Regional power grid electromagnetic looped network relay protection risk analysis method and related equipment

Abstract

The invention relates to the technical field of power systems, and provides a regional power grid electromagnetic looped network relay protection risk analysis method and related equipment, and the method comprises the steps: obtaining the basic data of a to-be-analyzed regional power grid, and guaranteeing that the analysis process can be carried out based on accurate and complete power grid information; a power grid model in an electromagnetic looped network operation mode is established based on basic data, and a platform is provided for subsequent calculation and analysis; bus values of all voltage levels before and after the operation of the electromagnetic looped network are calculated based on a power grid model, the influence of power grid structure change on bus voltage and current can be quantitatively evaluated, and key data support is provided for analyzing whether relay protection has risks or not; and finally, determining the parameter change of the power grid structure before and after the operation of the electromagnetic looped network according to the power grid model and the voltage level bus value, and analyzing whether the relay protection has a risk based on the parameter change, thereby comprehensively and accurately evaluating the risk condition of the relay protection when the regional power grid adopts the electromagnetic looped network operation mode.

Description

Technical Field

[0001] The present application relates to the technical field of power systems, and in particular to a method, device, computer equipment and storage medium for risk analysis of relay protection of a regional power grid electromagnetic ring network operating mode. Background Art

[0002] In order to improve the operational reliability of regional power grids, the "electromagnetic ring network" operation mode is usually adopted. The electromagnetic ring network is a ring-shaped power grid formed by transmission lines of different voltage levels through transformers or electromagnetic coupling, which can improve the flexibility and reliability of the power grid to a certain extent.

[0003] At present, before adopting the electromagnetic ring network operation mode, regional power grids usually conduct power grid flow analysis to assess whether the electromagnetic ring network operation will cause the risk of equipment load exceeding the power supply capacity. However, the lack of technical solutions for the relay protection risk analysis of the electromagnetic ring network operation mode of regional power grids may lead to insufficient assessment of the risks related to the relay protection of the electromagnetic ring network operation mode, and the decision to adopt the "electromagnetic ring network" operation mode is imperfect and unreasonable, which in turn brings unexpected grid operation risks. Summary of the invention

[0004] Based on this, a method, device, computer equipment and storage medium for risk analysis of relay protection of regional power grid electromagnetic ring network operation mode are proposed, aiming to solve the technical problem of insufficient risk assessment of relay protection in regional power grid electromagnetic ring network operation mode in the prior art.

[0005] The first aspect of the present application provides a method for risk analysis of electromagnetic ring network relay protection in a regional power grid, the method comprising:

[0006] Obtain basic data of the regional power grid to be analyzed;

[0007] Based on the basic data, a power grid model of the regional power grid to be analyzed under the electromagnetic ring network operation mode is established;

[0008] Based on the power grid model, bus values ​​of various voltage levels before and after the operation of the electromagnetic ring network are calculated;

[0009] Determine, according to the power grid model, a first parameter change of the power grid structure of the regional power grid to be analyzed before and after the operation of the electromagnetic ring network, and analyze whether there is a first risk in relay protection based on the first parameter change;

[0010] A second parameter change of the grid structure of the regional power grid to be analyzed before and after the operation of the electromagnetic ring network is determined according to the voltage level bus value, and based on the second parameter change, it is analyzed whether there is a second risk in the relay protection.

[0011] Optionally, the first parameter change includes one or more combinations of the following:

[0012] Changes in fault current, changes in auxiliary coefficient, uncertainty in fault point, changes in current protection branch coefficient, changes in fault current shunting of equipment within the loop, and changes in fault current of equipment outside the loop.

[0013] Optionally, the analyzing whether there is a first risk in relay protection based on the first parameter change includes one or more combinations of the following:

[0014] When the fault current of the electromagnetic ring network increases, analyze whether the transformer is at risk of being damaged due to the increase in fault current;

[0015] When the electromagnetic ring network auxiliary increase coefficient increases, the risk of transformer damage caused by insufficient remote backup sensitivity of 110kV line protection is analyzed;

[0016] When the fault point of the electromagnetic ring network is uncertain and the coordination of multi-level series supply and protection is difficult, analyze whether there is a risk of protection over-level misoperation and expanding power outage;

[0017] When the electromagnetic ring network causes the current protection branch coefficient to increase, analyze whether there is a risk of incomplete coordination between the 220kV main transformer backup protection and the 110kV outgoing line;

[0018] When the fault current of the equipment in the electromagnetic ring network is shunted, analyze whether there is a risk of long protection action time causing equipment damage;

[0019] When the value of the last segment of the zero sequence protection of the 110kV line is lower than the threshold, analyze whether there is a risk of false tripping and ring release caused by the electromagnetic ring network N-1;

[0020] When the fault current of the equipment outside the electromagnetic ring network increases, analyze whether there is a risk of protection tripping when the lower-level equipment fails;

[0021] When the electromagnetic ring network causes fault current shunting of equipment within the ring, analyze whether there is a risk that the remote backup sensitivity of the last section of the 110kV line zero sequence to the adjacent lower-level line does not meet the requirements.

[0022] Optionally, the second parameter change includes bus value impedance.

[0023] Optionally, analyzing whether there is a second risk in relay protection based on the change of the second parameter includes:

[0024] When the busbar impedance drop exceeds the preset drop threshold, analyze whether there is a risk of power outage area expansion and difficulty in fault finding and recovery due to protection over-trip malfunction when the lower-level equipment fails.

[0025] Optionally, the establishing of a power grid model under the electromagnetic ring network operation mode of the regional power grid to be analyzed based on the basic data includes:

[0026] Constructing a primary equipment model of the regional power grid to be analyzed according to a primary equipment basic parameter model;

[0027] Importing the protection setting value ledger into the primary equipment model;

[0028] According to the connection impedance of the key channels of the electromagnetic ring network, the connection impedance model between the channels is established;

[0029] According to the primary equipment model and the connection impedance model, a power grid model of the regional power grid to be analyzed under the electromagnetic ring network operation mode is established.

[0030] Optionally, the method further includes:

[0031] Determining whether there is a target risk in the first risk and the second risk;

[0032] When there is a target risk between the first risk and the second risk, generating an alarm prompt for the target risk;

[0033] When there is no target risk in the first risk and the second risk, corresponding risk control suggestions are generated for the first risk and the second risk.

[0034] A second aspect of the present application provides a regional power grid electromagnetic ring network relay protection risk analysis device, the device comprising:

[0035] A data acquisition module is used to obtain basic data of the regional power grid to be analyzed;

[0036] A model building module, used to build a power grid model of the regional power grid to be analyzed under the electromagnetic ring network operation mode based on the basic data;

[0037] A busbar calculation module, used to calculate busbar values ​​of various voltage levels before and after the operation of the electromagnetic ring network based on the power grid model;

[0038] A first analysis module is used to determine a first parameter change of the grid structure of the regional grid to be analyzed before and after the operation of the electromagnetic ring network according to the grid model, and analyze whether there is a first risk in the relay protection based on the first parameter change;

[0039] The second analysis module is used to determine the second parameter change of the grid structure of the regional power grid to be analyzed before and after the operation of the electromagnetic ring network according to the voltage level bus value, and analyze whether there is a second risk in the relay protection based on the second parameter change.

