Gravity energy storage system and method for expressway service area

Abstract

The invention discloses a gravity energy storage system for an expressway service area. The gravity energy storage system comprises a gravity energy storage module and an energy management module, the gravity energy storage module comprises a vertical tower arranged at the corner of a service area or an underground area, a movable gravity block contained in the vertical tower, a lifting driving device and a power generation device. The energy management module comprises an intelligent controller and a bidirectional converter, the intelligent controller is in communication connection with the lifting driving device and the power generation device and used for controlling charging and discharging of the system, the alternating-current side of the bidirectional converter is connected with a service area power grid, and the direct-current side of the bidirectional converter is connected with the power generation device. According to the invention, the charging peak and the photovoltaic output are accurately matched by utilizing the corner and underground area layout, the power and the capacity in space, the on-site peak clipping and valley filling and the efficient green power consumption are realized, the power grid capacity expansion is reduced through peak-valley arbitrage, the participation in demand response and carbon transaction is realized, the economic benefit is remarkable, and the power service area is assisted to realize near-zero carbon operation.

Description

Technical Field

[0001] This invention relates to a gravity energy storage system and method for highway service areas, belonging to the field of energy storage technology. Background Technology

[0002] With the increasing number of charging stations, lighting, air conditioning, and catering equipment in highway service areas, the demand for electricity in these areas is growing daily. Currently, service areas mainly rely on the main power grid for power supply, which presents problems such as high power supply pressure during peak hours, high electricity costs, and a lack of reliable backup power sources during grid failures. Meanwhile, service areas are usually equipped with photovoltaic power generation facilities, but photovoltaic power generation is intermittent and unstable, and the generated electricity cannot be effectively stored and utilized.

[0003] Among existing energy storage technologies, lithium battery energy storage suffers from high cost, short lifespan, and poor safety; pumped hydro storage has stringent geographical requirements and is unsuitable for applications in highway service areas with limited space and fixed layouts. Gravity energy storage, as a physical energy storage method, has advantages such as long-term energy storage, environmental friendliness, high safety, and long lifespan. However, most existing gravity energy storage systems are designed for large-scale grid energy storage, and their scale, layout, and operation modes are incompatible with the unique spatial compactness, load fluctuations, and diverse energy consumption characteristics of highway service areas. Therefore, there is an urgent need to develop a gravity energy storage system specifically suitable for highway service area scenarios to solve the aforementioned technical problems. Summary of the Invention

[0004] The purpose of this invention is to provide a gravity energy storage system and a gravity energy storage method for highway service areas. This invention can realize the effective storage and rational utilization of photovoltaic power generation in service areas, reduce the dependence of service areas on the main power grid, reduce electricity costs, improve power supply reliability, and achieve efficient integration of the energy storage system with the service area space. This solves the problems of high power supply pressure, high cost, and insufficient reliability caused by the dependence of service area power supply on the main power grid, as well as the inability to effectively absorb and utilize distributed energy sources such as photovoltaics.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: a gravity energy storage system for highway service areas, comprising a gravity energy storage module and an energy management module;

[0006] The gravity energy storage module includes a vertical tower installed at the corner of the service area or in an underground area, a movable gravity block housed within the vertical tower, a lifting drive device, and a power generation device. The lifting drive device includes an electric winch installed at the top of the vertical tower, which is connected to a car via a steel wire rope. The car is used to carry the gravity block. The power generation device is connected to the car and is used to convert gravitational potential energy into electrical energy when the gravity block drives the car to descend.

[0007] The energy management module includes an intelligent controller and a bidirectional converter. The intelligent controller is communicatively connected to the lifting drive device and the power generation device and is used to control the charging and discharging of the system. The AC side of the bidirectional converter is connected to the service area power grid, and its DC side is connected to the power generation device.

[0008] The aforementioned system also includes a photovoltaic coordination module, which includes photovoltaic power generation components installed in the idle space of the service area and a photovoltaic-energy storage coordination control unit. The photovoltaic power generation components are connected to the service area power grid through the bidirectional converter, and the photovoltaic-energy storage coordination control unit is communicatively connected to the intelligent controller.

[0009] In the aforementioned system, the power generation device is connected to the car via a transmission mechanism, which is a gear-rack transmission mechanism.

