Power supply relay protection method, control equipment, power supply device and medium

Abstract

The invention relates to a power supply relay protection method, a control device, a power supply device and a medium, and the power supply relay protection method comprises the following steps: comparing new data collected by each monitoring point of a whole grid-connected system with standard data in a database to find the abnormality of the new data, and analyzing a fault area according to the abnormality. According to the method, firstly, the model is established according to the monitoring point position, the upstream or downstream area of the relative monitoring point is quickly judged according to the operation data, and even the accurate position is distinguished by setting the threshold value, and meanwhile, reporting and notification of similar operation and maintenance point personnel are carried out, so that the problems of low troubleshooting efficiency and low troubleshooting cost are avoided. And meanwhile, electrical quantity monitoring and uploading are carried out on regional current and voltage monitoring equipment of a fault monitoring point, and specific data information is transmitted to the system for analysis and specific execution after secondary checking is carried out on frequency and power of a power grid in a local area.

Description

Technical Field

[0001] The present invention relates to the field of distributed photovoltaic power supply relay protection, and in particular to a power supply relay protection method, a control device, a power supply device and a medium. Background Art

[0002] The access of distributed generation (DG) has changed the structure of traditional distribution network and brought severe challenges to traditional relay protection. This situation makes power supply enterprises analyze the impact of distributed generation on distribution network relay protection in detail according to the characteristics and structure of current distributed generation and their own distribution network conditions, so as to promote the safe and reliable operation of enterprise power grid and improve the economic benefits of power enterprises. Distributed generation mainly includes solar power generation, wind power generation, micro gas turbines, fuel cells and batteries. These power sources usually have small installed capacity and can be close to power users. Therefore, they can directly supply power to power loads or export power to distribution networks as needed;

[0003] Due to the access of distributed photovoltaics, the distribution network has changed from a traditional single-power radial network to a multi-power network with access to many small and medium-sized power sources, which will affect the short-circuit current distribution and the coordination of relay protection in the traditional distribution network. The existing protection configuration and automatic reclosing device must be adjusted accordingly. Otherwise, due to the access of distributed photovoltaics, the selectivity and sensitivity of the existing relay protection will inevitably be affected, which will have a great impact on the safe and stable operation of the distribution network and its electrical equipment.

[0004] However, the following problems were found in the implementation of relevant technologies: in the prior art, the maintenance of power supply failures is still mainly based on troubleshooting, but the entire grid-connected system covers a large area, which may result in the failure to maintain or repair the fault location in the first time when a problem occurs, resulting in a slow maintenance process and possible unnecessary losses. In view of this, a distributed photovoltaic power supply relay protection method based on power monitoring is provided to overcome the above-mentioned defects. Summary of the invention

[0005] The purpose of the present invention is to solve the shortcomings of the prior art and to propose a power supply relay protection method, a control device, a power supply device and a medium.

[0006] In order to achieve the above object, the present invention proposes a power supply relay protection method, comprising the following steps:

[0007] Compare the new data collected from each monitoring point of the entire power grid-connected system with the standard data in the database to find out the anomalies of the new data and analyze the fault area based on the anomalies;

[0008] After the fault area is determined, the electrical quantity data of the relevant equipment in the fault area is monitored and extracted, and the extracted electrical quantity is compared with the preset threshold value to find the abnormality of the electrical quantity, and the fault point is determined according to the abnormal electrical quantity;

[0009] The power monitoring device collects power data of the fault point and compares the collected power data with the preset power threshold;

[0010] After analyzing the circuit operation characteristics, the appropriate protection method is selected and executed, and the protection work is started.

[0011] Optionally, the new data collected from each monitoring point of the entire grid-connected system is compared with the standard data in the database to find abnormalities in the new data, and the fault area is analyzed according to the abnormalities, and the uploading and updating and the dispatching of maintenance personnel for the fault area include the following steps:

[0012] Monitoring point division and setting; Monitoring point division and setting; Monitor each node through monitoring equipment, so as to divide the area in time when problems occur

[0013] Conduct secondary investigation on the fault point; Conduct secondary investigation on the fault point; Determine that the fault point is located upstream or downstream of the monitoring point to further narrow the investigation scope;

[0014] Upload and backup operation and maintenance information; upload the location of the fault point data to facilitate operation and maintenance personnel to collect and carry out the next step of work;

[0015] Selection of maintenance personnel: Select the nearest maintenance personnel or maintenance point according to the location of the fault point to improve the timeliness of troubleshooting and repair;

[0016] Fault information update: timely update for different fault points to avoid unnecessary impact.

