A fully-enclosed epoxy resin cast current transformer and a casting method thereof

Abstract

The application provides a fully-closed epoxy resin pouring type current transformer and a pouring method thereof, and belongs to the technical field of high-voltage electrical equipment manufacturing and advanced insulation material forming technology. The method comprises the following steps: assembling a primary winding and a secondary winding in a preset layout in the interior of a detachable shell to generate a winding assembly to be poured; conveying the winding assembly to be poured to a fully-closed pouring station through a conveying component, synchronously starting a clamping component to non-destructively fix the assembly, and forming a stable pouring cavity; and improving the integrity and compactness of resin mold filling through dynamic trajectory planning and multi-stage vacuum gradient control technology, and reducing the air wrapping and flow mark defect rate.

Description

Technical Field

[0001] This invention proposes a fully enclosed epoxy resin cast current transformer and its casting method, belonging to the field of high-voltage electrical equipment manufacturing and advanced insulation material molding technology. Background Technology

[0002] In the field of power equipment manufacturing, current transformers are key measurement and protection devices, and their insulation performance directly affects the safety of power grid operation.

[0003] Traditional oil-immersed instrument transformers are prone to oil leakage, while SF6 gas-insulated transformers face greenhouse effect limitations. Although existing epoxy resin casting processes have achieved oil-free operation, they have exposed multiple technical bottlenecks: the casting process relies on a fixed gate, which is difficult to adapt to complex winding morphologies, resulting in impeded resin flow and frequent defects such as gas entrapment and flow marks; the vacuum treatment adopts a constant mode throughout the process, which both inhibits resin flow and cannot compensate for curing shrinkage, easily forming internal voids; the natural cooling method after curing causes a mismatch in the thermal expansion coefficients of epoxy resin and metal conductors, resulting in microcracks at the interface; quality inspection relies on offline sampling, which cannot achieve full-process monitoring, and the risk of defective products entering the market is high.

[0004] Existing patented technologies mostly focus on surface solutions such as improving vacuum casting equipment or optimizing degassing processes, such as optimizing epoxy resin formulations. While these improve material performance, they do not solve the defects in the process system.

[0005] The industry urgently needs to break through the traditional static casting paradigm and build an intelligent molding system with functions such as shape self-adaptation, dynamic shrinkage compensation, stress reduction and online sensing, so as to achieve a technological leap from passive molding to active control. Summary of the Invention

[0006] This invention provides a fully enclosed epoxy resin cast current transformer and its casting method to solve the problems mentioned in the background art above: This invention proposes a casting method for a fully enclosed epoxy resin cast current transformer, the method comprising: S1. Assemble the primary winding and secondary winding in a preset layout inside the detachable housing to generate the winding assembly to be poured; transport the winding assembly to be poured to the fully enclosed pouring station through the transport component, and simultaneously start the clamping component to fix the assembly without damage to form a stable pouring cavity. S2. Based on the three-dimensional topography data of the winding assembly, the annular opening and closing casting component is driven to implement dynamic trajectory planning, so that the casting port can implement adaptive path tracking along the complex contour. Through multi-level vacuum gradient control technology, low vacuum is used to promote flow in the resin filling stage, and high vacuum is switched to enhance degassing in the curing stage, while compensating resin is injected simultaneously to offset shrinkage stress. S3. During the resin filling process, the viscosity, temperature and pressure coupling field are monitored in real time through a distributed optical fiber sensor network. When a local gas encapsulation tendency is detected, the ultrasonic vibration module is automatically triggered to perform in-situ defoaming. During the curing stage, the infrared thermal imaging system is activated to scan the interface thermal stress distribution and drive the semiconductor cooling unit to perform zoned temperature control. S4. Microwave penetration online detection technology is used to scan the resin density in real time during the curing process. When an abnormal density area is detected, the local micro-injection device is immediately activated to perform precise glue replenishment. The process parameters of the entire process are recorded simultaneously and a digital twin model is generated. The pouring trajectory and vacuum timing are continuously optimized through machine learning algorithms. S5. Based on the residual stress distribution map output by the digital twin model, laser shock strengthening treatment is applied to the finished product to generate a stress-uniform insulation structure.

