Boosting transformer insulation redundancy design method and device, computer equipment, readable storage medium and program product

Abstract

The application relates to a step-up transformer insulation redundancy design method and device, computer equipment, a computer readable storage medium and a computer program product, and belongs to the technical field of transformer design, and the design accuracy of a step-up transformer in a harsh service environment is improved. The method comprises the following steps: obtaining working condition boundary data of a step-up transformer to be designed; according to the insulation structure characteristics of the step-up transformer, the step-up transformer is divided into multiple insulation checking areas; under the condition that multiple preset working conditions corresponding to the working condition boundary data are respectively applied to each insulation checking area, the electric field intensity is obtained; based on the electric field intensity, the safety checking of each insulation checking area is carried out; in the case that the safety checking fails, the adjustment mode of the insulation structure of the insulation checking area is obtained, and after the adjustment, the step of obtaining the electric field intensity of each insulation checking area under multiple preset working conditions is executed again until the safety checking of each insulation checking area is passed.

Description

Technical Field

[0001] This application relates to the field of transformer design technology, and in particular to a method, apparatus, computer equipment, computer-readable storage medium, and computer program product for designing insulation redundancy for step-up transformers. Background Technology

[0002] With the development of nuclear fusion technology, step-up transformers in nuclear fusion accelerator power systems face extremely complex and harsh electromagnetic environments in actual operation. These devices not only need to withstand conventional AC voltage but also often need to withstand multiple complex physical stresses over long periods. In traditional technologies, transformer insulation design typically relies on past engineering experience or focuses only on static, single-type withstand voltage checks. However, this traditional static evaluation method cannot fully reflect the true insulation stress distribution of the equipment under multiple superimposed extreme operating conditions.

[0003] Therefore, traditional technologies suffer from insufficient local insulation margins or excessive redundancy in the overall structure in pursuit of safety. Consequently, accurately assessing and ensuring the insulation reliability of step-up transformers under complex service conditions has become a pressing technical problem to be solved in this field. Summary of the Invention

[0004] Therefore, it is necessary to provide a method, apparatus, computer equipment, computer-readable storage medium, and computer program product for designing insulation redundancy of step-up transformers to address the aforementioned technical problems.

[0005] Firstly, this application provides a method for designing insulation redundancy in a step-up transformer, including:

[0006] Obtain the operating boundary data of the step-up transformer to be designed;

[0007] Based on the insulation structure characteristics of the step-up transformer, the step-up transformer is divided into multiple insulation verification areas;

[0008] By applying multiple preset working conditions corresponding to the working condition boundary data to each of the insulation verification regions, the electric field strength of each of the insulation verification regions under the multiple preset working conditions is obtained.

[0009] Based on the electric field strength of each insulation verification region, a safety verification is performed on each insulation verification region.

[0010] If the safety check of the insulation check area fails, obtain the adjustment method for the insulation structure of the insulation check area, and after adjusting the insulation structure according to the adjustment method, return to the step of obtaining the electric field strength of each insulation check area under the various preset working conditions, until the safety check of each insulation check area passes.

[0011] In one embodiment, the safety verification of each insulation verification region based on the electric field strength of each insulation verification region includes:

[0012] Obtain the withstand field strength of each insulation verification region;

[0013] Based on the withstand field strength and the corresponding electric field strength of each insulation verification region, the insulation redundancy coefficient of each insulation verification region is determined.

[0014] If the insulation redundancy coefficient is less than the insulation redundancy threshold corresponding to the insulation verification area, the safety verification of the corresponding insulation verification area is determined to have failed.

[0015] In one embodiment, the step-up transformer is divided into multiple insulation verification regions based on its insulation structure characteristics, including:

[0016] The two-dimensional and three-dimensional feature structures of the insulation structure of the step-up transformer are obtained; the two-dimensional feature structure includes the oil-paper composite insulation structure, winding arrangement and grounding structure, and the three-dimensional feature structure includes the lead wire outlet method and oil-SF6 bushing structure.

[0017] Based on the two-dimensional characteristic structure of the oil-paper composite insulation structure, the winding arrangement, and the grounding structure, the winding insulation area in the step-up transformer is determined.

[0018] Based on the lead-out method of the three-dimensional feature structure and the oil-SF6 bushing structure, the lead-out area, bushing barrier area and oil-SF6 transition interface area in the step-up transformer are determined.

