Flywheel energy storage fast charge-discharge execution system adaptive to power grid frequency modulation

Abstract

This invention discloses a flywheel energy storage fast charging and discharging execution system adapted to grid frequency regulation, specifically relating to the fields of power system automation and energy storage. The system includes a frequency detection module configured to acquire the voltage frequency at the flywheel grid connection point and calculate the frequency deviation; and a frequency regulation power command generation module coupled to the frequency detection module configured to generate a target power command based on the frequency deviation and an adjustable droop coefficient. The invention effectively solves the aforementioned problems by constructing a closed-loop control architecture integrating online grid strength identification, adaptive adjustment of control parameters, and power safety limiting. The system can actively inject small, non-affective detection signals into the grid and assess the short-circuit capacity level of the current connection point in real time by analyzing the grid's voltage response characteristics.

Description

Technical Field

[0001] This invention relates to the field of power system automation and energy storage, and more specifically, to a flywheel energy storage fast charging and discharging execution system adapted to power grid frequency regulation. Background Technology

[0002] In power grid frequency regulation applications, flywheel energy storage systems typically employ a droop control strategy. The core of this strategy is to generate corresponding active power regulation commands based on detected grid frequency deviations. Traditional solutions generally set the gain coefficient of droop control to a fixed value, often based on experience or offline calculations under specific grid conditions at the time of equipment commissioning. This static parameter configuration method can maintain basic functionality under relatively stable grid operating conditions and with minimal changes in short-circuit capacity. However, with the development of new power systems, the same flywheel energy storage device may need to be flexibly deployed or have its service targets switched between grid nodes in different geographical locations or operating states. The strength of these grid nodes, i.e., their short-circuit capacity, may vary significantly. Short-circuit capacity is a key indicator of the grid's ability to withstand power disturbances; it directly determines the fluctuation amplitude of grid voltage and frequency when the same power is injected or absorbed. When a flywheel system is transferred from a strong grid (high short-circuit capacity) environment to a weak grid (…),… In environments with low short-circuit capacity, if the existing high-gain droop coefficient optimized for strong power grids is continued, the system's response to frequency deviations will become overly sensitive. This will cause the flywheel to release or absorb excessive power in a small frequency disturbance, potentially amplifying grid oscillations and easily depleting its stored energy in a short time, thus losing its ability to continuously provide frequency regulation services. Conversely, using a low-gain coefficient designed for weak power grids in strong grids will make the flywheel's regulation effect weak, failing to effectively leverage its rapid response advantage and wasting equipment performance. Therefore, the core problem faced by existing technologies is that fixed droop control parameters cannot sense and adapt to dynamic changes in grid strength, leading to an irreconcilable contradiction between frequency regulation efficiency and operational safety when flywheel energy storage is applied across different scenarios. It is difficult to achieve optimal support under various grid conditions. To address this issue, a flywheel energy storage fast charge and discharge execution system adapted to grid frequency regulation is proposed. Summary of the Invention

[0003] To overcome the aforementioned deficiencies of existing technologies, this invention effectively solves the problems by constructing a closed-loop control architecture that integrates online grid strength identification, adaptive adjustment of control parameters, and power safety limiting. The system can proactively inject minute, non-disruptive detection signals into the grid and assess the short-circuit capacity level of the current access point in real time by analyzing the grid's voltage response characteristics. Based on this online assessment result, the system's internal mapping mechanism automatically selects a droop control gain coefficient that matches the current grid strength. In a weak grid environment, the system uses a smaller gain to suppress excessive power exchange, ensuring its own energy sustainability and grid stability. In a strong grid environment, a larger gain is used to fully utilize the flywheel's regulation potential and maximize its support for system frequency. Simultaneously, the power command is not executed directly after generation but undergoes dynamic verification and limiting based on an energy margin calculated from the flywheel's real-time rotational speed.

[0004] To achieve the above objectives, the present invention provides the following technical solution: a flywheel energy storage fast charging and discharging execution system adapted to grid frequency regulation, wherein a frequency detection module is configured to acquire the voltage frequency of the flywheel grid connection point and calculate the frequency deviation;

[0005] A frequency modulation power command generation module, coupled to the frequency detection module, is configured to generate a target power command based on the frequency deviation and an adjustable droop coefficient.

