A method, device, storage medium and computing equipment for adaptive protection of intelligent distribution network based on synchronized phasor data

Abstract

This invention discloses an adaptive protection method, device, storage medium, and computing equipment for intelligent distribution networks based on synchronized phasor data. The method collects synchronized phasor data frames monitored by the synchronized phasor measurement unit through a local phasor data concentrator. It calculates the average amplitude deviation and frequency deviation based on the synchronized phasor data frames at the current moment, and calculates an interference counter based on the average amplitude deviation and frequency deviation. The interference counter is used to identify islanding and faults; if an islanding is detected, an islanding alarm is triggered; if a fault is detected, the fault edge is identified, and a trip command is sent to the relay protecting the fault edge. This invention relies on an interference counter to detect continuous interference in the network and identify fault edges. Through spatiotemporal analysis of voltage amplitude and frequency data, faults are distinguished from grid disconnection events, making the detection mechanism more reliable.

Description

Technical Field

[0001] This invention relates to an adaptive protection method, device, storage medium, and computing equipment for intelligent distribution networks based on synchronized phasor data, belonging to the field of distribution protection technology. Background Technology

[0002] Modern distribution networks have a large number of distributed generation (DG) units, which are, in a sense, highly integrated. Centralized fault detectors use voltage phasor and frequency data to identify and isolate faults within a finite time, providing reliable network protection and improved situational awareness for smart distribution networks.

[0003] With the high penetration of distributed generation (DG) systems, distribution networks face several challenges in controlling and preventing unpredictable faults. The presence of multiple DG systems during a fault can lead to serious problems such as short-circuit current variability, local relay failure during fault isolation, and subsequent islanding issues. If the network topology changes over time, such as with the connection / disconnection of DG systems and loads, conventional solutions may fail to clear the fault within the critical isolation period. In such cases, post-fault voltage / frequency stability cannot be achieved. Summary of the Invention

[0004] The purpose of this invention is to provide an intelligent distribution network adaptive protection method, device, storage medium, and computing equipment based on synchronous phasor data, which can automatically distinguish between islanding and faults based on the measured values ​​and provide the correct protection scheme.

[0005] To achieve the above objectives, the present invention employs the following technical solution:

[0006] In a first aspect, the present invention provides an adaptive protection method for intelligent distribution networks based on synchronized phasor data, comprising:

[0007] Collect synchronization phasor data frames;

[0008] The average amplitude deviation and frequency deviation are calculated based on the current synchronization phasor data frame, and the interference counter is calculated based on the average amplitude deviation and frequency deviation as follows:

[0009] ;

[0010] ;

[0011] ;

[0012] in, , and For the defined current time Three interference counters, , and Indicates the previous moment Interference counter, It is the amplitude deviation threshold for centralized fault detection. and These are the amplitude deviation and frequency deviation thresholds for islanded verification, respectively. For the current moment The average amplitude deviation, For the current moment frequency deviation, It is a symbolic function;

[0013] Based on the interference counter, islanding and faults are identified; if it is an island, an islanding alarm is triggered; if it is a fault, the fault edge is identified, and a trip command is sent to the relay protecting the fault edge.

[0014] Preferably, the , and The initial value is 0.

[0015] Preferably, the calculation of the average amplitude deviation and frequency deviation is as follows:

[0016] ;

[0017] ;

[0018] in, Indicates the observation node At the present moment Phase at voltage amplitude, Indicates the observation node phase The nominal voltage amplitude, Indicates the current moment From the observation node Frequency of reports This is the nominal system frequency, and the observation node represents the synchronous phasor measurement unit. This indicates the number of synchronous phasor measurement units.

[0019] Preferably, identifying islands and faults based on the interference counter includes:

[0020] If the conditions of continuous overvoltage disturbance or continuous frequency disturbance are met, then it is an island;

[0021] The sustained overvoltage disturbance is represented as follows: ;

[0022] The sustained frequency perturbation is represented as: ;

[0023] in, The number of frames transmitted per second for the synchronous phasor measurement unit. This indicates a detection delay. Indicates the tolerance time for the isolated island. Indicates the island failure time / fault clearing time. Indicates the current time Frequency deviation range, The threshold representing the frequency deviation range in islanded mode.

[0024] Preferably, identifying islands and faults based on the interference counter includes:

[0025] If it is identified as a single-phase fault, two-phase fault, or three-phase fault, then it is a fault.