[0019] The insulation verification area is determined based on the winding insulation area, the lead outlet area, the bushing barrier area, and the oil-SF6 transition interface area.

[0020] In one embodiment, the insulation redundancy threshold includes a first insulation redundancy threshold and a second insulation redundancy threshold;

[0021] The insulation redundancy threshold corresponding to each of the insulation verification areas is determined through the following steps:

[0022] When the insulation verification area includes at least one of the lead outlet area, the bushing barrier area, or the oil-SF6 transition interface area, the corresponding first insulation redundancy threshold is determined based on the three-dimensional feature attributes of the insulation verification area obtained in advance.

[0023] When the insulation verification area includes the winding insulation area, a corresponding second insulation redundancy threshold is determined based on the pre-acquired two-dimensional feature attributes of the insulation verification area; wherein, the first insulation redundancy threshold is higher than the second insulation redundancy threshold.

[0024] In one embodiment, the preset operating conditions include DC withstand voltage condition, long pulse operation condition, and AC withstand voltage condition;

[0025] The step of obtaining the electric field strength of each insulation verification region under the various preset operating conditions corresponding to the operating condition boundary data when applying multiple preset operating conditions to each of the insulation verification regions includes:

[0026] Obtain the dielectric constant model and conductivity model of the insulating material in each of the insulation verification regions;

[0027] Under the preset operating conditions of DC withstand voltage condition or long pulse operation condition, the oil temperature data and winding temperature data of the step-up transformer after operation are obtained;

[0028] Based on the oil temperature data and the winding temperature data, determine the corresponding temperature correction parameters;

[0029] The conductivity model is updated based on the temperature correction parameters, and the corresponding electric field strength is obtained based on the updated conductivity model.

[0030] When the preset operating condition is AC withstand voltage condition, the corresponding electric field strength is obtained based on the dielectric constant model.

[0031] In one embodiment, obtaining the adjustment method for the insulation structure of the insulation verification area includes:

[0032] When the insulation verification area is an oil-SF6 transition interface area, the adjustment method is determined to be at least one of the following processes: adjusting the position of the shielding electrode of the oil-SF6 bushing associated with the oil-SF6 transition interface area, modifying the size of the equalizing ring, changing the bushing barrier length, adjusting the radius of the lead end fillet, and changing the lead bending radius.

[0033] Secondly, this application also provides an insulation redundancy design device for a step-up transformer, comprising:

[0034] The operating condition data acquisition module is used to acquire the operating condition boundary data of the step-up transformer to be designed.

[0035] The verification area determination module is used to divide the step-up transformer into multiple insulation verification areas based on the insulation structure characteristics of the step-up transformer;

[0036] The electric field strength calculation module is used to obtain the electric field strength of each insulation verification area under the various preset working conditions corresponding to the working condition boundary data when applying multiple preset working conditions to each of the insulation verification areas respectively.

[0037] An insulation safety verification module is used to perform safety verification on each insulation verification area based on the electric field strength of each insulation verification area;

[0038] An insulation structure adjustment module is used to obtain an adjustment method for the insulation structure of the insulation verification area when the safety verification of the insulation verification area fails, and after adjusting the insulation structure according to the adjustment method, return to the step of obtaining the electric field strength of each insulation verification area under the various preset working conditions until the safety verification of each insulation verification area passes.

[0039] Thirdly, this application also provides a computer device, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to perform the following steps:

[0040] Obtain the operating boundary data of the step-up transformer to be designed;

[0041] Based on the insulation structure characteristics of the step-up transformer, the step-up transformer is divided into multiple insulation verification areas;

[0042] By applying multiple preset working conditions corresponding to the working condition boundary data to each of the insulation verification regions, the electric field strength of each of the insulation verification regions under the multiple preset working conditions is obtained.

[0043] Based on the electric field strength of each insulation verification region, a safety verification is performed on each insulation verification region.

[0044] If the safety check of the insulation check area fails, obtain the adjustment method for the insulation structure of the insulation check area, and after adjusting the insulation structure according to the adjustment method, return to the step of obtaining the electric field strength of each insulation check area under the various preset working conditions, until the safety check of each insulation check area passes.

[0045] Fourthly, this application also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, performs the following steps:

[0046] Obtain the operating boundary data of the step-up transformer to be designed;

[0047] Based on the insulation structure characteristics of the step-up transformer, the step-up transformer is divided into multiple insulation verification areas;

[0048] By applying multiple preset working conditions corresponding to the working condition boundary data to each of the insulation verification regions, the electric field strength of each of the insulation verification regions under the multiple preset working conditions is obtained.

