Active frequency support control method and system for energy storage group microgrid

Abstract

The invention discloses an active frequency support control method and system for an energy storage group micro-grid, and belongs to the technical field of micro-grid frequency control, and the method comprises the steps: for a first region, measuring a region control error, and calculating a corresponding characterization parameter according to the region control error; if yes, transmitting the sampling data by adopting a time triggering strategy, so that the LFC controller generates a control signal; if yes, data transmission is carried out by adopting an event triggering strategy, so that the LFC controller generates a control signal; after the control signal is generated, the control signal is distributed to the generator and each energy storage system according to the corresponding participation degree to serve as a secondary control signal of the generator and each energy storage system, and active frequency support control over the first area is achieved; the upper limit of the saturation function is 1, and the saturation function is a preset reference value. The optimal balance between the control performance and the control input updating times can be realized, and the frequency stability and efficient operation of the micro-grid are ensured.

Description

Technical Field

[0001] This invention belongs to the field of microgrid frequency control technology, and more specifically, relates to an active frequency support control method and system for energy storage microgrids. Background Technology

[0002] With the continuous increase in renewable energy penetration, microgrid frequency stability faces increasingly severe challenges. Load Frequency Control (LFC) is a core means of maintaining system frequency stability, ensuring power quality, and controlling power exchange between controlled areas (i.e., tie-line power). Integrating energy storage systems into LFC to provide additional regulation capabilities has become an effective way to enhance microgrid frequency stability. However, current methods employ a constant-frequency regulation power allocation scheme for generators and energy storage groups, which limits the flexibility and performance optimization potential of energy storage groups in coordinated control and increases the risk of overcharging or over-discharging.

[0003] Traditional LFC (Low-Frequency Control) methods are typically based on periodic sampling and communication, meaning that the controller exchanges data with each measurement point and actuator at fixed intervals regardless of the system state. While this time-triggered mechanism is simple and reliable, it generates a large amount of redundant communication and control actions when the system is in a steady state or experiencing minor disturbances. To reduce unnecessary communication, event-triggered control mechanisms have been introduced into the LFC field. The basic idea is that data transmission and control updates are only performed when the system state meets preset trigger conditions. Existing event-triggered LFC mechanisms mostly use fixed threshold trigger conditions, and these preset thresholds are fixed and cannot be adaptively adjusted, making it difficult to adaptively cope with the complex changes in the system from large disturbances to small disturbances or steady state. Therefore, adaptive event-triggered mechanisms have emerged, which can adaptively adjust threshold parameters according to the system state. However, current adaptive event-triggered LFC mechanisms only focus on the amplitude of signal fluctuations, ignoring the magnitude of the signal itself, and cannot comprehensively reflect the dynamic characteristics and urgency of the system.

[0004] Therefore, it is urgent to design a power allocation strategy that can adaptively adjust the participation of energy storage groups, and to establish an intelligent event triggering mechanism that can sense the severity of regional control errors and dynamically adjust the triggering strategy. This will improve the flexibility of frequency regulation and achieve the best balance between control performance and the number of control input updates, which is of great significance for ensuring the stable and efficient operation of microgrids. Summary of the Invention

[0005] To address the shortcomings and improvement needs of existing technologies, this invention provides an active frequency support control method and system for energy storage microgrids. Its purpose is to achieve the optimal balance between control performance and the number of control input updates, thereby ensuring the frequency stability and efficient operation of the microgrid.

[0006] To achieve the above objectives, according to one aspect of the present invention, an active frequency support control method for energy storage microgrids is provided, comprising: Active frequency support control is performed on each region of the microgrid, and for the first... The active frequency support control implemented in each region includes: Measurement area control error and in accordance with Calculate the corresponding characterization parameters ; like A time-triggered strategy is used to transmit sampled data so that the LFC controller can generate control signals; if Then, an event-triggered strategy is used for data transmission, thereby enabling the LFC controller to generate control signals; After the control signal is generated, it is distributed to the generator and each energy storage system in the energy storage group according to the corresponding participation degree, serving as a secondary control signal for the generator and each energy storage system to achieve control over the first energy storage system. Active frequency support control for each region; in, , This represents the total number of areas in a microgrid; Indicates the frequency deviation factor; A saturation function with an upper limit of 1. Indicates area control error The absolute value, This is a preset reference value.

