Micro-grid virtual synchronous continuous switching control method and system

Abstract

The application relates to the technical field of micro-grid control, and discloses a micro-grid virtual synchronous continuous switching control method and system, which comprises the following steps: constructing an action time delay feature library according to target circuit breaker historical action data in industrial big data; in response to a micro-grid switching instruction, determining a target action time according to a current working condition; determining a virtual synchronous machine target synchronous state according to the target action time and a power grid side voltage; forming a predicted action time period by using an action time delay range, and controlling the virtual synchronous machine to continuously adjust and then send an action command; after the action command is sent, screening historical action data according to an operating coil actual action stage, determining a residual action time range, and updating the synchronous state; and confirming actual conduction or actual separation according to a branch electrical state. For a low exchange power closing state, actual conduction is confirmed through virtual internal potential test change and branch current response. The application can improve the time corresponding degree of the circuit breaker mechanical action process and the virtual synchronous switching process.

Description

Technical Field

[0001] This invention relates to the field of microgrid operation control technology, and in particular to a virtual synchronous continuous switching control method and system for microgrids. Background Technology

[0002] Microgrids typically operate in both grid-connected and off-grid states. In grid-connected mode, the microgrid is connected to the upper-level grid via a point of common coupling. In off-grid mode, a power source with grid-connection capabilities is required to establish the voltage and frequency references within the microgrid. Virtual synchronous machines, by simulating the inertia, damping, and excitation regulation characteristics of synchronous generators, can be used for grid-connected and off-grid operation control of energy storage converters and other grid-connected converters.

[0003] In related technologies, when a microgrid switches from off-grid to grid-connected status, the phase difference, frequency difference, and voltage amplitude difference between the microgrid-side voltage and the grid-side voltage are typically detected. After the electrical quantities meet the preset synchronization conditions, a closing command is sent to the circuit breaker at the point of common coupling. When the microgrid switches from grid-connected to off-grid status, the circuit breaker is controlled to open after an off-grid command is generated, and the virtual synchronizing machine assumes the voltage and frequency support within the microgrid.

[0004] However, after receiving an action command, the circuit breaker needs to go through processes such as operating circuit response, operating coil current establishment, operating mechanism movement, and main contact movement. There is a time interval between the moment of the action command and the moment the electrical state switching is actually completed, and this time interval can change with the operating power supply status, environmental status, equipment usage status, and maintenance status. Industrial big data generated during long-term operation in industrial sites can record the historical action processes of circuit breakers and their corresponding operating conditions, but related technologies typically do not correlate the individual action characteristics of circuit breakers in this industrial big data with the continuous switching process of a virtual synchronous machine. Determining the synchronization state based on the moment the action command is issued may lead to a new phase difference between the microgrid side and the grid side when the main contacts actually conduct; determining the synchronization state based on a single predicted action time may also reduce the correspondence between the synchronization control result and the actual action time of the main contacts when the actual action process of the circuit breaker deviates from the historical prediction.

[0005] Furthermore, when the grid-connected power of the microgrid is close to zero, even if the target circuit breaker has not actually been turned on, the pre-synchronization control may keep the voltages on both sides of the circuit breaker in a similar state for a long time. Therefore, it is difficult to reliably determine whether the main circuit has been established by relying solely on the similarity of the phase and frequency on both sides of the circuit breaker.

[0006] Therefore, how to determine and update the time range within which the circuit breaker may complete the actual electrical state switching based on the current operating condition of the target circuit breaker and the actual mechanical action process currently taking place, and how to ensure that the virtual synchronous machine maintains a suitable synchronous state within this time range, is a technical problem that needs to be solved. Summary of the Invention

[0007] The main purpose of this application is to provide a virtual synchronous continuous switching control method and system for microgrids, which aims to solve the problem that the switching time used in virtual synchronous control does not correspond to the actual electrical state switching process of the circuit breaker.

[0008] To achieve the above objectives, the present invention provides a microgrid virtual synchronous continuous switching control method, the method comprising the following steps: Acquire industrial big data containing historical action data of the target circuit breaker and construct an action delay feature library; In response to a microgrid switching command, the current operating condition data of the target circuit breaker is obtained, and the target action time is determined based on the current operating condition data and the action delay feature library. Acquire target grid-side voltage data, and determine the target synchronization state of the virtual synchronizer based on the target action time and the target grid-side voltage data; Based on the target synchronization state, the virtual synchronizer is controlled to perform continuous state adjustment, and an action command is sent to the target circuit breaker when the preset action conditions are met; After the action command is sent, the action process data of the target circuit breaker is acquired, the continuous state of the virtual synchronous machine is adjusted based on the action process data, and the microgrid is controlled to complete the operation state switch when it is confirmed that the target circuit breaker has completed the actual electrical state switch.

[0009] To achieve the above objectives, the present invention also provides a microgrid virtual synchronous continuous switching control system, comprising: The historical data processing module is used to acquire industrial big data containing historical action data of the target circuit breaker and build an action delay feature library. The action timing determination module is used to respond to the microgrid switching command, acquire the current operating condition data of the target circuit breaker, and determine the target action timing based on the current operating condition data and the action delay feature library; The synchronization state determination module is used to acquire target grid-side voltage data and determine the target synchronization state of the virtual synchronizing machine based on the target action time and the target grid-side voltage data. The continuous control module is used to control the virtual synchronizer to perform continuous state adjustment based on the target synchronization state, and to send an action command to the target circuit breaker when the preset action conditions are met. The action tracking module is used to acquire the action process data of the target circuit breaker after the action command is sent, adjust the continuous state of the virtual synchronous machine based on the action process data, and control the microgrid to complete the operation state switch when it is confirmed that the target circuit breaker has completed the actual electrical state switch.

[0010] One or more technical solutions proposed in this application have at least the following technical effects: This application utilizes industrial big data to form the action delay characteristics of the target circuit breaker under different operating conditions, enabling virtual synchronous control to take into account the actual action time differences of the specific circuit breaker caused by changes in the operating environment and equipment status.

[0011] This application uses the lower and upper boundaries of the action delay to form the expected action period, and controls the virtual synchronizing machine to ensure that the start and end times of the expected action period are within the allowable synchronization range. At the same time, it keeps the phase difference in the same direction of change during the period. This allows the microgrid side and the grid side to remain in a suitable synchronization state when the target circuit breaker completes the main contact action at different actual times within the normal action delay range.

[0012] In this application, after the action command is issued, the completed mechanical action stage is identified by the status of the operating coil. Based on the actual stage duration, historical action data is re-filtered, and only the remaining action time range corresponding to the unfinished part is determined. This can reduce the problem of carrying the prediction error before the action into the entire mechanical action process.

