Gravity energy storage system and method, computer equipment and storage medium

Abstract

The invention provides a gravity energy storage system and method, computer equipment and a storage medium, and the gravity energy storage system comprises a plurality of lifting energy storage power generation systems and an electrochemical energy storage system. All the lifting energy storage power generation systems and the electrochemical energy storage system are electrically connected with an alternating current power grid; all the lifting energy storage power generation systems are used for releasing electric energy to the alternating current power grid for power generation or absorbing electric energy from the alternating current power grid for energy storage; the electrochemical energy storage system is used for absorbing electric energy in the power generation process or releasing the electric energy in the energy storage process. By adopting the scheme, the fluctuation of the power of the power grid is avoided, the operation safety of power grid equipment is improved, and the economical efficiency of the power grid is improved.

Description

Technical Field

[0001] The present invention relates to the field of energy storage technology, and in particular to a gravity energy storage system, method, computer equipment and storage medium. Background Art

[0002] In the power system, gravity energy storage power stations have multiple functions such as peak-shaving and valley-filling, frequency and phase modulation, and emergency standby restart, which can significantly enhance the stability and economy of the power grid. They are especially suitable for application scenarios such as desertified areas and industrial parks. Traditional gravity energy storage power stations set up heavy object placement areas on the top and bottom floors of the building, and use cranes and heavy object cabins in the lifting channel to achieve vertical transportation of heavy objects, thereby completing the storage and recovery of electrical energy. During the energy storage process, the electric energy output by the power grid drives the crane to lift the heavy objects to the top floor, which is converted into the gravitational potential energy of the heavy objects and stored; during the power generation process, the gravitational potential energy of the heavy objects is released to drive the crane to generate electricity and feed the electric energy back to the power grid.

[0003] However, the traditional gravity energy storage system has serious power fluctuation problems during operation. This is mainly reflected in the two processes of energy storage and power generation: Energy storage operation process: When the heavy object is lifted by the crane to the top floor of the lifting channel, the crane operates at rated power; but then, in the process of transporting the heavy object from the lifting channel to the top floor of the building, and in the process of the empty load cabin descending to the bottom floor of the lifting channel and the heavy object being transported from the bottom floor of the building to the lifting channel, the crane stops operating at rated power and the electric power becomes zero. This phenomenon of sometimes operating at rated power and sometimes pausing leads to fluctuations in the power consumption from the power grid. Power generation operation process: When the heavy object is released from the top floor of the lifting channel to the bottom floor, the crane generates power at rated power; but then, in the process of transporting the heavy object from the lifting channel to the bottom floor of the building, and in the process of the empty load cabin rising to the top floor of the lifting channel and the heavy object being transported from the top floor of the building to the lifting channel, the crane stops generating power and the power generation power becomes zero. Similarly, this phenomenon of sometimes operating at rated power and sometimes pausing leads to fluctuations in power generation power. Power fluctuations not only affect the stability of the power grid, but may also cause damage to power grid equipment and reduce the economic efficiency of the power grid. Summary of the invention

[0004] In view of this, the object of the present invention is to provide a gravity energy storage system, method, computer equipment and storage medium to avoid fluctuations in power grid power, improve the safety of power grid equipment during operation, and improve the economy of the power grid.

[0005] In a first aspect, an embodiment of the present application provides a gravity energy storage system, which includes a plurality of lifting energy storage power generation systems and an electrochemical energy storage system, each lifting energy storage power generation system and the electrochemical energy storage system are electrically connected to an AC power grid:

[0006] Each lifting energy storage power generation system is used to release electric energy to the AC power grid for power generation, or absorb electric energy from the AC power grid for energy storage; the electrochemical energy storage system is used to absorb electric energy during power generation, or release electric energy during energy storage.

[0007] Optionally, the lifting energy storage power generation system comprises a heavy object lifting device and an energy storage power generation device;

[0008] The energy storage and power generation device is used to release electric energy to the heavy object lifting device; the heavy object lifting device is used to transport the heavy object from a low position to a high position under the action of electric energy, and convert the electric energy into potential energy to realize energy storage;

[0009] The heavy object lifting device is used to transport the heavy object from a high position to a low position, and convert potential energy into kinetic energy; the energy storage and power generation device is used to generate electrical energy and release the electrical energy to the AC power grid to achieve power generation.

[0010] Optionally, the heavy object lifting device comprises a heavy object cabin and a transmission wheel, and the heavy object cabin is connected to the transmission wheel via a shaft system;

[0011] The heavy object compartment is used for placing the heavy objects; the transmission wheel is used for rotating under the action of electric energy to drive the heavy object compartment to move.

