Circuit breaker fault diagnosis method and system based on simulation model

Abstract

The application provides a circuit breaker fault diagnosis method and system based on a simulation model, and relates to the technical field of fault diagnosis. The method comprises the following steps: pre-constructing a three-dimensional electromagnetic field simulation model and a temperature field simulation model of a circuit breaker; performing coupling simulation to construct a benchmark database; acquiring a real-time operating current, collecting a real-time temperature distribution, and retrieving target associated working condition mapping data; calling target simulation temperature and performing pixel-level deviation comparison with the real-time temperature distribution; backtracking parameter adjustment according to the temperature deviation threshold area; performing fault determination according to the fault root cause and the temperature deviation threshold area, and outputting a real-time fault type and an alternative maintenance strategy. The application solves the technical problem of low circuit breaker fault diagnosis accuracy in the prior art due to the insensitivity of traditional methods to early local faults and slow-changing degradation of the circuit breaker, and improves the circuit breaker fault diagnosis accuracy through coupling simulation of the three-dimensional electromagnetic field simulation model and the temperature field simulation model.

Description

Technical Field

[0001] This application relates to the field of fault diagnosis technology, specifically to a circuit breaker fault diagnosis method and system based on simulation models. Background Technology

[0002] Traditional circuit breaker fault monitoring methods rely heavily on real-time parameter monitoring and are typically used to detect more obvious fault modes, such as overload or short circuit. While they can provide effective early warnings when a circuit breaker experiences a more severe fault, they have significant limitations in monitoring early-stage localized faults and gradual degradation. Especially when circuit breakers exhibit minor faults such as contact wear, electromagnetic component failure, or insulation aging, traditional monitoring technologies often fail to capture these subtle changes in a timely manner. This affects early fault diagnosis and accurate location, resulting in lower diagnostic accuracy when dealing with minor faults and gradual degradation, easily leading to missed or misdiagnosed cases.

[0003] In summary, existing technologies suffer from the problem of low accuracy in circuit breaker fault diagnosis because traditional methods are insensitive to early localized faults and gradual degradation of circuit breakers. Summary of the Invention

[0004] The purpose of this application is to provide a circuit breaker fault diagnosis method and system based on simulation models, in order to solve the technical problem that the existing technology has low circuit breaker fault diagnosis accuracy due to the insensitivity of traditional methods to early local faults and slow degradation of circuit breakers.

[0005] To achieve the above objectives, this application provides a circuit breaker fault diagnosis method and system based on simulation models.

[0006] Firstly, this application provides a circuit breaker fault diagnosis method based on a simulation model. This method is implemented through a circuit breaker fault diagnosis system based on a simulation model. The method includes: pre-constructing a three-dimensional electromagnetic field simulation model and a temperature field simulation model of the circuit breaker; performing coupled simulations on the three-dimensional electromagnetic field simulation model and the temperature field simulation model to output multiple sample operating condition correlation mapping data and construct a benchmark database; acquiring real-time operating current using the circuit breaker's built-in Hall sensor; and driving a non-contact infrared thermal imager. The system collects the real-time temperature distribution of the circuit breaker in real-time distributed diagnostic coordinates; uses the real-time operating current and real-time distributed diagnostic coordinates as two-dimensional search conditions to retrieve target-related operating condition mapping data from the benchmark database; retrieves the target simulation temperature from the target-related operating condition mapping data and compares it with the real-time temperature distribution at the pixel level to locate the temperature deviation exceeding the threshold region; performs backtracking parameter tuning of the three-dimensional electromagnetic field simulation model based on the temperature deviation exceeding the threshold region and outputs the root cause of the fault; and determines the fault based on the root cause of the fault and the temperature deviation exceeding the threshold region, outputting the real-time fault type and alternative maintenance strategies.

[0007] Optionally, a basic device skeleton is constructed based on the three-dimensional structural data of the circuit breaker; the structural material properties and operating condition range are used as boundary conditions to initialize the basic device skeleton, generating the three-dimensional electromagnetic field simulation model; after inputting the operating current, electromagnetic field distribution is simulated in the three-dimensional electromagnetic field simulation model, and distributed electromagnetic loss is output; the distributed electromagnetic loss is used as a heat source input to the temperature field simulation framework to simulate the temperature field distribution, establishing the temperature field simulation model.

[0008] Optionally, the rated parameters are retrieved via network according to the circuit breaker ID, and the rated parameters are used as constraints for the current scanning range to set multiple sample operating current conditions; environmental boundary conditions are set according to the application scenario of the circuit breaker; the environmental boundary conditions are used as temperature field boundary parameters, and the multiple sample operating current conditions are input into the three-dimensional electromagnetic field simulation model in ascending order to solve Maxwell's equations, outputting multiple sample simulated electromagnetic losses; the multiple sample simulated electromagnetic losses are input into the temperature field simulation model as spatial heat sources to perform heat conduction solutions, outputting multiple sample simulated temperature distributions, wherein the multiple sample simulated temperature distributions carry multiple sample distributed diagnostic coordinate identifiers; the multiple sample distributed diagnostic coordinates, multiple sample operating current conditions, multiple sample simulated electromagnetic losses, and multiple sample simulated temperature distributions are associated and bound to generate the multiple sample operating condition association mapping data.

[0009] Optionally, the associated operating condition mapping data for each sample includes the sample distributed diagnostic coordinates, the sample operating current conditions, the sample simulated electromagnetic loss, and the sample simulated temperature distribution.

[0010] Optionally, after limiting the current scanning range based on the historical typical operating conditions of the circuit breaker, the scanning step size density is configured in a gradient manner according to the historical load frequency distribution.

[0011] Optionally, the real-time operating current is used as a primary index to traverse multiple sample operating condition currents in the benchmark database, and a first sample associated operating condition mapping data group is output; the real-time distributed diagnostic coordinates are used as a secondary index to traverse N sample distributed diagnostic coordinates in the first sample associated operating condition mapping data group to solve for spatial neighborhood deviation, and obtain N spatial proximity values; according to the descending order of the N spatial proximity values, the target associated operating condition mapping data is retrieved from the first sample associated operating condition mapping data group.

[0012] Optionally, P associated physical parameter types limited to the temperature deviation exceeding the threshold region are retrieved from the device's basic framework; iterative inversion parameter tuning of the P associated physical parameter types is performed on the three-dimensional electromagnetic field simulation model until the temperature distribution of the three-dimensional electromagnetic field simulation model reproduces the real-time temperature distribution, and the degradation amount of the P parameters is output; P reference initial parameter values ​​of the P associated physical parameter types are locally called; the degradation amount of the P parameters and the P reference initial parameter values ​​are mapped and compared to perform fault location and output the root cause of the fault.

[0013] Optionally, the overheating distribution morphology attribute is calculated based on the spatial contour parameters of the temperature deviation exceeding the threshold region; the overheating distribution morphology attribute and the root cause of the fault are input into a fault decision tree for matching and outputting the real-time fault type; the maintenance strategy is matched based on the real-time fault type using the temperature deviation exceeding the threshold region as a spatial constraint, and the alternative maintenance strategy is output.

[0014] Optionally, if the real-time fault type involves live operation, dynamic safety verification rules are added to the alternative maintenance strategy, and a modified maintenance strategy is output.