[0007] Furthermore, the participation of generators The calculation expression is:

[0008] The first in the energy storage group Participation of individual energy storage systems The calculation method is as follows: like ,but ( ) like ,but ( ) in, Indicates time, , respectively representing the indices of flywheel energy storage systems, battery energy storage systems, and electric vehicles in the energy storage group; , ; , ; Indicates the first State of Charge (SoC) value of an energy storage system; It is the rated capacity of the generator. Indicates the first The rated capacity of an energy storage system It is the total capacity of all energy storage systems. It is the total capacity of generators and energy storage systems.

[0009] Furthermore, the dynamic relationships between various physical quantities during the frequency regulation process of the microgrid are described using an event-triggered LFC closed-loop system model; the expression of the event-triggered LFC closed-loop system model is as follows:

[0010] in, Indicates the system status. For the mechanical power output of the generator, For changes in valve opening, This refers to the output power of the flywheel energy storage system. The output power of the battery energy storage system. For the output power of electric vehicles, Output power of renewable energy ; Represents the system state matrix; , , , Indicates system output, It is a series of integers. , Indicates the current sampling time. Indicates the previous trigger time. Indicates the next trigger time. Indicates the sampling period; ; Represents the input matrix, Indicates the controller gain; Indicates system disturbance; , The inertia coefficient, The time constant for renewable energy; Represents the system output matrix; , , , This indicates the measurement delay at the previous trigger time. .

[0011] Furthermore, the system state matrix Its off-diagonal elements and diagonal elements The expression is:

[0012] in, The damping coefficient is... For the region and The synchronization torque coefficient between them The inertial time constant of the prime mover The inertial time constant of the speed controller. This is the velocity droop coefficient. For the first The droop coefficient of an energy storage system The time constant of the flywheel energy storage system The time constant of the battery energy storage system. The gain coefficient of the flywheel energy storage system. This represents the gain coefficient of the battery energy storage system. The time constant of the flywheel energy storage system The time constant of the battery energy storage system. The time constant of the electric vehicle, This represents the gain coefficient for electric vehicles.

[0013] Furthermore, the input matrix ,and The expression is:

[0014] in, This represents a diagonal matrix.

[0015] Furthermore, when using an event-triggered strategy, the triggering condition is:

[0016] in, It is a threshold parameter. , It is a positive definite event triggering weight matrix.

[0017] Furthermore, the threshold parameter The methods for determining the maximum value include: S1: Initialize the system state matrix Input matrix Output matrix and matrix Set the sampling period Time Delay Adjustable parameters and Performance indicators ; S2: Set the search range The lower bound of the threshold parameter And the upper realm At the same time, set the precision coefficient to ; S3: Calculate when At that time, check whether the preset Lyapunov stability criterion is satisfied; if so, update... Otherwise, update ; The Lyapunov stability criterion is: For a given sampling period Time Delay Threshold parameter and adjustable parameters and If a matrix exists , , , , , , , , , and ,for , If the following inequality holds, then the stability condition is satisfied.

[0018]

[0019] in, , ; , ; The transpose of the matrix pairs; , , , , , , , , , , , , , , , , , , , , , , It is the identity matrix. Represents the system state matrix The number of columns, Representation matrix The number of columns; S4: During the repeated execution of S3, if the following conditions are met... Then record the maximum value of the threshold parameter. Then it transitioned to S5; S5: If Output Otherwise, return to S1 and reset the parameters.

[0020] Furthermore, controller gain The calculation expression is:

[0021] in, This is a preset matrix.

[0022] Furthermore, the positive definite pre-defined matrix The calculation expression is:

[0023] in, .

[0024] According to another aspect of the present invention, an active frequency support control system for a microgrid with energy storage clusters is provided, comprising N active frequency support control modules, each used for active frequency support control of a region within the microgrid; and for controlling the frequency of the Nth region. The active frequency support control module that performs active frequency support control in each region includes: LFC controller, used to generate control signals; Sampling measurement unit, used to measure area control error and in accordance with Calculate the corresponding characterization parameters ; Error sensing unit, used in At that time, a time-triggered strategy is used to transmit sampled data so that the LFC controller can generate control signals. When this happens, an event-triggered strategy is used for data transmission, which in turn causes the LFC controller to generate control signals; The secondary control unit is used to distribute the control signal to the generator and each energy storage system in the energy storage group according to the corresponding participation degree after the control signal is generated, serving as the secondary control signal for the generator and each energy storage system, thereby realizing the control of the second energy storage system. Active frequency support control for each region; in, , This represents the total number of areas in a microgrid; Indicates the frequency deviation factor; A saturation function with an upper limit of 1. Indicates area control error The absolute value, This is a preset reference value.