[0007] This invention proposes a fully enclosed epoxy resin cast current transformer, which is used to perform the casting method described above. The current transformer includes: Component transfer module: The primary winding and secondary winding are assembled in a preset layout inside the detachable housing to generate the winding assembly to be poured; the winding assembly to be poured is transferred to the fully enclosed pouring station by the transport component, and the clamping component is activated simultaneously to fix the assembly without damage to form a stable pouring cavity; Trajectory planning module: Based on the three-dimensional topography data of the winding assembly, the annular opening and closing casting component is driven to implement dynamic trajectory planning, so that the casting port can perform adaptive path tracking along the complex contour; through multi-level vacuum gradient control technology, low vacuum is used to promote flow in the resin filling stage, and high vacuum is switched to enhance degassing in the curing stage, and compensation resin is injected simultaneously to offset shrinkage stress. Temperature control module: During the resin filling process, the viscosity, temperature and pressure coupling field are monitored in real time through a distributed optical fiber sensor network. When a local gas encapsulation tendency is detected, the ultrasonic vibration module is automatically triggered to perform in-situ defoaming. During the curing stage, the infrared thermal imaging system is activated to scan the interface thermal stress distribution and drive the semiconductor cooling unit to perform zoned temperature control. Continuous optimization module: Employs microwave penetration online detection technology to perform 100% real-time scanning of resin density during the curing process. When an abnormal density area is detected, the local micro-injection device is immediately activated to perform precise glue replenishment. Simultaneously, the entire process parameters are recorded and a digital twin model is generated. Machine learning algorithms are used to continuously optimize the pouring trajectory and vacuum timing. Strengthening module: Based on the residual stress distribution map output by the digital twin model, the finished product is subjected to laser shock strengthening treatment to generate a stress-uniform insulation structure.

[0008] The beneficial effects of this invention are as follows: Dynamic trajectory planning and multi-level vacuum gradient control technology improve the integrity and density of resin filling, reducing the rate of air entrapment and flow marks; the intelligent stress reduction system effectively alleviates the mismatch in thermal expansion coefficients at the epoxy and metal interfaces, enhancing product structural stability and reducing microcrack formation; the full-process online sensing and precise glue replenishment mechanism avoids the lag of traditional offline detection, eliminating the risk of insulation failure due to internal voids. This method can adapt to the automated casting requirements of complex winding morphologies, significantly improving production efficiency, and can continuously optimize process parameters through digital twin models, achieving an upgrade from experience-driven to data-driven manufacturing modes. Ultimately, it produces highly reliable current transformers with oil-free, gas-free, flame-retardant, and explosion-proof characteristics, providing a solid guarantee for the safe operation of the power grid. Attached Figure Description

[0009] Figure 1 This is a diagram illustrating the steps of the method described in this invention; Figure 2 This is a system module diagram of the present invention. Detailed Implementation

[0010] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0011] One embodiment of the present invention, such as Figure 1 As shown, a casting method for a fully enclosed epoxy resin cast current transformer is disclosed, the method comprising: S1. Assemble the primary winding and secondary winding in a preset layout inside the detachable housing to generate the winding assembly to be poured; transport the winding assembly to be poured to the fully enclosed pouring station through the transport component, and simultaneously start the clamping component to fix the assembly without damage to form a stable pouring cavity. S2. Based on the three-dimensional topography data of the winding assembly, the annular opening and closing casting component is driven to implement dynamic trajectory planning, so that the casting port can implement adaptive path tracking along the complex contour. Through multi-level vacuum gradient control technology, low vacuum is used to promote flow in the resin filling stage, and high vacuum is switched to enhance degassing in the curing stage, while compensating resin is injected simultaneously to offset shrinkage stress. S3. During the resin filling process, the viscosity, temperature and pressure coupling field are monitored in real time through a distributed optical fiber sensor network. When a local gas entrapment tendency is detected, the ultrasonic vibration module is automatically triggered to perform in-situ defoaming. During the curing stage, the infrared thermal imaging system is activated to scan the thermal stress distribution at the interface and drive the semiconductor cooling unit to perform zoned temperature control to eliminate microcracks at the epoxy and metal interfaces. S4. Microwave penetration online detection technology is used to scan the resin density in real time during the curing process. When an abnormal density area is detected, the local micro-injection device is immediately activated to perform precise glue replenishment. The process parameters of the entire process are recorded simultaneously and a digital twin model is generated. The pouring trajectory and vacuum timing are continuously optimized through machine learning algorithms. S5. Based on the residual stress distribution map output by the digital twin model, the finished product is subjected to laser shock strengthening treatment to generate a stress-uniform insulation structure. After the final product undergoes airtightness testing and partial discharge verification, it forms a fully enclosed epoxy resin cast current transformer with oil-free, gas-free, flame-retardant, and explosion-proof characteristics.

[0012] The working principle and effects of the above technical solution are as follows: By precisely controlling the process parameters of the entire epoxy resin casting process, the molding quality of the current transformer insulation structure is improved, as well as the stability of the product's electrical and mechanical properties. It reduces the probability of defects such as bubbles, cracks, and uneven density during resin casting, and also reduces subsequent maintenance costs. It enhances the bonding strength between the epoxy and metal interfaces, improving the overall insulation protection capability and short-circuit current withstand capability of the transformer. It reduces stress damage caused by resin shrinkage during casting, reducing the possibility of faults such as partial discharge. It avoids the problems of incomplete degassing and uneven temperature control in traditional casting processes, which lead to substandard product performance and prevent safety accidents caused by insulation defects. It can adapt to complex winding contours for precise casting, and through full-process monitoring and optimization, it achieves process closed-loop control, resulting in finished products that are oil-free, gas-free, flame-retardant, and explosion-proof, significantly improving the operational reliability and service life of the current transformer.