[0012] Optionally, the energy storage power generation device includes a motor, a frequency converter and a DC transformer, the motor is connected to the frequency converter via three-phase AC power, and the frequency converter is connected to the DC transformer via positive and negative DC power;

[0013] The DC transformer is used to absorb electric energy from the AC power grid and drive the motor to operate through the frequency converter; the motor is used to drive the heavy object lifting device to operate and transport the heavy object from a low position to a high position;

[0014] The motor is used to generate electric energy when the heavy object lifting device transports the heavy object from a high position to a low position, and release the electric energy to the DC transformer through the frequency converter; the DC transformer is used to release the electric energy to the AC power grid.

[0015] Optionally, the gravity energy storage system further includes a DC bus; the DC bus is used to connect each lifting energy storage power generation system, the AC power grid and the electrochemical energy storage system.

[0016] Optionally, the gravity energy storage system further includes a grid-connected inverter and a first transformer, the grid-connected inverter is connected to each lifting energy storage power generation system through the DC bus, and the grid-connected inverter is connected to the AC power grid through the first transformer;

[0017] The DC bus is used to collect the electric energy released by each lifting energy storage power generation system and transmit it to the grid-connected inverter; the grid-connected inverter is used to convert the received electric energy into AC power; the first transformer is used to connect the AC power grid to the grid.

[0018] Optionally, the system further includes a second transformer, which is connected to each lifting energy storage power generation system and the electrochemical energy storage system through the DC bus; the second transformer is used to convert the voltage of the electric energy released by the electrochemical energy storage system.

[0019] In a second aspect, an embodiment of the present application provides a gravity energy storage method, which is applied to a gravity energy storage system, wherein the gravity energy storage system includes a plurality of lifting energy storage power generation systems and an electrochemical energy storage system, wherein each lifting energy storage power generation system and the electrochemical energy storage system are electrically connected to each other, and the method includes:

[0020] Each lifting energy storage power generation system releases electric energy to the AC power grid to generate electricity, or absorbs electric energy from the AC power grid to store energy; the electrochemical energy storage system absorbs electric energy during the power generation process, or releases electric energy during the energy storage process.

[0021] Optionally, the lifting energy storage power generation system includes a heavy object lifting device and an energy storage power generation device, and the method includes:

[0022] The energy storage and power generation device releases electric energy to the heavy object lifting device; the heavy object lifting device transports the heavy object from a low position to a high position under the action of the electric energy, converts the electric energy into potential energy to realize energy storage;

[0023] The heavy object lifting device transports the heavy object from a high position to a low position, converting potential energy into kinetic energy; the energy storage and power generation device generates electrical energy and releases the electrical energy to the AC power grid to achieve power generation.

[0024] Optionally, the heavy object lifting device comprises a heavy object cabin and a transmission wheel, the heavy object cabin is connected to the transmission wheel via a shaft system, and the method comprises:

[0025] The heavy object is placed in the heavy object compartment; the transmission wheel rotates under the action of electric energy to drive the heavy object compartment to move.

[0026] Optionally, the energy storage power generation device includes a motor, a frequency converter and a DC transformer, the motor is connected to the frequency converter via three-phase AC power, the frequency converter is connected to the DC transformer via positive and negative DC power, and the method includes:

[0027] The DC transformer absorbs electric energy from the AC power grid and drives the motor to operate through the frequency converter; the motor drives the heavy object lifting device to operate and transport the heavy object from a low position to a high position;

[0028] The motor generates electric energy when the heavy object lifting device transports the heavy object from a high position to a low position, and releases the electric energy to the DC transformer through the frequency converter; the DC transformer releases the electric energy to the AC power grid.

[0029] Optionally, the gravity energy storage system further includes a DC bus, and the method includes:

[0030] The DC bus connects each lifting energy storage power generation system, the AC power grid and the electrochemical energy storage system.

[0031] Optionally, the gravity energy storage system further includes a grid-connected inverter and a first transformer, the grid-connected inverter is connected to each lifting energy storage power generation system through the DC bus, and the grid-connected inverter is connected to the AC power grid through the first transformer, and the method includes:

[0032] The DC bus collects the electric energy released by each lifting energy storage power generation system and transmits it to the grid-connected inverter; the grid-connected inverter converts the received electric energy into AC power; and the first transformer connects the AC power grid to the grid.

[0033] Optionally, the system further includes a second transformer, and the second transformer is connected to each lifting energy storage power generation system and the electrochemical energy storage system through the DC bus. The method includes:

[0034] The second transformer performs voltage conversion on the electric energy released by the electrochemical energy storage system.

[0035] In a third aspect, an embodiment of the present application provides a computer device, comprising: a processor, a memory and a bus, wherein the memory stores machine-readable instructions executable by the processor, and when the computer device is running, the processor and the memory communicate through the bus, and when the machine-readable instructions are executed by the processor, the steps of the gravity energy storage method described in any optional implementation manner of the second aspect are performed.

