Bidirectional coupling flywheel and compressed air integrated energy storage system control method, system, equipment and medium

Abstract

The invention discloses a bidirectional coupling flywheel and compressed air integrated energy storage system control method, system and device and a medium. The method comprises the following steps: collecting multi-dimensional parameters and power grid demand power of a bidirectional coupling flywheel and compressed air integrated energy storage system; calculating the multi-dimensional parameters to form an energy storage state evaluation result; filtering the required power of the power grid, calculating the power change rate through the filtered required power of the power grid, and judging the fluctuation level of the power grid according to the power change rate; and converting the system working mode into a digital quantity instruction, and executing mode switching according to the digital quantity instruction. According to the method, the power grid fluctuation level is judged according to the power change rate, the four-level priority multi-constraint judgment logic of safety constraint priority, fluctuation response subordinate, power matching subordinate and energy storage balance supplement is established, and accurate matching of eight system working modes is achieved.

Description

Technical Field

[0001] This invention relates to the field of energy storage and power transmission technology, and in particular to a control method, system, device and medium for a bidirectional coupled flywheel and compressed air integrated energy storage system. Background Technology

[0002] In new energy power systems, energy storage technology is a core supporting means to smooth out fluctuations in new energy output and ensure the stable operation of the power grid. Among the mainstream energy storage technologies, flywheel energy storage has the advantages of fast response speed and high power density, but it has the disadvantages of limited energy storage capacity and short continuous power supply time; compressed air energy storage has the characteristics of large capacity and long energy storage cycle, but it has the disadvantages of slow response and weak power regulation capability. In order to combine the advantages of both, the industry has gradually explored the composite energy storage solution of flywheel and compressed air, but the existing composite energy storage systems and control methods still have key technical problems, which make it difficult to meet the comprehensive requirements of the power grid for energy storage systems to have "high response speed, large capacity storage, stable and efficient operation, and smooth mode switching".

[0003] The existing control methods for composite energy storage systems lack sufficient accuracy in terms of operating condition perception. The parameter acquisition of existing systems mostly adopts a single sensor and discrete sampling method, which makes it difficult to comprehensively acquire multi-dimensional operating condition data such as flywheel speed and gas tank pressure. Control decisions based on such data cannot accurately match the power demand of the grid with the energy storage status of the system, which is prone to mode misjudgment or power distribution imbalance. Furthermore, it is difficult to balance response speed and energy storage capacity. Existing systems have not established a graded response mechanism for the characteristics of grid power fluctuations. When faced with high-frequency grid fluctuations, the slow response of the compressed air unit cannot smooth out the fluctuations in time, while the limited capacity of the flywheel is difficult to meet the long-term power supply requirements when faced with continuous high-power charging and discharging demands. Summary of the Invention

[0004] In view of the aforementioned existing problems, the present invention is proposed.

[0005] Therefore, this invention provides a control method, system, device, and medium for a bidirectional coupled flywheel and compressed air integrated energy storage system to solve the problems of insufficient operating condition perception accuracy, lack of precision in control decision-making, and difficulty in balancing response speed and energy storage capacity in existing composite energy storage systems.

[0006] To solve the above-mentioned technical problems, the present invention provides the following technical solution: In a first aspect, the present invention provides a control method for a bidirectional coupled flywheel and compressed air integrated energy storage system, comprising the following steps: acquiring multi-dimensional parameters of the bidirectional coupled flywheel and compressed air integrated energy storage system and the grid demand power; calculating the multi-dimensional parameters to form an energy storage status assessment result; filtering the grid demand power and calculating the power change rate based on the filtered grid demand power, and determining the grid fluctuation level based on the power change rate; performing multi-constraint judgment on the energy storage status assessment result and the grid fluctuation level according to the priority order of multiple sets of constraints to determine the system operating mode; converting the system operating mode into digital commands, and performing mode switching according to the digital commands.

[0007] As a preferred embodiment of the control method for the bidirectional coupled flywheel and compressed air integrated energy storage system described in this invention, the step of calculating the multi-dimensional parameters to form an energy storage state assessment result includes: calculating the available kinetic energy of the flywheel based on the flywheel moment of inertia and flywheel speed of the multi-dimensional parameters; calculating the upper limit of the available power of the flywheel based on the maximum torque of the flywheel shaft and flywheel speed of the multi-dimensional parameters; calculating the compressed air energy of the air tank based on the air tank pressure, air tank volume, and specific heat ratio of the multi-dimensional parameters; calculating the upper limit of the available power of the compressed air system based on the expander adiabatic efficiency, air tank pressure, air tank volume, specific heat ratio, local atmospheric pressure, and expander continuous working time of the multi-dimensional parameters; and outputting the available kinetic energy of the flywheel, the upper limit of the available power of the flywheel, the compressed air energy of the air tank, and the upper limit of the available power of the compressed air system as the energy storage state assessment result.

[0008] As a preferred embodiment of the control method for the bidirectional coupled flywheel and compressed air integrated energy storage system described in this invention, the step of filtering the grid demand power includes: obtaining the grid demand power at the current sampling time and the grid demand power at the previous two sampling times; summing the grid demand power at the current sampling time, the grid demand power at the previous sampling time, and the grid demand power at the previous two sampling times and taking the average value to obtain the filtered grid demand power; comparing the filtered grid demand power with the grid demand power at the current sampling time, and when the absolute value of the difference between the two is greater than a preset percentage of the rated power, using the median of the grid demand power of the previous five sampling periods to replace the filtered grid demand power.

[0009] The beneficial effects of this preferred technical solution are as follows: It adopts a dual data processing mechanism of 3-point moving average filtering combined with median substitution. When the deviation between the filtered value and the original value exceeds the preset percentage of the rated power, it automatically switches to median filtering, thereby eliminating instantaneous pulse interference and abnormal data on the grid side.

[0010] As a preferred embodiment of the control method for the bidirectional coupled flywheel and compressed air integrated energy storage system described in this invention, the step of calculating the power change rate based on the filtered grid demand power and determining the grid fluctuation level based on the power change rate includes: calculating the difference between the filtered grid demand power at the current sampling time and the filtered grid demand power at the previous sampling time, dividing the difference by a fixed sampling period to obtain the power change rate; determining whether the absolute value of the power change rate is greater than a preset change rate threshold; when the absolute value of the power change rate is greater than the preset change rate threshold for two consecutive sampling periods, determining the grid fluctuation level as high-frequency fluctuation; when the absolute value of the power change rate is not greater than the preset change rate threshold for two consecutive sampling periods, determining the grid fluctuation level as non-high-frequency fluctuation.

[0011] The beneficial effects of this preferred technical solution are: by using the judgment condition of "two consecutive sampling periods", misjudgment caused by a single occasional fluctuation is avoided, and the distinction between high-frequency fluctuations and non-high-frequency fluctuations of the power grid is realized.