[0049] Based on the electric field strength of each insulation verification region, a safety verification is performed on each insulation verification region.

[0050] If the safety check of the insulation check area fails, obtain the adjustment method for the insulation structure of the insulation check area, and after adjusting the insulation structure according to the adjustment method, return to the step of obtaining the electric field strength of each insulation check area under the various preset working conditions, until the safety check of each insulation check area passes.

[0051] Fifthly, this application also provides a computer program product, including a computer program that, when executed by a processor, performs the following steps:

[0052] Obtain the operating boundary data of the step-up transformer to be designed;

[0053] Based on the insulation structure characteristics of the step-up transformer, the step-up transformer is divided into multiple insulation verification areas;

[0054] By applying multiple preset working conditions corresponding to the working condition boundary data to each of the insulation verification regions, the electric field strength of each of the insulation verification regions under the multiple preset working conditions is obtained.

[0055] Based on the electric field strength of each insulation verification region, a safety verification is performed on each insulation verification region.

[0056] If the safety check of the insulation check area fails, obtain the adjustment method for the insulation structure of the insulation check area, and after adjusting the insulation structure according to the adjustment method, return to the step of obtaining the electric field strength of each insulation check area under the various preset working conditions, until the safety check of each insulation check area passes.

[0057] The aforementioned method, apparatus, computer equipment, computer-readable storage medium, and computer program product for designing insulation redundancy in step-up transformers acquire the operating condition boundary data of the step-up transformer to be designed; based on the insulation structure characteristics of the step-up transformer, divide the step-up transformer into multiple insulation verification regions; apply various preset operating conditions corresponding to the operating condition boundary data to each insulation verification region, and acquire the electric field strength of each insulation verification region under various preset operating conditions; perform safety verification on each insulation verification region based on the electric field strength of each insulation verification region; if the safety verification of an insulation verification region fails, acquire the adjustment method for the insulation structure of the insulation verification region, and after adjusting the insulation structure according to the adjustment method, return to the step of acquiring the electric field strength of each insulation verification region under various preset operating conditions, until the safety verification of each insulation verification region passes. In this application, by finely dividing the physical structure into multiple verification regions and applying multiple real operating condition boundary data to each region, the limitations of traditional single-condition static evaluation are broken, and the local electric field extrema of the step-up transformer under complex stress are accurately quantified. At the same time, by introducing a mechanism for targeted adjustment and cyclic re-verification of the insulation structure of the verification regions that fail to pass the verification, an objective data-driven feedback closed loop is constructed. This eliminates the local insulation weaknesses of the equipment while avoiding blind and excessive redundancy in the overall structure, and improves the design accuracy of the step-up transformer in harsh service environments. Attached Figure Description

[0058] To more clearly illustrate the technical solutions in the embodiments of this application or related technologies, the drawings used in the description of the embodiments of this application or related technologies will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0059] Figure 1 This is a system architecture diagram of a multi-stage step-up transformer system in one embodiment;

[0060] Figure 2 This is a schematic diagram of the insulation structure of a step-up transformer in one embodiment;

[0061] Figure 3 This is a flowchart illustrating the insulation redundancy design method for a step-up transformer in one embodiment;

[0062] Figure 4a This is a schematic diagram of the insulation verification model of the step-up transformer in different regions in one embodiment;

[0063] Figure 4b This is a schematic diagram of the insulation verification model of the step-up transformer in different regions, as shown in another embodiment.

[0064] Figure 4c This is a schematic diagram of the insulation verification model of the step-up transformer in another embodiment;

[0065] Figure 5 This is a schematic diagram showing the optimization of the electric field at the oil-SF6 bushing transition interface in one embodiment;

[0066] Figure 6 This is a flowchart illustrating the insulation redundancy design method for a step-up transformer in another embodiment;

[0067] Figure 7 This is a structural block diagram of a step-up transformer insulation redundancy design device in one embodiment;

[0068] Figure 8 This is an internal structural diagram of a computer device in one embodiment. Detailed Implementation

[0069] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0070] It should be noted that the terms "first," "second," etc., used in this application can be used to describe various objects, but these objects are not limited by these terms. These terms are only used to distinguish the first object from the second object. The terms "comprising" and "having," and any variations thereof, used in this application, are intended to cover non-exclusive inclusion. The term "multiple" used in this application refers to two or more. The term "and / or" used in this application refers to one of the embodiments, or any combination of multiple embodiments.

