Relay protection equipment simulation system based on virtual digitization

Abstract

The invention discloses a relay protection equipment simulation system based on virtual digitization, and the system comprises a fault scene construction unit which is used for simulating various faults, and setting the fault occurrence time, position, duration time and fault type; the power system model building unit is used for simulating the dynamic change of electromagnetic characteristics during the fault occurrence period by using a transformer model; simulating the wave process and transient characteristics of the power transmission line and the distribution rule of voltage and current along the line by using the power transmission line model; simulating the dynamic change of the load by using the load model; the calculation unit is used for dividing a power grid into discrete networks based on a time domain finite difference algorithm of a node voltage method and carrying out discretization processing on time and space; and the whole process fault simulation unit simulates the whole process of fault occurrence in stages. According to the system, a comprehensive, accurate and dynamic simulation environment can be provided for relay protection equipment testing and power system fault analysis, and the safety and reliability of a power system can be improved.

Description

Technical Field

[0001] The present invention relates to the field of power system simulation, and more particularly to a relay protection equipment simulation system based on virtual digitization. Background Art

[0002] With the continuous development of smart grids, relay protection equipment serves as a crucial line of defense for the safe and stable operation of power systems. Its performance is directly related to the reliable operation of the power grid. However, existing relay protection equipment simulation systems face numerous technical challenges in practical applications. Traditional simulation methods often use simplified models for components such as transformers and transmission lines. This results in simulations that fail to accurately reflect the current and voltage distortions at the moment of a fault, thereby affecting the accuracy of protective device operation. Existing protection logic is often designed based on offline threshold settings. Under complex operating conditions, this can easily lead to false or failed protection device operation, reducing grid reliability. As the scale and complexity of power grids continue to expand, traditional centralized computing architectures are struggling to process the massive amounts of data. This is particularly true when simulating multiple fault propagation paths, where slow computation speeds and high resource consumption become increasingly prominent, making it difficult to meet the demands of real-time simulation. Summary of the Invention

[0003] The present invention provides a relay protection equipment simulation system based on virtual digitization, which can provide a comprehensive, accurate and dynamic simulation environment for relay protection equipment testing and power system fault analysis, and can improve the safety and reliability of the power system.

[0004] In order to achieve these objectives and other advantages of the present invention, a relay protection device simulation system based on virtual digitization is provided, comprising: Fault scenario construction unit, which is used to simulate various faults of transmission lines of different voltage levels and set the time, location, duration and type of fault; A power system model building unit is connected to the fault scenario building unit, and the fault scenario building unit provides fault parameters to the power system model building unit. The power system model building unit includes: using a transformer model and its key parameters to simulate the dynamic changes of electromagnetic characteristics during a fault; using a transmission line model and a model reflecting distributed parameters to simulate the wave process, transient characteristics, and distribution law of voltage and current along the transmission line; using a load model and various load types to simulate the dynamic changes of loads under different working conditions; and using a relay protection device model to simulate various protection types. a calculation unit connected to the power system model building unit, wherein the calculation unit divides the power grid of the power system model into discrete networks based on a time-domain finite-difference algorithm of a node voltage method, and discretizes time and space to achieve an accurate simulation of the dynamic changes of current and voltage from the moment of fault occurrence to the entire process of fault removal; The whole process fault simulation unit is connected to the calculation unit and simulates the whole process of fault occurrence in stages according to the results of the calculation unit.

[0005] Preferably, the full-process fault simulation unit specifically includes: an initialization subunit, which is used to initialize the operation; a fault occurrence subunit, which is used to simulate the occurrence of a fault when the simulation time reaches a preset fault moment; a fault development subunit, which is used to continuously simulate the propagation process of the fault in the power grid as time goes by; and a protection action subunit, which is used to issue a protection action according to a preset action logic when the relay protection device detects that the fault current exceeds the action threshold.

[0006] Preferably, it further includes a multi-dimensional result display unit, which includes: The current and voltage change curve unit uses a visual interface to draw the current and voltage change curves of each key node during the fault period, with time as the horizontal axis and current and voltage amplitudes as the vertical axis; The relay protection device working process display unit displays the action sequence, time delay and working logic execution of the relay protection device in the form of a timeline; The state change display unit displays the state changes of power grid equipment during the fault process through a 3D model.

[0007] Preferably, the fault scenario construction unit specifically includes: The fault type generation module uses a deep learning algorithm to analyze a large amount of historical fault data, real-time grid parameters, and power system status monitoring data. By building a fault pattern recognition model, it generates fault types for transmission lines at different voltage levels. A spatiotemporal parameter setting module, to which the fault location information determined by the GIS platform is transmitted in real time; a time signal provided by a real-time clock synchronization system is transmitted in real time to the spatiotemporal parameter setting module, providing an accurate time reference for the full-process fault simulation unit; and the calculation results of the fault duration calculation model are fed back to the spatiotemporal parameter setting module, enabling the full-process fault simulation unit to control the duration of the fault simulation; The fault duration calculation model obtains the action time range and action logic of distance protection, zero-sequence protection or differential protection according to the action characteristics of different types of relay protection devices in the power grid to calculate the fault duration.