[0006] The droop control parameter adjustment module, coupled to the frequency modulation power command generation module, is configured to dynamically adjust the droop coefficient based on the online estimate of the grid short-circuit capacity, wherein the grid short-circuit capacity is estimated by injecting a small-amplitude test current into the grid and observing the change in the voltage amplitude at the grid connection point.

[0007] The power command limiting module, coupled to the frequency modulation power command generation module, is configured to trim the target power command to an upper and lower limit based on the energy storage state corresponding to the current speed of the flywheel, and generate a safe power command.

[0008] The flywheel operating status monitoring module is configured to collect flywheel speed, bearing temperature, vacuum degree and vibration signal in real time, and output derating or shutdown signal when any parameter exceeds the preset safety threshold;

[0009] A power execution module, coupled to the power command limiting module, is configured to receive the safe power command and drive the bidirectional flow of energy between the flywheel motor and the power grid.

[0010] The communication module is configured to upload the system's operating status and receive remote start / stop commands. The system's frequency control is entirely based on the local frequency signal and does not rely on power setting instructions issued by an external dispatch center.

[0011] In a preferred embodiment: the frequency detection module includes a voltage sensing unit for acquiring the grid connection point voltage signal, an analog-to-digital converter unit for converting the analog voltage signal into a digital signal, and a frequency calculation unit for calculating the grid frequency and its deviation from the rated frequency in real time based on the digital signal; wherein the frequency calculation unit is configured to achieve high-precision frequency tracking using a phase-locked loop algorithm or a spectrum analysis algorithm.

[0012] In a preferred embodiment: the frequency regulation power command generation module is configured to receive a frequency deviation signal from the frequency detection module, and, in conjunction with a dynamically adjustable droop control coefficient, generate a target active power command signal reflecting the frequency regulation requirements of the power grid through droop control logic.

[0013] In a preferred embodiment: the droop control parameter adjustment module includes an online grid impedance identification unit and a droop coefficient mapping unit; the online grid impedance identification unit is configured to inject a controllable small-amplitude current disturbance signal into the grid and simultaneously sample the voltage response signal at the grid connection point to estimate the short-circuit capacity index characterizing the grid strength online; the droop coefficient mapping unit is configured to find the corresponding droop control coefficient value from a preset correlation relationship based on the magnitude of the short-circuit capacity index and output it to the frequency modulation power command generation module.

[0014] In a preferred embodiment: the power command limiting module includes a flywheel energy storage status assessment unit and a dynamic limiting execution unit; the flywheel energy storage status assessment unit is configured to calculate the current available charge and discharge energy margin of the flywheel based on the real-time rotational speed signal output by the flywheel operation status monitoring module; the dynamic limiting execution unit is configured to generate, in real time, a matching upper limit threshold for charging power and a lower limit threshold for discharging power based on the energy margin, and use the thresholds to trim the target power command to form a safe power command that ensures the safe operation of the flywheel.

[0015] In a preferred embodiment: the flywheel operating status monitoring module includes a mechanical status sensor array and a status safety assessment unit; the mechanical status sensor array integrates a speed sensor for monitoring the flywheel rotor speed, a temperature sensor for monitoring the bearing operating temperature, a vacuum sensor for monitoring the vacuum chamber pressure, and a vibration sensor for monitoring the flywheel vibration level; the status safety assessment unit is configured to receive multi-dimensional status signals from the sensor array and compare them with their respective corresponding safe operating thresholds, and immediately generate and output a system derating operation command or an emergency shutdown protection command when any status signal exceeds its safety threshold.

[0016] In a preferred embodiment, the power execution module includes an outer-loop power controller for receiving a safe power command and generating a current reference signal, an inner-loop current controller for tracking the current reference signal and generating a pulse-width modulation drive signal, and a bidirectional four-quadrant converter composed of multiple power semiconductor switching devices. The bidirectional four-quadrant converter is connected between the flywheel motor and the power grid and is configured to precisely control the input or output power of the flywheel motor according to the pulse-width modulation drive signal, thereby realizing bidirectional, fast, and efficient energy flow between the flywheel and the power grid.

[0017] In a preferred embodiment: the communication module adopts a communication protocol conforming to power system automation standards and is configured to establish a data link with the upper-level dispatch center. It periodically uploads system operation data, including flywheel speed, state of charge, health status, and fault alarms, and receives system-level start / stop control commands from the dispatch center. The system's grid frequency regulation function is entirely based on locally sensed frequency signals and completes autonomous closed-loop operation without relying on any power setpoint instructions issued by the dispatch center.