[0071] The insulation redundancy design method for step-up transformers provided in this application can be applied to the insulation structure design, verification, and optimization of multi-stage high-voltage DC power systems (such as nuclear fusion acceleration power systems or similar megavolt-level high-voltage DC generation systems). Figure 1The system architecture shown, in this application environment, typically consists of single or multiple cascaded DC generating units. Each core unit includes a power inverter, an isolation step-up transformer, and a high-voltage rectifier. The primary side of the step-up transformer receives low-frequency or high-frequency AC power from the inverter, while the secondary side outputs high-voltage AC power to the rectifier. Due to the multi-stage series connection, the secondary windings and overall output structure of the step-up transformer operate at extremely high DC potentials to ground. In a specific embodiment, the nuclear fusion accelerator power supply includes five-stage step-up transformers and five-stage rectifiers. The five step-up transformers correspond to DC potential levels of -200kV, -400kV, -600kV, -800kV, and -1000kV, respectively. Each step-up transformer receives low-voltage AC input on its primary side and outputs high-voltage AC power on its secondary side, which is then connected to an SF6 gas-insulated rectifier via an oil-SF6 bushing.

[0072] Further integration such as Figure 2 The step-up transformer structure shown typically employs an oil-immersed composite insulation architecture in this application environment. Its internal physical structure includes components such as the core, primary winding, secondary winding, interlayer grounding shield, insulating oil channels, cardboard barriers, and leads. Furthermore, due to the need to connect to the downstream high-voltage rectifier, the transformer's high-voltage output terminals usually extend out of the oil tank and transition to a gas-insulated space via an oil-gas (e.g., oil-SF6) composite insulating bushing. The design method provided in this application relies on the aforementioned transformer physical architecture, which possesses extremely high DC potential to ground, long-pulse AC / DC superimposed stress, and a complex oil-gas interface transition structure. By extracting its operating condition boundary characteristics, it achieves regionalized precise verification and closed-loop iterative optimization of its complex internal insulation structure.

[0073] In one exemplary embodiment, such as Figure 3 As shown, a method for designing insulation redundancy in a step-up transformer is provided, which is then applied to... Figure 1 The following explanation is based on a multi-stage high-voltage DC power supply system, including the following steps S301 to S305:

[0074] Step S301: Obtain the operating boundary data of the step-up transformer to be designed.

[0075] Among them, the step-up transformer to be designed is usually a core isolated power supply device that undertakes the task of converting low-voltage AC to high-voltage AC in a multi-stage high-voltage DC generator and bears extremely high DC potential to ground. For example, it can be a special step-up transformer in a nuclear fusion acceleration power supply system that corresponds to different DC potential levels such as -200kV to -1000kV.

[0076] Operating condition boundary data is used to characterize the set of electrical, thermal, and environmental constraints that the step-up transformer endures under various harsh conditions, such as actual grid operation and various withstand voltage tests. Specifically, this may include, but is not limited to, primary AC voltage, secondary AC voltage, secondary DC potential to ground, long-pulse operating time, cooling method, installation environment, oil-SF6 outlet interface type, and various operating and testing parameters such as AC withstand voltage, DC withstand voltage, and impulse withstand voltage. In a specific embodiment, the rated capacity, primary voltage, secondary voltage, rated frequency, cooling method, secondary DC potential to ground, DC withstand voltage rating, and partial discharge test requirements of the step-up transformer are obtained.

[0077] Specifically, when carrying out the redundant design of the insulation structure of the step-up transformer, we collect various input and output electrical parameters, physical environment parameters and structural interface constraints of the step-up transformer under rated long-term operation and various extreme endurance test conditions, so as to provide an accurate data foundation for building a realistic multi-condition electric field calculation model.

[0078] For example, when acquiring parameters for a step-up transformer at the highest potential level, as shown in Table 1, the acquired operating condition boundary data may include primary side input voltage of AC 4.2kV, secondary side output voltage of AC 141.65kV, secondary winding DC potential to ground as high as -1000kV, and extreme test parameter boundaries such as DC withstand voltage of -1200kV for 1 hour and DC withstand voltage of -1500kV for 5 minutes. It may also include duration parameters under long pulse operation and cooling method characteristics such as oil immersion natural cooling.

