An energy storage power generation system

Abstract

The application provides a kind of energy storage power generation system.The energy storage power generation system includes upper reservoir and lower reservoir, waterway system and first signal, motor set and circuit conversion device, excitation device and second signal, speed regulation structure and third signal, and intelligent device.The lower reservoir is arranged in the mine tunnel of mine, the circuit conversion device is connected to external power grid, the motor set is connected to the circuit conversion device, the motor set is used to consume the electric energy of the circuit conversion device to pump the water flow by pump wheel in the first working condition, and the motor set is used to send the electric energy to the circuit conversion device by pump wheel driven by water flow in the second working condition.The excitation device is used to excite the magnetic field with adjustable magnetic field strength in the motor set, the speed regulation structure is used to control the opening of movable guide vane, the intelligent device includes processor, the intelligent device is used to receive first electric signal, second electric signal and third electric signal, and analyze by processor to instruct excitation device to adjust the magnetic field strength of motor set, instruct speed regulation structure to adjust the water flow of motor set.

Description

Technical Field

[0001] This application relates to the field of energy technology, and in particular to an energy storage power generation system. Background Technology

[0002] This section is intended to provide background or context for the implementation of this application. The description herein is not intended to imply that it is prior art simply because it is included in this section.

[0003] In the context of rapid development of new energy technologies, pumped-storage power stations play a crucial role in promoting the consumption of new energy sources, providing key and reliable support for ensuring the safe and stable operation of the power grid and promoting the green and low-carbon transformation of energy. Given the vast underground space resources of coal mines, the future conversion of closed mines into water, gas, and oil storage facilities holds great promise. However, current pumped-storage power station projects in mining areas still face challenges such as large construction workloads, high construction difficulty, and low economic benefits. Summary of the Invention

[0004] In view of this, the embodiments of this application aim to provide an energy storage power generation system with a relatively simple topology design, which is easy to implement and has high operating efficiency.

[0005] This application provides an energy storage and power generation system for use in mines, including: An upper reservoir and a lower reservoir, wherein the upper reservoir is located above the lower reservoir and the lower reservoir is located inside the mine shaft; A waterway system and a first signal device, wherein the waterway system connects the upper reservoir and the lower reservoir, and the first signal device is used to measure the head information of the waterway system and generate a first electrical signal; The system includes a motor unit and a circuit conversion device. The circuit conversion device is connected to an external power grid. The motor unit is located on the flow path of the water system and is connected to the circuit conversion device. The motor unit is used to consume the electrical energy of the circuit conversion device to pump water flow under a first operating condition, and to drive the pump wheel to send electrical energy to the circuit conversion device under a second operating condition. An excitation device and a second signal device are provided. The excitation device is connected to the motor set and is used to generate an adjustable magnetic field within the motor set. The second signal device is used to measure the magnetic field strength information of the motor set and generate a second electrical signal. The motor unit has a speed regulating structure and a third signal device. The motor unit has movable guide vanes, which are used to regulate the water flow rate through the motor unit. The speed regulating structure is used to control the opening degree of the movable guide vanes. The third signal device is used to measure the rotational speed information of the motor unit and generate a third electrical signal. The intelligent connection device is electrically connected to the excitation device and the speed regulation structure. The intelligent connection device includes a processor. The intelligent connection device is used to receive the first electrical signal, the second electrical signal and the third electrical signal, and the processor analyzes them to instruct the excitation device to adjust the magnetic field strength of the motor set and instruct the speed regulation structure to adjust the water flow rate through the motor set, respectively.

[0006] In some embodiments, the energy storage power generation system further includes a monitoring node electrically connected to the smart device. The monitoring node includes a human-machine interface component for receiving external commands, and the monitoring node is used to receive external commands and instruct the smart device.

[0007] In some embodiments, the monitoring node is electrically connected to the excitation device and the speed regulation structure, respectively, for monitoring the current status of the excitation device and the speed regulation structure.

[0008] In some embodiments, the energy storage power generation system includes a fourth signaler for measuring the AC voltage of the circuit conversion device and generating a fourth electrical signal. The smart device has a Parker transformation calculation module for receiving the fourth electrical signal and parsing the fourth electrical signal through the Parker transformation calculation module to instruct the excitation device.

[0009] In some embodiments, the circuit conversion device is connected to the stator of the motor set, the excitation device is an AC excitation system and is connected to the rotor of the motor set, and the excitation device includes a frequency converter component, which is used at least for enabling the motor set to start automatically under a first operating condition.

