculated according to the frequency change of the power grid, including: taking the frequency difference between the frequency after the load change of the power grid and the rated frequency of the power grid as the first frequency change of the power grid. The unit adjustment power of the load is determined according to the first frequency change of the power grid, and the electric power required to be output by the gravity energy storage system and the number of second motors to be started are calculated according to the unit adjustment power of the load.

[0017] Furthermore, the unit regulation power of the load satisfies Among them, K L Indicates the unit regulation power of the load, ΔP L represents the change in load, Δf1 represents the change in the first frequency of the power grid, satisfying Δf1=f1-f N , f1 represents the frequency of the power grid after load changes, f N Indicates the rated frequency of the power grid.

[0018] The electric power required to be output by the gravity energy storage system and the number of second motors to be started meet the following requirements:

[0019]

[0020]

[0021] Where ΔP G represents the electric power required to be output by the gravity energy storage system, N represents the number of second motors that need to be started; Δf2 represents the change in the regulation frequency of the power grid, Δf2=f2-f1, f2 represents the frequency of the power grid after transient stabilization; K g Indicates the unit regulation power of the second motor.

[0022] In another example, the number of weight blocks mounted on each second gravity energy storage device is determined according to the electric power required to be output by the gravity energy storage system and the number of second motors required to be started, including: calculating the number of weight blocks that need to be adjusted according to the electric power required to be output by the gravity energy storage system. Determining the number of mass blocks mounted on each second gravity energy storage device according to the number of weight blocks that need to be changed.

[0023] Furthermore, the number of weight blocks that need to be adjusted satisfies Among them, Δk s Indicates the number of weights that need to be adjusted, [] indicates rounding, ΔP G represents the electric power required by the gravity energy storage system, m represents the mass of a single weight, g represents the acceleration of gravity, v n Indicates the rated operating speed of the weight block.

[0024] Optionally, determining the number of mass blocks mounted on each second gravity energy storage device according to the number of weight blocks that needs to be changed includes:

[0025] When the number of weight blocks that need to be changed is greater than 0, increase the number of weight blocks mounted on the first second gravity energy storage device until the number of weight blocks mounted on the first second gravity energy storage device reaches the maximum value, and then increase the number of weight blocks mounted on other second gravity energy storage devices in turn.

[0026] When the number of weight blocks that need to be changed is less than 0, reduce the number of weight blocks mounted on the last second gravity energy storage device until the number of weight blocks mounted on the last second gravity energy storage device is 0, and then reduce the number of weight blocks mounted on other second gravity energy storage devices in turn.

[0027] In some possible implementations, the electric power required to be output by the first motor may satisfy ΔP1=ΔP G -mgv n Δk s Among them, ΔP1 represents the electric power required to be output by the first motor, ΔP G represents the electric power required by the gravity energy storage system, m represents the mass of a single weight, g represents the acceleration of gravity, vn Indicates the rated running speed of the weight block, Δk s Indicates the number of weights that need to be adjusted.

[0028] In some other possible implementations, adjusting the speed of the first motor according to the electric power required to be output by the first motor in the gravity energy storage system includes:

[0029] When the actual electric power output by the first motor is less than the electric power required to be output by the first motor, the rotation speed of the first motor is increased.

[0030] When the actual electric power output by the first motor is greater than the electric power required to be output by the first motor, the rotation speed of the first motor is reduced.

[0031] On the other hand, the application also provides a control device for a gravity energy storage system, including a determination module, a regulation module and a control module.

[0032] Optionally, the determination module is used to determine the number of weight blocks mounted on each second gravity energy storage device according to the mass of a single weight block in the second gravity energy storage device in the gravity energy storage system.

[0033] The regulating module is used to calculate the electric power required to be output by the first motor in the gravity energy storage system according to the mass of a single weight block, and to regulate the rotation speed of the first motor according to the electric power required to be output by the first motor.

[0034] The control module is used to adjust the electric power actually output by the first motor according to the adjusted speed of the first motor, and determine the electric power actually output by the second motor in the gravity energy storage system according to the number of weight blocks mounted on each second gravity energy storage device.

[0035] Optionally, the determination module is specifically used to: calculate the electric power required to be output by the gravity energy storage system and the number of second motors to be started according to the frequency change of the power grid. Determine the number of weight blocks mounted on each second gravity energy storage device according to the electric power required to be output by the gravity energy storage system and the number of second motors to be started.