[0018] The technical effects and advantages of this invention are as follows: This invention effectively solves the above-mentioned problems by constructing a closed-loop control architecture that integrates online grid strength identification, adaptive adjustment of control parameters, and power safety limiting. The system can actively inject small, non-affective detection signals into the grid and evaluate the short-circuit capacity level of the current access point in real time by analyzing the grid's voltage response characteristics. Based on this online evaluation result, the system's internal mapping mechanism automatically selects a droop control gain coefficient that matches the current grid strength. In a weak grid environment, the system uses a smaller gain to suppress excessive power exchange, ensuring its own energy sustainability and grid stability. In a strong grid environment, a larger gain is used to fully utilize the flywheel's regulation potential and maximize its support for system frequency. At the same time, the power command is not executed directly after generation, but undergoes dynamic verification and limiting based on the energy margin calculated from the flywheel's real-time rotational speed.

[0019] This process ensures that the power command issued at any time will not exceed the safety boundary allowed by the current physical state of the flywheel. Through the close cooperation of the three links of grid strength sensing, control parameter adaptation and power safety limiting, the present invention enables the flywheel energy storage system to autonomously find the best balance between frequency regulation performance and operational safety in grids of different strengths without human intervention, thereby achieving efficient and robust operation in variable grid environments. Attached Figure Description

[0020] Figure 1 This is a flowchart of the steps of the method of the present invention. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] An exemplary implementation will now be described more fully with reference to the accompanying drawings, a flywheel energy storage fast charge and discharge execution system adapted to grid frequency regulation: a frequency detection module is configured to acquire the voltage frequency at the flywheel grid connection point and calculate the frequency deviation;

[0023] A frequency modulation power command generation module, coupled to the frequency detection module, is configured to generate a target power command based on the frequency deviation and an adjustable droop coefficient.

[0024] The droop control parameter adjustment module, coupled to the frequency modulation power command generation module, is configured to dynamically adjust the droop coefficient based on the online estimate of the grid short-circuit capacity, wherein the grid short-circuit capacity is estimated by injecting a small-amplitude test current into the grid and observing the change in the voltage amplitude at the grid connection point.

[0025] The power command limiting module, coupled to the frequency modulation power command generation module, is configured to trim the target power command to an upper and lower limit based on the energy storage state corresponding to the current speed of the flywheel, and generate a safe power command.

[0026] The flywheel operating status monitoring module is configured to collect flywheel speed, bearing temperature, vacuum degree and vibration signal in real time, and output derating or shutdown signal when any parameter exceeds the preset safety threshold;

[0027] A power execution module, coupled to the power command limiting module, is configured to receive the safe power command and drive the bidirectional flow of energy between the flywheel motor and the power grid.

[0028] The communication module is configured to upload the system's operating status and receive remote start / stop commands. The system's frequency control is entirely based on local frequency signals and does not rely on power setting instructions issued by an external dispatch center. The frequency detection module includes a voltage sensing unit for acquiring grid connection point voltage signals, an analog-to-digital converter unit for converting analog voltage signals into digital signals, and a frequency calculation unit for calculating the grid frequency and its deviation from the rated frequency in real time based on the digital signals. The frequency calculation unit is configured to use a phase-locked loop algorithm or a spectrum analysis algorithm to achieve high-precision frequency tracking.

[0029] In a preferred embodiment of the present invention, the frequency detection module employs a Synchronous Reference Coordinate System Phase-Locked Loop (SRF-PLL) algorithm, the core calculation process of which is as follows:

[0030] First, the three-phase voltage of the power grid After Clark and Park transformations, the coordinates are transformed to the dq rotating coordinate system:

[0031]

[0032] in,

[0033] The voltage component along the d-axis.

[0034] The voltage component is the q-axis.

[0035] The phase angle estimated for the phase-locked loop;

[0036] Secondly, design a proportional-integral (PI) controller with respect to the q-axis voltage component. As input, the goal is to adjust it to zero;

[0037] The output of the PI controller is the estimated angular frequency.

[0038]

[0039] in,

[0040] For proportional gain,

[0041] For integral gain;

[0042] Finally, for Integrating to obtain the phase angle This is then fed back to the Park transformation matrix to form a closed loop; ultimately, the grid frequency... and its deviation It can be calculated using the following formula:

[0043]

[0044] in,

[0045] The rated frequency of the power grid is taken as 50Hz; For real-time power grid frequency;

[0046] This represents the frequency deviation.