[0013] In this application, under low switching power conditions, the virtual internal potential control of the virtual synchronous machine itself generates a limited test change, and the actual current response of the PCC branch is used to confirm whether the main circuit has been electrically connected. This can improve the reliability of the actual continuity determination and avoid adding an independent test power supply. Attached Figure Description

[0014] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0015] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a flowchart illustrating an embodiment of the microgrid virtual synchronous continuous switching control method of this application; Figure 2This is a schematic diagram of the data storage for the action delay feature library of this application; Figure 3 This is a schematic diagram illustrating the process of performing continuous state adjustment of the virtual synchronizer according to the expected action period in this application; Figure 4 This is a schematic diagram showing the timing relationship of the closing action of the target circuit breaker in a specific example of this application; Figure 5 This is a schematic diagram illustrating the relationship between the expected action time period and the phase difference change in a specific example of this application; Figure 6 This is a schematic diagram showing the relationship between the virtual internal potential change and the branch current response under low switching power conditions in a specific example of this application.

[0017] Figure 7 This is a schematic diagram of the microgrid virtual synchronous continuous switching control system structure in this application; The purpose, features, and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0018] It should be understood that the specific embodiments described herein are merely illustrative of the technical solutions of this application and are not intended to limit this application.

[0019] To better understand the technical solution of this application, a detailed description will be provided below in conjunction with the accompanying drawings and specific embodiments. The target circuit breaker described in this application can be an AC circuit breaker installed at the microgrid's point of common coupling for establishing or disconnecting the electrical connection between the microgrid and the upstream power grid, or it can be a tie switch performing the same switching function. The virtual synchronous machine can be implemented by an energy storage converter, or by other grid-type power electronic equipment with virtual synchronization control functions.

[0020] The main solution of this invention is as follows: Based on the industrial big data generated from the long-term operation of the microgrid, the operating delay range of the target circuit breaker under different actual operating conditions is obtained. The target operating time and the expected operating period are determined according to the current operating conditions. The virtual angular velocity and virtual internal potential of the virtual synchronous machine are adjusted to keep the entire expected operating period within the allowable synchronization range. After the target circuit breaker starts to execute the current action, the completed operation stage is identified according to the actual state of the operating coil. The historical operation data is re-filtered based on the actual stage duration, thereby determining the remaining operation time range corresponding to the uncompleted operation, and the virtual synchronous machine state is updated accordingly. Finally, the actual electrical state of the main circuit is used to confirm whether the microgrid has completed grid connection or off-grid switching.

[0021] It should be noted that the executing entity in this embodiment can be a microgrid central controller, energy management controller, energy storage converter controller, edge control device, or a control system composed of the above devices. The executing entity must at least have the capability to acquire electrical quantities, acquire switching quantities, record time, store data, process data, and output control commands to the virtual synchronizer and the target circuit breaker. The following description uses a microgrid control system as the executing entity.

[0022] Based on this, embodiments of the present invention provide a virtual synchronous continuous switching control method for microgrids. For example... Figure 1 As shown, in this embodiment, the full-dimensional network inertia field control method includes steps S100 to S500.

[0023] Step S100: Obtain industrial big data containing historical action data of the target circuit breaker and construct an action delay feature library.

[0024] In this embodiment of the invention, step S100 specifically includes: acquiring historical operation records of the target circuit breaker and historical operating condition data corresponding to each historical operation record, and associating the historical operation records with the historical operating condition data according to the same operation event to obtain historical action data; reading the action command time from each historical operation record, and determining the corresponding actual electrical switching time according to the branch current state and the voltage state on both sides of the circuit breaker; determining the time interval between the actual electrical switching time and the action command time as the historical action delay; classifying the historical action delay according to the action type and the preset operating condition interval corresponding to the historical operating condition data to obtain an action delay feature library.

[0025] It should be noted that historical operation records can be obtained from microgrid controllers, SCADA systems, protection devices, circuit breaker intelligent control units, and fault recording devices. Historical operation records can at least correspond to the target circuit breaker's operating command status, auxiliary contact status, branch current data, and voltage data across the circuit breaker. Historical operating condition data describes the actual equipment conditions under which the circuit breaker performed the operation, and can include operating power supply status, environmental conditions, and mechanical life status. Operating power supply status can be represented by DC operating power supply voltage or operating coil supply voltage; environmental conditions can be represented by the internal temperature of the switchgear or the temperature near the mechanism; and mechanical life status can be represented by the cumulative number of operations, the number of operations after maintenance, or the maintenance status.

[0026] As is easily understood, all of the above data can be obtained from existing microgrid field equipment. For example, the status of auxiliary contacts is a conventional switching quantity; the circuit breaker branch current and the voltage on both sides are basic electrical data that need to be collected during the microgrid's on-grid and off-grid control process; the DC operating power supply voltage can be obtained from a DC power supply panel or intelligent control device; and the cumulative number of actions can be obtained from the circuit breaker controller or maintenance management system. The industrial big data in this application is formed by the accumulation of a large number of actual circuit breaker action events and is directly used for the next virtual synchronous switching control.

[0027] In one feasible implementation, the control system uses a closing or opening command as the starting point of a historical action event, grouping data collected within a preset time range before and after the action command into the same operation event. For example, data from 100ms before the action command to 300ms after the action command is considered as a complete historical action record. For equipment with a long rated action time, the data retention time after the action command can be increased according to the equipment type.

[0028] For the i-th historical action event, the control system records the time of the action command and the actual electrical switching time, and determines the time interval between the two as the historical action delay, which can be represented by the following relationship: Δt i =t e,i -t c,i ; Where, Δt i t represents the historical action delay corresponding to the i-th historical action event. e,i t represents the actual electrical switching time corresponding to this historical action event. c,i This indicates the time of the action command corresponding to this historical action event.

[0029] Specifically, for closing operations with significant exchange current, after the auxiliary contacts indicate the closed position, the control system continuously monitors the branch current of the target circuit breaker. When the branch current continuously exceeds a preset current threshold for a preset duration, the moment when this condition is first met is determined as the actual conduction moment. Setting a preset duration can reduce erroneous judgments caused by abnormalities in a single sampling point or initial contact of the contacts. In one example, a 400V industrial microgrid can have the preset current threshold set to 2A and the preset duration set to 2ms. It should be noted that the actual values ​​can be determined based on the accuracy of the current sensor and the system capacity.