[0010] In some embodiments, the excitation device is also used to achieve electrical braking of the motor unit under a first operating condition.

[0011] In some embodiments, the energy storage power generation system further includes a relay protection device, which is connected to the circuit switching device, the motor unit, and the excitation device respectively. The relay protection device is used to monitor the three components and disconnect them when any of the three components malfunctions.

[0012] In some embodiments, the mine includes a shaft and at least one tunnel, the at least one tunnel being laterally connected to the shaft, the shaft forming at least a portion of the waterway system, and the motor unit being disposed within the portion of the waterway system corresponding to the shaft.

[0013] In some embodiments, the waterway system has a first opening corresponding to the portion of the well shaft, the first opening being laterally connected to the lower reservoir, the first opening being located downstream of the motor unit in a second operating condition, the pump impeller of the motor unit being positioned below the first opening, and the motor unit being located at the bottom of the well shaft.

[0014] In some embodiments, the waterway system includes a water conveyance section and a well section arranged along the water flow direction. The water conveyance section is located on the ground, and the well section is located inside the well. The well section includes an inner sleeve and an outer sleeve that are nested together. One end of the inner sleeve is connected to the water conveyance section, and the other end is connected to the outer sleeve. The outer sleeve is connected to the first opening. The motor unit is located at one end of the well section away from the water conveyance section. The motor unit includes a first channel port and a second channel port for water inlet and outlet. The first channel port is located in the inner sleeve, and the second channel port is located in the empty area between the outer sleeve and the inner sleeve.

[0015] The energy storage power generation system provided in this application embodiment is divided into relatively independent nodes such as motor units, circuit conversion devices, excitation devices, and speed regulation structures. Each node has a specialized function, and the excitation device and speed regulation structure are centrally controlled through intelligent interconnection devices. On the one hand, this reduces the number of control devices required, and on the other hand, it can accept multi-dimensional signal data. The excitation device can be linked with the speed regulation structure, making adjustment decisions more precise, reducing overshoot and lag, adapting to complex operating conditions, and enabling the energy storage power generation system to work in the best possible state, thereby improving operating efficiency. Attached Figure Description

[0016] Figure 1 This is a topology diagram of an energy storage power generation system in one embodiment of this application; Figure 2 for Figure 1 A schematic diagram of the intelligent connected device in the embodiment; Figure 3 for Figure 2 Internal diagram of the structure; Figure 4 for Figure 1 Topology diagram of the smart device in the embodiment; Figure 5 This is a schematic diagram of an energy storage power generation system in one embodiment of this application; Figure 6 for Figure 5 A magnified view of point A; Figure 7 for Figure 6 A magnified diagram of point B.

[0017] Explanation of reference numerals in the attached figures 10. Upper reservoir; 20. Lower reservoir; 30. Waterway system; 30a. First opening; 31. Water conveyance section; 32. Well section; 321. Inner casing; 322. Outer casing; 40. Motor unit; 40a. First channel opening; 40b. Second channel opening; 50. Cable; 60. Pressure regulating well; 70. Circuit conversion device; 80. Excitation device; 90. Speed ​​regulation structure; 100. Intelligent connection device; 101. Processor; 102. Power module; 103. Display module; 200. Monitoring node; 300. Relay protection device. Detailed Implementation

[0018] The embodiments of this application will be described in further detail below with reference to the accompanying drawings and examples. The following examples are used to illustrate this application, but should not be used to limit the scope of this application.

[0019] In the description of the embodiments of this application, it should be noted that the terms "vertical," "horizontal," "upper," "lower," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application. In addition, the terms "first," "second," "third," and "fourth" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0020] In the description of the embodiments of this application, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this application based on the specific circumstances.

[0021] In the embodiments of this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature and the second feature are in direct contact, or that the first feature and the second feature are in indirect contact through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0022] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example that is included in at least one embodiment or example of the embodiments of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example.

[0023] This application provides an energy storage and power generation system for use in mines. From an application perspective, China lacks experience and feasible solutions for mine-based power generation conversion. Over the past few decades, China has extensively exploited mineral resources, resulting in numerous mining areas. According to relevant research data, by the end of 2023, the number of coal mines in my country had decreased to approximately 4,300, and it is projected that by 2030, the number of closed coal mines will reach over 15,000. Given the vast underground space resources of coal mines, converting closed mines into energy storage and power generation systems is a highly innovative and promising design.