[0036] In a fourth aspect, an embodiment of the present application provides a computer-readable storage medium having a computer program stored thereon, and when the computer program is executed by a processor, the steps of the gravity energy storage method described in any optional implementation manner in the second aspect above are executed.

[0037] The technical solution provided by this application includes but is not limited to the following beneficial effects:

[0038] The gravity energy storage system provided in the present application introduces an electrochemical energy storage system. In the non-generation or non-energy storage stage of the lifting energy storage power generation system, such as the empty load compartment rising and falling and the heavy objects waiting to be transported, the electrochemical energy storage system can respond quickly and absorb or release electric energy quickly. This feature effectively makes up for the lack of electric power or power generation power of the crane in these stages, thereby avoiding power fluctuations in the grid caused by frequent power changes. This suppression of power fluctuations helps to maintain the electric power of the grid at a relatively stable value, reduces the load fluctuations of the grid, and improves the overall stability of the grid, thereby improving the safety of grid equipment during operation and the economy of the grid.

[0039] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0041] Figure 1 A schematic diagram of a gravity energy storage system provided by Embodiment 1 of the present invention is shown;

[0042] Figure 2 A schematic diagram of a second gravity energy storage system provided by the first embodiment of the present invention is shown;

[0043] Figure 3 A schematic diagram of a third gravity energy storage system provided by the first embodiment of the present invention is shown;

[0044] Figure 4 A schematic diagram of a fourth gravity energy storage system provided by the first embodiment of the present invention is shown;

[0045] Figure 5 A power timing diagram of a gravity energy storage system provided by the first embodiment of the present invention during the energy storage process is shown;

[0046] Figure 6 A power timing diagram of a gravity energy storage system provided by the first embodiment of the present invention during power generation is shown;

[0047] Figure 7 A schematic diagram of a fifth gravity energy storage system provided by the first embodiment of the present invention is shown;

[0048] Figure 8A schematic diagram of a sixth gravity energy storage system provided by the first embodiment of the present invention is shown;

[0049] Fig. 9 A schematic diagram of a seventh gravity energy storage system provided by the first embodiment of the present invention is shown;

[0050] Fig.10 A schematic diagram of an eighth gravity energy storage system provided by the first embodiment of the present invention is shown;

[0051] Fig.11 A schematic diagram of the structure of a computer device provided in Embodiment 3 of the present invention is shown. DETAILED DESCRIPTION

[0052] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. The components of the embodiments of the present invention generally described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative work belong to the scope of protection of the present invention.

[0053] Embodiment 1

[0054] To facilitate understanding of this application, Figure 1 The schematic diagram of a gravity energy storage system provided by the first embodiment of the present invention is shown to describe the contents of the first embodiment of the present application in detail.

[0055] See also Figure 1 As shown, Figure 1 A schematic diagram of a gravity energy storage system provided in Embodiment 1 of the present invention is shown, wherein the gravity energy storage system includes a plurality of lifting energy storage power generation systems 10 and an electrochemical energy storage system 20, and each lifting energy storage power generation system and the electrochemical energy storage system are electrically connected to an AC power grid.

[0056] Specifically, each lifting energy storage and power generation system is connected to the electrochemical energy storage system and the AC power grid through electrical connections. These connections allow the lifting energy storage and power generation system to exchange electrical energy with the power grid and other energy storage systems during energy storage and power generation.

[0057] Each lifting energy storage power generation system is used to release electric energy to the AC power grid for power generation, or absorb electric energy from the AC power grid for energy storage; the electrochemical energy storage system is used to absorb electric energy during the power generation process, or release electric energy during the energy storage process.

[0058] Specifically, each lifting energy storage power generation system is the core part of the gravity energy storage system. They store and release electrical energy by lifting and lowering heavy objects. Specifically, when the system is in energy storage mode, the lifting energy storage power generation system absorbs electrical energy from the AC power grid, uses this electrical energy to drive the crane to lift the heavy objects to the top of the building, thereby converting the electrical energy into the gravitational potential energy of the heavy objects. On the contrary, in power generation mode, the lifting energy storage power generation system releases the heavy objects, uses the gravitational potential energy of the heavy objects to drive the crane to generate electricity, and feeds the generated electrical energy back to the AC power grid.

[0059] The electrochemical energy storage system plays an important role in the gravity energy storage system. Its main function is to provide electrical energy support when the power of the lifting energy storage power generation system fluctuates to ensure the stability of the power grid. Specifically, during the energy storage process, when the lifting energy storage power generation system is suspended (such as when heavy objects are waiting to be transported to the top or bottom floor of a building), the electrochemical energy storage system will release electrical energy to make up for the power gap in the grid. During the power generation process, when the lifting energy storage power generation system is also suspended, the electrochemical energy storage system will absorb excess electrical energy to prevent excess power in the grid.