[0015] Secondly, this application also provides a circuit breaker fault diagnosis system based on a simulation model, used to execute the circuit breaker fault diagnosis method based on a simulation model as described in the first aspect, wherein the circuit breaker fault diagnosis system based on a simulation model includes: a model pre-construction module for pre-constructing a three-dimensional electromagnetic field simulation model and a temperature field simulation model of the circuit breaker; a coupling simulation module for performing coupled simulation on the three-dimensional electromagnetic field simulation model and the temperature field simulation model, outputting multiple sample operating condition correlation mapping data, and constructing a benchmark database; a current acquisition module for acquiring real-time operating current through the Hall sensor built into the circuit breaker; and a temperature acquisition module for driving a non-contact infrared thermal imager to acquire the temperature. The system includes: a real-time temperature distribution of the circuit breaker in real-time distributed diagnostic coordinates; a data retrieval module, which uses the real-time operating current and real-time distributed diagnostic coordinates as two-dimensional retrieval conditions to retrieve target-related operating condition mapping data from the benchmark database; a deviation comparison module, which retrieves the target simulation temperature from the target-related operating condition mapping data and performs pixel-level deviation comparison with the real-time temperature distribution to locate the temperature deviation exceeding the threshold region; a backtracking parameter tuning module, which performs backtracking parameter tuning of the three-dimensional electromagnetic field simulation model based on the temperature deviation exceeding the threshold region and outputs the root cause of the fault; and a fault determination module, which determines the fault based on the root cause of the fault and the temperature deviation exceeding the threshold region and outputs the real-time fault type and alternative maintenance strategies.

[0016] One or more technical solutions provided in this application have at least the following technical effects or advantages: A baseline database is constructed by pre-constructing a three-dimensional electromagnetic field simulation model and a temperature field simulation model of the circuit breaker; coupling the three-dimensional electromagnetic field simulation model and the temperature field simulation model to output multiple sample operating condition correlation mapping data; acquiring the real-time operating current through the circuit breaker's built-in Hall sensor; driving a non-contact infrared thermal imager to acquire the real-time temperature distribution of the circuit breaker in real-time distributed diagnostic coordinates; using the real-time operating current and real-time distributed diagnostic coordinates as two-dimensional search conditions to retrieve target correlation operating condition mapping data from the baseline database; retrieving the target simulation temperature from the target correlation operating condition mapping data and comparing it with the real-time temperature distribution at the pixel level to locate the temperature deviation exceeding the threshold region; performing backtracking parameter tuning of the three-dimensional electromagnetic field simulation model based on the temperature deviation exceeding the threshold region to output the root cause of the fault; and determining the fault based on the root cause of the fault and the temperature deviation exceeding the threshold region to output the real-time fault type and alternative maintenance strategies. In other words, by constructing a three-dimensional electromagnetic field simulation model and a temperature field simulation model and performing coupled simulation, the simulation efficiency is improved; real-time operating current and real-time temperature distribution are obtained, target-related operating condition mapping data are retrieved from the benchmark database, and the real-time temperature distribution is compared with the simulation prediction temperature. If the deviation exceeds the threshold, it is determined that the circuit breaker has a local overheating fault. Combined with the results of backtracking parameter tuning, the root cause of the fault is determined, the fault type is output, and alternative maintenance strategies are given, thereby improving the accuracy and efficiency of circuit breaker fault diagnosis, reducing the risk of equipment damage, optimizing maintenance resources, and reducing downtime due to faults.

[0017] The above description is merely an overview of the technical solution of this application. To better understand the technical means of this application and to facilitate its implementation according to the description, and to make the above and other objects, features, and advantages of this application more apparent, specific embodiments of this application are described below. It should be understood that the content described in this section is not intended to identify key or important features of the embodiments of this application, nor is it intended to limit the scope of this application. Other features of this application will become readily apparent through the following description. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are merely exemplary. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0019] Figure 1 This is a flowchart illustrating the circuit breaker fault diagnosis method based on a simulation model according to this application.

[0020] Figure 2This is a schematic diagram of the circuit breaker fault diagnosis system based on the simulation model of this application.

[0021] Figure labeling: Model pre-construction module 11, Coupled simulation module 12, Current acquisition module 13, Temperature acquisition module 14, Data retrieval module 15, Deviation comparison module 16, Backtracking parameter tuning module 17, Fault determination module 18. Detailed Implementation

[0022] This application provides a circuit breaker fault diagnosis method and system based on simulation models, solving the technical problem of low fault diagnosis accuracy in existing technologies due to the insensitivity of traditional methods to early localized faults and gradual degradation of circuit breakers. By constructing a three-dimensional electromagnetic field simulation model and a temperature field simulation model, and performing coupled simulations, simulation efficiency is improved. Real-time operating current and temperature distribution are obtained, and target-related operating condition mapping data are retrieved from a benchmark database. The real-time temperature distribution is compared with the simulated predicted temperature. If the deviation exceeds a threshold, a localized overheating fault is identified in the circuit breaker. Combined with the results of backtracking parameter tuning, the root cause of the fault is determined, the fault type is output, and alternative maintenance strategies are provided. This improves the accuracy and efficiency of circuit breaker fault diagnosis, reduces the risk of equipment damage, optimizes maintenance resources, and reduces downtime.

[0023] The technical solutions of this application will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. It should be understood that this application is not limited to the exemplary embodiments described herein. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application. It should also be noted that, for ease of description, only the parts related to this application are shown in the accompanying drawings, not all of them.

[0024] Example 1, please refer to the appendix. Figure 1 This application provides a circuit breaker fault diagnosis method based on a simulation model, wherein the simulation model-based circuit breaker fault diagnosis method is applied to a simulation model-based circuit breaker fault diagnosis system, and the simulation model-based circuit breaker fault diagnosis method specifically includes the following steps: Pre-construct three-dimensional electromagnetic field simulation model and temperature field simulation model of the circuit breaker.

[0025] Furthermore, this application also includes the following steps: constructing a basic device skeleton based on the three-dimensional structural data of the circuit breaker; initializing the basic device skeleton with structural material properties and operating condition range as boundary conditions to generate the three-dimensional electromagnetic field simulation model; after inputting the operating current, performing electromagnetic field distribution simulation in the three-dimensional electromagnetic field simulation model to output distributed electromagnetic loss; and using the distributed electromagnetic loss as a heat source input to the temperature field simulation framework to perform temperature field distribution simulation and establish the temperature field simulation model.

[0026] Specifically, the three-dimensional structural data of the circuit breaker is obtained based on CAD drawings, thereby determining the geometry and dimensions of each part of the circuit breaker and constructing the basic framework of the device. For example, the three-dimensional assembly of the circuit breaker from CAD software is imported into professional finite element analysis software, which automatically identifies and defines the contact relationships between components, forming the basic framework of the device. The three-dimensional structural data of the circuit breaker is the physical structure and geometric data of the circuit breaker, describing the size, shape, and layout of each component. The basic framework of the device is the basic geometric framework of the circuit breaker constructed based on the three-dimensional structural data. It is the foundation of the entire circuit breaker simulation model and determines the layout of the physical space in electromagnetic and thermal field simulations.

[0027] Assign realistic material properties to each component in the framework from the material library, namely the physical and chemical characteristics of each component's material, such as electrical conductivity, magnetic permeability, thermal conductivity, and density. Set the operating condition range, which is the upper and lower limits of the external electrical conditions the circuit breaker withstands under normal operating conditions. This determines the load conditions that the circuit breaker needs to simulate in the simulation, which may include overload, normal operation, and short circuit scenarios. The core parameter is the operating current. For example, for a 550kV SF6 circuit breaker, its rated current might be 3150A, and its operating condition range might be set to 0A to 4000A.

[0028] Using structural material properties and operating conditions as boundary conditions, the basic framework of the device is initialized, and a three-dimensional electromagnetic field simulation model of the circuit breaker is constructed. The three-dimensional electromagnetic field simulation model is a calculable digital model that already contains complete geometric information, material properties, and electrical excitations. Based on Maxwell's equations, it can simulate the current density distribution, magnetic field strength distribution, and resulting resistive losses inside and around the circuit breaker under a given current excitation. It is used to simulate the distribution and changes of the electromagnetic field inside the circuit breaker, and further calculate the electromagnetic effects when current flows through it.