[0010] In the aforementioned system, the main body of the gravity block is made of steel slag concrete, the interior of the main body of the gravity block is filled with high-density alloy particles, and its surface is coated with a self-lubricating coating.

[0011] The aforementioned system further includes an auxiliary function module, which comprises at least one of the following units:

[0012] An emergency power supply unit is connected to the intelligent controller and the critical load power distribution circuit;

[0013] The vehicle linkage unit is communicatively connected to the intelligent controller and the electric vehicle charging piles in the service area.

[0014] The waste heat recovery device includes a heat exchange unit and a heat energy utilization circuit. The heat exchange unit is located near the heating component of the electric winch and / or the power generation device to collect waste heat generated during equipment operation. The heat energy utilization circuit delivers the collected heat energy to the hot water supply system or heating system of the service area.

[0015] In the aforementioned system, the vertical tower has a modular structure, including at least one independent energy storage tower. Each energy storage tower is equipped with multiple parallel lifting channels, and the lifting channels are equipped with lifting drive devices, power generation units, and gravity blocks.

[0016] In the aforementioned system, the energy storage tower is a reinforced concrete frame shear wall structure, and its internal space is divided into a lower storage area located underground, an upper storage area located above ground, and a lifting channel that vertically connects the storage areas. The gravity block is placed in the lower storage area and / or the upper storage area.

[0017] In the aforementioned system, both the lower and upper storage areas are equipped with horizontal transport trolleys and track systems, which are used to transfer the gravity blocks between the lower / upper storage areas and the lifting channels.

[0018] A power management method for highway service areas, applied to the aforementioned power storage system, the method comprising the following steps:

[0019] S1. Monitoring: Real-time monitoring of the service area's power load demand, photovoltaic power generation, grid electricity price, and grid operation status through intelligent controllers;

[0020] S2, Charging Control: When it is detected that the power grid is in a period of low electricity price, or the photovoltaic power generation exceeds the real-time electricity demand of the service area, the electric winch is controlled to start, and the car carrying the gravity block is lifted to the predetermined height of the top of the vertical tower, and the electrical energy is converted into gravitational potential energy for storage.

[0021] S3, Discharge Control: When it is detected that the power grid is in a peak electricity price period, the photovoltaic power generation is insufficient, or the power load of the service area suddenly increases, the gravity block is controlled to descend under the action of gravity, driving the power generation device to operate and generate electricity, and the generated power is transmitted to the power grid of the service area through the bidirectional converter to supplement the power supply.

[0022] The charging control step and the discharging control step are executed by the intelligent controller after optimizing the data obtained from the monitoring step based on artificial intelligence algorithms and digital twin models.

[0023] The aforementioned energy management methods also include:

[0024] Photovoltaic synergy steps: The photovoltaic-energy storage synergy control unit controls the flow of energy generated by the photovoltaic power generation modules. When there is a surplus of photovoltaic power generation, the surplus energy is given priority to the charging control step; when there is a shortage of photovoltaic power generation, the discharging control step is executed first.

[0025] Waste heat recovery step: The heat generated during the operation of the electric winch and / or power generation device is collected by the waste heat recovery device, and the recovered heat energy is delivered to the hot water supply system or heating system of the service area for utilization;

[0026] Emergency response steps: When the monitoring steps detect a power grid failure, immediately switch to emergency power supply mode, control the gravity energy storage system to stop power exchange with the power grid, and prioritize power supply to at least one critical load among emergency lighting, communication equipment and charging piles in the service area;

[0027] Vehicle linkage steps: The vehicle linkage unit communicates with the electric vehicle charging pile. During peak grid hours and when the gravity energy storage system has sufficient power, the energy storage system is prioritized to supply power to the charging pile. At the same time, electric vehicles with V2G functionality can be scheduled to feed power back to the gravity energy storage system or the service area grid.

[0028] Compared with the prior art, the present invention has at least the following beneficial effects:

[0029] (1) The system of the present invention optimizes the spatial layout for the compact service area, places the vertical tower (1) in the corner or underground, and combines modular design to achieve efficient integration with existing facilities. Its power and capacity can accurately match the load characteristics of large service areas, effectively shaving peaks and filling valleys, and avoiding grid expansion.

[0030] (2) This invention is based on physical gravitational potential energy conversion, without the risk of combustion or explosion of chemical batteries, without pollution, inherently safe, suitable for densely populated areas, with long mechanical structure life, good environmental adaptability, and simple maintenance.