[0017] Optionally, the monitoring point division setting includes: the monitoring points are set as K1, K2... and so on, and are used to establish a distributed photovoltaic grid-connected model simulation.

[0018] Optionally, after determining the fault area, the extracted electrical quantity is compared with a preset threshold, and the frequency of the local power grid and the work done by the equipment are monitored at the same time, so as to improve the accuracy of the fault point determination, including the following steps:

[0019] Current monitoring;

[0020] Voltage monitoring;

[0021] Local power grid frequency monitoring;

[0022] Equipment work monitoring.

[0023] Optionally, local power grid frequency monitoring includes: implementing frequency protection through relay protection devices, and recording and detecting rated values ​​of power grid frequency stability.

[0024] Optionally, the steps of transmitting the obtained data, determining the fault type, determining the protection action, then executing the protection action, and uploading and feeding back the data include the following steps:

[0025] Data collection and transmission;

[0026] Protection action decision;

[0027] Action execution and feedback.

[0028] Optionally, comparing the current terminal, voltage, frequency and current direction of the line and performing protection comprises the following steps:

[0029] Current terminal protection function;

[0030] Voltage protection function;

[0031] Relay protection device realizes frequency protection;

[0032] Current direction protection.

[0033] According to a second aspect of an embodiment of the present disclosure, there is provided a control device for power supply relay protection, comprising:

[0034] The first comparison module compares the new data collected from each monitoring point of the entire grid-connected system with the standard data in the database. If the data is abnormal, it is a fault area, otherwise it is a normal area;

[0035] The first acquisition and extraction module, after determining the fault area, monitors and extracts the data of the electrical quantities of the relevant equipment in the fault area;

[0036] The second comparison module compares the extracted electrical quantity with a preset threshold value to find out the abnormality of the electrical quantity and determine the fault point according to the abnormal electrical quantity;

[0037] The second collection and extraction module, the power monitoring device collects the power data of the fault point, and compares the collected power data with the preset power threshold to determine the fault type;

[0038] The execution module selects and executes the appropriate protection mode and starts the protection work after analyzing the circuit operation characteristics.

[0039] According to a third aspect of an embodiment of the present disclosure, there is provided a power supply device, including:

[0040] processor;

[0041] a memory for storing processor-executable instructions;

[0042] The processor is configured to execute the executable instructions to implement the steps of the method in any one of the above-mentioned embodiments.

[0043] According to a fourth aspect of an embodiment of the present disclosure, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the steps of the method described in any one of the above embodiments are implemented.

[0044] The present invention has the following beneficial effects:

[0045] A power supply relay protection method designed by the present invention first establishes a model according to the monitoring point position, quickly determines the upstream or downstream area relative to the monitoring point according to the calculation data, and even distinguishes the accurate position by setting a threshold value, and reports and notifies the personnel of the nearby operation and maintenance points at the same time to avoid slow troubleshooting efficiency. At the same time, the regional current and voltage monitoring equipment of the fault monitoring point is monitored and uploaded for electrical quantities, and after a secondary check of the frequency and power of the local power grid is carried out, the specific data information is transmitted to the system for analysis and specific execution.

[0046] The present invention designs a power supply relay protection method, in which a power monitoring device collects data and transmits the data to a relay protection device via optical fiber or wireless communication, requiring reliable communication and strong real-time performance. The power data is analyzed according to the relay protection device, compared with a preset threshold, the fault type is judged, the protection action is determined, and then the protection action is executed, and the action information is fed back to provide a basis for fault analysis and repair, playing a connecting role in the entire process.