[0079] Table 1. DC withstand voltage parameters of step-up transformers at various voltage levels

[0080]

[0081] Step S302: Based on the insulation structure characteristics of the step-up transformer, the step-up transformer is divided into multiple insulation verification areas.

[0082] The insulation structure characteristics of a step-up transformer are typically manifested in the spatial arrangement of the conductive components and insulating media within the equipment, as well as the distribution of interfaces between different media. These characteristics can be obtained based on the engineering design drawings of the transformer or the three-dimensional spatial model of its internal components. They are mainly used to bear and isolate the superimposed AC and DC electric fields under the operating conditions of the equipment. For example, they can be specifically manifested as the concentric arrangement of the core and windings, the layering characteristics of the oil-paper composite insulation barrier, and the transition characteristics of the oil-gas (such as oil-SF6) composite bushing at the output end.

[0083] The insulation verification region can be a discretized analysis block abstracted from the spatial locations within the aforementioned insulation structure that exhibit different insulation failure risks due to differences in electric field distribution and abrupt changes in material properties. It can be spatially segmented and defined based on the objective physical morphology of local electric field distortion or multi-medium composite interfaces within the equipment. It is primarily used in the simulation modeling stage to specifically extract local electric field strength and assess regional redundancy. Specifically, after obtaining the transformer's operating condition constraints, based on the physical structure of the step-up transformer corresponding to the operating condition boundary data, and by acquiring the spatial relative positions of internal components and the distribution of insulation medium interfaces, spatial locations subjected to different types of electric field stress or with risks of surface discharge or breakdown are identified. This decouples the originally large and complex overall insulation architecture into multiple independent subsets of regions (i.e., insulation verification regions) that are easy to constrain in the calculation model, thus establishing a clear model foundation for subsequent localized and differentiated insulation safety analysis.

[0084] For example, for an oil-immersed step-up transformer used for high-voltage output, based on its internal winding arrangement, grounding shield layout, tank casing, and secondary side outgoing line structure, the entire transformer can be decoupled into multiple insulation verification areas with different risk levels. For instance, it can be specifically divided into main insulation areas such as the high-voltage winding-core main insulation area, the high-voltage winding-low-voltage winding main insulation area, the high-voltage winding-tank main insulation area, and the low-voltage winding-tank insulation area. It can also be divided into edge and transition areas with more severe local electric field distortion, such as the winding end insulation area, lead outlet area, bushing barrier area, oil-SF6 transition interface area, and grounding shield edge area.

[0085] Alternatively, when dividing such areas, in addition to relying on the spatial boundaries of physical components, the physical characteristics of the insulating medium in each area (such as pure oil-paper composite areas and oil-gas interface composite areas) can be comprehensively considered to define the blocks, so as to ensure that all potential high-risk insulation weak points inside the transformer are covered.

[0086] Step S303: Under the condition of applying multiple preset working conditions corresponding to the working condition boundary data to each insulation verification area, obtain the electric field strength of each insulation verification area under multiple preset working conditions.

[0087] Among them, the various preset operating conditions can be a series of standardized electromagnetic excitation and thermal loading boundary states faced by the step-up transformer during factory inspection, long-term service, and when dealing with transient impacts. These conditions can be derived from the aforementioned extracted operating parameters and test requirements. They are mainly used to equivalently reproduce various extreme insulation stresses that the equipment may encounter in real scenarios in the simulation modeling environment. For example, these conditions may include, but are not limited to, AC external withstand voltage, AC induced withstand voltage, DC 1h withstand voltage, DC 5min withstand voltage, impulse withstand voltage, and rated long pulse operating conditions.

[0088] Electric field strength can be the spatial distribution of the potential gradient at each spatial node inside the step-up transformer. It can be obtained by physical field numerical calculation based on the applied preset operating condition excitation and the electromagnetic characteristic parameters of the insulating material in the region. It is mainly used as a direct physical characterization to quantitatively describe whether the insulating medium is facing the risk of breakdown or surface discharge in a local area.

[0089] Specifically, after dividing the model space into regions, the electric field intensity of each insulation verification region is obtained under various preset working conditions corresponding to the boundary data. This process mainly involves loading electrical signals and thermal constraints of different dimensions onto the constructed region model boundary, and using a numerical solution engine to extract the extreme values ​​of the potential gradient distribution of each independent segment when facing complex physical field excitation, thereby providing accurate quantitative data input for subsequent dielectric tolerance determination.

