Flywheel energy storage array cooperative control method and flywheel energy storage array system

Abstract

The invention provides a flywheel energy storage array cooperative control method and a flywheel energy storage array system.The control method adopts a layered power distribution strategy for power distribution, and the control method comprises the following steps that S1, a state estimator calculates and estimates state parameters of all flywheel units in the flywheel energy storage array system in real time; s2, performing upper-layer sorting on flywheel energy storage arrays in the flywheel energy storage array system according to the average residual electric quantity in the state parameters, and sequentially selecting the flywheel energy storage arrays as a priority power distribution target to perform power distribution according to the magnitude of the average residual electric quantity deviating from the overall average value of the flywheel energy storage array system; s3, in the flywheel energy storage array serving as the priority power distribution target, calculating a lower-layer power distribution value according to the maximum power proportion of each flywheel unit, and distributing power to the corresponding flywheel; and S4, repeating the steps S2 to S3 until the power requirement of the flywheel energy storage array system is met. And the overall performance of the flywheel energy storage array can be obviously improved.

Description

Technical Field

[0001] The present invention relates to the technical field of flywheel energy storage, and particularly to a cooperative control method for a flywheel energy storage array and a flywheel energy storage array system. Background Art

[0002] In order to obtain a larger energy storage capacity, higher power, and longer backup time, a single-function flywheel energy storage device is difficult to meet the energy storage requirements in a wide power range due to cost and technical limitations, which will restrict the popularization and application of flywheel energy storage technology. Therefore, connecting multiple flywheel energy storage units in parallel to form a flywheel energy storage array system can improve the power and energy storage capacity of the entire flywheel energy storage system.

[0003] The coordinated control strategy of the flywheel energy storage array mainly studies the power distribution strategy among the units, solves the power distribution problem by coordinating the output power of each flywheel unit, and designs control algorithms for different requirements according to different constraints. The frequency fluctuation of the power grid is essentially caused by power imbalance. Therefore, the control objective of the flywheel energy storage array is to enable the output power of the system to track the power command in real time and accurately. Existing power distribution strategies have defects. For example, equal power distribution will increase the difference in the SOC (state of charge) of the flywheels, affecting the overall output power; proportional distribution will cause the power allocated to the units to exceed the limit under certain circumstances; traditional centralized control is vulnerable to single-point failures. These problems restrict the efficient application of flywheel energy storage technology.

[0004] In view of this, the inventors of the present application have designed a cooperative control method for a flywheel energy storage array and a flywheel energy storage array system in order to overcome the above technical problems. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a cooperative control method for a flywheel energy storage array and a flywheel energy storage array system in order to overcome the defects in the prior art that equal power distribution will increase the difference in the SOC (state of charge) of the flywheels, affecting the overall output power, proportional distribution will cause the power allocated to the units to exceed the limit under certain circumstances, and traditional centralized control is vulnerable to single-point failures.

[0006] The present invention solves the above technical problems through the following technical solutions:

[0007] The present invention provides a cooperative control method for a flywheel energy storage array, characterized in that the control method uses a hierarchical power distribution strategy for power distribution, and the control method includes the following steps: Step S 1 The state estimator calculates and estimates the state parameters of each flywheel unit in the flywheel energy storage array system in real time; Step S 2, perform upper-level sorting on each flywheel energy storage array in the flywheel energy storage array system according to the average remaining power in the state parameters, and select flywheel energy storage arrays in sequence according to the magnitude of the deviation of the average remaining power from the overall average value of the flywheel energy storage array system as the priority power distribution targets for power distribution; step S 3 , within the flywheel energy storage array serving as the priority power distribution target, calculate the lower-level power distribution value according to the maximum power ratio of each flywheel unit, and distribute the power to the corresponding flywheel; step S 4 , repeat the said step S 2 to the said step S 3 until the power demand of the flywheel energy storage array system is met.

[0008] According to one or more embodiments of the present invention, the state estimator adopts a fixed-time estimator based on the dynamic average consensus algorithm. The fixed-time estimator has a convergence time upper limit independent of the initial state, and can converge in a short time when the state parameters of the flywheels vary greatly, reducing the influence of the estimation error on the final control effect.