[0025] In summary, the above-described technical solutions conceived in this invention can achieve the following beneficial effects: (1) This invention implements an error-aware hybrid event triggering mechanism, specifically, in acquiring regional control error Then, further in accordance with Calculate the characterization parameters of the regional control error. It can reflect the magnitude and changes of regional control error signals, thereby providing guidance for adjusting control strategies. This invention characterizes parameters... A time-triggered strategy is employed, which can quickly reduce the area control error to a safe range; when characterizing parameters When an event-triggered strategy is adopted, the number of control input updates can be effectively reduced when the regional control error is not large, achieving the best balance between control performance and the number of control input updates. This is of great significance for ensuring the frequency stability and efficient operation of microgrids.

[0026] (2) This invention takes into account that when the system frequency and tie-line power decrease, the energy storage group needs to release power, which leads to a decrease in its SoC. Conversely, when the frequency and tie-line power increase, the energy storage group absorbs power, leading to an increase in SoC. Based on this process, this invention proposes an adaptive participation adjustment strategy that takes into account the SoC of the energy storage group. Specifically, the participation of each energy storage system in the charging and discharging states is adaptively adjusted according to the capacity and SoC value of each energy storage system. This allows the energy storage system with a higher SoC to provide more power output during the discharging phase and the energy storage system with a lower SoC to absorb more power during the charging phase. This enhances the flexibility of frequency regulation and helps reduce the risk of overcharging and over-discharging of the energy storage group.

[0027] (3) Based on the derived Lyapunov stability criterion, this invention guides the design of the event-triggered LFC mechanism by maximizing the event triggering threshold parameter, thereby determining the maximum value of the threshold parameter and calculating the controller gain K and the positive definite weight matrix in the event triggering condition. This method ensures that the system is asymptotically stable and possesses... Performance indicators Under the premise of achieving an efficient event-triggered LFC mechanism. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of an active frequency support control method for energy storage microgrids provided in an embodiment of the present invention.

[0029] Figure 2 This is a schematic diagram of an error-aware hybrid event triggering mechanism provided in an embodiment of the present invention. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0031] In this invention, the terms "first," "second," etc. (if present) in the invention and the accompanying drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0032] To ensure stable frequency operation of microgrids while achieving the optimal balance between control performance and the number of control input updates, this invention provides an active frequency support control method and system for energy storage microgrids. By integrating adaptive adjustment of energy storage participation and event-triggered control mechanisms, it improves the flexibility of system frequency regulation and achieves the optimal balance between control performance and the number of control input updates.

[0033] To achieve the above concept, the present invention includes the following aspects: (1) Establish a microgrid LFC system model including generator sets and energy storage groups; (2) Design an adaptive participation adjustment strategy considering the SoC of energy storage groups; (3) Design an error-aware hybrid event triggering mechanism; (4) Establish an event-triggered LFC system model; (5) Analyze the stability of the LFC system based on the Lyapunov stability method; (6) Establish the design conditions for the error-aware hybrid event triggering LFC mechanism and give the design algorithm.

[0034] The following provides a detailed explanation of each part.

[0035] (1) Establish a microgrid LFC system model that includes generator sets and energy storage groups. The first phase of a multi-regional microgrid... ( The active frequency support control framework for each region is as follows: Figure 1 As shown. Definition Indicates the system status. , Control signals , System disturbance , in, , It's a frequency deviation. For tie line power, For the mechanical power output of the generator, For changes in valve opening, ( ) represents the output power of the flywheel (battery) energy storage system. For the output power of electric vehicles, For the output power of renewable energy, For regional control error, For frequency deviation factor, For control signals, For load disturbance, For changes in wind speed and / or solar radiation. According to Figure 1 The following LFC system model can be obtained:

[0036] in, , , , System state matrix Input matrix Output matrix , , Represents a diagonal matrix. System state matrix. In the middle, off-diagonal elements ,Right now The element in the 2nd row and 1st column equal All other elements are zero. The diagonal elements of the system state matrix. , , and The calculation expressions are as follows:

[0037]

[0038]

[0039]

[0040] in, The inertia coefficient, The damping coefficient is... For the region and The synchronization torque coefficient between them The inertial time constant of the prime mover The inertial time constant of the speed controller. This is the velocity droop coefficient. For the time constant of renewable energy, ( ) represents the time constant of the flywheel (battery) energy storage system. ( ) represents the gain coefficient of the flywheel (battery) energy storage system. The time constant of the electric vehicle, This represents the gain coefficient of the electric vehicle. For the participating factors of the generator, ( ) is a participating factor in flywheel (battery) energy storage systems. As a factor in the participation of electric vehicles, ( ) represents the droop factor of the flywheel (battery) energy storage system. This represents the sag coefficient of the electric vehicle.

