Electrically conductive carbon concrete base mixed energy storage collaborative frequency modulation system and method

Abstract

The present application relates to the technical field of hybrid energy storage of power system, and particularly relates to a conductive carbon concrete base hybrid energy storage coordinated frequency modulation system and method, which comprises a conductive carbon concrete energy storage main body arranged in a conductive carbon concrete base power unit and a plurality of parallel electrodes embedded in the conductive carbon concrete energy storage main body; a container lithium battery energy unit comprises a lithium battery cluster in a container and a battery management system; an intelligent collaborative controller is used for decomposing a total power instruction into power components corresponding to different response time scales, and distributing an instantaneous power component corresponding to primary frequency modulation after decomposition to the conductive carbon concrete base power unit, and distributing a sustained power component corresponding to secondary frequency modulation to the container lithium battery energy unit. The present application realizes the integration of structure bearing and power energy storage of the concrete base, and through collaborative control, the power type energy storage and the energy type energy storage are coordinated in time scale, so that the response speed of frequency modulation is improved and the lithium battery cycle attenuation is reduced.

Description

Technical Field

[0001] This invention relates to the field of hybrid energy storage technology for power systems, and in particular to a hybrid energy storage and frequency regulation system and method based on conductive carbon concrete foundation. Background Technology

[0002] Containerized lithium battery energy storage systems have become key equipment for energy management, peak shaving and frequency regulation on the grid side and new energy power plant side. At present, such energy storage systems usually use a single lithium battery as the energy storage medium, and they face multiple technical challenges in engineering applications.

[0003] In grid frequency regulation scenarios, primary frequency regulation requires energy storage devices to respond to frequency fluctuations and provide short-term high-power support within seconds, placing extremely high demands on power response characteristics. Secondary frequency regulation, on the other hand, requires energy throughput capacity for several minutes to tens of minutes. Single lithium battery energy storage systems are constrained by the electrochemical reaction rate and the adjustment speed of the battery management system (BMS), with response times typically exceeding hundreds of milliseconds. This makes it difficult to meet the requirements of primary frequency regulation for instantaneous power response at the millisecond to second level. If lithium batteries are forced to frequently perform rapid, shallow charge and discharge frequency regulation tasks, it will severely exacerbate cell cycle degradation, sacrificing their core lifespan and economy for energy time shifting, resulting in an irreconcilable contradiction between frequency regulation performance and energy storage lifespan.

[0004] Meanwhile, the concrete base of existing energy storage containers serves only as a passive load-bearing structure, occupying a large area but lacking any active electrical functions, resulting in a huge waste of space and materials. Although supercapacitors can match the high power demand of primary frequency regulation, independent supercapacitor energy storage systems are expensive, bulky, and require additional land, making them cost-effective for deployment in large-scale energy storage power plants. There is a lack of low-cost carriers that can be deeply integrated with existing infrastructure. Therefore, how to achieve the synergy of high power response and long-term energy dispatch within the limited space of existing energy storage containers has become a technical bottleneck restricting the development of this field. Summary of the Invention

[0005] To address the above technical problems, this invention provides a conductive carbon concrete base hybrid energy storage and coordinated frequency regulation system and method.

[0006] In a first aspect, the present invention provides a conductive carbon concrete base hybrid energy storage and coordinated frequency regulation system, the system comprising: a conductive carbon concrete base power unit, a container lithium battery energy unit and an intelligent coordinated controller, wherein the conductive carbon concrete base power unit and the container lithium battery energy unit are connected in parallel via a common DC bus, and the common DC bus is connected to the grid access point via a bidirectional energy storage converter; The conductive carbon concrete base power unit is connected to a common DC bus via a bidirectional DC converter; the conductive carbon concrete base power unit includes a conductive carbon concrete energy storage body and multiple sets of parallel electrodes embedded in the conductive carbon concrete energy storage body, the electrodes being used to draw out the electrical energy stored in the conductive carbon concrete energy storage body. The containerized lithium battery energy unit includes a lithium battery cluster and a battery management system inside the container. The intelligent collaborative controller is communicatively connected to the battery management system, the bidirectional DC-DC converter, and the bidirectional energy storage converter, respectively. It is used to decompose the received total power command into power components corresponding to different response time scales according to the grid frequency deviation signal, and allocate the instantaneous power component corresponding to the first frequency regulation to the conductive carbon concrete base power unit, and allocate the continuous power component corresponding to the second frequency regulation to the container lithium battery energy unit.

[0007] In a further embodiment, the conductive carbon concrete base power unit is disposed at the bottom of the energy storage container. The conductive carbon concrete base power unit also includes a high insulation isolation layer covering the outer surface of the conductive carbon concrete energy storage body, a static dissipation layer coated on the outer surface of the high insulation isolation layer, and an insulating pad disposed between the conductive carbon concrete energy storage body and the energy storage container. The static dissipation layer is connected to the grounding terminal through a pre-embedded grounding conductor. The high-insulation isolation layer is used to electrically isolate the internally charged conductive carbon concrete energy storage body from the outside, and the electrostatic dissipation layer is used to discharge the static charge accumulated on the surface of the conductive carbon concrete base power unit.

[0008] In a further embodiment, each set of parallel electrodes includes a positive electrode plate and a negative electrode plate. The multiple sets of parallel electrodes are arranged in parallel along the length direction of the conductive carbon concrete energy storage body in an alternating sequence of positive and negative electrodes. The planes of each positive electrode plate and each negative electrode plate are perpendicular to the length direction of the conductive carbon concrete energy storage body.

[0009] In a further implementation scheme, the conductive carbon concrete energy storage body uses cement as the matrix, nano-carbon black as the conductive functional phase, and fine and coarse aggregates as the skeleton, forming a three-dimensional conductive network during the cement hydration process.

[0010] In a further embodiment, the intelligent collaborative controller is equipped with a digital filter; The digital filter is used to decompose the total power command into a high-frequency power component corresponding to the first frequency modulation time scale and a low-frequency power component corresponding to the second frequency modulation time scale. The high-frequency power component is used as the instantaneous power component of the first frequency modulation, and the low-frequency power component is used as the continuous power component of the second frequency modulation. The filter then sends the power command corresponding to the instantaneous power component to the bidirectional DC-DC converter and sends the power command corresponding to the continuous power component to the battery management system.

[0011] In a further implementation scheme, when the grid frequency deviation signal exceeds the preset frequency dead zone and there is an automatic power generation control command for secondary frequency regulation, the intelligent cooperative controller is also used to allocate all the instantaneous power components of the primary frequency regulation to the conductive carbon concrete base power unit for execution, transfer all the power of the automatic power generation control command to the container lithium battery energy unit for execution, and restore the decomposition and allocation of the total power command after the grid frequency deviation signal returns to the preset frequency dead zone and remains stable.

[0012] In a further implementation, the intelligent collaborative controller is also used to monitor the state of charge of the conductive carbon concrete base power unit in real time, and when the state of charge is not in the preset target state of charge range and the system is in a frequency modulation event gap, control the bidirectional DC converter to draw power from the common DC bus to charge the conductive carbon concrete base power unit, so as to restore it to the preset target state of charge range.

[0013] In a further embodiment, the DC output terminal of the container lithium battery energy unit is directly connected to a common DC bus, and the rated voltage of the common DC bus is the same as the rated output voltage of the container lithium battery cluster. The bidirectional DC-DC converter is an isolated bidirectional DC-DC converter. The low-voltage side of the bidirectional DC-DC converter is connected to the electrodes of the conductive carbon concrete base power unit, and the high-voltage side of the bidirectional DC-DC converter is connected to the common DC bus. The bidirectional DC-DC converter operates in boost mode under discharge conditions and in buck mode under charging conditions.

[0014] Secondly, the present invention provides a method for coordinated frequency regulation of hybrid energy storage on a conductive carbon concrete base, using the aforementioned conductive carbon concrete base hybrid energy storage coordinated frequency regulation system. The method includes the following steps: The system monitors the grid frequency deviation signal at the grid access point and the total power command issued by the grid dispatch center in real time, and determines whether the grid frequency deviation signal exceeds the preset frequency dead zone. If the power grid frequency deviation signal exceeds the preset frequency dead zone, it is determined to be a primary frequency modulation event, and the total power command is allocated as the instantaneous power component of the primary frequency modulation to the conductive carbon concrete base power unit to perform instantaneous power response. If the power grid frequency deviation signal does not exceed the preset frequency dead zone, it is determined to be a secondary frequency modulation event. The total power command is decomposed into power components corresponding to different response time scales to obtain the high-frequency power component of the primary frequency modulation time scale and the low-frequency power component of the secondary frequency modulation time scale. The high-frequency power component is allocated to the conductive carbon concrete base power unit for execution, and the low-frequency power component is allocated to the container lithium battery energy unit for execution.