[0009] According to one or more embodiments of the present invention, the said step S 2 Sort from largest to smallest according to the average remaining power value of each flywheel energy storage array, judge the charge and discharge directions according to the frequency modulation power command of the flywheel energy storage array system, and distribute power to the flywheel energy storage arrays according to the sorting result of the average remaining power; the said step S 3 Distribute power to the flywheel units under each flywheel energy storage array according to the maximum output ratio principle according to the array power command allocated to the flywheel energy storage array.

[0010] According to one or more embodiments of the present invention, the power distribution of the flywheel energy storage array is carried out according to the charge and discharge directions: during charging, start the distribution from the flywheel energy storage array with the lowest average remaining power, compare the array power command with the maximum charging power of the flywheel energy storage array. If the array power command is greater than the maximum power, set the reference charging power equal to the maximum power and update the remaining array power command; if the array power command is less than the maximum power, set the reference charging power equal to the command and set the remaining array power command to 0; during discharging, start the distribution from the flywheel energy storage array with the highest average remaining power, compare the array power command with the maximum discharging power of the flywheel energy storage array. If the array power command is less than or equal to the maximum power, set the reference discharging power equal to the maximum power and update the remaining array power command; if the array power command is greater than the maximum power, set the reference discharging power equal to the command and set the remaining array power command to 0; until the power command distribution is completed or all flywheels are allocated non-zero power commands.

[0011] The present invention also provides a flywheel energy storage array system, characterized in that the flywheel energy storage array system is controlled by using the flywheel energy storage array cooperative control method as described above. The flywheel energy storage array system includes a plurality of flywheel energy storage arrays, and each flywheel energy storage array includes a plurality of flywheel units; each flywheel unit includes a flywheel controller; each flywheel energy storage array is configured with an array controller, and the array controller is electrically connected or communicatively connected to the flywheel controllers of each flywheel unit in the flywheel energy storage array where it is located; the flywheel energy storage array system is configured with a group controller, and the group controller is electrically connected or communicatively connected to each array controller.

[0012] According to one or more embodiments of the present invention, the flywheel unit further includes a motor, a flywheel, and a bidirectional converter.

[0013] According to one or more embodiments of the present invention, the flywheel energy storage array system is controlled by using a fully distributed control algorithm. The flywheel energy storage array system further includes a state estimator and a power estimator. The state estimator is used to calculate and estimate the global average state information, and the power estimator is used to calculate and estimate the average power.

[0014] According to one or more embodiments of the present invention, the state parameters of each flywheel unit are transmitted between the flywheel controllers. The state parameters of the flywheel unit include: flywheel speed, flywheel unit power, and flywheel torque.

[0015] According to one or more embodiments of the present invention, the group controller is used to perform upper-layer sorting on each flywheel energy storage array in the flywheel energy storage array system according to the average remaining power in the state parameters, and sequentially select the flywheel energy storage array with the average remaining power deviating from the overall average value of the flywheel energy storage array system as the priority power distribution target for power distribution; the array controller is used to calculate the lower-layer power distribution value according to the maximum power ratio of each flywheel unit in the flywheel energy storage array as the priority power distribution target, and distribute the power to the corresponding flywheel.

[0016] According to one or more embodiments of the present invention, the group controller is used to obtain the flywheel array power and flywheel array power information in the array controller, and transmit an array power command to the array controller; the array controller is used to obtain the flywheel speed, flywheel unit power, and flywheel unit power information in the flywheel controller, and transmit a flywheel power command to the flywheel controller.

[0017] According to one or more embodiments of the present invention, each flywheel controller is communicatively connected to a communication unit, and the communication units in the flywheel energy storage array system are communicatively connected to each other to form a communication network.

[0018] The positive and progressive effects of the present invention are as follows:

[0019] The collaborative control method of the flywheel energy storage array based on power distribution of the present invention has the following advantages:

[0020] First, it can improve the maximum charge-discharge power of the array: The collaborative control method of the flywheel energy storage array of the present invention can coordinate the flywheel SOC (state of charge) when responding to the power command, avoiding the problem of power reduction caused by excessive SOC (state of charge) difference, thereby improving the overall maximum charge-discharge power of the array.