[0040] The third aspect of the present application provides a computer device, which includes a memory, a processor, and a computer program stored in the memory and executable on the processor, and the processor implements the steps of the method for risk analysis of electromagnetic ring network relay protection of the regional power grid when executing the computer program.

[0041] The fourth aspect of the present application provides a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, the steps of the method for risk analysis of electromagnetic ring network relay protection of a regional power grid are implemented.

[0042] This application provides necessary data support for subsequent analysis by obtaining the basic data of the regional power grid to be analyzed, ensuring that the analysis process can be carried out based on accurate and complete power grid information, thereby enhancing the accuracy and reliability of the analysis. By establishing a power grid model under the electromagnetic ring network operation mode of the regional power grid to be analyzed based on the basic data, the power grid state under the electromagnetic ring network operation mode can be simulated, providing a platform for subsequent calculation and analysis. The bus value is an important indicator reflecting the operation state of the power grid. By calculating the bus values ​​of each voltage level before and after the operation of the electromagnetic ring network based on the power grid model, the impact of the change in the power grid structure on the bus voltage and current can be quantitatively evaluated, providing key data support for analyzing whether there is a risk in relay protection. Finally, according to the power grid model, the first parameter change of the power grid structure of the regional power grid to be analyzed before and after the operation of the electromagnetic ring network is determined, and the relay protection is analyzed based on the first parameter change to determine whether there is a first risk; at the same time, according to the voltage level bus value, the second parameter change of the power grid structure of the regional power grid to be analyzed before and after the operation of the electromagnetic ring network is determined, and the relay protection is analyzed based on the second parameter change to determine whether there is a second risk, which can comprehensively and accurately evaluate the risk of relay protection in the regional power grid when the electromagnetic ring network operation mode is adopted. This will help improve the decision-making process for the operation mode of the electromagnetic ring network, reduce the operation risks of the power grid, and improve the operational reliability and safety of the regional power grid. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0044] Figure 1 It is a flow chart of the regional power grid electromagnetic ring network relay protection risk analysis method provided in the embodiment of the present application.

[0045] Figure 2It is a data diagram of the short-circuit resistance of the electromagnetic ring network provided in the embodiment of the present application.

[0046] Figure 3 It is a functional module diagram of the regional power grid electromagnetic ring network relay protection risk analysis device provided in the embodiment of the present application.

[0047] Figure 4 It is a schematic diagram of the structure of a computer device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0048] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0049] During the operation of the regional power grid, when the planned maintenance of equipment at various voltage levels, temporary shutdown due to equipment defects, hidden dangers of wildfires and ice disasters, etc. lead to the inability to operate the entire power grid and the risk of power grid operation increases, in order to maximize the reliability of regional power grid operation, the regional power grid may consider adopting an "electromagnetic ring network" operation mode.

[0050] Relay protection devices are configured in the power system and put into operation at the same time as the primary equipment. They are important basic protection equipment to ensure the safety of the power system. Relay protection devices collect electrical or non-electrical quantity data such as current, voltage, frequency, and temperature of the power system through various sensors such as current transformers. Use secondary cables to connect the relay protection device to the regional power grid and monitor it. The relay protection device monitors the external acquisition signal and determines the operating status of the protected equipment based on the internal logic of the relay protection device. When the relay protection device determines that the protected equipment has an abnormal operating state, it will implement an alarm or trip according to the internally set protection principle to achieve the purpose of isolating the faulty equipment and protecting the safety of the power grid.

[0051] However, the primary and secondary equipment of the regional power grid AC power grid are generally considered in accordance with the "ring network layout, open-loop operation" operation mode. At present, before the regional power grid adopts the electromagnetic ring network operation mode, it usually conducts power grid flow analysis in advance to assess whether there is a risk of equipment load exceeding the power supply capacity during the electromagnetic ring network operation. However, before the regional power grid adopts the electromagnetic ring network operation mode, risk analysis and early warning for relay protection are rarely carried out.

[0052] Due to the lack of risk analysis and early warning for relay protection in the electromagnetic ring network operation mode of the regional power grid, the risk assessment related to relay protection in the electromagnetic ring network operation mode may be insufficient, and the decision to adopt the "electromagnetic ring network" operation mode may be imperfect and unreasonable, which in turn may bring unexpected power grid operation risks.

[0053] Therefore, it is necessary to analyze the risks of relay protection and make corresponding early warnings for the risks before implementing the regional power grid electromagnetic ring network operation mode, so as to facilitate a comprehensive assessment of the necessity of adopting the "regional power grid electromagnetic ring network operation mode".

[0054] like Figure 1 As shown, it is a flow chart of the method for risk analysis of electromagnetic ring network relay protection of a regional power grid provided in an embodiment of the present application. The method for risk analysis of electromagnetic ring network relay protection of a regional power grid includes the following steps.

[0055] S11, obtaining basic data of the regional power grid to be analyzed.

[0056] The regional power grid to be analyzed refers to the specific power grid area where the electromagnetic ring network operation mode analysis and relay protection risk analysis are required. The regional power grid to be analyzed can be a part of a city, a province, or a specific power network area. The purpose of analyzing the regional power grid is to ensure the safety and stability of the regional power grid under the electromagnetic ring network operation mode, as well as the correctness and reliability of the relay protection system.

[0057] In order to prepare for the operation mode of the electromagnetic ring network of the regional power grid, it is necessary to obtain the basic data of the regional power grid to be analyzed. Basic data is a series of detailed information and parameters required for regional power grid analysis. For the operation mode of the electromagnetic ring network and the risk analysis of relay protection, the basic data can include: collecting the interface values ​​of the regional power grid to be analyzed and the adjacent power grids at all levels, the impedance of the key channels of the electromagnetic ring network, the arrangement of the neutral point grounding method of the transformer, the short-circuit level of the transformer, the protection setting value of the equipment to be invested, etc. Figure 2 shown.

[0058] The topology diagram, equipment parameters and operation data of the power grid can be obtained from the power grid planning, design and operation departments. The setting value, configuration and operation status information of the protection device can be obtained from the relay protection department. The real-time operation data and historical data of the power grid can be obtained from the dispatching center.

[0059] The acquired basic data is sorted, classified and stored to form a unified data format and database. The stored basic data can also be checked and verified to ensure the accuracy and completeness of the data.

[0060] S12, establishing a power grid model of the regional power grid to be analyzed under the electromagnetic ring network operation mode based on the basic data.

[0061] An electromagnetic ring network refers to a ring-shaped power grid formed by transmission lines of different voltage levels through transformers or electromagnetic coupling.