[0029] The operating current, i.e., the current flowing through the electrodes of the circuit breaker during actual operation, is obtained to ensure it conforms to the operating condition range. The operating current can be the normal operating current or the overload current, reflecting the current-carrying capacity of the circuit breaker under different operating conditions. The operating current of the circuit breaker is input into the established three-dimensional electromagnetic field simulation model. Based on the input current, the flow of current inside the circuit breaker is simulated, and the electromagnetic field strength of each component and the electromagnetic losses generated by the current are calculated. Distributed electromagnetic losses are the heat energy distribution generated at various points inside the conductor, directly derived from the electromagnetic field calculations, reflecting the energy loss of each component when current passes through the circuit breaker, especially at the contact points and electrodes. For the circuit breaker, its main component is Joule loss, generated by both eddy currents and resistive effects.

[0030] Distributed electromagnetic losses are used as heat sources and input into the temperature field simulation framework. The electromagnetic losses of each component are converted into heat energy, and these heat sources affect the temperature distribution inside the circuit breaker. The temperature field simulation framework uses physical processes such as heat conduction and convection to simulate the transfer of heat from high-temperature regions to low-temperature regions. The temperature field simulation framework is a thermal model to be solved, with a geometry consistent with the electromagnetic model, assigned thermal properties such as density, specific heat capacity, and thermal conductivity, and set boundary conditions such as convection, radiation, and heat conduction. In the temperature field simulation framework, engineers need to set key thermal boundary conditions, including natural convection heat dissipation coefficient, surface emissivity, and ambient temperature. Steady-state thermal simulation is initiated, using electromagnetic losses as volumetric heat sources, comprehensively considering the heat conduction of materials, surface convection, and radiation heat dissipation, and iteratively solving until thermal equilibrium is reached, finally outputting a three-dimensional temperature distribution cloud map of the entire circuit breaker. Based on the simulation results of the temperature field distribution, a complete temperature field simulation model is constructed, covering the temperature changes of all key components of the circuit breaker.

[0031] For example, let's assume we analyze the simulation results of circuit breaker L under a rated current of 3150A. The electromagnetic field simulation output shows that the loss density is highest in the contact spot region of the moving and stationary contacts, reaching 18500W / m. 3 In the typical conductive rod region, the loss density is approximately 4200 W / m. 3 The spatial loss distribution is imported into the thermal simulation module. The gas filling the circuit breaker is treated as an equivalent solid domain with a certain thermal conductivity, such as 0.015 W / (m·K). The convection coefficient on the outer casing surface is set to 8 W / (m²·K). 2 With an emissivity of 0.85 and an ambient temperature of 25°C, steady-state thermal simulation showed that the highest temperature occurred in the contact area of ​​the contact head, reaching 105.3°C. The temperature of the conductive rod connected to the terminal block was approximately 68.2°C, and the average temperature of the circuit breaker's aluminum alloy casing was approximately 45.1°C.

[0032] By pre-constructing three-dimensional electromagnetic field simulation models and temperature field simulation models, the electromagnetic and thermal effects of circuit breakers under different operating conditions are comprehensively simulated. This accurately predicts electromagnetic losses as current flows through the circuit breaker and, based on these losses, predicts the internal temperature distribution of the circuit breaker. Particularly under high current loads, it can identify potential overheating areas, thus allowing for early detection of potential faults.

[0033] By coupling the three-dimensional electromagnetic field simulation model and the temperature field simulation model, multiple sample working condition correlation mapping data are output to construct a benchmark database.

[0034] Furthermore, this application also includes the following steps: calling rated parameters via network according to the circuit breaker ID, and using the rated parameters as constraints for the current scanning range to set multiple sample operating current conditions; setting environmental boundary conditions according to the application scenario of the circuit breaker; using the environmental boundary conditions as temperature field boundary parameters, inputting the multiple sample operating current conditions in ascending order into the three-dimensional electromagnetic field simulation model to solve Maxwell's equations, and outputting multiple sample simulated electromagnetic losses; inputting the multiple sample simulated electromagnetic losses as spatial heat sources into the temperature field simulation model to perform heat conduction solutions, and outputting multiple sample simulated temperature distributions, wherein the multiple sample simulated temperature distributions carry multiple sample distributed diagnostic coordinate identifiers; associating and binding the multiple sample distributed diagnostic coordinates, multiple sample operating current conditions, multiple sample simulated electromagnetic losses, and multiple sample simulated temperature distributions to generate multiple sample condition association mapping data.

[0035] Furthermore, this application also includes the following steps: the associated operating condition mapping data for each sample includes the sample distributed diagnostic coordinates, the sample operating current conditions, the sample simulated electromagnetic loss, and the sample simulated temperature distribution.

[0036] Specifically, the process involves obtaining the circuit breaker ID, a unique identifier for each circuit breaker, similar to a device's identification number. This ID allows access to a unique file of the device on a centralized device management platform or in a cloud database. Based on the circuit breaker ID, rated parameters, including rated current, rated voltage, operating frequency, and rated power, are retrieved online, describing the circuit breaker's maximum load-bearing capacity under normal operating conditions. These rated parameters are then used as constraints for the current scanning range, setting multiple sample operating current conditions. For example, if the rated current is 3150A, the current scanning range is constrained to 0A to 4000A, with 500A increments, resulting in eight sample operating current conditions: 500A, 1000A, ..., 4000A. The current scanning range constraint defines the simulated current value range based on the rated parameters. Typically, the rated current is used as a baseline, extending downwards to cover light load conditions and upwards slightly exceeding the rated value to simulate short-term overloads. The sample operating current conditions are a series of discrete, representative current values ​​selected within the current scanning range constraints, including normal current, overload current, and short-circuit current, which serve as a series of independent simulation inputs. Environmental boundary conditions are set based on the actual application environment of the circuit breaker, such as indoor / outdoor conditions, temperature range, and humidity, for example, an ambient temperature of 35℃ and a convective heat transfer coefficient of 6 W / (m²). 2 ·K).

[0037] Environmental boundary conditions are used as temperature field boundary parameters. Multiple sample operating current conditions are sequentially input into the three-dimensional electromagnetic field simulation model from low to high. Maxwell's equations are solved to calculate the detailed three-dimensional electromagnetic loss distribution inside the circuit breaker. For circuit breakers operating under power frequency AC, eddy current field or static magnetic field equations are typically solved to calculate the current density distribution inside the conductor and the surrounding magnetic field distribution. For each specific sample operating current condition, the three-dimensional spatial volumetric power loss distribution is directly calculated after solving Maxwell's equations, yielding multiple sample simulated electromagnetic losses. These multiple sample simulated electromagnetic losses are input into the temperature field simulation model as spatial heat sources. Using the previously set environmental conditions as boundaries, heat conduction is solved to obtain multiple sample simulated temperature distributions. The sample simulated temperature distributions are the three-dimensional temperature field results of the entire circuit breaker model obtained after heat conduction for each specific sample operating current condition. Multiple sample simulated temperature distributions are accompanied by multiple sample distributed diagnostic coordinate markers, indicating the specific locations of electromagnetic losses and temperature distributions during the simulation.