[0047] The present invention designs a power supply relay protection method. When a line short circuit causes the current to increase instantaneously, the detected current value is compared with a preset overcurrent threshold. If the threshold is exceeded, the circuit is cut off in time to prevent the equipment from being damaged due to overload. When the current is undercurrent, a disconnection fault occurs in the circuit, which can also be detected by the undercurrent protection and an alarm is issued to prompt the staff to troubleshoot the fault (it does not cause damage to the equipment cables, etc., and the power supply cannot be cut off). When the grid voltage fluctuates, the protection device will respond quickly. When a transient overvoltage occurs in the grid, the relay protection device can compare the detected voltage with the set overvoltage protection value. If it exceeds the value, it will act to protect the insulation of the photovoltaic power supply and related equipment from being damaged. The undervoltage protection takes effect when the voltage is too low. , which may be caused by a grid fault or an inverter fault of the distributed photovoltaic power source itself. At this time, the protection device protects the equipment by cutting off the circuit or adjusting the working state of the inverter. Under normal circumstances, the grid frequency is stable near the rated value. When the frequency is abnormal, the frequency protection function takes effect to ensure the stable connection between the distributed photovoltaic power source and the grid and prevent impact on the grid frequency. For complex circuits where distributed photovoltaic power sources are connected to the grid, directional protection can distinguish the direction of the fault current. When the direction of the fault current does not match the set direction during normal operation, it indicates that there may be a reverse fault, such as reverse power backflow. The directional protection will accurately identify and take protective measures to ensure the normal transmission of electric energy and the safety of equipment.

[0048] A power supply relay protection method designed by the present invention calculates the power change rate in a short time after receiving power data. The difference between the power value at the current sampling moment and the power value at a previous moment is divided by the time interval between the two moments. If the power change rate exceeds a preset threshold, it is determined that a power mutation has occurred. Subsequently, feature analysis is performed based on the obtained data, such as the power fluctuation range during normal operation, the capacity of the photovoltaic power supply, the stability requirements of the power grid, etc., to analyze the problem and perform protection actions. For example, if the output power suddenly increases, it may be a short-circuit fault on the power grid side. The protection device will immediately cut off the connection between the photovoltaic power supply and the power grid to prevent the fault current from damaging the photovoltaic equipment. If the output power suddenly decreases, it may be an internal fault of the photovoltaic power supply, such as an inverter fault or damage to some photovoltaic components. The protection device will send an alarm signal and can take corresponding isolation measures according to the system design, such as isolating the faulty inverter or photovoltaic string from the system to avoid further expansion of the fault.

[0049] A power supply relay protection method designed by the present invention records or simulates each fault and protection behavior, and updates and records them in time, so as to establish a database. When a fault point occurs, comparison and analysis are performed based on the data, so as to quickly determine the fault point and protection form, and upload them in time, thereby further improving the timeliness of operation and maintenance under fault conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 It is a schematic diagram of the workflow of the present invention;

[0051] Figure 2 It is a schematic diagram of the workflow of step S1 of the present invention;

[0052] Figure 3 This is a distributed photovoltaic grid-connected model diagram of the present invention;

[0053] Figure 4 This is a distributed photovoltaic grid-connected data table model diagram of the present invention;

[0054] Figure 5 It is a schematic diagram of the workflow of step S2 of the present invention;

[0055] Figure 6 It is a schematic diagram of the workflow of step S3 of the present invention;

[0056] Figure 7 It is a schematic diagram of the workflow of step S4 of the present invention;

[0057] Figure 8 It is a schematic diagram of the workflow of step S5 of the present invention;

[0058] Fig. 9 It is a schematic diagram of the workflow of step S6 of the present invention. DETAILED DESCRIPTION

[0059] Reference Figure 1-9 The present invention provides a power relay protection method: comprising the following steps: S1, comparing the new data collected from each monitoring point of the entire grid-connected system with the standard data in the database to find the anomaly of the new data, and analyzing the fault area according to the anomaly; these monitoring points include the access point of the photovoltaic power source to the grid, the output point of the combiner box, and the input and output ends of the inverter and other key locations;

[0060] S2. After determining the fault area, monitor and extract the data of the electrical quantities of the relevant equipment in the fault area, compare the extracted electrical quantities with the preset threshold value to find the abnormality of the electrical quantities, and determine the fault point according to the abnormal electrical quantities; In addition to the protection function based on power monitoring, the relay protection device of the distributed photovoltaic power source also has multiple functions, such as current, voltage, etc.;