[0062] Obtaining the basic data of the regional power grid to be analyzed facilitates the establishment of the corresponding power grid model and constant value ledger, providing a basis for subsequent electromagnetic ring network operation mode and relay protection risk analysis.

[0063] The power grid model is a data set that expresses the properties and connection relationships of power grid equipment, and meets the application requirements of power grid operation monitoring, control, analysis and calculation. The power grid model usually includes information such as the topology of the power grid, the electrical parameters of the equipment, and the operating status, and is the basis for power grid analysis, simulation, and optimization. The power grid model under the electromagnetic ring network operation mode is based on the power grid model, and specifically considers the operating characteristics and influences of the electromagnetic ring network, including the topology of the electromagnetic ring network, the connection impedance of the key channel, the neutral point grounding method of the transformer, and the short-circuit resistance level of the transformer.

[0064] Professional power grid modeling software can be used to build a power grid model of the regional power grid to be analyzed based on basic data. By building a power grid model for simulation testing and simulating the behavior of the power grid under different operating modes and fault conditions, the safety, stability and correctness of the relay protection system of the power grid under the electromagnetic ring network operation mode can be analyzed and evaluated, thereby helping to discover potential problems and risks in power grid operation and provide decision support for optimizing power grid operation.

[0065] In an optional implementation, the establishing of a power grid model of the regional power grid to be analyzed in an electromagnetic ring network operation mode based on the basic data includes:

[0066] Constructing a primary equipment model of the regional power grid to be analyzed according to a primary equipment basic parameter model;

[0067] Importing the protection setting value ledger into the primary equipment model;

[0068] According to the connection impedance of the key channels of the electromagnetic ring network, the connection impedance model between the channels is established;

[0069] According to the primary equipment model and the connection impedance model, a power grid model of the regional power grid to be analyzed under the electromagnetic ring network operation mode is established.

[0070] The parameters related to the primary equipment of the power grid (such as the impedance of the transformer, the capacity of the capacitor, the resistance and reactance of the line, etc.) are obtained from the basic data to build the primary equipment model of the power grid. These primary equipment are the basis of the operation of the power grid, and the primary equipment is electrically connected to form the topological structure of the power grid. Professional power grid modeling software can be used to build the primary equipment model of the power grid based on the sorted primary equipment parameters to accurately reflect the topological structure of the power grid and the electrical characteristics of the equipment.

[0071] The protection setting record is an important part of the power grid protection system, which records the configuration and setting of the protection device. Through the interface or tools provided by the modeling software, the protection setting data in the protection setting record is imported into the primary equipment model, so as to accurately simulate the protection action of the power grid under fault conditions.

[0072] According to the connection impedance of the key channels of the electromagnetic ring network, the connection impedance model between the channels is established to simulate the electrical characteristics of the power grid under the operation mode of the electromagnetic ring network. Professional power grid modeling software is also used to build the connection impedance model between the channels based on the collected connection impedance data.

[0073] Through the interface or tools provided by the power grid modeling software, the primary equipment model and the connection impedance model are imported into a unified power grid model to realize the merger of the primary equipment model and the connection impedance model, thereby obtaining the power grid model of the regional power grid under the electromagnetic ring network operation mode to be analyzed, which is used for subsequent power grid analysis and simulation testing.

[0074] S13, calculating bus values ​​of various voltage levels before and after the operation of the electromagnetic ring network based on the power grid model.

[0075] The busbar value of each voltage level refers to the voltage value presented on the busbars of different voltage levels in the power grid. As the hub of electrical connection in the power grid, the busbar connects electrical equipment such as generators, transformers, and transmission lines to form a complete power system. Busbars of different voltage levels represent the voltage levels of different parts of the power grid. These voltage values ​​are crucial to the stable operation of the power grid, the safe operation of equipment, and the normal power supply of users.

[0076] In the power grid model, the busbar values ​​of each voltage level are obtained through simulation calculation. The busbar values ​​of each voltage level reflect the voltage distribution of the power grid under a specific operation mode. For the comparison before and after the operation of the electromagnetic ring network, the changes in the busbar values ​​of each voltage level can reflect the impact of the change in the power grid structure on the voltage distribution.

[0077] During the specific calculation, the operation mode of the power grid (the current operation mode "big mode" and the electromagnetic ring network operation mode) is input, including the output of each power source, the size and distribution of the load, the switch status of the line, etc. These operation mode data will be used for simulation calculation to obtain the voltage distribution of the power grid under specific conditions. Use professional power grid simulation software to simulate the power grid model. The simulation calculation will consider factors such as power flow distribution, reactive power compensation, and voltage regulation in the power grid to obtain the voltage value on the bus of each voltage level. Finally, the results of the simulation calculation are analyzed to compare the changes in the bus values ​​of each voltage level before and after the operation of the electromagnetic ring network. These changes can reflect the impact of changes in the power grid structure on the voltage distribution.

[0078] The operation mode of the electromagnetic ring network may have a significant impact on the voltage distribution of the power grid. By calculating the bus values ​​of each voltage level before and after the operation of the electromagnetic ring network, the size and scope of this impact can be evaluated, providing an important reference for the dispatch and operation of the power grid. By calculating the bus values ​​of each voltage level before and after the operation of the electromagnetic ring network, the voltage distribution of the power grid under different operation modes can be found, thereby conducting risk analysis on relay protection.

[0079] S14, determining a first parameter change of the grid structure of the regional grid to be analyzed before and after the operation of the electromagnetic ring network according to the grid model, and analyzing whether there is a first risk in relay protection based on the first parameter change.

[0080] Among them, the first parameter change includes one or more combinations of the following: fault current change, boost coefficient change, fault point uncertainty, current protection branch coefficient change, fault current shunting change of equipment within the loop, and fault current change of equipment outside the loop.

[0081] In an optional implementation, the electromagnetic ring network may cause the electrical connection between the regional power grid to be analyzed and the main power grid to be strengthened and the fault current to be increased, and it may be calculated to check whether there is a risk of damage to the relevant transformers listed in the power grid company's list of relevant equipment for preventing damage to equipment due to sudden short circuit of the transformer due to the increase in fault current.

[0082] The established power grid model is used to perform power flow calculation to obtain the power grid power flow distribution before and after the electromagnetic ring network is operated. The power grid power flow distribution can provide parameters such as voltage, current, and power of each node in the power grid. Compare the changes in the fault current in the power flow calculation results before and after the operation of the electromagnetic ring network. If the fault current increases after the operation of the electromagnetic ring network, it is judged that the operation of the electromagnetic ring network has caused the increase of the fault current. Obtain the list of relevant equipment of the power grid company to prevent equipment damage caused by sudden short circuit of the transformer. The list should list all key transformers and their related parameters, such as capacity, short-circuit impedance, etc. According to the parameters of the transformer and the regulations of the manufacturer, determine the maximum fault current threshold that the transformer can withstand. Using the power flow calculation results, calculate the maximum fault current threshold that each transformer may withstand after the operation of the electromagnetic ring network. Compare the calculated fault current with the maximum fault current threshold that the transformer can withstand. If the fault current exceeds the maximum fault current threshold, it can be judged that the transformer is at risk of damage due to increased fault current.