[0008] Preferably, the whole process simulation execution unit specifically includes: The initialization subunit is responsible for inputting the parameters of each component in the power system model, including voltage amplitude, phase, load power and initial temperature of the equipment; The fault occurrence subunit establishes a correlation mapping relationship between the power system model's status monitoring data, grid operation parameter change data, and external environment data. When the simulation time reaches the preset fault moment, it obtains data from each data source in real time and makes a comprehensive judgment based on the association rules to determine whether to trigger the fault simulation. The fault development sub-unit divides the power grid model into multiple sub-models based on region, voltage level, and component importance. It sets calculation task allocation rules based on the performance parameters of each computing node. When a fault occurs, the different sub-models are assigned to appropriate computing nodes according to the pre-set task allocation rules to calculate the fault propagation in parallel. The protection action subunit monitors the operating conditions of the power grid in real time. When a fault occurs and the relay protection device is activated, it automatically matches the corresponding protection strategy and adjusts the plan according to the current operating conditions. Specifically: during peak load periods, the protection device's action time limit is extended and its action sensitivity is reduced according to the plan to avoid unnecessary large-scale power outages due to excessive sensitivity; during low load periods, the fault is quickly removed according to the plan.

[0009] Preferably, the power system model building unit specifically includes: Simulate the changes in the electromagnetic characteristics of the transformer during a fault process based on the winding resistance, leakage inductance, magnetizing inductance, and core saturation characteristic parameters; The Bergeron model is used to simulate the transmission line, reflecting the wave process, transient characteristics and distribution of voltage and current along the transmission line; Based on real-time grid operation information, the system automatically matches the corresponding power usage scenario and dynamically adjusts the proportions and parameters of different load types in the load model. The load types include: constant power, constant current, constant impedance, and asynchronous motors. Each power usage scenario includes the power usage characteristics and change patterns of different load types in that scenario. Construct a relay protection device model based on the action logic, setting parameters and hardware characteristics of the actual protection device, including distance protection, zero-sequence protection and differential protection.

[0010] Preferably, the calculation unit is specifically: Establish a power system component importance assessment system, classifying components based on their location in the grid, capacity, and impact on power system stability. Preset smaller grid sizes for critical components. Dynamically adjust the grid based on fault type and propagation direction. Specifically, gradually increase the grid density along the fault propagation path and increase the grid size in areas far from the fault zone where electrical quantities fluctuate more steadily. A layered distributed computing architecture is constructed, dividing computing resources into three tiers: the bottom tier is the local computing nodes, responsible for handling routine, small-scale sub-model computing tasks; the middle tier is the regional computing cluster, composed of multiple local computing nodes, responsible for sub-model computing tasks with moderate computational complexity and frequent data interaction; the top tier is the core computing center, responsible for sub-model computing tasks that involve a large number of complex components and have a large impact on the overall system; A multi-dimensional result verification unit is established, and its specific functions include: verifying the current and voltage results calculated for each simulation step to ensure the conservation of global electrical quantities; comparing and verifying the current simulation results with the key electrical quantity characteristics of similar fault cases in the standard fault case library; the operator manually corrects the auxiliary tools and manually adjusts the parameters in the calculation model.

[0011] Preferably, it also includes a GIS platform module, which is specifically: Collecting geographic information data of the power grid and combining it with the power grid topology data to obtain the action characteristic parameters of all relay protection devices in the power grid, including the action time range, action logic and trip time parameters of various relay protection devices; Building a GIS platform for the power grid, and importing the power grid geographic information data and the power grid topology data into the GIS platform; Deploy a clock synchronization system to accurately calibrate the simulation system time with the clock synchronization system so that the fault is triggered on time at the set microsecond level; Among them, on the GIS platform module, the fault line and the fault occurrence point are determined, and the fault location information is provided to the spatiotemporal parameter setting module.

[0012] Preferably, the multi-dimensional result display unit further includes an export module, which is used to export the data in the simulation process into a standard format file.

[0013] Preferably, in the early stage of a fault, when transient phenomena change dramatically, the simulation step is set to 1 microsecond; when the fault develops and becomes stable, the simulation step is increased to 10 microseconds.

[0014] The present invention has at least the following beneficial effects: 1) The simulation system of the present invention can comprehensively test and verify relay protection equipment without affecting the operation of the actual power system. By simulating various fault scenarios, the simulation system can help users identify potential problems in the design, configuration, and logic of relay protection equipment, thereby improving the reliability and safety of the equipment. Through the simulation system, users can conduct extensive testing and verification in a virtual environment, reducing the risks and costs of conducting experiments in the actual power system. 2) The fault scenario construction unit of the present invention can simulate various faults on transmission lines of different voltage levels and accurately set the time, location, duration, and type of the fault. Therefore, it can simulate various complex fault scenarios that may occur in real power systems, providing a rich experimental environment for testing and verification of relay protection equipment; 3) The power system model building unit of the present invention accurately models the transformer, transmission line, and load models to simulate the dynamic changes in electromagnetic characteristics, the wave process and transient characteristics of the transmission line, and the dynamic changes in the load during a fault. This refined modeling makes the simulation results closer to the actual operation of the power system and can more realistically reflect the distortion of current and voltage at the moment of fault occurrence, thereby improving the accuracy of protection device operation. 4) The calculation unit of the present invention uses a time-domain finite-difference algorithm based on the node voltage method to divide the power system model into discrete networks and discretize time and space. This enables high-precision simulation of the dynamic changes in current and voltage from the moment of fault occurrence to the entire process of fault removal, ensuring the accuracy and reliability of the simulation results. 5) The full-process fault simulation unit of the present invention simulates the entire fault process (initialization, fault occurrence, fault development, and protection action) in stages, showing in detail the entire process from fault occurrence, development to removal, helping users to deeply understand the principles of fault propagation and protection action; 6) In the multi-dimensional result display unit of the present invention, the current and voltage change curve unit displays the current and voltage change curves of each key node during the fault through a visual interface, helping users to intuitively understand the impact of the fault on the power system; the relay protection device working process display unit displays the action sequence, time delay and execution of the working logic of the relay protection device in the form of a timeline, helping users to evaluate the performance and reliability of the relay protection device; the state change display unit displays the state changes of the power grid equipment during the fault process through a 3D model, providing an intuitive and three-dimensional display method to help users better understand the impact of the fault on the power grid equipment.