[0060] In an alternative embodiment, see Figure 2 As shown, Figure 2 A schematic diagram of a second gravity energy storage system provided in the first embodiment of the present invention is shown, wherein the lifting energy storage power generation system 10 comprises a heavy object lifting device 101 and an energy storage power generation device 102;

[0061] The energy storage and power generation device is used to release electric energy to the heavy object lifting device; the heavy object lifting device is used to transport heavy objects from a low position to a high position under the action of electric energy, and convert the electric energy into potential energy to realize energy storage.

[0062] Specifically, the heavy object lifting device is responsible for the vertical transportation of heavy objects. During the energy storage process, the energy storage power generation device operates as an electric device, absorbs electrical energy from the power grid, and drives the heavy object lifting device through the transmission wheel to lift the heavy object to a high position. The heavy object lifting device transports heavy objects from a low position (such as the bottom floor of a building) to a high position (such as the top floor of a building). In this process, electrical energy is converted into the gravitational potential energy of the heavy object, realizing energy storage.

[0063] The heavy object lifting device is used to transport the heavy object from a high position to a low position, and convert potential energy into kinetic energy; the energy storage and power generation device is used to generate electrical energy and release the electrical energy to the AC power grid to achieve power generation.

[0064] Specifically, during the power generation process, the heavy object is lowered from a high position to a low position through a heavy object lifting device, and the gravitational potential energy of the heavy object is used to drive the power generation device in the energy storage power generation device to generate electricity. The generated electric energy is converted into alternating current suitable for grid access through power electronic equipment (such as frequency converter, DC transformer, grid-connected inverter).

[0065] In an alternative embodiment, see Figure 3 As shown, Figure 3 A schematic diagram of a third gravity energy storage system provided in Embodiment 1 of the present invention is shown, wherein the weight lifting device 101 includes a weight cabin 1011 and a transmission wheel 1012, and the weight cabin is connected to the transmission wheel through an axis system; the weight cabin is used to place the weight; and the transmission wheel is used to rotate under the action of electric energy to drive the weight cabin to move.

[0066] Specifically, the weight cabin is the part of the lifting device used to place heavy objects. During the energy storage process, the weight cabin will load the heavy objects and descend to the bottom layer; while during the power generation process, the weight cabin will carry the heavy objects up to the top layer. By lifting and lowering the heavy objects, the weight cabin realizes the conversion between gravitational potential energy and electrical energy.

[0067] The transmission wheel is a power transmission component in the lifting device. It converts electrical energy into mechanical energy through connection with the shaft system, thereby driving the movement of the weight compartment. During the energy storage process, the transmission wheel rotates counterclockwise (in a certain direction as an example) driven by the electrical energy, driving the weight compartment to descend; while during the power generation process, the transmission wheel will rotate clockwise (in the opposite direction of the energy storage process as an example) under the action of the gravity of the weight, and then transmit the mechanical energy to the motor through the shaft system and convert it into electrical energy output.

[0068] In an alternative embodiment, see Figure 4 As shown, Figure 4 A schematic diagram of a fourth gravity energy storage system provided in Embodiment 1 of the present invention is shown, wherein the energy storage power generation device 102 includes a motor 1021, a frequency converter 1022 and a DC transformer 1023, the motor is connected to the frequency converter via three-phase AC power, and the frequency converter is connected to the DC transformer via positive and negative DC power.

[0069] The DC transformer is used to absorb electric energy from the AC power grid and drive the motor to operate through the frequency converter; the motor is used to drive the heavy object lifting device to operate and transport the heavy object from a low position to a high position.

[0070] Specifically, when the system is in energy storage mode, the DC transformer first absorbs electrical energy from the AC grid. This electrical energy is then converted into three-phase AC power suitable for motor operation through the inverter. The inverter acts as a motor controller and adjusts the speed and power of the motor according to preset instructions or algorithms. The motor runs under the drive of the inverter, which in turn drives the weight lifting device. In this process, the motor converts electrical energy into mechanical energy, which is used to transport heavy objects from a low position (such as the bottom floor of a building) to a high position (such as the top floor of a building).

[0071] For further information, see Figure 5 As shown, Figure 5 A timing diagram of the power of a gravity energy storage system provided in the first embodiment of the present invention during the energy storage process is shown, wherein during the energy storage operation of the gravity energy storage system, the motor power is the rated power P0, and the power generation power of the electrochemical energy storage system is P2, at which time the DC grid power = the rated electric power of the motor P0 - the power generation power P2 of the electrochemical energy storage system. During the process of releasing the heavy object, the process of the empty lowering of the heavy object cabin, and the process of picking up the heavy object, the motor power is 0, that is, the power is zero. The charging power of the electrochemical energy storage system is P1, at which time the DC grid power = 0 + the charging power P1 of the electrochemical energy storage system.

[0072] In order to make the power consumption of the power grid a stable value, P1=P0-P2.