[0012] As a preferred embodiment of the control method for the bidirectional coupled flywheel and compressed air integrated energy storage system described in this invention, the step of performing multi-constraint judgment based on the energy storage state assessment results and grid fluctuation levels according to the priority order of multiple sets of constraints includes: determining whether safety constraints are met, wherein the safety constraints include the air tank pressure being greater than the maximum working pressure of the air tank or the flywheel's available kinetic energy being less than the flywheel's minimum safe kinetic energy; when the safety constraints are met, determining the system operating mode based on the safety constraints; when the safety constraints are not met, determining whether fluctuation response constraints are met, wherein the fluctuation response constraints are high-frequency fluctuations in the grid; when the fluctuation response constraints are met, determining the system operating mode based on the fluctuation response constraints; when the fluctuation response constraints are not met, determining whether power matching constraints are met, wherein the absolute value of the grid demand power is simultaneously greater than both the flywheel's available power limit and the compressed air system's available power limit; when the power matching constraints are met, determining the system operating mode based on the power matching constraints; when the power matching constraints are not met, determining whether energy storage balance constraints are met, and determining the system operating mode based on the energy storage balance constraints or default conditions.

[0013] The beneficial effects of this preferred technical solution are: establishing a four-level priority order of "safety constraints → fluctuation response → power matching → energy storage balance" to ensure that the system always prioritizes equipment safety when multiple objectives conflict, while also taking into account response speed and operating efficiency.

[0014] As a preferred embodiment of the control method for the bidirectional coupled flywheel and compressed air integrated energy storage system described in this invention, the step of determining the system operating mode includes: when the safety constraints are met and the pressure of the gas storage tank is greater than the maximum operating pressure of the gas storage tank and the power demand of the grid is less than zero, determining the system operating mode as the discharge compressed air independent response mode; when the safety constraints are met and the available kinetic energy of the flywheel is less than the minimum safe kinetic energy of the flywheel and the power demand of the grid is less than zero, determining the system operating mode as the discharge compressed air dominant mode; when the fluctuation response constraints are met and the power demand of the grid is greater than zero, determining the system operating mode as the charging flywheel independent response mode; when the fluctuation response constraints are met and the power demand of the grid is less than zero, determining the system operating mode as the discharge compressed air dominant ... The system operates in the following modes: discharge flywheel alone response mode; charging hybrid mode when the power matching constraint is met and the grid demand is greater than zero; discharging hybrid mode when the power matching constraint is met and the grid demand is less than zero; charging flywheel priority mode when the energy storage balance constraint is met and the ratio of the flywheel's available kinetic energy to its rated kinetic energy is less than the first energy storage threshold; charging compressed air priority mode when the energy storage balance constraint is met and the ratio of the gas tank pressure to the gas tank's maximum operating pressure is less than the second energy storage threshold; and standby mode when the absolute value of the grid demand is less than the preset proportional threshold of the rated power.

[0015] As a preferred embodiment of the control method for the bidirectional coupled flywheel and compressed air integrated energy storage system described in this invention, the step of converting the system operating mode into a digital instruction includes: converting the determined system operating mode into an 8-bit digital instruction according to a preset encoding rule, wherein the charging flywheel priority mode corresponds to the first code, the charging compressed air priority mode corresponds to the second code, the charging hybrid mode corresponds to the third code, the discharging flywheel independent response mode corresponds to the fourth code, the discharging compressed air independent response mode corresponds to the fifth code, the discharging hybrid mode corresponds to the sixth code, and the standby mode corresponds to the seventh code; when outputting the digital instruction, a mode switching preparation signal is attached, which is used to inform the switching control module to complete the pre-synchronization and torque gradual change preparation actions in advance.

[0016] The beneficial effects of this preferred technical solution are as follows: by using 8-bit digital instruction encoding and attaching a mode switching preparation signal, the switching control module can perform pre-synchronization and torque gradual change preparation actions in advance, thus shortening the mode switching time.

[0017] Secondly, the present invention provides a control system for a bidirectional coupled flywheel and compressed air integrated energy storage system, comprising: a parameter acquisition module for acquiring multi-dimensional parameters of the bidirectional coupled flywheel and compressed air integrated energy storage system and the power demand of the grid. The energy storage status calculation module is used to calculate the multi-dimensional parameters and form an energy storage status assessment result; The fluctuation determination module is used to filter the power demand of the power grid, calculate the power change rate through the filtered power demand, and determine the power fluctuation level based on the power change rate. The mode decision module is used to determine the system operating mode by performing multi-constraint judgment based on the energy storage status assessment results and the grid fluctuation level according to the priority order of multiple sets of constraints. The switching control module is used to convert the system's operating mode into digital instructions and perform mode switching according to the digital instructions.

[0018] Thirdly, the present invention provides an electronic device, comprising: Memory and processor; The memory is used to store computer-executable instructions, and the processor is used to execute the computer-executable instructions. When the computer-executable instructions are executed by the processor, they implement the steps of the control method for the bidirectional coupled flywheel and compressed air integrated energy storage system.

[0019] Fourthly, the present invention provides a computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, implement the steps of the control method for the bidirectional coupled flywheel and compressed air integrated energy storage system.

[0020] Compared with existing technologies, the beneficial effects of this invention are as follows: By collecting multi-dimensional parameters and calculating the energy storage status assessment results, and combining a dual data processing mechanism of moving average filtering and median substitution, the power demand of the power grid is preprocessed. The power grid fluctuation level is determined based on the power change rate, and a four-level priority multi-constraint judgment logic of "safety constraints first, fluctuation response second, power matching third, and energy storage balance supplement" is established to achieve accurate matching of eight system operating modes. Through the output mechanism of 8-bit digital instruction encoding and mode switching preparation signal, the system can complete pre-synchronization and torque gradual change preparation actions in advance, thereby reducing mechanical shock and current fluctuations during mode switching. Attached Figure Description

[0021] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of the overall process of the control method for the integrated bidirectional coupled flywheel and compressed air energy storage system according to an embodiment of the present invention. Detailed Implementation

[0023] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present invention.

[0024] Example 1, referring to Figure 1 As an embodiment of the present invention, a control method for a bidirectional coupled flywheel and compressed air integrated energy storage system is provided, comprising the following steps: S100 collects multi-dimensional parameters and grid demand power of the bidirectional coupled flywheel and compressed air integrated energy storage system.

[0025] S200. Calculate the multi-dimensional parameters to form an energy storage status assessment result.

[0026] S300. Filter the power demand of the power grid, calculate the power change rate based on the filtered power demand, and determine the power fluctuation level based on the power change rate.

[0027] S400: The energy storage status assessment results and grid fluctuation levels are used to determine the system operating mode by performing multi-constraint judgment according to the priority order of multiple sets of constraints.

[0028] S500: Convert the system's operating mode into a digital instruction and switch the mode according to the digital instruction.