[0026] The single-phase fault is represented as follows: ;

[0027] The two-phase fault is represented as follows: ;

[0028] The three-phase fault is represented as follows: .

[0029] Preferably, the detection delay is expressed as:

[0030] ,

[0031] in, and These represent the processing times of the synchronous phasor measurement unit and the phasor data concentrator, respectively. This indicates the delay in the arrival of synchronization phasor data introduced by the data communication link.

[0032] Preferably, the frequency deviation range is expressed as:

[0033] ;

[0034] in, This represents the set of observation nodes.

[0035] Preferably, fault edges are identified in the following manner:

[0036] ;

[0037] ;

[0038] in, Indicates the edge of a fault. The detection index indicates the moment when the fault was detected. Indicates at time phase Zhong Cong Flow to The normalized current magnitude, and These represent the actual measured current and the expected current, respectively.

[0039] Secondly, the present invention provides an intelligent distribution network adaptive protection device based on synchronized phasor data, used to implement the above-mentioned intelligent distribution network adaptive protection method based on synchronized phasor data, the device comprising:

[0040] The data collection module is used to collect synchronization phasor data frames;

[0041] The calculation module is used to calculate the average amplitude deviation and frequency deviation based on the synchronization phasor data frame at the current moment, and to calculate the interference counter based on the average amplitude deviation and frequency deviation as follows:

[0042] ;

[0043] ;

[0044] ;

[0045] in, , and For the defined current time Three interference counters, , and Indicates the previous moment Interference counter, It is the amplitude deviation threshold for centralized fault detection. and These are the amplitude deviation and frequency deviation thresholds for islanded verification, respectively. For the current moment The average amplitude deviation, For the current moment frequency deviation, It is a symbolic function;

[0046] The identification and protection module is used to identify islands and faults based on the interference counter; if it is an island, it will issue an island alarm; if it is a fault, it will identify the fault edge and send a trip command to the relay protecting the fault edge.

[0047] Preferably, the identification and protection module is specifically used for,

[0048] Identify islands and faults as follows:

[0049] If the conditions of continuous overvoltage disturbance or continuous frequency disturbance are met, then it is an island;

[0050] The sustained overvoltage disturbance is represented as follows: ;

[0051] The sustained frequency perturbation is represented as: ;

[0052] in, The number of frames transmitted per second for the synchronous phasor measurement unit. This indicates a detection delay. Indicates the tolerance time for the isolated island. Indicates the island failure time / fault clearing time. Indicates the current time Frequency deviation range, The threshold representing the frequency deviation range in islanded mode;

[0053] If it is identified as a single-phase fault, two-phase fault, or three-phase fault, then it is a fault.

[0054] The single-phase fault is represented as follows: ;

[0055] The two-phase fault is represented as follows: ;

[0056] The three-phase fault is represented as follows: .

[0057] Thirdly, the present invention provides a computer-readable storage medium for storing one or more programs, said one or more programs including instructions that, when executed by a computing device, cause the computing device to perform any of the methods described above.

[0058] Fourthly, the present invention provides a computing device comprising one or more processors, a memory, and one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the one or more processors, the one or more programs comprising instructions for performing any of the methods described above.

[0059] The beneficial effects of this invention are as follows:

[0060] This invention provides an adaptive protection method for distribution networks based on synchronous phasor data. By analyzing the spatiotemporal data of voltage amplitude and frequency, it distinguishes faults from grid disconnection events, making the detection mechanism more reliable and ensuring that the detection time of line faults meets the stability time requirements under fault-triggered islanding conditions. Attached Figure Description

[0061] Figure 1 A flowchart of an adaptive protection method for intelligent distribution networks based on synchronized phasor data is provided for an embodiment of the present invention. Detailed Implementation

[0062] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the embodiments and accompanying drawings. Here, the illustrative embodiments and descriptions of this invention are used to explain the invention, but are not intended to limit the invention.

[0063] It should be emphasized here that the step markers mentioned below are not a limitation on the order of the steps, but should be understood as meaning that the steps can be executed in the order mentioned in the embodiments, or in a different order than in the embodiments, or several steps can be executed simultaneously.

[0064] Secondly, the term "an embodiment" or "embodiment" as used in this invention refers to a specific feature, structure, or characteristic that can be included in at least one implementation of this invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that excludes other embodiments.

[0065] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings. The following examples are for illustrative purposes only and are not intended to limit the scope of the invention.