[0047] The frequency regulation power command generation module is configured to receive a frequency deviation signal from the frequency detection module and, in conjunction with a dynamically adjustable droop control coefficient, generate a target active power command signal that reflects the frequency regulation requirements of the power grid through droop control logic.

[0048] The frequency modulation power command generation module adopts droop control logic, and its target active power command... Calculation

[0049] The formula is as follows:

[0050]

[0051] in, The target active power command is indicated by a positive value for discharging and a negative value for charging. This is the droop control factor, in MW / Hz; This is the power grid frequency deviation calculated by the frequency detection module.

[0052] The droop control parameter adjustment module includes an online grid impedance identification unit and a droop coefficient mapping unit. The online grid impedance identification unit is configured to inject a controllable small-amplitude current disturbance signal into the grid and simultaneously sample the voltage response signal at the grid connection point to estimate the short-circuit capacity index characterizing the grid strength online. The droop coefficient mapping unit is configured to find the corresponding droop control coefficient value from a preset correlation relationship based on the magnitude of the short-circuit capacity index and output it to the frequency modulation power command generation module.

[0053] The droop control parameter adjustment module dynamically adjusts the droop coefficient by online identification of the grid short-circuit capacity. Its workflow is as follows:

[0054] First, inject an amplitude of [value] into the power grid. The small sinusoidal current disturbance signal is sampled, and the voltage response signal at the grid connection point is sampled simultaneously to calculate its amplitude change. ;

[0055] Secondly, the short-circuit capacity of the power grid is estimated online using the following formula.

[0056]

[0057] in, This refers to the short-circuit capacity of the power grid, measured in MVA. This is the rated line voltage of the power grid, in kV. The change in voltage amplitude at the grid connection point after the disturbance is injected is expressed in kV. The value represents the injected disturbance current, in kA.

[0058] Finally, based on the estimated The value is used to determine a new droop control coefficient through a preset mapping relationship. ;

[0059] This mapping relationship can be represented as a piecewise function:

[0060]

[0061] in, The droop coefficient is a preset value, and it satisfies... and These are the short-circuit capacity thresholds for weak and strong power grids, respectively.

[0062] The power command limiting module includes a flywheel energy storage status assessment unit and a dynamic limiting execution unit. The flywheel energy storage status assessment unit is configured to calculate the current available charge and discharge energy margin of the flywheel based on the real-time rotational speed signal output by the flywheel operation status monitoring module. The dynamic limiting execution unit is configured to generate matching upper limit threshold for charging power and lower limit threshold for discharging power in real time based on the energy margin, and use the thresholds to trim the target power command to form a safe power command that ensures the safe operation of the flywheel.

[0063] The power command limiting module calculates the available energy margin based on the flywheel speed and dynamically generates the power limiting threshold accordingly.

[0064] The calculation process is as follows: First, based on the current speed of the flywheel... Calculate its stored kinetic energy :

[0065]

[0066] in,

[0067] The kinetic energy stored in the flywheel, measured in joules (J). The moment of inertia of the flywheel;

[0068] The current angular velocity of the flywheel, in rad / s;

[0069] Secondly, the safe operating speed range of the flywheel is defined as follows: Then its maximum release energy and maximum absorbable energy They are respectively:

[0070]

[0071]

[0072] in, The minimum safe speed for the flywheel, The maximum safe speed for the flywheel is set; finally, a time constant is determined. (e.g., 10 seconds), convert the energy margin into a power limiting threshold:

[0073]

[0074]

[0075] in, This is the upper limit of discharge power. This represents the lower limit of charging power.

[0076] Safe power command By issuing target power commands Obtained by cropping:

[0077] .

[0078] The flywheel operating status monitoring module includes a mechanical status sensor array and a status safety assessment unit. The mechanical status sensor array integrates a speed sensor for monitoring the flywheel rotor speed, a temperature sensor for monitoring the bearing operating temperature, a vacuum sensor for monitoring the vacuum chamber pressure, and a vibration sensor for monitoring the flywheel vibration level. The status safety assessment unit is configured to receive multi-dimensional status signals from the sensor array and compare them with their respective corresponding safe operating thresholds. When any status signal exceeds its safety threshold, it immediately generates and outputs a system derating operation command or an emergency shutdown protection command.