[0024] The researchers in this application noted that pumped-storage power stations in related technologies involve a large number of devices, complex topologies, and relatively dispersed layouts, resulting in significant space requirements, substantial engineering work, high construction costs, and high costs for the control devices required for each device. This is detrimental to implementing the concept of sustainable development for mine reuse.

[0025] In view of this, this application provides an energy storage power generation system. Please refer to [link to relevant documentation]. Figure 5 It includes an upper reservoir 10, a lower reservoir 20, and a waterway system 30. The upper reservoir 10 is located above the lower reservoir 20, which is located inside the mine shaft. That is, the lower reservoir 20 is based on an existing mine shaft (such as...). Figure 5 The structural foundation (pointed to by the middle arrow Q) is constructed, while the upper reservoir 10 can be built based on an existing mine at a higher location, or it can be excavated on the ground.

[0026] It should be noted that the term "mine tunnel" as used in this specification refers to an underground passage or working space used in mining operations to extract coal seams, typically extending along the direction of the ore vein. Mine tunnels include, but are not limited to, temporary roadways during excavation, working face access for coal mining, roadways connecting different areas, and chambers for storing equipment.

[0027] The waterway system 30 connects the upper reservoir 10 and the lower reservoir 20. Since the upper reservoir 10 and the lower reservoir 20 can naturally form a height difference, when the waterway system 30 is open, the water in the upper reservoir 10 flows into the lower reservoir 20 under the influence of its own weight. Thus, the water flow has a certain kinetic energy and pressure energy.

[0028] Please see Figure 1The energy storage power generation system also includes a generator set 40, a circuit conversion device 70, an excitation device 80, and a speed regulation structure 90. The circuit conversion device 70 is connected to the external power grid, and the generator set 40 is located on the flow path of the water system 30, connected to the circuit conversion device 70. The circuit conversion device 70 includes a high-voltage transformer station and switching circuits, and can be installed underground or above ground, connected via a cable 50 (e.g., Figure 2 (As shown) is connected to the motor set 40. The circuit switching device 70 can switch the motor set 40 between the first operating condition and the second operating condition.

[0029] The generator set 40 is a key component of pumped-storage power generation. In the first operating condition, the generator set 40 consumes the electrical energy of the circuit conversion device 70 to pump water, and in the second operating condition, it is driven by the water flow to send electrical energy to the circuit conversion device 70. In other words, the generator set 40 can consume the energy of the grid to pump water, and it can also convert the energy of the falling water flow to generate electricity for the grid. Thus, it utilizes the characteristics of pumped-storage energy to play a role in "peak shaving and valley filling" for the power grid.

[0030] It is understandable that the motor unit 40 is a reversible motor, with the pump impeller and motor windings assembled together, or in other words, the power output shaft of the motor unit 40 is mechanically connected to the shaft of the pump impeller. The circuit conversion device 70 allows the stator or rotor windings of the motor to operate under different wiring configurations, thus enabling the pump impeller to function as both a pump and a turbine, achieving structural reuse and reducing the number of devices. During construction, the amount of work involved in hoisting the motor unit 40 is also relatively small; for example, the motor unit 40 can be directly installed in the mine shaft (e.g.,...). Figure 5 Inside (pointed to by the middle arrow P).

[0031] As an optional embodiment, the motor unit 40 is designed for a high speed of 750 r / min.

[0032] The excitation device 80 is connected to the generator set 40, and is used to generate an adjustable magnetic field within the generator set 40. It can be understood that the excitation device 80 directly affects the driving power and power generation of the generator set 40. The aforementioned adjustable magnetic field strength means that the magnetic field strength can be controlled by controlling quantifiable physical quantities such as the amplitude of the excitation current.

[0033] For example, the excitation device 80 is connected to the rotor of the motor set 40. In the first operating condition, the stator is powered by the circuit conversion device 70 to generate an alternating magnetic field. Under the action of the excitation device 80, the rotor can generate a constant magnetic field, so the rotor is pulled by the alternating magnetic field of the stator to rotate. In the second operating condition, an alternating magnetic field can be generated in the rotor. The relative motion of the stator cuts the magnetic field lines to generate an induced electromotive force, and the stator outputs electrical energy to the circuit conversion device 70.

[0034] The motor unit 40 has movable guide vanes, which are used to regulate the water flow rate of the motor unit 40. It can be understood that the movable guide vanes function similarly to valves, adjusting their opening size via electromagnetic or hydraulic drive to control the water flow rate. The speed regulating structure 90 is used to control the opening of the movable guide vanes. It should be noted that the speed regulating structure 90 is an electrical structure that converts electrical signals into executable drive signals. Under the second operating condition, the water flow rate affects the pump impeller's speed and torque, among other state parameters.

