Virtual digital based relay protection device simulation system

Abstract

This invention discloses a virtual digital relay protection equipment simulation system, comprising: a fault scenario construction unit, used to simulate various faults and set the time, location, duration, and type of fault occurrence; a power system model construction unit, comprising: using a transformer model to simulate the dynamic changes of electromagnetic characteristics during fault occurrence; using a transmission line model to simulate the wave process, transient characteristics, and voltage and current distribution along the transmission line; and using a load model to simulate the dynamic changes of the load; a calculation unit, which, based on the nodal voltage method and the finite-difference time-domain algorithm, divides the power grid into discrete networks and discretizes time and space; and a full-process fault simulation unit, which simulates the entire fault occurrence process in stages. This system provides a comprehensive, accurate, and dynamic simulation environment for relay protection equipment testing and power system fault analysis, thereby improving the safety and reliability of the power system.

Description

Technical Field

[0001] This invention relates to the field of power system simulation. More specifically, this invention relates to a virtual digital relay protection equipment simulation system. Background Technology

[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, and its performance directly impacts the reliability of the power grid. However, existing relay protection equipment simulation systems face numerous technical challenges in practical applications. Traditional simulation methods often employ simplified models when dealing with components such as transformers and transmission lines. This results in simulations that fail to accurately reflect the distortion of current and voltage at the moment of a fault, thus affecting the accuracy of the protection device's operation. Existing protection logic is mostly designed based on offline threshold settings. Under complex operating conditions, this can easily lead to maloperation or failure to operate, reducing the reliability of the power grid. As the scale and complexity of the power grid continue to expand, traditional centralized computing architectures are struggling to handle massive amounts of data. This is especially true when simulating multiple fault propagation paths, where slow computation speed and high resource consumption become even more pronounced, making it difficult to meet the demands of real-time simulation. Summary of the Invention

[0003] This invention provides a virtual digital relay protection equipment simulation system, which provides a comprehensive, accurate and dynamic simulation environment for relay protection equipment testing and power system fault analysis, thereby improving the safety and reliability of the power system.

[0004] To achieve these objectives and other advantages of the present invention, a virtual digital relay protection equipment simulation system is provided, comprising:

[0005] The fault scenario construction unit is used to simulate various faults in transmission lines of different voltage levels, and to set the time, location, duration and type of the fault.

[0006] A power system model building unit, connected to the fault scenario building unit, provides fault parameters to the power system model building unit. The power system model building unit includes: simulating the dynamic changes of electromagnetic characteristics during a fault using a transformer model and its key parameters; simulating the wave process, transient characteristics, and voltage and current distribution patterns along a transmission line using a transmission line model and a model reflecting distributed parameters; simulating the dynamic changes of load under different operating conditions using a load model and various load types; and simulating various protection types using a relay protection device model.

[0007] The calculation unit is connected to the power system model construction unit. The calculation unit is based on the time-domain finite difference algorithm of the nodal voltage method. It divides the power grid of the power system model into discrete networks 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 clearing.

[0008] A full-process fault simulation unit is connected to the calculation unit and simulates the entire fault occurrence process in stages based on the results of the calculation unit.

[0009] Preferably, the full-process fault simulation unit specifically includes: an initialization subunit for initializing operation; a fault occurrence subunit for simulating the occurrence of a fault when the simulation time reaches a preset fault moment; a fault development subunit for continuously simulating the propagation process of the fault in the power grid over time; and a protection action subunit for issuing a protection action according to a preset action logic when the relay protection device detects that the fault current exceeds the action threshold.

[0010] Preferably, it also includes a multi-dimensional result display unit, which includes:

[0011] The current and voltage change curve unit uses a visual interface to plot the current and voltage change curves of each key node during the fault, with time as the horizontal axis and current and voltage amplitude as the vertical axis.

[0012] The relay protection device operation process display unit shows the action sequence, time delay, and execution of the working logic of the relay protection device in the form of a timeline.

[0013] The status change display unit uses a 3D model to show the status changes of power grid equipment during a fault process.

[0014] Preferably, the fault scenario construction unit specifically includes:

[0015] The fault type generation module uses deep learning algorithms to analyze a large amount of historical fault data, real-time power grid parameters, and power system status monitoring data. By constructing a fault mode recognition model, it generates fault types for transmission lines of different voltage levels.

[0016] The spatiotemporal parameter setting module receives fault location information determined by the GIS platform in real time; the time signal provided by the real-time clock synchronization system is also transmitted to the spatiotemporal 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 spatiotemporal parameter setting module, enabling the full-process fault simulation unit to control the duration of the fault simulation.

[0017] The fault duration calculation model calculates the fault duration by obtaining the operating time range and operating logic of distance protection, zero-sequence protection or differential protection based on the operating characteristics of different types of relay protection devices in the power grid.

[0018] Preferably, the full-process simulation execution unit specifically includes:

[0019] The initialization subunit is responsible for inputting parameters of each component in the power system model, including voltage amplitude, phase, load power, and initial equipment temperature.

[0020] The fault occurrence subunit establishes the correlation mapping relationship between the power system model's state monitoring data, power grid operating parameter change data, and external environment data. When the simulation time reaches the preset fault time, it acquires data from each data source in real time and makes a comprehensive judgment based on the correlation rules to determine whether to trigger the fault simulation.