[0030] For closing events with low switching power in historical data, the actual historical conduction time can be determined by combining the auxiliary contact status and the voltage change relationship on both sides of the circuit breaker. The purpose of the historical data here is mainly to establish the initial characteristics of the action delay; for the confirmation of actual conduction with low switching power during subsequent online switching, the active testing method described in S500 of this application is preferred, thereby further improving the reliability of online status confirmation.

[0031] For the tripping operation, after the auxiliary contacts indicate the tripping position, when the branch current is continuously lower than the preset current threshold, and the phase difference change of the voltages on both sides of the circuit breaker exceeds the preset change threshold, the moment when the above conditions are first met is determined as the actual disconnection moment. The branch current is used to indicate that the main circuit current has been interrupted, and the voltage change relationship on both sides is used to further indicate that the direct electrical constraint of the upper-level power grid has been released on the microgrid side.

[0032] Furthermore, after processing multiple historical action events, historical data sets are formed separately for closing and opening, and action delay partitions are established according to preset operating condition dimensions. For example, the operating power supply voltage can be divided into low-temperature zone, normal zone, and high-temperature zone; the mechanism temperature can be divided into low-temperature zone, normal-temperature zone, and high-temperature zone; and the cumulative number of actions can be divided into initial zone, intermediate zone, and near-maintenance zone based on the equipment maintenance cycle.

[0033] Historical action delays within the same action delay partition are organized according to their numerical values. After deleting invalid action records caused by communication anomalies, sensor anomalies, or maintenance tests, the typical action delay, lower boundary of the action delay, and upper boundary of the action delay for that partition can be determined. The typical action delay can be represented by the median of the effective historical action delays; the lower boundary and upper boundary of the action delay can be determined based on the actual distribution of normal action data for that partition.

[0034] For example, the QF01 circuit breaker recorded 42 valid closing actions under normal operating voltage, normal temperature, and mid-term mechanical life conditions. Most of these actual closing delays were between 54ms and 61ms. Therefore, 54ms can be saved as the lower boundary of the action delay, 61ms as the upper boundary, and 57ms as the typical action delay. All three sets of data correspond to the same circuit breaker, the same action type, and the same operating condition zone.

[0035] Furthermore, this application can also save the operating coil state data in each historical action event. The operating coil state data is preferably continuous current sampling data of the closing coil or opening coil, and coil voltage can also be saved simultaneously. After the operation command is issued, the coil current starts to build up from near zero. As the coil magnetic field is established, the iron core moves, and the operating mechanism moves, its rate and direction of change exhibit repeatable phased changes. Therefore, based on the moment when the coil current begins to build up and the moment when preset characteristic changes occur, the historical action delay can be further represented as the duration of several continuous action phases for use in determining the remaining action time in S500.

[0036] like Figure 2 As shown, in practical applications, the action delay feature library can be stored in the form of circuit breaker number, action type, operating condition zone, typical action delay, lower boundary of action delay, upper boundary of action delay, and duration of each action stage. The above data structure is only used to illustrate the correspondence between the data; the actual database fields can be set according to the specific control platform.

[0037] Step S200: In response to the microgrid switching command, obtain the current operating condition data of the target circuit breaker, and determine the target action time based on the current operating condition data and the action delay feature library.

[0038] In this embodiment of the invention, step S200 specifically includes: determining the action type of the target circuit breaker according to the microgrid switching instruction, and obtaining the current operating condition data corresponding to the action type; matching the current operating condition data with the preset operating condition interval in the action delay feature library, and reading the predicted action delay corresponding to the matched operating condition interval; determining the sum of the current time and the preset continuous adjustment duration as the action command reference time; and determining the sum of the action command reference time and the predicted action delay as the target action time.

[0039] Further, the step of matching the current operating condition data with the preset operating condition intervals in the action delay feature library and reading the predicted action delay corresponding to the matched operating condition interval includes: placing the current operating condition data into the corresponding current operating condition intervals according to the preset operating condition dimensions; filtering action delay partitions that are the same type of action and match all current operating condition intervals, and determining the typical action delay in the action delay partition as the predicted action delay; when there is no action delay partition that matches all current operating condition intervals, selecting adjacent action delay partitions according to the difference between the current operating condition data and the boundary of the adjacent operating condition interval, and determining the longer typical action delay in the adjacent action delay partition as the predicted action delay.

[0040] Specifically, when the energy management system issues an off-grid to on-grid switching command, the action type of the target circuit breaker is determined to be closing; when the energy management system issues an on-grid to off-grid switching command, the action type is determined to be opening. Subsequently, the current operating power supply voltage, current mechanism temperature, cumulative number of actions, and maintenance status are read to form the current operating condition data.

[0041] In one executable implementation, assuming the target circuit breaker is QF01, the current closing operation is performed with an operating power supply voltage of 218V, a temperature near the mechanism of 18℃, and a cumulative number of operations of 426. The control system determines that the above operating conditions belong to the normal operating voltage zone, the normal temperature zone, and the mid-term mechanical life zone, respectively, and finds the corresponding closing operation delay zone from the operation delay feature library.

[0042] When the typical action delay of this action delay partition is 57ms, 57ms will be used as the predicted action delay for this time. At the same time, S400 will also use the 54ms lower boundary of action delay and the 61ms upper boundary of action delay in this partition to further form the expected action period.

[0043] It should be noted that the preset continuous adjustment duration is used to provide the virtual synchronizer with time to gradually approach the future synchronization state from the current state. In one implementation, it can be set to 80ms; this time can be shortened when the phase, frequency, and voltage amplitude of the microgrid side and the grid side are already relatively close. The preset continuous adjustment duration is a preset parameter and can be determined by the allowed frequency change rate, voltage adjustment rate, and microgrid grid connection response requirements of the virtual synchronizer.

[0044] The timing of the target action can be determined according to the following relationship: t g =t r +t p +Δt p ; Among them, t g t represents the target operating time when the target circuit breaker is expected to complete the actual electrical state switching. r Indicates the current time, t p Indicates the preset continuous adjustment duration, Δt p This represents the predicted action delay corresponding to the current operating condition. t r With t p The sum corresponds to the reference time of the action command.

[0045] It should be noted that the target operating time in this application is used to obtain a future electrical state that can represent the central position during the current mechanical operation, and does not require the target circuit breaker to necessarily complete operation at that single moment. The target circuit breaker may complete actual operation at any time between the lower boundary and the upper boundary of the operating delay, and then the two boundaries are further used in S400 to form the expected operating period.

[0046] Step S300: Obtain target grid-side voltage data, and determine the target synchronization state of the virtual synchronizing machine based on the target action time and the target grid-side voltage data.