[0029] It should be noted that in new energy power systems, flywheel energy storage has the advantages of fast response speed and high power density, but it has the disadvantages of limited energy storage capacity and short continuous power supply time. Compressed air energy storage, on the other hand, has the characteristics of large capacity and long energy storage cycle, but it has the disadvantages of slow response and weak power regulation capability. Existing composite energy storage systems mostly adopt simple mechanical coupling or discrete structures with independent control, lacking efficient bidirectional power distribution units. When the system switches between different modes such as charging and discharging, it cannot achieve a smooth power transition between the flywheel and the compressed air unit, which is prone to large mechanical shocks and current fluctuations. At the same time, the parameter acquisition of existing systems mostly adopts single sensor and discrete sampling methods, which makes it difficult to comprehensively obtain multi-dimensional operating condition data such as flywheel speed and air tank pressure. Control decisions based on such data cannot accurately match the power demand of the grid and the energy storage status of the system, which is prone to mode misjudgment or power distribution imbalance. In addition, existing control methods have not established a scientific constraint priority ranking, and cannot make optimal decisions when multiple objectives such as safety constraints, efficiency optimization, and response speed conflict, making it difficult for the system to adapt to the complex and ever-changing operating conditions of the power grid.

[0030] Therefore, to address the aforementioned issues of operating condition perception, mode decision-making, and response control, the following steps (S100-S500) are employed: multi-dimensional parameters are collected at a fixed sampling period, and energy storage status assessment results are calculated to achieve precise matching between grid power demand and system energy storage status; a dual data processing mechanism combining moving average filtering and median substitution is used to eliminate instantaneous pulse interference on the grid side, and accurate determination of grid fluctuation levels is achieved based on the power change rate; a four-level priority multi-constraint judgment logic is established: "safety constraints first, fluctuation response second, power matching third, and energy storage balance supplement," achieving precise matching of eight system operating modes; and a digital command encoding and mode switching preparation signal output mechanism enables the system to complete pre-synchronization and torque gradual change preparation actions in advance, effectively reducing mechanical shocks and current fluctuations during mode switching and improving the system's operating efficiency and reliability across the entire operating condition range.

[0031] Example 2, refer to Figure 1 As an embodiment of the present invention, based on the above embodiment, a control method for a bidirectional coupled flywheel and compressed air integrated energy storage system is provided.

[0032] In this embodiment of the application, S100 collects multi-dimensional parameters and grid demand power of the bidirectional coupled flywheel and compressed air integrated energy storage system.

[0033] Specifically, by using a fixed sampling period of 10ms, a sensor array is used to synchronously acquire multi-dimensional parameters. The acquisition methods for each parameter are as follows: Power demand acquisition: A 0.2-class high-precision three-phase power transmitter is selected and connected in series in the connection line between the power grid and the power converter. The output of the transmitter is connected to the data acquisition card through a shielded cable to acquire the instantaneous charging / discharging power value at the k-th sampling time. During charging, the power demand of the power grid is greater than zero, and during discharging, the power demand of the power grid is less than zero.

[0034] Flywheel speed acquisition: A dual-channel Hall effect speed sensor is selected and fixed on the frame bracket on the side of the flywheel shaft. The radial clearance between the probe and the integrally formed signal gear ring on the shaft is strictly controlled within 1~2mm. A 5mm thick silicone rubber anti-vibration pad is added to the bottom of the bracket to avoid the vibration generated by the high-speed rotation of the flywheel from affecting the measurement accuracy. When the speed fluctuation is less than or equal to 5r / min, it is judged as stable operation. If it exceeds, the speed calibration mechanism is triggered.

[0035] Pressure acquisition of the gas storage tank: A diffused silicon high-pressure transmitter is selected and installed vertically at the tee joint of the outlet pipeline of the high-pressure gas storage tank. The interface is double-sealed with PTFE sealing tape and metal gasket to prevent high-pressure gas leakage. Zero-point calibration is automatically performed every 24 hours to ensure long-term operating accuracy. Instantaneous pulse interference must be removed from the pressure sampling value.

[0036] Clutch temperature acquisition: An armored PT100 resistance temperature detector (RTD) sensor is selected and embedded in the friction plate mounting groove. The probe is in direct contact with the end face of the friction plate. The mounting hole is filled with high-temperature sealant to prevent dust from entering and heat loss.

[0037] The acquisition of rotational speeds of various components in the planetary gear system: Dual-channel Hall effect speed sensors are selected. The sun gear side sensor is installed on the outside of the flange connecting the motor output shaft and the sun gear. The planet carrier side sensor is installed on the end cover of the planet carrier support bearing. The gear ring side sensor is installed on the frame corresponding to the outer circle of the gear ring. The three-channel sensors are sampled simultaneously through the FPGA synchronous trigger module, with a sampling time difference of less than or equal to 1μs, to ensure the accuracy of the calculation of the rotational speed relationship of various components in the planetary gear system.

[0038] In this embodiment of the application, S200 calculates the multi-dimensional parameters to form an energy storage state assessment result. Specifically, this includes: A1. Calculate the available kinetic energy of the flywheel based on the flywheel moment of inertia and flywheel speed, which are multi-dimensional parameters.

[0039] Specifically, the flywheel can utilize kinetic energy The calculation formula is: ,in, The moment of inertia of the flywheel. Let represent the flywheel speed at the k-th sampling time. The flywheel moment of inertia is determined using a combination of static calibration and dynamic verification. Static calibration calculates the theoretical value using SolidWorks, while dynamic verification involves measuring the angular acceleration during free deceleration after the flywheel is unloaded and combining this with air resistance torque to deduce the actual moment of inertia. The final value is the weighted average of the two methods, with the dynamic verification result having a weight of 0.7 and the static theoretical value having a weight of 0.3. The minimum safe kinetic energy of the flywheel is set at 5% of its rated kinetic energy. When the available kinetic energy of the flywheel is less than the minimum safe kinetic energy, it is considered that the flywheel has insufficient energy storage, and the flywheel is prohibited from outputting power independently. When the available kinetic energy of the flywheel is greater than 95% of its rated kinetic energy, it is considered that the flywheel is saturated, and charging the flywheel is prohibited to avoid overspeed damage.

[0040] A2. Calculate the upper limit of the flywheel's usable power based on the flywheel shaft's maximum torque and flywheel speed, which are multi-dimensional parameters.

[0041] Flywheel available power limit The calculation formula is: ,in, The maximum torque of the flywheel shaft, Let be the flywheel speed at the k-th sampling time. The maximum torque of the flywheel shaft is calculated using the torsional strength formula. Calculate, where, The flywheel shaft diameter is determined by the strength calculation of the shaft material and verified by static loading using a torque testing machine to ensure no plastic deformation. When the absolute value of the power demand of the power grid exceeds the upper limit of the flywheel's available power, the single flywheel path cannot meet the demand, and a hybrid mode needs to be activated. The upper limit of the flywheel's available power is dynamically adjusted and recalculated every 500 r / min change in flywheel speed to ensure the real-time performance of power constraints.