[0021] The fault propagation subunit divides the power grid model into multiple sub-models based on region, voltage level, and component importance. Based on the performance parameters of each computing node, computing task allocation rules are set. When a fault occurs, different sub-models are assigned to appropriate computing nodes to perform parallel fault propagation calculations according to the pre-set task allocation rules.

[0022] The protection action subunit monitors the power grid operation status in real time. When a fault occurs and the relay protection device is activated, it automatically matches the corresponding protection strategy and adjusts the contingency 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 according to the contingency plan to avoid unnecessary large-scale power outages due to excessive sensitivity; during off-peak load periods, the fault is quickly cleared according to the contingency plan.

[0023] Preferably, the power system model building unit specifically includes:

[0024] Based on the parameters of winding resistance, leakage inductance, magnetizing inductance, and core saturation characteristics, the electromagnetic characteristic changes of the transformer during the fault process are simulated.

[0025] The Bergeron model is used to simulate the transmission line, reflecting the wave process, transient characteristics, and voltage and current distribution along the line.

[0026] Based on real-time power grid operation information, the system automatically matches the corresponding power consumption scenarios 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 consumption scenario includes the power consumption characteristics and variation patterns of different load types in that scenario.

[0027] Based on the actual operating logic, setting parameters, and hardware characteristics of the protection device, a relay protection device model is constructed, including distance protection, zero-sequence protection, and differential protection.

[0028] Preferably, the computing unit specifically comprises:

[0029] Establish a power system component importance assessment system. Components are classified according to their location in the power grid, capacity, and impact on power system stability. For critical components, a smaller grid size is pre-set. The grid division is dynamically adjusted according to the fault type and propagation direction. Specifically, the grid is gradually densified along the fault propagation path, and the grid size is increased in areas far from the fault area and where electrical quantities change steadily.

[0030] A layered distributed computing architecture is constructed, dividing computing resources into three layers: the bottom layer consists of local computing nodes, which are responsible for handling routine sub-model computing tasks with small computational loads; the middle layer consists of regional computing clusters, which are composed of multiple local computing nodes and are responsible for sub-model computing tasks with moderate computational complexity and frequent data interaction; the top layer consists of the core computing center, which is responsible for sub-model computing tasks that contain a large number of complex components and have a significant impact on the overall system.

[0031] A multi-dimensional result verification unit is established, with specific functions including: verifying the current and voltage results calculated at each simulation step to ensure the conservation of global electrical quantities; comparing and verifying the key electrical quantity characteristics of the current simulation results with similar fault cases in the standard fault case library; and providing an auxiliary tool for manual correction by operators, allowing operators to manually adjust the parameters in the calculation model.

[0032] Preferably, it also includes a GIS platform module, which specifically includes:

[0033] Geographic information data of the power grid is collected and combined with power grid topology data to obtain the operating characteristic parameters of all relay protection devices in the power grid. The operating characteristic parameters include the operating time range, operating logic of various relay protection devices, and tripping time parameters of circuit breakers.

[0034] Construct a GIS platform for the power grid and import the power grid geographic information data and power grid topology data into the power grid GIS platform;

[0035] Deploy a clock synchronization system to precisely calibrate the simulation system's time with the clock synchronization system, so that the fault is triggered precisely at the set microsecond level.

[0036] Specifically, the GIS platform module identifies the faulty line and the fault location, providing fault location information to the spatiotemporal parameter setting module.

[0037] Preferably, the multi-dimensional result display unit also includes an export module, which is used to export the data from the simulation process into a standard format file.

[0038] Preferably, in the early stage of a fault, when the transient phenomenon changes drastically, the simulation step size is set to 1 microsecond; when the fault development tends to stabilize, the simulation step size is increased to 10 microseconds.

[0039] The present invention has at least the following beneficial effects:

[0040] 1) The simulation system of this invention can perform comprehensive testing and verification of relay protection equipment without affecting the actual operation of the power system; by simulating various fault scenarios, the simulation system can help users discover 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 a large number of tests and verifications in a virtual environment, reducing the risks and costs of conducting tests in the actual power system;

[0041] 2) The fault scenario construction unit of this invention can simulate various faults of transmission lines with 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 the testing and verification of relay protection equipment.

[0042] 3) The power system model building unit of this invention can simulate the dynamic changes of electromagnetic characteristics, the wave process and transient characteristics of transmission lines, and the dynamic changes of loads during the occurrence of faults by accurately modeling transformers, transmission lines and loads. This refined modeling can make 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 the protection device operation.

[0043] 4) The computing unit of this invention adopts the time-domain finite difference algorithm based on the nodal voltage method, which divides the power system model into discrete networks and discretizes time and space. This enables high-precision simulation of the dynamic changes of current and voltage from the moment a fault occurs to the moment it is cleared, ensuring the accuracy and reliability of the simulation results.

[0044] 5) The full-process fault simulation unit of this invention simulates the entire process of fault occurrence (initialization, fault occurrence, fault development, and protection action) in stages, which can show the entire process of fault occurrence, development and isolation in detail, helping users to deeply understand the principles of fault propagation and protection action;

[0045] 6) In the multi-dimensional result display unit of this 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 working logic of the relay protection device in the form of a time axis, helping users to evaluate the performance and reliability of the relay protection device; the state change display unit displays the state changes of 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.