[0083] Appropriate measures can be formulated to reduce or eliminate the risk of transformer damage, such as strengthening the maintenance and management of the transformer, increasing the short-circuit impedance of the transformer, installing current-limiting reactors, etc.

[0084] In an optional implementation, in order to determine whether the auxiliary increase coefficient is increased due to the electromagnetic ring network, it is possible to calculate and check whether there is an electromagnetic ring network that causes the "phase distance section III" and "grounding distance section III" of the 110kV transmission line to fail to meet the regulatory requirements for the remote backup sensitivity of the end-of-line transformer. When the end-of-line transformer or its busbar fails and its protection or circuit breaker fails to operate and requires remote backup action, there is a risk of related line protection failure to operate, resulting in damage to the transformer.

[0085] In an optional implementation, the uncertainty of the fault point of the electromagnetic ring network can be used to calculate and check the electromagnetic ring network, which may cause difficulties in coordinating the multi-level series supply and the electromagnetic ring network-related 110kV line protection cycle, causing the 110kV line protection range to exceed a large range. When the lower-level or even lower-level equipment fails, there is a risk of false protection over-tripping and expanding the power outage area.

[0086] The boost factor is used to describe the degree to which the fault current in a multi-power network is increased due to the boost effect of other power sources. In an electromagnetic ring network, due to the complexity of the grid structure, the fault current may be affected by multiple power sources, resulting in an increase in the boost factor.

[0087] The power flow calculation is performed using the established power grid model to obtain the magnitude and distribution of the fault current. Based on the calculation results of the fault current, the boost coefficient is calculated. The boost coefficient can be obtained by comparing the fault current with the fault current when a single power supply is used. The calculated boost coefficient is compared with the boost coefficient before the electromagnetic ring network is operated. If the boost coefficient increases, it can be determined that the electromagnetic ring network has an impact on the boost coefficient.

[0088] According to the requirements of the regulations and the actual situation of the power grid, the protection settings of the "phase-to-phase distance section III" and "ground distance section III" of the 110kV transmission line are calculated. These settings include impedance settings and time settings. The sensitivity of the protection settings is checked using the power grid model and fault analysis results. The contents of the check include whether the protection can correctly identify the fault, whether the fault removal time meets the requirements, etc. The check results are compared with the requirements of the regulations. If the protection sensitivity does not meet the requirements of the regulations, it is necessary to further evaluate the impact of the fault on the power grid, the possibility of transformer damage, and possible economic losses. When the end-of-line transformer or its busbar fails and its protection or circuit breaker fails to operate and requires remote backup action, special attention should be paid to the risk of refusal of the relevant line protection. This can be obtained by simulating the fault situation and performing detailed analysis and calculation.

[0089] Based on the risk assessment results, corresponding measures can be formulated to reduce or eliminate risks, such as adjusting protection settings, optimizing grid structure, and strengthening equipment maintenance.

[0090] In an optional implementation, the risk of incomplete coordination between the "zero-sequence protection" of the backup protection on the 110kV side of the 220kV main transformer and the adjacent 110kV outgoing line in the electromagnetic ring network caused by the electromagnetic ring network can be calculated and checked in order to address the increase in the current protection branch coefficient caused by the electromagnetic ring network.

[0091] Fault point uncertainty refers to the difficulty in accurately predicting and determining the specific location of the fault point in the power system due to the complexity of the grid structure, the diversity of fault types and the randomness of the fault location.

[0092] Fault simulation is performed based on the established power grid model. By simulating different fault types and locations, the distribution and change of fault current are calculated to evaluate the uncertainty of the fault point. The fault recording device is used to record the waveform data of current, voltage, etc. when the fault occurs. By analyzing the waveform data, the approximate location and type of the fault can be inferred.

[0093] The existence of electromagnetic ring network will lead to multi-level series supply phenomenon, that is, the fault current may be transmitted through multiple power supply points or lines, making it more difficult to determine the fault point. At the same time, the electromagnetic ring network will also complicate the protection coordination of related 110kV lines, which may cause problems such as protection range exceeding far and protection overstepping malfunction.

[0094] According to the requirements of the regulations and the actual situation of the power grid, the protection setting value of the 110kV line is calculated. Then, the protection setting value is verified using the results of the fault simulation analysis. The verification content includes whether the protection can correctly identify the fault and whether the fault removal time meets the requirements.

[0095] On the basis of protection setting verification, the influence of electromagnetic ring network on the coordination of related 110kV line protection is analyzed. Special attention is paid to whether the protection range is too far and whether there is a risk of misoperation of protection overstepping. By comparing the coordination relationship between different protections, possible problems and hidden dangers can be found.

[0096] Based on the results of the analysis, formulate corresponding risk prevention and control measures, such as adjusting protection settings, optimizing the grid structure, and strengthening equipment maintenance.

[0097] In an optional implementation, the electromagnetic ring network can be used to cause current diversion of equipment faults within the ring, and the zero-sequence sensitivity segment of the 110kV line protection can be calculated and checked to find that its sensitivity to line-end faults is far lower than the sensitivity coefficient of 1.5 required by the regulations, and that the sensitivity requirement can only be met by the last segment of the zero-sequence segment. There is a risk of equipment damage due to excessive protection action time.

[0098] The fault current is calculated using the power grid model to simulate the impact of equipment failure in the electromagnetic ring network on the fault current and the distribution of the fault current among the equipment in the ring.

[0099] According to the regulations, the sensitivity coefficient of the zero-sequence sensitivity section of the 110kV line protection to the line end fault should not be less than 1.5. The fault current calculation results are used to verify whether the actual sensitivity coefficient meets this requirement.

[0100] If the test result shows that the sensitivity coefficient does not meet the requirements, the protection setting value needs to be adjusted to increase the sensitivity coefficient of the zero-sequence sensitivity section. The influence of the electromagnetic ring network should be considered during the adjustment to ensure that the protection can operate correctly when the equipment in the ring fails.

[0101] Analyze whether the protection action time is too long, especially when relying on the last segment of the zero sequence to meet the sensitivity requirements. If the action time is too long, it may increase the risk of equipment damage.

[0102] Assess the impact of actuation time on equipment safety and whether additional protective measures are needed to shorten actuation time.

[0103] According to the analysis results, the electromagnetic ring network can be modified or optimized to reduce the shunting phenomenon of fault current. For example, the grid structure can be improved by adding transmission lines, adjusting the transformer connection method, etc.

[0104] In an optional implementation, the value of the last segment of the zero sequence retained for the 110kV line protection related to the electromagnetic ring network based on the remote backup sensitivity can be set lower than 120A. Calculation and investigation show that this constant value cannot reliably avoid the unbalanced current generated at the maximum load. There is a risk that the electromagnetic ring network N-1 causes power flow transfer and the last segment of the zero sequence trips incorrectly when the load is too heavy, resulting in the 110kV loop being disconnected.