[0036] In one example, the determination module is specifically used to: take the frequency difference between the frequency of the power grid after the load change and the rated frequency of the power grid as the first frequency change of the power grid. Determine the unit adjustment power of the load according to the first frequency change of the power grid, and calculate the electric power required to be output by the gravity energy storage system and the number of second motors that need to be started according to the unit adjustment power of the load.

[0037] Optionally, the unit regulation power of the load meets Among them, K L Indicates the unit regulation power of the load, ΔP Lrepresents the change in load, Δf1 represents the change in the first frequency of the power grid, satisfying Δf1=f1-f N , f1 represents the frequency of the power grid after load changes, f N Indicates the rated frequency of the power grid.

[0038] The electric power required to be output by the gravity energy storage system and the number of second motors to be started meet the following requirements:

[0039]

[0040] Among them, ΔP G represents the electric power required to be output by the gravity energy storage system, N represents the number of second motors that need to be started; Δf2 represents the change in the regulation frequency of the power grid, Δf2=f2-f1, f2 represents the frequency of the power grid after transient stabilization; K g Indicates the unit regulation power of the second motor.

[0041] In another example, the determination module is specifically used to: calculate the number of weight blocks that need to be adjusted according to the electric power required to be output by the gravity energy storage system, and determine the number of mass blocks mounted on each second gravity energy storage device according to the number of weight blocks that need to be changed.

[0042] Optionally, the number of weights to be adjusted meets Among them, Δk s Indicates the number of weights that need to be adjusted, [] indicates rounding, ΔP G represents the electric power required by the gravity energy storage system, m represents the mass of a single weight, g represents the acceleration of gravity, v n Indicates the rated operating speed of the weight block.

[0043] Furthermore, the module is specifically used to:

[0044] When the number of weight blocks that need to be changed is greater than 0, increase the number of weight blocks mounted on the first second gravity energy storage device until the number of weight blocks mounted on the first second gravity energy storage device reaches the maximum value, and then increase the number of weight blocks mounted on other second gravity energy storage devices in turn.

[0045] When the number of weight blocks that need to be changed is less than 0, reduce the number of weight blocks mounted on the last second gravity energy storage device until the number of weight blocks mounted on the last second gravity energy storage device is 0, and then reduce the number of weight blocks mounted on other second gravity energy storage devices in turn.

[0046] For example, the electric power required to be output by the first motor satisfies ΔP1=ΔP G -mgv n Δk s; Wherein, ΔP1 represents the electric power required to be output by the first motor, ΔP G represents the electric power required by the gravity energy storage system, m represents the mass of a single weight, g represents the acceleration of gravity, v n Indicates the rated running speed of the weight block, Δk s Indicates the number of weights that need to be adjusted.

[0047] Optionally, the adjustment module is specifically used for:

[0048] When the actual electric power output by the first motor is less than the electric power required to be output by the first motor, the rotation speed of the first motor is increased.

[0049] When the actual electric power output by the first motor is greater than the electric power required to be output by the first motor, the rotation speed of the first motor is reduced.

[0050] On the other hand, the present application also provides a computer device, including: one or more processors.

[0051] A processor is used to execute one or more programs.

[0052] When one or more programs are executed by one or more processors, the control method as described above is implemented.

[0053] In another aspect, the present application further provides a computer-readable storage medium having a computer program stored thereon. When the computer program is executed, the control method described above is implemented.

[0054] Compared with the prior art, the beneficial effects of this application are:

[0055] In the gravity energy storage system provided by the present application, the first motor can be connected to the power grid through a frequency converter, and the second motor can be directly connected to the AC power grid. The frequency converter can adjust the speed of the first motor by adjusting the voltage and frequency of the first motor. Combining the first motor, the frequency converter and the second motor, the precise control of the electric power output by the entire gravity energy storage system can be achieved, that is, the precise control of the gravity energy storage system is improved.

[0056] The control method provided in the present application adjusts the frequency of the gravity energy storage system to determine the energy deficit of the power grid, thereby achieving precise control of the electric power output by the gravity energy storage system and further improving the frequency support capability of the gravity energy storage system.