[0038] For example, at 500A, the maximum loss density in the contact area is 650W / m. 3Maxwell's equations are a set of equations describing the interaction between electromagnetic fields and currents, widely used to calculate the distribution of electromagnetic fields. In simulations, Maxwell's equations are used to solve for the electromagnetic field distribution generated when current flows through a circuit breaker. For example, a 500A current excitation is applied to the input terminal of a three-dimensional electromagnetic field simulation model. The solver starts working, solving Maxwell's equations, and after finite element calculation, outputs the sample simulated electromagnetic loss under this operating condition. The loss density is highest in the contact area of ​​the contacts, assumed to be 650W / m. 3 In contrast, in the area of ​​a typical conductive rod, the power consumption is only 150W / m. 3 The three-dimensional loss distribution data is completely saved. The electromagnetic loss distribution calculated in the previous step is automatically and accurately mapped to the spatial heat source in the temperature field model. Simultaneously, the preset environmental boundary conditions are activated. The thermal solver begins working, solving the heat conduction equation until thermal equilibrium is reached. The sample simulation temperature distribution under this operating condition is output. Then, the values ​​of the preset 500 sample distributed diagnostic coordinates in this temperature field are automatically read. For example, the temperature at coordinate point 001, located at the corresponding housing of the stationary contact, is 36.8℃, and the temperature at coordinate point 002, located at the upper terminal, is 36.2℃. Once the 500A operating condition is completed, the current value is automatically increased to the next sample operating condition, such as 1000A, and then the above steps are repeated. The entire process continues until all sample currents of 500A, 1000A, ..., 4000A are simulated.

[0039] This involves associating and binding multiple sample distributed diagnostic coordinates, multiple sample operating current conditions, multiple sample simulated electromagnetic losses, and multiple sample simulated temperature distributions. This means establishing a one-to-one correspondence between the sample distributed diagnostic coordinates, sample operating current conditions, sample simulated electromagnetic losses, and sample simulated temperature distributions, resulting in multi-sample condition correlation mapping data. Each sample correlation mapping data includes the sample distributed diagnostic coordinates, sample operating current conditions, sample simulated electromagnetic losses, and sample simulated temperature distributions. For example, a sample distributed diagnostic coordinate might be location A1, sample operating current condition 2000A, and sample simulated electromagnetic loss 9500W / m. 3 The simulated temperature distribution of the sample was 58.5℃.

[0040] By pre-calculating and storing the physical responses of circuit breakers under various normal operating conditions, the problems of large computational load and long time consumption in real-time simulation are solved. Through association and binding, complex field data is transformed into structured data tables that are easy to retrieve and compare, ensuring that there are corresponding benchmark data for all possible operating states from no-load to overload, which greatly improves the robustness and applicability of the diagnostic system.

[0041] Furthermore, this application also includes the following steps: after limiting the current scanning range constraint based on the historical typical operating conditions of the circuit breaker, the scanning step size density gradient configuration of the operating current condition setting is performed according to the historical load frequency distribution.

[0042] Specifically, this involves acquiring historical typical operating conditions of the circuit breaker, i.e., a representative set of operating current data that actually occurred during the circuit breaker's long-term operation, including different current loads, operating environments, and fault conditions. By analyzing these historical typical operating conditions, a reasonable current scanning range is determined, i.e., a narrowed current scanning range constraint. In other words, based on publicly available historical typical conditions, the previously broad theoretical current scanning range set based on rated parameters is narrowed to a narrower, more effective current range that is closer to actual operation. This eliminates the need for simulations of extreme no-load and overload conditions that will never occur, saving significant computational resources.

[0043] Based on historical typical operating conditions, the historical load frequency distribution is determined, showing the frequency or probability of circuit breaker occurrence in different current ranges. The load frequency distribution can identify which current values ​​occur more frequently and which current values ​​are less frequently loaded in actual operation. By analyzing historical load data, different current load conditions are set, thereby configuring a gradient of scan step size density. For load ranges with high occurrence frequency, a denser scan step size is configured to ensure extremely high accuracy and resolution of the benchmark database within these critical areas. For ranges with low occurrence frequency, such as low-load and high-load segments, a sparser scan step size is configured. In other words, smaller step sizes and denser sample points are set in frequently operating current ranges to obtain higher resolution; larger step sizes and sparser sample points are set in less frequently operating current ranges.

[0044] For example, the operating current data of the circuit breaker over the past 12 months was retrieved and analyzed, yielding the following results: historical operating current range: 850A to 2750A; historical load frequency distribution: 35% frequency in the 1500-2000A range; 30% frequency in the 2000-2500A range; 15% frequency in the 1000-1500A range; and a combined 20% frequency in the 850-1000A and 2500-2750A ranges. The current scanning range was then narrowed from 0-4000A to 500-3000A. The core high-density area (1500-2500A) has a step size of 100A, with sample points set at 1500, 1600, 1700, 1800, 1900, 2000, 2100, 2200, 2300, 2400, and 2500A, for a total of 11 points. The secondary medium-density area (1000-1500A, 2500-3000A) has a step size of 250A, with sample points set at 1000, 1250, 1500A and 2500, 2750, and 3000A. Note that 1500A and 2500A are already included, so 4 new points are actually added. The edge low-density area (500-1000A) has a step size of 500A, with sample points set at 500 and 1000A. 1000A is already included, so 1 new point is actually added. Before optimization, the scan was performed uniformly within the range of 0-4000A, with 9 points (500, 1000, 1500, 2000, 2500, 3000, 3150, 3500, 4000A). After optimization, the scan was performed in a gradient manner within the range of 500-3000A, with a total of 16 sample points. Among them, 11 high-precision points were densely distributed in the core interval of 1500-2500A, which is the most frequently used range.

[0045] By setting a gradient configuration for the scanning step size density based on the historical load frequency distribution, simulation efficiency is improved while ensuring high-precision simulation. More detailed simulations are possible for frequently occurring operating conditions; while for rare high-load conditions, a larger step size reduces the computational load, allowing the simulation results to cover most of the circuit breaker's operating conditions, thus improving both simulation accuracy and computational efficiency.

[0046] The real-time operating current is obtained through the Hall sensor built into the circuit breaker.

[0047] Specifically, the real-time operating current is acquired through a Hall effect sensor embedded in the circuit breaker. The Hall effect sensor operates based on the Hall effect principle: when a current-carrying conductor is placed in a magnetic field, a potential difference, or Hall voltage, is generated in a direction perpendicular to both the current and the magnetic field. By sensing the magnetic field generated by the main circuit current, the current value is measured non-contactly. Its greatest advantage is its electrical isolation from the main circuit, ensuring safety and reliability, and its ability to measure both DC and AC currents with a wide bandwidth.

[0048] Hall effect sensors are installed in the current path of a circuit breaker, typically around the current conductor. The sensor detects the magnetic field generated by the current and converts it into a voltage signal proportional to the current magnitude through the Hall effect. During normal operation of the circuit breaker, the Hall effect sensor continuously measures the current. Real-time operating current refers to the instantaneous current value flowing through the main circuit when the circuit breaker is normally closed and conducting; it is a continuously changing analog quantity, appearing as a sinusoidal waveform in AC systems.

[0049] The non-contact infrared thermal imager is driven to collect the real-time temperature distribution of the circuit breaker in a real-time distributed diagnostic coordinate system.

[0050] Specifically, it drives a non-contact infrared thermal imager to monitor the temperature distribution of various components of a circuit breaker in real time. A non-contact infrared thermal imager is a measuring device that detects the infrared energy radiated outward from the surface of an object and converts it into a temperature value and a visualized thermal image. Non-contact means that the temperature of an object can be measured without direct contact, making it particularly suitable for high-temperature environments or devices that cannot be directly touched.

[0051] Configure and install a non-contact infrared thermal imager, ensuring it covers the entire operating area of ​​the circuit breaker, especially critical components such as electrodes, contacts, and the casing. Determine the diagnostic coordinates of each component of the circuit breaker and ensure the infrared thermal imager's temperature monitoring corresponds to these coordinates. Once activated, the non-contact infrared thermal imager automatically adjusts its focus and exposure to acquire an infrared thermal image encompassing the entire target area of ​​the circuit breaker, including the coordinates of each image and its corresponding temperature value.