[0015] In a further embodiment, the method further includes: The state of charge of the conductive carbon concrete base power unit is monitored in real time. When the state of charge deviates from the preset target state of charge range and the system is in a frequency modulation event gap, the bidirectional DC converter is controlled to draw power from the common DC bus to charge the conductive carbon concrete base power unit, so that it is restored to the target state of charge range.

[0016] This invention provides a conductive carbon concrete base hybrid energy storage and coordinated frequency regulation system and method. The system includes a conductive carbon concrete base power unit, a containerized lithium battery energy unit, and an intelligent coordinated controller. The conductive carbon concrete base power unit includes a conductive carbon concrete energy storage body and multiple sets of parallel electrodes embedded in the conductive carbon concrete energy storage body. The electrodes are used to extract the electrical energy stored in the conductive carbon concrete energy storage body. The intelligent coordinated controller is used to decompose the received total power command into power components corresponding to different response time scales according to the grid frequency deviation signal, and allocate the instantaneous power component corresponding to the first frequency regulation to the conductive carbon concrete base power unit, and allocate the continuous power component corresponding to the second frequency regulation to the containerized lithium battery energy unit. Compared with existing technologies, this system transforms the original concrete base of the energy storage container into a conductive carbon concrete power storage unit with supercapacitor characteristics. This unit is connected in parallel with the lithium battery energy unit inside the container on the DC side. Through an intelligent collaborative controller, power commands are dynamically distributed to the base and lithium battery according to the response time scale. Without occupying additional space, the base undertakes the task of rapid frequency regulation, while the lithium battery focuses on energy management. This achieves the integration of structural load-bearing and power storage of the concrete base. The base can respond to frequency regulation in milliseconds while avoiding frequent rapid charging and discharging of the lithium battery, thus extending its cycle life. Without increasing the footprint and cost, the system simultaneously improves the frequency regulation response performance, lithium battery cycle life, and overall life cycle economy of the energy storage system. Attached Figure Description

[0017] Figure 1 This is a block diagram of the conductive carbon concrete base hybrid energy storage and coordinated frequency modulation system provided in the embodiments of the present invention; Figure 2 This is a schematic diagram of the overall architecture of the conductive carbon concrete base hybrid energy storage and coordinated frequency regulation system provided in this embodiment of the invention; Figure 3 This is a schematic cross-sectional view of the conductive carbon concrete base power unit structure provided in an embodiment of the present invention; Figure 4 This is a schematic diagram of the collaborative control strategy logic flow provided in an embodiment of the present invention; Figure 5 This is a schematic diagram of the electrical topology of the conductive carbon concrete base hybrid energy storage and coordinated frequency modulation system provided in this embodiment of the invention. Figure 6 This is a schematic diagram of the process of the conductive carbon concrete base hybrid energy storage and coordinated frequency modulation method provided in the embodiment of the present invention.

[0018] Explanation of reference numerals in the attached figures: 101, power unit of conductive carbon concrete base; 102, energy unit of containerized lithium battery; 103, intelligent collaborative controller. Detailed Implementation

[0019] The embodiments of the present invention are described in detail below with reference to the accompanying drawings. The embodiments are given for illustrative purposes only and should not be construed as limiting the present invention. The accompanying drawings are for reference and illustration only and do not constitute a limitation on the scope of patent protection of the present invention, because many changes can be made to the present invention without departing from the spirit and scope of the present invention.

[0020] Figure 1 This is a block diagram of a conductive carbon concrete base hybrid energy storage and coordinated frequency regulation system provided in an embodiment of the present invention. The present invention provides a conductive carbon concrete base hybrid energy storage and coordinated frequency regulation system, such as... Figure 1 As shown, the system includes a conductive carbon concrete base power unit 101, a containerized lithium battery energy unit 102, and an intelligent collaborative controller 103. The conductive carbon concrete base power unit and the containerized lithium battery energy unit are connected in parallel via a common DC bus. The common DC bus is connected to the grid access point via a bidirectional energy storage converter. The DC output terminal of the containerized lithium battery energy unit is directly connected to the common DC bus. The rated voltage of the common DC bus is the same as the rated output voltage of the containerized lithium battery cluster. It should be noted that hybrid energy storage refers to a dual-medium architecture of the conductive carbon concrete base power unit and the containerized lithium battery energy unit.

[0021] In some embodiments, the conductive carbon concrete base power unit is connected to a common DC bus via a bidirectional DC-DC converter. The conductive carbon concrete base power unit includes a conductive carbon concrete energy storage body and multiple sets of parallel electrodes embedded within the conductive carbon concrete energy storage body. These electrodes are used to extract the electrical energy stored in the conductive carbon concrete energy storage body. The bidirectional DC-DC converter is an isolated bidirectional DC-DC converter. The low-voltage side of the bidirectional DC-DC converter is connected to the electrodes of the conductive carbon concrete base power unit, and the high-voltage side of the bidirectional DC-DC converter is connected to the common DC bus. The device operates in boost mode during discharge and buck mode during charging. In this embodiment, the conductive carbon concrete base power unit is located at the bottom of a 20-foot standard lithium battery energy storage container. It transforms the ordinary concrete base, which was originally only used to support the weight of the container, into an energy storage base made of conductive carbon concrete with fast charging and discharging characteristics similar to a supercapacitor. This allows it to both support the mechanical load of the upper container and serve as an energy storage component that undertakes the task of fast power response. It also adopts a hybrid energy storage system composed of a power-type conductive carbon concrete base and an energy-type lithium battery.

[0022] Figure 2 This is a schematic diagram of the overall architecture of the conductive carbon concrete base hybrid energy storage and coordinated frequency regulation system provided in this embodiment of the invention. The conductive carbon concrete base power unit is the power-type energy storage unit in the entire conductive carbon concrete base hybrid energy storage and coordinated frequency regulation system. It is primarily responsible for providing the second-level instantaneous power support required for primary frequency regulation of the power grid, and also assists in the initial fast power portion of secondary frequency regulation. This conductive carbon concrete base power unit is electrically connected in parallel with the lithium battery energy unit inside the container, and they cooperate in control, jointly connected to the grid access point. After the conductive carbon concrete base power unit undertakes the fast frequency regulation task, the lithium battery energy unit is freed up to perform demand regulation. The continuous energy support for energy time shifting and secondary frequency regulation allows it to leverage its high energy density advantage. According to the general requirements of primary frequency regulation of the power grid, the target output power of the conductive carbon concrete base power unit is determined according to 5% to 10% of the rated power of the energy storage container. Taking an energy storage container with a rated power of 500 kW as an example, the target output power of the conductive carbon concrete base power unit is 50 kW. At the same time, in order to meet the requirement that primary frequency regulation events usually last for 10 to 30 seconds, the conductive carbon concrete base power unit is designed to be able to independently support a 50 kW discharge for at least 30 seconds. In addition, it is also necessary to provide an initial power buffer of 5 to 10 minutes for secondary frequency regulation.

[0023] In some embodiments, the conductive carbon concrete energy storage body uses cement as the matrix, nano-carbon black as the conductive functional phase, and fine and coarse aggregates as the skeleton, forming a three-dimensional conductive network during cement hydration. In a specific embodiment, the conductive carbon concrete energy storage body of the conductive carbon concrete base power unit is cast from conductive carbon concrete material. This conductive carbon concrete material uses cement as the structural matrix, nano-carbon black as the core conductive phase, and is mixed with fine aggregate (sand), coarse aggregate (stone), water, and additives in a specific ratio. For example, the usage per cubic meter and the total usage of each component are as follows: cement usage per cubic meter is 456 kg, and the total usage is 2508 kg; nano-carbon black... The dosage of carbon black is 36.5 kg per cubic meter, with a total dosage of 200.8 kg. The nano-carbon black disperses in the cement matrix to form a conductive network. The dosage of fine aggregate (sand) is 1368 kg per cubic meter, with a total dosage of 7524 kg. The dosage of coarse aggregate (stone) is 270 kg per cubic meter, with a total dosage of 1485 kg. The dosage of water is 250.8 kg per cubic meter, with a total dosage of 1379.4 kg, resulting in a water-cement ratio of approximately 0.55. The dosage of additives (dispersants, etc.) is 21.9 kg per cubic meter, with a total dosage of 120.5 kg, used to ensure uniform dispersion of carbon black in the slurry. It should be noted that this conductive carbon concrete material belongs to the category of electronically conductive carbon concrete. Carbon Concrete (EC³) is a multifunctional cement-based composite material that combines mechanical strength with electrochemical energy storage capabilities. The energy storage mechanism of conductive carbon concrete is double-layer charge storage, which means that charge is stored physically at the electrode-electrolyte interface without involving electrochemical reactions. This material has supercapacitor characteristics, with a power density of 10 to 15 kW / m³, an energy density of about 2 kWh / m³, and a cycle life of up to one million cycles.