[0041] Considering the time lag between periodic sampling and measurement, for The designed LFC control law is as follows:

[0042] in, , , , To measure time delay, This is the upper bound for measuring time delay. Let represent the sampling period. Substituting equation (2) into system (1), the closed-loop state-space model of the LFC system can be written as:

[0043] in, ; Indicates the proportional gain of the controller. This represents the integral gain of the controller.

[0044] (2) Design an adaptive participation adjustment strategy for the energy storage group SoC.

[0045] When system frequency and tie-line power decrease, the energy storage system needs to release power, which leads to a decrease in its System-on-Chips (SoC); conversely, when frequency and tie-line power increase, the energy storage system absorbs power, leading to an increase in SoC. To enhance the flexibility of frequency regulation, this invention proposes an adaptive participation adjustment strategy that considers the SoC of the energy storage system. The idea is as follows: during the discharge phase, energy storage systems with higher SoC are responsible for providing more power output; during the charging phase, energy storage systems with lower SoC are responsible for absorbing more power. The proposed adaptive participation adjustment strategy can be expressed as: 1) Generator participation: ; 2) Participation of energy storage groups: Case 1 ( (Energy storage and discharge): ( ); Case 2 ( (Energy storage and charging) ( ), in, , , , , . It is the rated capacity of the generator. ( These are the rated capacities of flywheel energy storage systems, battery energy storage systems, and electric vehicles, respectively. It is the total capacity of all energy storage systems. It is the total capacity of the generator and energy storage group; ( These are the State of Charge (SoC) values ​​for flywheel energy storage systems, battery energy storage systems, and electric vehicles, respectively.

[0046] (3) Design an error-aware hybrid event triggering mechanism.

[0047] The following event triggering conditions will be used to determine the next triggering time in the system. :

[0048] in, It is a threshold parameter. It is a positive definite weight matrix. and , , ( ) is a series of integers, i.e. , Indicates the previous trigger time. Indicates the current sampling time The system output at that time Indicates the previous trigger time The output of the system at that time.

[0049] Definition based on area control error Characterization parameters :

[0050] in, A saturation function with an upper limit of 1. for The absolute value of the signal, This is a preset reference value. Characterization parameter. It can reflect the magnitude and changes of the area control error signal, thus providing guidance for adjusting the control strategy. Threshold parameter The adjustment depends on the basis Characterization parameters Specifically, this mechanism employs a hybrid strategy: Case 1 (large) ):when When, it means The system is relatively large, so it adopts a time-triggered strategy, that is... In this scenario, the controller is updated relatively frequently to ensure that... Quickly reduce to a safe range.

[0051] Case 2 (Small or Medium) ):when When, it means When the error is small or medium, the system switches to an error-aware adaptive event-triggered strategy, i.e. Its definition is as follows.

[0052]

[0053] in, These are the lower and upper bounds of the threshold parameter, respectively. For relative to The sensitivity parameters. In this case, the controller only updates them when needed. Figure 2 The framework of the proposed error-aware hybrid event triggering mechanism is presented. Based on the threshold parameter calculation formula shown in Equation (6), it can be seen that as the characterization parameters of the regional control error increase... As the threshold parameter gradually increases, it gradually decreases, thus triggering the control process more frequently and quickly reducing the area control error to a safe range.

[0054] (4) Establish an event-triggered LFC system model.

[0055] use Equation (4) can be rewritten as follows:

[0056] in, , The event-triggered LFC control law can be written as:

[0057] in, Next, we will consider the interval. Divided into the following subsets : ,

[0058] in, , , , , , and

[0059] definition , .function satisfy , Therefore, the control law (8) is rewritten as:

[0060] Based on control law (9), the following event-triggered LFC closed-loop system model can be obtained:

[0061] in, The length is denoted as ,and , .