[0021] Second, it can adapt to different power commands: During the operation of the flywheel energy storage array system of the present invention, the power commands are sorted and distributed according to the average SOC (state of charge), and can be reasonably distributed to the flywheel energy storage arrays with different SOC (state of charge) according to the magnitude and direction of the power commands, effectively adjusting the remaining charge of the array, and further improving the adaptability and stability of the system to different power demands.

[0022] Third, it reduces the number of operations and balances the SOC (state of charge): By reasonably arranging the charge-discharge sequence and power distribution of the flywheel energy storage array, the number of charge-discharge operations of the flywheel array is reduced, and at the same time, the balance of the SOC (state of charge) between the flywheel energy storage arrays is maintained, extending the service life of the flywheel energy storage array system. Description of the Drawings

[0023] The above and other features, properties, and advantages of the present invention will become more apparent from the following description in conjunction with the drawings and embodiments, where the same reference numerals in the drawings always represent the same features, wherein:

[0024] Figure 1 is a schematic model diagram of the flywheel energy storage array system of the present invention.

[0025] Figure 2 is a schematic diagram of the hierarchical control structure of the flywheel energy storage array system of the present invention.

[0026] Figure 3 is a schematic diagram of the structure of the flywheel energy storage array system of the present invention. Detailed Embodiments

[0027] To make the above objects, features, and advantages of the present invention more obvious and understandable, the following detailed description of the specific embodiments of the present invention is provided in conjunction with the drawings.

[0028] Embodiments of the present invention will now be described in detail with reference to the accompanying drawings. Preferred embodiments of the present invention will now be described in detail, and examples thereof are shown in the accompanying drawings. Whenever possible, the same reference numerals will be used throughout the drawings to represent the same or similar parts. In addition, although the terms used in the present invention are selected from well-known and commonly used terms, some of the terms mentioned in the description of the present invention may be selected by the applicant according to his or her judgment, and the detailed meanings thereof are described in the relevant parts of the description herein. In addition, it is required to understand the present invention not only by the actual terms used, but also by the meanings implied by each term. At the same time, for the sake of convenience of description, the dimensions of the various parts shown in the accompanying drawings are not drawn in actual proportional relationship.

[0029] See Figure 2 - Figure 3 , the present invention provides a cooperative control method for a flywheel energy storage array. The control method uses a hierarchical power distribution strategy for power distribution, and the control method includes the following steps:

[0030] Step S 1 , a state estimator calculates in real time the state parameters of each flywheel unit in the flywheel energy storage array system;

[0031] Step S 2 , perform upper-layer sorting on each flywheel energy storage array in the flywheel energy storage array system according to the average remaining power in the state parameters, and select the flywheel energy storage array as the priority power distribution target for power distribution in sequence according to the magnitude of the deviation of the average remaining power from the overall average value of the flywheel energy storage array system;

[0032] Step S 3 , within the flywheel energy storage array serving as the priority power distribution target, calculate the lower-layer power distribution value according to the maximum power ratio of each flywheel unit, and distribute the power to the corresponding flywheel;

[0033] Step S 4 , repeat the said Step S 2 to the said Step S 3 until the power demand of the flywheel energy storage array system is met.

[0034] It should be noted that for the cooperative control method of the flywheel energy storage array of the present invention, a distributed power distribution scheme is adopted, a state estimator is used, and for the flywheel energy storage array system, a hierarchical power distribution method is adopted. The upper layer selects the priority array according to the average remaining power of the array, and the lower layer distributes the power to the flywheel according to the maximum power ratio.

[0035] The flywheel energy storage array system consists of multiple flywheel energy storage arrays, and each flywheel energy storage array contains several flywheel units. Considering the power characteristics of individual flywheel units, the upper layer sorts according to the average remaining power of each flywheel energy storage array, and sequentially selects the priority arrays according to the charge and discharge requirements to undertake the load of the total power command with the maximum power. The lower layer distributes power to each flywheel unit according to the proportion of the maximum power to improve the power tracking performance of the group, reduce the number of charge and discharge actions of the arrays, and adjust the power balance between the arrays.

[0036] As a preferred embodiment of the collaborative control method for flywheel energy storage arrays based on power distribution of the present invention, the state estimator adopts a fixed-time estimator based on the dynamic average consensus algorithm. The fixed-time estimator has an upper limit of the convergence time independent of the initial state, and can converge in a short time when the state parameters of the flywheels are quite different, reducing the influence of the estimation error on the final control effect.