[0042] A3. Calculate the compressed air energy of the air tank based on the multi-dimensional parameters of the air tank pressure, air tank volume, and specific heat ratio.

[0043] Specifically, compressed air energy storage tank The calculation formula is: ,in, Let be the pressure of the gas storage tank at the k-th sampling time. γ represents the volume of the gas storage tank, and γ represents the specific heat ratio.

[0044] The volume of the air tank is calibrated using the water injection and weighing method, with a calibration accuracy of less than or equal to 0.5%. The specific heat ratio is taken for air medium within the working pressure range. The minimum working pressure of the air tank is set at 1 MPa to avoid damage to the expander due to negative pressure. When the pressure of the air tank is less than the minimum working pressure, the compressed air energy of the air tank is calculated as 0, and the output power of the compressed air system is prohibited. The maximum working pressure of the air tank is set at 30 MPa, which is 80% of the upper limit of the design pressure resistance of the air tank. When the pressure of the air tank is greater than the maximum working pressure, the compressed air energy of the air tank is calculated according to the rated compressed air energy, and it is prohibited to fill the air tank with air.

[0045] A4. Calculate the upper limit of the available power of the compressed air system based on multi-dimensional parameters such as expander adiabatic efficiency, air tank pressure, air tank volume, specific heat ratio, local atmospheric pressure, and expander continuous working time.

[0046] Specifically, the upper limit of available power of the compressed air system The calculation formula is: ,in, For the expansion compressor's insulation efficiency. Let P_{tank(k)} be the specific heat ratio, and let P_{tank(k)} be the pressure of the gas storage tank at the k-th sampling time. For the volume of the gas storage tank, The local atmospheric pressure. This refers to the continuous operating time of the expander. The expander's adiabatic efficiency is calculated by recording the input energy and output mechanical work at different inlet pressures, calculating the average efficiency, and interpolating and storing the segmented efficiency values ​​according to the inlet pressure. Local atmospheric pressure is collected in real-time by an atmospheric pressure sensor and updated hourly to avoid errors caused by altitude and weather changes. The expander's continuous operating time can be adjusted through the central controller parameter configuration interface to adapt to different application scenarios. When the air tank pressure is less than 2MPa, the upper limit of the available power of the compressed air system is calculated with linear decay to avoid inefficient operation of the expander at low pressures. The calculation results need to be overlaid with expander mechanical loss corrections, and the final output is the corrected actual upper limit of power.

[0047] A5. Output the available kinetic energy of the flywheel, the upper limit of the available power of the flywheel, the compressed air energy of the air tank, and the upper limit of the available power of the compressed air system as the energy storage status assessment results.

[0048] Specifically, the calculation process for the energy storage status assessment results is executed in real time by the floating-point arithmetic unit of the central controller. The calculated four indicators—the available kinetic energy of the flywheel, the upper limit of the available power of the flywheel, the compressed air energy of the gas storage tank, and the upper limit of the available power of the compressed air system—are used as the energy storage status assessment results and output to the mode decision module for subsequent multi-constraint determination. Simultaneously, abnormal data is handled: when data from a single sensor exceeds the normal range for three consecutive sampling cycles, a redundant interpolation algorithm is activated, using the average value based on the previous 10 sampling cycles and the flywheel speed derived from the planetary carrier speed for interpolation supplementation; if the abnormal sensor data persists for more than 1 second, it is determined to be a sensor fault, triggering an alarm signal and switching to single-path operation mode, while simultaneously recording the fault time and fault type.

[0049] In this embodiment of the application, S300 filters the power demand of the power grid, calculates the power change rate through the filtered power demand, and determines the power grid fluctuation level based on the power change rate.

[0050] The steps for filtering the power demand of the power grid include B1 to B3: B1. Obtain the power demand of the power grid at the current sampling time and the power demand of the power grid at the previous two sampling times.

[0051] Specifically, the power demand of the power grid at the current sampling time k is read from the buffer of the data acquisition card. Simultaneously read the power demand of the power grid at the previous sampling time. Power demand of the grid at the previous two sampling times The data at the three sampling times were all raw acquisition values ​​after preliminary sensor calibration.

[0052] B2. The power demand of the grid at the current sampling time, the power demand of the grid at the previous sampling time, and the power demand of the grid at the previous two sampling times are summed and averaged to obtain the filtered power demand of the grid.

[0053] The raw data is smoothed using a 3-point moving average filter to eliminate high-frequency pulse interference. The formula for calculating the power demand of the power grid after filtering is as follows: ,in, This represents the filtered power demand of the power grid. The power demand of the power grid at the current sampling time. This represents the power demand of the power grid at the previous sampling time. This represents the power demand of the power grid at the first two sampling times.

[0054] In an optional implementation, the power demand of the grid after filtering in step B2 can also be calculated using a weighted moving average filter. That is, the power demand of the grid at the current sampling time, the previous sampling time, and the two previous sampling times are assigned different weight coefficients and then summed. The weight coefficient at the current sampling time is the largest, and the weight coefficient at the two previous sampling times is the smallest. This makes the filtering result closer to the current actual power state and improves the system's ability to follow power changes.

[0055] B3. Compare the filtered grid demand power with the grid demand power at the current sampling time. When the absolute value of the difference between the two is greater than the preset percentage of the rated power, use the median of the grid demand power of the previous five sampling periods to replace the filtered grid demand power.

[0056] Specifically, after filtering, the validity of the data needs to be verified by calculating the absolute value of the difference between the filtered grid demand power and the grid demand power at the current sampling time. If the absolute value is greater than the rated power A 5% decrease indicates abnormal fluctuations in the original data. In this case, the median of the power demand of the grid over the previous five sampling periods is used to replace the current filter value. , , , , The median is taken as the filtered power demand of the grid to ensure the accuracy of subsequent power change rate calculations.

[0057] In an optional implementation, the data validity verification method in step B3 can also be achieved by analyzing the power change trend of multiple consecutive sampling periods, such as calculating the standard deviation of the power values ​​of the previous N sampling periods. When the standard deviation exceeds a preset threshold, it is determined to be an abnormal fluctuation. At this time, the current filter value is replaced by a linear extrapolation value based on historical data. That is, by fitting the power change curve of the previous few sampling periods, the predicted power value at the current moment is extrapolated as the filtering result.

[0058] It also includes steps B4-B5: calculating the power change rate using the filtered grid demand power, and determining the grid fluctuation level based on the power change rate. B4. Calculate the difference between the filtered power demand of the grid at the current sampling time and the filtered power demand of the grid at the previous sampling time, and divide the difference by the fixed sampling period to obtain the power change rate.

[0059] Specifically, the power change rate between adjacent sampling periods is calculated based on the filtered power value, using the following formula: ,in, With a fixed sampling period of 10ms, This represents the filtered power demand of the power grid at the current sampling time. This represents the filtered power demand of the grid at the previous sampling time. A positive rate of change in power indicates an increase in power demand, meaning that the input power needs to be increased during charging or the output power needs to be increased during discharging; a negative rate of change in power indicates a decrease in power demand.