[0057] The present application realizes the number of second motors for zero-difference regulation of the grid frequency according to the change of the grid frequency and the change of the unit regulation power of the gravity energy storage system, solves the energy loss problem caused by the joint output of multiple second motors, and further improves the energy efficiency of the gravity energy storage system. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] In order to more clearly illustrate the technical solutions in the present application or the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0059] Figure 1 A schematic structural diagram of a gravity energy storage system in an embodiment of the present application;

[0060] Figure 2 A schematic flow chart of a control method of a gravity energy storage system in an embodiment of the present application;

[0061] Figure 3 A schematic diagram of a frequency change curve of a gravity energy storage system before and after adopting the control method provided in an embodiment of the present application;

[0062] Figure 4 It is a schematic structural diagram of a control device of a gravity energy storage system in an embodiment of the present application. DETAILED DESCRIPTION

[0063] The technical solution in this application will be described below in conjunction with the accompanying drawings.

[0064] The terms "first", "second", etc. in the specification embodiments, claims, and drawings of the present application are only used for the purpose of distinguishing descriptions, and cannot be understood as indicating or implying relative importance, nor can they be understood as indicating or implying order. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, including a series of steps or units. The method, system, product, or device is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products, or devices.

[0065] It should be understood that in the present application, "at least one (item)" means one or more, and "plurality" means two or more. "And / or" is used to describe the association relationship of associated objects, indicating that three relationships may exist. For example, "A and / or B" can mean: only A exists, only B exists, and A and B exist at the same time, where A and B can be singular or plural. The character " / " generally indicates that the objects associated before and after are in an "or" relationship. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single or plural items. For example, at least one of a, b or c can mean: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, c can be single or multiple.

[0066] Embodiment 1:

[0067] The present application embodiment provides a gravity energy storage system, such as Figure 1 As shown. The gravity energy storage system 100 may include a first gravity energy storage device 11, a first motor MG12, an inverter 13, a plurality of second gravity energy storage devices 14 and a plurality of second motors 15. Among them, the plurality of second gravity energy storage devices 14 may include a second gravity energy storage device 141, a second gravity energy storage device 142, ..., a second gravity energy storage device 14N. The plurality of second motors 15 may include a plurality of second motors MG151, a second motor MG152, ..., a second motor MG15N.

[0068] The first gravity energy storage device 11 is connected to the first motor MG12, which is also connected to the inverter 13. The second gravity energy storage devices 14 are connected to the second motors 15 in a one-to-one correspondence, and the inverter 13 and the second motors 15 are connected to the power grid S.

[0069] The first gravity energy storage device 11 is used to output a first mechanical power to the first motor MG12 .

[0070] The first motor MG12 is used to convert the first mechanical power into the first electrical power and transmit the first electrical power to the inverter 13 .

[0071] The frequency converter 13 is used to adjust the speed of the first motor MG12 by adjusting the voltage and frequency of the first motor MG12. The frequency converter 13 is also used to transmit the first electric power to the power grid S.

[0072] Each second gravity energy storage device (eg, the second gravity energy storage device 141 ) is used to output a second mechanical power to a corresponding second motor (eg, the second motor MG151 ).

[0073] The second motor (for example, the second motor MG151 ) is used to convert the second mechanical power into the second electrical power and transmit the second electrical power to the grid S.

[0074] It can be understood that the frequency converter 13 and the plurality of second motors 15 can be connected to an AC bus, and the AC bus is connected to the power grid S via a transformer.

[0075] Optionally, the second motor (eg, the second motor MG151) is a synchronous generator. The first motor MG12 is a synchronous generator or an asynchronous generator. The inverter 13 may be a four-quadrant inverter.

[0076] In some possible implementations, the first gravity energy storage device 11 and the second gravity energy storage device (eg, the second gravity energy storage device 141) both include a load-bearing tower, a traction device, and a plurality of weight blocks. The traction device is fixed on the load-bearing tower.

[0077] The traction device is used to: store gravitational potential energy by lifting the weight block, and also to convert the gravitational potential energy into the first mechanical power / the second mechanical power and output it by releasing the weight block.

[0078] Embodiment 2:

[0079] The present application also provides a control method for the gravity energy storage system. Figure 2 The control method 200 comprises the following steps:

[0080] Step S1: Determine the number of weight blocks mounted on each second gravity energy storage device according to the mass of a single weight block in the second gravity energy storage device.