[0090] For example, when solving the electric field for different verification regions, targeted operating conditions can be applied based on the actual location of each region in the multi-stage high-voltage generation cascade architecture. For instance, an AC excitation with high frequency and non-sinusoidal characteristics can be applied to the primary input terminal, while an AC superimposed negative polarity constant high-voltage constraint of up to hundreds of kilovolts can be applied to the secondary side. Specifically, AC external withstand voltage, AC induced withstand voltage, DC 1-hour withstand voltage, DC 5-minute withstand voltage, impulse withstand voltage, and rated long pulse operation conditions are applied to each insulation verification region. For example, for the highest potential level step-up transformer, under the DC 1-hour withstand voltage condition, a -1200kV potential is applied to the secondary side; under the DC 5-minute withstand voltage condition, a -1500kV potential is applied to the secondary side; and under the AC withstand voltage and impulse withstand voltage conditions, excitation is applied according to the corresponding test voltage.

[0091] Optionally, to ensure the conservatism and rigor of the extracted field strength data, after applying and calculating multiple preset working conditions to the same insulation verification area, all field strength analysis results generated in the area under each individual working condition can be compared and the highest value can be extracted. This maximum value can be used as the final maximum calculated field strength of the area for subsequent evaluation, so as to eliminate the insulation weakness blind spots that may be missed in the single working condition verification.

[0092] Step S304: Based on the electric field strength of each insulation verification area, perform a safety verification on each insulation verification area.

[0093] Specifically, after obtaining the extreme values ​​of the potential gradient distribution of each insulation verification area under multiple operating conditions, a mapping relationship is established between the electric field calculation results and the inherent withstand voltage properties of each area. The quantitative stress data output by the physical field simulation is transformed into an intuitive safety index characterizing the local insulation reliability, thereby enabling the determination of the rationality of the current insulation design of each independent block inside the transformer.

[0094] For example, when assessing the safety status of complex composite insulation regions (such as oil-SF6 transition interface regions or winding end regions), the most stringent operating condition limit among the breakdown field strength of the oil gap, the surface withstand field strength of the paperboard, and the partial discharge initiation field strength in the region can be extracted as the benchmark withstand capability of the specific insulation verification region. Subsequently, the ratio of the benchmark withstand capability to the electric field strength is calculated to obtain the insulation redundancy coefficient of the region, and the coefficient is compared to see if it meets the preset safety threshold.

[0095] Optionally, when executing specific safety verification logic, differentiated judgment standards can be configured for different types of insulation verification areas. For example, for the oil-gas transition interface area containing a three-dimensional electric field concentration, a higher redundancy judgment threshold can be set compared to the conventional main insulation area, so as to dynamically judge whether the spatial arrangement and material selection of each local area truly meet the long-term safe service standards of high-voltage equipment.

[0096] Step S305: If the safety verification of the insulation verification area fails, obtain the adjustment method for the insulation structure of the insulation verification area, and after adjusting the insulation structure through the adjustment method, return to the step of obtaining the electric field strength of each insulation verification area under various preset working conditions, until the safety verification of each insulation verification area passes.

[0097] The adjustment method can be a specific physical structure optimization or size change strategy adopted for the insulation verification area that failed the safety verification. It can be determined based on the specific three-dimensional or two-dimensional structural characteristics and electric field concentration location of the local area, and is used to improve the local potential distribution and reduce the maximum potential gradient on the dielectric surface. For example, it can be a specific spatial modification method such as increasing the insulating oil gap distance, modifying the size of the equalizing ring, adjusting the position of the shielding electrode, or changing the radius of the rounded corner of the outgoing terminal.

[0098] Specifically, if the safety check of an insulation verification area fails, the system obtains the adjustment method for the insulation structure of that area. After adjusting the insulation structure according to the method, it returns to the step of obtaining the electric field strength of each insulation verification area under various preset operating conditions, until the safety check of each insulation verification area passes. This process mainly establishes a dynamic closed-loop iterative optimization mechanism. Once a local insulation weakness is identified, a targeted structural change is introduced, and a new round of multi-condition physical field recalculation and redundancy reassessment is driven based on the updated model parameters. This simulation and verification are repeated until all segmented local blocks meet the qualification standards.

[0099] For example, if the safety verification of a high-risk oil-SF6 transition interface area fails (e.g., the redundancy coefficient obtained from the assessment is lower than the corresponding high-risk threshold), the corresponding adjustment method can be obtained, such as moving the position of the shielding electrode of the bushing away from the side of high electric field distortion, or increasing the radius of curvature of the equalizing ring to smooth the electric field distribution.