[0060] B5. Determine whether the absolute value of the power change rate is greater than a preset change rate threshold; When the absolute value of the power change rate is greater than the preset change rate threshold for two consecutive sampling periods, the power grid fluctuation level is determined to be high-frequency fluctuation. When the absolute value of the power change rate does not exceed the preset change rate threshold for two consecutive sampling periods, the power grid fluctuation level is determined to be non-high frequency fluctuation.

[0061] Specifically, the absolute value of the calculated rate of change of power The value is compared with a preset rate of change threshold λ, which is calibrated based on the system's rated power and response characteristics. If the absolute value of the power change rate in both the current and previous sampling periods is greater than the rate of change threshold λ, meaning that two consecutive sampling periods satisfy the condition... If the absolute value of the power change rate does not exceed the change rate threshold λ for two consecutive sampling periods, the power grid fluctuation level is determined to be high-frequency fluctuation, indicating that there is a power fluctuation on the grid side that requires a rapid response. If the absolute value of the power change rate does not exceed the change rate threshold λ for two consecutive sampling periods, the power grid fluctuation level is determined to be non-high-frequency fluctuation, indicating that the power demand on the grid side is relatively stable. By using the determination condition of two consecutive sampling periods, misjudgments caused by single, occasional fluctuations can be effectively avoided, thus improving the reliability of fluctuation level determination.

[0062] In an optional implementation, the method for determining the power grid fluctuation level in step B5 can also be achieved by introducing a multi-level fluctuation classification mechanism. For example, the power grid fluctuation level can be divided into three levels: high-frequency fluctuation, medium-frequency fluctuation, and low-frequency fluctuation, based on the absolute value of the power change rate. The determination can be made by combining the duration and amplitude of the power change rate. That is, when the absolute value of the power change rate continuously exceeds the first threshold, it is determined to be a high-frequency fluctuation; when it continuously exceeds the second threshold but does not exceed the first threshold, it is determined to be a medium-frequency fluctuation; and when it does not exceed the second threshold, it is determined to be a low-frequency fluctuation. This achieves more refined fluctuation characteristic identification.

[0063] In this embodiment of the application, S400 performs multi-constraint judgment based on the energy storage status assessment results and the grid fluctuation level according to the priority order of multiple sets of constraints, and determines the system working mode.

[0064] Specifically, the system establishes a four-level priority ranking: "safety constraints first, fluctuation response second, power matching third, and energy storage balance supplementation," forming a quantitative decision-making logic for all operating conditions. The system has a total of 8 core operating modes, and achieves precise matching of operating modes through multi-constraint judgment.

[0065] The steps for determining multiple constraints by combining the energy storage status assessment results and grid fluctuation levels according to the priority order of multiple sets of constraints include C1 to C4: C1. Determine whether the safety constraints are met. The safety constraints include the gas tank pressure being greater than the maximum working pressure of the gas tank or the flywheel's available kinetic energy being less than the flywheel's minimum safe kinetic energy. When the safety constraints are met, determine the system's operating mode based on the safety constraints.

[0066] Specifically, safety constraints, as priority 1, always take precedence over other constraints to ensure that the system has no safety risks such as overpressure or overspeed. Determine the pressure of the gas storage tank. Is it greater than the maximum working pressure of the gas storage tank? ,in, The pressure is set at 30 MPa, which is 80% of the design pressure limit of the gas storage tank; at the same time, the usable kinetic energy of the flywheel is determined. Is it less than the minimum safe kinetic energy of the flywheel? ,in, The value is set to 5% of the flywheel's rated kinetic energy. When any of the above conditions is met, the safety constraint is deemed to be valid, and the corresponding system operating mode is determined based on the specific type of safety constraint and the direction of power demand from the power grid.

[0067] C2. When the safety constraint is not met, determine whether the fluctuation response constraint is met. The fluctuation response constraint is that the power grid fluctuation level is high frequency fluctuation. When the fluctuation response constraint is met, determine the system working mode according to the fluctuation response constraint.

[0068] Specifically, fluctuation response constraints, as priority 2, are higher than power matching and energy storage balance, prioritizing grid stability. When safety constraints are not met, it is determined whether the grid fluctuation level identified in S300 is a high-frequency fluctuation, i.e., whether the absolute value of the power change rate is greater than the preset change rate threshold λ for two consecutive sampling periods. When fluctuation response constraints are met, it indicates that there is a power fluctuation on the grid side that requires rapid response. Based on the direction of the grid's demand power, a flywheel-only response mode is determined, utilizing the flywheel's high response speed to quickly smooth out fluctuations.

[0069] C3. When the fluctuation response constraint is not met, determine whether the power matching constraint is met. The power matching constraint is that the absolute value of the power demand of the power grid is greater than the upper limit of the available power of the flywheel and the upper limit of the available power of the compressed air system at the same time. When the power matching constraint is met, determine the system operating mode according to the power matching constraint.

[0070] Specifically, the power matching constraint, as priority 3, is used to determine whether a single energy storage path can meet the grid power demand. When the fluctuation response constraint is not met, the absolute value of the grid power demand is determined. Does it simultaneously exceed the flywheel's available power limit? Upper limit of available power for compressed air systems When the power matching constraint is met, it indicates that a single energy storage path cannot meet the power demand of the grid, and the flywheel and compressed air system need to work together to determine the hybrid mode according to the direction of the grid's power demand and allocate or combine power in the optimal ratio.

[0071] C4. When the power matching constraint is not met, determine whether the energy storage balance constraint is met, and determine the system operating mode based on the energy storage balance constraint or the default condition.

[0072] Specifically, the energy storage balance constraint, as priority 4, is activated when there is no power matching requirement to optimize the system's energy storage distribution and improve subsequent response capabilities. When the power matching constraint is not met, it is determined whether the current energy storage state requires balance optimization, including whether the ratio of the flywheel's available kinetic energy to its rated kinetic energy is less than the first energy storage threshold, and whether the ratio of the gas storage tank pressure to its maximum operating pressure is less than the second energy storage threshold. When the energy storage balance constraint is met, a priority charging mode is determined based on the specific energy storage state; when all constraints are not met and the absolute value of the grid's demand power is less than a preset proportional threshold of the rated power, the standby mode is triggered by default.

[0073] In an optional implementation, the determination of safety constraints in step C1 can also introduce a multi-level safety early warning mechanism. For example, the safety status can be divided into three levels: normal, warning, and dangerous, based on the proximity of the gas tank pressure to the maximum working pressure. When the gas tank pressure reaches 90% of the maximum working pressure, the warning status is triggered and the charging power is reduced. When the gas tank pressure reaches 100% of the maximum working pressure, the dangerous status is triggered and the system is forcibly switched to the discharge mode. That is, the gradual response of safety constraints is achieved through graded early warning, avoiding drastic switching of system status.