[0046] Other advantages, objectives and features of the present invention will become apparent in part from the following description, and in part from those skilled in the art through study and practice of the invention. Attached Figure Description

[0047] Figure 1 This is a schematic diagram of the relational structure of the virtual digital relay protection equipment simulation system of the present invention. Detailed Implementation

[0048] The present invention will now be described in further detail with reference to the accompanying drawings, so that those skilled in the art can implement it based on the description.

[0049] It should be understood that terms such as “having,” “comprising,” and “including” as used herein do not exclude the presence or addition of one or more other elements or combinations thereof.

[0050] like Figure 1 The diagram shown illustrates the relational structure of this invention. This invention provides a virtual digital relay protection equipment simulation system, comprising:

[0051] The fault scenario construction unit is used to simulate various faults in transmission lines of different voltage levels, and to set the time, location, duration, and type of fault occurrence.

[0052] The power system model building unit is connected to the fault scenario building unit. The fault scenario building unit provides fault parameters to the power system model building unit. The functions of the power system model building unit include: simulating the dynamic changes of electromagnetic characteristics during a fault based on the transformer model and its key parameters; simulating the wave process, transient characteristics, and voltage and current distribution patterns along the transmission line based on the transmission line model and the model reflecting distributed parameters; simulating the dynamic changes of the load under different operating conditions based on the load model and various load types; and simulating various protection types based on the relay protection device model.

[0053] The calculation unit is connected to the power system model construction unit. Based on the nodal voltage method, the calculation unit divides the power grid of the power system model into discrete networks and discretizes time and space to achieve accurate simulation of the dynamic changes of current and voltage from the moment a fault occurs to the moment it is cleared.

[0054] The full-process fault simulation unit, connected to the calculation unit, simulates the entire fault occurrence process in stages based on the results of the calculation unit. Specifically, the full-process fault simulation unit includes: an initialization subunit for initializing operation; a fault occurrence subunit for simulating the occurrence of a fault at a preset fault time; a fault development subunit for continuously simulating the propagation process of the fault in the power grid over time; and a protection action subunit for issuing protection actions according to preset action logic when the relay protection device detects a fault current exceeding the action threshold. In the early stages of fault occurrence, transient phenomena change drastically, so the simulation step size is set to 1 microsecond; as the fault development stabilizes, the simulation step size is increased to 10 microseconds.

[0055] In the above embodiments, the fault scenario construction unit is mainly used to simulate various faults on transmission lines of different voltage levels and to set the key elements of the fault. It can simulate faults that may occur on transmission lines of different voltage levels, such as 110kV, 220kV, and 500kV. Fault parameters are set, specifying the exact time the fault begins, for example, the fault occurring at the 5th second of the simulation; determining the specific location of the fault on the line, such as 30% from the start of the line; setting the duration of the fault from occurrence to end, for example, the fault lasting 0.5 seconds; and including common fault types, such as single-phase-to-ground short circuit, two-phase short circuit, two-phase-to-ground short circuit, and three-phase short circuit. The subsequent power system model construction unit of the fault scenario construction unit provides accurate fault parameters, enabling the entire simulation system to perform more realistic fault simulations based on these parameters.

[0056] The power system model building unit is connected to the fault scenario building unit. Based on the fault parameters provided by the fault scenario building unit, models of various components of the power system are constructed. Key transformer parameters (such as turns ratio, winding resistance, and leakage reactance) are used to simulate the dynamic changes in the electromagnetic characteristics of the transformer during a fault. When a fault occurs, electromagnetic quantities such as voltage, current, and magnetic flux of the transformer change, and the transformer model accurately reflects these changes. For the transmission line model, a model reflecting distributed parameters is used to simulate the transmission line. Transmission lines have parameters such as distributed capacitance, inductance, and resistance. The transmission line model can better simulate the wave processes (such as traveling wave propagation), transient characteristics, and the distribution patterns of voltage and current along the line. For example, at the instant a fault occurs, traveling waves propagate along the line, and the transmission line model can simulate the propagation process and reflection phenomena of traveling waves. For the load model, various load types are included (such as constant impedance loads, constant power loads, and motor loads), which can simulate the dynamic changes of the load under different operating conditions. When a fault occurs, the voltage and current of the load change, and different types of loads respond differently to these changes; the load model can accurately simulate this dynamic change. The relay protection device model can simulate various protection types, such as overcurrent protection, overvoltage protection, and differential protection. The model can determine whether protection actions need to be triggered based on the power system's operating status and fault conditions. The power system model building unit can construct a complete power system model, providing basic data for the calculation unit to perform subsequent fault calculations and simulations. The simulation platform for simulating the power system can be the DDRTS digital-physical hybrid simulation platform or any other simulation platform that can achieve the above functions.