[0031] (3) This invention uses an intelligent controller combined with artificial intelligence and digital twin technology to achieve accurate prediction and optimized scheduling of photovoltaic power generation, grid status and load demand, which greatly improves the local consumption rate of clean energy such as photovoltaics, and integrates waste heat recovery to further improve overall energy efficiency.

[0032] (4) This invention integrates auxiliary functions such as emergency power supply and vehicle linkage, which not only ensures the reliability of power supply, but also builds a micro grid ecosystem in the service area, improving the comprehensive service capabilities and energy management level.

[0033] (5) This invention achieves significant economic benefits through peak-valley arbitrage, demand response, saving power grid expansion investment, and participating in green electricity trading. It uses materials such as steel slag concrete to realize the resource utilization of solid waste, and the system operates with zero carbon emissions, which helps to build near-zero carbon service areas. Attached Figure Description

[0034] Figure 1 This is the general layout plan of the highway service area according to the present invention;

[0035] Figure 2 This is an elevation view of a highway service area according to the present invention;

[0036] Figure 3 This is a floor plan of the upper warehouse of the present invention;

[0037] Figure 4 This is a plan view of the lower warehouse of the present invention;

[0038] Figure 5 This is a cross-sectional view of the present invention;

[0039] Figure 6 This is a schematic diagram of the energy storage and power generation process of the present invention;

[0040] Figure 7 This is a system diagram of the present invention.

[0041] Attached reference numerals: 1-vertical tower, 2-gravity block, 3-car, 4-energy storage tower, 5-lifting channel, 6-lower storage area, 7-upper storage area.

[0042] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. Detailed Implementation

[0043] Embodiment 1 of the present invention: A gravity energy storage system for highway service areas, comprising a gravity energy storage module, an energy management module, a photovoltaic synergy module, and an auxiliary function module, wherein:

[0044] The gravity energy storage module includes a vertical tower 1 installed at the corner of the service area or in an underground area, a movable gravity block 2 housed in the vertical tower 1, a lifting drive device, and a power generation device.

[0045] The lifting drive device includes an electric winch installed at the top of the vertical tower 1. The electric winch is connected to a car 3 via a steel wire rope. The car 3 is used to carry the gravity block 2.

[0046] The power generation device is connected to the car 3 and is used to convert gravitational potential energy into electrical energy when the gravity block 2 drives the car 3 to descend.

[0047] The energy management module includes an intelligent controller and a bidirectional converter:

[0048] The intelligent controller is communicatively connected to the lifting drive device and the power generation device to control the charging and discharging of the system.

[0049] The AC side of the bidirectional converter is connected to the service area power grid, and its DC side is connected to the power generation device.

[0050] The photovoltaic (PV) co-operation module includes PV power generation components installed in unused spaces within the service area, and a PV-energy storage co-operation control unit.

[0051] The photovoltaic power generation modules are connected to the service area power grid via the bidirectional converter.

[0052] The photovoltaic-energy storage collaborative control unit is communicatively connected to the intelligent controller.

[0053] The auxiliary function module includes at least one of the following units:

[0054] An emergency power supply unit is connected to the intelligent controller and the critical load power distribution circuit;

[0055] The vehicle linkage unit is communicatively connected to the intelligent controller and the electric vehicle charging piles in the service area.

[0056] The waste heat recovery device includes a heat exchange unit and a heat energy utilization circuit. The heat exchange unit is located near the heating component of the electric winch and / or the power generation device to collect waste heat generated during equipment operation. The heat energy utilization circuit delivers the collected heat energy to the hot water supply system or heating system of the service area.

[0057] Specifically, the generator is not directly connected to the car 3, but is linked through a high-precision, high-reliability gear-rack transmission mechanism. The rack is fixedly installed on the side wall of the car 3 or on a dedicated guide frame and moves vertically with the car 3. The gear is installed on the input shaft of the generator and meshes with the rack. When the car 3 descends, the rack fixed on it moves accordingly, driving the meshing gear to rotate. The rotational motion of the gear is directly transmitted to the generator rotor through a coupling. This transmission method converts the linear motion of the car 3 into the rotational motion required by the generator rotor, and has the advantages of high transmission efficiency, rapid response, and large load-bearing capacity.