[0035] The energy storage and power generation system provided in this application also includes a first signaler, a second signaler, and a third signaler. The signalers mentioned in this specification (including the fourth signaler described below) are not limited to sensors; any device capable of measuring required information and emitting a signal using its characteristics can fall within the scope of a signaler. For example, in some embodiments, the signaler can be an induction coil or a rheostat. The signals emitted by the signalers can be analog or digital signals, serving the purpose of information transmission.

[0036] The first signal device is used to measure the head information of the waterway system 30 and generate a first electrical signal. The first signal device can be a water pressure sensor or a water level sensor, etc., and the head information indirectly reflects the kinetic energy and pressure energy of the water flow, affecting the pumpable water volume under the first working condition and the power generation under the second working condition.

[0037] The second signal device is used to measure the magnetic field strength information of the motor unit 40 and generate a second electrical signal. The second signal device can be a Hall sensor or a current sensor, etc. The second electrical signal can be direct magnetic field strength data, or it can be other physical quantity data that has a predetermined mathematical relationship with the magnetic field strength, such as the magnitude of the excitation current or parameters of each phase.

[0038] The third signal device is used to measure the rotational state information of the motor set 40 and generate a third electrical signal. The third signal device can be a photoelectric encoder or a torque sensor, etc. The aforementioned rotational state information of the motor set 40 includes, but is not limited to, the rotor speed and the rotor torque.

[0039] The energy storage power generation system of this application embodiment also includes a smart device 100, which is electrically connected to a circuit conversion device 70, an excitation device 80 and a speed regulation structure 90. The smart device 100 is used to receive a first electrical signal, a second electrical signal and a third electrical signal.

[0040] It should be noted that, Figure 1 The diagram shown is merely a topology diagram of the energy storage power generation device in this embodiment of the application, and does not limit its specific physical connection method or signal transmission method. Figure 1Three slashes on a connector line indicate that there are three wires connected here, while two slashes indicate that there are two wires connected here. For example, signal transmission can be carried out through physical connections such as cables or optical fibers, or it can be transmitted wirelessly using radio frequency signals (including but not limited to technologies such as Bluetooth, Wi-Fi, and 4G).

[0041] Please see Figure 4 The intelligent device 100 includes a processor 101. After receiving the first electrical signal, the second electrical signal and the third electrical signal, the intelligent device 100 analyzes them and instructs the excitation device 80 to adjust the magnetic field strength of the motor group 40 and instructs the speed regulation structure 90 to adjust the water flow rate through the motor group 40.

[0042] The aforementioned command excitation device 80 regulating the magnetic field strength of the motor unit 40 refers to the commanded magnetic field strength changing closer to the target value. Specifically, this can be achieved by adjusting the effective value of the excitation current or the frequency of the excitation current in the excitation device 80.

[0043] The aforementioned command speed control structure 90 regulates the water flow through the motor unit 40 by controlling the opening of the movable guide vanes and adjusting the flow rate to bring the rotational state information of the motor unit 40 closer to its current value. Specifically, this is achieved by adjusting the opening of the movable guide vanes, thereby changing the motion state of the pump impeller driven by the water flow.

[0044] The intelligent device 100 analyzes the received signals and determines the current operating state of the energy storage and power generation system. Through the processor 101 and its loaded programs or algorithms, it calculates the deviation between the current operating state and the optimal operating state, deduces the target values ​​for each signal, and generates commands to change the operating states of the circuit switching device 70, the excitation device 80, and the speed regulation structure 90 toward the target values. This process requires no manual intervention and can be executed automatically by programs or algorithms.

[0045] The optimal operating state can be parameters pre-written into the smart device 100, or it can be a prediction of the optimal operating state based on previous signal data after a machine learning algorithm model is deployed in the smart device 100. The processor 101 can refer to the central processing unit 101 in a computer, or it can refer to the microprocessor 101 in a PLC (Programmable Logic Controller).