[0066] Example 1

[0067] A synchronized phasor network consists of synchronized phasor measurement units (PMUs), phasor data concentrators (PDCs), and data communication links. Distributed PMUs extract phasors, system frequency, and rate of change of frequency in a synchronized manner. Local PDCs collect synchronized phasor data frames and construct synchronized phasor datasets. If necessary, they can also archive, process, and send the datasets to other PDCs. In recent years, high-precision miniature PMUs have been developed, which facilitate the acquisition of phasor data from distribution networks at very low cost.

[0068] Assuming L PMUs are used to monitor a distribution network, and each PMU transmits data per second... Frames. During normal operation, the PMU network can use an undirected graph. It is represented that the set of vertices is The edge set is Each vertex Associated with PMU, each edge point This represents a pair of consecutive observation nodes. By convention, a vertex... Associated with the main PCC. Without loss of generality, we assume that each pair of adjacent PMUs corresponds to two adjacent buses in the network.

[0069] When protection actions are performed on the feeder, the network becomes a two-way circuit. The portion of the network that remains connected to the public grid continues to operate in grid-connected mode, as shown in the sub-diagram. This indicates that isolated components that can continue to operate in islanded mode are represented by subgraphs. Indicate. Let. This represents the edge that has failed. When the endpoint of the edge moves to the set... and At that time, it can be achieved by eliminating the edges. Find two subgraphs and The same concept can be applied to DGs connected to networks, i.e. and These represent DGs in a connected subnet and an isolated subnet, respectively.

[0070] Let variables and Representing observation nodes At the point of time Phase at The voltage amplitude and phase angle. Furthermore, let... Indicates a point in time From the observation node The frequency of the report. The secondary controller receives data from the phasor data concentrator (PDC) and calculates the average amplitude and frequency deviation:

[0071] (1)

[0072] (2)

[0073] in Indicates the observation node phase The nominal voltage amplitude, This is the nominal system frequency. Since all elements in the synchronized phasor dataset have the same measurement time, the secondary controller can calculate the instantaneous range of the frequency data as:

[0074] (3)

[0075] This invention employs a secondary controller that receives data sets from the local PDC and protection messages from relays deployed within the network. The secondary controller adapts to potential faults by communicating with the relays and local controller of the DG system. Simultaneously, the secondary controller processes the synchronized phasor data sets in real time to identify faults and coordinate control commands with impending protection actions.

[0076] To enable secondary controllers to distinguish between faults and disconnection from the public grid, the timing parameters of synchronizing phasor data must be considered. System frequency is a well-known global parameter of the distribution network. However, due to the parameter estimator used by the PMU, coupling can occur between phasor magnitude / angle and frequency data during transients and faults. In this case, if a line fault interferes with the phasor data, the frequency data will also deviate. Furthermore, frequency data reported by different PMUs can show different values. Strictly speaking, the secondary controller observes not only deviations in amplitude data but also inconsistencies in frequency. Decisions based on instantaneous values ​​of average frequency deviations can lead to false islanding alarms. Therefore, preventing false islanding alarms is crucial when line faults occur in the network.

[0077] Assume at time... A permanent line fault will generate a series of interference data, which will arrive at the secondary controller with a certain time delay. Assuming no loss in the data communication link (packet loss), the first dataset carrying the disturbance information will arrive at a time less than or equal to... Time delay to reach the secondary controller:

[0078] (4)

[0079] in and These represent the processing times of the synchronous phasor measurement unit (PMU) and the phasor data concentrator (PDC), respectively. This represents the arrival delay of synchronization phasor data introduced by the data communication link, and is assumed to be constant during the detection interval. The secondary controller can use the timestamp provided in the synchronization phasor packet to determine... The value of This is the maximum time required for the first dataset carrying interference information to reach the secondary controller without data packet loss. Therefore, assuming... This is known to be reasonable. It should be noted that the fault could occur at any time between two consecutive reporting moments; therefore, This represents the maximum delay in reporting interference data. In this case, equation (4) expresses the worst-case scenario of detection delay from the perspective of centralized protection applications.

[0080] In fact, local protection devices may fail to clear faults in a timely manner, especially when the high penetration of the DG system affects the short-circuit current. In this case, a centralized protection algorithm is needed to detect faults across the entire network. Example 1 presents a centralized fault detection process based on a synchronization phasor dataset, such as... Figure 1 As shown, the details are as follows:

[0081] When k=0:

[0082] initialization: .