[0047] In this embodiment of the invention, step S300 specifically includes: collecting target grid-side voltage data within a preset sampling period; determining the grid period and grid frequency based on adjacent zero-crossing times; and determining the grid voltage amplitude based on the target grid-side voltage data; advancing the current grid phase along the current rotation direction to the target action time based on the remaining time from the current time to the target action time and the grid period to obtain the target phase; and determining the target synchronization state based on the target phase, the grid frequency, and the grid voltage amplitude.

[0048] Specifically, the target grid voltage data can be collected by a three-phase voltage sensor installed on the grid side upstream of the target circuit breaker. For a 50Hz AC microgrid, the five most recent complete AC cycles can be selected as the preset sampling period. The grid cycle is determined based on the consecutive zero-crossing times of phase A voltage in the same direction, and the current grid frequency is obtained. At the same time, the grid voltage amplitude is determined based on the effective value of the three-phase voltage.

[0049] During the sampling period, if the change between adjacent power grid cycles exceeds the preset cycle change threshold, or the voltage amplitude change exceeds the preset voltage change threshold, a new preset sampling period can be acquired and the action command reference time can be postponed to ensure that the data used to predict future states can reflect the current power grid operation.

[0050] For the target phase, when the grid frequency changes little over a short period of time, it can be explained according to the following simple relationship: θ g =θ0+360×f×(t g -t0); Where, θ g θ0 represents the target phase corresponding to the target action time t0, f represents the current grid frequency, and t represents the grid phase corresponding to the current sampling time t0. g Indicates the moment of the target action. Time is expressed in seconds, 360 × f × (t) g -t0) represents the phase angle that the power grid is expected to continue rotating through in the remaining time.

[0051] It should be noted that the phase advancement in this application is used for short-term predictions in the range of tens to hundreds of milliseconds. When the grid frequency change exceeds a preset frequency change threshold, the target phase can be redefined using the latest grid cycle. The target synchronization state obtained from the target phase, grid frequency, and grid voltage amplitude will serve as an intermediate target for the continuous state adjustment of the S400.

[0052] Step S400: Based on the target synchronization state, control the virtual synchronizer to perform continuous state adjustment, and send an action command to the target circuit breaker when the preset action conditions are met.

[0053] like Figure 3 As shown in the embodiment of the present invention, step S400 specifically includes: reading the lower boundary and upper boundary of the action delay corresponding to the matching operating condition interval, and determining the expected action period in combination with the action command reference time; obtaining the current synchronization state of the virtual synchronizer, and determining the synchronization deviation data based on the current synchronization state and the target synchronization state; adjusting the virtual angular velocity and virtual internal potential according to the synchronization deviation data so that the synchronization deviations corresponding to the start and end times of the expected action period are both within a preset synchronization range, and the phase difference maintains the same direction of change within the expected action period; and sending an action command to the target circuit breaker when the preset synchronization range is met.

[0054] It should be noted that the expected action period is used to represent the time range within which the target circuit breaker may complete the actual electrical state switch after the action command is issued, based on historical normal operation conditions corresponding to the current operating conditions. The control system adds the action command reference time to the lower boundary of the action delay to obtain the start point of the expected action period; and adds the action command reference time to the upper boundary of the action delay to obtain the end point of the expected action period.

[0055] For example, if the reference time for the action command is 10:00:00.080, the lower boundary of the action delay in the matching operating condition range is 54ms, and the upper boundary of the action delay is 61ms, then the expected action period is from 10:00:00.134 to 10:00:00.141. This time range is used to characterize the actual historical operation of the circuit breaker under the same or similar operating conditions. It is highly probable that the main contacts will complete conduction within the specified 7ms range.

[0056] The control system predicts the upstream grid phases corresponding to the start and end points of the expected action period, and compares the current virtual phase, virtual angular velocity, and output voltage amplitude of the virtual synchronizer with the expected state. The synchronization deviation data may include phase deviation, frequency deviation, and voltage amplitude deviation.

[0057] Specifically, when the microgrid-side phase lags behind the grid-side phase throughout the expected operating period, the virtual angular velocity can be slightly increased to gradually reduce the phase difference; conversely, when the microgrid-side phase leads, the virtual angular velocity can be slightly decreased. The adjustment process maintains continuous virtual angular velocity, and the maximum allowable frequency variation between adjacent control cycles can be set. For example, the virtual frequency adjustment for a single control cycle can be limited to within 0.02Hz, with the actual value set based on the converter capacity and the allowable frequency variation range of the load.

[0058] Regarding voltage amplitude, when the microgrid-side voltage is lower than the target grid-side voltage, the virtual internal potential is gradually increased; when the microgrid-side voltage is higher than the target grid-side voltage, the virtual internal potential is gradually decreased. The change in virtual internal potential per cycle can also be set with an upper limit, thus ensuring continuous voltage changes during the expected operating period.

[0059] This application further requires that the synchronization deviations corresponding to the start and end points of the expected operating period be within a preset synchronization range. For example, the phase difference threshold can be set to 5°, the frequency difference threshold to 0.1Hz, and the voltage amplitude difference to 5% of the rated voltage. Only when the expected synchronization states at the start and end points of the expected operating period meet the above conditions is it considered that the target circuit breaker can meet the basic synchronization requirements by completing its operation at either the earlier or later time within the normal operating time range.

[0060] Furthermore, the control system maintains the phase difference in the same direction of change throughout the expected operating period. For example, when the microgrid-side voltage phase lags slightly behind the grid-side at the start of the expected operating period, the virtual synchronizer is controlled to continuously reduce the phase difference from the start to the end, or keep it near zero. This approach allows the phase change within the expected operating period to be limited by the states at both the start and end points, reducing synchronization differences caused by the target circuit breaker completing conduction at different actual times within the stated time range.

[0061] In one implementation, the phase difference at the start of the expected action period is 2.8°, the phase difference at the end is 0.9°, and the phase difference between the two continues to decrease; the corresponding frequency difference and voltage amplitude difference are also within a preset synchronization range, then a closing command is allowed to be issued at the action command reference time. If the start of the expected action period meets the synchronization range but the phase difference at the end reaches 7°, then the virtual angular velocity is adjusted further, no closing command is sent, and the reference time for subsequent action commands is re-determined using the new current time.

[0062] Therefore, this application expands the object controlled before the action command is issued from a single predicted action time to the expected action period, and utilizes the adjustable virtual angular velocity of the virtual synchronizing machine to form a continuous and usable synchronization time range, which can adapt to the situation where the actual mechanical action time of the target circuit breaker still varies under the same operating conditions.