[0013] In one embodiment of the present invention, S1 includes: S11. Organize the assembly reference of the primary winding and the secondary winding, and nest them in the inner cavity positioning area of ​​the detachable shell according to the preset layout to generate the winding assembly to be cast. S12. Adjust the operating parameters of the carrier component and smoothly transfer the winding assembly to be poured to the designated reference position of the fully enclosed pouring station. S13. Sensing the positioning status of the winding assembly to be poured, simultaneously activating the multi-point clamping components to apply a balanced clamping force to the non-working surface of the assembly; S14. The outer contour of the adaptable winding assembly is clamped and fixed to form a sealed and gapless stable casting cavity; the sealing performance and positioning accuracy of the stable casting cavity are tested, and pre-casting station test data is generated.

[0014] The working principle and effects of the above technical solution are as follows: Completing the nested assembly of the windings according to the standard improves the assembly accuracy of the primary and secondary windings, making the winding layout within the casing more reasonable and reducing the adverse effects of assembly deviations on subsequent casting. Adjusting the parameters of the transport component and smoothly transferring the components reduces damage from impacts during transport, ensuring the integrity of the winding structure. Applying balanced clamping force at multiple points and adapting to the contour fixation enhances the sealing effect and structural stability of the casting cavity, preventing resin leakage during casting. Performing sealing and positioning tests on the casting cavity allows for early detection of potential problems at the workstation, preventing quality issues such as material shortages and core misalignment in the cast product due to poor cavity sealing or inaccurate positioning. It also lays a good foundation for subsequent epoxy resin casting operations, improving the smoothness of the overall casting process.

[0015] In one embodiment of the present invention, S2 includes: S21. Scan the three-dimensional morphology of the winding assembly inside the stable casting cavity, collect contour coordinates and structural gap data, and generate three-dimensional morphology data of the winding. S22. The control module that transmits the three-dimensional topography data of the winding to the annular opening and closing casting component drives the component to perform dynamic trajectory planning and generate an adaptive casting path. S23. The annular opening and closing casting component moves along the adaptive casting path to achieve adaptive path tracking of the casting port to the complex contour of the winding assembly. S24. Activate multi-stage vacuum gradient control technology to adjust the vacuum system to a low vacuum range during the resin filling stage to promote the flow of epoxy resin melt within the cavity. S25. After the resin filling is completed, switch to the curing stage, adjust the vacuum system to the high vacuum range to enhance the degassing inside the resin, and simultaneously inject compensating resin to offset the shrinkage stress during the curing process.

[0016] The working principle and effects of the above technical solution are as follows: Scanning the three-dimensional morphology of the winding assembly and collecting accurate data improves the fit of the casting trajectory planning, allowing the casting path to fully adapt to the complex contours of the winding and reducing the occurrence of incomplete or accumulated resin casting. Driving the casting component to perform dynamic trajectory planning and achieve adaptive path tracking improves the uniformity of epoxy resin casting and reduces the probability of insufficient resin in local areas of the winding. The phased control of multi-level vacuum gradients enhances the smoothness of resin filling and the thoroughness of degassing, avoiding air bubble defects formed inside the resin. Injecting compensating resin during the curing stage effectively offsets the stress generated by resin shrinkage, reducing the problems of insulation structure cracking and deformation, and preventing the reduction of transformer insulation performance due to shrinkage stress. This process not only allows epoxy resin to fully fill the gaps in the winding, but also ensures the internal structure of the casting body is dense, significantly improving the molding quality of the transformer insulation structure and the overall electrical performance.

[0017] In one embodiment of the present invention, step S22 includes: S221. Transmit the three-dimensional morphological data of the winding to the control module of the annular opening and closing casting component to generate basic data for component operation; S222: The control module analyzes the basic operating data of the components, extracts the contour features and gap distribution information of the winding components, and generates basic parameters for trajectory planning. S223. Calculate the motion nodes and running speed of the pouring gate based on the basic parameters of trajectory planning, and generate a preliminary pouring trajectory; S224. The initial pouring trajectory is smoothed and the nodes are optimized to generate a dynamic trajectory scheme that adapts to the winding profile. The annular opening and closing pouring component receives the dynamic trajectory scheme, performs trajectory planning calculations, and generates an adaptive pouring path.

[0018] The working principle and effects of the above technical solution are as follows: transmitting the three-dimensional shape data of the winding to the control module to generate basic operating data improves the accuracy of the original data for pouring trajectory planning and reduces deviations in subsequent trajectory calculations. Parsing the basic data to extract contour and gap information to generate planning parameters allows the trajectory planning to fit the actual winding structure, reducing the possibility of misalignment between the pouring path and the winding contour. Calculating motion nodes and speeds to generate a preliminary pouring trajectory clarifies the movement rhythm of the pouring nozzle and enhances the trajectory's adaptability to the complex winding structure. Smoothing and node optimization of the preliminary trajectory generates a dynamic trajectory scheme, which is then used to generate an adaptive pouring path. This avoids stuttering and sudden stops during pouring nozzle movement and prevents resin accumulation or leakage due to abrupt path changes. This process ensures that the pouring path perfectly matches the complex contour of the winding and that the movement of the pouring nozzle is smoother, significantly improving the uniformity and accuracy of epoxy resin pouring.

