A microgrid on-grid and off-grid smooth switching control system and device

Abstract

The present application relates to the technical field of on-grid and off-grid switching, and specifically to a control system and device for smooth on-grid and off-grid switching of a microgrid. The system includes: a power grid data acquisition module, which obtains the data of monitoring parameters of each monitoring point of the microgrid line at each acquisition moment; a microgrid state analysis module, including a power grid trend fluctuation analysis submodule and a power grid response imbalance analysis submodule; analyzes the correlation between the monitoring parameters of the monitoring points at each common connection point and the distribution power supply monitoring point, and extracts each imbalance response set; calculates the asynchronous coefficient between any two monitoring points in the imbalance response set, and obtains the dynamic imbalance response difference of each monitoring point in combination with the lag time difference between each monitoring point and each other monitoring point; a microgrid on-grid and off-grid switching control module, which obtains the on-grid and off-grid switching control coefficient of the microgrid through the dynamic imbalance response difference, and performs on-grid and off-grid switching control of the microgrid. The present application can effectively control the on-grid and off-grid switching of the microgrid.

Description

Technical Field

[0001] The present application relates to the technical field of on-grid and off-grid switching, and in particular to a control system and device for smooth on-grid and off-grid switching of a microgrid. Background Art

[0002] The on-grid and off-grid switching of microgrids is of great significance. In the on-grid state, the microgrid is connected to the main grid through a common connection point, and can perform two-way power exchange. The main grid provides it with a stable voltage and frequency reference to improve reliability. When the main grid fails, is planned to be off-grid, or there is a situation that may affect the safety of the main grid, the microgrid switches to the off-grid state and operates independently. The switching process includes a preparation phase, monitoring the status of the main grid and microgrid and adjusting the equipment; during the switching operation, the main grid is disconnected or connected according to the strategy, and the operating status of the equipment is adjusted; after the switching, the off-grid state needs to be closely monitored to ensure stable power supply, and the on-grid state gradually restores power exchange with the main grid. On-grid and off-grid switching realizes the efficient utilization of distributed energy, improves the reliability and flexibility of power supply, and adapts to different operating needs and scenarios.

[0003] However, in the actual application scenarios of microgrids, the operating state of the microgrid will change accordingly due to various interference factors in the application environment and load changes. This change may cause the power to lose balance and further cause voltage and power fluctuations. In addition, in the process of monitoring the operating state of the microgrid, different nodes respond differently to changes in the operating state of the microgrid. This situation causes the existing microgrid operating state monitoring method to produce large errors when analyzing the monitoring parameters, and this error will have an adverse effect on the accuracy of the on-grid and off-grid switching control based on the operating state of the microgrid. Summary of the invention

[0004] In order to solve the above technical problems, the purpose of this application is to provide a microgrid on-grid and off-grid smooth switching control system and device, and the technical solutions adopted are as follows:

[0005] The present application proposes a microgrid on-grid and off-grid smooth switching control system and device, the system comprising:

[0006] The power grid data acquisition module sets monitoring points at each public connection point and distribution power supply of the microgrid line to obtain the data of monitoring parameters at each monitoring point at each acquisition time. The monitoring parameters include voltage, current, power and frequency;

[0007] A microgrid state analysis module, including a grid trend fluctuation analysis submodule and a grid response imbalance analysis submodule;

[0008] Power grid trend fluctuation analysis submodule: performs correlation analysis on monitoring parameters of monitoring points at each common connection point and distribution power supply monitoring points, obtains maximum correlation coefficient and lag time of monitoring points at each common connection point, and clusters monitoring points at all common connection points based on the maximum correlation coefficient to obtain each imbalance response set;

[0009] According to the correlation between any two monitoring points in the imbalance response set with respect to the same monitoring parameter and the average importance of the any two monitoring points with respect to the same monitoring parameter, obtaining an asynchronous coefficient between the any two monitoring points;

[0010] The power grid response imbalance analysis submodule: according to the lag time difference between each monitoring point in the imbalance response set and each other monitoring point, combined with the asynchronous coefficient between each monitoring point and other monitoring points, obtains the dynamic imbalance response difference of each monitoring point in the imbalance response set;

[0011] The microgrid on-grid and off-grid switching control module obtains the microgrid on-grid and off-grid switching control coefficient through the average level of the dynamic imbalance response difference of the monitoring points in each imbalance response set during the microgrid on-grid and off-grid switching control process, so as to perform smooth on-grid and off-grid switching control of the microgrid.