[0079] In a preferred embodiment of the present invention, the power execution module employs a dual-closed-loop vector control strategy. Its inner-loop current controller uses a PI regulator, and its output is the voltage reference values ​​for the d-axis and q-axis.

[0080]

[0081] in, and These are the proportional and integral gains of the current loop PI controller, respectively.

[0082] The current reference values ​​for the d-axis and q-axis are determined by the outer loop power controller based on... Calculated;

[0083] These are the measured d-axis and q-axis currents;

[0084] The inductances of the motor's d-axis and q-axis;

[0085] For permanent magnet flux linkage;

[0086] This is the electric angular velocity of the motor.

[0087] The above voltage reference value After inverse Park transformation, the reference values ​​of the αβ axis voltages in the stationary coordinate system are obtained.

[0088]

[0089] in, The rotor electrical angle is obtained from the phase-locked loop or position sensor;

[0090] Then, The input is fed to the Space Vector Pulse Width Modulation (SVPWM) unit.

[0091] The power execution module includes an outer-loop power controller for receiving a safe power command and generating a current reference signal, an inner-loop current controller for tracking the current reference signal and generating a pulse-width modulation drive signal, and a bidirectional four-quadrant converter composed of multiple power semiconductor switching devices. The bidirectional four-quadrant converter is connected between the flywheel motor and the power grid and is configured to precisely control the input or output power of the flywheel motor according to the pulse-width modulation drive signal, thereby realizing bidirectional, fast, and efficient energy flow between the flywheel and the power grid.

[0092] The flywheel operating status monitoring module performs safety assessments through multi-sensor fusion.

[0093] Its core criterion is a set of inequalities:

[0094]

[0095] in, Let t be the real-time angular velocity of the flywheel at time t;

[0096] and These are the preset minimum and maximum safe speed thresholds, respectively;

[0097] Let t be the bearing temperature.

[0098] This is the upper limit of the bearing's safe temperature.

[0099] Let t be the pressure in the vacuum chamber.

[0100] This represents the upper limit of vacuum safety.

[0101] The effective value of the vibration velocity at time t;

[0102] This is the upper limit for vibration safety.

[0103] If any of the above inequalities are not true, the state safety assessment unit immediately outputs an emergency shutdown command.

[0104] The communication module adopts a communication protocol compliant with power system automation standards and is configured to establish a data link with the upper-level dispatch center. It periodically uploads system operation data, including flywheel speed, state of charge, health status, and fault alarms, and receives system-level start / stop control commands from the dispatch center. The system's grid frequency regulation function is entirely based on locally sensed frequency signals and completes autonomous closed-loop operation without relying on any power setpoint instructions issued by the dispatch center. The communication module uses the IEC61850-9-2 protocol for data interaction.

[0105] The state of charge (SOC) of the flywheel uploaded is calculated by the following formula:

[0106]

[0107] in, The state of charge of the flywheel energy storage system is expressed as a percentage; the meanings of the other symbols are the same as above.

[0108] This module will periodically The status, ω, health status (SOH), and fault codes are packaged into a GOOSE message and uploaded to the superior dispatch center.

[0109] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A flywheel energy storage rapid charging and discharging execution system adapted to power grid frequency regulation, characterized in that, include: The frequency detection module is configured to acquire the voltage frequency at the flywheel grid connection point and calculate the frequency deviation; A frequency modulation power command generation module, coupled to the frequency detection module, is configured to generate a target power command based on the frequency deviation and an adjustable droop coefficient. The droop control parameter adjustment module, coupled to the frequency modulation power command generation module, is configured to dynamically adjust the droop coefficient based on the online estimate of the grid short-circuit capacity, wherein the grid short-circuit capacity is estimated by injecting a small-amplitude test current into the grid and observing the change in the voltage amplitude at the grid connection point. The power command limiting module, coupled to the frequency modulation power command generation module, is configured to trim the target power command to an upper and lower limit based on the energy storage state corresponding to the current speed of the flywheel, and generate a safe power command. The flywheel operating status monitoring module is configured to collect flywheel speed, bearing temperature, vacuum degree and vibration signal in real time, and output derating or shutdown signal when any parameter exceeds the preset safety threshold; A power execution module, coupled to the power command limiting module, is configured to receive the safe power command and drive the bidirectional flow of energy between the flywheel motor and the power grid. The communication module is configured to upload the system's operating status and receive remote start / stop commands. The system's frequency control is entirely based on the local frequency signal and does not rely on power setting instructions issued by an external dispatch center.