[0105] Collect data on the protection configuration, set value settings, and operation mode of the 110kV lines related to the electromagnetic ring network. Obtain current data at maximum load, as well as the calculation method and standard for unbalanced current. Calculate the unbalanced current generated at maximum load based on the collected data. Evaluate the magnitude of the unbalanced current and whether it may affect the last segment of the zero sequence. Compare the calculated unbalanced current with the set value of the last segment of the zero sequence. If the unbalanced current is greater than the set value, there is a risk of false tripping.

[0106] Consider the power flow transfer and load changes of the electromagnetic ring network under the condition of N-1 (i.e. one component failure). Analyze the impact of power flow transfer on the last segment of zero sequence and whether it may cause false tripping. If the last segment of zero sequence falsely trips, evaluate the impact on the 110kV power grid.

[0107] If the calculation results show that the unbalanced current may be greater than the set value of the last segment of the zero sequence, the set value should be adjusted. When adjusting the set value, the sensitivity and reliability of the protection should be comprehensively considered to ensure that the unbalanced current can be reliably avoided and the fault can be correctly identified.

[0108] In an optional implementation, in response to the increase in fault current of equipment outside the electromagnetic ring network, it is possible to calculate and check that the sensitivity of the zero-sequence protection of the 110kV line increases by a multiple far higher than the sensitivity coefficient of 1.5 required by the regulations compared with the normal operating mode, and the protection range extends far. There is a risk that the protection will trip at the next level when the lower-level equipment fails, expanding the power outage area.

[0109] When a fault occurs in the equipment outside the electromagnetic ring network, the fault current may propagate through the electromagnetic ring network, causing the sensitivity coefficient of the 110kV line zero-sequence protection to increase abnormally. If the sensitivity coefficient is much higher than the 1.5 required by the regulations, it may mean that the protection device is too sensitive to the fault and is prone to misoperation.

[0110] Due to the increase in sensitivity, the protection range of the 110kV line zero-sequence protection may extend far, even covering the lower-level equipment. This may cause the upper 110kV line zero-sequence protection to malfunction when the lower-level equipment fails, causing over-tripping. Over-tripping will cause unnecessary large-scale power outages, causing serious impacts on normal production order and residents' lives. In the electromagnetic ring network, due to the multi-path propagation of fault current and the complexity of protection, the risk of over-tripping may be higher.

[0111] Recalculate and adjust the setting of 110kV line zero-sequence protection according to the actual operation of the electromagnetic ring network and the characteristics of the fault current. Ensure that the sensitivity coefficient is within the range required by the regulations to avoid over-sensitive or sluggish protection. Consider adding additional protection devices at key nodes of the electromagnetic ring network. By optimizing the protection configuration, improve the reliability and selectivity of the protection and reduce the risk of false operation and over-tripping.

[0112] In an optional implementation, the electromagnetic ring network may cause fault current shunting of equipment within the ring, and the risk of the remote backup sensitivity of the last section of the 110kV line zero sequence to the adjacent lower-level 110kV line not meeting the regulatory requirements may be calculated and checked.

[0113] The fault current is calculated using the power grid model to simulate the current diversion when a device fails within the ring, as well as the distribution of the fault current among the devices within the ring.

[0114] According to the regulations, the remote backup sensitivity of the last section of the 110kV line zero sequence to the adjacent lower 110kV line is verified. Remote backup sensitivity refers to the ability of the upper line protection device to correctly identify and operate when a fault occurs in the adjacent lower line.

[0115] If the verification results show that the remote backup sensitivity does not meet the requirements of the regulations, there is a risk. Assess the size of the risk and the possible consequences, including whether it may cause the upper protection to malfunction or refuse to operate when the lower equipment fails, thereby expanding the power outage area.

[0116] According to the results of fault current calculation and remote backup sensitivity verification, adjust the protection setting of the last section of the zero sequence of the 110kV line. Ensure that the protection setting can not only meet the requirements of the regulations, but also reliably protect the adjacent lower-level lines. Additional protection devices can be added at the key nodes of the electromagnetic ring network. By optimizing the protection configuration, the reliability and selectivity of the protection can be improved, and the risk of false operation and refusal to operate can be reduced.

[0117] In an optional implementation, the branch coefficient and auxiliary increase coefficient caused by the electromagnetic ring network can be changed, and the risks of mismatch points of "zero-sequence overcurrent protection", "grounding distance" and "phase-to-phase distance" of 220kV or 110kV line protection under the jurisdiction of the regional power grid where the electromagnetic ring network is added can be calculated and checked.

[0118] The existence of electromagnetic ring network will make the grid structure complicated, which will affect the calculation of branch coefficient and auxiliary increase coefficient. The change of branch coefficient and auxiliary increase coefficient will directly affect the setting and coordination of line protection.

[0119] According to the actual structure and operation mode of the power grid, the branch coefficient and auxiliary increase coefficient of each line are calculated. Combined with the calculation results of the branch coefficient and auxiliary increase coefficient, analyze whether there are mismatch points in the "zero-sequence overcurrent protection", "grounding distance" and "phase-to-phase distance" of the 220kV or 110kV line protection. Mismatch points may cause malfunction or refusal of protection, thus affecting the safe and stable operation of the power grid.

[0120] Determine the risk level based on the severity of the mismatch point and the possible consequences. Prioritize high-risk mismatch points to ensure the safety of the power grid.

[0121] According to the changes of branch coefficient and auxiliary increase coefficient, the fixed value of line protection is readjusted to ensure that the protection fixed value can meet the requirements of regulations and adapt to the changes brought by electromagnetic ring network.

[0122] In an optional implementation, in addition to using setting calculation software or tools to perform calculations and troubleshooting for protection range exceeding or protection sensitivity insufficient caused by the electromagnetic ring network, a fault calculation tool can also be used to calculate the fault current, voltage and other reserve quantities, and then the risk of related protection overstepping or refusal to operate under the electromagnetic ring network operation mode can be evaluated based on the "zero-sequence overcurrent protection", "grounding distance" and "phase-to-phase distance" measurement values.

[0123] The fault calculation tool can be used to simulate the current and voltage distribution of the electromagnetic ring network under different fault conditions. By inputting information such as the topology of the power grid, component parameters, and fault type, the fault calculation tool can output key data such as the current, voltage, and current distribution of each branch at the fault point.

[0124] Based on the data output by the fault calculation tool, the required reserve for protection can be further calculated, such as the effective value and peak value of the fault current and the amplitude of the fault voltage.

[0125] In the electromagnetic ring network operation mode, the zero-sequence current distribution of each line is calculated and compared with the protection setting value. If the actual zero-sequence current exceeds the protection setting value, there may be a risk of exceeding the protection range; conversely, if the actual zero-sequence current is too small, it may lead to insufficient protection sensitivity.

[0126] According to the fault voltage and current data output by the fault calculation tool, the grounding distance and phase distance of each line are calculated. The calculated distance value is compared with the setting value of the protection to evaluate whether there is a risk of overstepping or refusal to operate the protection.