[0057] The computational unit is connected to the power system model building unit and performs calculations based on the finite-difference time-domain algorithm using the nodal voltage method. The power grid in the power system model is divided into discrete networks, and time and space are discretized. For example, transmission lines are divided into several small segments, and time is divided into several small time steps. Through the discretized model, accurate simulations of the dynamic changes in current and voltage throughout the entire process from the occurrence of a fault to its clearing are achieved. Within each time step, the voltage and current of each node are calculated using the nodal voltage method, thus obtaining the changes in current and voltage throughout the entire fault process. The computational unit provides accurate dynamic data on current and voltage changes to the full-process fault simulation unit for simulating the entire fault process.

[0058] For the full-process fault simulation unit, the initialization subunit initializes the entire simulation system, setting initial operating conditions such as the initial states of each component and the initial voltage and current of nodes. The fault occurrence subunit simulates the occurrence of a fault when the simulation time reaches the preset fault moment, introducing corresponding fault conditions into the power system model based on the fault type and location set by the fault scenario construction unit. The fault development subunit continuously simulates the propagation process of the fault in the power grid over time, analyzing how the fault propagates in transmission lines, transformers, and other components, and its impact on other parts of the power grid, based on the dynamic changes in current and voltage obtained by the calculation unit. The protection action subunit issues protection actions according to preset action logic when the relay protection device model detects a fault current exceeding the action threshold. For example, when overcurrent protection detects a current exceeding the set threshold, it triggers the circuit breaker to trip, disconnecting the faulty line. By simulating the entire fault occurrence process in stages, the system comprehensively demonstrates the impact of the fault on the power system and the operation of the relay protection device, providing important reference for the design, operation, and maintenance of the power system.

[0059] In one specific implementation, a multi-dimensional result display unit is also included, which includes:

[0060] The current and voltage change curve unit uses a visual interface to plot the current and voltage change curves of each key node during the fault, with time as the horizontal axis and current and voltage amplitude as the vertical axis.

[0061] The relay protection device operation process display unit shows the action sequence, time delay, and execution of the working logic of the relay protection device in the form of a timeline.

[0062] The status change display unit uses a 3D model to show the status changes of power grid equipment during a fault process.

[0063] Specifically, the multi-dimensional results display unit also includes an export module, which is used to export data from the simulation process into standard format files.

[0064] In the above embodiments, the current and voltage change curve unit, presented intuitively, can quickly locate abnormal fluctuations in current and voltage at key nodes during a fault. For example, when a short-circuit fault occurs on a transmission line, the curve clearly shows the sharp rise in current and the significant drop in voltage at the moment of the fault, enabling personnel to accurately determine the timing and severity of the fault, thus facilitating rapid fault 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, the changing patterns of current and voltage during the transient process can be studied in depth, thereby assessing the stability of the power system. The relay protection device operation process display unit presents the sequence of actions and time delays in the form of a timeline, allowing for intuitive inspection of whether the protection device operates correctly according to the preset logic. For example, in a multi-level protection configuration system, the timeline clearly shows the sequence of actions of the main protection and backup protection, as well as the time intervals between each action, verifying whether the protection device has problems such as maloperation, failure to operate, or unreasonable operating time, ensuring that the relay protection device can effectively isolate the fault at critical moments and protect the safety of the power system. The status change display unit uses 3D models to vividly present the status changes of power grid equipment during a fault. For example, it allows users to visually observe the tripping action of the circuit breaker on the faulty line and the color change of the heat sink when the transformer oil temperature rises.

[0065] In one specific implementation, the fault scenario construction unit specifically includes:

[0066] The fault type generation module uses deep learning algorithms to analyze a large amount of historical fault data, real-time power grid parameters, and power system status monitoring data. By constructing a fault mode recognition model, it generates fault types for transmission lines of different voltage levels.

[0067] The spatiotemporal parameter setting module receives fault location information determined by the GIS platform in real time; the time signal provided by the real-time clock synchronization system is also transmitted to the spatiotemporal 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 spatiotemporal parameter setting module, enabling the full-process fault simulation unit to control the duration of the fault simulation.

[0068] The fault duration calculation model calculates the fault duration by obtaining the operating time range and operating logic of distance protection, zero-sequence protection or differential protection based on the operating characteristics of different types of relay protection devices in the power grid.

[0069] This also includes a GIS platform module, whose specific functions are:

[0070] Geographic information data of the power grid is collected and combined with power grid topology data to obtain the operating characteristic parameters of all relay protection devices in the power grid. These operating characteristic parameters include the operating time range and operating logic of various relay protection devices, as well as the tripping time parameters of circuit breakers. The construction process is as follows:

[0071] Build a GIS platform for the power grid and import the power grid geographic information data and power grid topology data into the power grid GIS platform;

[0072] Deploy a clock synchronization system to precisely calibrate the simulation system's time with the clock synchronization system, so that the fault is triggered precisely at the set microsecond level.

[0073] In the GIS platform module, the faulty line and the fault location are determined, providing fault location information to the spatiotemporal parameter setting module.