2. A flywheel energy storage rapid charging and discharging execution system adapted to power grid frequency regulation according to claim 1, characterized in that, The frequency detection module includes a voltage sensing unit for acquiring voltage signals at the grid connection point, an analog-to-digital converter unit for converting analog voltage signals into digital signals, and a frequency calculation unit for calculating the grid frequency and its deviation from the rated frequency in real time based on the digital signals; wherein, the frequency calculation unit is configured to achieve high-precision frequency tracking using a phase-locked loop algorithm or a spectrum analysis algorithm.

3. A flywheel energy storage rapid charging and discharging execution system adapted to power grid frequency regulation according to claim 1, characterized in that, The frequency regulation power command generation module is configured to receive a frequency deviation signal from the frequency detection module and, in conjunction with a dynamically adjustable droop control coefficient, generate a target active power command signal that reflects the frequency regulation requirements of the power grid through droop control logic.

4. A flywheel energy storage rapid charging and discharging execution system adapted to power grid frequency regulation according to claim 1, characterized in that, The droop control parameter adjustment module includes an online grid impedance identification unit and a droop coefficient mapping unit; the online grid impedance identification unit is configured to inject a controllable small-amplitude current disturbance signal into the grid and simultaneously sample the voltage response signal at the grid connection point to estimate the short-circuit capacity index characterizing the grid strength online. The droop coefficient mapping unit is configured to find the corresponding droop control coefficient value from a preset correlation based on the magnitude of the short-circuit capacity index, and output it to the frequency modulation power command generation module.

5. A flywheel energy storage rapid charging and discharging execution system adapted to power grid frequency regulation according to claim 1, characterized in that, The power command limiting module includes a flywheel energy storage status assessment unit and a dynamic limiting execution unit; the flywheel energy storage status assessment unit is configured to calculate the current available charge and discharge energy margin of the flywheel based on the real-time speed signal output by the flywheel operation status monitoring module. The dynamic limiting execution unit is configured to generate, in real time, a matching upper limit threshold for charging power and a lower limit threshold for discharging power based on the energy margin, and to use the thresholds to prune the target power command to form a safe power command that ensures the safe operation of the flywheel.

6. A flywheel energy storage rapid charging and discharging execution system adapted to power grid frequency regulation according to claim 1, characterized in that, The flywheel operating status monitoring module includes a mechanical status sensor array and a status safety assessment unit. The mechanical status sensor array integrates a speed sensor for monitoring the flywheel rotor speed, a temperature sensor for monitoring the bearing operating temperature, a vacuum sensor for monitoring the vacuum chamber pressure, and a vibration sensor for monitoring the flywheel vibration level. The status safety assessment unit is configured to receive multi-dimensional status signals from the sensor array and compare them with their respective corresponding safe operating thresholds. When any status signal exceeds its safety threshold, it immediately generates and outputs a system derating operation command or an emergency shutdown protection command.

7. A flywheel energy storage rapid charging and discharging execution system adapted to power grid frequency regulation according to claim 1, characterized in that, The power execution module includes an outer-loop power controller for receiving a safe power command and generating a current reference signal, an inner-loop current controller for tracking the current reference signal and generating a pulse-width modulation drive signal, and a bidirectional four-quadrant converter composed of multiple power semiconductor switching devices. The bidirectional four-quadrant converter is connected between the flywheel motor and the power grid and is configured to precisely control the input or output power of the flywheel motor according to the pulse-width modulation drive signal, thereby realizing bidirectional, fast, and efficient energy flow between the flywheel and the power grid.

8. A flywheel energy storage rapid charging and discharging execution system adapted to power grid frequency regulation according to claim 1, characterized in that, The communication module adopts a communication protocol that conforms to the power system automation standard and is configured to establish a data link with the upper-level dispatch center. It is used to periodically upload system operation data, including flywheel speed, state of charge, health status and fault alarms, and to receive system-level start and stop control commands from the dispatch center. The grid frequency regulation function of the system is completed autonomously in a closed loop based entirely on locally sensed frequency signals, without relying on any power setpoint instructions issued by the dispatch center.

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