[0052] Real-time distributed diagnostic coordinates are used to spatially divide and locate equipment or systems, marking the position coordinates of different components or areas, including the real-time temperature monitoring positions of different components of a circuit breaker. Real-time temperature distribution refers to the temperature distribution status of various parts during actual operation. Using pre-defined coordinate system transformation relationships, the real-time distributed diagnostic coordinates are accurately mapped to the corresponding pixel positions of the real-time thermal image. For example, simulating coordinate 1, pixel (155, 320) in the thermal image reads a temperature of 67.8℃; simulating coordinate 2, pixel (120, 410) in the thermal image reads a temperature of 59.3℃.

[0053] Using the real-time operating current and real-time distributed diagnostic coordinates as two-dimensional search conditions, target-related operating condition mapping data is retrieved from the benchmark database.

[0054] Furthermore, this application also includes the following steps: using the real-time operating current as a primary index to traverse multiple sample operating condition currents in the benchmark database, and filtering and outputting a first sample associated operating condition mapping data group; using the real-time distributed diagnostic coordinates as a secondary index, traversing N sample distributed diagnostic coordinates in the first sample associated operating condition mapping data group to solve for spatial neighborhood deviation, and obtaining N spatial proximity values; according to the descending order of the N spatial proximity values, filtering and retrieving the target associated operating condition mapping data in the first sample associated operating condition mapping data group.

[0055] Specifically, the real-time operating current is used as a primary index for the first traversal of the benchmark database. This traverses multiple sample operating currents within the sample operating condition association mapping data of the benchmark database to obtain a matching first sample association operating condition mapping data group. By finding the closest value, all sample currents that are close to the real-time operating current are selected, and the sample operating condition association mapping data corresponding to these currents are extracted to form the first sample association operating condition mapping data group.

[0056] Using real-time distributed diagnostic coordinates as a secondary index, the data is traversed within the first sample associated working condition mapping data set. Since the real-time distributed diagnostic coordinates obtained by mapping the coordinate grid of the simulation model to the real-time infrared image cannot achieve absolute pixel-level alignment, there will always be slight spatial positional deviations. Within the first sample associated working condition mapping data set, N sample distributed diagnostic coordinates are traversed, where N is a positive integer greater than or equal to 1. For each real-time coordinate point in the N sample distributed diagnostic coordinates, its spatial deviation from the real-time distributed diagnostic coordinates is calculated, resulting in N spatial proximity values. The spatial proximity value is a quantitative index obtained by mathematically processing the spatial neighborhood deviation, used to represent the closeness between two spatial points. A smaller deviation value generally indicates a higher proximity value. For example, the Euclidean distance between sample coordinates S1(155,320) and P_real(156,322) is 2.24 pixels, and the Euclidean distance between sample coordinates S2(160,325) and P_real(156,322) is 5 pixels. The proximity of S1 is 1 / (1+2.24), which is approximately 0.31, and the proximity of S2 is 1 / (1+5), which is approximately 0.17.

[0057] The calculated N spatial proximity values ​​are sorted in descending order. Based on this descending order, the data in the first sample associated operating condition mapping data group that is closest to the real-time coordinates is selected as the target associated operating condition mapping data. For example, for the aforementioned proximity between S1 and S2, the sample operating condition associated mapping data corresponding to the higher S1 coordinate point is selected as the target associated operating condition mapping data. By using real-time current as a primary index and real-time distributed diagnostic coordinates as a secondary index, combined with the calculation of spatial proximity values, the operating condition data most relevant to the real-time operating status is quickly located from the benchmark database, helping to rapidly identify and diagnose the fault location or abnormal area of ​​the circuit breaker.

[0058] The target simulation temperature is retrieved from the target-related working condition mapping data and compared with the real-time temperature distribution at the pixel level to locate the temperature deviation exceeding the threshold region.

[0059] Specifically, the target simulation temperature is retrieved from the target associated operating condition mapping data. This involves selecting the sample simulation temperature distribution corresponding to the target associated operating condition mapping data from multiple sample operating condition mapping data sets as the target simulation temperature. The target simulation temperature is then compared with the actual temperature at the corresponding location in the real-time temperature distribution at the pixel level. This involves calculating the temperature deviation at each diagnostic coordinate point. Pixel-level deviation comparison means comparing two sets of temperature data pixel by pixel, where each pixel represents the temperature value at a specific location on the circuit breaker component, performing a precise comparison point by point.

[0060] A temperature deviation threshold is set. For each pixel, the difference between the real-time temperature and the simulated temperature is calculated. If the difference exceeds the temperature deviation threshold, the area is considered to have a temperature deviation, thus locating the temperature deviation exceeding the threshold region. The temperature deviation exceeding the threshold region includes all diagnostic coordinate points whose temperature deviation exceeds the preset threshold, forming a continuous or discontinuous set in space, which determines the abnormal heating area on the device surface. For example, if the temperature deviation of pixel 1 in region 1 is 17.4℃, the temperature deviation of pixel 8 in region 2 is 20.9℃, and the temperature deviation of pixel 9 in region 2 is 16.0℃, assuming the set temperature deviation threshold for region 1 is 10℃ and the temperature deviation threshold for region 2 is 20℃, then the temperature deviation exceeding the threshold region includes pixel 1 in region 1 and pixel 8 in region 2.

[0061] By retrieving the target simulated temperature from the benchmark database and comparing it with the real-time temperature distribution at the pixel level, high-precision temperature anomaly detection can be achieved. This not only detects temperature anomalies in circuit breakers but also accurately locates fault areas.

[0062] Based on the temperature deviation exceeding the threshold region, the parameters of the three-dimensional electromagnetic field simulation model are retrospectively adjusted, and the root cause of the fault is output.

[0063] Furthermore, this application also includes the following steps: retrieving P associated physical parameter types limited to the temperature deviation exceeding the threshold region from the device basic skeleton; performing iterative inversion parameter tuning of the P associated physical parameter types in the three-dimensional electromagnetic field simulation model until the temperature distribution of the three-dimensional electromagnetic field simulation model reproduces the real-time temperature distribution, and outputting the degradation amount of P parameters; locally calling the P reference initial parameter values ​​of the P associated physical parameter types; mapping and comparing the degradation amount of P parameters and the P reference initial parameter values ​​to perform fault location, and outputting the root cause of the fault.

[0064] Specifically, based on the spatial location of the temperature deviation exceeding the threshold region, P associated physical parameter types corresponding to these regions are retrieved from the circuit breaker's basic device skeleton. These P associated physical parameter types are physical parameters related to the temperature deviation exceeding the threshold region; these parameters are crucial for equipment performance and fault diagnosis, and include current, voltage, material thermal conductivity, electromagnetic loss, etc. P is a positive integer greater than or equal to 1. For example, assuming the temperature deviation exceeding the threshold region is located in the circuit breaker's electrode region, the P associated physical parameter types would include current, electromagnetic loss, and material thermal conductivity, etc.

[0065] P associated physical parameter types are input into a 3D electromagnetic field simulation model for simulation calculation to obtain the simulated temperature distribution. The simulated temperature distribution is then compared to the real-time temperature distribution to calculate the deviation. If the deviation is large, the values ​​of the associated physical parameter types are adjusted, and the simulation is run again. This process is repeated until the difference between the simulated and real-time temperature distributions is minimized. Iterative inversion parameter tuning is an automated optimization process. In the 3D electromagnetic field simulation model, the values ​​of the above P associated physical parameter types are repeatedly adjusted, and then the fast simulation is rerun to observe the results. When the overall difference between the temperature distribution calculated by the simulation model and the actual temperature distribution measured by the infrared thermal imager is minimized after parameter adjustment, the P parameter degradation amounts are obtained. The P parameter degradation amounts are the changes in the P associated physical parameter types relative to the initial state. For example, the contact resistivity increases by 150%.