[0015] Other advantages, objectives and features of the present invention will be reflected in part from the following description and will be understood by those skilled in the art through study and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the relationship structure of the relay protection equipment simulation system based on virtual digitization of the present invention. DETAILED DESCRIPTION

[0017] The present invention will be described in further detail below in conjunction with the accompanying drawings so that those skilled in the art can implement the invention with reference to the description.

[0018] It should be understood that terms such as “having”, “including” and “comprising” used herein do not preclude the existence or addition of one or more other elements or combinations thereof.

[0019] like Figure 1 FIG. 1 is a schematic diagram of the relationship structure of the present invention. The present invention provides a relay protection device simulation system based on virtual digitization, comprising: The fault scenario construction unit is used to simulate various faults of transmission lines of different voltage levels and set the time, location, duration and type of fault.

[0020] The power system model building unit is connected to the fault scenario building unit. The fault scenario building unit provides fault parameters for the power system model building unit. The functions of the power system model building unit include: simulating the dynamic changes of electromagnetic characteristics during the fault period based on the transformer model and its key parameters; simulating the wave process, transient characteristics and distribution law of voltage and current along the transmission line based on the transmission line model and the model reflecting the distributed parameters; simulating the dynamic changes of load under different working conditions based on the load model and various load types; simulating various protection types based on the relay protection device model.

[0021] The calculation unit is connected to the power system model construction unit. The calculation unit divides the power grid of the power system model into discrete networks based on the time-domain finite difference algorithm of the node voltage method, and discretizes time and space to achieve accurate simulation of the dynamic changes of current and voltage from the moment of fault occurrence to the entire process of fault removal.

[0022] The full-process fault simulation unit is connected to the calculation unit and simulates the entire fault process in stages based on the calculation unit's results. Specifically, the full-process fault simulation unit includes: an initialization subunit for initialization; a fault occurrence subunit for simulating the occurrence of a fault when the simulation time reaches the preset fault moment; a fault development subunit for continuously simulating the propagation of the fault in the power grid over time; and a protection action subunit for initiating protection actions according to preset action logic when the relay protection device detects that the fault current exceeds the action threshold. In the early stages of a fault, when transient phenomena change dramatically, the simulation step size is set to 1 microsecond. As the fault develops and stabilizes, the simulation step size is increased to 10 microseconds.

[0023] In the above embodiment, the fault scenario construction unit is mainly used to simulate various faults of transmission lines of different voltage levels and set the key elements of the fault. It can simulate faults that may occur in transmission lines of different voltage levels such as 110kV, 220kV, and 500kV. Set the fault parameters to clarify the specific time when the fault begins, for example, the fault occurs at the 5th second of the simulation; determine the specific location of the line where the fault occurs, such as 30% of the distance from the starting point of the line; set the duration from the occurrence to the end of the fault, such as the fault lasts 0.5 seconds; including common fault types, such as single-phase ground short circuit, two-phase short circuit, two-phase ground short circuit, three-phase short circuit, etc. The power system model construction unit subsequent to the fault scenario construction unit provides accurate fault parameters, so that the entire simulation system can perform more realistic fault simulation based on these parameters.

[0024] The power system model construction unit is connected to the fault scenario construction unit. Based on the fault parameters provided by the fault scenario construction unit, it constructs models of the various components of the power system. Key transformer parameters (such as transformation ratio, winding resistance, and leakage reactance) are used to simulate the dynamic changes in the transformer's electromagnetic characteristics during a fault. When a fault occurs, electromagnetic quantities such as voltage, current, and magnetic flux in the transformer will change, and the transformer model accurately reflects these changes. For the transmission line model, a model that reflects distributed parameters is used to simulate the transmission line. Transmission lines have parameters such as distributed capacitance, inductance, and resistance. This model can better simulate wave processes (such as traveling wave propagation), transient characteristics, and voltage and current distribution patterns along the transmission line. For example, at the moment of a fault, traveling waves propagate along the line, and the transmission line model can simulate traveling wave propagation and reflection phenomena. The load model includes various load types (such as constant impedance loads, constant power loads, and motor loads) to simulate dynamic load changes under different operating conditions. When a fault occurs, the load voltage and current will change, and different load types respond differently to these changes. The load model accurately simulates these dynamic changes. The relay protection device model can simulate various protection types, such as overcurrent protection, overvoltage protection, and differential protection. The relay protection device model can determine whether protective action needs to be triggered based on the power system's operating status and fault conditions. The power system model construction unit constructs a complete power system model, providing the calculation unit with basic data for subsequent fault calculations and simulations. The simulation platform for simulating the power system can be the DDRTS digital-physical hybrid simulation platform or another simulation platform, as long as it can achieve the aforementioned functions.