[0074] In an optional implementation, the determination of the power matching constraint in step C3 can also be optimized by introducing a power margin coefficient. For example, when determining whether the power demand of the grid is greater than the upper limit of the flywheel's available power, the power margin coefficient α is multiplied, where the value of α ranges from 0.8 to 0.95. When the absolute value of the power demand of the grid is greater than the product of the upper limit of the flywheel's available power and the power margin coefficient, it is determined that the flywheel's response capability is exceeded. That is, by reserving a power margin, the system avoids frequent switching of operating modes in critical states, thereby improving the system's operational stability.

[0075] The steps to determine the system's operating mode include: When the safety constraints are met, the pressure of the gas storage tank is greater than the maximum working pressure of the gas storage tank, and the power demand of the power grid is less than zero, the system operating mode is determined to be the discharge compressed air independent response mode.

[0076] Specifically, when the pressure of the gas storage tank Greater than the maximum working pressure of the gas storage tank And the power demand of the power grid A value less than zero indicates a discharge demand, triggering the discharge compressed air independent response mode. In this mode, the first clutch CL1 is disengaged, the second clutch CL2 is engaged, the planetary carrier is locked, and the compressed air system outputs power to the grid independently. Simultaneously, the pressure in the air tank is reduced by releasing compressed air to eliminate the risk of overpressure.

[0077] When the safety constraints are met, the available kinetic energy of the flywheel is less than the minimum safe kinetic energy of the flywheel, and the power demand of the power grid is less than zero, the system operating mode is determined to be the discharge compressed air dominant mode.

[0078] Specifically, when the flywheel can utilize kinetic energy Less than the minimum safe kinetic energy of the flywheel And the power demand of the power grid A value less than zero indicates a discharge demand, triggering the compressed air-dominated discharge mode. In this mode, the second clutch CL2 engages, the first clutch CL1 is partially engaged and its torque is limited to less than or equal to 20% of the flywheel shaft's maximum torque. The compressed air system handles more than or equal to 80% of the output power, preventing the flywheel from over-discharging due to insufficient energy storage, thus avoiding safety risks.

[0079] When the fluctuation response constraint is met and the grid demand power is greater than zero, the system operating mode is determined to be the charging flywheel independent response mode.

[0080] Specifically, when the power grid fluctuation level is determined to be high-frequency fluctuation, and the power demand of the power grid... When a value greater than zero indicates a charging demand, the charging flywheel's independent response mode is triggered. In this mode, the first clutch CL1 is engaged, the second clutch CL2 is disengaged, the gear ring is locked, and the flywheel responds quickly and independently to the charging power demand, taking advantage of the flywheel's fast response speed to absorb power fluctuations on the grid side in a timely manner.

[0081] When the fluctuation response constraint is met and the power demand of the grid is less than zero, the system operating mode is determined to be the discharge flywheel independent response mode.

[0082] Specifically, when the power grid fluctuation level is determined to be high-frequency fluctuation, and the power demand of the power grid... A value less than zero indicates a discharge demand, triggering the flywheel's independent response mode. In this mode, the first clutch CL1 is engaged, the second clutch CL2 is disengaged, the gear ring is locked, and the flywheel independently and quickly responds to the discharge power demand, utilizing the flywheel's high power density to promptly output power to the grid and smooth out fluctuations.

[0083] When the power matching constraint is met and the grid demand power is greater than zero, the system operating mode is determined to be the charging hybrid mode.

[0084] Specifically, when the absolute value of the power demand from the power grid is simultaneously greater than both the upper limit of the flywheel's available power and the upper limit of the compressed air system's available power, and the power demand from the power grid... A value greater than zero indicates a charging demand, triggering the hybrid charging mode. In this mode, the first clutch CL1 and the second clutch CL2 are engaged, the planetary gear system is in a free state, and the charging is performed in the optimal ratio. The charging power is distributed to the flywheel and the air tank to achieve a coordinated response to high-power charging demands.

[0085] When the power matching constraint is met and the power demand of the grid is less than zero, the system operating mode is determined to be the discharge hybrid mode.

[0086] Specifically, when the absolute value of the power demand from the power grid is simultaneously greater than both the upper limit of the flywheel's available power and the upper limit of the compressed air system's available power, and the power demand from the power grid... A value less than zero indicates a discharge demand, triggering a hybrid discharge mode. In this mode, the first clutch CL1 and the second clutch CL2 are engaged, the planetary gear system is in a free state, and the power output of the flywheel and compressed air system is combined to the grid in an optimal ratio, achieving a coordinated response to high-power discharge demands.

[0087] When the energy storage balance constraint is met and the ratio of the available kinetic energy of the flywheel to the rated kinetic energy of the flywheel is less than the first energy storage threshold, the system operating mode is determined to be the charging flywheel priority mode.

[0088] Specifically, when the power demand of the power grid A value greater than zero indicates a charging demand and available kinetic energy for the flywheel. Less than the rated kinetic energy of the flywheel 50% of the gas storage tank pressure Less than the maximum working pressure of the gas storage tank When the charge reaches 50%, the flywheel priority charging mode is triggered. In this mode, the first clutch CL1 is engaged, the second clutch CL2 is disengaged, the gear ring is locked, and the flywheel is charged first. Because the flywheel charging efficiency is higher than that of the compressed air system, the overall charging efficiency of the system can be improved.

[0089] When the energy storage balance constraint is met and the ratio of the gas storage tank pressure to the maximum working pressure of the gas storage tank is less than the second energy storage threshold, the system operating mode is determined to be the charging compressed air priority mode.

[0090] Specifically, when the power demand of the power grid A value greater than zero indicates a charging demand, and the gas tank pressure... Less than the maximum working pressure of the gas storage tank 30% of the flywheel's kinetic energy is available. Greater than the rated kinetic energy of the flywheel When the energy level reaches 80%, the charging compressed air priority mode is triggered. In this mode, the first clutch CL1 is disengaged, the second clutch CL2 is engaged, the planetary carrier is locked, and the air tank is charged first to balance the energy distribution of the system and improve the subsequent high-power response capability.

[0091] When the absolute value of the power demand of the power grid is less than the preset proportional threshold of the rated power, the system operating mode is determined to be standby mode.

[0092] Specifically, when all constraints are not met, and the absolute value of the power demand of the grid is... Less than rated power When the power consumption is 0.5%, it indicates that there is no significant charging / discharging demand from the power grid, and the standby mode is triggered by default. In this mode, the first clutch CL1 and the second clutch CL2 are disconnected, the power converter is in standby mode, the planetary gear system is in a free state, the system operates with zero power consumption, reducing system energy consumption and extending equipment life.

[0093] In this embodiment of the application, S500 converts the system operating mode into a digital instruction and performs mode switching according to the digital instruction.