[0063] For the grid-connected to off-grid transition process, the lower and upper boundaries of the action delay correspond to the expected actual disconnection period. Before this period arrives, the control system maintains continuous virtual phase and virtual angular velocity, and simultaneously generates a virtual mechanical power reserve value for use after disconnection based on the local load within the microgrid. A tripping command is only sent when both the start and end times of the expected actual disconnection period meet the preset takeover conditions.

[0064] Step S500: After the action command is sent, the action process data of the target circuit breaker is obtained, the continuous state of the virtual synchronous machine is adjusted based on the action process data, and when it is confirmed that the target circuit breaker has completed the actual electrical state switching, the microgrid is controlled to complete the operation state switching.

[0065] In this embodiment of the invention, step S500 specifically includes: after the action command is sent, collecting operation coil status data, and determining the completed action stage and its actual stage duration based on the start change time and preset characteristic change time of the operation coil status data; filtering historical action data from the action delay feature library whose actual stage duration is within a preset difference range, and determining the remaining action time range based on the remaining stage duration of the filtered historical action data; updating the expected action period and target synchronization state based on the remaining action time range, and continuing to adjust the virtual synchronizer based on the updated target synchronization state; acquiring switch position status data and branch electrical status data, and when confirming that the target circuit breaker has completed the actual electrical state switch, retaining the current internal state of the virtual synchronizer and controlling the microgrid to complete the operating state switch.

[0066] It should be noted that the operating coil status data preferably uses the closing coil current or opening coil current, which can be obtained at a higher sampling frequency. After the target circuit breaker receives the closing command, the operating circuit first supplies power to the closing coil, and the coil current begins to increase from near zero. After the coil generates sufficient electromagnetic force, the iron core and the operating mechanism connected to it begin to move. The coil inductance and circuit state change with the mechanical position, so the rate or direction of change of the coil current will show a identifiable change.

[0067] In one executable implementation, two characteristic moments can be pre-determined from the historical operating data of the target circuit breaker: the first characteristic moment is when the coil current continuously exceeds a preset coil current threshold, indicating that the operating coil has begun to be effectively energized; the second characteristic moment is when the coil current rise rate changes from being greater than a preset rate of change to being less than a preset rate of change and remains so for a preset time, indicating that the core or operating mechanism has entered the subsequent movement stage. The operating coil current characteristics may differ between different circuit breaker models; therefore, the characteristic judgment conditions can be determined according to the historical effective operating data of the corresponding equipment.

[0068] This embodiment can divide the target circuit breaker's operation process into at least three stages: from command output to coil energization, from coil energization to mechanism entry into motion, and from mechanism movement to actual electrical switching. This stage division indicates the actual progress of the mechanical action and does not require all circuit breaker models to use the exact same number of stages. In devices capable of obtaining data from mechanism limit switches or displacement sensors, the corresponding mechanical position data can be used to further refine the operation stages.

[0069] Once the first characteristic moment is detected, the actual duration of the first action phase can be obtained; upon further detection of the second characteristic moment, the actual duration of the second action phase can be obtained. The control system compares the currently obtained actual phase durations with historical action events in the action delay feature library.

[0070] Specifically, assuming the actual duration from the issuance of the action command to the effective energization of the coil is 5ms, and the duration from the effective energization of the coil to the second characteristic moment is 8ms, and the preset difference range is set to ±2ms, then historical action events with the first action phase between 3ms and 7ms and the second action phase between 6ms and 10ms are selected from the historical action data in the current matching working condition partition. This selection process further utilizes historical samples that closely resemble the actual mechanical process that has already occurred to determine the remaining action time.

[0071] For the filtered historical action events, only the remaining stage duration from the characteristic moment corresponding to the current action stage to the actual electrical switching moment is read. For example, if the original matching condition partition has 42 valid historical action records, and 16 records remain after filtering based on the actual stage duration, and the remaining stage duration from the second characteristic moment to the actual conduction of the main contact is between 40ms and 44ms, then 40ms to 44ms is determined as the new remaining action time range.

[0072] It is easy to understand that the remaining action time range is the data obtained again based on the actual action after the action command has been issued. It has a different meaning from the total action time range obtained based on the current operating conditions before the action occurs in S200. The former is used to indicate how much time the target circuit breaker needs to complete the remaining mechanical process after it has completed the current action stage.

[0073] The control system adds the current time to the lower boundary of the remaining action time range to obtain the updated predicted start point of the action period; it adds the current time to the upper boundary of the remaining action time range to obtain the updated predicted end point of the action period. Then, it re-determines the grid phase corresponding to the two future times based on the current target grid voltage data and updates the target synchronization state.

[0074] Furthermore, after updating the expected action period, the virtual angular velocity and virtual internal potential are adjusted according to the same control principles as S400, ensuring that the synchronization deviation of the start and end times of the updated expected action period are within the preset synchronization range, and that the phase difference maintains the same direction of change within the updated period. Thus, information that has actually occurred during this mechanical action can directly change the VSG control state of subsequent grid-connected operations.

[0075] In one scenario, the expected action timeframe before the action is initiated is 54ms to 61ms, but the coil energization and the initial movement of the mechanism are both faster than the corresponding historical typical state. After actual stage screening, the new remaining action time range is 38ms to 41ms. The control system then updates the expected actual conduction timeframe accordingly to prevent the virtual synchronizer from continuing to adjust the phase based on the original typical action delay of 57ms.

[0076] In another scenario, the power supply voltage drops briefly during this operation, causing the operating coil current to build up and the front-end movement of the mechanism to slow down significantly. After screening based on the actual stage, the new remaining action time range is found to be 45ms to 50ms. Therefore, the expected actual conduction period is updated and the speed at which the virtual phase moves towards the optimal synchronization position is appropriately slowed down so that the synchronization state can cover the delayed mechanical action process.

[0077] Upon detecting a change in switch position status data, the control system further collects branch electrical status data and performs actual electrical status switching confirmation. Switch position status data can be obtained from the closed auxiliary contact and the open auxiliary contact. Branch electrical status data includes at least the target circuit breaker branch current and may also include the three-phase voltages on both sides of the circuit breaker.

[0078] When the current action is closing and there is significant power exchange after actual grid connection, if the branch current continuously exceeds the preset current threshold for a preset duration after the closing auxiliary contact has indicated the closing position, then the main circuit is confirmed to have completed actual conduction. For example, a branch current entering a continuous AC state from a near-zero state and continuously exceeding 2A for 2ms can be used as a specific implementation condition.