[0012] Preferably, the process of obtaining the maximum correlation coefficient and lag time of the monitoring points at each common connection point is specifically as follows:

[0013] The cumulative sum of the voltage value, current value, power value and frequency value of the monitoring point at each collection time is recorded as the monitoring coefficient of the monitoring point at each collection time. The monitoring coefficient of the monitoring point at all collection times constitutes the monitoring coefficient sequence of the monitoring point;

[0014] The monitoring coefficient sequences of the monitoring points at each common connection point and the distribution power supply monitoring points are used as the input of the cross-correlation algorithm, and the maximum correlation coefficient and lag time between the monitoring points at each common connection point and the distribution power supply monitoring points are obtained, which are recorded as the maximum correlation coefficient and lag time of the monitoring points at each common connection point, respectively.

[0015] Preferably, each imbalance response set is a set consisting of monitoring points corresponding to all maximum correlation coefficients in each cluster after clustering.

[0016] Preferably, the expression of the asynchronous coefficient between any two monitoring points is: ;in, represents the first Asynchronous coefficient between the first and jth monitoring points; Indicates and Monitoring point about Pearson correlation coefficient between the monitoring data series of the monitoring parameters; Indicates and Monitoring point about The mean of the weights of the monitoring parameters, where the weights of the monitoring parameters are obtained through an objective weighting method; Indicates the number of types of monitoring parameters.

[0017] Preferably, the process of obtaining the weights of the monitoring parameters further includes: taking the monitoring data sequence of each monitoring parameter at each monitoring point in the imbalance response set as input, and using an objective weighting method to obtain the weight of each monitoring parameter at each monitoring point, wherein the monitoring data sequence is composed of the normalized results of the data of the monitoring parameters at all acquisition times.

[0018] Preferably, the expression of the dynamic imbalance response of each monitoring point in the imbalance response set is: ;in, represents the first Differences in dynamic imbalance responses among monitoring points; represents the first and Asynchronous coefficient between monitoring points; Indicates and The difference in lag time between the monitoring points; Indicates the number of monitoring points.

[0019] Preferably, the obtaining of the on-grid and off-grid switching control coefficient of the microgrid further comprises:

[0020] The normalized results of the dynamic imbalance response differences of all monitoring points in each imbalance response set are averaged as the grid-connected and off-grid switching response value of each imbalance response set, and the grid-connected and off-grid switching control coefficient of the microgrid is calculated by combining the grid-connected and off-grid switching response values ​​of all imbalance analysis sets.

[0021] Preferably, the on-grid and off-grid switching control coefficient of the microgrid is an average value of the on-grid and off-grid switching response values ​​of all imbalance analysis sets.

[0022] Preferably, the control of smooth on-grid and off-grid switching of the microgrid further includes: when the on-grid and off-grid switching control coefficient of the microgrid exceeds a preset threshold, switching to an off-grid state, otherwise, maintaining a on-grid state.

[0023] On the other hand, the present application provides a microgrid on-grid and off-grid smooth switching control device, comprising a memory, a processor, and a computer program stored in the memory and running on the processor, wherein the processor implements a module of any of the above-mentioned systems when executing the computer program.