[0037] It should be noted that by selecting a fixed-time estimator based on the dynamic average consensus algorithm as the state estimator, the global state parameters changing with time are tracked and estimated.

[0038] As a preferred embodiment of the collaborative control method for flywheel energy storage arrays based on power distribution of the present invention, the step S 2 Sort from large to small according to the average SOC (remaining power) value of each flywheel energy storage array, judge the charge and discharge direction according to the frequency modulation power command of the flywheel energy storage array system, and distribute power to the flywheel energy storage arrays according to the sorting result of the average SOC (remaining power);

[0039] The step S 3 Distribute power to the flywheel units under each flywheel energy storage array according to the maximum output proportion principle according to the array power command allocated to the flywheel energy storage array.

[0040] As a preferred embodiment of the collaborative control method for flywheel energy storage arrays of the present invention, the power distribution of the flywheel energy storage arrays is carried out according to the charge and discharge direction:

[0041] During charging, start distributing from the flywheel energy storage array with the lowest average SOC (remaining power) value. Compare the array power command with the maximum charging power of the flywheel energy storage array. If the array power command is greater than the maximum power, set the reference charging power equal to the maximum power and update the remaining array power command; if the array power command is less than the maximum power, set the reference charging power equal to the command and set the remaining array power command to 0;

[0042] During discharge, start the allocation from the flywheel energy storage array with the highest average SOC (state of charge) value. Compare the array power command with the maximum discharge power of the flywheel energy storage array. If the array power command is less than or equal to the maximum power, set the reference discharge power equal to the maximum power and perform the update of the remaining array power command. If the array power command is greater than the maximum power, set the reference discharge power equal to the command and set the remaining array power command to 0.

[0043] Until the power command allocation is completed or all flywheels are allocated non-zero power commands.

[0044] As described above, the array power allocation performs power allocation according to the SOC (state of charge) sorting result and the positive and negative values of the power command. Dynamically allocating power based on the SOC (state of charge) sorting and power command can preferentially charge and discharge the unit with the optimal efficiency, balance the SOC (state of charge) status of each flywheel in the array, and improve the overall response speed and energy utilization rate.

[0045] The present invention determines the charge and discharge direction based on the flywheel group frequency modulation power command. It should be noted that the flywheel group frequency modulation power command refers to the control signal sent by the power system to the flywheel energy storage system, that is, the flywheel group, according to the change of the grid frequency to adjust its charge and discharge power.

[0046] When the grid frequency fluctuates, the system will calculate the magnitude and direction (charge or discharge) of the frequency modulation power required by the flywheel energy storage array system according to the pre-set frequency modulation strategy and algorithm, and send the corresponding command to the flywheel energy storage array system. After receiving the command, the flywheel energy storage array system quickly responds and adjusts the charge and discharge power by controlling the operating state of the motor to achieve the regulation of the grid frequency and maintain the stability of the grid frequency. For example, when the grid frequency decreases, the command will require the flywheel energy storage array system to inject active power into the grid to increase the grid frequency; conversely, when the grid frequency is too high, the command will cause the flywheel energy storage array system to charge and absorb the excess power in the grid to reduce the frequency to the normal range.

[0047] As described above, the collaborative control method of the flywheel energy storage array can solve the problems of unreasonable power distribution and poor system stability in the prior art through the improved coordinated control strategy of the flywheel energy storage array, and improve the overall performance of the flywheel energy storage array.

[0048] See Figure 2 - Figure 3 , the present invention also provides a flywheel energy storage array system, and the flywheel energy storage array system is controlled by using the collaborative control method of the flywheel energy storage array as described above.

[0049] The flywheel energy storage array system includes a plurality of flywheel energy storage arrays, and each flywheel energy storage array includes a plurality of flywheel units.

[0050] Each of the flywheel units includes a flywheel controller;

[0051] Each of the flywheel energy storage arrays is configured with an array controller, and the array controller is electrically connected or communicatively connected to the flywheel controllers of each of the flywheel units in the flywheel energy storage array where it is located;

[0052] The flywheel energy storage array system is configured with a group controller, and the group controller is electrically connected or communicatively connected to each array controller.