[0079] When the current action involves closing the circuit breaker and the auxiliary contact indicating that the circuit is closed, but the branch current is still lower than the preset current threshold, the control system enters the low-power switching confirmation process. A preset test increment is applied to the current virtual internal potential of the virtual synchronous machine, causing the microgrid-side output voltage to undergo a short-term change with limited amplitude and duration within the allowable range.

[0080] Specifically, in a 400V microgrid, the preset test increment can be set to 0.5% of the current virtual internal potential, and the test duration can be set to 4ms. These values ​​are less than the allowable voltage variation range for normal grid connection and can be determined in practical applications based on the microgrid load sensitivity and converter control cycle. Before applying the test increment, the control system records the average amplitude of the branch current within a preset reference time period; during the application of the test increment, the change in branch current is continuously recorded.

[0081] If a real electrical connection has been established with the main contacts, short-term changes in the virtual internal potential will generate corresponding changes in branch current through the equivalent impedance on the microgrid side and the grid connection path. Therefore, when the change in branch current relative to the pre-test baseline state reaches a preset response threshold during the test, and the change continues for a preset test response time, it can be confirmed that the target circuit breaker has completed actual conduction.

[0082] In one feasible implementation, the preset response threshold can be set to 1% of the rated branch current, and the preset test response time can be set to 2ms. If, after the virtual internal potential increases by 0.5%, the branch current increases by more than 1% of the rated current and remains so for 2ms within the test time, it is confirmed that the main circuit has been electrically connected. After confirmation, the virtual internal potential is immediately restored to the reference state that should have been used before the test according to the synchronization control process.

[0083] If the branch current change does not reach the preset response threshold during the test, the main circuit is not confirmed to be actually conducting. The virtual synchronous control state is maintained, and the system continues to wait based on the updated expected action period or is tested again according to the equipment's allowable conditions. This method avoids directly considering the main circuit as having completed electrical conduction when the auxiliary contacts are already closed and the voltages on both sides are already in a pre-synchronous state.

[0084] It should be noted that the test increment is achieved through the existing virtual internal potential control channel of the virtual synchronizer. The test amplitude and duration are both kept within the allowable range of the normal voltage of the microgrid, and it is preferably used when the closing auxiliary contact has changed and the ordinary branch current determination cannot obtain a clear result.

[0085] When the action is to trip, after the trip auxiliary contact indicates the trip position, if the branch current is continuously lower than the preset current threshold, and the change in the phase difference of the voltage on both sides of the circuit breaker exceeds the preset change threshold, then it is confirmed that the target circuit breaker has completed actual disconnection. At this time, the voltage on the microgrid side can change independently according to the state of the virtual synchronous machine itself, and the moment of actual disconnection confirmation can be taken as the time when the off-grid control is officially taken over.

[0086] After confirming that the target circuit breaker has completed its actual conduction or actual disconnection, the control system maintains the current virtual power angle, virtual angular velocity, and virtual internal potential of the virtual synchronous machine continuously. For grid-connected processes, the additional control quantities used for pre-switching synchronization adjustments can be gradually reduced over several control cycles to allow normal grid-connected power regulation to continue operating; for off-grid processes, a pre-established local power takeover state is used to maintain the microgrid voltage and frequency.

[0087] If the actual electrical state transition is not confirmed after the end of the current expected operating period, an abnormal circuit breaker operation status can be output, and the virtual synchronous machine can be kept within the preset safe operating range. The final operating state of the microgrid will not be directly modified based on operating commands or changes in a single auxiliary contact until the actual conduction or disconnection of the main circuit is confirmed.

[0088] After each action is completed, the time of the action command, the time of each characteristic of the operating coil, the time of change of the auxiliary contacts, the time of actual electrical switching, and the current operating condition data are re-formed into a historical action record and written into the industrial big data. When the action delay feature library is reorganized in subsequent operations, the data of this action can be used as a new valid sample, so that the action delay range and the time range of each stage are gradually updated as the equipment operating status changes.

[0089] The following is a complete set of specific examples illustrating the entire process of expected action period control, current action phase update, and low switching power conduction confirmation.

[0090] Assuming the microgrid's rated line voltage is 400V and rated frequency is 50Hz, the target circuit breaker is QF01, and the grid-connecting equipment is a 500kW / 1MWh energy storage converter. QF01 has stored 126 historical closing records and 94 historical opening records. Within the closing condition zone corresponding to operating power supply of 210V to 225V, mechanism temperature of 0℃ to 35℃, and cumulative action count of 300 to 600 times, there are 42 valid historical action events. The lower boundary of the action delay is 54ms, the upper boundary of the action delay is 61ms, and the typical action delay is 57ms.

[0091] like Figure 4 As shown, the microgrid was in an off-grid state at this time, and the energy management system issued a grid connection switching command at 10:00:00.000. At this time, the QF01 operating power supply voltage was 218V, the mechanism temperature was 18℃, and the cumulative number of actions was 426, matching the above-mentioned historical action partition. The control system is set to a preset continuous adjustment time of 80ms, so the reference time for the action command is 10:00:00.080, and the target action time obtained based on a typical action delay of 57ms is 10:00:00.137.

[0092] Based on the lower boundary of the 54ms action delay and the upper boundary of the 61ms action delay, the control system obtains the initial expected action period as 10:00:00.134 to 10:00:00.141. This time range represents the normal time range within which QF01 can potentially complete actual conduction under current operating conditions, based on historical valid data.

[0093] The control system acquires the three-phase voltage of the upstream power grid over the last 100ms, obtaining a grid frequency of approximately 50.01Hz and an effective line voltage of approximately 401V. At this time, the virtual synchro frequency on the microgrid side is approximately 49.96Hz, and the effective line voltage is approximately 397V. Based on the expected start and end points of the operating period, the grid phase is predicted, and the virtual angular velocity and virtual internal potential are gradually increased.

[0094] like Figure 5 As shown, when the action command reference time is reached at 10:00:00.080, the predicted phase difference at the start of the action period is approximately 2.6°, and the predicted phase difference at the end of the action period is approximately 0.8°, with the phase difference decreasing between the two times; the predicted frequency difference is less than 0.05Hz, and the predicted voltage amplitude difference is less than 2%. These results are within the preset synchronization range, therefore, the QF01 closing command is sent.

[0095] After the closing command is sent, the closing coil current begins to be recorded at a higher sampling frequency. For example... Figure 4As shown, the control system detects that the coil current continuously exceeds the preset coil current threshold at 10:00:00.085, determining that the coil has started to be effectively energized; at 10:00:00.094, it detects that the coil current rise rate has reached the preset change condition, determining that the mechanism enters the subsequent action stage. Therefore, the actual duration from the action command to the effective energization stage of the coil is 5ms, and the actual duration of the next stage is 9ms.