[0024] This application has the following beneficial effects:

[0025] This application takes into account the changes in the connected load during the operation of the microgrid and the differences in the degree of interference with the operation of the equipment during the operation, which causes the cloud state of the microgrid to be disordered before the warning is reached, affecting the operation of the equipment and load connected to the main grid;

[0026] In response to the above problems, the present application divides the monitoring points by combining the stage-by-stage trend change differences and response delay change characteristics of different monitoring points relative to the main grid during the operation of the microgrid, and further analyzes the asynchronous characteristics of the local responses between different monitoring points based on the division results, and obtains the asynchronous coefficient of the fluctuation change of the local grid node during the on-grid and off-grid switching control monitoring of the microgrid. The beneficial effect is that after the overall characteristic division between the monitoring points and the main grid, the monitoring points with similar delayed response changes can be accurately divided, and then the response differences between the monitoring points in the microgrid can be accurately analyzed;

[0027] Based on the asynchronous coefficient, the imbalance fluctuation differences between different public connection points in the microgrid are compared and analyzed to obtain the dynamic imbalance response difference in the on-grid and off-grid switching control process of the microgrid. The on-grid and off-grid switching of the microgrid is effectively judged by the difference value. The beneficial effect is that the imbalance response difference between the divided monitoring points can timely and accurately reflect the impact of the imbalance fluctuation response on the operating state of the microgrid, make accurate judgments on the on-grid and off-grid switching control of the microgrid, and effectively control the on-grid and off-grid switching of the microgrid. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions and advantages in the embodiments of the present application or the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0029] Figure 1 A block diagram of a microgrid on-grid and off-grid smooth switching control system provided in this application;

[0030] Figure 2 A schematic diagram of the connection structure between the main grid and other connected devices in the microgrid provided in this application;

[0031] Figure 3 A block diagram of the microgrid state analysis process submodule provided in this application;

[0032] Figure 4This is a specific implementation block diagram of the microgrid status analysis module provided in this application. DETAILED DESCRIPTION

[0033] In order to further explain the technical means and effects adopted by the present application to achieve the predetermined invention purpose, the following is a detailed description of the specific implementation method, structure, features and effects of a microgrid on-grid and off-grid smooth switching control system and device proposed in the present application in combination with the accompanying drawings and preferred embodiments. In the following description, different "one embodiment" or "another embodiment" does not necessarily refer to the same embodiment. In addition, specific features, structures or characteristics in one or more embodiments may be combined in any suitable form.

[0034] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

[0035] The specific scheme of a microgrid on-grid and off-grid smooth switching control system and device provided by the present application is described in detail below with reference to the accompanying drawings.

[0036] See also Figure 1 , which shows a block diagram of a microgrid on-grid and off-grid smooth switching control system provided by an embodiment of the present application, the system includes: a power grid data acquisition module, a microgrid state analysis module, and a microgrid on-grid and off-grid switching control module.

[0037] Grid data acquisition module: Monitoring points are set at each public connection point and distribution power supply of the microgrid line to obtain data on monitoring parameters at each monitoring point at each collection time. The monitoring parameters include voltage, current, power and frequency.

[0038] In a microgrid, nodes on the main grid include but are not limited to energy storage devices, distributed power sources and load nodes. Under normal circumstances, the operating state of the microgrid is stable, and the voltage, current and power parameter changes of the main grid and the public connection point are consistent. However, when there are differences in the access conditions of the loads in different time periods and the disturbance response changes of related connected equipment, the operating state of the microgrid will change, thereby affecting the switching control of the microgrid on and off the grid.

[0039] Furthermore, in this embodiment, a schematic diagram of the connection structure between the main grid and other connected devices in the microgrid is as follows: Figure 2 As shown, Figure 2In the figure, numbers 1-2 represent the main grid line and the distribution power supply respectively; the black dot represents the common connection point, that is, the common point where the microgrid is connected to the main grid; numbers 3-4 represent the distributed power supply and the energy storage device respectively; numbers 5-r all represent the load connected to the main grid; a and b represent the converter and the controller respectively, which are components used for AC and DC conversion and switch control respectively. It should be noted that in this embodiment, the above is only a schematic diagram of the microgrid connection, which is used to indicate the position of the common connection point connected to the main grid on the microgrid. Monitoring points are further set at the common connection point and the distribution power supply on the microgrid to monitor the changes in the monitoring parameters between the main grid and the connection node. In specific application scenarios, the implementer sets the monitoring point position according to the actual situation.