[0073] In order to balance the charging and discharging of the chemical energy storage system within the full time scale of power, P1*T1=P2*T2, where T1 is the charging time during the energy storage process and T2 is the discharging time during the energy storage process.

[0074] During the energy storage operation, when the charging and discharging power of the electrochemical energy storage system satisfies the above relationship, the electric power of the power grid can be maintained at a stable value, thereby eliminating the problem of power fluctuations in the power grid.

[0075] The motor is used to generate electric energy when the heavy object lifting device transports the heavy object from a high position to a low position, and release the electric energy to the DC transformer through the frequency converter; the DC transformer is used to release the electric energy to the AC power grid.

[0076] Specifically, when the system is in power generation mode, the working mode of the motor is reversed. At this time, the weight falls from a high position to a low position under the action of its own gravity, driving the motor to rotate. The motor generates electrical energy during rotation, which is also converted by the inverter. However, this time the mechanical energy is converted into electrical energy and output in the form of three-phase AC. The electrical energy output by the inverter is then fed into a DC transformer. The DC transformer is responsible for converting this AC into DC and further adjusting the voltage level to make it suitable for release to the AC power grid. After conversion and adjustment by the DC transformer, the electrical energy is fed into the AC power grid. This process realizes the release of electrical energy from the gravity energy storage system to the power grid, providing a stable and reliable power supply to the power grid.

[0077] For further information, see Figure 6 As shown, Figure 6 A timing diagram of the power of a gravity energy storage system provided in the first embodiment of the present invention during power generation is shown, wherein during the power generation operation of the gravity energy storage system, the motor power is the rated power P10, and the charging power of the electrochemical energy storage system is P12, and the grid-connected power = rated power P10 - the charging power P12 of the electrochemical energy storage system. During the process of releasing heavy objects, the process of the empty lifting of the heavy object cabin, and the process of picking up heavy objects, the power generated by the motor is 0, that is, the power is zero. The power generated by the electrochemical energy storage system is P11, and at this time the DC grid power = 0 + the charging power of the electrochemical energy storage system is P11.

[0078] In order to make the generated power a stable value, P11=P10-P12.

[0079] In order to balance the charging and discharging of the chemical energy storage system within the full time scale of power, P11*T3=P12*T4, where T1 is the charging time during the power generation process and T2 is the discharging time during the power generation process.

[0080] During the power generation process, when the charging and discharging power of the electrochemical energy storage system satisfies the above relationship, the electric power of the power grid can be maintained at a stable value, thereby eliminating the problem of power generation fluctuations.

[0081] In an alternative embodiment, see Figure 7 As shown, Figure 7 A schematic diagram of a fifth gravity energy storage system provided in Embodiment 1 of the present invention is shown, wherein the gravity energy storage system further comprises a DC bus 103; the DC bus is used to connect each lifting energy storage power generation system, the AC power grid and the electrochemical energy storage system.

[0082] Specifically, each lifting energy storage power generation system is connected to the DC bus through a frequency converter and a DC transformer. In this way, both the power input during the energy storage process and the power output during the power generation process can be uniformly managed and dispatched through the DC bus. The electrochemical energy storage system is also connected to the DC bus through a DC transformer. This enables the electrochemical energy storage system to quickly absorb or release electrical energy as needed to smooth out possible power fluctuations in the system. Through the grid-connected inverter, the DC bus can convert the DC power generated by the system into AC power and send it to the AC power grid safely and stably. At the same time, when the system needs energy storage, the grid-connected inverter can also absorb power from the AC power grid, convert it into DC power, and then supply it to each lifting energy storage power generation system.

[0083] During the energy storage process, each lifting energy storage power generation system absorbs electrical energy from the AC power grid, transfers the electrical energy to the electrochemical energy storage system through the DC bus (at this time the electrochemical energy storage system is in a charging state) and is used to lift heavy objects. During the power generation process, the gravitational potential energy released by the descending heavy objects is converted into electrical energy, transferred to the electrochemical energy storage system through the DC bus (at this time the electrochemical energy storage system may be in a discharging state to smooth out power fluctuations) and finally sent to the AC power grid.

[0084] In an alternative embodiment, see Figure 8 As shown, Figure 8 A schematic diagram of the sixth gravity energy storage system provided in the first embodiment of the present invention is shown, wherein the gravity energy storage system further includes a grid-connected inverter 104 and a first transformer 105, the grid-connected inverter is connected to each lifting energy storage power generation system through the DC bus, and the grid-connected inverter is connected to the AC power grid through the first transformer.

[0085] The DC bus is used to collect the electric energy released by each lifting energy storage power generation system and transmit it to the grid-connected inverter; the grid-connected inverter is used to convert the received electric energy into AC power; the first transformer is used to connect the AC power grid to the grid.