[0081] Step S2: Calculate the electric power required to be output by the first motor according to the mass of a single weight block, and adjust the rotation speed of the first motor according to the electric power required to be output by the first motor.

[0082] Step S3: adjusting the electric power actually output by the first motor according to the adjusted rotational speed of the first motor, and determining the electric power actually output by the second motor according to the number of weight blocks mounted on each second gravity energy storage device.

[0083] In some embodiments, in step S1, determining the number of weight blocks mounted on each second gravity energy storage device according to the mass of a single weight block in the second gravity energy storage device includes:

[0084] Step S1a: Calculate the electric power required to be output by the gravity energy storage system and the number of second motors that need to be started according to the frequency change of the power grid.

[0085] Specifically, step S1a can be implemented according to the following process:

[0086] The frequency difference between the frequency after the load change of the power grid and the rated frequency of the power grid is taken as the first frequency change of the power grid. The unit adjustment power of the load is determined according to the first frequency change of the power grid, and the electric power required to be output by the gravity energy storage system and the number of second motors required to be started are calculated according to the unit adjustment power of the load.

[0087] Optionally, the unit regulation power of the load meets Among them, K L Indicates the unit regulation power of the load, ΔP L represents the change in load, Δf1 represents the change in the first frequency of the power grid, satisfying Δf1=f1-f N , f1 represents the frequency of the power grid after load changes, f N Indicates the rated frequency of the power grid.

[0088] The electric power required to be output by the gravity energy storage system and the number of second motors to be started meet the following requirements:

[0089]

[0090] Where ΔP G represents the electric power required to be output by the gravity energy storage system, N represents the number of second motors that need to be started; Δf2 represents the change in the regulation frequency of the power grid, Δf2=f2-f1, f2 represents the frequency of the power grid after transient stabilization; K g Indicates the unit regulation power of the second motor.

[0091] Step S1b: Determine the number of weight blocks mounted on each second gravity energy storage device according to the electric power required to be output by the gravity energy storage system and the number of second motors that need to be started.

[0092] Specifically, step S1b can be implemented according to the following process:

[0093] Step S1b1: Calculate the number of weight blocks that need to be adjusted according to the electric power required to be output by the gravity energy storage system.

[0094] Among them, the number of weight blocks that need to be adjusted meets Among them, Δk s Indicates the number of weights that need to be adjusted, [] indicates rounding, ΔP G represents the electric power required by the gravity energy storage system, m represents the mass of a single weight, g represents the acceleration of gravity, v n Indicates the rated operating speed of the weight block.

[0095] Step S1b2: Determine the number of mass blocks mounted on each second gravity energy storage device according to the number of weight blocks that need to be changed. This can be divided into the following two situations:

[0096] When the number of weight blocks that need to be changed is greater than 0, increase the number of weight blocks mounted on the first second gravity energy storage device until the number of weight blocks mounted on the first second gravity energy storage device reaches the maximum value, and then increase the number of weight blocks mounted on other second gravity energy storage devices in turn.

[0097] When the number of weight blocks that need to be changed is less than 0, reduce the number of weight blocks mounted on the last second gravity energy storage device until the number of weight blocks mounted on the last second gravity energy storage device is 0, and then reduce the number of weight blocks mounted on other second gravity energy storage devices in turn.

[0098] In some possible implementations, the electric power required to be output by the first motor may satisfy ΔP1=ΔP G -mgv n Δk sAmong them, ΔP1 represents the electric power required to be output by the first motor, ΔP G represents the electric power required by the gravity energy storage system, m represents the mass of a single weight, g represents the acceleration of gravity, v n Indicates the rated running speed of the weight block, Δk s Indicates the number of weights that need to be adjusted.

[0099] In the above step S2, adjusting the speed of the first motor according to the electric power required to be output by the first motor can be divided into the following two cases:

[0100] When the actual electric power output by the first motor is less than the electric power required to be output by the first motor, the rotation speed of the first motor is increased.

[0101] When the actual electric power output by the first motor is greater than the electric power required to be output by the first motor, the rotation speed of the first motor is reduced.

[0102] Take the gravity energy storage system including one first motor and two second motors as an example. The capacity of each motor is 6.5MW. In the initial state, each motor carries 5 weight blocks. When it is set to 20s, the load of the power grid increases by 400kW.