[0019] In one embodiment of the present invention, S223 includes: Extract the core dimension data from the basic parameters of trajectory planning to generate basic information for pouring gate calculation; The coordinates of the basic information of the pouring gate are calibrated and the rate is calculated to generate the initial coordinates of the moving nodes. By adjusting the spacing and connection angle of the motion nodes in conjunction with the contour curvature of the winding assembly, the motion nodes of the pouring gate are generated. Based on the distribution density of the moving nodes, the corresponding pouring gate running speed is matched to generate speed allocation data; the pouring gate moving nodes and speed allocation data are integrated to generate a preliminary pouring trajectory.

[0020] The working principle and effects of the above technical solution are as follows: Extracting core dimension data of trajectory planning basic parameters to generate computational basic information improves the accuracy of the pouring gate motion calculation and reduces the interference of invalid data on trajectory planning. Coordinate calibration and rate calculation of the computational basic information generate initial coordinates, enabling more accurate positioning of the pouring gate motion nodes and reducing the deviation range of subsequent trajectory adjustments. Combining the winding contour curvature with adjusting the node spacing and connection angle to generate motion nodes enhances the fit of nodes to the complex contour of the winding, avoiding the problem of motion nodes becoming disconnected from the winding contour. Matching the pouring gate running rate with the node distribution density to generate rate allocation data allows the movement rhythm of the pouring gate to adapt to contour changes, reducing accumulation and material shortages caused by excessively fast or slow resin pouring. Integrating the motion node and rate allocation data to generate a preliminary pouring trajectory ensures that the trajectory fully matches the structural characteristics of the winding and makes the movement of the pouring gate more regular, laying a solid foundation for subsequent trajectory optimization and improving the smoothness and accuracy of the overall pouring operation.

[0021] In one embodiment of the present invention, S3 includes: S31. During the resin filling process, a distributed fiber optic sensor network is activated to monitor the viscosity, temperature and pressure of the epoxy resin melt in the cavity in real time, and generate coupled field monitoring data. S32. Continuously analyze the coupled field monitoring data, capture the local gas entrainment tendency characteristics during the melt flow process, and generate gas entrainment monitoring signals; S33. Upon receiving the air-encapsulation monitoring signal, the ultrasonic vibration module is automatically triggered to perform in-situ high-frequency defoaming treatment on the air-encapsulation area. S34. After entering the curing stage, the infrared thermal imaging system is activated to perform a full-area thermal stress scan on the interface between epoxy and metal, generating interface thermal stress distribution data. S35. Based on the interface thermal stress distribution data, drive the semiconductor cooling unit to implement zoned temperature control in high-stress areas and eliminate the hidden danger of interface microcracks.

[0022] The working principle and effects of the above technical solution are as follows: Activating a distributed fiber optic sensor network for comprehensive monitoring during the resin filling stage improves the sensitivity to changes in melt viscosity, temperature, and pressure, allowing for more comprehensive collection of coupled field data and reducing blind spots in process parameter monitoring during casting. Continuous analysis of monitoring data and detection of entrapment tendencies allows for early detection of entrapment problems within the melt, timely generation of monitoring signals, and prevention of insulation structural defects caused by the expansion of entrapment areas. Triggering an ultrasonic vibration module for in-situ degassing enhances the timeliness and thoroughness of internal resin degassing, reducing the probability of bubbles and voids in the casting. During the curing stage, an infrared thermal imaging system scans thermal stress, accurately capturing the interface stress distribution and providing precise data for temperature control. Driving a semiconductor cooling unit for zoned temperature control effectively alleviates stress concentration at the epoxy-metal interface, reduces the generation of microcracks, and prevents a decline in the insulation performance of the transformer due to interface cracks. This ensures both the density of the internal structure of the casting and improves the stability and service life of the transformer's insulation structure.

[0023] In one embodiment of the present invention, S35 includes: S351. Analyze the interface thermal stress distribution data, extract the location and thermal stress value of high stress areas, and generate basic data for zoned temperature control. S352. Perform gradient division on the basic data of zone temperature control to generate multiple temperature control thresholds; the semiconductor refrigeration unit receives the multiple temperature control thresholds, allocates the working power of each refrigeration module, and generates zone power control instructions. S353. Each cooling module executes a zone power control command to implement differentiated temperature control in high-stress areas and generate zone temperature control effect data. S354. Dynamically fine-tune the cooling power based on regional temperature control effect data, continuously optimize the temperature field distribution, and eliminate the hidden danger of interface micro-cracks.