[0074] In the above implementation, various fault records accumulated over a long period of time from the operation of the power system are collected, including fault information occurring at different voltage levels (such as 110kV, 220kV, 500kV, etc.) at different times and geographical locations. For example, details of short-circuit and open-circuit faults on different transmission lines over the past few years are included, along with the time and location of the faults, and the operating status of the power grid before the fault, such as the voltage at each node, line current, and power distribution. This data forms the basis for deep learning algorithms to discover fault patterns; specifically, the deep learning algorithm can employ recurrent neural networks. Real-time acquisition of current power system operating parameters, such as the voltage amplitude and phase at each node (reflecting the magnitude and angle of the node voltage) and the magnitude and direction of current in the lines (visually showing the current flow in the transmission lines), allows the model to grasp the current operating status of the power grid and accurately predict fault types. Various sensors and monitoring devices are used to collect status information of power system equipment, such as transformer oil temperature and winding temperature (excessive oil temperature may indicate overheating faults inside the transformer); oil gas composition (abnormal levels of certain gases may indicate insulation damage or other problems inside the transformer); transmission line sag and conductor temperature (changes in sag may affect the safe distance of the line, and excessive conductor temperature may be caused by overload); and insulator leakage current (abnormal leakage current may indicate deterioration of insulator performance). This data helps identify potential equipment faults and provides important information 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 regularities from complex data. By constructing fault pattern recognition models, the models learn the mapping relationships between different fault types and various types of data. For example, when the model learns that under a specific combination of power grid parameters, abnormal changes in certain equipment status monitoring data may indicate a high probability of a certain type of short-circuit fault, and similar data characteristics appear during subsequent operation, the model can accurately predict the possible fault type, providing a basis for fault simulation.

[0075] The GIS platform can monitor the geographical location of transmission lines in real time and determine the possible location of faults by associating with the power system model. When an abnormal signal is detected at a monitoring point on the transmission line, the GIS platform can quickly locate the point's specific position on the line and transmit the information to the spatiotemporal parameter setting module in real time. This enables fault simulation to be carried out in a specific geographical location, more realistically reflecting the actual situation. The real-time clock synchronization system provides a high-precision time signal to ensure time synchronization of the power system. The spatiotemporal parameter setting module receives this signal, providing a unified and accurate time starting point for the entire fault simulation unit. In the fault simulation, the fault occurrence time, the duration of each stage, etc., all have precise time references, which helps to analyze the impact of the fault on the power system at different times. The fault duration calculation model calculates the 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 often used to respond to phase-to-phase short-circuit faults on transmission lines, and its operating time depends on the distance from the fault point to the protection installation location and the protection setting range; zero-sequence protection is mainly for ground faults, and its operating time is also set accordingly. The fault duration calculation model obtains the operating time range of these protection devices, providing basic data for calculating the fault duration. In addition to the operating time range, the operating logic of the protection devices is also included in the calculation. In a multi-level protection configuration, the primary protection operates first; if the primary protection fails to operate, the backup protection operates. The fault duration calculation model needs to analyze this operating logic to determine the time required from the occurrence of the fault to the protection device's action to clear the fault under different fault scenarios. The calculation results are fed back to the spatiotemporal parameter setting module, enabling the full-process fault simulation unit to accurately control the fault simulation duration and realistically simulate the entire process from fault occurrence to fault clearance.

[0076] For the GIS platform module, geographic information of the power grid coverage area is collected, including topography, building distribution, and transportation routes. This geographic information is crucial for understanding the environment surrounding transmission lines and analyzing the potential impact of environmental factors on faults. For example, transmission lines in mountainous areas are more prone to faults due to severe weather, landslides, and other geological disasters. Power grid topology data describes the connection relationships between various components in the power system (such as generators, transformers, transmission lines, and loads). Combining geographic information data with power grid topology data allows for a visual representation of the power grid layout in geographic space. Simultaneously, the operating characteristic parameters of all relay protection devices in the power grid can be obtained, including the operating time range of various relay protection devices, such as the operating time settings for distance protection stages I, II, and III; operating logic, such as the coordination logic between main protection and backup protection; and circuit breaker tripping time parameters. These parameters are essential for accurately simulating fault processes and the actions of protection devices. The collected power grid geographic information data and power grid topology data are imported into a specially constructed power grid GIS platform module, which can display the distribution of the power grid in an intuitive map format. It clearly shows the routes of transmission lines, the locations of substations, and the spatial relationships of various power equipment. This not only facilitates daily management and maintenance of the power grid but also provides a visual foundation platform for constructing fault scenarios. A high-precision clock synchronization system is deployed, and the simulation system time is precisely calibrated with the clock synchronization system. This ensures that the fault is triggered precisely at the set microsecond level in the fault scenario construction. In power system simulation, the accuracy of time is crucial for simulating the instant of fault occurrence and the time sequence of subsequent stages, making the simulation results more consistent with the temporal characteristics of actual power system faults. Utilizing the powerful spatial analysis capabilities of the GIS platform module, combined with the power grid topology and real-time monitoring data, the faulty line and fault location can be determined. For example, when abnormal changes in the current and voltage of a transmission line are detected, the GIS platform module can quickly locate the specific faulty line and the location of the fault 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.

[0077] In one specific embodiment, the full-process simulation execution unit specifically includes:

[0078] The initialization subunit is responsible for inputting parameters of each component in the power system model, including voltage amplitude, phase, load power, and initial equipment temperature.

[0079] The fault occurrence subunit establishes the correlation mapping relationship between the power system model's state monitoring data, power grid operating parameter change data, and external environment data. When the simulation time reaches the preset fault time, it acquires data from each data source in real time and makes a comprehensive judgment based on the correlation rules to determine whether to trigger the fault simulation.