[0083] When k>0:

[0084] 1) Calculate the average amplitude deviation according to formula (1) and formula (2). and frequency deviation And update the interference counter:

[0085] (5)

[0086] (6)

[0087] (7)

[0088] In the formula, , , It is an interference counter, used to detect persistent interference in a network and identify fault edges. <0 is the amplitude deviation threshold for centralized fault detection. >0 represents the magnitude of islanded verification. >0 is the frequency deviation threshold. It is a symbolic function.

[0089] 2) Differentiate between isolated events and malfunctions:

[0090] If either condition (CI) or (C-II) is met, proceed to islanding alarm; otherwise, proceed to step 3.

[0091] Condition (CI): Sustained overvoltage disturbance:

[0092] ;

[0093] Condition (C-II): Continuous frequency perturbation:

[0094] ;

[0095] In the formula, Islanding tolerance time refers to the time during which a power system can continue to operate stably under islanding mode. This refers to the islanding failure time / fault clearing time, which is the maximum allowable time for the system to maintain stable operation after being disconnected in islanding mode. yes The deviation range of the frequency parameter at any given time. It is the threshold for the frequency deviation range in islanded mode.

[0096] 3) Fault detection:

[0097] When one of the conditions (C-III), (C-IV), and (CV) is met, the detection index is set to This indicates and records the detection time point of the fault or islanding event, and proceeds to step 4). Otherwise, go to step 1), and the time point becomes... ,

[0098] Condition (C-III): Single-phase fault:

[0099] ;

[0100] Condition (C-IV): Two-phase fault:

[0101] ;

[0102] Condition (CV): Three-phase fault:

[0103] .

[0104] 4) Identify fault edges:

[0105] Identify fault edges based on the value of standardized fault current:

[0106] (8)

[0107] in The calculation can be referenced from formula (9).

[0108] 5) Trigger auxiliary protection and control:

[0109] Towards the edge of protection The relay sends a trip command.

[0110] The algorithm proposed in this embodiment relies on an interference counter, i.e. , and This is used to detect persistent interference in the network and identify fault edges. In this algorithm, The threshold value representing the frequency deviation range in islanded mode is a setting value. Indicates a point in time phase Zhong Cong Flow to The normalized current magnitude. Islanding is a predetermined parameter that defines... This represents the upper bound of legitimate isolated events. (By...) The value can be verified by comparing it with the persistence of island bands and the consistent perturbation in the frequency data. The value is calculated in real time based on information received from the local relay and the nominal current magnitude of each edge:

[0111] (9)

[0112] in and These represent the actual measured current and the expected current, respectively. Assume... The value is known a priori by the secondary controller.

[0113] In the algorithm, and These represent the fault tolerance time and (possible) island fault tolerance time, respectively. It is the amplitude deviation threshold for centralized fault detection, while and These are the amplitude deviation and frequency deviation thresholds for islanding verification, respectively. In the hierarchical control framework, the secondary controller can monitor the operation of the DG system in real time. This allows the secondary controller to adaptively determine the fault tolerance time based on load and DG system information. In this mechanism, the algorithm ensures reliable fault detection, meeting the stability time requirements under fault-triggered islanding conditions.

[0114] Since the location and capacity of the DG system within the network are known, offline simulation of the isolated system can be used to obtain [the necessary parameters]. and threshold and An appropriate value. Transients caused by switching actions, lightning, etc., may interfere with the frequency data of some observation nodes. However, equations (1) and (2) counteract the effects of such transients by balancing the perturbations on all observation nodes. Therefore, only when the duration of the transient across the network is longer than the island fault tolerance time. The algorithm will only trigger the island verification process at that time.

[0115] A line fault with very low resistance will cause a voltage drop, which can be sensed by all PMUs deployed throughout the network. Typically, the magnitude of the undervoltage may vary between observation nodes. However, the voltage drop manifests as an average amplitude deviation. Therefore, if all DG systems are operating at their rated power, the undervoltage threshold can be determined based on the spatial average of the voltage drop. .

[0116] Step 2 of the algorithm performs islanding verification under possible overvoltage or frequency drift conditions. Condition CI verifies whether a sustained overvoltage disturbance is observed in at least one phase while other phases do not exhibit a sustained undervoltage deviation. Condition C-II studies the spatiotemporal characteristics of the frequency data across the entire network domain. Immediately after an islanding event, frequency data from all observed nodes on the network tend to deviate from the nominal frequency. This means that if an islanding event occurs, the range of frequency data... Confined to a small frequency band (island band), the average deviation exceeds the frequency disturbance threshold. Furthermore, depending on the estimation method used by the PMU, some faults may cause distortion in the reported frequency data. When the frequency perturbation exceeds the islanded frequency band, the frequency disturbance is inconsistent. In this case, step 3) of the algorithm verifies the occurrence of the fault.