[0024] The working principle and effects of the above technical solution are as follows: Analyzing interface thermal stress data and extracting information on high-stress areas improves the accuracy of temperature control target positioning, making subsequent temperature regulation more targeted and reducing ineffective temperature control operations. Gradient division of the basic temperature control data and allocation of cooling module power enhances the hierarchical nature of temperature regulation, reduces temperature control deviation in high-stress areas, and avoids the problem of incomplete stress relief caused by a single temperature control mode. Differentiated temperature control by each cooling module results in a more uniform temperature field distribution at the epoxy-metal interface, reducing localized thermal stress concentration and alleviating deformation differences between interfaces. Dynamically fine-tuning the cooling power based on the temperature control effect continuously optimizes the temperature field state, completely eliminating the potential for micro-cracks at the interface, and preventing the degradation of transformer insulation performance due to micro-cracks. This ensures the integrity of the transformer insulation structure, improves the overall electrical performance and operational stability of the product, and extends the service life of the equipment.

[0025] In one embodiment of the present invention, S352 includes: Extract the thermal stress value range from the basic data of zoned temperature control to generate the basis for dividing the temperature control gradient; divide the zone into multiple levels according to the thermal stress value, calibrate the temperature control critical value of each zone, and generate the initial temperature control threshold. By combining the thermal expansion properties of epoxy and metal, the initial temperature control threshold is modified to generate multiple temperature control thresholds. The semiconductor cooling unit receives multiple temperature control thresholds, matches the temperature control range corresponding to each cooling module, and generates a module power allocation coefficient. The operating power of each refrigeration module is set according to the module power allocation coefficient, and a zone power control command is generated.

[0026] The working principle and effects of the above technical solution are as follows: Extracting the thermal stress value range from the basic data of zoned temperature control generates a gradient division basis, improving the scientific nature of the temperature control gradient division and making the subsequent temperature control range setting more closely match the actual stress conditions, reducing temperature control deviations caused by blind division. Dividing the temperature control into multiple levels according to the thermal stress and calibrating the critical values ​​to generate initial temperature control thresholds enhances the hierarchical nature of temperature control, reduces the situation where temperature control in high-stress areas is inadequate, and avoids the problem that a single threshold cannot adapt to different stress areas. Combining the thermal expansion characteristics of epoxy and metal to correct the threshold and generate multiple temperature control thresholds allows the temperature control standard to be more adapted to material characteristics, reducing interface stress caused by differences in material thermal expansion. The semiconductor refrigeration unit matches the temperature control range to generate a power distribution coefficient, and then sets the operating power to generate control commands, enabling more precise power output from each refrigeration module. This achieves targeted temperature control in high-stress areas, avoids wasted refrigeration power, effectively alleviates interface thermal stress concentration, reduces micro-crack generation at the source, and improves the stability of the transformer insulation structure.

[0027] In one embodiment of the present invention, step S4 includes: S41. Start the microwave penetration online detection system to perform a 100% real-time full-area scan of the resin density of the casting during the curing process and generate resin density distribution data. S42. Analyze the resin density distribution data, identify the density abnormal area in the casting body, and generate a glue replenishment trigger signal; upon receiving the glue replenishment trigger signal, immediately start the local micro-injection device to perform precise quantitative glue replenishment to the density abnormal area. S43. Synchronously collect process parameters of the entire casting process, integrate and generate a digital twin model of the casting process, and map the solidification state and structural characteristics of the casting body; S44. Input the running data of the digital twin model into the machine learning algorithm, iteratively train and update the casting trajectory and vacuum gradient timing to generate an optimized set of process parameters.

[0028] The working principle and effects of the above technical solution are as follows: Activating the microwave detection system to scan the resin density across the entire area improves the comprehensiveness and real-time nature of density detection within the casting, allowing for rapid identification of areas with abnormal density and reducing performance risks caused by uneven density in the insulation structure. Analyzing the data and activating the micro-injection device for precise resin replenishment reduces the probability of defects such as voids and porosity in the casting, enhances the compactness of the insulation structure, and prevents a decline in the insulation performance of the current transformer due to localized density anomalies. Simultaneously collecting process parameters to generate a digital twin model accurately maps the curing state of the casting, allowing process adjustments to better align with actual production conditions. Inputting the model data into the algorithm for iterative training, updating the casting trajectory and vacuum timing, continuously optimizes the casting process and improves the accuracy and stability of subsequent casting operations. This process enables real-time detection and precise repair of casting defects and forms a production closed loop through process iteration, significantly improving the molding quality of the current transformer insulation structure and enhancing the overall electrical performance and operational reliability of the product.

[0029] In one embodiment of the present invention, S44 includes: Extract full-dimensional operational data from the digital twin model to generate a basic dataset for algorithm training; perform data cleaning and feature extraction on the basic dataset for algorithm training to generate machine learning training samples; The machine learning training samples are input into the machine learning algorithm to carry out multiple rounds of iterative training and generate a process optimization training model. The process optimization training model is used to calculate the correction parameters of the casting trajectory and generate the updated casting trajectory; the process optimization training model is also used to calculate the timing adjustment parameters of the vacuum gradient and generate the updated vacuum gradient timing. The updated casting trajectory and the updated vacuum gradient timing are integrated to generate an optimized set of process parameters.