[0024] In this embodiment, to meet the requirements of structural load-bearing capacity and energy storage volume, the conductive carbon concrete energy storage body is preferably designed as a cuboid structure. The outer dimensions of the conductive carbon concrete energy storage body are 6.2 meters long, 2.5 meters wide, and 0.4 meters thick. These dimensions match the bottom installation dimensions of a 20-foot standard energy storage container to meet the structural load-bearing requirements. The outer dimensions of the conductive carbon concrete energy storage body must first match the bottom installation dimensions of the container and the structural load-bearing specifications. The energy storage function is optimized within the structural constraints. After deducting the space occupied by internal electrodes, insulation layers, etc., the net dimensions of the conductive carbon concrete energy storage body are 6.0 meters long, 2.4 meters wide, and 0.38 meters high, with a net volume of approximately 5.5 cubic meters.

[0025] Multiple sets of parallel electrodes are embedded inside the conductive carbon concrete energy storage body to increase the effective working surface area of ​​the electrodes and shorten the charge migration path, thereby reducing the overall equivalent series resistance. To meet the electrical requirements of high power output, in some embodiments, each set of parallel electrodes includes a positive electrode plate and a negative electrode plate. The multiple sets of parallel electrodes are arranged in parallel along the length direction of the conductive carbon concrete energy storage body in an alternating positive and negative electrode sequence. The planes of each positive electrode plate and each negative electrode plate are perpendicular to the length direction of the conductive carbon concrete energy storage body. This embodiment takes a set of multiple sets of parallel electrodes consisting of 4 sets of positive electrode plates and 4 sets of negative electrode plates, for a total of 8 sets of electrode plates, as an example. Each electrode plate is made of 316L stainless steel perforated mesh with a thickness of 1.5 mm and an opening rate of not less than 40%. The geometric dimensions of a single electrode plate are 2.35 meters wide and 0.35 meters high. The effective working surface area of ​​a single electrode plate (both sides are immersed in conductive carbon concrete) is approximately 1.645 square meters. The total effective working surface area of ​​the 4 sets of electrode plates of the same polarity is approximately 6.58 square meters. All electrode plate surfaces are sandblasted to roughen them, thereby enhancing the mechanical interlocking and electrical contact with the conductive carbon concrete, reducing contact resistance while ensuring structural integrity.

[0026] In this embodiment, the electrode plates are arranged vertically and parallel to each other along the length of the conductive carbon concrete energy storage body. The plane of the electrode plate is perpendicular to the length of the conductive carbon concrete energy storage body. The width of the electrode plate extends along the width of the conductive carbon concrete energy storage body, and the height extends along the height of the conductive carbon concrete energy storage body, so that the entire electrode plate is completely immersed in the conductive carbon concrete energy storage body. The eight sets of electrode plates are arranged alternately in the order of positive electrode, negative electrode, positive electrode, and negative electrode. The center-to-center distance between two adjacent electrode plates of the same polarity is 1.5 meters. Due to the staggered arrangement of positive and negative electrode plates, the center-to-center distance between adjacent positive and negative electrode plates is 0.75 meters. After deducting the electrode plate thickness, The net thickness of the conductive carbon concrete dielectric between the different electrode plates is approximately 1.498 meters, which is the effective path length for capacitor charge migration. The distance between the first and last electrode plates and the end of the conductive carbon concrete energy storage body is 0.375 meters. The minimum distance between each electrode plate and the side and upper and lower surfaces of the base is not less than 15 millimeters to meet the requirements of insulation safety and structural protection layer. The electrode plates are positioned in the casting mold by insulating fixing brackets. During construction, the positional accuracy is maintained within ±5 millimeters. The planes of each electrode plate are parallel to each other and the spacing is uniform to ensure that the current field distribution inside the concrete is uniform and to avoid excessive local current density, which can lead to heating and increased internal resistance.

[0027] In this embodiment, the equivalent series resistance of the conductive carbon concrete is mainly determined by the bulk resistance, satisfying the relationship that the equivalent series resistance is directly proportional to the product of the material's bulk resistivity and the electrode spacing, and inversely proportional to the total surface area of ​​the electrodes. This embodiment expands the total surface area by connecting 8 sets of electrodes in parallel and controls the same electrode spacing of 1.5 meters to shorten the charge migration path. Both of these measures together achieve the goal of low equivalent series resistance. In addition, the current collection of the electrodes adopts a three-stage path: single-plate multi-point lead-out, same-polarity parallel current collection, and total cable connection to the converter. The first stage is the single-plate lead-out stage, where 3 resistant rods are uniformly welded along the width direction on the upper edge of each electrode plate. Alkali-based soft copper stranded wire serves as the current lead for each single plate, with a cross-sectional area of ​​35 square millimeters. Multiple leads can balance the current distribution across the plates and prevent current concentration at the edges. The second stage is a same-polarity bus stage, where all leads from the four positive plates are connected in parallel to the positive main busbar, and all leads from the four negative plates are connected in parallel to the negative main busbar. The busbars are located in the electrical compartment at the end of the base and are fully insulated. The third stage is the total output stage, where the positive and negative main buses are each connected to the input terminals of the bidirectional DC-DC converter in the electrical compartment via a flame-retardant power cable, completing the total electrical output of the base power unit.

[0028] In some embodiments, the conductive carbon concrete base power unit is disposed at the bottom of the energy storage container. The conductive carbon concrete base power unit further includes a high-insulation isolation layer covering the outer surface of the conductive carbon concrete energy storage body, a static dissipation layer coated on the outer surface of the high-insulation isolation layer, and an insulating pad disposed between the conductive carbon concrete energy storage body and the energy storage container. The static dissipation layer is connected to a grounding terminal through a pre-embedded grounding conductor. The high-insulation isolation layer is used to electrically isolate the internally charged conductive carbon concrete energy storage body from the outside. The static dissipation layer is used to discharge the static charge accumulated on the surface of the conductive carbon concrete base power unit. The insulating pad is used to transfer the mechanical load of the container to the base, while realizing electrical isolation between the container and the charged base.

[0029] In a specific embodiment, Figure 3This is a cross-sectional schematic diagram of the conductive carbon concrete base power unit structure provided in an embodiment of the present invention. The conductive carbon concrete base power unit is composed of multiple layers, including a conductive carbon concrete energy storage main body layer, a high insulation isolation layer, and a surface electrostatic dissipation layer, arranged sequentially from bottom to top (from inside to outside). The conductive carbon concrete energy storage main body layer is the core energy storage part of the base, cast from the aforementioned conductive carbon concrete material, with an embedded electrode system. The internal high insulation isolation layer is located between the conductive carbon concrete energy storage main body and the outer surface of the base. It is a continuous and dense insulating coating, applied using solvent-free epoxy glass flake coating via high-pressure airless spraying in three coats, with a total dry film thickness of not less than 2 mm. The insulation layer, with a withstand voltage greater than 15 kV, ensures electrical isolation between the conductive carbon concrete energy storage body and the ground and external environment. After construction, a comprehensive inspection is conducted using an electric spark leak detector to ensure the coating is continuous and free of pinholes. The detection voltage of the electric spark leak detector is 15 kV. A surface conductive dissipative layer is placed on top of the high-insulation isolation layer. This surface conductive dissipative layer is the outermost layer of the base and is formed by scraping with conductive epoxy mortar mixed with conductive mica powder, with a thickness of approximately 5 mm. During construction, copper foil grounding strips are pre-embedded, one every 2 meters. After this layer cures, its surface resistance is measured using a resistance tester. By adjusting the amount of conductive filler, the surface resistance value is ensured to be stable at 10 ohms. 5 Up to 10 7 Between ohms, all grounding copper foils are reliably connected to the reserved grounding terminal. This electrostatic dissipation layer is used to safely discharge the static charge accumulated on the base surface to the ground, preventing safety hazards caused by static accumulation.

[0030] The electrical compartment is located at the end of the conductive carbon concrete energy storage body. This compartment is waterproof and explosion-proof. It houses a bidirectional DC-DC converter and a capacitor management system. The bidirectional DC-DC converter has an input voltage range of 0 to 60 volts DC and a rated output voltage of 400 volts DC, matching the voltage of the common DC bus. The converter has a continuous power capability of at least 60 kilowatts and a peak power capability of at least 100 kilowatts for 10 seconds. This bidirectional DC-DC converter is used to connect the base to the common DC bus. The system features voltage matching and bidirectional power transmission. During discharge, it operates in boost mode, raising the 48V base voltage to the 400V DC bus voltage. During charging, it operates in buck mode, drawing power from the high-voltage DC bus and stepping it down to charge the base. The voltage and temperature sensing lines of the capacitor management system are connected to the voltage and temperature sensors pre-embedded in the base, respectively. Three temperature sensors are evenly distributed along the length of the base to collect the base's terminal voltage, charging and discharging current, and body temperature, and to monitor the voltage consistency of each group of electrodes. When the voltage difference between groups exceeds 0.5V, passive equalization correction is triggered.