[0117] In step 3) of the algorithm, a line fault is detected when at least one phase exhibits a persistent undervoltage disturbance while other phases exhibit overvoltage. In step 4), the secondary controller first sends signals to the edge... The associated local relay sends a request command to obtain the magnitude of the fault current (measured immediately after the fault). Based on the received information, the fault edge is identified by finding the maximum sum of the normalized current magnitudes on the fault phase, as shown in Equation (8). By using the algorithm, the centralized detector can distinguish between possible islanded events and faults, and ensure timely detection of line faults.

[0118] It should be noted that local protection systems typically require several cycles to detect and isolate line faults. If the local protection detects a fault in a timely manner, the secondary controller receives an Object-Oriented Substation Event (GOOSE) message from the local relay. Once the fault edge is detected, it will trigger... Auxiliary control.

[0119] Example 2

[0120] Based on the same inventive concept as Embodiment 1 above, Embodiment 2 provides a distribution network adaptive protection device based on synchronized phasor data, the device comprising:

[0121] The data collection module is used to collect synchronization phasor data frames;

[0122] The calculation module is used to calculate the average amplitude deviation and frequency deviation based on the synchronization phasor data frame at the current moment, and to calculate the interference counter based on the average amplitude deviation and frequency deviation as follows:

[0123] ;

[0124] ;

[0125] ;

[0126] in, , and For the defined current time Three interference counters, , and Indicates the previous moment Interference counter, It is the amplitude deviation threshold for centralized fault detection. and These are the amplitude deviation and frequency deviation thresholds for islanded verification, respectively. For the current moment The average amplitude deviation, For the current moment frequency deviation, It is a symbolic function;

[0127] The identification and protection module is used to identify islands and faults based on the interference counter; if it is an island, it will issue an island alarm; if it is a fault, it will identify the fault edge and send a trip command to the relay protecting the fault edge.

[0128] In one embodiment, the identification and protection module is specifically used for,

[0129] Identify islands and faults as follows:

[0130] If the conditions of continuous overvoltage disturbance or continuous frequency disturbance are met, then it is an island;

[0131] The sustained overvoltage disturbance is represented as follows: ;

[0132] The sustained frequency perturbation is represented as: ;

[0133] in, The number of frames transmitted per second for the synchronous phasor measurement unit. This indicates a detection delay. Indicates the tolerance time for the isolated island. Indicates the island failure time / fault clearing time. Indicates the current time Frequency deviation range, The threshold representing the frequency deviation range in islanded mode;

[0134] If it is identified as a single-phase fault, two-phase fault, or three-phase fault, then it is a fault.

[0135] The single-phase fault is represented as follows: ;

[0136] The two-phase fault is represented as follows: ;

[0137] The three-phase fault is represented as follows: .

[0138] The rest are the same as in Example 1.

[0139] It should be noted that this device embodiment corresponds to the above method embodiment. The implementation methods of the above method embodiments are all applicable to this device embodiment and can achieve the same or similar technical effects, so they will not be described in detail here.

[0140] Example 3

[0141] Based on the same inventive concept as Embodiment 1, Embodiment 3 of the present invention provides a computer-readable storage medium for storing one or more programs, the one or more programs including instructions that, when executed by a computing device, cause the computing device to perform any of the methods described in Embodiment 1 above.

[0142] Example 4

[0143] Based on the same inventive concept as Embodiment 1, Embodiment 4 of the present invention provides one or more processors, a memory, and one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the one or more processors, and the one or more programs include instructions for performing any of the methods in Embodiment 1 above.