[0127] Combined with the above calculation results, the risks of related protection under the electromagnetic ring network operation mode are quantitatively evaluated. The risk level is determined, and high-risk areas and key lines are identified. Targeted response measures are formulated for high-risk areas and key lines, such as adjusting protection setting values, optimizing protection configuration, and strengthening power grid monitoring and early warning.

[0128] S15, determining a second parameter change of the grid structure of the regional grid to be analyzed before and after the operation of the electromagnetic ring network according to the voltage level bus value, and analyzing whether there is a second risk in the relay protection based on the second parameter change.

[0129] Before and after the operation of the electromagnetic ring network, the parameter change of the grid structure (ie, the second parameter change) is determined according to the change of the voltage level bus value, and based on the parameter change, it is analyzed whether there is a potential risk in the relay protection.

[0130] The second parameter change refers to the change in the parameters related to the voltage level bus value (such as bus value impedance) in the power grid structure before and after the operation of the electromagnetic ring network. Correspondingly, the second risk refers to the problems in relay protection that may be caused by the change in the power grid structure parameters (such as excessive drop in bus value impedance) caused by the operation of the electromagnetic ring network, such as protection malfunction, refusal to operate, or protection range exceeding.

[0131] In an optional implementation, analyzing whether there is a second risk in relay protection based on the change of the second parameter includes:

[0132] When the busbar impedance decreases by more than the preset decrease threshold, analyze whether there is a risk of power outage expansion and difficulty in fault finding and recovery due to protection overstepping when the lower-level equipment fails. Determine whether the busbar impedance decreases by more than the preset threshold.

[0133] Obtain the bus impedance value before the electromagnetic ring network is operated (ie, normal operation), and obtain the bus impedance value after the electromagnetic ring network is operated. Bus impedance drop = (bus impedance value before operation - bus impedance value after operation) / bus impedance value before operation × 100%.

[0134] If the bus impedance drops beyond the preset drop threshold, it may affect the relay protection. Therefore, after obtaining the bus impedance drop, it is necessary to analyze whether the protection range of the original protection setting of the bus-related power supply equipment has been exceeded, and whether it will lead to risks such as protection overstepping and false operation when the lower-level equipment fails.

[0135] When the busbar impedance drops by more than the preset threshold, a simulation analysis is performed to determine whether the relay protection will malfunction due to a fault in the lower-level equipment, thereby increasing the power outage area and increasing the risk of difficulty in fault finding and recovery.

[0136] It should be understood that the embodiment of the present application determines the changes in the grid structure parameters of the regional grid before and after the operation of the electromagnetic ring network based on the grid model and the voltage level bus value, and analyzes whether there are risks in the relay protection based on these parameter changes. The reason is:

[0137] The grid model provides an overall description of the grid structure, including the connection methods and parameters of components such as lines, transformers, and busbars. By comparing the grid models before and after the operation of the electromagnetic ring network, the changes in the grid structure can be intuitively seen, such as the addition or removal of lines, changes in transformer ratios, etc. These changes may directly affect the configuration and setting values ​​of relay protection.

[0138] The voltage level bus value is an important reflection of the power grid operation status, which is directly related to the current and voltage distribution in the power grid. By comparing the bus values ​​before and after the operation of the electromagnetic ring network, the changes in the power grid operation status can be evaluated, such as voltage increase or decrease, current increase or decrease, etc. These changes may also affect the relay protection, such as the sensitivity or action range of overcurrent protection, distance protection, etc. may change.

[0139] Combining the power grid model and the voltage level bus value for analysis, the impact of electromagnetic ring network operation on relay protection can be comprehensively evaluated from both the structural and operational levels, which helps to improve the accuracy of the analysis and reduce the risk points that may be missed due to a single analysis angle. By quantifying parameter changes (such as line impedance changes, bus voltage changes, etc.), the impact of these changes on relay protection devices can be more accurately evaluated, thereby more accurately determining whether there is a risk.

[0140] In an optional embodiment, the method further comprises:

[0141] Determining whether there is a target risk in the first risk and the second risk;

[0142] When there is a target risk between the first risk and the second risk, generating an alarm prompt for the target risk;

[0143] When there is no target risk in the first risk and the second risk, corresponding risk control suggestions are generated for the first risk and the second risk.

[0144] All analyzed first risks (risks related to equipment damage, protection refusal, malfunction, etc. caused by electromagnetic ring network) and second risks (risks related to large busbar equivalent impedance drop and protection range exceeding caused by electromagnetic ring network) are evaluated to determine whether there are uncontrollable risks, such as equipment damage risks. Uncontrollable risks are target risks.

[0145] When there is a target risk in the first risk and the second risk, an alarm will be generated to notify relevant personnel to pay attention to these risks and may need to take emergency measures to eliminate or mitigate these risks. The alarm can immediately attract the attention of relevant personnel, ensuring that relevant personnel can respond and handle risks quickly to prevent risks from further developing or causing serious consequences.

[0146] When there is no target risk in the first risk and the second risk, but there are still some non-urgent risks, risk control suggestions are generated for these risks. These suggestions include preventive measures, improvement measures or monitoring measures, etc., which are aimed at reducing the possibility of risk occurrence or mitigating the impact of risk. By generating risk control suggestions, guidance and assistance can be provided to relevant personnel, so that relevant personnel can take targeted measures to reduce risks and improve the safety and reliability of the power grid. At the same time, risk control suggestions can also serve as a reference for future power grid planning and design to avoid the recurrence of similar risks.

[0147] The above optional implementation method realizes real-time monitoring and early warning of power grid security risks caused by the electromagnetic ring network by judging whether there is a target risk between the first risk and the second risk, and generating an alarm prompt or risk control suggestion according to the judgment result.

[0148] The method for analyzing the risk of relay protection of electromagnetic ring network of regional power grid provided in the embodiment of the present application provides necessary data support for subsequent analysis by obtaining the basic data of the regional power grid to be analyzed, ensuring that the analysis process can be carried out based on accurate and complete power grid information, thereby enhancing the accuracy and reliability of the analysis. By establishing a power grid model under the operation mode of the electromagnetic ring network of the regional power grid to be analyzed based on the basic data, the power grid state under the operation mode of the electromagnetic ring network can be simulated, providing a platform for subsequent calculation and analysis. The bus value is an important indicator reflecting the operation state of the power grid. By calculating the bus values ​​of each voltage level before and after the operation of the electromagnetic ring network based on the power grid model, the influence of the change of the power grid structure on the bus voltage and current can be quantitatively evaluated, providing key data support for analyzing whether there is a risk in relay protection. Finally, the parameter changes of the power grid structure of the regional power grid to be analyzed before and after the operation of the electromagnetic ring network are determined according to the power grid model and the bus value of the voltage level, and whether there is a risk in relay protection is analyzed based on the parameter changes, which can comprehensively and accurately evaluate the risk of relay protection of the regional power grid when the electromagnetic ring network operation mode is adopted. This helps to improve the decision-making process of the electromagnetic ring network operation mode, reduce the risk of power grid operation, and improve the reliability and safety of the operation of the regional power grid.