[0058] Specifically, the main body of gravity block 2 is made of steel slag concrete, and its standard shape can be a regular cuboid. This regular shape facilitates tight stacking in the loading area, maximizing space utilization and making it easy for transport trolleys to grab and move. To further increase the mass per unit volume, the main body of gravity block 2 is filled with high-density alloy particles. Specifically, high-density alloy particles, such as tungsten alloy particles, lead particles, or barite aggregates, can be pre-embedded inside before the main concrete is poured. These particles play a role in increasing weight, so that the mass of gravity block 2 is greatly increased while maintaining the same external dimensions. This composite structure maximizes potential energy storage within a limited installation space. To ensure smooth operation and reduce wear during long-term, high-frequency horizontal transportation and vertical lifting, the surface of gravity block 2 is coated with a self-lubricating coating. This coating can significantly reduce the coefficient of friction, reduce frictional resistance and wear between the block and metal parts, not only reducing drive energy consumption but also extending the service life of gravity block 2 itself and the transportation equipment.

[0059] Specifically, the vertical tower 1 is a modular structure, including at least one independent energy storage tower 4. Each energy storage tower 4 has multiple parallel lifting channels 5, and each lifting channel 5 corresponds to a lifting drive device, a power generation unit, and a gravity block 2. The energy storage tower 4 is a reinforced concrete frame shear wall structure, and its internal space is divided into an underground lower storage area 6, an above-ground upper storage area 7, and lifting channels 5 that vertically connect the storage areas. The gravity block 2 is placed in the lower storage area 6 and / or the upper storage area 7. Both the lower storage area 6 and the upper storage area 7 are equipped with horizontal transport trolleys and track systems, which are used to transfer the gravity block 2 between the lower storage area 6 / upper storage area 7 and the lifting channels 5.

[0060] The internal space of energy storage tower 4 is further divided into a top-floor equipment room and a ground-floor equipment and conversion area. This ground floor is the main drive and control system floor, where electric winches, main drive shafts, control cabinets, and cooling equipment are centrally installed. Placing the power source at the top conforms to the mechanical logic of gravity lifting and facilitates centralized equipment maintenance. The ground-floor equipment and conversion area mainly houses the generator room, electrical distribution room, and the entrance / exit of the lifting channel 5. The generator is connected to a rack and pinion mechanism passing through the floor slab to achieve energy conversion.

[0061] Among them, the horizontal transport trolley and track system is the key hub equipment for realizing the transfer of gravity block 2 between the stacking area and the lifting channel 5. The system mainly consists of two parts: a fixed track network and an automated guided vehicle (AGV) or rail shuttle (RGV) running on it. The track network covers the storage locations of the entire stacking area in a grid or ring layout and the transfer docking station connected to the entrance / exit of the lifting channel 5.

[0062] The orbital system structure includes:

[0063] Track beams: Heavy-duty steel rails or special H-beams are used and fixed to the concrete floor slab of the loading area with high-strength anchor bolts. The track must have extremely high straightness and levelness to ensure that the trolley runs smoothly.

[0064] Power supply and communication sliding contact line: A safety sliding contact line is laid along one side or the middle of the track to provide continuous power to the trolley in operation. At the same time, a communication data line is laid in parallel or wireless communication is used to realize real-time data exchange between the trolley and the central control system.

[0065] Positioning and detection devices: Precise positioning tags, such as RFID tags, QR code marks, and photoelectric sensors, are installed at key nodes along the track to confirm the precise stopping position of the trolley and monitor its operating status.

[0066] Horizontal transport trolley structure:

[0067] Vehicle frame: A rigid structure welded from high-strength steel plates, capable of bearing the weight of one or more gravity blocks 2.

[0068] Drive unit: Usually uses servo motor to drive the wheels, which features smooth start and stop and precise speed adjustment. The wheels are solid polyurethane wheels or steel wheels, suitable for indoor environments.

[0069] Lifting and gripping mechanism: This is the core functional component of the trolley, used to pick up and put down the gravity block 2. It can adopt a forklift type or a clamping type structure. Specifically, the forklift type is similar to a forklift, with forks that can insert into the bottom pallet of the gravity block 2, and lifting is achieved through hydraulic or electric screws. The clamping type is suitable for gravity blocks 2 with flat sides, using hydraulic clamping arms to grip and transport them from both sides.