[0066] The process involves calling P baseline initial parameter values ​​for P associated physical parameter types. These values ​​represent the device's initial state or the parameter values ​​defined during the design phase, signifying its healthy and new state. The degradation amounts of the P parameters are then compared to the P baseline initial parameter values. This comparison, where the degradation amount of each physical parameter is compared to its initial value, helps determine the root cause of the fault and identifies which physical parameters' changes most directly affect the device's failure. For example, overheating in the electrode area might be due to excessive current leading to increased electromagnetic losses, which in turn causes abnormal temperatures in that area.

[0067] By mapping and comparing, abstract overheated areas are transformed into specific, quantified reports of physical parameter degradation. Through iterative inversion and parameter tuning processes, the root cause of the fault is identified, providing accurate fault location information.

[0068] Based on the root cause of the fault and the temperature deviation exceeding the threshold, the fault is determined, and the real-time fault type and alternative maintenance strategies are output.

[0069] Furthermore, this application also includes the following steps: calculating the overheating distribution morphology attribute based on the spatial contour parameters of the temperature deviation exceeding the threshold region; inputting the overheating distribution morphology attribute and the root cause of the fault into a fault decision tree for matching and outputting the real-time fault type; using the temperature deviation exceeding the threshold region as a spatial constraint, performing maintenance strategy matching based on the real-time fault type, and outputting the alternative maintenance strategy.

[0070] Specifically, based on the spatial contour parameters of the temperature deviation exceeding the threshold region—that is, the spatial characteristics and distribution of this region, including its geometry, location, and size—the overheating distribution morphology is calculated. If the region exhibits linear overheating, heat may accumulate along a specific direction; if it is area overheating, it may be due to poor heat dissipation in localized components. The overheating distribution morphology refers to the heat distribution characteristics caused by excessively high temperatures within the temperature deviation exceeding the threshold region, including the heat distribution pattern, the location of the heat source, and the uniformity of temperature distribution. By analyzing the overheating distribution morphology, it is possible to determine whether the overheating is caused by a component malfunction or abnormal operating conditions.

[0071] The overheating distribution morphology attributes and root causes are input into the fault decision tree. The fault decision tree, through layer-by-layer judgment, combines temperature, morphology attributes, and other parameters to ultimately determine the fault type. The fault decision tree makes judgments according to rules; for example, if the root cause is a significant increase in contact resistivity, and the morphology is localized point overheating, then the fault type is contact surface ablation. The fault decision tree is a pre-defined logical judgment flowchart built based on expert knowledge and historical cases. Using overheating distribution morphology attributes and root causes as input, it outputs a specific fault conclusion through a series of yes / no judgments. By matching the fault decision tree, the real-time fault type and the circuit breaker's fault diagnosis conclusion are obtained, representing the type of fault problem the equipment is currently encountering, such as excessive temperature or abnormal electromagnetic loss.

[0072] Using the temperature deviation exceeding the threshold area as a spatial constraint, and based on the real-time fault type, the maintenance strategy database is searched to obtain alternative maintenance strategies. The spatial constraint ensures that the recommended strategy is specific to the operation of a particular component. For example, if the fault area is the electrode region and annular overheating occurs, special cooling measures may be needed to alleviate the temperature. Based on the real-time fault type, multiple maintenance strategies may be proposed, providing different solutions for different temperature distributions and fault causes. Alternative maintenance strategies are one or more feasible maintenance plans, operating procedures, and safety precautions generated from the maintenance knowledge base based on the real-time fault type and spatial constraints.

[0073] By calculating the spatial profile parameters of the temperature deviation exceeding the threshold region and analyzing the overheating distribution pattern, the characteristics of the overheated region are determined, and the specific root cause of the fault is inferred. This information is then input into a fault decision tree to determine the fault type, avoiding the subjectivity and errors inherent in manual diagnosis. Based on the fault type and the spatial constraints of the overheated region, appropriate maintenance strategies are matched, which not only improves the accuracy of fault diagnosis but also enables timely and effective repair measures, reducing downtime, lowering the risk of equipment damage, and thus improving equipment reliability and safety.

[0074] Furthermore, this application also includes the following steps: if the real-time fault type involves live operation, then add dynamic safety verification rules to the alternative maintenance strategy and output a modified maintenance strategy.

[0075] Specifically, real-time fault types refer to the fault types of the circuit breaker, such as current overload, overheating, and abnormal electromagnetic loss. Determining whether the fault type involves live-line operation determines whether additional dynamic safety verification rules are needed. Live-line operation refers to maintenance, adjustment, or operation performed while the circuit breaker is in operation or the power supply is not disconnected. Live-line operation typically carries high risks and requires operators to take strict safety measures. If the fault type does not involve live-line operation, no additional safety verification rules are required.

[0076] If the real-time fault type involves live operation, a set of dynamic safety verification rules is automatically added. Dynamic safety verification rules are a real-time verification mechanism to ensure operational safety during live operations. This includes real-time monitoring of parameters such as current, voltage, and temperature to ensure that operators are not affected by electrical or other safety risks during maintenance. For example, during operation, real-time monitoring ensures that the current does not exceed the safe range to prevent electric shock or equipment damage caused by excessive current; verifies that the voltage meets safety standards to ensure it does not pose a danger to operators; monitors the temperature of the operating area in real-time to prevent electrical fires and other safety hazards caused by overheating of equipment; and isolates and protects the maintenance area to ensure that operators do not come into direct contact with live parts.

[0077] According to the dynamic safety verification rules, the alternative maintenance strategies are modified to ensure that all operational steps meet safety requirements, resulting in a revised maintenance strategy. For example, suppose a fault is diagnosed as a loose bolt connection at the C-phase terminal. The initially generated alternative maintenance strategy includes tightening the C-phase terminal bolt with an insulated wrench while the circuit is live. Since the real-time fault type is clearly live operation, dynamic safety verification is initiated. The real-time current is 1200A, and the voltage level is 110kV. The rule requires that the distance between the operator and the live conductor be ≥1.5 meters, and the verification result is passed. The terminal location can be operated from a safe distance using an insulated rod. The meteorological API is called to obtain a real-time wind speed of 10.5 m / s, approximately level 5. The rule requires that the wind speed be ≤8.0 m / s when performing delicate live-line work at high altitudes, and the verification result is failed. Due to the failure of the wind speed rule verification, the live tightening strategy is automatically rejected. A power outage is immediately requested, and the C-phase terminal bolt tightening operation is performed after the wind speed drops below 8.0 m / s. A warning was issued: the current wind speed is 10.5 m / s, exceeding the safety limit for live-line work. If live-line work is absolutely necessary, an insulated aerial work platform must be used, and a specific wind protection plan must be developed; the risk is extremely high. By adding dynamic safety verification rules during live-line operations, the safety of the operation is effectively ensured, preventing electrical accidents caused by overload, abnormal voltage, overheating, and other problems.