[0080] The fault propagation subunit divides the power grid model into multiple sub-models based on region, voltage level, and component importance. Based on the performance parameters of each computing node, computing task allocation rules are set. When a fault occurs, different sub-models are assigned to appropriate computing nodes to perform parallel fault propagation calculations according to the pre-set task allocation rules.

[0081] The protection action subunit monitors the power grid operation status in real time. When a fault occurs and the relay protection device is activated, it automatically matches the corresponding protection strategy and adjusts the contingency 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 according to the contingency plan to avoid unnecessary large-scale power outages due to excessive sensitivity; during off-peak load periods, the fault is quickly cleared according to the contingency plan.

[0082] In the above implementation, the fault occurrence subunit establishes a correlation mapping relationship between the power system model's state monitoring data, power grid operating parameter change data, and external environmental data. When the simulation time reaches the preset fault moment, data from each data source is acquired in real time, and a comprehensive judgment is made based on the correlation rules to determine whether to trigger the fault simulation. This multi-source data fusion and correlation analysis method can more realistically simulate the situation where the power system is affected by multiple factors and causes faults in actual operation. Compared with single data judgment, it greatly improves the accuracy and reliability of fault trigger judgment, reduces the possibility of misjudgment and omission, makes the fault simulation more in line with the actual scenario, and provides a more accurate starting point for subsequent fault response strategy research. The fault development subunit divides the power grid model into multiple sub-models according to region, voltage level, and component importance, and sets computation task allocation rules according to the performance parameters of each computing node. For example, sub-models with high complexity and large computational requirements, such as power grid area sub-models with high voltage levels and a large number of components, are preferentially allocated to computing nodes with strong computing capabilities (such as high CPU speed and large memory capacity). After a fault occurs, different sub-models can be allocated to appropriate computing nodes according to the pre-set rules to perform parallel computation of 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, it shortens simulation computation time, enabling faster acquisition of detailed information on fault development and timely formulation of effective fault response measures, thereby enhancing the emergency response capability of the power system under fault conditions. The protection action subunit can monitor the power grid operating conditions in real time. When a fault occurs and the relay protection device is activated, it automatically matches the corresponding protection strategy and adjusts the contingency plan according to the current operating conditions. During peak load periods, the action time limit of the protection device is appropriately extended and the action sensitivity is reduced to avoid unnecessary large-scale power outages due to excessive sensitivity, ensuring the continuous power supply capacity of the power system under high load demand. During off-peak load periods, the fault is quickly cleared according to the contingency plan to prevent the fault from expanding and causing greater impact on the power system. This adaptive protection strategy adjustment mechanism can flexibly optimize the action of the relay protection device according to the characteristics of different operating conditions of the power system, improve the reliability and stability of the power system under various conditions, and reduce power outages and economic losses caused by improper protection.

[0083] In one specific implementation, the power system model building unit specifically includes:

[0084] Based on the parameters of winding resistance, leakage inductance, magnetizing inductance, and core saturation characteristics, the electromagnetic characteristic changes of the transformer during the fault process are simulated.

[0085] The Bergeron model is used to simulate the transmission line, reflecting the wave process, transient characteristics, and voltage and current distribution along the line.

[0086] Based on real-time power grid operation information, the system automatically matches the corresponding power consumption scenarios 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 consumption scenario includes the power consumption characteristics and variation patterns of different load types in that scenario.

[0087] The relay protection device model is constructed based on the actual protection device's operating logic, setting parameters, and hardware characteristics, including distance protection, zero-sequence protection, and differential protection.

[0088] In the above implementation, winding resistance, leakage inductance, magnetizing inductance, and core saturation characteristic parameters are key factors describing the electromagnetic characteristics of a transformer. Winding resistance determines the energy loss when current flows 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 characteristic parameters reflect the magnetization characteristics of the core under different magnetic field strengths. During a fault, these parameters change, thus affecting the transformer's electromagnetic characteristics. For example, when a short-circuit fault occurs, the winding current increases sharply, increasing the heat generated by the winding resistance, which may cause a change in resistance value. Simultaneously, the strong magnetic field generated by the short-circuit current causes the core to enter a saturated state, altering the magnetizing inductance and core saturation characteristic parameters. By accurately simulating the changes in these parameters, the electromagnetic characteristics of the transformer during a fault can be realistically reflected, such as voltage distortion and current imbalance. Based on real-time grid operation information, such as voltage, frequency, and power parameters, the appropriate power consumption scenario can be automatically matched. Different power consumption scenarios, such as industrial, residential, and commercial scenarios, have different power consumption characteristics and changing patterns. Based on the matching results of electricity consumption 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 consumption 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 electricity consumption characteristics under that scenario. Through this dynamic adjustment, the load model can more realistically simulate load changes under different electricity consumption scenarios, improving the accuracy of power system simulation. The Bergeron model is a widely used model for transmission line simulation. Based on traveling wave theory, it can accurately reflect the wave process of transmission lines. During operation, when a fault occurs or interference occurs, a traveling wave is generated on the transmission line. The traveling wave propagates along the transmission line and undergoes reflection, refraction, and other phenomena.