[0040] Specifically, in this embodiment, voltage sensors, current sensors, power sensors and frequency sensors are arranged at the set monitoring points, and the data of monitoring parameters in one monitoring cycle at each monitoring point are collected respectively. The monitoring parameters include voltage, current, power and frequency, and each type of data collected at each monitoring point is normalized, and all monitoring data of each monitoring parameter in one monitoring cycle are combined into a monitoring data sequence of each monitoring parameter. In this embodiment, the time interval for data collection is 0.1s, and the monitoring cycle is 15min, which can be set by the implementer. The normalization method adopts Z-Score normalization, and the implementer can also select other existing normalization methods.

[0041] At this point, the monitoring parameters of each monitoring point in the on-grid and off-grid switching control process of the microgrid are obtained.

[0042] Microgrid status analysis module: includes grid trend fluctuation analysis submodule and grid response imbalance analysis submodule.

[0043] Normally, the on-grid and off-grid switching control of a microgrid is mainly related to the operating state of the microgrid. If the operating state of the microgrid is disturbed and there is a large difference in the response changes of the node devices and loads connected to the microgrid, the microgrid needs to be switched from the on-grid state to the off-grid state. However, in the monitoring process of the state of the microgrid, the difference in the response state changes between the nodes connected to the main grid due to load changes is not fully considered, which affects the judgment of the operating state of the microgrid. That is, when the monitoring parameters of the main grid are within the set stable changes, the judgment of the operating state of the microgrid will have a large error, which affects the accuracy of the on-grid and off-grid switching control of the microgrid.

[0044] Specifically, the block diagram of the microgrid state analysis process submodule is as follows: Figure 3 shown.

[0045] The process of microgrid on-grid and off-grid status analysis specifically includes:

[0046] Power grid trend fluctuation analysis submodule: perform correlation analysis on the monitoring parameters of the monitoring points at each common connection point and the distribution power supply monitoring point, obtain the maximum correlation coefficient and lag time of the monitoring points at each common connection point, cluster the monitoring points at all common connection points based on the maximum correlation coefficient to obtain each imbalance response set; obtain the asynchronous coefficient between any two monitoring points based on the correlation between the same monitoring parameters of any two monitoring points in the imbalance response set and the average importance of the same monitoring parameters of the any two monitoring points.

[0047] In this embodiment, it is considered that the operating state of the main grid and the operating state of the connected nodes in the main grid have response differences during the operation of the microgrid, which may cause an imbalance, thereby affecting the stability of the power supply of the main grid to the connected nodes; therefore, the response characteristics of the microgrid operating state are analyzed according to the asynchronous change difference between the collected monitoring parameters of the main grid and the response changes between the common connection points on the main grid. The specific calculation and analysis process is as follows:

[0048] Due to the influence of transmission distance during the operation of the microgrid, there are trend change differences and response delay differences between the main grid and the public connection point in different time periods; therefore, for each monitoring point in the on-grid and off-grid switching control process of the microgrid, the cumulative sum of the voltage value, current value, power value and frequency value of the monitoring point at the same collection time is used as the monitoring coefficient of the monitoring point at the corresponding collection time, and the monitoring coefficient of the monitoring point at all collection times constitutes the monitoring coefficient sequence of the monitoring point; the monitoring coefficient at each collection time reflects the comprehensive change characteristics of the operating data of the monitoring point in a monitoring cycle during the operation of the microgrid;

[0049] In this embodiment, the monitoring coefficient sequence of the monitoring point at each common connection point and the distribution power supply monitoring point is used as the input of the cross-correlation algorithm, and the maximum correlation coefficient and lag time between the monitoring point at each common connection point and the distribution power supply monitoring point are respectively obtained by the cross-correlation algorithm, which are recorded as the maximum correlation coefficient and lag time of the monitoring point at each common connection point; the specific calculation process of the cross-correlation algorithm is a well-known technology and will not be repeated here;

[0050] In order to further conduct a comprehensive comparative analysis of the response lag characteristics between the grid operation parameters at different public connection points on the main grid within a monitoring cycle, the maximum correlation coefficient of the monitoring points at all public connection points is taken as input, and the agglomerative hierarchical clustering algorithm is used to obtain the clustering results of all maximum correlation coefficients. In this embodiment, the metric distance in the clustering process is the Euclidean distance of different maximum correlation coefficients.