[0144] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0145] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0146] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0147] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0148] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A distribution network adaptive protection method based on synchronized phasor data, characterized in that, include: Collect synchronization phasor data frames; The average amplitude deviation and frequency deviation are calculated based on the current synchronization phasor data frame, as follows: ； ； in, For the current moment The average amplitude deviation For the current moment frequency deviation, Indicates the observation node At the present moment Phase at voltage amplitude, Indicates the observation node Phase The nominal voltage amplitude, Indicates the current moment From the observation node Frequency of reports This is the nominal system frequency, and the observation node represents the synchronous phasor measurement unit. Indicates the number of synchronous phasor measurement units; The interference counter is calculated based on the average amplitude deviation and frequency deviation as follows: ； ； ； in, , and For the defined current time Three interference counters, , and Indicates the previous moment Interference counter, It is the amplitude deviation threshold for centralized fault detection. and These are the amplitude deviation and frequency deviation thresholds for islanded verification, respectively. It is a symbolic function; Based on the interference counter, islanding and fault identification includes: If the conditions of continuous overvoltage disturbance or continuous frequency disturbance are met, then it is an island; The sustained overvoltage disturbance is represented as follows: ; The sustained frequency perturbation is represented as: ; in, The number of frames transmitted per second for the synchronous phasor measurement unit. This indicates a detection delay. Indicates the tolerance time for the isolated island. Indicates the island failure time / fault clearing time. Indicates the current time Frequency deviation range, The threshold representing the frequency deviation range in islanded mode; If it is identified as a single-phase fault, two-phase fault, or three-phase fault, then it is a fault. The single-phase fault is represented as follows: ; The two-phase fault is represented as follows: ; The three-phase fault is represented as follows: ; If the system is isolated, an islanding alarm will be triggered; if the system is faulty, the fault edge will be identified, and a trip command will be sent to the relay protecting the fault edge.

2. The adaptive protection method for distribution networks based on synchronized phasor data according to claim 1, characterized in that, The , and The initial value is 0.

3. The adaptive protection method for distribution networks based on synchronized phasor data according to claim 1, characterized in that, The detection delay is expressed as: ， in, and These represent the processing times of the synchronous phasor measurement unit and the phasor data concentrator, respectively. This indicates the delay in the arrival of synchronization phasor data introduced by the data communication link.

4. The adaptive protection method for distribution networks based on synchronized phasor data according to claim 1, characterized in that, The frequency deviation range is expressed as follows: ； in, This represents the set of observation nodes.

5. The adaptive protection method for distribution networks based on synchronized phasor data according to claim 1, characterized in that, Identify fault edges in the following way: ； ； in, Indicates the edge of a fault. The detection index indicates the moment when the fault was detected. Indicates at time Phase Zhong Cong Flow to The normalized current magnitude, and These represent the actual measured current and the expected current, respectively.

6. A distribution network adaptive protection device based on synchronized phasor data, characterized in that, The apparatus for implementing the distribution network adaptive protection method based on synchronous phasor data as described in any one of claims 1 to 5, the apparatus comprising: The data collection module is used to collect synchronization phasor data frames; The calculation module is used to calculate the average amplitude deviation and frequency deviation based on the synchronization phasor data frame at the current moment, and to calculate the interference counter based on the average amplitude deviation and frequency deviation as follows: ； ； ； in, , and For the defined current time Three interference counters, , and Indicates the previous moment Interference counter, It is the amplitude deviation threshold for centralized fault detection. and These are the amplitude deviation and frequency deviation thresholds for islanded verification, respectively. For the current moment The average amplitude deviation For the current moment frequency deviation, It is a symbolic function; The identification and protection module is used to identify islands and faults based on the interference counter; if it is an island, it will issue an island alarm; if it is a fault, it will identify the fault edge and send a trip command to the relay protecting the fault edge.

7. A distribution network adaptive protection device based on synchronous phasor data according to claim 6, characterized in that, The identification and protection module is specifically used for, Identify islands and faults as follows: If the conditions of continuous overvoltage disturbance or continuous frequency disturbance are met, then it is an island; The sustained overvoltage disturbance is represented as follows: ; The sustained frequency perturbation is represented as: ; in, The number of frames transmitted per second for the synchronous phasor measurement unit. This indicates a detection delay. Indicates the tolerance time for the isolated island. Indicates the island failure time / fault clearing time. Indicates the current time Frequency deviation range, The threshold representing the frequency deviation range in islanded mode; If it is identified as a single-phase fault, two-phase fault, or three-phase fault, then it is a fault. The single-phase fault is represented as follows: ; The two-phase fault is represented as follows: ; The three-phase fault is represented as follows: .

8. A computer-readable storage medium for storing one or more programs, characterized in that, The one or more programs include instructions that, when executed by a computing device, cause the computing device to perform any of the methods according to claims 1 to 5.

9. A computing device, characterized in that, include, One or more processors, a memory, and one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the one or more processors, the one or more programs including instructions for performing any of the methods according to claims 1 to 5.

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