[0089] In one specific embodiment, the computing unit is specifically:

[0090] Based on the establishment of a power system component importance assessment system, components are classified according to their location in the power grid, capacity, and degree of impact on power system stability. For critical components, a smaller grid size is pre-set. The grid division is dynamically adjusted according to the fault type and propagation direction. Specifically, the grid is gradually densified along the fault propagation path, and the grid size is increased in areas far from the fault area and where electrical quantities change steadily.

[0091] The importance of components is specifically categorized as follows, in the form of a score:

[0092] 1) Grid topology location: Components located at or above the core hub of the power grid, such as regional interconnection stations or junctions of multiple circuits. Scoring is based on the number of circuits; two circuits converging count as 2 points, and no circuits converging count as 1 point.

[0093] 2) Equipment capacity and functions

[0094] High-capacity equipment: high-capacity generators, main transmission lines (such as 500kV / 220kV), large-capacity transformers, etc., whose failures may cause power imbalances across the entire network, are of high importance; scored as 3 points.

[0095] Key functional equipment: system stability control devices, starting power supplies, etc., directly affect the system's recovery capability, and are worth 2 points.

[0096] The remaining equipment is counted as 1 point.

[0097] 3) The degree of impact on system stability

[0098] Components that may trigger cascading trips after being disconnected (such as lines on important transmission sections) require the highest priority protection; this is scored as 3 points.

[0099] Reactive power compensation equipment that affects voltage stability (such as SVG, capacitor banks), or large generator sets that support system frequency; counted as 2 points.

[0100] The remaining equipment is counted as 1 point.

[0101] Among them, the following indicators are used to refer to the stability of changes in electrical quantities:

[0102] 1) Amplitude fluctuation rate (voltage or current), for example, fluctuation within a 10ms window is less than 0.5% (high voltage grid) or 1% (medium voltage grid).

[0103] 2) Duration of continuous stability, for example, the state is maintained continuously for ≥30μs, with 3 simulation steps.

[0104] A layered distributed computing architecture is constructed, dividing computing resources into three layers: the bottom layer consists of local computing nodes, which are responsible for handling routine sub-model computing tasks with small computational loads; the middle layer consists of regional computing clusters, which are composed of multiple local computing nodes and are responsible for sub-model computing tasks with moderate computational complexity and frequent data interaction; the top layer consists of the core computing center, which is responsible for sub-model computing tasks that contain a large number of complex components and have a significant impact on the overall system.

[0105] Establish a multi-dimensional result verification unit, including: verifying the current and voltage results calculated at each simulation step to ensure the conservation of global electrical quantities; comparing and verifying the key electrical quantity characteristics of the current simulation results with similar fault cases in the standard fault case library; and providing manual correction tools for operators to manually adjust the parameters in the calculation model.

[0106] In the above implementation, by establishing a power system component importance assessment system, components are classified according to their location, capacity, and impact on system stability. A smaller grid size is pre-set for critical components, significantly improving the computational accuracy of critical component fault simulation. For example, transformers in hub substations, as critical components, can have their internal electromagnetic transient processes simulated more meticulously using a small grid size. This captures minute but potentially significant changes in electrical quantities that could have a major impact on the system, ensuring accurate assessment of the impact of critical component faults on the system and avoiding misjudgments due to insufficient computational accuracy. Dynamically adjusting the grid partitioning based on fault type and propagation direction, gradually densifying the grid along the fault propagation path, accurately captures rapid changes in electrical quantities during fault propagation, ensuring precise calculation of critical fault development areas. Increasing the grid size in areas far from the fault and where electrical quantity changes are stable reduces unnecessary computation and avoids resource waste. This dynamic grid partitioning strategy, while ensuring computational accuracy, greatly improves overall computational efficiency, shortens fault simulation time, and enables faster acquisition of the full picture of fault development, allowing for timely countermeasures. A hierarchical distributed computing architecture was constructed, dividing computing resources into three layers: local computing nodes, regional computing clusters, and core computing centers, achieving precise matching between computing tasks and computing resources. A multi-dimensional result verification unit verifies the current and voltage results calculated at each simulation step, ensuring the conservation of global electrical quantities, which is crucial for ensuring the accuracy of the calculation results. The conservation of electrical quantities is a fundamental physical law of power system operation. Verification can promptly detect errors or deviations in the calculation process, such as non-conservation of electrical quantities caused by numerical calculation errors, thereby ensuring that the simulation results conform to actual physical principles.

[0107] The number of devices and processing scale described herein are for the purpose of simplifying the description of the invention. Applications, modifications, and variations of the invention will be readily apparent to those skilled in the art.

[0108] Although embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for the present invention. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details and illustrations shown and described herein.