[0086] Specifically, the grid-connected inverter is a bridge connecting the DC bus and the AC power grid. It is responsible for converting the DC power on the DC bus into AC power suitable for AC power grid access. This conversion process requires not only high quality of electric energy (such as stable voltage, sinusoidal waveform, etc.), but also high conversion efficiency to reduce energy loss. The grid-connected inverter is connected to each lifting energy storage power generation system through the DC bus. When each lifting energy storage power generation system is in the power generation state, the electric energy they release will be collected on the DC bus and then transferred to the grid-connected inverter. After receiving this electric energy, the grid-connected inverter will convert DC to AC to prepare for subsequent grid-connected operations.

[0087] One end of the first transformer is connected to the grid-connected inverter to receive the AC power output. The other end is connected to the AC power grid to send the converted power into the grid. Through the adjustment of the first transformer, the system can flexibly adapt to the grid requirements of different voltage levels. During the power generation process of the gravity energy storage system, the power released by each lifting energy storage power generation system is first collected on the DC bus. Then, the power is transmitted to the grid-connected inverter for DC to AC conversion. The converted AC power is converted into a voltage level through the first transformer, and finally safely and stably incorporated into the AC power grid.

[0088] In an alternative embodiment, see Fig. 9 As shown, Fig. 9 A schematic diagram of the seventh gravity energy storage system provided in Embodiment 1 of the present invention is shown, wherein the system further includes a second transformer 106, which is connected to each lifting energy storage power generation system and the electrochemical energy storage system through the DC bus; the second transformer is used to convert the voltage of the electric energy released by the electrochemical energy storage system.

[0089] Specifically, the second transformer is connected to each lifting and lowering energy storage power generation system and the electrochemical energy storage system through a DC bus. This means that whether the electrochemical energy storage system releases or absorbs electrical energy, it needs to undergo voltage conversion through the second transformer to adapt to the voltage level on the DC bus. One end of the second transformer is connected to the electrochemical energy storage system, and the other end is connected to the DC bus. When the electrochemical energy storage system needs to release electrical energy, the electrical energy will enter the DC bus after being stepped up (or stepped down, depending on the system design) by the second transformer; when the electrochemical energy storage system needs to absorb electrical energy, the electrical energy on the DC bus will enter the electrochemical energy storage system for charging after being stepped down (or stepped up) by the second transformer.

[0090] The second transformer in the gravity energy storage system is mainly used to convert the voltage of the electric energy released or absorbed by the electrochemical energy storage system. Since the electrochemical energy storage system (such as a battery pack) usually has a specific voltage level, and other parts of the system (such as each lifting energy storage power generation system, DC bus and grid-connected inverter) may need to work at different voltage levels, the second transformer plays a role in voltage adaptation.

[0091] In order to facilitate the understanding of this application, this application provides a complete gravity energy storage system. Fig.10 As shown, Fig.10The schematic diagram of the eighth gravity energy storage system provided by the first embodiment of the present invention is shown, wherein a heavy object placement area is respectively set on the top and bottom floors of the building, and a plurality of heavy object lifting passages are arranged on one side of the building, and a heavy object cabin is arranged in the lifting passage to be responsible for the handling of heavy objects. A transmission wheel is placed below or above the lifting passage, and the transmission wheel is mechanically connected to the motor through a shaft system, and the motor has an electric function and a power generation function. The motor is connected to the frequency converter, and the frequency converter controls the drive of the motor to realize the power generation and electric function. The frequency converter is connected to the motor through a three-phase alternating current connection. The frequency converter is connected to the DC transformer through positive and negative DC. The DC transformer realizes the conversion of low-voltage DC to medium-voltage or high-voltage DC voltage and the transmission of electric energy. In the system, a plurality of lifting energy storage power generation systems are arranged, and each lifting energy storage power generation system corresponds to a group of transmission wheels, shaft systems, motors, frequency converters and DC transformer devices. Multiple medium-voltage or high-voltage DC power is collected on the DC bus. Then, the conversion of DC to AC is realized by a grid-connected inverter, and the grid connection of electric energy is realized by a power transformer (first transformer). Another DC transformer (second transformer) is connected to the medium voltage or high voltage DC bus to achieve the conversion from medium voltage or high voltage DC to low voltage DC, and an electrochemical energy storage system is arranged to be connected to the DC transformer through the low voltage DC bus. In order to suppress the power fluctuation caused by the generation and zero generation power during the above-mentioned process of picking up heavy objects, releasing heavy objects, and the empty load rise and fall of the heavy object cabin. The electrochemical system is made to quickly release and absorb electric energy to the medium voltage or high voltage DC bus through the DC transformer to eliminate power fluctuations and maintain the grid-connected power of the centralized grid-connected inverter stable.