[0051] Furthermore, the set consisting of all monitoring points corresponding to the maximum correlation coefficients in each cluster in the above clustering results is taken as each imbalance response set, and then the parameter change characteristics of the imbalance response in the microgrid's on-grid and off-grid switching control process are analyzed according to the division results of the monitoring points at each public connection point.

[0052] In order to accurately analyze the correlation response of the grid operation parameters at different monitoring points during the operation of the microgrid, and then effectively judge the switching response characteristics of the on-grid and off-grid; for the unbalanced response set of each microgrid operation process parameter change obtained during the on-grid and off-grid switching control monitoring of the microgrid, calculate the Pearson correlation coefficient between the same monitoring parameters corresponding to any two monitoring points in the unbalanced response set. The larger the Pearson correlation coefficient, the more significant the correlation response of the parameter changes of the grid operation state measured between the monitoring points of the microgrid after the difference in the overall grid parameter response changes of different monitoring points relative to the main grid is divided;

[0053] Furthermore, the relative response changes of microgrid parameters between monitoring points during the switching control monitoring process caused by the change in the operating state of the microgrid during operation are analyzed; specifically, the monitoring data sequence of each monitoring parameter of each monitoring point in the imbalance response set is used as input, and the weight corresponding to each monitoring parameter of each monitoring point is obtained by an objective weighting method; the larger the weight, the more significant the response change of the monitoring parameter corresponding to the monitoring point; the mean value of the weights of the same monitoring parameters corresponding to any two monitoring points is calculated The larger the mean value is, the more significant the response change characteristics between the monitoring points of the microgrid are after the overall response change difference of different monitoring points relative to the main grid is divided;

[0054] According to the analysis results of the correlation response characteristics of different monitoring parameters between each monitoring point and other monitoring points in the imbalance response set, the asynchronous coefficient of the fluctuation change of the local grid node in the process of the microgrid on-grid and off-grid switching control monitoring is calculated. The specific calculation relationship is:

[0055] ;in, represents the first Asynchronous coefficient between the first and jth monitoring points; Indicates and Monitoring point about Pearson correlation coefficient between the monitoring data series of the monitoring parameters; Indicates and Monitoring point about The mean of the weights of the monitoring parameters; Indicates the number of types of monitoring parameters; the larger the calculated asynchronous coefficient, the greater the difference in the operating state response during the on-grid and off-grid switching control monitoring of the microgrid, and the greater the possibility of the microgrid operating state changing.

[0056] Grid response imbalance analysis submodule: According to the lag time difference between each monitoring point and each other monitoring point in the imbalance response set, combined with the asynchronous coefficient between each monitoring point and other monitoring points, the dynamic imbalance response difference of each monitoring point in the imbalance response set is obtained.

[0057] Through the above calculation, the asynchronous response characteristics of the local power grid fluctuation changes between different monitoring points in the unbalanced response set can be obtained. Furthermore, combined with the response delay characteristics of different monitoring points in the unbalanced response set relative to the main power grid, the unbalanced fluctuation differences of different monitoring points in the unbalanced response set are compared and analyzed;

[0058] Specifically, for each monitoring point in the imbalance response set, the difference between the lag time corresponding to the monitoring point and each other monitoring point is calculated. The larger the difference is, the greater the difference in imbalance fluctuation response between the monitoring point and other monitoring points may be.

[0059] According to the difference in lag time between different monitoring points in the imbalance response set and the asynchronous coefficient, the dynamic imbalance response difference in the on-grid and off-grid switching control monitoring process of the microgrid is calculated. , the specific calculation relationship is as follows:

[0060] ;in, represents the first Differences in dynamic imbalance responses among monitoring points; represents the first and Asynchronous coefficient between monitoring points; Indicates and The lag time difference of two monitoring points. In this embodiment, the absolute value of the lag time difference between two monitoring points in the imbalance response set is used to represent the lag time difference between the two monitoring points. Represents the number of monitoring points; the greater the difference in the calculated dynamic imbalance response, the more significant the imbalance fluctuation response of the microgrid at different monitoring points, and the greater the possibility of a change in the operating state of the microgrid.