[0062] (5) Analyze the stability of LFC system based on Lyapunov stability method.

[0063] This section will construct a Lyapunov functional and derive the stability criterion for closed-loop systems, ensuring that: 1) when... 1) When the initial conditions are zero, the system is asymptotically stable; 2) Under zero initial conditions, for non-zero initial conditions... ,exist , making Established.

[0064] Construct the following Lyapunov functional:

[0065]

[0066]

[0067] in, , , , , , , , and , , , , and All of them are matrices with appropriate dimensions.

[0068] right Differentiation yields: , ,in, , , , , , , , , , , It is the identity matrix. ( ) is a matrix ( The number of columns.

[0069] Therefore, we can obtain:

[0070] in, , , , , .

[0071] By applying the integral inequality based on the free weight matrix, the following inequality can be obtained:

[0072] in, , , and Let be a matrix of appropriate dimension. Based on the closed-loop system (10), the following equation holds:

[0073] in, , , , It is a matrix with appropriate dimensions. According to the event triggering condition (7), we can obtain:

[0074] Furthermore, we can obtain:

[0075] in, , , , , .

[0076] like and If it is established, then Furthermore, we can obtain:

[0077] For both sides of (16) from 0 to Integrating at the same time, we can obtain:

[0078] under zero initial conditions From the following, we can obtain: That is, for non-zero ,have .when Sometimes, Therefore, it can be guaranteed that system (10) is asymptotically stable and has performance.

[0079] Based on the above derivation, the following stability criterion can be obtained: For a given sampling period Time Delay Threshold parameter and controller gain If a matrix exists , , , , , , , , and ,for , If the following inequality holds, then system (10) is asymptotically stable and has Performance indicators (Robust performance indicators).

[0080]

[0081] in, , , The transpose of the matrix pairs is represented by the transpose of the matrix pairs. All of the above matrices have appropriate dimensions.

[0082] (6) Establish the design conditions for the error-aware hybrid event-triggered LFC mechanism and provide the design algorithm. definition , , , , , , , , , , , ,in, and It is an adjustable parameter. for The matrix. Left multiplication And right-multiply by its transpose, and Left multiplication And right-multiply by its transpose. Then, define... The following design conditions for triggering the LFC mechanism can be obtained: For a given sampling period Time Delay Threshold parameter and adjustable parameters and If a matrix exists , , , , , , , , , and ,for , If the following inequality holds, then system (10) is asymptotically stable and has Performance indicators .

[0083]

[0084] in, , , , , ( ) is through the stability criterion Add superscripts to all matrix variables Therefore, the controller gain is obtained. It can be obtained using the following equation:

[0085] The event triggering weight matrix is ​​then determined by the following formula:

[0086] In microgrids, the goal of event-triggered LFC mechanisms is typically to ensure system stability while minimizing the number of control input updates. To achieve this, the design of an event-triggered LFC mechanism can be guided by maximizing the event-triggered threshold parameter, thereby obtaining the desired event-triggered LFC mechanism. Therefore, the following steps are proposed to design an error-aware hybrid event-triggered LFC mechanism with a maximum threshold parameter.

[0087] The threshold parameter is calculated in the following ways: (1) Initialize system parameters: , , , Set sampling period Time Delay Adjustable parameters and Performance indicators ; (2) Set the search range Where the lower bound of the threshold parameter is set And the upper realm At the same time, select a precision coefficient of 1. ; (3) Perform a binary search: In Then, verify the feasibility of conditions (19) and (20). If conditions (19) and (20) are feasible, then update... ,otherwise ; Continue splitting until ,Record , and proceed to step (4); (4) If If the solution is found, proceed to step (5); otherwise, if there is no feasible solution, return to step (1) and reset the parameters. (5) Output the maximum value of the threshold parameter .

[0088] To obtain the maximum value of the threshold parameter At the same time, the matrix can be determined , , Then, the controller gain can be calculated using equations (21) and (22) respectively. positive definite weight matrix .

[0089] Based on the above design, in one embodiment of the present invention, namely Embodiment 1, an active frequency support control method for energy storage microgrids is provided, comprising: Active frequency support control is performed on each region of the microgrid, and for the first... The active frequency support control implemented in each region includes: Measurement area control error and in accordance with Calculate the corresponding characterization parameters ; like A time-triggered strategy is used to transmit sampled data so that the LFC controller can generate control signals; if Then, an event-triggered strategy is used for data transmission, thereby enabling the LFC controller to generate control signals; After the control signal is generated, it is distributed to the generator and each energy storage system in the energy storage group according to the corresponding participation degree, serving as a secondary control signal for the generator and each energy storage system to achieve control over the first energy storage system. Active frequency support control for each region; in, , This represents the total number of areas in a microgrid; Indicates the frequency deviation factor; A saturation function with an upper limit of 1. Indicates area control error The absolute value, This is a preset reference value.