Claims

1. A relay protection equipment simulation system based on virtual digitalization, characterized in that, 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 in transmission lines of different voltage levels and to set the time, location, duration, and type of the fault; it provides fault parameters for the power system model construction unit. The power system model building unit simulates the dynamic changes in electromagnetic characteristics during fault occurrence based on the transformer model and its parameters; it simulates the wave process, transient characteristics, and voltage and current distribution patterns along the transmission line based on the transmission line model and the model reflecting distributed parameters; and it simulates the dynamic changes in load under different operating conditions based on the load model and various load types. Simulation of various relay protection types based on relay protection device models; The computing unit, based on the time-domain finite-difference algorithm of the nodal voltage method, divides the power grid of the power system model into a discrete network and discretizes time and space to achieve accurate simulation of the dynamic changes of current and voltage from the moment a fault occurs to the entire process of its clearing. The full-process fault simulation unit simulates the entire fault occurrence process in stages based on the results of the calculation unit. The full-process fault simulation 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 the parameters of each component in the power system model, including voltage amplitude, phase, load power, and initial equipment temperature; The fault occurrence subunit is used to establish the correlation mapping relationship between the power system model's state monitoring data, power grid operating parameter change data, and external environment data. When the simulation time reaches the preset fault time, it acquires data from each data source in real time and makes a comprehensive judgment based on the correlation rules to determine whether to trigger the fault simulation. The fault propagation subunit divides the power grid model into multiple sub-models based on region, voltage level, and component importance. It sets calculation task allocation rules according to the performance parameters of each computing node. When a fault occurs, different sub-models are assigned to appropriate computing nodes to perform parallel calculations of fault propagation according to the pre-set task allocation rules. The protection action subunit monitors the power grid operation status 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, it extends the action time limit of the protection device and reduces the action sensitivity to avoid large-scale power outages caused by excessive sensitivity; during off-peak load periods, it quickly disconnects the fault.

2. The relay protection equipment simulation system based on virtual digitization as described in 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 status change display unit; The current and voltage change curve unit uses a visualization interface to plot the current and voltage change curves of the node during the fault period, with time as the horizontal axis and current and voltage amplitude as the vertical axis. The relay protection device operation process display unit displays the action sequence, time delay, and execution status of the working logic of the relay protection device in the form of a timeline. The state change display unit uses a 3D model to show the state changes of power grid equipment during a fault process.

3. The relay protection equipment simulation system based on virtual digitization as described in claim 2, characterized in that, It also includes a GIS platform module, which is used to collect geographic information data of the power grid, combine it with power grid topology data, obtain the operating characteristic parameters of all relay protection devices in the power grid, and determine the faulty line and the fault occurrence point on the GIS platform module, providing fault location information for the spatiotemporal parameter setting module in the fault scenario construction unit; the operating characteristic parameters include the operating time range, operating logic of various relay protection devices, and circuit breaker tripping time parameters; its construction process is as follows: 1) Construct a GIS platform for the power grid and import the power grid geographic information data and power grid topology data into the power grid GIS platform; 2) Deploy a clock synchronization system to calibrate the simulation system's time with the clock synchronization system so that the fault is triggered precisely at the set microsecond level.

4. The relay protection equipment simulation system based on virtual digitization as described in claim 1, characterized in that, The fault scenario construction unit includes a fault type generation module and a time-space parameter setting module. The fault type generation module uses deep learning algorithms to analyze historical fault data, real-time power grid parameters, and power system status monitoring data. By constructing a fault mode recognition model, it generates fault types for transmission lines at different voltage levels. The spatiotemporal parameter setting module receives in real time the fault location information determined by the GIS platform, the time signal provided by the clock synchronization system, and the calculation results of the fault duration calculation model, providing a time reference for the full-process fault simulation unit, and controlling the duration of the fault simulation through the full-process fault simulation unit. The fault duration calculation model calculates the fault duration by obtaining the operating time range and operating logic of distance protection, zero-sequence protection or differential protection based on the operating characteristics of different types of relay protection devices in the power grid.

5. The relay protection equipment simulation system based on virtual digitization as described in claim 1, characterized in that, The specific functions of the power system model building unit are as follows: 1) Simulate the changes in electromagnetic characteristics of a transformer during a fault process based on parameters such as winding resistance, leakage inductance, magnetizing inductance, and core saturation characteristics. 2) The Bergeron model is used to simulate the transmission line, reflecting the wave process, transient characteristics, and voltage and current distribution along the line. 3) Based on real-time power grid operation information, automatically match the corresponding power consumption scenario and dynamically adjust the proportion and parameters of different load types in the load model. The load types include: constant power, constant current, constant impedance and asynchronous motor; wherein, each power consumption scenario includes the power consumption characteristics and variation law of different load types in the scenario. 4) Construct a relay protection device model based on the actual protection device's operating logic, setting parameters, and hardware characteristics.

6. The relay protection equipment simulation system based on virtual digitization as described in claim 1, characterized in that, The specific functions of the computing unit are as follows: 1) Establish a power system component importance assessment system: classify components according to their location, capacity and impact on power system stability, and pre-set the grid size of the components; dynamically adjust the grid division according to the fault type and propagation direction; specifically: gradually densify the grid along the fault propagation path, and increase the grid size in areas far from the fault area and where electrical quantities change steadily. 2) Construct a hierarchical distributed computing architecture: Divide computing resources into different layers to compute sub-model computing tasks of different complexities respectively; 3) Establish a multi-dimensional result verification unit: verify the current and voltage results calculated at each simulation step to ensure the conservation of global electrical quantities; compare and verify the current simulation results with the electrical quantity characteristics of fault cases in the standard fault case library.

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

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