[0092] Embodiment 2

[0093] Embodiment 2 of the present invention provides a gravity energy storage method, which is applied to a gravity energy storage system, wherein the gravity energy storage system includes a plurality of lifting energy storage power generation systems and an electrochemical energy storage system, each lifting energy storage power generation system and the electrochemical energy storage system are electrically connected to each other, and the method includes the steps of:

[0094] Each lifting energy storage power generation system releases electric energy to the AC power grid to generate electricity, or absorbs electric energy from the AC power grid to store energy; the electrochemical energy storage system absorbs electric energy during the power generation process, or releases electric energy during the energy storage process.

[0095] In an optional embodiment, the lifting energy storage power generation system includes a heavy object lifting device and an energy storage power generation device, and the method includes:

[0096] The energy storage and power generation device releases electric energy to the heavy object lifting device; the heavy object lifting device transports the heavy object from a low position to a high position under the action of the electric energy, converts the electric energy into potential energy to realize energy storage;

[0097] The heavy object lifting device transports the heavy object from a high position to a low position, converting potential energy into kinetic energy; the energy storage and power generation device generates electrical energy and releases the electrical energy to the AC power grid to achieve power generation.

[0098] In an optional embodiment, the heavy object lifting device comprises a heavy object cabin and a transmission wheel, the heavy object cabin is connected to the transmission wheel via a shaft system, and the method comprises:

[0099] The heavy object is placed in the heavy object compartment; the transmission wheel rotates under the action of electric energy to drive the heavy object compartment to move.

[0100] In an optional embodiment, the energy storage power generation device includes a motor, a frequency converter and a DC transformer, the motor is connected to the frequency converter via three-phase AC power, the frequency converter is connected to the DC transformer via positive and negative DC power, and the method includes:

[0101] The DC transformer absorbs electric energy from the AC power grid and drives the motor to operate through the frequency converter; the motor drives the heavy object lifting device to operate and transport the heavy object from a low position to a high position;

[0102] The motor generates electric energy when the heavy object lifting device transports the heavy object from a high position to a low position, and releases the electric energy to the DC transformer through the frequency converter; the DC transformer releases the electric energy to the AC power grid.

[0103] In an optional embodiment, the gravity energy storage system further includes a DC bus, and the method includes:

[0104] The DC bus connects each lifting energy storage power generation system, the AC power grid and the electrochemical energy storage system.

[0105] In an optional embodiment, the gravity energy storage system further includes a grid-connected inverter and a first transformer, the grid-connected inverter is connected to each lifting energy storage power generation system through the DC bus, the grid-connected inverter is connected to the AC power grid through the first transformer, and the method includes:

[0106] The DC bus collects the electric energy released by each lifting energy storage power generation system and transmits it to the grid-connected inverter; the grid-connected inverter converts the received electric energy into AC power; and the first transformer connects the AC power grid to the grid.

[0107] In an optional embodiment, the system further includes a second transformer, the second transformer is connected to each lifting energy storage power generation system and the electrochemical energy storage system through the DC bus, and the method includes:

[0108] The second transformer performs voltage conversion on the electric energy released by the electrochemical energy storage system.

[0109] Embodiment 3

[0110] Based on the same application concept, see Fig.11 As shown, Fig.11 FIG. 4 shows a schematic diagram of the structure of a computer device provided by Embodiment 3 of the present invention, wherein: Fig.11 As shown, a computer device 1100 provided in Embodiment 3 of the present application includes:

[0111] A processor 1101, a memory 1102 and a bus 1103, wherein the memory 1102 stores machine-readable instructions executable by the processor 1101. When the computer device 1100 is running, the processor 1101 communicates with the memory 1102 via the bus 1103. When the processor 1101 is running, the machine-readable instructions execute the steps of the gravity energy storage method shown in the above-mentioned embodiment 2.

[0112] Embodiment 4

[0113] Based on the same application concept, an embodiment of the present application further provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps of the gravity energy storage method described in any one of the above embodiments are executed.

[0114] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working process of the system and device described above can refer to the corresponding process in the aforementioned method embodiment, and will not be repeated here.

[0115] The computer program product for gravity energy storage provided in the embodiment of the present invention includes a computer-readable storage medium storing program code. The instructions included in the program code can be used to execute the method described in the previous method embodiment. The specific implementation can be found in the method embodiment, which will not be repeated here.

[0116] The gravity energy storage system provided in the embodiment of the present invention can be specific hardware on the device or software or firmware installed on the device. The system provided in the embodiment of the present invention has the same implementation principle and technical effects as the aforementioned method embodiment. For the sake of brief description, the parts not mentioned in the system embodiment can refer to the corresponding contents in the aforementioned method embodiment. Those skilled in the art can clearly understand that for the convenience and simplicity of description, the specific working processes of the systems, devices and units described above can all refer to the corresponding processes in the aforementioned method embodiment, and will not be repeated here.

[0117] In the embodiments provided by the present invention, it should be understood that the disclosed systems and methods can be implemented in other ways. The system embodiments described above are only schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some communication interface, device or unit, which can be electrical, mechanical or other forms.