[0025] The calculation unit is connected to the power system model construction unit and performs calculations based on the time-domain finite difference algorithm of the node voltage method. The power grid of the power system model is divided into discrete networks, and time and space are discretized. For example, the transmission line is divided into several small sections, and time is divided into several small time steps. The discretized model can accurately simulate the dynamic changes of current and voltage from the moment of fault occurrence to the entire process of fault removal. Within each time step, the voltage and current of each node are calculated according to the node voltage method, so as to obtain the changes in current and voltage during the entire fault process. The calculation unit provides accurate current and voltage dynamic change data to the full-process fault simulation unit to simulate the entire fault process.

[0026] For the full-process fault simulation unit, the initialization subunit initializes the entire simulation system and sets initial operating conditions, such as the initial states of each component and the initial voltages and currents of nodes. The fault occurrence subunit simulates the occurrence of a fault when the simulation reaches the preset fault moment. Based on the fault type and location set by the fault scenario construction unit, the corresponding fault conditions are introduced into the power system model. The fault development subunit continuously simulates the propagation of the fault in the power grid over time. Based on the dynamic current and voltage data obtained by the calculation unit, it analyzes how the fault propagates through components such as transmission lines and transformers, as well as its impact on other parts of the power grid. The protection action subunit initiates a protection action based on the preset action logic when the relay protection device model detects that the fault current exceeds the action threshold. For example, if the overcurrent protection detects that the current exceeds the set threshold, it triggers the circuit breaker to trip, disconnecting the faulty line. By simulating the entire fault process in stages, the impact of the fault on the power system and the operation of the relay protection devices are fully demonstrated, providing important reference for power system design, operation, and maintenance.

[0027] In one embodiment, a multi-dimensional result display unit is further included, which includes: The current and voltage change curve unit uses a visual interface to draw the current and voltage change curves of each key node during the fault period, with time as the horizontal axis and current and voltage amplitudes as the vertical axis; The relay protection device working process display unit displays the action sequence, time delay and working logic execution of the relay protection device in the form of a timeline; The state change display unit displays the state changes of power grid equipment during the fault process through a 3D model.

[0028] Specifically, the multi-dimensional result display unit further includes an export module, which is used to export the data in the simulation process into a standard format file.

[0029] In the above-mentioned embodiment, the current and voltage change curve unit presents intuitive curves, enabling rapid identification of abnormal current and voltage fluctuations at key nodes during a fault. For example, when a short circuit occurs on a transmission line, the curves clearly display the sharp rise in current and the significant drop in voltage at the moment of the fault, enabling personnel to accurately determine the time and severity of the fault, enabling rapid repair and restoration of power supply. In complex power systems, the transient process during a fault contains a wealth of information. By comparing and analyzing the change curves at different key nodes, it is possible to deeply understand the patterns of current and voltage changes during the transient process and, in turn, assess the stability of the power system. The relay protection device operation process display unit presents its operation sequence and time delay in the form of a timeline, enabling intuitive verification of whether the protection device is operating correctly according to the preset logic. For example, in a system with a multi-level protection configuration, the timeline clearly displays the sequence of primary and backup protection actions, as well as the time intervals between each action, allowing verification of whether the protection device is experiencing false trips, failed trips, or unreasonable trip times, ensuring that the relay protection device can effectively clear the fault at critical moments and safeguard power system safety. The state change display unit uses 3D models to vividly illustrate the state changes of power grid equipment during a fault. For example, you can visually see the tripping of a circuit breaker on a faulty line or the color change of a transformer's heat sink as the oil temperature rises.

[0030] In one specific implementation, the fault scenario construction unit specifically includes: The fault type generation module uses a deep learning algorithm to analyze a large amount of historical fault data, real-time grid parameters, and power system status monitoring data. By building a fault pattern recognition model, it generates fault types for transmission lines at different voltage levels. The time and space parameter setting module transmits the fault location information determined by the GIS platform to the time and space parameter setting module in real time. The time signal provided by the real-time clock synchronization system is transmitted to the time and space parameter setting module in real time, providing an accurate time reference for the full-process fault simulation unit. The calculation results of the fault duration calculation model are fed back to the time and space parameter setting module, allowing the full-process fault simulation unit to control the duration of the fault simulation. Among them, the fault duration calculation model obtains the action time range and action logic of distance protection, zero-sequence protection or differential protection according to the action characteristics of different types of relay protection devices in the power grid to calculate the fault duration.

[0031] Among them, it also includes the GIS platform module, whose specific functions are: Collect geographic information data of the power grid and combine it with the power grid topology data to obtain the action characteristic parameters of all relay protection devices in the power grid. The action characteristic parameters include the action time range and action logic of various relay protection devices and the trip time parameters of circuit breakers. The construction process is as follows: Build a GIS platform for the power grid and import the power grid geographic information data and power grid topology data into the GIS platform; Deploy a clock synchronization system to accurately calibrate the simulation system time with the clock synchronization system so that the fault is triggered on time at the set microsecond level; Among them, on the GIS platform module, the fault line and the fault occurrence point are determined to provide fault location information for the spatiotemporal parameter setting module.