[0103] Before the control method provided in the embodiment of the present application is used to control the gravity energy storage system, the rated frequency f of the power grid is N After the gravity energy storage system is controlled by the control method provided in the embodiment of the present application, the frequency f1 of the power grid after the load change is 50.24Hz, and the frequency f2 of the power grid after the transient stabilization is 49.939Hz. The frequency change curve of the gravity energy storage system is shown in FIG. Figure 3 shown. Figure 3 In the figure, the dotted line represents the frequency change curve of the gravity energy storage system before the control method provided in the embodiment of the present application is used to control the gravity energy storage system, and the solid line represents the frequency change curve of the gravity energy storage system after the control method provided in the embodiment of the present application is used to control the gravity energy storage system.

[0104] from Figure 3 It can be seen that the control method provided in the embodiment of the present application can control the frequency of the gravity energy storage system to be close to the rated frequency of the power grid. That is, the embodiment of the present application can achieve precise control of the output power of the gravity energy storage system by adjusting the frequency of the gravity energy storage system.

[0105] Embodiment 3:

[0106] The present application also provides a control device for the gravity energy storage system. Figure 4The control device 300 may include a determination module 301 , an adjustment module 302 and a control module 303 .

[0107] Optionally, the determination module 301 is used to determine the number of weight blocks mounted on each second gravity energy storage device according to the mass of a single weight block in the second gravity energy storage device.

[0108] The adjustment module 302 is used to calculate the electric power required to be output by the first motor according to the mass of a single weight block, and adjust the rotation speed of the first motor according to the electric power required to be output by the first motor.

[0109] The control module 303 is used to adjust the electric power actually output by the first motor according to the adjusted rotation speed of the first motor, and determine the electric power actually output by the second motor according to the number of weight blocks mounted on each second gravity energy storage device.

[0110] Optionally, the determination module 301 is specifically used to: calculate the electric power required to be output by the gravity energy storage system and the number of second motors to be started according to the frequency change of the power grid. Determine the number of weight blocks mounted on each second gravity energy storage device according to the electric power required to be output by the gravity energy storage system and the number of second motors to be started.

[0111] In one example, the determination module 301 is specifically used to: use the frequency difference between the frequency of the power grid after the load change and the rated frequency of the power grid as the first frequency change of the power grid. Determine the unit adjustment power of the load according to the first frequency change of the power grid, and calculate the electric power required to be output by the gravity energy storage system and the number of second motors that need to be started according to the unit adjustment power of the load.

[0112] Optionally, the unit regulation power of the load meets Among them, K L Indicates the unit regulation power of the load, ΔP L represents the change in load, Δf1 represents the change in the first frequency of the power grid, satisfying Δf1=f1-f N , f1 represents the frequency of the power grid after load changes, f N Indicates the rated frequency of the power grid.

[0113] The electric power required to be output by the gravity energy storage system and the number of second motors to be started meet the following requirements:

[0114]

[0115] Where ΔP G represents the electric power required to be output by the gravity energy storage system, N represents the number of second motors that need to be started; Δf2 represents the change in the regulation frequency of the power grid, Δf2=f2-f1, f2 represents the frequency of the power grid after transient stabilization; K gIndicates the unit regulation power of the second motor.

[0116] In another example, the determination module 301 is specifically used to: calculate the number of weight blocks that need to be adjusted according to the electric power required to be output by the gravity energy storage system, and determine the number of mass blocks mounted on each second gravity energy storage device according to the number of weight blocks that need to be changed.

[0117] Optionally, the number of weights to be adjusted meets Among them, Δk s Indicates the number of weights that need to be adjusted, [] indicates rounding, ΔP G represents the electric power required by the gravity energy storage system, m represents the mass of a single weight, g represents the acceleration of gravity, v n Indicates the rated operating speed of the weight block.

[0118] Furthermore, the determination module 301 is specifically used for:

[0119] When the number of weight blocks that need to be changed is greater than 0, increase the number of weight blocks mounted on the first second gravity energy storage device until the number of weight blocks mounted on the first second gravity energy storage device reaches the maximum value, and then increase the number of weight blocks mounted on other second gravity energy storage devices in turn.

[0120] When the number of weight blocks that need to be changed is less than 0, reduce the number of weight blocks mounted on the last second gravity energy storage device until the number of weight blocks mounted on the last second gravity energy storage device is 0, and then reduce the number of weight blocks mounted on other second gravity energy storage devices in turn.