[0046] Specifically, in some embodiments, such as Figure 4As shown, the intelligent connected device 100 consists of a processor module 101, an artificial intelligence module, a DI (Digital Input) module, a DO (Digital Output) module, an AI (Analog Input) module, an AO (Analog Output) module, a power supply module 102, a network module, and a display module 103. The DI, DO, AI, and AO modules communicate with various signal transceivers; the network module communicates with the external environment; the processor module 101 performs computational tasks; and the artificial intelligence module, specifically responsible for machine learning prediction and decision-making, can be integrated into the processor module 101. The overall structural design of the intelligent connected device 100 is as follows: Figure 3 The display module 103 is embedded in the front panel, with handles on both sides. The housing is designed with ventilation holes that have electromagnetic compatibility characteristics. Its internal layout is as follows: Figure 4 As shown.

[0047] For example, in the first operating condition, the intelligent device 100 can determine the water levels of the upper reservoir 10 and the lower reservoir 20 based on the first electrical signal, determine the required pumping speed, and instruct the excitation device 80 and the speed regulating structure 90 to control the pump impeller at an optimal speed and the movable guide vanes at an optimal opening, so that the pumping speed is close to the target value. In the second operating condition, the intelligent device 100 can match the motor unit 40 to an optimal torque speed and optimal magnetic field strength based on the head information, thereby achieving efficient power generation. Of course, the adjustment method of the intelligent device 100 is not limited to the above; it can be written into the designed program or algorithm to achieve a wider range of control effects.

[0048] In summary, the embodiments of this application provide an energy storage power generation system, which divides the system into relatively independent nodes such as the motor unit 40, circuit conversion device 70, excitation device 80, and speed regulation structure 90. Each node has a specialized function, and the excitation device 80 and speed regulation structure 90 are centrally controlled through the intelligent interconnection device 100. This reduces the number of control devices required and allows for the acceptance of multi-dimensional signal data. The excitation device 80 can be linked with the speed regulation structure 90, resulting in more precise adjustment decisions, reduced overshoot and lag, and adaptation to complex operating conditions. This enables the energy storage power generation system to operate in an optimal state and improves operating efficiency.

[0049] In some embodiments, please refer to Figure 1 The energy storage and power generation system also includes a monitoring node 200, which is electrically connected to the intelligent device 100. The monitoring node 200 includes a human-machine interface component for receiving external commands, and is used to command the intelligent device 100. The aforementioned human-machine interface component can be a control panel, a mouse, keyboard, or other human-machine interface devices.

[0050] In other words, in this embodiment, the intelligent device 100 can not only receive the first, second, and third electrical signals for feedback adjustment, but also receive external human control commands to instruct the energy storage and power generation system. For example, operators can consume excess electricity to pump water or immediately generate electricity to supplement the power grid's power supply during peak hours, according to the requirements issued by the external power grid; or operators can write new data or program files to the intelligent device 100 through the monitoring node 200.

[0051] In addition, in some embodiments, the monitoring node 200 is connected to the smart device 100, and the smart device 100 is used as a conversion medium to avoid the signal conversion processing between the monitoring node 200 and the execution end (i.e., the circuit conversion device 70, the excitation device 80, or the speed regulation structure 90). The main calculation tasks are still performed by the smart device 100, which reduces the deployment cost of the energy storage power generation system and facilitates maintenance.

[0052] For example, in some embodiments, the monitoring node 200 may be a computer or a control panel, etc.

[0053] In some embodiments, the monitoring node 200 is electrically connected to the excitation device 80 and the speed regulation structure 90, respectively, for monitoring the current status of the excitation device 80 and the speed regulation structure 90. Thus, the monitoring node 200 can display at least some of the current status parameters of the energy storage power generation system in real time. In some embodiments, depending on actual engineering requirements, the monitoring node 200 can be configured to control the excitation device 80 and the speed regulation structure 90, allowing operators to directly operate the excitation device 80 and the speed regulation structure 90 through the monitoring components and receive feedback from them.

[0054] In some embodiments, the energy storage power generation system includes a fourth signaler for measuring the AC voltage of the circuit conversion device 70 and generating a fourth electrical signal. The smart device 100 has a Park's Transformation calculation module for receiving the fourth electrical signal and parsing the fourth electrical signal through the Park's Transformation calculation module to instruct the excitation device 80.

[0055] The aforementioned Parker transformation calculation module refers to a program or circuit capable of performing Parker transformation calculations. The Parker transformation is a mathematical transformation that converts physical quantities such as stator AC current, voltage, and flux linkage from a stationary abc coordinate system to a dq0 coordinate system that rotates synchronously with the rotor. Thus, the intelligent device 100 analyzes the values ​​of the target's second electrical signal based on the input fourth electrical signal, and then instructs the excitation device 80. This ensures that the motor unit 40 operates at the target speed and torque under the first operating condition, and also ensures stable electrical energy generation under the second operating condition, meeting the usage requirements.