[0030] The working principle and effects of the above technical solution are as follows: Extracting full-dimensional operational data from the digital twin model to generate a basic dataset for algorithm training improves the quality of data sources for machine learning, making subsequent training more closely aligned with actual casting processes and reducing training bias caused by invalid data. Cleaning and extracting features from the basic dataset to generate training samples enhances the targeting of algorithm training, reduces model training redundancy, and avoids irrelevant features interfering with the accuracy of process optimization. Inputting the samples into the algorithm for multi-round iterative training to generate a process optimization training model allows the model to more accurately adapt to the adjustment requirements of the casting process and improves the rationality of process parameter calculations. Based on the optimization model calculations and generating updated casting trajectories and vacuum gradient timing sequences, the accuracy of casting trajectories and vacuum control is improved, making process parameters more suitable for the actual needs of winding casting. Integrating the two types of updated parameters to generate an optimized process parameter set enables the coordinated optimization of casting trajectories and vacuum gradients, making subsequent casting operations more scientific, significantly improving the molding quality of epoxy resin casting, reducing product defects caused by improper processes, and enhancing the stability and reliability of the current transformer insulation structure.

[0031] In one embodiment of the present invention, step S5 includes: S51. Retrieve the residual stress distribution map of the casting body output by the digital twin model, and locate the coordinates and range of the high residual stress area; S52. Start the laser shock strengthening equipment to perform laser shock strengthening treatment on the high residual stress area to generate a stress-uniform insulation structure. S53. Perform full-area airtightness testing on the stress-uniformed insulation structure, identify sealing defects and generate airtightness test results; conduct partial discharge performance verification, test the electrical performance of the insulation structure and generate discharge verification results. S54. Integrating the airtightness test results and discharge verification results, and completing the performance verification, a fully enclosed epoxy resin cast current transformer with oil-free, gas-free, flame-retardant, and explosion-proof characteristics is formed.

[0032] The working principle and effects of the above technical solution are as follows: Retrieving the residual stress distribution map from the digital twin model and locating high-stress areas improves the accuracy of stress treatment, making laser shock strengthening more targeted and reducing resource waste caused by indiscriminate treatment. Activating the laser shock strengthening equipment to treat high-stress areas effectively homogenizes the internal stress of the insulation structure, enhances the mechanical strength of the transformer insulation structure, and reduces cracking and deformation problems caused by stress concentration. Performing full-area airtightness testing and partial discharge verification on the insulation structure comprehensively identifies product sealing and electrical performance defects, preventing sealing failures and excessive partial discharge after the finished product is put into use. Integrating the test results to complete performance verification ensures that all indicators of the finished product meet standards, enabling the transformer to achieve stable characteristics of being oil-free, gas-free, flame-retardant, and explosion-proof. This not only improves the product's operational reliability and service life but also ensures that the product fully meets the environmental and safety requirements of high-voltage power grids, significantly reducing the risk of equipment failure during power grid operation.

[0033] In one embodiment of the present invention, a fully enclosed epoxy resin cast current transformer is provided, the current transformer being used to perform the casting method as described above, the current transformer comprising: Component transfer module: The primary winding and secondary winding are assembled in a preset layout inside the detachable housing to generate the winding assembly to be poured; the winding assembly to be poured is transferred to the fully enclosed pouring station by the transport component, and the clamping component is activated simultaneously to fix the assembly without damage to form a stable pouring cavity; Trajectory planning module: Based on the three-dimensional topography data of the winding assembly, the annular opening and closing casting component is driven to implement dynamic trajectory planning, so that the casting port can perform adaptive path tracking along the complex contour; through multi-level vacuum gradient control technology, low vacuum is used to promote flow in the resin filling stage, and high vacuum is switched to enhance degassing in the curing stage, and compensation resin is injected simultaneously to offset shrinkage stress. Temperature control module: During the resin filling process, the viscosity, temperature and pressure coupling field are monitored in real time through a distributed optical fiber sensor network. When a local gas entrapment tendency is detected, the ultrasonic vibration module is automatically triggered to perform in-situ defoaming. During the curing stage, the infrared thermal imaging system is activated to scan the thermal stress distribution at the interface and drive the semiconductor cooling unit to perform zoned temperature control to eliminate microcracks at the epoxy and metal interfaces. Continuous optimization module: Employs microwave penetration online detection technology to perform 100% real-time scanning of resin density during the curing process. When an abnormal density area is detected, the local micro-injection device is immediately activated to perform precise glue replenishment. Simultaneously, the entire process parameters are recorded and a digital twin model is generated. Machine learning algorithms are used to continuously optimize the pouring trajectory and vacuum timing. Strengthening module: Based on the residual stress distribution map output by the digital twin model, the finished product is subjected to laser shock strengthening treatment to generate a stress-uniform insulation structure; after the final product is tested for air tightness and verified for partial discharge, it forms a fully enclosed epoxy resin cast current transformer with oil-free, gas-free, flame-retardant and explosion-proof characteristics.