[0061] At this point, the dynamic imbalance response differences of different monitoring points in the microgrid are obtained.

[0062] Specifically, the specific implementation block diagram of the microgrid state analysis module is as follows: Figure 4 shown.

[0063] Microgrid on-grid and off-grid switching control module: The on-grid and off-grid switching control coefficient of the microgrid is obtained through the average level of the dynamic imbalance response difference of the monitoring points in each imbalance response set during the on-grid and off-grid switching control of the microgrid, so as to perform smooth on-grid and off-grid switching control of the microgrid.

[0064] After the analysis of the above process, the monitoring points on the main grid are divided according to the response lag characteristics of different monitoring points relative to the main grid of the microgrid during the operation of the microgrid, and based on the division results, the asynchronous characteristics of the local responses and the imbalance response fluctuation differences between different monitoring points are compared and analyzed to obtain the dynamic imbalance response differences of different monitoring points in the microgrid, which accurately reflects the degree to which the imbalance fluctuations affect the operating status of the microgrid at different monitoring points during the operation of the microgrid.

[0065] Furthermore, in order to accurately analyze the impact of the unbalanced fluctuation response characteristics on the operating state of the microgrid and accurately control the switching control signal of the microgrid on and off the grid, in this embodiment, for the unbalanced response set obtained during the on-grid and off-grid switching control monitoring process of the microgrid, the dynamic unbalanced response difference of all monitoring points in the unbalanced response set is used as input, and the Z-score normalization algorithm is used to obtain the normalized results of all dynamic unbalanced response differences, and the mean of all elements in the normalized result is used as the on-grid and off-grid switching response value corresponding to each unbalanced response set. .

[0066] Furthermore, in order to further determine the influence of the imbalance fluctuation characteristics of microgrid state monitoring on the control of microgrid on-grid and off-grid switching during the on-grid and off-grid switching control of the microgrid, the mean of the on-grid and off-grid switching response values ​​corresponding to all imbalance analysis sets is used as the on-grid and off-grid switching control coefficient of the microgrid. The larger the on-grid and off-grid switching control coefficient of the microgrid, the greater the possibility that the operating state of the microgrid will be affected by the imbalance response fluctuation and the state will change. In order to ensure stable power supply, the microgrid needs to be switched from the on-grid state to the off-grid state in time; the judgment threshold of the on-grid and off-grid switching is set to If the on-grid and off-grid switching control coefficient exceeds the threshold, it will be switched to the off-grid state in time to detect the change of the operating state of the microgrid in time to avoid the impact of microgrid operation interruption on equipment operation; otherwise, it will maintain the on-grid state.

[0067] On the other hand, this embodiment provides a microgrid on-grid and off-grid smooth switching control device, including a memory, a processor, and a computer program stored in the memory and running on the processor, and the processor implements a module of any of the above-mentioned systems when executing the computer program.

[0068] It should be noted that the sequence of the above embodiments of the present application is only for description and does not represent the advantages and disadvantages of the embodiments. The processes depicted in the accompanying drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0069] The various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referenced to each other, and each embodiment focuses on the differences from other embodiments.

[0070] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions, improvements, etc. made within the principles of the present application should be included in the protection scope of the present application.