[0096] The control system further filters historical action events from the current 42 historical action events, selecting those where the difference between the duration of the first stage and 5ms is no more than 2ms, and the difference between the duration of the second stage and 9ms is no more than 2ms, resulting in 14 historical records. The remaining duration of these 14 records from the second characteristic moment to actual conduction is between 40ms and 43ms.

[0097] Therefore, with 10:00:00.094 as the new current action phase time, the updated estimated actual conduction period is determined to be from 10:00:00.134 to 10:00:00.137. Compared to the initial estimated action period of 10:00:00.134 to 10:00:00.141, the updated action period ends 4ms earlier, indicating that the remaining time range can be further narrowed based on the initial state of the actual mechanical action.

[0098] The control system recalculates the target grid phases corresponding to the two times 10:00:00.134 and 10:00:00.137, and continues to adjust the virtual angular velocity according to the new expected action period, so that the phase difference between the two ends is about 1.5° and 0.7° respectively, and the same direction of change is maintained in the middle.

[0099] At 10:00:00.135, the QF01 closed auxiliary contact changes. In this example, the grid-connected power is set to be close to zero, and the branch current is still below 2A. Therefore, the ordinary effective current criterion cannot directly confirm that the main circuit has been established.

[0100] like Figure 6 As shown, after confirming the change in the closed auxiliary contact, the control system increases the virtual internal potential by 0.5% based on the original synchronous control reference value and maintains it for 4ms. Before the test starts, the average amplitude of the branch current is about 0.6A; about 1ms after the test starts, the branch current increases to around 3.1A and maintains an effective response corresponding to the test change for the next 2ms, exceeding the preset response threshold.

[0101] Therefore, the control system confirms that the QF01 main circuit has actually been turned on, and records the moment when the test response first stably meets the conditions as the actual electrical turn-on moment. Subsequently, the virtual internal potential is restored to the reference state that should be used according to normal grid-connected control, while maintaining the current virtual power angle and virtual angular velocity continuously.

[0102] The microgrid's operating status is updated from off-grid to grid-connected, and in subsequent control cycles, the additional phase adjustments during the switching period are gradually phased out, with normal active and reactive power control taking over. The actual duration of this action, the actual turn-on time, and the test response data are all saved to the corresponding historical action record.

[0103] In this application example, the initial industrial big data first provides the possible time range of the target circuit breaker's operation, and the virtual synchronizing machine establishes a synchronization state covering this time range accordingly. After the operation command is issued, the remaining operation time range is narrowed down by using the actual mechanical operation stage reflected by the current coil current. When the branch exchange current is insufficient to directly confirm the actual conduction, the branch response that can be actually measured is generated by the virtual internal potential limitation change.

[0104] This application also provides a microgrid virtual synchronous continuous switching control system; please refer to [reference needed]. Figure 7 The microgrid virtual synchronous continuous switching control system includes: Historical data processing module 10 is used to acquire industrial big data containing historical action data of the target circuit breaker and build an action delay feature library; The action timing determination module 20 is used to respond to the microgrid switching command, acquire the current operating condition data of the target circuit breaker, and determine the target action timing based on the current operating condition data and the action delay feature library; Synchronization state determination module 30 is used to acquire target grid side voltage data and determine the target synchronization state of the virtual synchronizer based on the target action time and the target grid side voltage data. The continuous control module 40 is used to control the virtual synchronizer to perform continuous state adjustment based on the target synchronization state, and to send an action command to the target circuit breaker when the preset action conditions are met. The action tracking module 50 is used to acquire the action process data of the target circuit breaker after the action command is sent, adjust the continuous state of the virtual synchronous machine based on the action process data, and control the microgrid to complete the operation state switch when it is confirmed that the target circuit breaker has completed the actual electrical state switch.

[0105] The microgrid virtual synchronous continuous switching control system provided in this application adopts the microgrid virtual synchronous continuous switching control method in the above embodiments. Compared with the prior art, the beneficial effects of the microgrid virtual synchronous continuous switching control system provided in this application are the same as the beneficial effects of the microgrid virtual synchronous continuous switching control method provided in the above embodiments, and other technical features in the microgrid virtual synchronous continuous switching control system are the same as the features disclosed in the methods of the above embodiments, and will not be repeated here.

[0106] The modules described in the embodiments of this application can be implemented in software or hardware. The names of the modules do not necessarily limit the functionality of the unit itself.

[0107] The above description is only a part of the embodiments of this application and does not limit the patent scope of this application. All equivalent structural transformations made under the technical concept of this application and using the contents of the specification and drawings of this application, or direct or indirect applications in other related technical fields, are included in the patent protection scope of this application.

Claims

1. A virtual synchronous continuous switching control method for microgrids, characterized in that, The method includes the following steps: Acquire industrial big data containing historical action data of the target circuit breaker and construct an action delay feature library; In response to a microgrid switching command, the current operating condition data of the target circuit breaker is obtained, and the target action time is determined based on the current operating condition data and the action delay feature library. Acquire target grid-side voltage data, and determine the target synchronization state of the virtual synchronizer based on the target action time and the target grid-side voltage data; Based on the target synchronization state, the virtual synchronizer is controlled to perform continuous state adjustment, and an action command is sent to the target circuit breaker when the preset action conditions are met; After the action command is sent, the action process data of the target circuit breaker is acquired, the continuous state of the virtual synchronous machine is adjusted based on the action process data, and the microgrid is controlled to complete the operation state switch when it is confirmed that the target circuit breaker has completed the actual electrical state switch.

2. The microgrid virtual synchronous continuous switching control method as described in claim 1, characterized in that, The steps for acquiring industrial big data containing historical action data of target circuit breakers and constructing an action delay feature library include: Obtain the historical operation records of the target circuit breaker and the historical operating condition data corresponding to each historical operation record, and associate the historical operation records with the historical operating condition data according to the same operation event to obtain historical action data; Read the timing of the action command from each historical operation record, and determine the corresponding actual electrical switching timing based on the branch current status and the voltage status on both sides of the circuit breaker. The time interval between the actual electrical switching time and the action command time is determined as the historical action delay; The historical action delays are classified according to the action type and the preset working condition interval corresponding to the historical working condition data to obtain an action delay feature library.