[0034] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A casting method for a fully enclosed epoxy resin cast current transformer, characterized in that, The method includes: S1. Assemble the primary winding and secondary winding in a preset layout inside the detachable housing to generate the winding assembly to be poured; transport the winding assembly to be poured to the fully enclosed pouring station through the transport component, and simultaneously start the clamping component to fix the assembly without damage to form a stable pouring cavity. S2. Based on the three-dimensional topography data of the winding assembly, the annular opening and closing casting component is driven to implement dynamic trajectory planning, so that the casting port can implement adaptive path tracking along the complex contour. Through multi-level vacuum gradient control technology, low vacuum is used to promote flow in the resin filling stage, and high vacuum is switched to enhance degassing in the curing stage, while compensating resin is injected simultaneously to offset shrinkage stress. S3. During the resin filling process, the viscosity, temperature and pressure coupling field are monitored in real time through a distributed optical fiber sensor network. When a local gas encapsulation tendency is detected, the ultrasonic vibration module is automatically triggered to perform in-situ defoaming. During the curing stage, the infrared thermal imaging system is activated to scan the interface thermal stress distribution and drive the semiconductor cooling unit to perform zoned temperature control. S4. Microwave penetration online detection technology is used to scan the resin density in real time during the curing process. When an abnormal density area is detected, the local micro-injection device is immediately activated to perform precise glue replenishment. The process parameters of the entire process are recorded simultaneously and a digital twin model is generated. The pouring trajectory and vacuum timing are continuously optimized through machine learning algorithms. S5. Based on the residual stress distribution map output by the digital twin model, laser shock strengthening treatment is applied to the finished product to generate a stress-uniform insulation structure. The S2 includes: S21. Scan the three-dimensional morphology of the winding assembly inside the stable casting cavity, collect contour coordinates and structural gap data, and generate three-dimensional morphology data of the winding. S22. The control module that transmits the three-dimensional topography data of the winding to the annular opening and closing casting component drives the component to perform dynamic trajectory planning and generate an adaptive casting path. S23. The annular opening and closing casting component moves along the adaptive casting path to achieve adaptive path tracking of the casting port to the complex contour of the winding assembly. S24. Activate multi-stage vacuum gradient control technology to adjust the vacuum system to a low vacuum range during the resin filling stage to promote the flow of epoxy resin melt within the cavity. S25. After the resin filling is completed, switch to the curing stage, adjust the vacuum system to the high vacuum range to enhance the degassing inside the resin, and simultaneously inject compensating resin to offset the shrinkage stress during the curing process.

2. The casting method for the fully enclosed epoxy resin cast current transformer according to claim 1, characterized in that, S1 includes: S11. Organize the assembly reference of the primary winding and the secondary winding, and nest them in the inner cavity positioning area of ​​the detachable shell according to the preset layout to generate the winding assembly to be cast. S12. Adjust the operating parameters of the carrier component and smoothly transfer the winding assembly to be poured to the designated reference position of the fully enclosed pouring station. S13. Sensing the positioning status of the winding assembly to be poured, simultaneously activating the multi-point clamping components to apply a balanced clamping force to the non-working surface of the assembly; S14. The outer contour of the adaptable winding assembly is clamped and fixed to form a sealed and gapless stable casting cavity; the sealing performance and positioning accuracy of the stable casting cavity are tested, and pre-casting station test data is generated.

3. The casting method for the fully enclosed epoxy resin cast current transformer according to claim 1, characterized in that, The S3 includes: S31. During the resin filling process, a distributed fiber optic sensor network is activated to monitor the viscosity, temperature and pressure of the epoxy resin melt in the cavity in real time, and generate coupled field monitoring data. S32. Continuously analyze the coupled field monitoring data, capture the local gas entrainment tendency characteristics during the melt flow process, and generate gas entrainment monitoring signals; S33. Upon receiving the air-encapsulation monitoring signal, the ultrasonic vibration module is automatically triggered to perform in-situ high-frequency defoaming treatment on the air-encapsulation area. S34. After entering the curing stage, the infrared thermal imaging system is activated to perform a full-area thermal stress scan on the interface between epoxy and metal, generating interface thermal stress distribution data. S35. Based on the interface thermal stress distribution data, drive the semiconductor cooling unit to implement zoned temperature control in high-stress areas and eliminate the hidden danger of interface microcracks.

4. The casting method for the fully enclosed epoxy resin cast current transformer according to claim 3, characterized in that, The S35 includes: S351. Analyze the interface thermal stress distribution data, extract the location and thermal stress value of high stress areas, and generate basic data for zoned temperature control. S352. Perform gradient division on the basic data of zone temperature control to generate multiple temperature control thresholds; the semiconductor refrigeration unit receives the multiple temperature control thresholds, allocates the working power of each refrigeration module, and generates zone power control instructions. S353. Each cooling module executes a zone power control command to implement differentiated temperature control in high-stress areas and generate zone temperature control effect data. S354. Dynamically fine-tune the cooling power based on regional temperature control effect data, continuously optimize the temperature field distribution, and eliminate the hidden danger of interface micro-cracks.