[0053] Equipping each flywheel unit with a flywheel controller and setting a group controller and an array controller can achieve a hierarchical control function.

[0054] As Figure 2 shown, the flywheel energy storage array system of the present invention adopts a hierarchical control structure, where the first layer is the group controller, which is responsible for collecting the real-time parameters of each flywheel energy storage array and calculating the power output value of each array; the second layer is the array controller, which calculates the power output value of each flywheel unit according to the real-time parameters of the flywheel units within the flywheel energy storage array.

[0055] As Figure 3 shown, the flywheel energy storage array system of the present invention preferably consists of N flywheel arrays, and there are M flywheel units inside each flywheel array. Since the flywheel is often used as an auxiliary power output device to provide power support for the power generation side, the requirements for the flywheel group are to be able to respond quickly, be able to meet the charge and discharge requirements, adjust the power balance, and reduce the number of operations within a certain period of time.

[0056] Preferably, N flywheel energy storage arrays are provided in the flywheel energy storage array system, and M flywheel units are provided in each flywheel energy storage array. Correspondingly, N array controllers are configured, and each array controller is electrically connected or communicatively connected to the group controller. Each of the M flywheel units in each flywheel energy storage array includes a flywheel controller, for a total of M flywheel controllers, and each flywheel controller is electrically connected or communicatively connected to the array controller.

[0057] The flywheel energy storage array system of the present invention designs a distributed scheme for each flywheel unit. The flywheel energy storage array system consists of N flywheel energy storage arrays. Each flywheel unit has its own flywheel controller, and the flywheel controller is preferably a distributed controller, capable of communicating with the information of adjacent flywheel units.

[0058] The change of the SOC (remaining charge) of the flywheel is specified in both the charging and discharging modes, so that the change rate of the SOC (remaining charge) of each flywheel unit is related to its current SOC (remaining charge).

[0059] During the operation of the flywheel energy storage array system of the present invention, power commands can be sorted and distributed according to the average SOC (State of Charge), and rationally distributed to arrays with different SOCs according to the magnitude and direction of the power commands, so as to effectively regulate the remaining power of the flywheel energy storage array.

[0060] See Figure 1 , as a preferred embodiment of the flywheel energy storage array system of the present invention, the flywheel unit further includes a motor, a flywheel, and a bidirectional converter.

[0061] In the charging stage, the bidirectional converter rectifies the alternating current into direct current, drives the motor to accelerate the rotation of the flywheel, and stores the electric energy as kinetic energy; in the discharging stage, the kinetic energy released by decelerating the flywheel is converted into direct current through a generator and then inverted into alternating current to be fed back to the power grid or used by the load.

[0062] See Figure 1 , as a preferred embodiment of the flywheel energy storage array system of the present invention, the flywheel energy storage array system is controlled by an all-distributed control algorithm. The flywheel energy storage array system further includes a state estimator and a power estimator. The state estimator is used to calculate and estimate the global average state information, and the power estimator is used to calculate and estimate the average power.

[0063] By adopting an all-distributed control algorithm, a global state information estimator and a power estimator are designed to estimate the global average state information and the average power.

[0064] As a preferred embodiment of the flywheel energy storage array system of the present invention, the state parameters of each flywheel unit are transmitted between the flywheel controllers. The state parameters of the flywheel unit include: flywheel speed, flywheel unit power, and flywheel torque.

[0065] The parameters exchanged between the flywheel controllers include, but are not limited to, speed, power, torque, etc., and can realize information intercommunication and coordinated control.

[0066] As a preferred embodiment of the flywheel energy storage array system of the present invention, the group controller is used to perform upper-level sorting on each flywheel energy storage array in the flywheel energy storage array system according to the average remaining power in the state parameters, and select the flywheel energy storage array as the priority power distribution target for power distribution in sequence according to the magnitude of the deviation of the average remaining power from the overall average value of the flywheel energy storage array system;

[0067] The array controller is used to calculate the lower-level power distribution value according to the maximum power ratio of each flywheel unit within the flywheel energy storage array as the priority power distribution target, and distribute the power to the corresponding flywheel.