Claims

1. A microgrid on-grid and off-grid smooth switching control system, characterized in that: The system comprises: The power grid data acquisition module sets monitoring points at each public connection point and distribution power supply of the microgrid line to obtain the data of monitoring parameters at each monitoring point at each acquisition time. The monitoring parameters include voltage, current, power and frequency; A microgrid state analysis module, including a grid trend fluctuation analysis submodule and a grid response imbalance analysis submodule; Power grid trend fluctuation analysis submodule: performs correlation analysis on monitoring parameters of monitoring points at each common connection point and distribution power supply monitoring points, obtains maximum correlation coefficient and lag time of monitoring points at each common connection point, and clusters monitoring points at all common connection points based on the maximum correlation coefficient to obtain each imbalance response set; According to the correlation between any two monitoring points in the imbalance response set with respect to the same monitoring parameter and the average importance of the any two monitoring points with respect to the same monitoring parameter, obtaining an asynchronous coefficient between the any two monitoring points; The power grid response imbalance analysis submodule: according to the lag time difference between each monitoring point in the imbalance response set and each other monitoring point, combined with the asynchronous coefficient between each monitoring point and other monitoring points, obtains the dynamic imbalance response difference of each monitoring point in the imbalance response set; The microgrid on-grid and off-grid switching control module obtains the microgrid on-grid and off-grid switching control coefficient through the average level of the dynamic imbalance response difference of the monitoring points in each imbalance response set during the microgrid on-grid and off-grid switching control process, so as to perform smooth on-grid and off-grid switching control of the microgrid; The expression of the asynchronous coefficient between any two monitoring points is: ;in, represents the first Asynchronous coefficient between the first and jth monitoring points; Indicates and Monitoring point about Pearson correlation coefficient between the monitoring data series of the monitoring parameters; Indicates and Monitoring point about The mean of the weights of the monitoring parameters, where the weights of the monitoring parameters are obtained through an objective weighting method; Indicates the number of types of monitoring parameters; The expression of the dynamic imbalance response of each monitoring point in the imbalance response set is: ;in, represents the first Differences in dynamic imbalance responses among monitoring points; represents the first and Asynchronous coefficient between monitoring points; Indicates and The difference in lag time between the monitoring points; Indicates the number of monitoring points.

2. A microgrid on-grid and off-grid smooth switching control system as claimed in claim 1, characterized in that: The specific process of obtaining the maximum correlation coefficient and lag time of the monitoring points at each common connection point is as follows: The cumulative sum of the voltage value, current value, power value and frequency value of the monitoring point at each collection time is recorded as the monitoring coefficient of the monitoring point at each collection time. The monitoring coefficient of the monitoring point at all collection times constitutes the monitoring coefficient sequence of the monitoring point; The monitoring coefficient sequences of the monitoring points at each common connection point and the distribution power supply monitoring points are used as the input of the cross-correlation algorithm, and the maximum correlation coefficient and lag time between the monitoring points at each common connection point and the distribution power supply monitoring points are obtained, which are recorded as the maximum correlation coefficient and lag time of the monitoring points at each common connection point, respectively.

3. A microgrid on-grid and off-grid smooth switching control system as claimed in claim 1, characterized in that: Each imbalance response set is a set consisting of monitoring points corresponding to all maximum correlation coefficients in each cluster after clustering.

4. A microgrid on-grid and off-grid smooth switching control system as claimed in claim 1, characterized in that: The process of obtaining the weight of the monitoring parameter further includes: taking the monitoring data sequence of each monitoring parameter at each monitoring point in the imbalance response set as input, and using an objective weighting method to obtain the weight of each monitoring parameter at each monitoring point, wherein the monitoring data sequence is composed of the normalized results of the data of the monitoring parameter at all acquisition times.

5. A microgrid on-grid and off-grid smooth switching control system as claimed in claim 1, characterized in that: The obtaining of the microgrid on-grid and off-grid switching control coefficient further comprises: The normalized results of the dynamic imbalance response differences of all monitoring points in each imbalance response set are averaged as the grid-connected and off-grid switching response value of each imbalance response set, and the grid-connected and off-grid switching control coefficient of the microgrid is calculated by combining the grid-connected and off-grid switching response values ​​of all imbalance analysis sets.

6. A microgrid on-grid and off-grid smooth switching control system as claimed in claim 5, characterized in that: The on-grid and off-grid switching control coefficient of the microgrid is an average value of the on-grid and off-grid switching response values ​​of all imbalance analysis sets.

7. A microgrid on-grid and off-grid smooth switching control system as claimed in claim 1, characterized in that: The control of smooth on-grid and off-grid switching of the microgrid further includes: when the on-grid and off-grid switching control coefficient of the microgrid exceeds a preset threshold, switching to an off-grid state, otherwise, maintaining a on-grid state.

8. A microgrid on-grid and off-grid smooth switching control device, comprising a memory, a processor, and a computer program stored in the memory and running on the processor, characterized in that: When the processor executes the computer program, the module of the system according to any one of claims 1 to 7 is implemented.

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