[0090] When the LFC controller generates control signals, it relies on the signals transmitted through the error-aware hybrid event triggering mechanism; when designing an error-aware hybrid event triggering LFC mechanism with a maximum threshold parameter, the threshold parameter... Maximum value, controller gain Positive definite weight matrix All calculations were performed following the design steps outlined above for the maximum threshold parameter. Furthermore, during active frequency support control, the participation level of each energy storage system was flexibly adjusted based on its State of Charge (SoC) value.

[0091] In summary, the adaptive participation adjustment strategy for the energy storage group's SoC designed in this embodiment achieves adaptive adjustment of the energy storage group's participation. The designed error-aware hybrid event triggering mechanism can flexibly switch between error-aware adaptive event triggering strategy and time triggering strategy according to changes in characterization parameters, achieving an optimal balance between control performance and the number of control input updates. The proposed error-aware hybrid event triggering LFC mechanism design algorithm with a maximum threshold parameter guides the scheme design by maximizing the event triggering threshold parameter, resulting in an efficient event triggering LFC mechanism. In conclusion, this embodiment has advantages such as automatic and flexible adjustment, flexible triggering strategy, and efficient mechanism design, making it suitable for microgrid load frequency control and possessing broad application prospects and high practical value.

[0092] In another embodiment of the present invention, namely Embodiment 2, an active frequency support control system for energy storage microgrids is provided, comprising N active frequency support control modules, each used to perform active frequency support control on a different region within the microgrid; and for controlling the frequency of the first... The active frequency support control module that performs active frequency support control in each region includes: LFC controller, used to generate control signals; Sampling measurement unit, used to measure area control error and in accordance with Calculate the corresponding characterization parameters ; Error sensing unit, used in At that time, a time-triggered strategy is used to transmit sampled data so that the LFC controller can generate control signals. When this happens, an event-triggered strategy is used for data transmission, which in turn causes the LFC controller to generate control signals; The secondary control unit is used to distribute the control signal to the generator and each energy storage system in the energy storage group according to the corresponding participation degree after the control signal is generated, serving as the secondary control signal for the generator and each energy storage system, thereby realizing the control of the second energy storage system. Active frequency support control for each region; in, , This represents the total number of areas in a microgrid; Indicates the frequency deviation factor; A saturation function with an upper limit of 1. Indicates area control error The absolute value, This is a preset reference value.

[0093] In this embodiment, the specific implementation methods of each module can be referred to the description in Embodiment 1 above, and will not be repeated here.

[0094] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An active frequency support control method for energy storage microgrids, characterized in that, include: Active frequency support control is performed on each region of the microgrid, and for the first... The active frequency support control implemented in each region includes: Measurement area control error and in accordance with Calculate the corresponding characterization parameters ; like A time-triggered strategy is used to transmit sampled data so that the LFC controller can generate control signals; if Then, an event-triggered strategy is used for data transmission, thereby enabling the LFC controller to generate control signals; After the control signal is generated, it is distributed to the generator and each energy storage system in the energy storage group according to the corresponding participation degree, serving as a secondary control signal for the generator and each energy storage system to achieve control over the first energy storage system. Active frequency support control for each region; in, , This represents the total number of areas in the microgrid; Indicates the frequency deviation factor; A saturation function with an upper limit of 1. Indicates area control error The absolute value, This is a preset reference value.

2. The active frequency support control method for energy storage microgrids as described in claim 1, characterized in that, Generator participation The calculation expression is: The first in the energy storage group Participation of individual energy storage systems The calculation method is as follows: like ,but ( ) like ,but ( ) in, Indicates time, , respectively representing the indices of the flywheel energy storage system, battery energy storage system, and electric vehicle in the energy storage group; , ; , ; Indicates the first State of Charge (SoC) value of an energy storage system; It is the rated capacity of the generator. Indicates the first The rated capacity of an energy storage system It is the total capacity of all energy storage systems. It is the total capacity of generators and energy storage systems.