5. The casting method for the fully enclosed epoxy resin cast current transformer according to claim 4, characterized in that, S352 includes: Extract the thermal stress value range from the basic data of zoned temperature control to generate the basis for dividing the temperature control gradient; divide the zone into multiple levels according to the thermal stress value, calibrate the temperature control critical value of each zone, and generate the initial temperature control threshold. By combining the thermal expansion properties of epoxy and metal, the initial temperature control threshold is modified to generate multiple temperature control thresholds. The semiconductor cooling unit receives multiple temperature control thresholds, matches the temperature control range corresponding to each cooling module, and generates a module power allocation coefficient. The operating power of each refrigeration module is set according to the module power allocation coefficient, and a zone power control command is generated.

6. The casting method for the fully enclosed epoxy resin cast current transformer according to claim 1, characterized in that, The S4 includes: S41. Start the microwave penetration online detection system to perform a 100% real-time full-area scan of the resin density of the casting during the curing process and generate resin density distribution data. S42. Analyze the resin density distribution data, identify the density abnormal area in the casting body, and generate a glue replenishment trigger signal; upon receiving the glue replenishment trigger signal, immediately start the local micro-injection device to perform precise quantitative glue replenishment to the density abnormal area. S43. Synchronously collect process parameters of the entire casting process, integrate and generate a digital twin model of the casting process, and map the solidification state and structural characteristics of the casting body; S44. Input the running data of the digital twin model into the machine learning algorithm, iteratively train and update the casting trajectory and vacuum gradient timing to generate an optimized set of process parameters.

7. The casting method for the fully enclosed epoxy resin cast current transformer according to claim 6, characterized in that, S44 includes: Extract full-dimensional operational data from the digital twin model to generate a basic dataset for algorithm training; perform data cleaning and feature extraction on the basic dataset for algorithm training to generate machine learning training samples; The machine learning training samples are input into the machine learning algorithm to carry out multiple rounds of iterative training and generate a process optimization training model. The process optimization training model is used to calculate the correction parameters of the casting trajectory and generate the updated casting trajectory; the process optimization training model is also used to calculate the timing adjustment parameters of the vacuum gradient and generate the updated vacuum gradient timing. The updated casting trajectory and the updated vacuum gradient timing are integrated to generate an optimized set of process parameters.

8. The casting method for the fully enclosed epoxy resin cast current transformer according to claim 1, characterized in that, The S5 includes: S51. Retrieve the residual stress distribution map of the casting body output by the digital twin model, and locate the coordinates and range of the high residual stress area; S52. Start the laser shock strengthening equipment to perform laser shock strengthening treatment on the high residual stress area to generate a stress-uniform insulation structure. S53. Perform full-area airtightness testing on the stress-uniformed insulation structure, identify sealing defects and generate airtightness test results; conduct partial discharge performance verification, test the electrical performance of the insulation structure and generate discharge verification results. S54. Integrating the airtightness test results and discharge verification results, and completing the performance verification, a fully enclosed epoxy resin cast current transformer with oil-free, gas-free, flame-retardant, and explosion-proof characteristics is formed.

9. An apparatus for manufacturing a fully enclosed epoxy resin cast current transformer, the apparatus being used to perform the casting method as described in claim 1, characterized in that, The device includes: Component transfer module: The primary winding and secondary winding are assembled in a preset layout inside the detachable housing to generate the winding assembly to be poured; the winding assembly to be poured is transferred to the fully enclosed pouring station by the transport component, and the clamping component is activated simultaneously to fix the assembly without damage to form a stable pouring cavity; Trajectory planning module: Based on the three-dimensional topography data of the winding assembly, the annular opening and closing casting component is driven to implement dynamic trajectory planning, so that the casting port can perform adaptive path tracking along the complex contour; through multi-level vacuum gradient control technology, low vacuum is used to promote flow in the resin filling stage, and high vacuum is switched to enhance degassing in the curing stage, and compensation resin is injected simultaneously to offset shrinkage stress. Temperature control module: During the resin filling process, the viscosity, temperature and pressure coupling field are monitored in real time through a distributed optical fiber sensor network. When a local gas encapsulation tendency is detected, the ultrasonic vibration module is automatically triggered to perform in-situ defoaming. During the curing stage, the infrared thermal imaging system is activated to scan the interface thermal stress distribution and drive the semiconductor cooling unit to perform zoned temperature control. Continuous optimization module: Employs microwave penetration online detection technology to perform 100% real-time scanning of resin density during the curing process. When an abnormal density area is detected, the local micro-injection device is immediately activated to perform precise glue replenishment. Simultaneously, the entire process parameters are recorded and a digital twin model is generated. Machine learning algorithms are used to continuously optimize the pouring trajectory and vacuum timing. Strengthening module: Based on the residual stress distribution map output by the digital twin model, the finished product is subjected to laser shock strengthening treatment to generate a stress-uniform insulation structure.

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