[0078] In summary, the circuit breaker fault diagnosis method based on simulation models provided in this application has the following technical advantages: A baseline database is constructed by pre-constructing a three-dimensional electromagnetic field simulation model and a temperature field simulation model of the circuit breaker; coupling the three-dimensional electromagnetic field simulation model and the temperature field simulation model to output multiple sample operating condition correlation mapping data; acquiring the real-time operating current through the circuit breaker's built-in Hall sensor; driving a non-contact infrared thermal imager to acquire the real-time temperature distribution of the circuit breaker in real-time distributed diagnostic coordinates; using the real-time operating current and real-time distributed diagnostic coordinates as two-dimensional search conditions to retrieve target correlation operating condition mapping data from the baseline database; retrieving the target simulation temperature from the target correlation operating condition mapping data and comparing it with the real-time temperature distribution at the pixel level to locate the temperature deviation exceeding the threshold region; performing backtracking parameter tuning of the three-dimensional electromagnetic field simulation model based on the temperature deviation exceeding the threshold region to output the root cause of the fault; and determining the fault based on the root cause of the fault and the temperature deviation exceeding the threshold region to output the real-time fault type and alternative maintenance strategies. In other words, by constructing a three-dimensional electromagnetic field simulation model and a temperature field simulation model and performing coupled simulation, the simulation efficiency is improved; real-time operating current and real-time temperature distribution are obtained, target-related operating condition mapping data are retrieved from the benchmark database, and the real-time temperature distribution is compared with the simulation prediction temperature. If the deviation exceeds the threshold, it is determined that the circuit breaker has a local overheating fault. Combined with the results of backtracking parameter tuning, the root cause of the fault is determined, the fault type is output, and alternative maintenance strategies are given, thereby improving the accuracy and efficiency of circuit breaker fault diagnosis, reducing the risk of equipment damage, optimizing maintenance resources, and reducing downtime due to faults.

[0079] Example 2: Based on the same inventive concept as the circuit breaker fault diagnosis method based on simulation models in Example 1, this application also provides a circuit breaker fault diagnosis system based on simulation models. Please refer to the appendix. Figure 2 The circuit breaker fault diagnosis system based on the simulation model includes: The model pre-construction module 11 is used to pre-construct a three-dimensional electromagnetic field simulation model and a temperature field simulation model of the circuit breaker; the coupled simulation module 12 is used to perform coupled simulation on the three-dimensional electromagnetic field simulation model and the temperature field simulation model, output multiple sample operating condition correlation mapping data, and construct a benchmark database; the current acquisition module 13 is used to acquire the real-time operating current through the Hall sensor built into the circuit breaker; the temperature acquisition module 14 is used to drive a non-contact infrared thermal imager to acquire the real-time temperature distribution of the circuit breaker in real-time distributed diagnostic coordinates; and the data retrieval module 15 is used to retrieve the real-time operating current. Using real-time distributed diagnostic coordinates as a two-dimensional retrieval condition, the target-related operating condition mapping data is retrieved from the benchmark database; the deviation comparison module 16 is used to retrieve the target simulation temperature from the target-related operating condition mapping data, compare it with the real-time temperature distribution at the pixel level, and locate the temperature deviation exceeding the threshold region; the backtracking parameter tuning module 17 is used to perform backtracking parameter tuning of the three-dimensional electromagnetic field simulation model based on the temperature deviation exceeding the threshold region, and output the root cause of the fault; the fault determination module 18 is used to determine the fault based on the root cause of the fault and the temperature deviation exceeding the threshold region, and output the real-time fault type and alternative maintenance strategies.

[0080] Furthermore, the model pre-construction module 11 in the circuit breaker fault diagnosis system based on the simulation model is also used to: construct a basic skeleton of the device based on the three-dimensional structural data of the circuit breaker; initialize the basic skeleton of the device with the structural material properties and operating condition range as boundary conditions to generate the three-dimensional electromagnetic field simulation model; after inputting the operating current, perform electromagnetic field distribution simulation in the three-dimensional electromagnetic field simulation model and output distributed electromagnetic loss; use the distributed electromagnetic loss as a heat source to input the temperature field simulation framework, perform temperature field distribution simulation, and establish the temperature field simulation model.

[0081] Furthermore, the coupled simulation module 12 in the circuit breaker fault diagnosis system based on the simulation model is also used for: calling rated parameters online according to the circuit breaker ID, and using the rated parameters as current scanning range constraints to set multiple sample operating current conditions; setting environmental boundary conditions according to the application scenario of the circuit breaker; using the environmental boundary conditions as temperature field boundary parameters, inputting the multiple sample operating current conditions in ascending order to the three-dimensional electromagnetic field simulation model to solve Maxwell's equations, and outputting multiple sample simulated electromagnetic losses; inputting the multiple sample simulated electromagnetic losses as spatial heat sources into the temperature field simulation model to perform heat conduction solutions, and outputting multiple sample simulated temperature distributions, wherein the multiple sample simulated temperature distributions carry multiple sample distributed diagnostic coordinate identifiers; associating and binding the multiple sample distributed diagnostic coordinates, multiple sample operating current conditions, multiple sample simulated electromagnetic losses, and multiple sample simulated temperature distributions to generate multiple sample condition association mapping data.

[0082] Furthermore, the coupled simulation module 12 in the circuit breaker fault diagnosis system based on the simulation model is also used for: each sample associated operating condition mapping data includes sample distributed diagnostic coordinates, sample operating current conditions, sample simulated electromagnetic losses, and sample simulated temperature distribution.

[0083] Furthermore, the coupled simulation module 12 in the circuit breaker fault diagnosis system based on the simulation model is also used to: after limiting the current scanning range constraint according to the historical typical operating conditions of the circuit breaker, perform gradient configuration of the scanning step size density of the operating current condition setting according to the historical load frequency distribution.

[0084] Furthermore, the data retrieval module 15 in the circuit breaker fault diagnosis system based on the simulation model is also used to: use the real-time operating current as a primary index to traverse multiple sample operating condition currents in the benchmark database, and filter and output a first sample associated operating condition mapping data group; use the real-time distributed diagnostic coordinates as a secondary index to traverse N sample distributed diagnostic coordinates in the first sample associated operating condition mapping data group to solve for spatial neighborhood deviation, and obtain N spatial proximity values; and according to the descending order of the N spatial proximity values, filter and retrieve the target associated operating condition mapping data in the first sample associated operating condition mapping data group.

[0085] Furthermore, the backtracking parameter tuning module 17 in the circuit breaker fault diagnosis system based on the simulation model is also used to: retrieve P related physical parameter types limited to the temperature deviation exceeding the threshold region from the device basic skeleton; perform iterative inversion parameter tuning of the P related physical parameter types in the three-dimensional electromagnetic field simulation model until the temperature distribution of the three-dimensional electromagnetic field simulation model reproduces the real-time temperature distribution, and output the degradation amount of P parameters; locally call the P reference initial parameter values ​​of the P related physical parameter types; map and compare the degradation amount of P parameters and the P reference initial parameter values ​​to perform fault location and output the root cause of the fault.

[0086] Furthermore, the fault determination module 18 in the circuit breaker fault diagnosis system based on the simulation model is also used to: calculate the overheating distribution morphology attribute based on the spatial contour parameters of the temperature deviation exceeding the threshold region; input the overheating distribution morphology attribute and the fault root cause into the fault decision tree for matching and outputting the real-time fault type; and perform maintenance strategy matching based on the real-time fault type using the temperature deviation exceeding the threshold region as a spatial constraint, and output the alternative maintenance strategy.

[0087] Furthermore, the fault determination module 18 in the circuit breaker fault diagnosis system based on the simulation model is also used to: if the real-time fault type involves live operation, add dynamic safety verification rules to the alternative maintenance strategy and output the corrected maintenance strategy.

[0088] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Figure 1 The circuit breaker fault diagnosis method and specific examples based on simulation models in Example 1 are also applicable to the circuit breaker fault diagnosis system based on simulation models in this example. Through the foregoing detailed description of the circuit breaker fault diagnosis method based on simulation models, those skilled in the art can clearly understand the circuit breaker fault diagnosis system based on simulation models in this example. Therefore, for the sake of brevity, it will not be described in detail here.