[0068] See Figure 2, as a preferred embodiment of the flywheel energy storage array system of the present invention, the group controller is used to obtain the power and power information of the flywheel array in the array controller, and transmit the array power command P to the array controller. 1 -P N ; The array controller is used to obtain the flywheel speed, flywheel unit power and flywheel unit power information in the flywheel controller, and transmit the flywheel power command P to the flywheel controller.

[0069] Figure 2 The flywheel energy storage array system in adopts a hierarchical control structure, where the first layer is the group controller, whose main function is to collect the real-time parameters of each flywheel energy storage array, including but not limited to speed, power, torque, etc., and calculate the power output value of each array based on these collected parameters. The second layer is the array controller, which calculates the power output value of each flywheel unit according to the real-time parameters of the flywheel units in the flywheel energy storage array.

[0070] See Figure 1 , as a preferred embodiment of the flywheel energy storage array system of the present invention, each flywheel controller is communicatively connected to a communication unit, and the communication units in the flywheel energy storage array system are communicatively connected to each other to form a communication network.

[0071] Figure 1 In , there are Z flywheel units including flywheel unit 1, 2... Z, and correspondingly Z flywheel controllers including flywheel controller 1, 2... Z, and Z communication units including communication unit 1, 2... Z; among them, flywheel controller 1 is communicatively connected to communication unit 1, flywheel controller 2 is communicatively connected to communication unit 2, and so on, flywheel controller Z is communicatively connected to communication unit Z, and Z = M * N.

[0072] The flywheel energy storage array system is composed of multiple flywheel units, and the communication topology structure between the flywheel units is undirected and connected, thus providing a basis for distributed cooperative control.

[0073] The flywheel energy storage array system of the present invention adopts the flywheel energy storage array cooperative control method of the present invention, and its structural improvement provides a basis for the implementation of the flywheel energy storage array cooperative control method, realizing a significant improvement in the performance of the flywheel energy storage system.

[0074] To sum up, the flywheel energy storage array cooperative control method and the flywheel energy storage array system of the present invention have the following advantages:

[0075] First, it can improve the maximum charge-discharge power of the array: The flywheel energy storage array cooperative control method of the present invention can coordinate the flywheel SOC (state of charge) when responding to the power command, avoid the power reduction problem caused by too large a difference in SOC (state of charge), and thus improve the overall maximum charge-discharge power of the array.

[0076] II. Adapt to different power commands: During the operation of the flywheel energy storage array system of the present invention, power commands are sorted and distributed according to the average SOC (remaining battery capacity), and can be reasonably distributed to flywheel energy storage arrays with different SOC (remaining battery capacity) according to the magnitude and direction of the power commands, so that the remaining battery capacity of the array is effectively adjusted, further improving the adaptability and stability of the system to different power demands.

[0077] III. Reduce the number of operations and balance the SOC (remaining battery capacity): By reasonably arranging the charge and discharge sequence and power distribution of the flywheel energy storage array, the number of charge and discharge operations of the flywheel array is reduced, and at the same time, the balance of the SOC (remaining battery capacity) between the flywheel energy storage arrays is maintained, extending the service life of the flywheel energy storage array system.

[0078] Although the specific embodiments of the present invention have been described above, those skilled in the art should understand that these are only examples, and the protection scope of the present invention is defined by the appended claims. Without departing from the principle and essence of the present invention, those skilled in the art can make various changes or modifications to these embodiments, but these changes and modifications all fall within the protection scope of the present invention.

Claims

1. A flywheel energy storage array coordinated control method, characterized in that: The control method adopts a hierarchical power allocation strategy to perform power allocation, and the control method comprises the following steps: S1, a state estimator calculates and estimates the state parameters of each flywheel unit in the flywheel energy storage array system in real time; S2, sorting the flywheel energy storage arrays in the flywheel energy storage array system in an upper layer according to the average remaining power in the state parameter, and selecting the flywheel energy storage arrays as the priority power allocation targets for power allocation according to the deviation of the average remaining power from the overall average value of the flywheel energy storage array system; S3, in the flywheel energy storage array as the priority power allocation target, calculating the lower power allocation value according to the maximum power ratio of each flywheel unit, and allocating the power to the corresponding flywheel; S4. Repeat steps S2 to S3 until the power requirement of the flywheel energy storage array system is met.