3. The active frequency support control method for energy storage microgrids as described in claim 2, characterized in that, The dynamic relationships between various physical quantities during the frequency regulation process of the microgrid are described by an event-triggered LFC closed-loop system model; the expression of the event-triggered LFC closed-loop system model is as follows: in, Indicates the system status. For the mechanical power output of the generator, For changes in valve opening, This refers to the output power of the flywheel energy storage system. The output power of the battery energy storage system. For the output power of electric vehicles, Output power of renewable energy ; Represents the system state matrix; , , , Indicates system output, It is a series of integers. , Indicates the current sampling time. Indicates the previous trigger time. Indicates the next trigger time. Indicates the sampling period; ; Represents the input matrix, Indicates the controller gain; Indicates system disturbance; , The inertia coefficient, The time constant for renewable energy; Represents the system output matrix; , , , This indicates the measurement delay at the previous trigger time. .

4. The active frequency support control method for energy storage microgrids as described in claim 3, characterized in that, System state matrix Its off-diagonal elements and diagonal elements The expression is: in, The damping coefficient is... For the region and The synchronization torque coefficient between them The inertial time constant of the prime mover The inertial time constant of the speed controller. This is the velocity droop coefficient. For the first The droop coefficient of an energy storage system The time constant of the flywheel energy storage system The time constant of the battery energy storage system. The gain coefficient of the flywheel energy storage system. This represents the gain coefficient of the battery energy storage system. The time constant of the flywheel energy storage system The time constant of the battery energy storage system. The time constant of the electric vehicle, This represents the gain coefficient for electric vehicles.

5. The active frequency support control method for energy storage microgrids as described in claim 4, characterized in that, Input matrix ,and The expression is: in, This represents a diagonal matrix.

6. The active frequency support control method for energy storage microgrids as described in claim 5, characterized in that, When using an event-triggered strategy, the triggering condition is: in, It is a threshold parameter. , It is a positive definite event triggering weight matrix.

7. The active frequency support control method for energy storage microgrids as described in claim 6, characterized in that, Threshold parameter The methods for determining the maximum value include: S1: Initialize the system state matrix Input matrix Output matrix and matrix Set the sampling period Time Delay Adjustable parameters and Performance indicators ; S2: Set the search range The lower bound of the threshold parameter And the upper realm At the same time, set the precision coefficient to ; S3: Calculate when At that time, check whether the preset Lyapunov stability criterion is satisfied; if so, update... Otherwise, update ; The Lyapunov stability criterion is as follows: For a given sampling period Time Delay Threshold parameter and adjustable parameters and If a matrix exists , , , , , , , , , and ,for , If the following inequality holds, then the stability condition is satisfied. in, , ; , ; The transpose of the matrix pairs; , , , , , , , , , , , , , , , , , , , , , , It is the identity matrix. Represents the system state matrix The number of columns, Representation matrix The number of columns; S4: During the repeated execution of S3, if the following conditions are met... Then record the maximum value of the threshold parameter. Then it transitioned to S5; S5: If Output Otherwise, return to S1 and reset the parameters.

8. The active frequency support control method for energy storage microgrids as described in claim 7, characterized in that, Controller gain The calculation expression is: in, This is a preset matrix.

9. The active frequency support control method for energy storage microgrids as described in claim 8, characterized in that, Positive definite event triggering weight matrix The calculation expression is: in, .

10. An active frequency support control system for energy storage microgrids, characterized in that, It includes N active frequency support control modules, each used to perform active frequency support control on each region of the microgrid; and for controlling the frequency of the first... The active frequency support control module that performs active frequency support control in each region includes: LFC controller, used to generate control signals; Sampling measurement unit, used to measure area control error and in accordance with Calculate the corresponding characterization parameters ; Error sensing unit, used in At that time, a time-triggered strategy is used to transmit sampled data so that the LFC controller can generate control signals. When this happens, an event-triggered strategy is used for data transmission, which in turn causes the LFC controller to generate control signals; The secondary control unit is used to distribute the control signal to the generator and each energy storage system in the energy storage group according to the corresponding participation degree after the control signal is generated, serving as the secondary control signal for the generator and each energy storage system, thereby realizing the control of the second energy storage system. Active frequency support control for each region; in, , This represents the total number of areas in the microgrid; Indicates the frequency deviation factor; A saturation function with an upper limit of 1. Indicates area control error The absolute value, This is a preset reference value.

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