[0070] The vehicle is also equipped with an onboard controller, navigation sensors (to read track positioning tags), a wireless communication module, and safety sensors (such as collision avoidance lidar). It receives instructions from the central control system, autonomously completes path planning, driving, precise positioning, performs grab / drop actions, and provides status feedback.

[0071] The workflow of the horizontal transport trolley is as follows: When the intelligent controller determines that charging or discharging is needed, it issues a transfer instruction to the horizontal transport system; the system dispatches an idle trolley to the designated storage location; the trolley precisely positions itself in front of the target gravity block 2, performs a grabbing operation, and smoothly transfers gravity block 2 onto the trolley; the trolley transports gravity block 2 along the planned path to the designated docking station of the lifting channel 5; at the docking station, the trolley precisely aligns with the waiting car 3, and then transfers gravity block 2 into the car 3; after the transfer is completed, the trolley returns empty to the standby area or performs the next task. Reverse workflow: When it is necessary to transport gravity block 2 back from the lifting channel 5 to the storage location, the reverse operation is performed.

[0072] Embodiment 2 of the present invention:

[0073] This embodiment provides a gravity energy storage system for large highway service areas, as detailed below:

[0074] System Overall Structure and Layout: The system is integrated within the highway service area, making full use of the service area's corners or underground spaces. The core facility consists of two modular gravity energy storage towers arranged side-by-side, each tower occupying an area of ​​approximately 24 meters × 24 meters and a height of 96 meters. This layout does not occupy core service spaces such as parking lots, charging areas, or dining areas. Photovoltaic power generation modules with a total capacity of approximately 1.72MW are installed in unused areas such as the service area parking lot roof and building roofs, forming a synergistic energy supply system of "photovoltaics + energy storage".

[0075] Gravity energy storage modules: Each gravity energy storage tower is a reinforced concrete frame-shear wall structure with 24 floors above ground and 4 floors underground, and its seismic design meets the requirements of the "Code for Seismic Design of Buildings" (GB50011-2010). Its internal functional zoning is as follows:

[0076] Underground section (B1-B4 levels): This is the lower storage area 6, with a floor height of 4.0 meters, used to store gravity blocks 2 in a low potential energy state.

[0077] Floors 1-19 above ground: mainly hollow elevator shaft 5, which is the passage for the vertical movement of the car 3 and the gravity block 2.

[0078] Floors 20-23 above ground: This is the upper storage area 7, with a floor height of 4.0 meters, used to store gravity blocks 2 that have been raised to a high potential energy state.

[0079] The 24th floor above ground is the equipment room, which houses the main drive equipment and control system cabinets for electric winches.

[0080] First floor (1st floor above ground): Contains the generator room and some electrical equipment.

[0081] Gravity Block 2 and the Transportation System:

[0082] Gravity Block 2: Constructed from high-density steel slag concrete, each block measures 1.5m (length) × 1.0m (width) × 2.5m (height), weighs approximately 16 tons, and has a density of up to 42kN / m³. 3 To optimize performance, tungsten alloy particles can be incorporated into its interior to further increase energy density, and a special self-lubricating coating is applied to its surface to reduce friction. A total of 1280 such gravity blocks are configured in the entire system.

[0083] Horizontal transport system: A circular track network and automated guided vehicle (RGV) trolleys are laid inside both the upper storage area 7 and the lower storage area 6. This system is responsible for the automated transfer of gravity blocks 2 between the warehouse storage location and the docking position of the car 3 in the lifting channel 5.

[0084] Lifting and power generation systems:

[0085] Lifting drive unit: A high-performance electric winch is installed in the machine room at the top of each tower. The winch is connected to the car 3 located in the lifting channel 5 via a high-strength steel wire rope. Each energy storage tower 4 contains 8 independent lifting units, i.e., 8 cars 3. The car 3 runs at a speed of approximately 2 meters per second.

[0086] Power generation unit and transmission mechanism: At the bottom of each lifting channel 5, a high-power synchronous generator (e.g., Siemens 1FC6404-6LA42 model, rated power 3.825MW) is installed. The generator is linked to the car 3 through a high-precision, high-efficiency gear-rack transmission mechanism. When the car 3 descends carrying the gravity block 2, the rack drives the gear to rotate, thereby driving the generator rotor to generate electricity.