[0100] Optionally, if the conventional winding insulation area fails the safety check, adjustments can be made such as increasing the width of the interlayer oil channels or fine-tuning the position of the grounding shield. After updating the physical dimensions or spatial positions as described above, preset operating conditions such as AC withstand voltage, DC withstand voltage, and long pulse operation are applied to the adjusted structural model again. The electric field intensity distribution is extracted again, and the safety status of the area is recalculated until all insulation check areas within the transformer can stably cover the withstand requirements under various extreme operating conditions.

[0101] In this embodiment, by finely dividing the physical structure into multiple verification regions and applying multiple real operating condition boundary data to each region, the limitations of traditional single-condition static evaluation are broken, and the local electric field extrema of the step-up transformer under complex stress are accurately quantified. At the same time, by introducing a mechanism for targeted adjustment and cyclic re-verification of the insulation structure of the verification regions that fail to pass the verification, an objective data-driven feedback closed loop is constructed. This eliminates local insulation weaknesses of the equipment while avoiding blind and excessive redundancy in the overall structure, and improves the design accuracy of the step-up transformer under harsh service environments.

[0102] In one embodiment, a safety check is performed on each insulation check region based on the electric field strength of each insulation check region, including:

[0103] Obtain the withstand field strength of each insulation verification region; based on the withstand field strength and the corresponding electric field strength of each insulation verification region, determine the insulation redundancy coefficient of each insulation verification region; if the insulation redundancy coefficient is less than the insulation redundancy threshold corresponding to the insulation verification region, determine that the safety verification of the corresponding insulation verification region has failed.

[0104] Among them, the withstand field strength can usually be the limiting potential gradient limit that a specific insulating medium or composite insulating structure can withstand before breakdown, flashover or irreversible partial discharge occurs. It can be obtained based on the physical property test manual of the insulating material or the previous standard breakdown test data. For example, it can be the breakdown field strength of a pure oil gap of a specific width or the surface withstand field strength of the insulating paperboard.

[0105] Insulation redundancy factor is a quantifiable indicator of the safety margin retained under the current insulation design state. It is mainly used to visually reflect the distance of a local insulation structure from the physical failure boundary. Insulation redundancy threshold is a minimum acceptable boundary limit set in advance for different electric field distortion risks and dielectric composite states. It can be customized based on long-term engineering experience or the severity of failure consequences in a specific area. It is mainly used as a hard criterion for determining whether the current safety margin meets the standard.

[0106] Specifically, when performing detailed safety checks on each insulation verification area, the withstand field strength of each insulation verification area is first extracted and obtained based on the dielectric material properties of different areas. In an optional embodiment, if there are multiple withstand field strength criteria for a certain verification insulation area, the smaller withstand field strength is taken as the withstand field strength of that area. For example, for the oil-paper composite main insulation area, the oil gap breakdown field strength, the paperboard surface withstand field strength, and the partial discharge initiation field strength are considered simultaneously, and the minimum value is taken as the withstand field strength to establish the local compressive strength benchmark. Subsequently, a mathematical relationship is established between the compressive strength benchmark and the actual simulated stress. That is, based on the withstand field strength and the corresponding electric field strength of each insulation verification area, the insulation redundancy coefficient of each insulation verification area is determined through specific calculation logic, thereby making the implicit electric field distribution data explicit into an intuitive safety margin value. Finally, the calculated actual margin is compared with the preset safety baseline. If the insulation redundancy coefficient is less than the insulation redundancy threshold corresponding to the insulation verification area, it is determined that the insulation configuration of that area cannot withstand the extreme working conditions, and thus the safety check of the corresponding insulation verification area is determined to be unsuccessful.

[0107] For example, when determining the insulation redundancy coefficient, a ratio calculation method can be used, that is, dividing the withstand field strength of a specific region by the maximum calculated electric field strength extracted from that region under multiple operating conditions, and the resulting ratio is the insulation redundancy coefficient of that region. In a specific embodiment, the insulation redundancy coefficient... Calculate using the following formula:

[0108]

[0109] In the formula, For the first Insulation redundancy coefficient of each insulation check area; For the first The withstand field strength of each insulation verification area under the corresponding working conditions; For the first The maximum calculated field strength obtained in multi-condition electric field calculations for each insulation verification region.