[0056] It should be noted that a second electrical signal can also be introduced into this process to participate in the analytical calculation, that is, to achieve closed-loop control of the excitation device 80.

[0057] In this embodiment, the Parker transform decomposes the complex three-phase AC motor control into two independent DC control loops: excitation control and torque control. This simplifies the control logic, reduces the computational workload, and enables the intelligent device 100 to respond quickly to the adjustment control, ultimately achieving millisecond-level control of the energy storage power generation system.

[0058] For example, the excitation device 80 is connected to the circuit conversion device 70 via a high-voltage bus or cable 50, thereby receiving a fourth electrical signal reflecting various parameters of the AC voltage of the circuit conversion device 70.

[0059] In some embodiments, the circuit conversion device 70 is connected to the stator of the motor set 40, the excitation device 80 is an AC excitation system and is connected to the rotor of the motor set 40, and the excitation device 80 includes a frequency converter component, which is used at least for enabling the motor set 40 to start automatically under a first operating condition.

[0060] Specifically, in the initial startup state, the circuit conversion device 70 does not supply power to the stator of the motor unit 40, and the excitation device 80 supplies a low-frequency, low-voltage alternating current to the rotor, generating an alternating magnetic field. According to the principle of electromagnetic induction, a corresponding low-frequency voltage is induced in the stator, and the rotor begins to rotate slowly under the action of electromagnetic torque. As the rotor speed increases, the voltage and frequency of the alternating current are continuously increased until the rotor speed approaches the synchronous speed. Then, the circuit conversion component supplies power to the stator, smoothly connecting the stator to the power grid, thereby completing the self-starting process.

[0061] In this embodiment, the self-starting of the motor unit 40 relies on the frequency conversion component (usually an IGBT device) in the excitation device 80 and the precise control of the intelligent system. No additional auxiliary devices are required, such as no auxiliary motor or SFC (Static Frequency Converter) device to drive it. The motor unit 40 can switch between the first and second operating conditions, simplifying the topology of the energy storage power generation system and reducing the number of devices.

[0062] Furthermore, as an optional embodiment, the self-starting process of the generator set 40 adopts dual closed-loop control. On the one hand, the rotational speed is tracked according to a third electrical signal; on the other hand, the excitation current is tracked according to a second electrical signal. In this way, the generator set 40 starts smoothly, and the stability of the energy storage power generation system is good.

[0063] In some embodiments, the excitation device 80 is also used to achieve electrical braking of the motor set 40 under a first operating condition. Exemplarily, the excitation device 80 achieves electrical braking using a regenerative braking method. When the rotor speed is higher than the synchronous speed of the stator's alternating magnetic field, the motor set 40 transitions from an energy-consuming operating condition to an energy-generating operating condition. The rotor cuts the stator's rotating magnetic field to generate an induced current, which is supplied to the power source (i.e., the external power grid) connected to the excitation device 80. As electrical energy is generated, the rotor's kinetic energy is consumed, the speed decreases, and braking is achieved.

[0064] In this embodiment, the excitation device 80, as a node in the topology, is not only used for excitation, but also for the electrical braking of the motor unit 40, eliminating the need for the motor unit 40 to add an extra structure to achieve braking, thereby reducing the amount of underground engineering construction.

[0065] In some embodiments, the energy storage power generation system also includes a relay protection device, which is connected to the circuit switching device 70, the motor unit 40, and the excitation device 80 respectively. The relay protection device monitors the three components and disconnects them if any one of them malfunctions. The relay protection device helps to improve the stability of the energy storage power generation system.

[0066] For example, the relay protection device is connected to the branch containing the above three components and can switch the branch on and off, thereby disconnecting the branch when any one of them malfunctions, temporarily disconnecting the faulty component from the energy storage power generation system. The circuit switching device 70, the motor unit 40, and the excitation device 80 are all high-voltage components of the energy storage power generation system. The relay protection device can protect both the energy storage power generation system and the operational safety of the operators.

[0067] In some embodiments, the mine includes a shaft and at least one tunnel, with the tunnel laterally connected to the shaft. The shaft forms at least a portion of the waterway system 30. The aforementioned lateral connection means that the tunnel has at least a length component in the horizontal direction and extends to the shaft. If the lower reservoir 20 is constructed based on the existing structural foundation of the tunnel, and the waterway system 30 is also at least partially constructed based on the existing structural foundation of the shaft, then the lower reservoir 20 is also laterally connected to the waterway system 30.