[0087] Energy Management Module:

[0088] Intelligent Controller: Employs an intelligent control platform based on an industrial computer, incorporating built-in artificial intelligence algorithms and digital twin software. The digital twin model maps the power grid structure, load characteristics, and photovoltaic output of the service area in real time for simulation and optimized dispatching. The controller connects to winches, generators, converters, and all sensors via a communication network.

[0089] Bidirectional converter: Employing a high-capacity power conversion system (PCS), its AC side is connected to the 10kV distribution network of the service area, while its DC side is connected to the output of each generating unit after rectification / inversion. It enables bidirectional energy flow between the energy storage AC grid and the DC generator, and has seamless grid-connected / off-grid switching capabilities.

[0090] Photovoltaic collaborative module:

[0091] The direct current generated by the photovoltaic power generation modules is converted into alternating current by their respective photovoltaic inverters and then connected to the low-voltage power distribution system of the service area. The photovoltaic-energy storage collaborative control unit, as a software functional module within the intelligent controller, compares the photovoltaic output with the real-time load of the service area in real time. Its control method is as follows: the surplus photovoltaic power is first rectified by the bidirectional converter and used to drive the winch to charge the energy storage system; when the photovoltaic power is insufficient, the energy storage system is instructed to discharge to supplement it.

[0092] Auxiliary function modules:

[0093] Emergency power supply unit: Continuously monitors grid voltage and frequency. Once a grid fault is detected, it will issue a command within milliseconds to switch the bidirectional converter to off-grid mode and control the energy storage system to supply power only to pre-defined critical load circuits, such as emergency lighting, communication base stations, and important charging piles.

[0094] Waste heat recovery device: Plate heat exchangers are installed at heat source locations such as the motor casing of the electric winch and the cooling air duct of the power generation unit as heat exchange units. After the circulating working fluid absorbs waste heat, it is transported to the hot water storage tank or heating heat exchange station in the service area through the heat energy utilization loop for daily hot water or winter space heating. The heat energy utilization loop adopts insulated pipes.

[0095] Vehicle Interconnection Unit: The intelligent controller establishes a communication connection with all electric vehicle charging stations within the service area through an IoT gateway or charging station operation and management platform. This unit can not only obtain charging load information, but also send dispatch instructions to charging stations and electric vehicles that support the V2G (Vehicle-to-Grid) protocol.

[0096] In conjunction with the hardware described above in this embodiment, the system operates according to the following process:

[0097] Step 1: The intelligent controller continuously collects data such as the grid's time-of-use electricity price, real-time load power, photovoltaic power generation, and energy storage system's state of charge, and inputs them into the digital twin model for ultra-short-term prediction. Based on artificial intelligence algorithms, it dynamically generates charging and discharging plans with optimal cost or reliability.

[0098] Step 2: Execute using multiple operating modes

[0099] Mode A: Off-peak electricity charging / photovoltaic charging: During off-peak electricity prices from 23:00 to 7:00 the next day, or when there is a surplus of photovoltaic power during the day, the controller initiates the charging program. The RGV trolley transports the gravity block 2 from the lower storage area into the car 3, and the winch consumes electricity to lift the car 3 to the upper storage area, completing the energy storage.

[0100] Mode B: Peak Discharge / Load Tracking: During peak electricity consumption and price periods from 10:00-15:00 during the day or 18:00-21:00 in the evening, the controller initiates the discharge program. The car 3 in the upper depot descends under gravity, driving the generator to generate electricity. The electrical energy is fed into the power grid through the converter, smoothing out peak loads.

[0101] Mode C: Emergency Power Supply: When the power grid fails, the system automatically switches to off-grid emergency mode, supplying power only to critical loads until the power grid is restored.

[0102] Mode D: During extreme peak periods or when the energy storage capacity is insufficient, the controller can send a "discharge" request to the electric vehicle connected to the V2G charging station through the vehicle linkage unit, aggregating the energy of the electric vehicle battery as a temporary supplement.

[0103] Mode E: Waste Heat Recovery: During all the periods mentioned above involving the operation of the winch and generator, the waste heat recovery device works synchronously to recover waste heat.

[0104] Example Result: The system designed in this example has a rated power of 5MW and an energy storage capacity of 5MWh (16 modules in parallel). The overall system cycle efficiency can reach 85%. Simulation analysis shows that this system can achieve:

[0105] Peak shaving and valley filling: Approximately 4 MWh of electricity can be transferred daily, covering 1-2 peak periods in the service area and reducing peak load by approximately 15%-30%.