[0032] In the above-described embodiment, various fault records accumulated over a long period of time during power system operation are collected, including information on faults occurring at different voltage levels (e.g., 110kV, 220kV, 500kV, etc.), at different times, and in different geographical locations. For example, details of faults such as short circuits and open circuits on different transmission lines over the past few years are collected, including the time and location of the faults, as well as the operating status of the power grid before the faults, such as node voltages, line currents, and power distribution. This data forms the basis for deep learning algorithms to mine fault patterns. Specifically, deep learning algorithms can employ recurrent neural networks. Current power system operating parameters are collected in real time, such as the voltage amplitude and phase at each node, which reflect the magnitude and angle of the node voltage; and the magnitude and direction of the current in the line, which can intuitively demonstrate the flow of current in the transmission line. By acquiring these parameters in real time, the model can understand the current operating status of the power grid and accurately predict the type of fault. Various sensors and monitoring devices collect power system equipment status information, such as transformer oil and winding temperatures. Excessively high oil temperatures may indicate an internal transformer overheating fault; abnormal gas content in the oil may indicate insulation damage within the transformer; transmission line sag and conductor temperature. Sag variations may affect line safety distances, while excessively high conductor temperatures may be caused by overloads; and insulator leakage current. Abnormal leakage current may indicate degraded insulator performance. This data can help identify potential equipment failures and provide important evidence for fault type prediction. Deep learning algorithms are used to analyze and process massive amounts of data. Deep learning algorithms have powerful feature extraction and pattern recognition capabilities, enabling them to uncover hidden patterns and patterns in complex data. By building a fault pattern recognition model, the model learns the mapping between different fault types and various data types. For example, if the model learns that under a specific combination of grid parameters, abnormal changes in certain equipment status monitoring data may indicate a high probability of a certain type of short-circuit fault. If similar data features appear in subsequent operation, the model can accurately predict the likely fault type, providing a foundation for fault simulation.

[0033] The GIS platform monitors the geographic location of transmission lines in real time and, by linking it with the power system model, identifies the likely location of faults. When a monitoring point on a transmission line detects an abnormal signal, the GIS platform quickly locates the point's specific location on the line and transmits this information in real time to the spatiotemporal parameter setting module. This allows fault simulations to be carried out at specific locations, more realistically reflecting actual conditions. The real-time clock synchronization system provides a high-precision time signal to ensure time synchronization within the power system. The spatiotemporal parameter setting module receives this signal and provides a unified and accurate starting point for all fault simulation units. During fault simulation, the fault occurrence time and the duration of each phase are accurately referenced, facilitating analysis of the fault's impact on the power system at different moments. The fault duration calculation model calculates fault duration based on the operating characteristics of different types of relay protection devices in the power grid. Different types of relay protection devices, such as distance protection, zero-sequence protection, and differential protection, each have specific operating time ranges. Distance protection is commonly used to respond to phase-to-phase short-circuit faults on transmission lines. Its operating time depends on the distance from the fault point to the protection installation and the protection setting range. Zero-sequence protection primarily responds to ground faults and also has a corresponding operating time setting. The fault duration calculation model captures the time ranges within which these protection devices operate, providing the fundamental data for calculating the fault duration. In addition to the time ranges, the protection device's operating logic is also factored into the calculations. In a multi-level protection configuration, the primary protection device operates first. If the primary protection device refuses to operate, the backup protection device operates. The fault duration calculation model analyzes this operating logic to determine the time required from fault occurrence to fault clearance by the protection device under different fault scenarios. The calculation results are fed back to the spatiotemporal parameter setting module, enabling the full-process fault simulation unit to precisely control the fault simulation duration and realistically simulate the entire process from fault occurrence to fault clearance.

[0034] The GIS platform module collects geographic information about the area covered by the power grid, including topography, building distribution, and transportation routes. This geographic information is crucial for understanding the environment surrounding transmission lines and analyzing how environmental factors may influence faults. For example, transmission lines in mountainous areas may be more susceptible to failure due to severe weather, landslides, and other geological hazards. Grid topology data describes the connections between various components in the power system (such as generators, transformers, transmission lines, and loads). Combining geographic information with grid topology data allows for a visual representation of the grid layout in geographic space. Furthermore, the operating characteristic parameters of all relay protection devices in the grid can be obtained, including the operating time ranges of various relay protection devices, such as the operating time settings for distance protection stages I, II, and III; the operating logic, such as the coordination logic between primary and backup protection; and the tripping time parameters of circuit breakers. These parameters are crucial for accurately simulating fault processes and protective device operation. Importing the collected power grid geographic information and topology data into a purpose-built power grid GIS platform module enables intuitive mapping of the power grid's distribution, clearly showing the routing of transmission lines, the location of substations, and the geographic relationships of various power equipment. This not only facilitates daily management and maintenance of the power grid but also provides a visual foundation for fault scenario construction. A high-precision clock synchronization system is deployed, and the simulation system time is precisely aligned with the clock synchronization system. This ensures that faults are triggered precisely at the microsecond-level in fault scenario construction. In power system simulation, time accuracy is critical for simulating the instant of fault occurrence and the temporal sequence of subsequent stages, ensuring that simulation results more closely align with the temporal characteristics of actual power system faults. The GIS platform module leverages its powerful spatial analysis capabilities, combined with the power grid topology and real-time monitoring data, to identify the fault line and fault location. For example, when abnormal changes in the current and voltage of a transmission line are monitored, the GIS platform module can quickly locate the specific fault line and fault location through analysis, and transmit this fault location information to the spatiotemporal parameter setting module in real time, providing key information for the accurate construction of the fault scenario.