[0031] In this embodiment, the energy storage capacity of the conductive carbon concrete base power unit is equal to the net volume of the conductive carbon concrete energy storage body multiplied by the material's energy density. The net volume of the conductive carbon concrete base power unit is 5.5 cubic meters, and the energy density is 2 kWh / m³, resulting in a calculated energy storage capacity of 11 kWh. The target power to be provided by the conductive carbon concrete base power unit is 50 kW. The required power density is equal to the total power divided by the volume, i.e., 50 kW divided by 5.5 cubic meters, approximately 9.1 kW / m³. This value is within the theoretical range of the material's power density (10 to 15 kW / m³), therefore the power output requirement can be met. In a single-frequency modulation scenario, this embodiment can support a 50 kW power discharge with 11 kWh of energy. The time is equal to the energy storage capacity divided by the power, that is, 11 kWh divided by 50 kW, which equals 0.22 hours, or 13.2 minutes. This time is far longer than the 30 seconds required for a first-order frequency regulation and can even cover the initial stage of most second-order frequency regulation events. Among them, the equivalent series internal resistance of the material is a key parameter affecting the power output. According to the maximum power transfer theorem, the maximum output power is approximately equal to the square of the operating voltage divided by 4 times the equivalent series internal resistance. If the operating voltage is 48 volts and the maximum output power is required to be greater than 50 kW, then the equivalent series internal resistance must be less than the square of 48 divided by (4 multiplied by 50000), that is, less than 0.01152 ohms. This requires the material to have extremely low volume resistivity, which can be achieved through engineering means such as multiple sets of electrodes in parallel and optimized electrode arrangement.

[0032] The target power of the base is determined based on the grid frequency regulation requirements. In this embodiment, the boundary parameters are first clarified. According to the frequency regulation rules of the project connected to the grid, the maximum output ratio of primary frequency regulation, response time requirements, minimum duration, and the rate of change and peak requirements of the automatic generation control (AGC) command for secondary frequency regulation are determined. It should be noted that the maximum output of primary frequency regulation of the energy storage power station is 5% to 10% of the rated power, the response time is no more than 1 second, and the continuous discharge time is no less than 30 seconds. The target output power of the base is equal to the rated active power of the container multiplied by the frequency regulation power ratio coefficient. The frequency regulation power ratio coefficient is 5% to 10%, 5% to 8% when only undertaking primary frequency regulation, and 8% to 10% when undertaking the initial power of secondary frequency regulation.

[0033] In this embodiment, the base volume is primarily constrained by power density, while energy density is only used for duration verification. The minimum volume required to meet power requirements is equal to the target output power of the base divided by the material power density; the lower limit is used in engineering design to allow for margin. The minimum energy required for the shortest continuous discharge required for frequency modulation is equal to the target output power of the base multiplied by the shortest continuous discharge time required for frequency modulation. The minimum volume required to meet energy requirements is equal to the minimum required energy divided by the material energy density. The final theoretical minimum volume is the larger of the two values. Actual design requires an additional 10% to 15% engineering margin on top of the theoretical minimum volume, deducting the volume occupied by electrodes and insulation layers, while simultaneously meeting the minimum structural load-bearing requirements. This determines the actual pouring volume of the conductive carbon concrete. This embodiment also provides the preparation and construction process of the conductive carbon concrete base power unit, as shown in the following flowchart: Material preparation and mold preparation: In this embodiment, materials are prepared according to the above proportions, and a sturdy casting mold is prepared. A 0.5 mm thick flexible F46 fluoroplastic film is pre-laid on the bottom and side walls of the mold. This film will serve as the bottom layer of the internal high insulation isolation layer to ensure that the concrete body is insulated from the ground after molding. The position of the electrode plate is precisely fixed in the mold to ensure that the positive and negative electrode plates are arranged in parallel and staggered. The electrode leads are led out from the predetermined sealing sleeve at one end of the mold.

[0034] Conductive carbon concrete mixing: This embodiment adopts an improved two-stage mixing method to ensure uniform dispersion of carbon black. Specifically, this embodiment first performs dry premixing by putting cement, premixed carbon black, dispersant powder, and fine aggregate into a forced mixer and dry mixing for 3 to 5 minutes until the color is uniform. Then, it performs initial wet mixing by adding about 70% of an aqueous solution containing the dispersant and stirring for 5 to 8 minutes to form a uniform conductive slurry. Finally, it performs final mixing by adding coarse aggregate, the remaining water, and water-reducing agent solution and continuing to stir for 3 to 5 minutes until a conductive concrete mixture with good workability is obtained.

[0035] Layered pouring and vibration: In this embodiment, the conductive concrete mixture is poured into the mold in three layers. After each layer is poured, a high-frequency vibrator is immediately inserted for full vibration. Special attention is paid to the vibration around and below the electrode plate to ensure that the concrete densely covers the electrode and eliminates voids. Avoid touching the electrode plate and insulating film during vibration.

[0036] Curing: After pouring, cover with plastic film and cure in a standard wet environment of 20±5 degrees Celsius for 28 days.

[0037] Insulation protection layer construction: After curing, demolding is carried out, all exposed concrete surfaces of the base are ground and cleaned, and solvent-free epoxy glass flake coating is applied by high-pressure airless spraying in three coats. The total dry film thickness is not less than 2 mm. Each coat is inspected after application, and the final layer is fully tested with an electric spark leak detector to ensure that the coating is continuous and free of pinholes.

[0038] Construction of the static dissipation layer: Apply a 5mm thick layer of static-dissipating epoxy mortar mixed with conductive mica powder onto the insulation layer. During construction, embed a copper foil grounding strip every 2 meters. After the layer cures, measure its surface resistance using a resistance tester. Adjust the amount of conductive filler to ensure the surface resistance value remains stable at 10 ohms. 5 Up to 10 7 Between ohms. Reliably connect all grounding copper foils to the reserved grounding terminals.

[0039] Electrical equipment installation: Install a bidirectional DC-DC converter and a capacitor management system in the waterproof and explosion-proof electrical compartment at the end of the base. Connect the four sets of positive leads from the base in parallel to the positive input terminal of the bidirectional DC-DC converter, and connect the four sets of negative leads in parallel to the negative input terminal. Apply conductive paste to the connection points and apply the specified torque. Connect the voltage and temperature sensing wires of the capacitor management system to the sensors pre-embedded in the base. Connect the output terminal of the bidirectional DC-DC converter to the common DC bus.

[0040] Because the conductive carbon concrete base power unit has supercapacitor characteristics, its energy storage mechanism is the double-layer charge storage at the electrode-electrolyte interface, without electrochemical reaction processes. It boasts advantages such as high power density, fast response speed, and long cycle life. Therefore, in this embodiment, the conductive carbon concrete base power unit is used to handle the instantaneous high-power output required for primary frequency regulation of the power grid, as well as the rapid power response during the initial stage of secondary frequency regulation. In primary frequency regulation events, the base power unit outputs the target power within milliseconds. In secondary frequency regulation, the base power unit handles the rapid changes in the initial command. During the intervals between frequency regulation events, the base power unit draws power from the common DC bus via a bidirectional DC-DC converter to recharge itself, restoring its State of Charge (SOC) to the target range of 55% to 70%. The formula for calculating the State of Charge is: In the formula, SOC is the state of charge; U is the current terminal voltage; This is the highest operating voltage; The minimum discharge cutoff voltage is 24 volts, with the maximum operating voltage being 52 volts. The terminal voltage corresponding to the target operating state of charge range of 55% to 70% is approximately 39.6 volts to 44.8 volts.

[0041] In this embodiment, the state of charge (SOC) measurement employs a combined method, primarily based on terminal voltage mapping, supplemented by coulomb integration, and supplemented by temperature correction compensation. This method is executed by the capacitor management system. Specifically, this embodiment utilizes the monotonic correspondence between SOC and terminal voltage to directly calculate the SOC through voltage acquisition. When the base is in a static state without charging or discharging current (static time greater than or equal to 30 seconds), the terminal voltage is the open-circuit voltage. The capacitor management system directly acquires the terminal voltages of both the positive and negative terminals and substitutes them into the aforementioned SOC calculation formula to obtain a high-precision SOC value with a measurement error less than [value missing]. At 1%, when the base is in charging or discharging condition, the terminal voltage will drop or rise due to the equivalent series internal resistance, which cannot directly represent the true state of charge. At this time, the capacitor management system synchronously collects the real-time terminal voltage and charging / discharging current of the base at a frequency of 1 kHz. Based on the pre-calibrated equivalent series internal resistance, the internal resistance voltage drop is calculated. This internal resistance voltage drop is equal to the real-time current multiplied by the equivalent series internal resistance. In the discharging condition, the corrected equivalent open-circuit voltage is equal to the real-time terminal voltage plus the internal resistance voltage drop; in the charging condition, the opposite is true. Substituting the corrected equivalent open-circuit voltage into the state of charge formula, the real-time state of charge can be calculated.