[0106] Photovoltaic consumption: It can increase the self-consumption rate of local photovoltaic power generation in the service area from about 55% to more than 90%.

[0107] Economic benefits: In regions where the peak-valley electricity price difference is 0.8 yuan / kWh, the annual income from peak-valley arbitrage alone can reach over one million yuan. Combined with demand response and capacity reduction benefits, the static investment payback period is approximately 12-18 years.

[0108] Safe and environmentally friendly: No chemical pollution throughout its entire life cycle, it can replace about 1.2 million kWh of electricity from the power grid annually, reduce carbon dioxide emissions by nearly 1,000 tons, and operate at a noise level of less than 60 decibels.

[0109] Embodiment 3 of the present invention:

[0110] A power management method for highway service areas, applied to the aforementioned power storage system, the method comprising the following steps:

[0111] S1. Monitoring: Real-time monitoring of the service area's power load demand, photovoltaic power generation, grid electricity price, and grid operation status through intelligent controllers;

[0112] S2, Charging control: When it is detected that the power grid is in a period of low electricity price, or the photovoltaic power generation exceeds the real-time electricity demand of the service area, the electric winch is controlled to start, and the car 3 carrying the gravity block 2 is lifted to the top of the vertical tower 1 at a predetermined height, and the electrical energy is converted into gravitational potential energy for storage.

[0113] S3, Discharge Control: When it is detected that the power grid is in a peak electricity price period, the photovoltaic power generation is insufficient, or the power load of the service area suddenly increases, the gravity block 2 is controlled to descend under the action of gravity, driving the power generation device to operate and generate electricity, and the generated power is transmitted to the power grid of the service area through the bidirectional converter to supplement the power supply.

[0114] The charging control step and the discharging control step are executed by the intelligent controller after optimizing the data obtained from the monitoring step based on artificial intelligence algorithms and digital twin models.

[0115] The aforementioned energy management methods also include:

[0116] Photovoltaic synergy steps: The photovoltaic-energy storage synergy control unit controls the flow of energy generated by the photovoltaic power generation modules. When there is a surplus of photovoltaic power generation, the surplus energy is given priority to the charging control step; when there is a shortage of photovoltaic power generation, the discharging control step is executed first.

[0117] Waste heat recovery step: The heat generated during the operation of the electric winch and / or power generation device is collected by the waste heat recovery device, and the recovered heat energy is delivered to the hot water supply system or heating system of the service area for utilization;

[0118] Emergency response steps: When the monitoring steps detect a power grid failure, immediately switch to emergency power supply mode, control the gravity energy storage system to stop power exchange with the power grid, and prioritize power supply to at least one critical load among emergency lighting, communication equipment and charging piles in the service area;

[0119] Vehicle linkage steps: The vehicle linkage unit communicates with the electric vehicle charging pile. During peak grid hours and when the gravity energy storage system has sufficient power, the energy storage system is prioritized to supply power to the charging pile. At the same time, electric vehicles with V2G functionality can be scheduled to feed power back to the gravity energy storage system or the service area grid.

[0120] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent changes, modifications, or substitutions made by those skilled in the art to the system structure, parameters, and control logic within the technical principles disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the claims.

Claims

1. A gravity energy storage system for highway service areas, characterized in that, Includes gravity energy storage module and energy management module; The gravity energy storage module includes a vertical tower (1) installed at the corner of the service area or in the underground area, a movable gravity block (2) housed in the vertical tower (1), a lifting drive device, and a power generation device; The lifting drive device includes an electric winch installed on the top of the vertical tower (1), the electric winch being connected to a car (3) via a steel wire rope, the car (3) being used to carry the gravity block (2); The power generation device is connected to the car (3) and is used to convert gravitational potential energy into electrical energy when the gravity block (2) drives the car (3) to descend. The energy management module includes an intelligent controller and a bidirectional converter. The intelligent controller is communicatively connected to the lifting drive device and the power generation device and is used to control the charging and discharging of the system. The AC side of the bidirectional converter is connected to the service area power grid, and its DC side is connected to the power generation device.

2. The system according to claim 1, characterized in that, It also includes a photovoltaic co-processing module, which includes photovoltaic power generation components installed in the idle space of the service area and a photovoltaic-energy storage co-processing control unit. The photovoltaic power generation components are connected to the service area power grid through the bidirectional converter, and the photovoltaic-energy storage co-processing control unit is communicatively connected to the intelligent controller.