[0149] Figure 3 It is a functional module diagram of the regional power grid electromagnetic ring network relay protection risk analysis device provided in the embodiment of the present application.

[0150] In some embodiments, the regional power grid electromagnetic ring network relay protection risk analysis device 30 may include a plurality of functional modules composed of program code segments. The program code of each program segment in the regional power grid electromagnetic ring network relay protection risk analysis device 30 may be stored in the memory of a computer device and executed by at least one processor to execute (see Figure 1 Description) Function of relay protection risk analysis.

[0151] In this embodiment, the regional power grid electromagnetic ring network relay protection risk analysis device 30 can be divided into multiple functional modules according to the functions it performs. The functional modules may include: a data acquisition module 301, a model building module 302, a bus calculation module 303, a first analysis module 304, a second analysis module 305, a risk judgment module 306, a first generation module 307 and a second generation module 308. The module referred to in this application refers to a series of computer-readable instruction segments that can be executed by at least one processor and can complete fixed functions, which are stored in a memory. In this embodiment, the functions of each module will be described in detail in subsequent embodiments.

[0152] The data acquisition module 301 is used to acquire basic data of the regional power grid to be analyzed;

[0153] The model building module 302 is used to build a power grid model under the electromagnetic ring network operation mode of the regional power grid to be analyzed based on the basic data;

[0154] The bus calculation module 303 is used to calculate the bus values ​​of each voltage level before and after the operation of the electromagnetic ring network based on the power grid model;

[0155] The first analysis module 304 is used to determine, according to the power grid model, a first parameter change of the power grid structure of the regional power grid to be analyzed before and after the operation of the electromagnetic ring network, and analyze whether there is a first risk in the relay protection based on the first parameter change;

[0156] The second analysis module 305 is used to determine the second parameter change of the grid structure of the regional grid to be analyzed before and after the operation of the electromagnetic ring network according to the voltage level bus value, and analyze whether there is a second risk in the relay protection based on the second parameter change;

[0157] The risk determination module 306 is used to determine whether there is a target risk in the first risk and the second risk;

[0158] The first generating module 307 is configured to generate an alarm prompt for a target risk when there is a target risk between the first risk and the second risk;

[0159] The second generating module 308 is configured to generate corresponding risk control suggestions for the first risk and the second risk when there is no target risk in the first risk and the second risk.

[0160] It should be understood that the various variations and specific embodiments of the regional power grid electromagnetic ring network relay protection risk analysis method provided in the above-mentioned embodiment are also applicable to the regional power grid electromagnetic ring network relay protection risk analysis device in this embodiment. Through the detailed description of the aforementioned regional power grid electromagnetic ring network relay protection risk analysis method, technical personnel in this field can clearly know the implementation process of the regional power grid electromagnetic ring network relay protection risk analysis device in this embodiment. For the sake of brevity of the specification, it will not be described in detail here.

[0161] The regional power grid electromagnetic ring network relay protection risk analysis device provided in the embodiment of the present application provides necessary data support for subsequent analysis by obtaining the basic data of the regional power grid to be analyzed, ensuring that the analysis process can be carried out based on accurate and complete power grid information, thereby enhancing the accuracy and reliability of the analysis. By establishing a power grid model under the operation mode of the electromagnetic ring network of the regional power grid to be analyzed based on the basic data, the power grid state under the operation mode of the electromagnetic ring network can be simulated, providing a platform for subsequent calculation and analysis. The bus value is an important indicator reflecting the operation state of the power grid. By calculating the bus values ​​of each voltage level before and after the operation of the electromagnetic ring network based on the power grid model, the influence of the change in the power grid structure on the bus voltage and current can be quantitatively evaluated, providing key data support for analyzing whether there is a risk in relay protection. Finally, the parameter changes of the power grid structure of the regional power grid to be analyzed before and after the operation of the electromagnetic ring network are determined according to the power grid model and the bus value of the voltage level, and the risk of relay protection is analyzed based on the parameter changes, which can comprehensively and accurately evaluate the risk of relay protection of the regional power grid when the electromagnetic ring network operation mode is adopted. This helps to improve the decision-making process of the electromagnetic ring network operation mode, reduce the risk of power grid operation, and improve the reliability and safety of the operation of the regional power grid.

[0162] An embodiment of the present application also provides a computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, all or part of the steps of the method for risk analysis of electromagnetic ring network relay protection of a regional power grid are implemented.

[0163] See also Figure 4 FIG. 4 is a schematic diagram of the structure of a computer device provided in an embodiment of the present application. In a preferred embodiment of the present application, the computer device 4 includes a memory 401 , at least one processor 402 , and at least one communication bus 403 .

[0164] Those skilled in the art should understand that Figure 4 The structure of the computer device shown does not constitute a limitation of the embodiments of the present application. The computer device 4 may also include more or less other hardware or software than shown in the figure, or a different arrangement of components.

[0165] In some embodiments, the computer device 4 is a device that can automatically perform numerical calculations and / or information processing according to pre-set or stored instructions, and its hardware includes but is not limited to microprocessors, application-specific integrated circuits, programmable gate arrays, digital processors, and embedded devices. The computer device 4 may also include client devices, which include but are not limited to any electronic product that can interact with the client through a keyboard, mouse, remote control, touchpad, or voice control device, such as a personal computer, tablet computer, smart phone, digital camera, etc.

[0166] It should be noted that the computer device 4 is only an example, and other existing or future electronic products that are suitable for the present application should also be included in the protection scope of the present application and included here by reference.

[0167] In some embodiments, the memory 401 stores a computer program, and when the computer program is executed by the at least one processor 402, all or part of the steps in the method for risk analysis of electromagnetic ring network relay protection of the regional power grid are implemented. The memory 401 includes a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), a one-time programmable read-only memory (OTPROM), an electronically erasable programmable read-only memory (EEPROM), a compact disc read-only memory (CD-ROM) or other optical disc storage, magnetic disk storage, magnetic tape storage, or any other computer-readable medium that can be used to carry or store data. Further, the computer-readable storage medium may mainly include a program storage area and a data storage area, wherein the program storage area may store an operating system, an application required for at least one function, and the like.

[0168] In some embodiments, the at least one processor 402 is the control core (CrolUnit) of the computer device 4, and uses various interfaces and lines to connect the various components of the entire computer device 4, and executes various functions and processes data of the computer device 4 by running or executing the program or module stored in the memory 401, and calling the data stored in the memory 401. For example, when the at least one processor 402 executes the computer program stored in the memory, it implements all or part of the steps of the method for risk analysis of electromagnetic ring network relay protection of the regional power grid described in the embodiment of the present application; or implements all or part of the functions of the device for risk analysis of electromagnetic ring network relay protection of the regional power grid. The at least one processor 402 can be composed of an integrated circuit, for example, it can be composed of a single packaged integrated circuit, or it can be composed of multiple integrated circuits with the same function or different functions, including one or more central processing units (CPU), microprocessors, digital processing chips, graphics processors, and various control chips.