[0061] S3. The power monitoring device collects power data of the fault point and compares the collected power data with the preset power threshold to determine the fault type; after analyzing the collected data, it performs protection actions and promptly feeds back the action information, providing a basis for fault analysis and repair;

[0062] S4. Preliminarily perform protection work on the current, voltage and other aspects of the equipment body; disconnect the fault point range in time without affecting other branches and lines to form an island to avoid increasing the impact;

[0063] S5. After analyzing the circuit operation characteristics, select and execute the appropriate protection mode, and start the protection work to reduce the impact on other branches of the circuit and reduce losses; conduct in-depth analysis based on the collected data to determine the conflict of the fault point, analyze the cause of the fault and provide corresponding maintenance methods in time;

[0064] S6. Establish a database and set up a learning module, so that the fault mode record analysis can be uploaded to facilitate faster response to problems in the future; establish a cloud database, optimize the operation strategy, and quickly help staff accurately identify the fault point and cause.

[0065] As a further implementation plan of the above technical solution: compare the new data collected from each monitoring point of the entire grid-connected system with the standard data in the database to find the anomaly of the new data, and analyze the fault area according to the anomaly, and upload and update the fault area and dispatch maintenance personnel, including the following steps:

[0066] S101, monitoring point division and setting; monitoring each node through monitoring equipment, so as to divide the area in time when problems occur;

[0067] S102, conduct a secondary investigation of the fault point; determine that the fault point is located upstream or downstream of the monitoring point to further narrow the investigation scope;

[0068] S103, upload and backup the operation and maintenance information; by uploading the location of the fault point data, it is convenient for the operation and maintenance personnel to collect and carry out the next step;

[0069] S104. Maintenance personnel selection: Select the nearest maintenance personnel or maintenance point according to the location of the fault point to improve the timeliness of troubleshooting and maintenance;

[0070] S105. Fault information update: timely update for different fault points to avoid unnecessary impact.

[0071] by Figure 3 The distribution network model of is taken as an example for simulation research. It is assumed that the system base capacity SB is 100MVA, the voltage base UB is selected as 10.5kV, and the distributed photovoltaic access capacity is 5MVA. The power supply impedance is Zs·max=0.126jΩ in the minimum operation mode of the system, and Zs·min=0.09jΩ in the maximum operation mode. A short circuit fault occurs at 0.3s and lasts for 0.1s.

[0072] The simulated transmission line is an overhead line, and the impedance of each kilometer of the overhead line is Z = 0.27 + j 0.35Ω. The lengths of the protection lines L1 to L5 at locations 1 to 5 are 6km, 8km, 3km, 7km and 10km respectively. The model uses a constant impedance model to replace the terminal load: ZLD = 30 + j18.6Ω.

[0073] The total impedance of each line L1 to L5 can be calculated by the line impedance per kilometer and the line length, such as Figure 4 As shown;

[0074] At the same time, after the distributed power source is connected to the distribution network, the short-circuit current on the system side is reduced. Because the distributed power source is connected to the distribution network, it helps to increase the voltage at the access point. When the fault occurs upstream of the distributed power source, the distributed power source on the same feeder injects the corresponding short-circuit current into the bus between it and the fault point. When the fault occurs downstream of the distributed power source, the short-circuit current injected by the upstream bus on the same feeder decreases, while the short-circuit current injected by the downstream bus increases. In this way, the fault point and regional scope can be determined, and reported for real-time update at the same time. According to the regional scope of the fault point, the nearby maintenance point or maintenance personnel can be notified to perform rapid maintenance, thereby improving the timeliness of maintenance.

[0075] As a further implementation plan of the above technical solution: S101, monitoring points are divided and set, and the monitoring points are set as K1, K2... and so on, and are used to establish a distributed photovoltaic grid-connected model simulation; each monitoring point is set at a key node and encoded in the form of K1, K2, which can quickly identify the key node when a problem occurs, avoiding troublesome troubleshooting that affects maintenance efficiency.