3. The system according to claim 1 or 2, characterized in that, The power generation device is connected to the car (3) through a transmission mechanism, which is a gear-rack transmission mechanism.

4. The system according to claim 1 or 2, characterized in that, The main body of the gravity block (2) is made of steel slag concrete, and the interior of the main body of the gravity block (2) is filled with high-density alloy particles, and its surface is coated with a self-lubricating coating.

5. The system according to claim 1 or 2, characterized in that, It also includes an auxiliary function module, which comprises at least one of the following units: An emergency power supply unit is connected to the intelligent controller and the critical load power distribution circuit; The vehicle linkage unit is communicatively connected to the intelligent controller and the electric vehicle charging piles in the service area. The waste heat recovery device includes a heat exchange unit and a heat energy utilization circuit. The heat exchange unit is located near the heating component of the electric winch and / or the power generation device to collect waste heat generated during equipment operation. The heat energy utilization circuit delivers the collected heat energy to the hot water supply system or heating system of the service area.

6. The system according to claim 1 or 2, characterized in that, The vertical tower (1) is a modular structure, including at least one independent energy storage tower (4). Each energy storage tower (4) is equipped with multiple parallel lifting channels (5). The lifting channels (5) are equipped with corresponding lifting drive devices, power generation units and gravity blocks (2).

7. The system according to claim 6, characterized in that, The energy storage tower (4) is a reinforced concrete frame shear wall structure. Its internal space is divided into a lower storage storage area (6) located underground, an upper storage storage area (7) located on the ground, and a lifting channel (5) that vertically connects the storage areas. The gravity block (2) is placed in the lower storage storage area (6) and / or the upper storage storage area (7).

8. The system according to claim 7, characterized in that, Both the lower storage area (6) and the upper storage area (7) are equipped with horizontal transport trolleys and track systems. The horizontal transport trolleys and track systems are used to transfer the gravity block (2) between the lower storage area (6) / upper storage area (7) and the lifting channel (5).

9. A power management method for highway service areas, characterized in that, Applied to the power storage system as described in any one of claims 1-8, the method comprises the following steps: S1. Monitoring: Real-time monitoring of the service area's power load demand, photovoltaic power generation, grid electricity price, and grid operation status through intelligent controllers; S2, Charging control: When it is detected that the power grid is in a period of low electricity price, or the photovoltaic power generation exceeds the real-time electricity demand of the service area, the electric winch is controlled to start, and the car (3) carrying the gravity block (2) is lifted to the top of the vertical tower (1) at a predetermined height, and the electrical energy is converted into gravitational potential energy for storage. S3, Discharge control: When it is detected that the power grid is in a peak electricity price period, the photovoltaic power generation is insufficient, or the power load of the service area suddenly increases, the gravity block (2) is controlled to descend under the action of gravity, the power generation device is driven to operate and generate electricity, and the generated power is transmitted to the power grid of the service area through the bidirectional converter to supplement the power supply. The charging control step and the discharging control step are executed by the intelligent controller after optimizing the data obtained from the monitoring step based on artificial intelligence algorithms and digital twin models.

10. The energy management method according to claim 9, characterized in that, Also includes: Photovoltaic synergy steps: The photovoltaic-energy storage synergy control unit controls the flow of energy generated by the photovoltaic power generation modules. When there is a surplus of photovoltaic power generation, the surplus energy is given priority to the charging control step; when there is a shortage of photovoltaic power generation, the discharging control step is executed first. Waste heat recovery step: The heat generated during the operation of the electric winch and / or power generation device is collected by the waste heat recovery device, and the recovered heat energy is delivered to the hot water supply system or heating system of the service area for utilization; Emergency response steps: When the monitoring steps detect a power grid failure, immediately switch to emergency power supply mode, control the gravity energy storage system to stop power exchange with the power grid, and prioritize power supply to at least one critical load among emergency lighting, communication equipment and charging piles in the service area; Vehicle linkage steps: The vehicle linkage unit communicates with the electric vehicle charging pile. During peak grid hours and when the gravity energy storage system has sufficient power, the energy storage system is prioritized to supply power to the charging pile. At the same time, electric vehicles with V2G functionality can be scheduled to feed power back to the gravity energy storage system or the service area grid.

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