[0169] In some embodiments, the at least one communication bus 403 is configured to realize connection and communication between the memory 401 and the at least one processor 402, etc. Although not shown, the computer device 4 may also include a power supply (such as a battery) for powering each component. Preferably, the power supply may be logically connected to the at least one processor 402 through a power management device, so as to realize functions such as management of charging, discharging, and power consumption management through the power management device. The power supply may also include any components such as one or more DC or AC power supplies, recharging devices, power failure detection circuits, power converters or inverters, power status indicators, etc. The computer device 4 may also include a variety of sensors, Bluetooth modules, Wi-Fi modules, etc., which will not be repeated here.

[0170] The above-mentioned integrated unit implemented in the form of a software function module can be stored in a computer-readable storage medium. The above-mentioned software function module is stored in a storage medium, including a number of instructions for enabling a computer device (which can be a personal computer, a computer device, or a network device, etc.) or a processor to execute part of the method described in each embodiment of the present application.

[0171] In the several embodiments provided in this application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are only illustrative, for example, the division of the modules is only a logical function division, and there may be other division methods in actual implementation.

[0172] The modules described as separate components may or may not be physically separated, and the components shown as modules may or may not be physical units, and may be located in one place or distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

Claims

1. A method for risk analysis of electromagnetic ring network relay protection in a regional power grid, characterized in that: The regional power grid electromagnetic ring network relay protection risk analysis method includes: Obtain basic data of the regional power grid to be analyzed; Based on the basic data, a power grid model of the regional power grid to be analyzed under the electromagnetic ring network operation mode is established; Based on the power grid model, bus values ​​of various voltage levels before and after the operation of the electromagnetic ring network are calculated; Determine, according to the power grid model, a first parameter change of the power grid structure of the regional power grid to be analyzed before and after the operation of the electromagnetic ring network, and analyze whether there is a first risk in relay protection based on the first parameter change; A second parameter change of the grid structure of the regional power grid to be analyzed before and after the operation of the electromagnetic ring network is determined according to the voltage level bus value, and based on the second parameter change, it is analyzed whether there is a second risk in the relay protection.

2. The method for risk analysis of electromagnetic ring network relay protection in a regional power grid according to claim 1, characterized in that: The first parameter change includes one or more combinations of the following: Changes in fault current, changes in auxiliary coefficient, uncertainty in fault point, changes in current protection branch coefficient, changes in fault current shunting of equipment within the loop, and changes in fault current of equipment outside the loop.

3. The method for risk analysis of electromagnetic ring network relay protection in a regional power grid according to claim 2, characterized in that: The analyzing whether there is a first risk in relay protection based on the first parameter change includes one or more combinations of the following: When the fault current of the electromagnetic ring network increases, analyze whether the transformer is at risk of being damaged due to the increase in fault current; When the electromagnetic ring network auxiliary increase coefficient increases, the risk of transformer damage caused by insufficient remote backup sensitivity of 110kV line protection is analyzed; When the fault point of the electromagnetic ring network is uncertain and the coordination of multi-level series supply and protection is difficult, analyze whether there is a risk of protection over-level misoperation and expanding power outage; When the electromagnetic ring network causes the current protection branch coefficient to increase, analyze whether there is a risk of incomplete coordination between the 220kV main transformer backup protection and the 110kV outgoing line; When the fault current of the equipment in the electromagnetic ring network is shunted, analyze whether there is a risk of long protection action time causing equipment damage; When the value of the last segment of the zero sequence protection of the 110kV line is lower than the threshold, analyze whether there is a risk of false tripping and ring release caused by the electromagnetic ring network N-1; When the fault current of the equipment outside the electromagnetic ring network increases, analyze whether there is a risk of protection tripping when the lower-level equipment fails; When the electromagnetic ring network causes fault current shunting of equipment within the ring, analyze whether there is a risk that the remote backup sensitivity of the last section of the 110kV line zero sequence to the adjacent lower-level line does not meet the requirements.

4. The method for risk analysis of electromagnetic ring network relay protection in a regional power grid according to claim 1, characterized in that: The second parameter change includes bus value impedance.

5. The method for risk analysis of electromagnetic ring network relay protection in a regional power grid according to claim 4, characterized in that: The analyzing whether the relay protection has a second risk based on the change of the second parameter includes: When the busbar impedance drop exceeds the preset drop threshold, analyze whether there is a risk of power outage area expansion and difficulty in fault finding and recovery due to protection over-trip malfunction when the lower-level equipment fails.

6. The method for risk analysis of electromagnetic ring network relay protection in a regional power grid according to claim 1, characterized in that: The step of establishing a power grid model under the electromagnetic ring network operation mode of the regional power grid to be analyzed based on the basic data includes: Constructing a primary equipment model of the regional power grid to be analyzed according to a primary equipment basic parameter model; Importing the protection setting value ledger into the primary equipment model; According to the connection impedance of the key channels of the electromagnetic ring network, the connection impedance model between the channels is established; According to the primary equipment model and the connection impedance model, a power grid model of the regional power grid to be analyzed under the electromagnetic ring network operation mode is established.

7. The method for risk analysis of electromagnetic ring network relay protection in a regional power grid according to claim 1, characterized in that: The regional power grid electromagnetic ring network relay protection risk analysis method also includes: Determining whether there is a target risk in the first risk and the second risk; When there is a target risk between the first risk and the second risk, generating an alarm prompt for the target risk; When there is no target risk in the first risk and the second risk, corresponding risk control suggestions are generated for the first risk and the second risk.

8. A risk analysis device for electromagnetic ring network relay protection of a regional power grid, characterized in that: The regional power grid electromagnetic ring network relay protection risk analysis device comprises: A data acquisition module is used to obtain basic data of the regional power grid to be analyzed; A model building module, used to build a power grid model under the electromagnetic ring network operation mode of the regional power grid to be analyzed based on the basic data; A busbar calculation module, used to calculate busbar values ​​of various voltage levels before and after the operation of the electromagnetic ring network based on the power grid model; A first analysis module is used to determine a first parameter change of the grid structure of the regional grid to be analyzed before and after the operation of the electromagnetic ring network according to the grid model, and analyze whether there is a first risk in the relay protection based on the first parameter change; The second analysis module is used to determine the second parameter change of the grid structure of the regional power grid to be analyzed before and after the operation of the electromagnetic ring network according to the voltage level bus value, and analyze whether there is a second risk in the relay protection based on the second parameter change.

9. A computer device, characterized in that: The computer device includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the steps of the method for risk analysis of electromagnetic ring network relay protection of a regional power grid as described in any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by the processor, the steps of the method for risk analysis of electromagnetic ring network relay protection of a regional power grid as described in any one of claims 1 to 7 are implemented.

Images