[0035] In one specific embodiment, the whole process simulation execution unit specifically includes: The initialization subunit is responsible for inputting the parameters of each component in the power system model, including voltage amplitude, phase, load power and initial temperature of the equipment; The fault occurrence subunit establishes a correlation mapping relationship between the power system model's status monitoring data, grid operation parameter change data, and external environment data. When the simulation time reaches the preset fault moment, it obtains data from each data source in real time and makes a comprehensive judgment based on the association rules to determine whether to trigger the fault simulation. The fault development sub-unit divides the power grid model into multiple sub-models based on region, voltage level, and component importance. It sets calculation task allocation rules based on the performance parameters of each computing node. When a fault occurs, the different sub-models are assigned to appropriate computing nodes according to the pre-set task allocation rules to calculate the fault propagation in parallel. The protection action subunit monitors the operating conditions of the power grid in real time. When a fault occurs and the relay protection device is activated, it automatically matches the corresponding protection strategy and adjusts the plan according to the current operating conditions. Specifically: during peak load periods, the protection device's action time limit is extended and its action sensitivity is reduced according to the plan to avoid unnecessary large-scale power outages due to excessive sensitivity; during low load periods, the fault is quickly removed according to the plan.

[0036] In the above-described embodiment, the fault occurrence subunit establishes a correlation mapping relationship between the power system model's state monitoring data, grid operating parameter change data, and external environment data. When the simulation reaches the preset fault time, data from each data source is acquired in real time and, based on correlation rules, a comprehensive determination is made as to whether to trigger the fault simulation. This multi-source data fusion and correlation analysis approach more realistically simulates the situation in which power systems are affected by multiple factors during actual operation and cause faults. Compared to single-data determination, this significantly improves the accuracy and reliability of fault trigger determination, reduces the likelihood of misjudgments and missed detections, and makes the fault simulation more realistic, providing a more accurate starting point for subsequent research on fault response strategies. The fault development subunit divides the power grid model into multiple submodels based on region, voltage level, and component importance. It also sets computational task allocation rules based on the performance parameters of each compute node. For example, submodels with high complexity and high computational requirements, such as submodels for high-voltage grid regions containing a large number of components, are preferentially assigned to compute nodes with strong computing capabilities (e.g., fast CPU speed and large memory capacity). After a fault occurs, the different submodels are assigned to appropriate compute nodes according to pre-defined rules to perform parallel computations on the fault propagation. This parallel computing approach significantly improves the efficiency of fault propagation analysis, especially in the simulation of large-scale, complex power grid models. By fully utilizing computing resources, simulation time is shortened, enabling faster acquisition of detailed information about fault development and timely development of effective fault response measures, thereby enhancing the power system's emergency response capabilities in the event of a fault. The protection action subunit monitors the grid's operating conditions in real time. When a fault occurs and the relay protection device activates, it automatically adapts the protection strategy to the current operating conditions. During peak load periods, the protection device's action time is appropriately extended and its sensitivity is reduced to avoid unnecessary, large-scale power outages caused by excessive sensitivity, ensuring the power system's ability to maintain continuous power supply under high load demands. During low load periods, the fault is quickly cleared according to the plan to prevent further damage to the power system. This adaptive protection strategy adjustment mechanism flexibly optimizes the operation of relay protection devices based on the characteristics of the power system's varying operating conditions, improving the reliability and stability of the power system under various circumstances and reducing power outages and economic losses caused by improper protection.

[0037] In one specific implementation, the power system model building unit specifically includes: Simulate the changes in the electromagnetic characteristics of the transformer during a fault process based on the winding resistance, leakage inductance, magnetizing inductance, and core saturation characteristic parameters; The Bergeron model is used to simulate the transmission line, reflecting the wave process, transient characteristics and distribution of voltage and current along the transmission line; Based on real-time grid operation information, the system automatically matches the corresponding power usage scenario and dynamically adjusts the proportions and parameters of different load types in the load model. Load types include: constant power, constant current, constant impedance, and asynchronous motors. Each power usage scenario includes the power usage characteristics and change patterns of different load types in that scenario. The relay protection device model is constructed based on the action logic, setting parameters and hardware characteristics of the actual protection device, including distance protection, zero-sequence protection and differential protection.

[0038] In the above-described embodiment, winding resistance, leakage inductance, magnetizing inductance, and core saturation parameters are key factors in describing the electromagnetic characteristics of the transformer. Winding resistance determines the energy loss when current passes through the windings, leakage inductance affects the electromagnetic coupling between transformer windings, magnetizing inductance is related to the transformer's magnetizing current, and core saturation parameters reflect the core's magnetization characteristics under varying magnetic field intensities. During a fault, these parameters can change, affecting the transformer's electromagnetic characteristics. For example, when a short-circuit fault occurs, the winding current increases dramatically, generating increased heat in the winding resistance, potentially causing a change in resistance. Simultaneously, the strong magnetic field generated by the short-circuit current can saturate the core, changing the magnetizing inductance and core saturation parameters. By accurately simulating the changes in these parameters, the electromagnetic characteristics of the transformer during a fault, such as voltage distortion and current imbalance, can be accurately reflected. Based on real-time grid operating information, such as voltage, frequency, and power, the system can automatically adapt to the corresponding power usage scenario. Different power usage scenarios, such as industrial, residential, and commercial, have different power usage characteristics and changing patterns. Based on the matching results of power usage scenarios, the proportions and parameters of different load types (constant power, constant current, constant impedance, and asynchronous motors) in the load model are dynamically adjusted. For example, during peak residential electricity usage periods, the proportion of constant power loads may increase. In this case, the parameters of the constant power load model need to be adjusted accordingly to accurately reflect its power usage characteristics in this scenario. Through this dynamic adjustment, the load model can more realistically simulate the changes in load under different power usage scenarios, improving the accuracy of power system simulation. The Bergeron model is a model widely used in transmission line simulation. Based on traveling wave theory, it can accurately reflect the wave process of transmission lines. During transmission line operation, when faults or interference occur, traveling waves are generated. Traveling waves propagate along the transmission line and cause reflection and refraction.