[0076] As a further implementation scheme of the above technical scheme: after determining the fault area, the extracted electrical quantity is compared with the preset threshold value, and the frequency of the local power grid and the work done by the equipment are monitored at the same time, so as to improve the accuracy of the fault point determination, including the following steps:

[0077] S201, current monitoring: monitoring the line current of the equipment in the selected monitoring point area and comparing it with the normal threshold;

[0078] S202, voltage monitoring: monitoring the line voltage of the equipment in the selected monitoring point area and comparing it with the normal threshold;

[0079] S203, local power grid frequency monitoring: the power grid frequency of the equipment in the selected monitoring point area is monitored and compared with the normal threshold;

[0080] S204, equipment work monitoring: the power generated by the operation of the equipment in the selected monitoring point area is monitored and compared with a normal threshold.

[0081] After determining the upstream or downstream area of ​​the monitoring point, the current and voltage of the equipment in the circuit of the fault area are monitored, the detected current value is compared with the preset overcurrent threshold, and the detected voltage is compared with the set overvoltage protection value. At the same time, the frequency of the local power grid and the work done by the equipment are monitored to improve the accuracy of the fault point determination, so as to quickly identify the faulty equipment and issue early warning prompts, making it convenient for staff to quickly troubleshoot the fault.

[0082] As a further implementation plan for the above technical solution: S203, local power grid frequency monitoring; frequency protection is achieved through a relay protection device, and the rated value of the power grid frequency stability is recorded and detected; after determining the upstream area or downstream area of ​​the monitoring point, the local power grid frequency in this area can be monitored, and the frequency can be detected by the relay protection device and compared with the upper and lower limits of the set frequency. When the frequency is abnormal, such as when a power grid fault causes the frequency to exceed or fall below the normal threshold, the protection action will be triggered when it exceeds the range.

[0083] During the specific implementation, firstly, a model is established according to the monitoring point location, and the upstream or downstream area relative to the monitoring point is quickly determined based on the calculation data, and even the exact location is distinguished by setting a threshold. At the same time, it is reported and the personnel at the nearby operation and maintenance points are notified to avoid slow troubleshooting efficiency. At the same time, the regional current and voltage monitoring equipment of the fault monitoring point is monitored and uploaded for electrical quantities, and after a secondary check of the local power grid frequency and power, the specific data information is transmitted to S3 for analysis and specific execution.

[0084] As a further implementation plan of the above technical solution: the obtained data is transmitted, the fault type is determined, the protection action is determined, and then the protection action is executed, and the uploading and feedback are performed, including the following steps:

[0085] S301, data collection and transmission;

[0086] S302, protection action decision;

[0087] S303: Action execution and feedback.

[0088] During specific implementation, the power monitoring equipment collects data and transmits it to the relay protection device via optical fiber or wireless communication. The communication is required to be reliable and real-time. The power data is analyzed according to the relay protection device, compared with the preset threshold, the fault type is judged, the protection action is determined, and then the protection action is executed. The action information is fed back to provide a basis for fault analysis and repair, playing a connecting role in the whole process.

[0089] As a further implementation scheme of the above technical scheme: the comparison of the current end, voltage, frequency and current direction of the line and the execution of protection include the following steps:

[0090] S401, current terminal protection function;

[0091] S402, voltage protection function;

[0092] S403, relay protection device realizes frequency protection;

[0093] S404, current direction protection.