[0042] To eliminate accumulated errors during long-term operation, this embodiment introduces the Coulomb integration method for periodic dynamic calibration. The capacitor management system collects the charging and discharging current in real time and integrates it over time to calculate the amount of charge charged or discharged, converting it into energy change, and dynamically recursively predicting the state of charge. Every hour, or after each frequency modulation event ends and the system enters a static state, the precise state of charge value obtained by the open-circuit voltage method is used to reset and correct the Coulomb integration result. In addition, this embodiment introduces a temperature compensation correction mechanism. The equivalent capacitance and internal resistance of the conductive carbon concrete will change with the ambient temperature. The capacitor management system has three temperature sensors pre-embedded inside the base to collect the real-time temperature of the concrete body and introduces a temperature correction coefficient. The formula for calculating the state of charge after temperature correction is as follows: In the formula, This is the temperature-corrected state of charge; This is a temperature correction factor; The current temperature; The reference temperature is 25 degrees Celsius.

[0043] The bidirectional DC-DC converter matched with the power unit of the conductive carbon concrete base has three operating modes: a standby mode, a discharge mode and a charge mode. All mode switching is driven by a power command issued by an upper-layer intelligent cooperative controller, and a local controller of the converter independently completes smooth switching. Specifically, in the standby mode, the power command is 0, all power switching tubes are locked, no power is transmitted in the converter, and only the connection between the low-voltage side and the high-voltage side is maintained for standby to wait for a frequency modulation command; in the discharge mode (boost mode), through a forward power command, the base releases energy to the high-voltage DC bus, corresponding to the scenarios of primary frequency modulation output and secondary frequency modulation initial power support. At this time, the bidirectional DC-DC converter operates in the boost mode to boost the low-voltage direct current of the base to the voltage of the common DC bus; in the charge mode (buck mode), through a negative power command, the high-voltage DC bus recharges energy to the base, corresponding to the scenarios of state of charge restoration and energy supplement during the frequency modulation interval. At this time, the bidirectional DC-DC converter operates in the buck mode, takes power from the common DC bus and steps down the power to charge the base.

[0044] In this embodiment, the bidirectional DC-DC converter adopts a unified dual closed-loop control architecture with a current inner loop and a power outer loop, so as to realize dead-zone-free smooth switching between the boost mode and the buck mode. The local controller receives a target power command issued by the intelligent cooperative controller in real time, and converts the target power command into a primary-side target current according to the current base-side voltage. It is defined that current flowing out of the base is discharging (positive direction), and current flowing into the base is charging (negative direction). When the polarity of the target current changes, the controller continuously adjusts the duty ratio of the switching tube to automatically transition between the boost working area and the buck working area, without mode switching breakpoints and dead zones. A current change rate limit is added during the switching process, and the current change rate does not exceed 20% / ms of the rated value during normal switching, so as to prevent bus voltage fluctuation and device stress impact caused by sudden current change. The forward discharge command for primary frequency modulation has the highest interrupt priority, which can directly interrupt the ongoing charging process and quickly switch to the discharge mode, so as to ensure the frequency modulation response speed. A typical switching sequence is that the total response time for switching from the standby mode to the discharge mode is less than or equal to 25 milliseconds; the switching from the discharge mode to the charge mode adopts ramp-type smooth switching, and the voltage fluctuation of the DC bus throughout the process is less than or equal to ±1%.

[0045] In summary, the existing concrete base of energy storage containers is merely a passive load-bearing structure, used only to support the container body. It occupies a large area but has no energy storage function. Although existing hybrid energy storage systems also combine lithium batteries with supercapacitors, supercapacitors are usually arranged in separate prefabricated compartments, requiring additional land and construction costs. In this embodiment, the conductive carbon concrete base power unit is directly set at the bottom of the energy storage container, transforming the originally non-functional concrete base into a component that can store electrical energy and participate in grid frequency regulation. There is no need to occupy additional space to configure independent power-type energy storage equipment, realizing the combination of structural load-bearing and electrical energy storage, reducing the overall system cost. At the same time, this embodiment increases the electrode surface area and reduces the equivalent series internal resistance through the design of multiple sets of parallel electrodes, enabling the base to meet the electrical requirements of high power output. Furthermore, the double-layer design of the internal high insulation isolation layer and the surface electrostatic dissipation layer solves the electrical safety problem of the charged concrete base in the field application of engineering projects.

[0046] As an energy storage unit in a hybrid energy storage system, the containerized lithium battery energy unit primarily undertakes functions such as demand regulation, energy time shifting, and continuous energy support for secondary frequency regulation. Leveraging the high energy density of lithium batteries, this unit is suitable for long-duration charge-discharge scenarios, while rapid instantaneous power response is handled by the conductive carbon concrete base power unit. During primary frequency regulation events, the lithium battery energy unit remains inactive or performs only minor compensation. During secondary frequency regulation, the lithium battery energy unit handles the low-frequency component obtained after high-low frequency decomposition, representing the slowly changing, long-duration power command. When primary and secondary frequency regulation occur simultaneously, if the entire power capacity of the base unit is occupied by the primary frequency regulation command, the full power of the original secondary frequency regulation command (including the high-frequency component that should have been handled by the base unit) is smoothly transferred to the lithium battery energy unit. The lithium battery tracks the command at its maximum response rate, ensuring no shortfall in the system's total output power. In demand regulation and energy dispatch scenarios, since these commands are slow, planned charge-discharge commands, they are all executed by the lithium battery energy unit.

[0047] In some embodiments, the containerized lithium battery energy unit is located inside the energy storage container. The containerized lithium battery energy unit includes lithium battery clusters and a battery management system. Each lithium battery cluster consists of multiple lithium battery cells connected in series or parallel. Its rated output voltage matches the voltage level of the common DC bus, typically 800 volts or 1500 volts high voltage level. After being combined by a DC combiner cabinet, each lithium battery cluster is directly connected to the common DC bus through DC protection devices such as DC circuit breakers and fuses, without adding any additional DC / DC conversion links. In other embodiments, the supporting equipment of the containerized lithium battery energy unit also includes a DC combiner cabinet and DC protection devices. The DC combiner cabinet is used to combine the DC outputs of multiple lithium battery clusters into a single total output. The DC combiner cabinet is equipped with busbars and connection terminals. The DC protection devices include DC circuit breakers and fuses. The DC protection devices are installed on the output branches of each lithium battery cluster and the total output branch, and are used to achieve overcurrent protection, short circuit protection, and fault isolation.

[0048] In this embodiment, the containerized lithium battery energy unit is directly connected to the common DC bus and connected in parallel on the DC side with the conductive carbon concrete base power unit. Specifically, the output of each lithium battery cluster is directly connected to the common DC bus after passing through a DC combiner cabinet and DC protection devices. Since the rated output voltage of the lithium battery cluster matches the voltage level of the common DC bus, this embodiment does not require an additional DC-DC converter for voltage conversion, so that the lithium battery is the main energy source of the system, with a large charging and discharging throughput. Omitting a power conversion stage can reduce the operating loss throughout the entire life cycle, which is in line with its large capacity and long-term charging and discharging characteristics. It should be noted that the conductive carbon concrete base power unit is connected to the same common DC bus through a bidirectional DC-DC converter. This bidirectional DC-DC converter is responsible for converting the low voltage (48 volts) of the base unit to the same level (800 volts or 1500 volts) as the common DC bus voltage. The common DC bus is connected to the grid access point through a bidirectional energy storage converter to complete the DC-AC conversion and grid connection control.

[0049] In this embodiment, the battery management system (BMS) is communicatively connected to each lithium battery cluster. The BMS collects state parameters such as voltage, current, and temperature of each cell, monitors the state of charge (SOC) and state of health (SOH) of the lithium batteries, and connects to the Intelligent Coordination Controller (ICC) via a communication network to receive power commands and provide feedback on operating status information. The ICC connects to the BMS of the lithium battery energy unit and the bidirectional energy storage converter via a communication network, which can be an Ethernet or a controller area network. The ICC collects the SOC, SOH, and operating parameters of the lithium battery units in real time and sends power commands to the BMS according to a preset strategy. After receiving the power commands, the BMS performs internal power allocation based on the state of each lithium battery cluster and controls the charging and discharging process of each cluster.

[0050] It should be noted that the rated power and energy storage capacity of the lithium battery energy unit are determined according to the overall design of the energy storage power station. The primary frequency regulation of the power grid requires the energy storage equipment to respond to frequency fluctuations within a few seconds and provide short-term high-power support. This part is undertaken by the conductive carbon concrete base power unit. The secondary frequency regulation requires a duration of several minutes to tens of minutes, which requires a certain energy continuity capability. This part is undertaken by the lithium battery energy unit. Demand regulation and energy time shift scenarios are mainly based on energy throughput, which are also undertaken by the lithium battery energy unit. In the secondary frequency regulation process, the intelligent collaborative controller performs real-time filtering and decomposition on the received automatic generation control power command. The fluctuation part above the cutoff frequency is identified as high-frequency component and allocated to the base power unit. In this embodiment, the cutoff frequency is taken as 0.05 Hz. The part below the cutoff frequency is identified as low-frequency component and allocated to the lithium battery energy unit. The sum of the high-frequency component and the low-frequency component equals the total power command of the automatic generation control, ensuring that the total output of the system accurately tracks the scheduling requirements.