[0118] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0119] In addition, each functional unit in the embodiment provided by the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0120] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the methods described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, etc., which can store program codes.

[0121] It should be noted that similar numbers and letters represent similar items in the following figures. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description and are not to be understood as indicating or implying relative importance.

[0122] Finally, it should be noted that the above-described embodiments are only specific implementations of the present invention, which are used to illustrate the technical solutions of the present invention, rather than to limit them. The protection scope of the present invention is not limited thereto. Although the present invention is described in detail with reference to the above-described embodiments, those skilled in the art should understand that any person skilled in the art can still modify the technical solutions described in the above-described embodiments within the technical scope disclosed by the present invention, or can easily think of changes, or perform equivalent replacements on some of the technical features thereof; and these modifications, changes or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention. They should all be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A gravity energy storage system, characterized in that: The gravity energy storage system includes several lifting energy storage power generation systems and electrochemical energy storage systems, and each lifting energy storage power generation system and the electrochemical energy storage system are electrically connected to the AC power grid: Each lifting energy storage power generation system is used to release electric energy to the AC power grid for power generation, or absorb electric energy from the AC power grid for energy storage; the electrochemical energy storage system is used to absorb electric energy during power generation, or release electric energy during energy storage.

2. The gravity energy storage system according to claim 1, characterized in that: The lifting energy storage power generation system comprises a heavy object lifting device and an energy storage power generation device; The energy storage and power generation device is used to release electric energy to the heavy object lifting device; the heavy object lifting device is used to transport the heavy object from a low position to a high position under the action of electric energy, and convert the electric energy into potential energy to realize energy storage; The heavy object lifting device is used to transport the heavy object from a high position to a low position, and convert potential energy into kinetic energy; the energy storage and power generation device is used to generate electrical energy and release the electrical energy to the AC power grid to achieve power generation.

3. The gravity energy storage system according to claim 2, characterized in that: The heavy object lifting device comprises a heavy object cabin and a transmission wheel, wherein the heavy object cabin is connected to the transmission wheel via a shaft system; The heavy object compartment is used for placing the heavy objects; the transmission wheel is used for rotating under the action of electric energy to drive the heavy object compartment to move.

4. The gravity energy storage system according to claim 2, characterized in that: The energy storage power generation device comprises a motor, a frequency converter and a DC transformer, wherein the motor is connected to the frequency converter via three-phase AC power, and the frequency converter is connected to the DC transformer via positive and negative DC power; The DC transformer is used to absorb electric energy from the AC power grid and drive the motor to operate through the frequency converter; the motor is used to drive the heavy object lifting device to operate and transport the heavy object from a low position to a high position; The motor is used to generate electric energy when the heavy object lifting device transports the heavy object from a high position to a low position, and release the electric energy to the DC transformer through the frequency converter; the DC transformer is used to release the electric energy to the AC power grid.

5. The gravity energy storage system according to claim 1, characterized in that: The gravity energy storage system also includes a DC bus; the DC bus is used to connect each lifting energy storage power generation system, the AC power grid and the electrochemical energy storage system.

6. The gravity energy storage system according to claim 5, characterized in that: The gravity energy storage system further includes a grid-connected inverter and a first transformer, wherein the grid-connected inverter is connected to each lifting energy storage power generation system via the DC bus, and the grid-connected inverter is connected to the AC power grid via the first transformer; The DC bus is used to collect the electric energy released by each lifting energy storage power generation system and transmit it to the grid-connected inverter; The grid-connected inverter is used to convert the electric energy it receives into direct current into alternating current; The first transformer is used for connecting electric energy to the AC power grid.

7. The gravity energy storage system according to claim 5, characterized in that: The system also includes a second transformer, which is connected to each lifting energy storage power generation system and the electrochemical energy storage system through the DC bus; the second transformer is used to convert the voltage of the electric energy released by the electrochemical energy storage system.

8. A gravity energy storage method, characterized in that: Applied to a gravity energy storage system, the gravity energy storage system includes a plurality of lifting energy storage power generation systems and an electrochemical energy storage system, each lifting energy storage power generation system and the electrochemical energy storage system are electrically connected to each other, the method includes: Each lifting energy storage power generation system releases electric energy to the AC power grid to generate electricity, or absorbs electric energy from the AC power grid to store energy; the electrochemical energy storage system absorbs electric energy during the power generation process, or releases electric energy during the energy storage process.

9. A computer device, characterized in that: include: A processor, a memory and a bus, wherein the memory stores machine-readable instructions executable by the processor, and when the computer device is running, the processor and the memory communicate via the bus, and when the machine-readable instructions are executed by the processor, the steps of the gravity energy storage method as described in claim 8 are performed.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the gravity energy storage method as claimed in claim 8 are executed.

Images