[0094] The steps for converting the system operating mode into digital instructions include D1~D2: D1. Convert the determined system operating mode into an 8-bit digital instruction according to the preset encoding rules. The first code corresponds to the charging flywheel priority mode, the second code corresponds to the charging compressed air priority mode, the third code corresponds to the charging hybrid mode, the fourth code corresponds to the discharging flywheel individual response mode, the fifth code corresponds to the discharging compressed air individual response mode, the sixth code corresponds to the discharging hybrid mode, and the seventh code corresponds to the standby mode.

[0095] Specifically, each operating mode is uniquely encoded using an 8-bit binary digital instruction. The encoding rules are as follows: charging flywheel priority mode corresponds to the first code 0001, charging compressed air priority mode corresponds to the second code 0010, charging mixed mode corresponds to the third code 0100, discharging flywheel single response mode corresponds to the fourth code 1001, discharging compressed air single response mode corresponds to the fifth code 1010, discharging mixed mode corresponds to the sixth code 1100, and standby mode corresponds to the seventh code 0000. In addition, the system also sets an emergency standby mode with the code 1111 for emergency protection in case of sensor failure or abnormal operating conditions. In the encoding rules, the high 4 bits are used to distinguish between charging and discharging modes, where 0 in the high 4 bits indicates charging or standby, and 1 in the high 4 bits indicates discharging; the low 4 bits are used to distinguish the specific operating mode type, enabling rapid identification and parsing of the operating mode.

[0096] D2. When outputting digital commands, a mode switching preparation signal is attached. The mode switching preparation signal is used to inform the switching control module to complete the pre-synchronization and torque gradual change preparation actions in advance.

[0097] The mode decision module outputs an 8-bit digital instruction along with a mode switching preparation signal. This signal is a separate 1-bit flag; a flag of 1 indicates an imminent mode switch, while a flag of 0 indicates maintaining the current mode. Upon receiving the mode switching preparation signal, the switching control module performs the following preparatory actions before the actual mode switch: pre-synchronization preparation includes calculating the target speed for clutch engagement based on the target mode, and adjusting the motor speed to ensure the speed difference between the components to be engaged is less than a preset threshold, thus avoiding impact during clutch engagement; torque gradual change preparation includes calculating the torque transition curve based on the target mode, and gradually adjusting the output torque according to an S-shaped or linear curve during mode switching to avoid mechanical shock and current fluctuations caused by sudden torque changes.

[0098] In an optional implementation, the encoding method of the digital instruction in step D1 can also adopt an extended encoding structure, such as extending the 8-bit digital instruction to 16 bits, where the high 8 bits are used to represent the working mode encoding and the low 8 bits are used to represent the additional parameter information for mode switching, including the target power level, switching speed level and priority identifier. That is, by extending the encoding structure, richer control information can be carried in a single instruction transmission, reducing the number of communication times between control modules and improving the response speed and control accuracy of mode switching.

[0099] In summary, by collecting multi-dimensional parameters and calculating the energy storage status assessment results, and combining a dual data processing mechanism of moving average filtering and median substitution, the power demand of the power grid is preprocessed. The power fluctuation level is determined based on the power change rate, and a four-level priority multi-constraint judgment logic of "safety constraints first, fluctuation response second, power matching third, and energy storage balance supplement" is established to achieve accurate matching of eight system operating modes. Through the output mechanism of 8-bit digital command encoding and mode switching preparation signals, the system can complete pre-synchronization and torque gradual change preparation actions in advance, thereby reducing mechanical shock and current fluctuations during mode switching.

[0100] Example 3 illustrates a schematic scheme for a control method of a bidirectional coupled flywheel and compressed air integrated energy storage system. It should be noted that the technical solution of this bidirectional coupled flywheel and compressed air integrated energy storage system control system belongs to the same concept as the technical solution of the aforementioned bidirectional coupled flywheel and compressed air integrated energy storage system control method. Details not described in detail in this embodiment can be found in the description of the aforementioned bidirectional coupled flywheel and compressed air integrated energy storage system control method.

[0101] This embodiment also provides a control system for a bidirectional coupled flywheel and compressed air integrated energy storage system, including: The parameter acquisition module is used to acquire multi-dimensional parameters and grid demand power of the bidirectional coupled flywheel and compressed air integrated energy storage system. The energy storage status calculation module is used to calculate the multi-dimensional parameters and form an energy storage status assessment result; The fluctuation determination module is used to filter the power demand of the power grid, calculate the power change rate through the filtered power demand, and determine the power fluctuation level based on the power change rate. The mode decision module is used to determine the system operating mode by performing multi-constraint judgment based on the energy storage status assessment results and the grid fluctuation level according to the priority order of multiple sets of constraints. The switching control module is used to convert the system's operating mode into digital instructions and perform mode switching according to the digital instructions.

[0102] This embodiment also provides an electronic device suitable for controlling a bidirectional coupled flywheel and compressed air integrated energy storage system, including: a memory and a processor; the memory is used to store computer-executable instructions, and the processor is used to execute the computer-executable instructions to realize the control method for the bidirectional coupled flywheel and compressed air integrated energy storage system proposed in the above embodiment.

[0103] This embodiment also provides a storage medium storing a computer program, which, when executed by a processor, implements the control method for an integrated bidirectional coupled flywheel and compressed air energy storage system as proposed in the above embodiments.

[0104] The storage medium proposed in this embodiment and the control method for realizing the integrated energy storage system of bidirectional coupled flywheel and compressed air proposed in the above embodiments belong to the same inventive concept. Technical details not described in detail in this embodiment can be found in the above embodiments, and this embodiment has the same beneficial effects as the above embodiments.

[0105] Based on the above description of the implementation methods, those skilled in the art can clearly understand that the present invention can be implemented using software and necessary general-purpose hardware, and of course, it can also be implemented using hardware. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as a computer floppy disk, read-only memory (ROM), random access memory (RAM), flash memory, hard disk, or optical disk, etc., including several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods of the various embodiments of the present invention.

[0106] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A control method for a bidirectional coupled flywheel and compressed air integrated energy storage system, characterized in that, Includes the following steps: Collect multi-dimensional parameters and grid demand power of the bidirectional coupled flywheel and compressed air integrated energy storage system; The multi-dimensional parameters are calculated to form an energy storage status assessment result; The power demand of the power grid is filtered, and the power change rate is calculated based on the filtered power demand. The power fluctuation level is then determined based on the power change rate. The energy storage status assessment results and grid fluctuation levels are used to determine the system operating mode by prioritizing multiple sets of constraints. The system's operating mode is converted into a digital instruction, and the mode switching is performed according to the digital instruction.