[0051] In summary, existing energy storage containers are equipped with only a single lithium battery energy storage system. The lithium battery must undertake both the rapid power response for primary frequency regulation and the energy support and demand regulation tasks for secondary frequency regulation. Due to the limitations of the electrochemical reaction rate and the adjustment speed of the battery management system, the response time of the lithium battery is usually over hundreds of milliseconds, making it difficult to achieve the optimal rapid frequency support effect. If the lithium battery is forced to frequently undergo rapid, shallow charging and discharging to meet the primary frequency regulation requirements, it will severely exacerbate the cyclic degradation of its cells, sacrificing its core lifespan and economy for energy time shifting (demand regulation). Therefore, this embodiment sets up the container lithium battery energy unit to work in conjunction with the conductive carbon concrete base power unit, freeing the lithium battery from the frequent rapid charging and discharging tasks. It can then only undertake the slow-changing low-frequency power commands and long-term energy throughput tasks, thereby effectively reducing the cyclic degradation of the lithium battery, extending the overall lifespan of the energy storage system, and improving the economic efficiency throughout the entire life cycle. At the same time, since the lithium battery energy unit is directly connected to the common DC bus, the power conversion links are reduced, further reducing energy loss during long-term energy throughput.

[0052] In some embodiments, the intelligent cooperative controller is communicatively connected to the battery management system, the bidirectional DC-DC converter, and the bidirectional energy storage converter, respectively. It is used to decompose the received total power command into power components corresponding to different response time scales based on the grid frequency deviation signal. The instantaneous power component corresponding to primary frequency modulation is allocated to the conductive carbon concrete base power unit, and the continuous power component corresponding to secondary frequency modulation is allocated to the containerized lithium battery energy unit. Specifically, the intelligent cooperative controller is equipped with a digital filter; the digital filter is used to decompose the total power command into a high-frequency power component corresponding to the primary frequency modulation time scale and a low-frequency power component corresponding to the secondary frequency modulation time scale, using the high-frequency power component as the primary frequency modulation... The system uses the instantaneous power component of the primary frequency modulation (PFEM) as the continuous power component of the secondary frequency modulation (PFEM), and sends the power command corresponding to the instantaneous power component to the bidirectional DC-DC converter and the power command corresponding to the continuous power component to the battery management system. When the grid frequency deviation signal exceeds the preset frequency dead zone and there is an automatic generation control power command for secondary frequency modulation, the intelligent cooperative controller is also used to allocate all the instantaneous power component of the primary frequency modulation to the conductive carbon concrete base power unit for execution, transfer all the power of the automatic generation control power command to the container lithium battery energy unit for execution, and restore the decomposition and allocation of the total power command after the grid frequency deviation signal returns to the preset frequency dead zone and remains stable.

[0053] In a specific embodiment, Figure 4This is a schematic diagram of the collaborative control strategy logic flow provided in this embodiment of the invention. The Intelligent Coordination Controller (ICC) uses an industrial-grade controller as its hardware platform. The ICC is connected to the bidirectional DC-DC converter on the power unit side of the base unit via a communication network to issue power commands and receive operating status feedback signals from the converter. The ICC is also connected to the battery management system of the lithium battery energy unit to issue power commands and receive operating parameters such as the state of charge and health status of the lithium battery. Furthermore, the ICC is connected to the bidirectional energy storage converter to issue grid-connected power commands and receive the operating status of the converter. Finally, the ICC is connected to the grid dispatching system to receive automatic generation control commands and primary frequency regulation signals. In this embodiment, the ICC also has an analog signal acquisition channel, which is used to acquire in real time the common DC bus voltage, base unit branch current, lithium battery unit branch current, and the grid frequency signal at the point of common coupling (PCC). Figure 5 This is a schematic diagram of the electrical topology of the conductive carbon concrete base hybrid energy storage and coordinated frequency modulation system provided in this embodiment of the invention.

[0054] The intelligent collaborative controller, acting as the system's control hub, synchronously samples the grid frequency f and the automatic generation control power command Pc at a 1-millisecond cycle. It analyzes the grid frequency signal and the automatic generation control power command, and dynamically allocates the power command to the conductive carbon concrete base power unit and the containerized lithium battery energy unit according to a preset strategy. The intelligent collaborative controller's processing logic consists of two independent channels operating in parallel: the first channel is a frequency deviation detection channel, which synchronously samples the grid frequency at the grid connection point at a 1-millisecond cycle and calculates the frequency deviation value in real time. The frequency deviation value is the difference between the actual grid frequency and the rated frequency. When the absolute value of the frequency deviation exceeds the preset dead zone, it is determined that a frequency regulation event has been triggered. The second channel is a dispatch command receiving channel, which receives the automatic generation control (AGC) power command issued by the grid dispatch system in real time. This command is a numerical power target value. The two control channels operate independently and there is no mutual exclusion or shielding relationship.

[0055] For the primary frequency regulation control process, when the intelligent co-controller detects that the absolute value of the frequency deviation exceeds the dead zone, it determines that a primary frequency regulation event has been triggered. For example, when the absolute value of the frequency deviation is greater than 0.03 Hz or less than -0.03 Hz, it is determined that a primary frequency regulation event has been triggered. At this time, the intelligent co-controller immediately calculates the primary frequency regulation target power according to the droop characteristic curve PF-droop. The primary frequency regulation target power is the product of the droop coefficient and the frequency deviation. The droop characteristic curve shows a linear relationship, where the primary frequency regulation target power equals the negative droop coefficient multiplied by the frequency deviation. The droop coefficient is preset according to the rated power of the energy storage container and the grid frequency regulation rules. This embodiment does not impose any restrictions. After calculating the primary frequency regulation target power, the intelligent co-controller... Instantly, the calculated primary frequency modulation target power is fully allocated to the bidirectional DC-DC converter of the base power unit. The base power command is set to be equal to the primary frequency modulation target power. At the same time, the power command of the lithium battery energy unit is set to zero or only slightly compensated and sent to the battery management system of the lithium battery energy unit, so that the lithium battery energy unit maintains its current power output state. This allocation method uses the millisecond-level response speed of the base power unit to withstand instantaneous power surges and avoids the lithium battery from aging faster due to frequent and rapid charging and discharging. In this embodiment, the exit condition of the primary frequency modulation event is that after the frequency deviation falls back to the dead zone range and remains stable for no less than 1 second, the primary frequency modulation event is determined to be over, and the intelligent cooperative controller automatically resumes the normal secondary frequency modulation cooperative mode.

[0056] When the grid connection point frequency is within the dead zone and no primary frequency regulation event is triggered, if the intelligent cooperative controller receives an automatic generation control power command from the power grid dispatch center, it will initiate secondary frequency regulation control. The intelligent cooperative controller uses a second-order Butterworth digital filter to perform real-time filtering and decomposition of the automatic generation control power command, separating it into high-frequency power components and low-frequency power components. The specific execution steps are as follows: In this embodiment, the automatic generation control power command is input to a high-pass filter and a low-pass filter with a cutoff frequency of 0.05 Hz. The high-frequency power component output from the high-pass filter is used as the target power command for the base power unit, and the low-frequency power component output from the low-pass filter is used as the target power command for the lithium battery energy unit. The sum of the high-frequency and low-frequency power components equals the automatic generation control power command, ensuring that the total system output accurately tracks the scheduling requirements. It should be noted that the selection of the cutoff frequency of 0.05 Hz is based on the fact that the typical response period of primary frequency regulation in a power system is 0 to 10 seconds, and the response period of secondary frequency regulation is 30 seconds to several minutes. The functional boundary point corresponds to a fluctuation period of approximately 20 seconds, with a corresponding frequency of 0.05 Hz. This boundary frequency corresponds to the physical boundary between primary and secondary frequency modulation, ensuring the functional division of high-frequency components for instantaneous power surges and low-frequency components for continuous energy support. Meanwhile, the response time of the conductive carbon concrete base power unit is no more than 50 milliseconds, enabling distortion-free tracking of high-frequency fluctuations above 0.05 Hz. In contrast, lithium batteries are limited by the electrochemical reaction rate and the control delay of the battery management system, resulting in a response time typically no less than 200 milliseconds. This leads to poor tracking accuracy for rapid fluctuations above 0.05 Hz. The 0.05 Hz boundary ensures that both types of units operate within their optimal response range.