[0039] In one specific embodiment, the computing unit is: Based on the establishment of a power system component importance assessment system, components are graded according to their location in the power grid, capacity, and the degree of impact on the stability of the power system. For key components, a smaller grid size is pre-set; according to the fault type and propagation direction, the grid division is dynamically adjusted. Specifically, on the fault propagation path, the grid is gradually encrypted, and in areas far away from the fault area and where the electrical quantity changes are stable, the grid size is increased.

[0040] The importance of components is divided into the following categories, in the form of scores: 1) Grid Topology Location: Components located at core grid hubs (e.g., regional interconnection stations, intersections of multiple circuits) are scored based on the number of circuits. Two intersections are scored as 2 points, while no intersections are scored as 1 point.

[0041] 2) Equipment capacity and functions Large-capacity equipment: high-capacity generators, trunk transmission lines (e.g., 500kV / 220kV), large-capacity transformers, etc., whose failures may cause power imbalance in the entire network and are therefore of high importance; scored 3 points Key functional equipment: system stability control devices, starting power supplies, etc., which directly affect the system's recovery capability and are scored 2 points.

[0042] The remaining equipment is scored as 1 point.

[0043] 3) Impact on system stability Components that may cause cascading tripping after removal (such as lines on important transmission sections) require the highest priority protection and are scored 3 points.

[0044] Reactive power compensation equipment (e.g., SVG, capacitor banks) that affects voltage stability, or large generators that support system frequency; 2 points.

[0045] The remaining equipment is scored as 1 point.

[0046] Among them, the stable change of electrical quantity refers to the following indicators: 1) Amplitude fluctuation rate (voltage or current), for example, fluctuation within a 10ms window is less than 0.5% (high voltage network) or 1% (medium voltage network) of the rated value; 2) Continuous stability duration, for example, the state is maintained continuously for ≥ 30 μs, 3 simulation steps.

[0047] A layered distributed computing architecture is constructed, dividing computing resources into three tiers: the bottom tier is the local computing nodes, responsible for handling routine, small-scale sub-model computing tasks; the middle tier is the regional computing cluster, composed of multiple local computing nodes, responsible for sub-model computing tasks with moderate computational complexity and frequent data interaction; the top tier is the core computing center, responsible for sub-model computing tasks that involve a large number of complex components and have a large impact on the overall system; Establish a multi-dimensional result verification unit, including: verifying the current and voltage results calculated for each simulation step to ensure the conservation of global electrical quantities; comparing and verifying the current simulation results with the key electrical quantity characteristics of similar fault cases in the standard fault case library; operators manually correct auxiliary tools and manually adjust the parameters in the calculation model.

[0048] In the above-described implementation, by establishing a power system component importance assessment system, components are graded based on location, capacity, and impact on system stability, and smaller grid sizes are pre-set for key components. This significantly improves the computational accuracy of key component fault simulations. For example, a transformer in a hub substation is a key component. Using a small grid size allows for more detailed simulation of its internal electromagnetic transients, capturing small but potentially significant changes in electrical quantities that can have a significant impact on the system. This ensures accurate assessment of the impact of key component failures on the system and avoids misjudgments of key component failures due to insufficient computational accuracy. Dynamically adjusting the grid based on fault type and propagation direction, gradually increasing the grid density along the fault propagation path, accurately captures rapid changes in electrical quantities during fault propagation and ensures accurate calculation of critical fault development areas. Increasing the grid size in areas away from the fault zone where electrical quantities change more steadily reduces unnecessary computational effort and avoids resource waste. This dynamic grid division strategy significantly improves overall computational efficiency while ensuring computational accuracy, shortens fault simulation time, and enables a more comprehensive picture of fault development, enabling timely response measures. A hierarchical distributed computing architecture is constructed, dividing computing resources into three levels: local computing nodes, regional computing clusters, and core computing centers, achieving a precise match between computing tasks and computing resources. A multi-dimensional result verification unit verifies the current and voltage results calculated for each simulation step to ensure the conservation of global electrical quantities, which is key to ensuring the accuracy of calculation results. The conservation of electrical quantities is a fundamental physical law of power system operation. Through verification, errors or deviations in the calculation process can be promptly discovered, such as non-conservation of electrical quantities caused by numerical calculation errors, thereby ensuring that the simulation results conform to actual physical principles.

[0049] The number of devices and processing scales described herein are intended to simplify the description of the present invention. Applications, modifications, and variations of the present invention will be readily apparent to those skilled in the art.

[0050] Although the embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the description and implementation methods. They can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to the specific details and illustrations shown and described herein.

Claims

1. The relay protection equipment simulation system based on virtual digitalization is characterized by: It includes a fault scenario construction unit, a power system model construction unit, a calculation unit and a full-process fault simulation unit connected in sequence; The fault scenario construction unit is used to simulate faults on transmission lines of different voltage levels and set the time, location, duration and type of the fault; it provides fault parameters to the power system model construction unit; The power system model building unit simulates the dynamic changes of electromagnetic characteristics during a fault based on the transformer model and its parameters; simulates the wave process, transient characteristics and distribution law of voltage and current along the transmission line based on the transmission line model and the model reflecting the distributed parameters; and simulates the dynamic changes of load under different working conditions based on the load model and various load types. Simulate various relay protection types based on relay protection device models; The computing unit divides the power grid of the power system model into discrete networks based on the time-domain finite-difference algorithm of the node voltage method, and discretizes time and space to accurately simulate the dynamic changes of current and voltage from the moment of fault occurrence to the entire process of fault removal; The whole process fault simulation unit simulates the whole process of fault occurrence in stages according to the result of the calculation unit.