[0094] In specific implementation; when the line short circuit causes the current to increase instantly, the detected current value is compared with the preset overcurrent threshold. If it exceeds the threshold, the circuit will be cut off in time to prevent the equipment from being damaged by overload. When the current is undercurrent, the circuit will be disconnected, which can be detected by undercurrent protection and an alarm will be issued to prompt the staff to troubleshoot the fault (it does not cause damage to equipment cables, etc., and the power supply will not be cut off). When the grid voltage fluctuates, the protection device will respond quickly. When the grid has a transient overvoltage, the relay protection device can compare the detected voltage with the set overvoltage protection value. If it exceeds the value, it will act to protect the insulation of the photovoltaic power supply and related equipment from damage. The undervoltage protection takes effect when the voltage is too low, which may be caused by It is caused by grid failure or inverter failure of distributed photovoltaic power source itself. At this time, the protection device protects the equipment by cutting off the circuit or adjusting the working state of the inverter. Under normal circumstances, the grid frequency is stable near the rated value. When the frequency is abnormal, the frequency protection function takes effect to ensure the stable connection between the distributed photovoltaic power source and the grid and prevent impact on the grid frequency. For the complex circuit of distributed photovoltaic power source connected to the grid, the directional protection can distinguish the direction of the fault current. When the direction of the fault current does not match the set direction during normal operation, it indicates that there may be a reverse fault, such as reverse power backflow. The directional protection will accurately identify and take protective measures to ensure the normal transmission of electric energy and the safety of equipment.

[0095] As a further implementation scheme of the above technical scheme: after analyzing the circuit operation characteristics, selecting and executing a suitable protection mode, and starting the protection work include the following steps:

[0096] S501, circuit operation power characteristics analysis;

[0097] S502, analyzing and determining the cause of the fault in detail based on the data analysis;

[0098] S503. Select an appropriate protection method based on the cause.

[0099] In specific implementation, after receiving the power data, the power change rate will be calculated in a short time. The difference between the power value at the current sampling moment and the power value at a previous moment is divided by the time interval between the two moments. If the power change rate exceeds the preset threshold, it is determined that a power mutation has occurred. Subsequently, feature analysis is performed based on the obtained data, such as the power fluctuation range during normal operation, the capacity of the photovoltaic power source, the stability requirements of the power grid, etc. The problem is analyzed and protective actions are performed. For example, if the output power suddenly increases, it may be a short circuit fault on the grid side. The protection device will immediately cut off the connection between the photovoltaic power source and the grid to prevent the fault current from damaging the photovoltaic equipment. If the output power suddenly decreases, it may be an internal fault of the photovoltaic power source, such as an inverter fault or damage to some photovoltaic modules. The protection device will issue an alarm signal and can take corresponding isolation measures according to the system design, such as isolating the faulty inverter or photovoltaic module from the system to avoid further expansion of the fault.

[0100] As a further implementation scheme of the above technical scheme: after analyzing the circuit operation characteristics, selecting and executing a suitable protection mode, and starting the protection work include the following steps:

[0101] S601, database establishment;

[0102] S602, data analysis and accounting module;

[0103] S603, communication channel upload.

[0104] As a further implementation plan of the above technical solution: the communication channel medium of S603, communication channel upload, and communication channel upload is Zigbee, which has the characteristics of flexible deployment; the wireless form of Zigbee is adopted, which is convenient and flexible to deploy within the area, avoiding the trouble of pulling cables and large engineering workload

[0105] During the specific implementation, each fault and protection behavior is recorded or simulated, and updated and recorded in a timely manner to establish a database. When a fault point occurs, it is compared and analyzed based on the data to quickly determine the fault point and protection form, and upload it in a timely manner, thereby further improving the timeliness of operation and maintenance in the event of a fault.

[0106] According to a second aspect of an embodiment of the present disclosure, there is provided a control device for power supply relay protection, comprising:

[0107] The first comparison module compares the new data collected from each monitoring point of the entire grid-connected system with the standard data in the database. If the data is abnormal, it is a fault area, otherwise it is a normal area;

[0108] The first acquisition and extraction module, after determining the fault area, monitors and extracts the data of the electrical quantities of the relevant equipment in the fault area;

[0109] The second comparison module compares the extracted electrical quantity with a preset threshold value to find out the abnormality of the electrical quantity and determine the fault point according to the abnormal electrical quantity;

[0110] The second collection and extraction module, the power monitoring device collects the power data of the fault point, and compares the collected power data with the preset power threshold to determine the fault type;

[0111] The execution module selects and executes the appropriate protection mode and starts the protection work after analyzing the circuit operation characteristics.

[0112] According to a third aspect of an embodiment of the present disclosure, there is provided a power supply device, including:

[0113] processor;

[0114] a memory for storing processor-executable instructions;

[0115] The processor is configured to execute the executable instructions to implement the steps of the method in any one of the above-mentioned embodiments.