[0057] In this embodiment, the high-frequency component Pf is allocated to the conductive carbon concrete base power unit, and the low-frequency component Ps is allocated to the containerized lithium battery energy unit. The high-frequency component corresponds to the initial rapid change portion of the secondary frequency regulation command, and the low-frequency component corresponds to the subsequent continuous power output portion. Simultaneously, for planned slow charging and discharging commands such as demand regulation commands, since these commands change slowly, the intelligent cooperative controller does not perform filtering decomposition but directly allocates all power commands to the lithium battery energy unit for execution. In this scenario, the base power unit is in standby or float charging state and does not actively undertake power output tasks. Therefore, this embodiment sets three operating modes according to grid security attributes and response urgency, from high to low: primary frequency regulation, secondary frequency regulation, and demand regulation. When a primary frequency regulation event and a secondary frequency regulation command occur simultaneously, the intelligent cooperative controller does not use a queue waiting mechanism but instead uses real-time priority preemption and smooth power transfer. Specifically, when the frequency deviation detection channel determines that a primary frequency regulation event has been triggered, the scheduling command receiving channel is also receiving an automatic generation control power command. When both channels output the target power simultaneously, the following arbitration logic is executed: Upon triggering a primary frequency regulation event, the intelligent collaborative controller initiates the highest priority control. The power command of the base power unit is set to the primary frequency regulation target power. The entire power capacity of the base unit is prioritized for primary frequency regulation response. Then, the high-frequency component obtained from the decomposition of the automatic generation control power command is not temporarily allocated to the base unit, but is merged with the low-frequency component and transferred entirely to the lithium battery energy unit. The lithium battery energy unit tracks the merged total power command at its maximum response rate. After power allocation, a power closed-loop verification is performed. The sum of the base power command and the lithium battery power command equals the sum of the primary frequency regulation target power and the automatic generation control power command, ensuring that the total output power of the system meets the grid demand. When the frequency deviation returns to the dead zone range and the primary frequency regulation event ends, the system automatically reverts to the normal secondary frequency regulation collaborative mode. The base unit resumes receiving the high-frequency component of the automatic generation control power command, and the lithium battery unit receives the low-frequency component. If primary frequency regulation and demand regulation occur concurrently, the power demand of demand regulation is all superimposed on the lithium battery energy unit for execution, without occupying the power resources of the base power unit throughout the process.

[0058] In this embodiment, the intelligent collaborative controller also needs to monitor the State of Charge (SOC) reported by the capacitor management system of the base power unit in real time. For the base power unit, the target operating SOC range set by the intelligent collaborative controller is 55% to 70%. When the SOC of the base power unit is lower than 50%, the intelligent collaborative controller sends a command to the bidirectional energy storage converter to draw power from the grid during periods without frequency regulation tasks, or sends a command to the battery management system of the lithium battery energy unit to charge the base unit at a low power, so that the SOC of the base unit is restored to the target SOC range. When the SOC of the base power unit is higher than 75%, the intelligent collaborative controller can instruct the base unit to discharge at a low power to the grid or the lithium battery unit, so that the SOC of the base power unit is restored to the target SOC range.

[0059] Under normal secondary frequency regulation operation, when the state of charge (SOC) of the base unit deviates from the target SOC range, the intelligent co-controller adds a small power correction term to the high-frequency power component. The absolute value of the small power correction term is no greater than 5% of the base's rated power. During frequency regulation intervals, the base's SOC is slowly restored, and this correction term is synchronously added in reverse to the lithium battery power command, ensuring that the sum of the high-frequency and low-frequency components is still equal to the total power command of the automatic power generation control, thus maintaining the system's total output power. It should be noted that the intelligent co-controller also needs to limit all allocated power commands. Specifically, it controls the power command of the base power unit to not exceed the unit's maximum allowable output power, which is determined by the current SOC and converter capacity; it controls the power command of the lithium battery energy unit to not exceed the unit's maximum allowable output power; and it controls the sum of the power commands of the base power unit and the lithium battery energy unit to not exceed the rated power of the energy storage container.

[0060] Meanwhile, the core control parameters of the intelligent collaborative controller are configured before the system is put into operation. Specifically, the frequency dead zone parameter is set to ±0.03 Hz, which determines the trigger threshold of the primary frequency regulation event; the droop coefficient parameter is calculated based on the rated power of the energy storage container and the grid frequency regulation rules, determining the power output amplitude corresponding to the frequency deviation; the filter cutoff frequency parameter is set to 0.05 Hz, determining the separation boundary between high-frequency and low-frequency components; the target state of charge range parameter for the base is set to 55% to 70%, determining the normal operating range of the base's state of charge; and the base's state of charge recharge initiation threshold parameter is set to 50%, determining the initiation of the recharge procedure when the base's state of charge is below this value. The above control parameters can be optimized and adjusted according to the actual operating data of the grid, but the adjustment must be carried out during system shutdown and maintenance, and the parameters are not modified during operation.

[0061] In summary, this embodiment, by setting up an intelligent collaborative controller and adopting an architecture with two independent channels for frequency deviation detection and scheduling command reception operating in parallel and with priority arbitration, achieves priority preemption of the base power unit by the primary frequency modulation command and separation and allocation of the high and low frequency components of the secondary frequency modulation command. This allows the power-type energy storage unit to be responsible for rapid response and the energy-type energy storage unit to be responsible for continuous support, with the two not interfering with each other and cooperating in a coordinated manner. At the same time, through closed-loop correction of the state of charge and power limiting protection, it ensures that each unit operates within a safe range, realizing coordinated control and full life cycle economic optimization of the hybrid energy storage system.

[0062] This invention provides a conductive carbon concrete base hybrid energy storage and coordinated frequency regulation system. The system includes a conductive carbon concrete base power unit, a containerized lithium battery energy unit, and an intelligent coordinated controller. The conductive carbon concrete base power unit includes a conductive carbon concrete energy storage body and multiple sets of parallel electrodes embedded in the conductive carbon concrete energy storage body. The electrodes are used to extract the electrical energy stored in the conductive carbon concrete energy storage body. The intelligent coordinated controller is used to decompose the received total power command into power components corresponding to different response time scales according to the grid frequency deviation signal, and allocate the instantaneous power component corresponding to the first frequency regulation to the conductive carbon concrete base power unit, and allocate the continuous power component corresponding to the second frequency regulation to the containerized lithium battery energy unit. Compared with existing technologies, this system transforms the conductive carbon concrete base into a power unit that combines structural support and supercapacitor energy storage. It connects the base in parallel with the lithium battery energy unit inside the container on the DC side and uses an intelligent collaborative controller to decompose the grid power command into power components corresponding to different response time scales. These components are then distributed to the base power unit to handle instantaneous high-frequency power and to the lithium battery energy unit to handle continuous low-frequency power. This achieves the division of labor between power-type and energy-type energy storage on the time scale without increasing additional floor space or cost. The base can respond to frequency regulation in milliseconds while avoiding frequent and rapid charging and discharging of the lithium battery, thus extending its cycle life. Ultimately, this system achieves simultaneous improvement in frequency regulation response performance, lithium battery cycle life, and overall life-cycle economics.

[0063] In one embodiment, such as Figure 6 As shown, this embodiment of the invention provides a method for coordinated frequency regulation of hybrid energy storage on a conductive carbon concrete base, applying the aforementioned conductive carbon concrete base hybrid energy storage coordinated frequency regulation system. The method includes the following steps: S1. Monitor the grid frequency deviation signal at the grid access point and the total power command issued by the grid dispatch center in real time, and determine whether the grid frequency deviation signal exceeds the preset frequency dead zone.

[0064] S2. If the power grid frequency deviation signal exceeds the preset frequency dead zone, it is determined to be a primary frequency modulation event, and the total power command is allocated as the instantaneous power component of the primary frequency modulation to the conductive carbon concrete base power unit to perform instantaneous power response.

[0065] S3. If the power grid frequency deviation signal does not exceed the preset frequency dead zone, it is determined to be a secondary frequency modulation event. The total power command is decomposed into power components corresponding to different response time scales to obtain the high-frequency power component of the primary frequency modulation time scale and the low-frequency power component of the secondary frequency modulation time scale.

[0066] S4. The high-frequency power component is allocated to the conductive carbon concrete base power unit for execution, and the low-frequency power component is allocated to the container lithium battery energy unit for execution.

[0067] In some embodiments, the conductive carbon concrete base hybrid energy storage and coordinated frequency modulation method provided in this embodiment further includes the following steps: The state of charge of the conductive carbon concrete base power unit is monitored in real time. When the state of charge deviates from the preset target state of charge range and the system is in a frequency modulation event gap, the bidirectional DC converter is controlled to draw power from the common DC bus to charge the conductive carbon concrete base power unit, so that it is restored to the target state of charge range.