[0068] It should be noted that the shaft mentioned in this specification refers to a structure drilled vertically downwards from the ground in mining operations. The shaft is the main passage connecting the surface and the underground coal seam (vein). The shaft can be a main shaft for transporting minerals, an auxiliary shaft for transporting personnel, equipment, and materials, or a ventilation shaft.

[0069] The motor unit 40 is installed within the portion of the waterway system 30 corresponding to the well shaft. In this embodiment, the motor unit 40 is installed within the portion of the waterway system 30 formed by the well shaft. On the one hand, the well shaft already has a vertically drilled structure, naturally providing a relatively smooth passage space, which is convenient for serving as the space required for water flow in and out, reducing the amount of engineering construction such as waterproofing, seepage prevention, and straightening bends; on the other hand, since the well shaft has been used for mineral or equipment transportation, it is more convenient to use it for hoisting the motor unit 40, and the construction difficulty is lower.

[0070] In some embodiments, please refer to Figure 6 The waterway system 30 has a first opening 30a corresponding to the well shaft. The first opening 30a is laterally connected to the lower reservoir 20. In the second working condition, the first opening 30a is located downstream of the motor unit 40. The pump impeller of the motor unit 40 is lower than the first opening 30a, and the motor unit 40 is located at the bottom of the well shaft.

[0071] It is understandable that the depth of the mine entrance will not exceed the depth of the shaft. As water flows from the shaft into the mine, the bottom space of the shaft must first be filled before it floods into the mine. In the second operating condition, the water from the upper reservoir 10 flows through the motor unit 40 to the first opening 30a, driving the pump wheel of the motor unit 40 to rotate. The height of the motor unit 40 is lower than that of the first opening 30a. On the one hand, the pump wheel of the motor unit 40 is always submerged in water, which is beneficial for the motor unit 40 to generate electricity using the kinetic and pressure energy of the water. On the other hand, in the first operating condition, the first opening 30a is located upstream of the motor unit 40. When the water level of the lower reservoir 20 is higher than that of the motor unit 40, the water in the lower reservoir 20 can naturally flow to the motor unit 40, reducing the idling of the motor unit 40 and improving efficiency.

[0072] In this embodiment, the pump impeller of the motor unit 40 can be a reaction turbine pump impeller, which can adapt to different head heights and is conducive to promoting this engineering design.

[0073] In some embodiments, please refer to Figure 6 and Figure 7 The waterway system 30 includes a water conveyance section 31 and a well section 32 arranged along the water flow direction. The water conveyance section 31 is located on the ground, and the well section 32 is located inside the well. The well section 32 includes an inner sleeve and an outer sleeve that are nested together. It can be understood that the inner sleeve is located inside the outer sleeve, while the outer sleeve is located outside the inner sleeve.

[0074] One end of the inner casing is connected to the water conveyance section 31, and the other end is connected to the outer casing. The outer casing is connected to the first opening 30a. The motor unit 40 is located at the end of the well section 32 away from the water conveyance section 31. The motor unit 40 includes a first channel port 40a and a second channel port 40b for water inlet and outlet. The first channel port 40a is located in the inner casing, and the second channel port 40b is located in the space between the outer casing and the inner casing.

[0075] For example, in the first operating condition, water enters through the second channel port 40b between the outer sleeve and the inner sleeve, and flows out through the first channel port 40a inside the inner sleeve; in the second operating condition, water flows in through the first channel port 40a inside the inner sleeve, and flows out through the second channel port 40b between the outer sleeve and the inner sleeve. Of course, in other embodiments, the flow direction of water in each operating condition may be reversed as described above.

[0076] Compared to related technologies where water flows in a single direction along the waterway under predetermined operating conditions, the energy storage power generation system in this application embodiment can reuse the structure of the well shaft for the inner and outer casings, thereby reversing the direction of water flow without the need for additional pipeline laying, thus reducing the amount of engineering construction and saving costs.

[0077] For example, please refer to Figure 1 The waterway system 30 also includes a surge tank 60. The bottom of the surge tank 60 is connected to the water conveyance section 31. The surge tank 60 is used to stabilize water pressure and buffer water flow impact, which is conducive to the stable operation of the energy storage power generation system.

[0078] For example, the outline of the first channel opening 40a is circular.

[0079] For example, the outline of the second channel opening 40b is annular.

[0080] The various embodiments / implementations provided in this application can be combined with each other without creating contradictions.