[0121] For example, the electric power required to be output by the first motor satisfies ΔP1=ΔP G -mgv n Δk s ; Wherein, ΔP1 represents the electric power required to be output by the first motor, ΔP G represents the electric power required by the gravity energy storage system, m represents the mass of a single weight, g represents the acceleration of gravity, v n Indicates the rated running speed of the weight block, Δk s Indicates the number of weights that need to be adjusted.

[0122] Optionally, the adjustment module 302 is specifically configured to:

[0123] When the actual electric power output by the first motor is less than the electric power required to be output by the first motor, the rotation speed of the first motor is increased.

[0124] When the actual electric power output by the first motor is greater than the electric power required to be output by the first motor, the rotation speed of the first motor is reduced.

[0125] Embodiment 4:

[0126] Based on the same inventive concept, the embodiment of the present application also provides a computer device, which includes a processor and a memory, the memory is used to store a computer program, the computer program includes program instructions, and the processor is used to execute the program instructions stored in a computer storage medium. The processor may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components, etc., which are the computing core and control core of the terminal, which are suitable for implementing one or more instructions, and are specifically suitable for loading and executing one or more instructions in a computer storage medium to implement the corresponding method flow or corresponding functions, so as to implement the steps of the control method provided in the above embodiment.

[0127] Embodiment 5:

[0128] Based on the same inventive concept, the embodiment of the present application also provides a storage medium, specifically a computer-readable storage medium (Memory), which is a memory device in a computer device for storing programs and data. It is understandable that the computer-readable storage medium here can include both built-in storage media in a computer device and, of course, an extended storage medium supported by the computer device. The computer-readable storage medium provides a storage space, which stores the operating system of the terminal. In addition, one or more instructions suitable for being loaded and executed by a processor are also stored in the storage space, and these instructions can be one or more computer programs (including program codes). It should be noted that the computer-readable storage medium here can be a high-speed RAM memory or a non-volatile memory, such as at least one disk memory. The processor can load and execute one or more instructions stored in the computer-readable storage medium to implement the steps of the control method provided in the above embodiment.

[0129] Those skilled in the art will appreciate that the embodiments of the application may be provided as methods, systems, or computer program products. Therefore, the application may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the application may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0130] The application is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the application. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0131] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0132] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0133] The above are merely embodiments of the application and are not intended to limit the application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the application are included in the scope of the claims of the pending application.

Claims

1. A gravity energy storage system, characterized in that: It includes a first gravity energy storage device, a first motor, a frequency converter, a plurality of second gravity energy storage devices and a plurality of second motors; Wherein, the first gravity energy storage device is connected to the first motor, and the first motor is also connected to the frequency converter; the plurality of second gravity energy storage devices are connected to the plurality of second motors one by one, and the frequency converter and the plurality of second motors are both connected to the power grid; The first gravity energy storage device is used to: output a first mechanical power to the first motor; The first motor is used to: convert the first mechanical power into first electrical power and transmit it to the frequency converter; The frequency converter is used to: adjust the speed of the first motor by adjusting the voltage and frequency of the first motor; and is also used to transmit the first electric power to the power grid; The second gravity energy storage device is used to: output a second mechanical power to the second motor; The second electric machine is used for converting the second mechanical power into second electrical power and transmitting the second electrical power to the power grid.

2. The gravity energy storage system according to claim 1, characterized in that: The second motor is a synchronous generator; The first motor is a synchronous generator or an asynchronous generator; The frequency converter is a four-quadrant frequency converter.

3. The gravity energy storage system according to claim 1, characterized in that: The first gravity energy storage device and the second gravity energy storage device each include a load-bearing tower, a dragging device and a plurality of weight blocks; the dragging device is fixed on the load-bearing tower; The traction device is used to store gravitational potential energy by lifting the weight block, and is also used to convert the gravitational potential energy into the first mechanical power / the second mechanical power and output it by releasing the weight block.

4. A control method for a gravity energy storage system, characterized in that: include: Determining the number of weight blocks mounted on each second gravity energy storage device according to the mass of a single weight block in the second gravity energy storage device in the gravity energy storage system; Calculating the electric power required to be output by the first motor in the gravity energy storage system according to the mass of the single weight block, and adjusting the speed of the first motor according to the electric power required to be output by the first motor; The electric power actually output by the first motor is adjusted according to the adjusted rotation speed of the first motor, and the electric power actually output by the second motor in the gravity energy storage system is determined according to the number of weight blocks mounted on each second gravity energy storage device.