[0116] According to a fourth aspect of an embodiment of the present disclosure, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the steps of the method described in any one of the above embodiments are implemented.

[0117] Finally, it should be noted that the above are only preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A power supply relay protection method, characterized in that: The following steps are involved: Compare the new data collected from each monitoring point of the entire power grid-connected system with the standard data in the database to find out the anomalies of the new data and analyze the fault area based on the anomalies; After the fault area is determined, the electrical quantity data of the relevant equipment in the fault area is monitored and extracted, and the extracted electrical quantity is compared with the preset threshold value to find the abnormality of the electrical quantity, and the fault point is determined according to the abnormal electrical quantity; The power monitoring device collects power data of the fault point and compares the collected power data with the preset power threshold; After analyzing the circuit operation characteristics, the appropriate protection method is selected and executed, and the protection work is started.

2. The power supply relay protection method according to claim 1, characterized in that: The new data collected from each monitoring point of the entire grid-connected system is compared with the standard data in the database to find the anomaly of the new data, and the fault area is analyzed according to the anomaly, and the uploading and updating and the dispatching of maintenance personnel for the fault area include the following steps: Monitoring point division and setting; Monitoring point division and setting; Monitor each node through monitoring equipment, so as to divide the area in time when problems occur Conduct secondary investigation on the fault point; Conduct secondary investigation on the fault point; Determine that the fault point is located upstream or downstream of the monitoring point to further narrow the investigation scope; Upload and backup operation and maintenance information; upload the location of the fault point data to facilitate operation and maintenance personnel to collect and carry out the next step of work; Selection of maintenance personnel: Select the nearest maintenance personnel or maintenance point according to the location of the fault point to improve the timeliness of troubleshooting and repair; Fault information update: timely update for different fault points to avoid unnecessary impact.

3. The power supply relay protection method according to claim 2, characterized in that: The monitoring point division setting includes: setting the monitoring points to K1, K2, and so on, and using them for distributed photovoltaic grid-connected model simulation.

4. The power supply relay protection method according to claim 1, characterized in that: After the fault area is determined, the extracted electrical quantity is compared with a preset threshold value, and the frequency of the local power grid and the work done by the equipment are monitored at the same time. Improving the accuracy of fault point determination includes the following steps: Current monitoring; Voltage monitoring; Local power grid frequency monitoring; Equipment work monitoring.

5. The power supply relay protection method according to claim 4, characterized in that: Local power grid frequency monitoring includes: frequency protection through relay protection devices, and recording and detecting the rated value of power grid frequency stability.

6. The power supply relay protection method according to claim 1, characterized in that: After the fault area is determined, data of electrical quantities of related equipment in the fault area are extracted, and the extracted electrical quantities are compared with a preset threshold value to find abnormalities in the electrical quantities. Determining the fault point according to the abnormal electrical quantities includes the following steps: Data collection and transmission; Protection action decision; Action execution and feedback.

7. The power supply relay protection method according to claim 1, characterized in that: The comparison of the current terminal, voltage, frequency and current direction of the line and the execution of protection comprises the following steps: Current terminal protection function; Voltage protection function; Relay protection device realizes frequency protection; Current direction protection.

8. A control device for power supply relay protection, characterized in that: include: The first comparison module compares the new data collected from each monitoring point of the entire grid-connected system with the standard data in the database. If the data is abnormal, it is a fault area, otherwise it is a normal area; The first acquisition and extraction module, after determining the fault area, monitors and extracts the data of the electrical quantities of the relevant equipment in the fault area; The second comparison module compares the extracted electrical quantity with a preset threshold value to find out the abnormality of the electrical quantity and determine the fault point according to the abnormal electrical quantity; The second collection and extraction module, the power monitoring device collects the power data of the fault point, and compares the collected power data with the preset power threshold to determine the fault type; The execution module selects and executes the appropriate protection mode and starts the protection work after analyzing the circuit operation characteristics.

9. A power supply device, characterized in that: include: processor; a memory for storing processor-executable instructions; The processor is configured to execute the executable instructions to implement the steps of the method according to any one of claims 1 to 7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 7 are implemented.

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