[0068] It should be noted that the sequence numbers of the above processes do not imply a sequential order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application. For specific limitations on a conductive carbon concrete base hybrid energy storage coordinated frequency regulation method, please refer to the above limitations on a conductive carbon concrete base hybrid energy storage coordinated frequency regulation system, which will not be repeated here. Those skilled in the art will recognize that the various modules and steps described in conjunction with the embodiments disclosed in this application can be implemented in hardware, software, or a combination of both. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0069] This invention provides a method for coordinated frequency regulation of hybrid energy storage on a conductive carbon concrete base. The method includes real-time monitoring of the grid frequency deviation signal at the grid connection point and the total power command issued by the grid dispatch center, and determining whether the grid frequency deviation signal exceeds a preset frequency dead zone. If the grid frequency deviation signal exceeds the preset frequency dead zone, it is determined as a primary frequency regulation event, and the total power command is allocated as the instantaneous power component of the primary frequency regulation to the conductive carbon concrete base power unit for instantaneous power response. If the grid frequency deviation signal does not exceed the preset frequency dead zone, it is determined as a secondary frequency regulation event, and the total power command is decomposed into power components corresponding to different response time scales to obtain a high-frequency power component at the primary frequency regulation time scale and a low-frequency power component at the secondary frequency regulation time scale. The high-frequency power component is allocated to the conductive carbon concrete base power unit for execution, and the low-frequency power component is allocated to the containerized lithium battery energy unit for execution. Compared with existing technologies, this method transforms the conductive carbon concrete base into a power unit that combines structural support and supercapacitor energy storage. This power unit is connected in parallel with the lithium battery energy unit inside the container on the DC side. By using an intelligent collaborative controller, the power command from the grid is decomposed into power components corresponding to different response time scales. These components are then allocated to the base power unit to handle instantaneous high-frequency power and to the lithium battery energy unit to handle continuous low-frequency power. This achieves a division of labor between power-type and energy-type energy storage on a time scale without increasing additional space or cost. This allows the base to respond to frequency regulation in milliseconds while avoiding frequent and rapid charging and discharging of the lithium battery, thus extending its cycle life. Ultimately, this method achieves a simultaneous improvement in frequency regulation response performance, lithium battery cycle life, and overall life-cycle economics.

[0070] The embodiments described above are merely preferred embodiments of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various improvements and substitutions without departing from the technical principles of this invention, and these improvements and substitutions should also be considered within the scope of protection of this application. Therefore, the scope of protection of this patent application should be determined by the scope of the claims.

Claims

1. A conductive carbon concrete base hybrid energy storage and coordinated frequency regulation system, characterized in that, include: The system includes a conductive carbon concrete base power unit, a containerized lithium battery energy unit, and an intelligent collaborative controller. The conductive carbon concrete base power unit and the containerized lithium battery energy unit are connected in parallel via a common DC bus. The common DC bus is connected to the grid access point via a bidirectional energy storage converter. The conductive carbon concrete base power unit is connected to a common DC bus via a bidirectional DC converter; the conductive carbon concrete base power unit includes a conductive carbon concrete energy storage body and multiple sets of parallel electrodes embedded in the conductive carbon concrete energy storage body, the electrodes being used to draw out the electrical energy stored in the conductive carbon concrete energy storage body. The containerized lithium battery energy unit includes a lithium battery cluster and a battery management system inside the container. The intelligent collaborative controller is communicatively connected to the battery management system, the bidirectional DC-DC converter, and the bidirectional energy storage converter, respectively. It is used to decompose the received total power command into power components corresponding to different response time scales according to the grid frequency deviation signal, and allocate the instantaneous power component corresponding to the first frequency regulation to the conductive carbon concrete base power unit, and allocate the continuous power component corresponding to the second frequency regulation to the container lithium battery energy unit.

2. The conductive carbon concrete base hybrid energy storage and coordinated frequency regulation system as described in claim 1, characterized in that: The conductive carbon concrete base power unit is installed at the bottom of the energy storage container. The conductive carbon concrete base power unit also includes a high insulation layer covering the outer surface of the conductive carbon concrete energy storage body, a static dissipation layer coated on the outer surface of the high insulation layer, and an insulating pad block installed between the conductive carbon concrete energy storage body and the energy storage container. The static dissipation layer is connected to the grounding terminal through a pre-embedded grounding conductor. The high-insulation isolation layer is used to electrically isolate the internally charged conductive carbon concrete energy storage body from the outside, and the electrostatic dissipation layer is used to discharge the static charge accumulated on the surface of the conductive carbon concrete base power unit.

3. The conductive carbon concrete base hybrid energy storage and coordinated frequency regulation system as described in claim 1, characterized in that: Each set of parallel electrodes includes a positive electrode plate and a negative electrode plate. The multiple sets of parallel electrodes are arranged in parallel along the length direction of the conductive carbon concrete energy storage body in an alternating sequence of positive and negative electrodes. The planes of each positive electrode plate and each negative electrode plate are perpendicular to the length direction of the conductive carbon concrete energy storage body.

4. The conductive carbon concrete base hybrid energy storage and coordinated frequency regulation system as described in claim 1, characterized in that: The conductive carbon concrete energy storage body uses cement as the matrix, nano-carbon black as the conductive functional phase, and fine and coarse aggregates as the skeleton, forming a three-dimensional conductive network during the cement hydration process.

5. The conductive carbon concrete base hybrid energy storage and coordinated frequency regulation system as described in claim 1, characterized in that: The intelligent collaborative controller is equipped with a digital filter; The digital filter is used to decompose the total power command into a high-frequency power component corresponding to the first frequency modulation time scale and a low-frequency power component corresponding to the second frequency modulation time scale. The high-frequency power component is used as the instantaneous power component of the first frequency modulation, and the low-frequency power component is used as the continuous power component of the second frequency modulation. The filter then sends the power command corresponding to the instantaneous power component to the bidirectional DC-DC converter and sends the power command corresponding to the continuous power component to the battery management system.

6. The conductive carbon concrete base hybrid energy storage and coordinated frequency regulation system as described in claim 1, characterized in that: When the grid frequency deviation signal exceeds the preset frequency dead zone and there is an automatic power generation control command for secondary frequency regulation, the intelligent cooperative controller is also used to allocate all the instantaneous power components of the primary frequency regulation to the conductive carbon concrete base power unit for execution, transfer all the power of the automatic power generation control command to the container lithium battery energy unit for execution, and restore the decomposition and allocation of the total power command after the grid frequency deviation signal returns to the preset frequency dead zone and remains stable.

7. The conductive carbon concrete base hybrid energy storage and coordinated frequency regulation system as described in claim 1, characterized in that: The intelligent collaborative controller is also used to monitor the state of charge of the conductive carbon concrete base power unit in real time, and when the state of charge is not in the preset target state of charge range and the system is in a frequency modulation event gap, it controls the bidirectional DC converter to draw power from the common DC bus to charge the conductive carbon concrete base power unit, so that it returns to the preset target state of charge range.

8. The conductive carbon concrete base hybrid energy storage and coordinated frequency regulation system as described in claim 1, characterized in that: The DC output terminal of the container lithium battery energy unit is directly connected to a common DC bus, and the rated voltage of the common DC bus is the same as the rated output voltage of the container lithium battery cluster. The bidirectional DC-DC converter is an isolated bidirectional DC-DC converter. The low-voltage side of the bidirectional DC-DC converter is connected to the electrodes of the conductive carbon concrete base power unit, and the high-voltage side of the bidirectional DC-DC converter is connected to the common DC bus. The bidirectional DC-DC converter operates in boost mode under discharge conditions and in buck mode under charging conditions.

9. A method for coordinated frequency modulation of hybrid energy storage on a conductive carbon concrete base, characterized in that, The method of using the conductive carbon concrete base hybrid energy storage and coordinated frequency regulation system as described in any one of claims 1 to 8 includes the following steps: The system monitors the grid frequency deviation signal at the grid access point and the total power command issued by the grid dispatch center in real time, and determines whether the grid frequency deviation signal exceeds the preset frequency dead zone. If the power grid frequency deviation signal exceeds the preset frequency dead zone, it is determined to be a primary frequency modulation event, and the total power command is allocated as the instantaneous power component of the primary frequency modulation to the conductive carbon concrete base power unit to perform instantaneous power response. If the power grid frequency deviation signal does not exceed the preset frequency dead zone, it is determined to be a secondary frequency modulation event. The total power command is decomposed into power components corresponding to different response time scales to obtain the high-frequency power component of the primary frequency modulation time scale and the low-frequency power component of the secondary frequency modulation time scale. The high-frequency power component is allocated to the conductive carbon concrete base power unit for execution, and the low-frequency power component is allocated to the container lithium battery energy unit for execution.

10. The method for hybrid energy storage and coordinated frequency modulation of a conductive carbon concrete base as described in claim 9, characterized in that, The method further includes: The state of charge of the conductive carbon concrete base power unit is monitored in real time. When the state of charge deviates from the preset target state of charge range and the system is in a frequency modulation event gap, the bidirectional DC converter is controlled to draw power from the common DC bus to charge the conductive carbon concrete base power unit, so that it is restored to the target state of charge range.

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