3. The microgrid virtual synchronous continuous switching control method as described in claim 2, characterized in that, The steps for retrieving the action command time from each historical operation record and determining the corresponding actual electrical switching time based on the branch current status and the voltage status on both sides of the circuit breaker include: For the closing operation, after the auxiliary contact indicates the closed position, if the branch current continuously exceeds the preset current threshold for a preset duration, the moment when the condition is first met is determined as the actual conduction moment. If the branch current does not continuously exceed the preset current threshold, the actual conduction time is determined according to the moment when the phase difference and frequency difference of the voltages on both sides of the circuit breaker are continuously less than their respective preset thresholds after the auxiliary contact indicates the closed position. For the tripping operation, after the auxiliary contact indicates the tripping position, the actual separation time is determined based on the moment when the branch current is continuously lower than the preset current threshold and the phase difference change of the voltage on both sides of the circuit breaker exceeds the preset change threshold.

4. The microgrid virtual synchronous continuous switching control method as described in claim 1, characterized in that, In response to a microgrid switching command, the steps of acquiring the current operating condition data of the target circuit breaker and determining the target action time based on the current operating condition data and the action delay feature library include: The action type of the target circuit breaker is determined according to the microgrid switching command, and the current operating condition data corresponding to the action type is obtained; The current working condition data is matched with the preset working condition interval in the action delay feature library, and the predicted action delay corresponding to the matched working condition interval is read. The sum of the current time and the preset continuous adjustment duration is determined as the reference time for the action command; The sum of the action command reference time and the predicted action delay is determined as the target action time.

5. The microgrid virtual synchronous continuous switching control method as described in claim 4, characterized in that, The step of matching the current operating condition data with the preset operating condition intervals in the action delay feature library and reading the predicted action delay corresponding to the matched operating condition interval includes: The current operating condition data is placed into the corresponding current operating condition interval according to the preset operating condition dimensions; Filter the action delay partitions that are the same as the action type and match all the current working condition intervals, and determine the typical action delay in the action delay partition as the predicted action delay; When there is no action delay partition that matches all the current operating condition intervals, the adjacent action delay partitions are selected according to the difference between the current operating condition data and the boundary of the adjacent operating condition intervals, and the longer typical action delay in the adjacent action delay partitions is determined as the predicted action delay.

6. The microgrid virtual synchronous continuous switching control method as described in claim 1, characterized in that, The steps of acquiring target grid-side voltage data and determining the target synchronization state of the virtual synchronizing machine based on the target action time and the target grid-side voltage data include: Collect target grid-side voltage data within a preset sampling period, determine the grid period and grid frequency based on adjacent zero-crossing times, and determine the grid voltage amplitude based on the target grid-side voltage data; Based on the remaining time from the current moment to the target action moment and the power grid cycle, the current power grid phase is advanced along the current rotation direction to the target action moment to obtain the target phase; The target synchronization state is determined based on the target phase, the grid frequency, and the grid voltage amplitude.

7. The microgrid virtual synchronous continuous switching control method as described in claim 4, characterized in that, The steps of controlling the virtual synchronizer to perform continuous state adjustment based on the target synchronization state, and sending an action command to the target circuit breaker when the preset action conditions are met, include: Read the lower boundary and upper boundary of the action delay corresponding to the matching working condition interval, and determine the expected action period in combination with the action command reference time; Obtain the current synchronization state of the virtual synchronizer, and determine the synchronization deviation data based on the current synchronization state and the target synchronization state; The virtual angular velocity and virtual internal potential are adjusted according to the synchronization deviation data so that the synchronization deviations corresponding to the start and end times of the expected action period are all within the preset synchronization range, and the phase difference maintains the same direction of change within the expected action period. When the preset synchronization range is met, an action command is sent to the target circuit breaker.

8. The microgrid virtual synchronous continuous switching control method as described in claim 7, characterized in that, After the action command is sent, the action process data of the target circuit breaker is acquired. Based on the action process data, the continuous state of the virtual synchronous machine is adjusted. When it is confirmed that the target circuit breaker has completed the actual electrical state switch, the microgrid is controlled to complete the operation state switch. The steps include: After the action command is sent, the operation coil status data is collected, and the completed action stage and its actual stage duration are determined based on the start change time and preset characteristic change time of the operation coil status data. Historical action data whose actual stage duration falls within a preset difference range are selected from the action delay feature library, and the remaining action time range is determined based on the remaining stage duration of the selected historical action data. The expected action period and target synchronization status are updated based on the remaining action time range, and the virtual synchronization machine is further adjusted according to the updated target synchronization status. Acquire switch position status data and branch electrical status data. When it is confirmed that the target circuit breaker has completed the actual electrical status switch, retain the current internal state of the virtual synchronous machine and control the microgrid to complete the operation status switch.

9. The microgrid virtual synchronous continuous switching control method as described in claim 8, characterized in that, When confirming that the target circuit breaker has completed the actual electrical state switch, the steps of retaining the current internal state of the virtual synchronous machine and controlling the microgrid to complete the operating state switch include: When the action type is closing and the branch current continuously exceeds the preset current threshold, the target circuit breaker is confirmed to have completed actual conduction by combining the switch position status data. When the action type is closing, the switch position status data indicates closing, and the branch current is lower than the preset current threshold, a preset test increment is applied to the virtual internal potential, and the target circuit breaker is confirmed to have completed actual conduction based on the change in branch current during the test reaching the preset response threshold. When the action type is tripping, the target circuit breaker is confirmed to have completed actual disconnection based on the switch position status data, the branch current being continuously lower than the preset current threshold, and the phase difference change of the voltage on both sides of the circuit breaker exceeding the preset change threshold. After confirming actual conduction or actual disconnection, the virtual power angle, virtual angular velocity, and virtual internal potential of the virtual synchronous machine are kept continuous, and the microgrid is controlled to enter the corresponding grid-connected or off-grid operation.

10. A virtual synchronous continuous switching control system for a microgrid, characterized in that, The system includes: The historical data processing module is used to acquire industrial big data containing historical action data of the target circuit breaker and build an action delay feature library. The action timing determination module is used to respond to the microgrid switching command, acquire the current operating condition data of the target circuit breaker, and determine the target action timing based on the current operating condition data and the action delay feature library; The synchronization state determination module is used to acquire target grid-side voltage data and determine the target synchronization state of the virtual synchronizing machine based on the target action time and the target grid-side voltage data. The continuous control module is used to control the virtual synchronizer to perform continuous state adjustment based on the target synchronization state, and to send an action command to the target circuit breaker when the preset action conditions are met. The action tracking module is used to acquire the action process data of the target circuit breaker after the action command is sent, adjust the continuous state of the virtual synchronous machine based on the action process data, and control the microgrid to complete the operation state switch when it is confirmed that the target circuit breaker has completed the actual electrical state switch.

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