[0081] The above description is merely a preferred embodiment of this application and is not intended to limit the application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. An energy storage and power generation system for use in mines, characterized in that, include: An upper reservoir and a lower reservoir, wherein the upper reservoir is located above the lower reservoir and the lower reservoir is located inside the mine shaft; A waterway system and a first signal device, wherein the waterway system connects the upper reservoir and the lower reservoir, and the first signal device is used to measure the head information of the waterway system and generate a first electrical signal; The system includes a motor unit and a circuit conversion device. The circuit conversion device is connected to an external power grid. The motor unit is located on the flow path of the water system and is connected to the circuit conversion device. The motor unit is used to consume the electrical energy of the circuit conversion device to pump water flow under a first operating condition, and to drive the pump wheel to send electrical energy to the circuit conversion device under a second operating condition. An excitation device and a second signal device are provided. The excitation device is connected to the motor set and is used to generate an adjustable magnetic field within the motor set. The second signal device is used to measure the magnetic field strength information of the motor set and generate a second electrical signal. The motor unit has a speed regulating structure and a third signal device. The motor unit has movable guide vanes, which are used to regulate the water flow rate through the motor unit. The speed regulating structure is used to control the opening degree of the movable guide vanes. The third signal device is used to measure the rotational speed information of the motor unit and generate a third electrical signal. The intelligent connection device is electrically connected to the excitation device and the speed regulation structure. The intelligent connection device includes a processor. The intelligent connection device is used to receive the first electrical signal, the second electrical signal and the third electrical signal, and the processor analyzes them to instruct the excitation device to adjust the magnetic field strength of the motor set and instruct the speed regulation structure to adjust the water flow rate through the motor set, respectively.

2. The energy storage power generation system according to claim 1, characterized in that, The energy storage power generation system also includes a monitoring node, which is electrically connected to the smart device. The monitoring node includes a human-machine interaction component for receiving external commands, and is used to receive external commands and instruct the smart device.

3. The energy storage power generation system according to claim 2, characterized in that, The monitoring node is electrically connected to the excitation device and the speed regulation structure respectively, and is used to monitor the current status of the excitation device and the speed regulation structure.

4. The energy storage and power generation system according to claim 1, characterized in that, The energy storage and power generation system includes a fourth signaler, which is used to measure the AC voltage of the circuit conversion device and generate a fourth electrical signal. The intelligent device has a Parker transformation calculation module, which is used to receive the fourth electrical signal and analyze the fourth electrical signal through the Parker transformation calculation module to instruct the excitation device.

5. The energy storage and power generation system according to claim 1, characterized in that, The circuit conversion device is connected to the stator of the motor set, the excitation device is an AC excitation system and is connected to the rotor of the motor set, the excitation device includes a frequency converter, and the frequency converter is used at least for enabling the motor set to start automatically under the first operating condition.

6. The energy storage power generation system according to claim 1, characterized in that, The excitation device is also used to achieve electrical braking of the motor set under the first operating condition.

7. The energy storage power generation system according to claim 1, characterized in that, The energy storage power generation system also includes a relay protection device, which is connected to the circuit conversion device, the motor unit, and the excitation device respectively. The relay protection device is used to monitor the three components and disconnect them when any of the three components malfunctions.

8. The energy storage power generation system according to any one of claims 1-7, characterized in that, The mine includes a shaft and at least one tunnel, the at least one tunnel being laterally connected to the shaft, the shaft forming at least a portion of the waterway system, and the motor unit being disposed within the portion of the waterway system corresponding to the shaft.

9. The energy storage and power generation system according to claim 8, characterized in that, The waterway system has a first opening corresponding to the portion of the well shaft. The first opening is laterally connected to the lower reservoir. In the second operating condition, the first opening is located downstream of the motor unit. The pump impeller of the motor unit is positioned below the first opening, and the motor unit is located at the bottom of the well shaft.

10. The energy storage and power generation system according to claim 9, characterized in that, The waterway system includes a water conveyance section and a well section arranged along the water flow direction. The water conveyance section is located on the ground, and the well section is located inside the well. The well section includes an inner sleeve and an outer sleeve that are nested together. One end of the inner sleeve is connected to the water conveyance section, and the other end is connected to the outer sleeve. The outer sleeve is connected to the first opening. The motor unit is located at one end of the well section away from the water conveyance section. The motor unit includes a first channel port and a second channel port for water inlet and outlet. The first channel port is located in the inner sleeve, and the second channel port is located in the empty area between the outer sleeve and the inner sleeve.

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