2. The flywheel energy storage array coordinated control method according to claim 1, characterized in that: The state estimator adopts a fixed time estimator based on a dynamic average consensus algorithm. The fixed time estimator has an upper limit on convergence time that is independent of the initial state. When the state parameters of the flywheel differ greatly, it can converge in a shorter time, thereby reducing the impact of estimation errors on the final control effect.

3. The flywheel energy storage array coordinated control method according to claim 1, characterized in that: The step S2 sorts the average remaining power value of each flywheel energy storage array from large to small, determines the charge and discharge direction according to the frequency modulation power instruction of the flywheel energy storage array system, and allocates power to the flywheel energy storage array according to the sorting result of the average remaining power; The step S3 allocates power to the flywheel units under each flywheel energy storage array according to the maximum output ratio principle according to the array power instruction allocated to the flywheel energy storage array.

4. The flywheel energy storage array coordinated control method according to claim 1, characterized in that: The power distribution of the flywheel energy storage array is based on the charging and discharging direction: When charging, the distribution starts from the flywheel energy storage array with the lowest average remaining power value, and the array power command is compared with the maximum charging power of the flywheel energy storage array. If the array power command is greater than the maximum power, the reference charging power is set equal to the maximum power, and the remaining array power command is updated; if the array power command is less than the maximum power, the reference charging power is set equal to the command, and the remaining array power command is set to 0; When discharging, the flywheel energy storage array with the highest average remaining power value is allocated first, and the array power instruction is compared with the maximum discharge power of the flywheel energy storage array. If the array power instruction is less than or equal to the maximum power, the reference discharge power is set equal to the maximum power, and the remaining array power instruction is updated; if the array power instruction is greater than the maximum power, the reference discharge power is set equal to the instruction, and the remaining array power instruction is set to 0; Until the power command distribution is completed or all flywheels are assigned a non-zero power command.

5. A flywheel energy storage array system, characterized in that: The flywheel energy storage array system is controlled by the flywheel energy storage array coordinated control method according to any one of claims 1 to 4. The flywheel energy storage array system includes a plurality of flywheel energy storage arrays, and each of the flywheel energy storage arrays includes a plurality of flywheel units; Each of the flywheel units includes a flywheel controller; Each of the flywheel energy storage arrays is configured with an array controller, and the array controller is electrically connected or communicatively connected to the flywheel controllers of each of the flywheel units in the flywheel energy storage array; The flywheel energy storage array system is equipped with a group controller, and the group controller is electrically or communicatively connected with each array controller.

6. The flywheel energy storage array system according to claim 5, characterized in that: The flywheel unit also includes a motor, a flywheel and a bidirectional converter.

7. The flywheel energy storage array system according to claim 5, characterized in that: The flywheel energy storage array system is controlled by a fully distributed control algorithm. The flywheel energy storage array system also includes a state estimator and a power estimator. The state estimator is used to calculate and estimate global average state information, and the power estimator is used to calculate and estimate average power.

8. The flywheel energy storage array system according to claim 5, characterized in that: The flywheel controllers mutually transmit the status parameters of the flywheel units, and the status parameters of the flywheel units include: flywheel speed, flywheel unit power, and flywheel torque.

9. The flywheel energy storage array system according to claim 5, characterized in that: The group controller is used to sort the flywheel energy storage arrays in the flywheel energy storage array system according to the average remaining power in the state parameter, and select the flywheel energy storage arrays as the priority power allocation targets for power allocation according to the deviation of the average remaining power from the overall average value of the flywheel energy storage array system; The array controller is used to calculate the lower power distribution value according to the maximum power ratio of each flywheel unit in the flywheel energy storage array as the priority power distribution target, and distribute the power to the corresponding flywheel.

10. The flywheel energy storage array system according to claim 5, characterized in that: The group controller is used to obtain the flywheel array power and flywheel array power information in the array controller, and transmit the array power instruction to the array controller; the array controller is used to obtain the flywheel speed, flywheel unit power and flywheel unit power information in the flywheel controller, and transmit the flywheel power instruction to the flywheel controller.

11. The flywheel energy storage array system according to claim 5, characterized in that: Each flywheel controller is communicatively connected to a communication unit, and the communication units in the flywheel energy storage array system are communicatively connected to each other to form a communication network.

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