5. The control method according to claim 4, characterized in that: The method of determining the number of weight blocks mounted on each second gravity energy storage device according to the mass of a single weight block in the second gravity energy storage device in the gravity energy storage system comprises: Calculating the electric power required to be output by the gravity energy storage system and the number of second motors required to be started according to the frequency change of the power grid; The number of weight blocks mounted on each second gravity energy storage device is determined according to the electric power required to be output by the gravity energy storage system and the number of second motors that need to be started.

6. The control method according to claim 5, characterized in that: The step of calculating the electric power required to be output by the gravity energy storage system and the number of second motors required to be started according to the frequency change of the power grid includes: Taking the frequency difference between the frequency of the power grid after the load change and the rated frequency of the power grid as the first frequency change of the power grid; The unit adjustment power of the load is determined according to the first frequency change of the power grid, and the electric power required to be output by the gravity energy storage system and the number of second motors required to be started are calculated according to the unit adjustment power of the load.

7. The control method according to claim 6, characterized in that: The unit regulation power of the load satisfies Among them, K L represents the unit regulation power of the load, ΔP L represents the load change, Δf1 represents the first frequency change of the power grid, and satisfies Δf1=f1-f N , f1 represents the frequency of the power grid after the load changes, f N represents the rated frequency of the power grid; The electric power required to be output by the gravity energy storage system and the number of second motors required to be started respectively satisfy: Among them, ΔP G represents the electric power required to be output by the gravity energy storage system, N represents the number of second motors that need to be started; Δf2 represents the change in the adjustment frequency of the power grid, Δf2=f2-f1, f2 represents the frequency of the power grid after transient stabilization; K g Represents the unit regulation power of the second motor.

8. The control method according to claim 5, characterized in that: The method of determining the number of weight blocks mounted on each second gravity energy storage device according to the electric power required to be output by the gravity energy storage system and the number of second motors required to be started includes: Calculating the number of weight blocks that need to be adjusted according to the electric power required to be output by the gravity energy storage system; The number of mass blocks mounted on each second gravity energy storage device is determined according to the number of weight blocks that need to be changed.

9. The control method according to claim 8, characterized in that: The number of weight blocks that need to be adjusted meets Among them, Δk s Indicates the number of weights that need to be adjusted, [] indicates rounding, ΔP G represents the electric power required to be output by the gravity energy storage system, m represents the mass of the single weight block, g represents the gravitational acceleration, v n Indicates the rated operating speed of the weight block.

10. The control method according to claim 8, characterized in that: The step of determining the number of mass blocks mounted on each second gravity energy storage device according to the number of weight blocks that needs to be changed includes: In the case where the number of weight blocks that need to be changed is greater than 0, the number of weight blocks mounted on the first second gravity energy storage device is increased until the number of weight blocks mounted on the first second gravity energy storage device reaches a maximum value, and then the number of weight blocks mounted on other second gravity energy storage devices is increased in sequence; When the number of weight blocks that need to be changed is less than 0, reduce the number of weight blocks mounted on the last second gravity energy storage device until the number of weight blocks mounted on the last second gravity energy storage device is 0, and then reduce the number of weight blocks mounted on other second gravity energy storage devices in turn.

11. The control method according to claim 4, characterized in that: The electric power required to be output by the first motor satisfies ΔP1=ΔP G -mgv n Δk s ; Wherein, ΔP1 represents the electric power required to be output by the first motor, ΔP G represents the electric power required to be output by the gravity energy storage system, m represents the mass of the single weight block, g represents the gravitational acceleration, v n Indicates the rated running speed of the weight block, Δk s Indicates the number of weights that need to be adjusted.

12. The control method according to claim 4, characterized in that: The adjusting the speed of the first motor according to the electric power required to be output by the first motor comprises: When the actual electric power output by the first motor is less than the electric power required to be output by the first motor, increasing the rotation speed of the first motor; When the actual electric power output by the first motor is greater than the electric power required to be output by the first motor, the rotation speed of the first motor is reduced.