2. The relay protection device simulation system based on virtual digitalization according to claim 1, characterized in that: It also includes a multi-dimensional result display unit, which includes a current and voltage change curve unit, a relay protection device working process display unit and a state change display unit; The current and voltage change curve unit draws the current and voltage change curve of the node during the fault period through a visual interface, with time as the horizontal axis and current and voltage amplitudes as the vertical axis; The relay protection device working process display unit displays the action sequence, time delay and working logic execution of the relay protection device in the form of a time axis; The state change display unit displays the state changes of the power grid equipment during the fault process through a 3D model.

3. The relay protection device simulation system based on virtual digitalization according to claim 2, characterized in that: The system also includes a GIS platform module, which is used to collect geographic information data of the power grid and, in combination with the power grid topology data, obtain the action characteristic parameters of all relay protection devices in the power grid. The fault line and the fault occurrence point are determined on the GIS platform module, providing fault location information for the spatiotemporal parameter setting module in the fault scenario construction unit. The action characteristic parameters include the action time range and action logic of various relay protection devices and the trip time parameters of the circuit breaker. The construction process is as follows: 1) Build a GIS platform for the power grid and import the power grid geographic information data and power grid topology data into the GIS platform; 2) Deploy a clock synchronization system and calibrate the simulation system time with the clock synchronization system so that the fault is triggered on time at the set microsecond level.

4. The relay protection device simulation system based on virtual digitalization according to claim 1, characterized in that: The fault scenario construction unit includes a fault type generation module and a time and space parameter setting module; The fault type generation module uses a deep learning algorithm to analyze historical fault data, real-time grid parameters, and power system status monitoring data, and generates fault types for transmission lines of different voltage levels by building a fault pattern recognition model; The spatiotemporal parameter setting module receives in real time the fault location information determined by the GIS platform, the time signal provided by the real-time clock synchronization system, and the calculation result of the fault duration calculation model, provides a time reference for the full-process fault simulation unit, and controls the duration of the fault simulation through the full-process fault simulation unit; The fault duration calculation model obtains the action time range and action logic of distance protection, zero-sequence protection or differential protection according to the action characteristics of different types of relay protection devices in the power grid to calculate the fault duration.

5. The relay protection equipment simulation system based on virtual digitization according to claim 1, characterized in that: The full-process simulation execution unit includes an initialization subunit, a fault occurrence subunit, a fault development subunit and a protection action subunit; The initialization subunit is used to input parameters of each component in the power system model, including voltage amplitude, phase, load power and initial temperature of the equipment; The fault occurrence subunit is used to establish an associated mapping relationship between the state monitoring data of the power system model, the grid operation parameter change data, and the external environment data. When the simulation time reaches the preset fault time, the data from each data source is obtained in real time, and a comprehensive judgment is made based on the association rules to determine whether to trigger the fault simulation; The fault development sub-unit divides the power grid model into multiple sub-models based on regions, voltage levels, and component importance. It sets calculation task allocation rules based on the performance parameters of each computing node. When a fault occurs, the different sub-models are assigned to appropriate computing nodes according to the pre-set task allocation rules to parallelly calculate the fault propagation. The protection action subunit monitors the operating conditions of the power grid in real time. When a fault occurs and the relay protection device is activated, it automatically matches the corresponding protection strategy adjustment plan according to the current operating conditions. Specifically, during peak load periods, the action time limit of the protection device is extended and the action sensitivity is reduced to avoid large-scale power outages caused by excessive sensitivity; during low load periods, the fault is quickly removed.

6. The relay protection equipment simulation system based on virtual digitalization according to claim 1, characterized in that: The specific functions of the power system model building unit are as follows: 1) Simulate the changes in the electromagnetic characteristics of the transformer during a fault process based on the winding resistance, leakage inductance, magnetizing inductance, and core saturation characteristic parameters; 2) Use the Bergeron model to simulate transmission lines, reflecting the wave process, transient characteristics, and distribution of voltage and current along the transmission lines; 3) Automatically match corresponding power usage scenarios based on real-time grid operation information and dynamically adjust the proportions and parameters of different load types in the load model. The load types include: constant power, constant current, constant impedance, and asynchronous motors. Each power usage scenario includes the power usage characteristics and change patterns of different load types in that scenario. 4) Construct a relay protection device model based on the actual protection device's action logic, set parameters and hardware characteristics.

7. The relay protection equipment simulation system based on virtual digitization according to claim 5, characterized in that: The specific functions of the calculation unit are as follows: 1) Establish a power system component importance assessment system: Components are classified based on their location in the grid, capacity, and impact on power system stability, and the grid size of the components is pre-set. The grid division is dynamically adjusted based on the fault type and propagation direction. Specifically, the grid is gradually denser along the fault propagation path, and the grid size is increased in areas far from the fault area where electrical quantity changes are stable. 2) Build a hierarchical distributed computing architecture: Divide computing resources into different layers to calculate sub-model computing tasks of different complexities; 3) Establish a multi-dimensional result verification unit: verify the current and voltage results calculated for each simulation step to ensure the conservation of global electrical quantities; compare and verify the current simulation results with the electrical quantity characteristics of the fault cases in the standard fault case library.

8. The relay protection equipment simulation system based on virtual digitization according to claim 3 is characterized in that: The multi-dimensional result display unit further includes an export module, which is used to export the data in the simulation process into a standard format file.

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