2. The control method for the bidirectional coupled flywheel and compressed air integrated energy storage system as described in claim 1, characterized in that, The steps for calculating the multi-dimensional parameters to form the energy storage state assessment results include: The available kinetic energy of the flywheel is calculated based on the flywheel moment of inertia and flywheel speed, which are parameters with multiple dimensions. The maximum usable power of the flywheel is calculated based on the maximum torque of the flywheel shaft and the flywheel speed, which are parameters of multiple dimensions. The compressed air energy of the storage tank is calculated based on multi-dimensional parameters such as storage tank pressure, storage tank volume, and specific heat ratio. The upper limit of the available power of the compressed air system is calculated based on multi-dimensional parameters such as expander adiabatic efficiency, air tank pressure, air tank volume, specific heat ratio, local atmospheric pressure and expander continuous working time. The available kinetic energy of the flywheel, the upper limit of the available power of the flywheel, the compressed air energy of the gas tank, and the upper limit of the available power of the compressed air system are output as the energy storage status assessment results.

3. The control method for the bidirectional coupled flywheel and compressed air integrated energy storage system as described in claim 2, characterized in that, The steps for filtering the power demand of the power grid include: Obtain the power demand of the power grid at the current sampling time and the power demand of the power grid at the previous two sampling times; The filtered power grid demand is obtained by summing the power grid demand at the current sampling time, the power grid demand at the previous sampling time, and the power grid demand at the previous two sampling times and taking the average value. The filtered grid demand power is compared with the grid demand power at the current sampling time. When the absolute value of the difference between the two is greater than a preset percentage of the rated power, the median of the grid demand power in the previous five sampling periods is used to replace the filtered grid demand power.

4. The control method for the bidirectional coupled flywheel and compressed air integrated energy storage system as described in claim 3, characterized in that, The steps of calculating the power change rate based on the filtered power demand and determining the power fluctuation level based on the power change rate include: Calculate the difference between the filtered power demand of the grid at the current sampling time and the filtered power demand of the grid at the previous sampling time, and divide the difference by the fixed sampling period to obtain the power change rate. Determine whether the absolute value of the power change rate is greater than a preset change rate threshold; When the absolute value of the power change rate is greater than the preset change rate threshold for two consecutive sampling periods, the power grid fluctuation level is determined to be high-frequency fluctuation. When the absolute value of the power change rate does not exceed the preset change rate threshold for two consecutive sampling periods, the power grid fluctuation level is determined to be non-high frequency fluctuation.

5. The control method for the bidirectional coupled flywheel and compressed air integrated energy storage system as described in claim 4, characterized in that, The steps for determining multiple constraints based on the energy storage status assessment results and grid fluctuation levels according to the priority order of multiple sets of constraints include: Determine whether the safety constraints are met. The safety constraints include the gas tank pressure being greater than the maximum working pressure of the gas tank or the flywheel's available kinetic energy being less than the flywheel's minimum safe kinetic energy. When the safety constraints are met, determine the system's operating mode based on the safety constraints. When the safety constraints are not met, it is determined whether the fluctuation response constraints are met. The fluctuation response constraints are that the power grid fluctuation level is high frequency fluctuation. When the fluctuation response constraints are met, the system operating mode is determined according to the fluctuation response constraints. When the fluctuation response constraint is not met, it is determined whether the power matching constraint is met. The power matching constraint is that the absolute value of the power demand of the power grid is greater than the upper limit of the available power of the flywheel and the upper limit of the available power of the compressed air system at the same time. When the power matching constraint is met, the system operating mode is determined according to the power matching constraint. When the power matching constraint is not met, determine whether the energy storage balance constraint is met, and determine the system operating mode based on the energy storage balance constraint or the default condition.

6. The control method for the bidirectional coupled flywheel and compressed air integrated energy storage system as described in claim 5, characterized in that, The steps to determine the system's operating mode include: When the safety constraints are met, the pressure of the gas storage tank is greater than the maximum working pressure of the gas storage tank, and the power demand of the power grid is less than zero, the system operating mode is determined to be the discharge compressed air independent response mode. When the safety constraints are met, the available kinetic energy of the flywheel is less than the minimum safe kinetic energy of the flywheel, and the power demand of the power grid is less than zero, the system operating mode is determined to be the discharge compressed air dominant mode. When the fluctuation response constraint is met and the grid demand power is greater than zero, the system operating mode is determined to be the charging flywheel independent response mode. When the fluctuation response constraint is met and the power demand of the grid is less than zero, the system operating mode is determined to be the discharge flywheel independent response mode. When the power matching constraint is met and the grid demand power is greater than zero, the system operating mode is determined to be the charging hybrid mode. When the power matching constraint is met and the grid demand power is less than zero, the system operating mode is determined to be the discharge hybrid mode. When the energy storage balance constraint is met and the ratio of the available kinetic energy of the flywheel to the rated kinetic energy of the flywheel is less than the first energy storage threshold, the system operating mode is determined to be the charging flywheel priority mode. When the energy storage balance constraint is met and the ratio of the gas storage tank pressure to the maximum working pressure of the gas storage tank is less than the second energy storage threshold, the system working mode is determined to be the charging compressed air priority mode. When the absolute value of the power demand of the power grid is less than the preset proportional threshold of the rated power, the system operating mode is determined to be standby mode.

7. The control method for the bidirectional coupled flywheel and compressed air integrated energy storage system as described in claim 6, characterized in that, The steps for converting the system operating mode into digital instructions include: The determined system operating mode is converted into an 8-bit digital instruction according to the preset encoding rules. The charging flywheel priority mode corresponds to the first code, the charging compressed air priority mode corresponds to the second code, the charging hybrid mode corresponds to the third code, the discharging flywheel single response mode corresponds to the fourth code, the discharging compressed air single response mode corresponds to the fifth code, the discharging hybrid mode corresponds to the sixth code, and the standby mode corresponds to the seventh code. When outputting digital commands, a mode switching preparation signal is attached. The mode switching preparation signal is used to inform the switching control module to complete the pre-synchronization and torque gradual change preparation actions in advance.

8. A control system for a bidirectional coupled flywheel and compressed air integrated energy storage system, using the method described in any one of claims 1-7, characterized in that, include: The parameter acquisition module is used to acquire multi-dimensional parameters and grid demand power of the bidirectional coupled flywheel and compressed air integrated energy storage system. The energy storage status calculation module is used to calculate the multi-dimensional parameters and form an energy storage status assessment result; The fluctuation determination module is used to filter the power demand of the power grid, calculate the power change rate through the filtered power demand, and determine the power fluctuation level based on the power change rate. The mode decision module is used to determine the system operating mode by performing multi-constraint judgment based on the energy storage status assessment results and the grid fluctuation level according to the priority order of multiple sets of constraints. The switching control module is used to convert the system's operating mode into digital instructions and perform mode switching according to the digital instructions.

9. An electronic device, comprising: Memory and processor; The memory is used to store computer-executable instructions, and the processor is used to execute the computer-executable instructions. When the computer-executable instructions are executed by the processor, they implement the steps of the control method for the bidirectional coupled flywheel and compressed air integrated energy storage system according to any one of claims 1 to 7.

10. A computer-readable storage medium storing computer-executable instructions that, when executed by a processor, implement the steps of the control method for the bidirectional coupled flywheel and compressed air integrated energy storage system according to any one of claims 1 to 7.

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