13. A control device for a gravity energy storage system, characterized in that: include: A determination module, used to determine the number of weight blocks mounted on each second gravity energy storage device according to the mass of a single weight block in the second gravity energy storage device in the gravity energy storage system; A regulating module, used for calculating the electric power required to be output by the first motor in the gravity energy storage system according to the mass of the single weight block, and regulating the speed of the first motor according to the electric power required to be output by the first motor; The control module is used to adjust the electric power actually output by the first motor according to the adjusted rotational speed of the first motor, and determine the electric power actually output by the second motor in the gravity energy storage system according to the number of weight blocks mounted on each second gravity energy storage device.

14. The control device according to claim 13, characterized in that: The determination module is specifically used for: Calculating the electric power required to be output by the gravity energy storage system and the number of second motors required to be started according to the frequency change of the power grid; The number of weight blocks mounted on each second gravity energy storage device is determined according to the electric power required to be output by the gravity energy storage system and the number of second motors that need to be started.

15. The control device according to claim 14, characterized in that: The determination module is specifically used for: Taking the frequency difference between the frequency of the power grid after the load change and the rated frequency of the power grid as the first frequency change of the power grid; The unit adjustment power of the load is determined according to the first frequency change of the power grid, and the electric power required to be output by the gravity energy storage system and the number of second motors required to be started are calculated according to the unit adjustment power of the load.

16. The control device according to claim 15, characterized in that: The unit regulation power of the load satisfies Among them, K L represents the unit regulation power of the load, ΔP L represents the load change, Δf1 represents the first frequency change of the power grid, and satisfies Δf1=f1-f N , f1 represents the frequency of the power grid after the load changes, f N represents the rated frequency of the power grid; The electric power required to be output by the gravity energy storage system and the number of second motors required to be started respectively satisfy: Among them, ΔP G represents the electric power required to be output by the gravity energy storage system, N represents the number of second motors that need to be started; Δf2 represents the change in the adjustment frequency of the power grid, Δf2=f2-f1, f2 represents the frequency of the power grid after transient stabilization; K g Represents the unit regulation power of the second motor.

17. The control device according to claim 14, characterized in that: The determination module is specifically used for: Calculating the number of weight blocks that need to be adjusted according to the electric power required to be output by the gravity energy storage system; The number of mass blocks mounted on each second gravity energy storage device is determined according to the number of weight blocks that need to be changed.

18. The control device according to claim 17, characterized in that: The number of weight blocks that need to be adjusted meets Among them, Δk s Indicates the number of weights that need to be adjusted, [] indicates rounding, ΔP G represents the electric power required to be output by the gravity energy storage system, m represents the mass of the single weight block, g represents the gravitational acceleration, v n Indicates the rated operating speed of the weight block.

19. The control device according to claim 17, characterized in that: The determination module is specifically used for: In the case where the number of weight blocks that need to be changed is greater than 0, the number of weight blocks mounted on the first second gravity energy storage device is increased until the number of weight blocks mounted on the first second gravity energy storage device reaches a maximum value, and then the number of weight blocks mounted on other second gravity energy storage devices is increased in sequence; When the number of weight blocks that need to be changed is less than 0, reduce the number of weight blocks mounted on the last second gravity energy storage device until the number of weight blocks mounted on the last second gravity energy storage device is 0, and then reduce the number of weight blocks mounted on other second gravity energy storage devices in turn.

20. The control device according to claim 13, characterized in that: The electric power required to be output by the first motor satisfies ΔP1=ΔP G -mgv n Δk s ; Wherein, ΔP1 represents the electric power required to be output by the first motor, ΔP G represents the electric power required to be output by the gravity energy storage system, m represents the mass of the single weight block, g represents the gravitational acceleration, v n Indicates the rated running speed of the weight block, Δk s Indicates the number of weights that need to be adjusted.

21. The control device according to claim 13, characterized in that: The adjustment module is specifically used for: When the actual electric power output by the first motor is less than the electric power required to be output by the first motor, increasing the rotation speed of the first motor; When the actual electric power output by the first motor is greater than the electric power required to be output by the first motor, the rotation speed of the first motor is reduced.

22. A computer device, characterized in that: include: one or more processors; The processor is used to store one or more programs; When the one or more programs are executed by the one or more processors, the control method according to any one of claims 4 to 12 is implemented.

23. A computer-readable storage medium, characterized in that: A computer program is stored thereon, and when the computer program is executed, the control method according to any one of claims 4 to 12 is implemented.

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