[0089] The above description of the disclosed embodiments enables those skilled in the art to make or use this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0090] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of this application and its equivalents, this application also intends to include such modifications and variations.

Claims

1. A circuit breaker fault diagnosis method based on a simulation model, characterized in that, include: Pre-constructed 3D electromagnetic field simulation model and temperature field simulation model of circuit breaker; By coupling the three-dimensional electromagnetic field simulation model and the temperature field simulation model, multiple sample working condition correlation mapping data are output to construct a benchmark database. The real-time operating current is obtained through the Hall sensor built into the circuit breaker; The non-contact infrared thermal imager is driven to acquire the real-time temperature distribution of the circuit breaker in a real-time distributed diagnostic coordinate system. Using the real-time operating current and real-time distributed diagnostic coordinates as two-dimensional search conditions, target-related operating condition mapping data is retrieved from the benchmark database. The target simulation temperature is retrieved from the target associated working condition mapping data and compared with the real-time temperature distribution at the pixel level to locate the temperature deviation exceeding the threshold area. Based on the temperature deviation exceeding the threshold region, the parameters of the three-dimensional electromagnetic field simulation model are retrospectively adjusted, and the root cause of the fault is output. Based on the root cause of the fault and the temperature deviation exceeding the threshold area, the fault is determined, and the real-time fault type and alternative maintenance strategies are output. The method involves coupling the three-dimensional electromagnetic field simulation model and the temperature field simulation model to output multiple sample working condition correlation mapping data and construct a benchmark database. Based on the circuit breaker ID, the rated parameters are called through the network, and the rated parameters are used as constraints for the current scanning range to set multiple sample operating current conditions. Set environmental boundary conditions based on the application scenario of the circuit breaker; Using the environmental boundary conditions as the temperature field boundary parameters, the multiple sample operating current conditions are input in ascending order to the three-dimensional electromagnetic field simulation model to solve Maxwell's equations, and the simulated electromagnetic losses of multiple samples are output. The electromagnetic loss of the multiple samples is used as a space heat source and input into the temperature field simulation model to perform heat conduction solution, and the multiple sample simulated temperature distributions are output, wherein the multiple sample simulated temperature distributions are labeled with multiple sample distributed diagnostic coordinates. The distributed diagnostic coordinates of the multiple samples, the operating current conditions of the multiple samples, the simulated electromagnetic losses of the multiple samples, and the simulated temperature distribution of the multiple samples are associated and bound to generate the associated mapping data of the multiple sample operating conditions.

2. The circuit breaker fault diagnosis method based on a simulation model as described in claim 1, characterized in that, The method for pre-constructing three-dimensional electromagnetic field simulation models and temperature field simulation models of circuit breakers includes: The basic framework of the device is constructed based on the three-dimensional structural data of the circuit breaker; The structural material properties and operating condition range are used as boundary conditions to initialize the basic skeleton of the device, thereby generating the three-dimensional electromagnetic field simulation model. After inputting the operating current, the electromagnetic field distribution is simulated in the three-dimensional electromagnetic field simulation model, and the distributed electromagnetic loss is output. Using the distributed electromagnetic loss as a heat source input temperature field simulation framework, the temperature field distribution is simulated, and the temperature field simulation model is established.

3. The circuit breaker fault diagnosis method based on a simulation model as described in claim 2, characterized in that, The method involves retrospectively adjusting the parameters of the three-dimensional electromagnetic field simulation model based on the temperature deviation exceeding the threshold region, and outputting the root cause of the fault. Retrieve P associated physical parameter types that are limited to the temperature deviation threshold region from the device's basic framework; In the three-dimensional electromagnetic field simulation model, iterative inversion and parameter tuning of the P associated physical parameter types are performed until the temperature distribution of the three-dimensional electromagnetic field simulation model reproduces the real-time temperature distribution, and the degradation of the P parameters is output. Locally invoke the P baseline initial parameter values ​​of the P associated physical parameter types; By mapping and comparing the degradation values ​​of the P parameters with the initial values ​​of the P reference parameters, fault location is performed, and the root cause of the fault is output.

4. The circuit breaker fault diagnosis method based on a simulation model as described in claim 3, characterized in that, The method involves determining the fault based on the root cause and the temperature deviation exceeding the threshold, outputting the real-time fault type and alternative maintenance strategies, and includes: The overheating distribution morphology attributes are calculated based on the spatial contour parameters of the temperature deviation exceeding the threshold region. The overheating distribution morphology attribute and the root cause of the fault are input into the fault decision tree for matching and output of the real-time fault type. Using the temperature deviation exceeding the threshold region as a spatial constraint, maintenance strategies are matched according to the real-time fault type, and alternative maintenance strategies are output.

5. The circuit breaker fault diagnosis method based on a simulation model as described in claim 1, characterized in that, Each sample's associated operating condition mapping data includes the sample's distributed diagnostic coordinates, sample's operating current conditions, sample's simulated electromagnetic losses, and sample's simulated temperature distribution.

6. The circuit breaker fault diagnosis method based on a simulation model as described in claim 1, characterized in that, After limiting the current scanning range based on the historical typical operating conditions of the circuit breaker, the scanning step size density gradient configuration is performed according to the historical load frequency distribution.

7. The circuit breaker fault diagnosis method based on a simulation model as described in claim 1, characterized in that, Using the real-time operating current and real-time distributed diagnostic coordinates as two-dimensional search conditions, the method retrieves target-related operating condition mapping data from the benchmark database. The real-time operating current is used as a primary index to traverse multiple sample operating condition currents in the benchmark database, and the first sample associated operating condition mapping data group is filtered and output. Using the real-time distributed diagnostic coordinates as a secondary index, the spatial neighborhood deviation is solved by traversing the N sample distributed diagnostic coordinates in the first sample associated working condition mapping data group to obtain N spatial proximity values. Based on the descending order of the N spatial proximity values, the target associated working condition mapping data is retrieved from the first sample associated working condition mapping data group.

8. The circuit breaker fault diagnosis method based on a simulation model as described in claim 7, characterized in that, If the real-time fault type involves live operation, then add dynamic safety verification rules to the alternative maintenance strategy and output a modified maintenance strategy.

9. A circuit breaker fault diagnosis system based on a simulation model, characterized in that, The steps for implementing the circuit breaker fault diagnosis method based on a simulation model according to any one of claims 1 to 8, wherein the circuit breaker fault diagnosis system based on the simulation model comprises: The model pre-building module is used to pre-build three-dimensional electromagnetic field simulation models and temperature field simulation models of circuit breakers; The coupled simulation module is used to perform coupled simulation on the three-dimensional electromagnetic field simulation model and the temperature field simulation model, output multiple sample working condition correlation mapping data, and build a benchmark database. The current acquisition module is used to acquire the real-time operating current through the Hall sensor built into the circuit breaker; The temperature acquisition module is used to drive a non-contact infrared thermal imager to acquire the real-time temperature distribution of the circuit breaker in real-time distributed diagnostic coordinates. The data retrieval module is used to retrieve target-related operating condition mapping data from the benchmark database by using the real-time operating current and real-time distributed diagnostic coordinates as two-dimensional retrieval conditions. The deviation comparison module is used to retrieve the target simulation temperature from the target associated working condition mapping data, compare it with the real-time temperature distribution at the pixel level, and locate the temperature deviation exceeding the threshold region. The backtracking parameter tuning module is used to perform backtracking parameter tuning of the three-dimensional electromagnetic field simulation model based on the temperature deviation exceeding the threshold region, and output the root cause of the fault. The fault determination module is used to determine the fault based on the root cause of the fault and the temperature deviation exceeding the threshold area, and output the real-time fault type and alternative maintenance strategies.

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