[0110] In this embodiment, the insulation redundancy coefficient is determined by introducing quantitative calculations of the withstand field strength and the actual electric field strength, and the threshold interception comparison is used to adjudicate the failure state. This realizes the transformation of the abstract and variable physical field distribution into a structural safety index that can be intuitively measured in engineering, eliminates the ambiguity caused by relying on subjective experience to judge insulation, and ensures that the insulation margin of each local area inside the transformer can be accurately quantified.

[0111] In one embodiment, based on the insulation structure characteristics of the step-up transformer, the step-up transformer is divided into multiple insulation verification areas, including:

[0112] The insulation structure characteristics of the step-up transformer are obtained in two dimensions and three dimensions. The two-dimensional characteristic structure includes the oil-paper composite insulation structure, winding arrangement, and grounding shield structure. The three-dimensional characteristic structure includes the lead-out method and the oil-SF6 bushing structure. Based on the oil-paper composite insulation structure, winding arrangement, and grounding shield structure of the two-dimensional characteristic structure, the winding insulation area in the step-up transformer is determined. Based on the lead-out method and oil-SF6 bushing structure of the three-dimensional characteristic structure, the lead-out area, bushing barrier area, and oil-SF6 transition interface area in the step-up transformer are determined. Based on the winding insulation area, lead-out area, bushing barrier area, and oil-SF6 transition interface area, the insulation verification area is determined.

[0113] Among them, the two-dimensional characteristic structure is usually a physical configuration in which the transformer has high geometric symmetry in the axial or radial direction and the electric field distribution mainly exhibits planar or rotational symmetry characteristics. It is mainly used to support large-area conventional main insulation isolation, such as concentric cylindrical oil-paper composite insulation structure, regularly distributed winding arrangement, and stacked grounding shield structure, etc.

[0114] The three-dimensional characteristic structure is a complex physical component with irregular internal geometry, abrupt changes in spatial medium, and significant three-dimensional distortion effect of electric field distribution. It is mainly used to cope with the spatial intersection of high and low voltage leads and the transition between different insulating medium environments (such as oil and gas). For example, it can be a lead-out method with complex spatial bending radius, as well as an oil-SF6 bushing structure involving multiple shielding components and asymmetric equalizing rings.

[0115] Specifically, when performing spatial block decomposition based on the overall insulation structure characteristics of the transformer, the complex physical space inside the transformer is first subjected to dimensionality reduction and classification extraction to obtain the two-dimensional and three-dimensional feature structures of the transformer's insulation structure. Subsequently, based on spatial symmetry and the distribution range of the main insulation, the winding insulation region in the step-up transformer is determined according to the oil-paper composite insulation structure, winding arrangement, and grounding shield structure of the two-dimensional feature structure. In some scenarios, this winding insulation region may include the high-voltage winding-low-voltage winding main insulation region, the high-voltage winding-tank main insulation region, and the low-voltage winding-tank insulation region. The system identifies the insulation regions, winding end insulation regions, and grounding insulation regions. Simultaneously, for locations prone to severe electric field distortion due to spatial abrupt changes, based on the lead-out method of the three-dimensional characteristic structure and the oil-SF6 bushing structure, the lead-out region, bushing barrier region, and oil-SF6 transition interface region in the step-up transformer are determined. Finally, the basic main insulation blocks obtained from the dimensionality reduction mapping are combined and integrated with the high-risk edge blocks. Based on the winding insulation region, lead-out region, bushing barrier region, and oil-SF6 transition interface region, the insulation verification region is determined. Further statistical analysis of the electric field strength yields the following results: Figure 4a , Figure 4b as well as Figure 4c The simulation structure is shown.

[0116] For example, when extracting two-dimensional feature structures for a specific megavolt-level step-up transformer, the focus can be on extracting the thickness of the internal insulating paperboard, the size of the oil channel gap, and the interlayer arrangement. Based on this, the winding insulation area can be spatially expanded into multiple conventional main insulation blocks, such as the main insulation area between the high-voltage winding and the core, the main insulation area between the high-voltage winding and the low-voltage winding, and the main insulation area between the high-voltage winding and the outer oil tank of the transformer. These subdivided two-dimensional structural blocks can usually meet the engineering evaluation requirements by using a two-dimensional axisymmetric simulation model in the subsequent electric field solution. Optionally, when extracting three-dimensional feature structures, it is necessary to focus on extracting the flange geometry at the bushing tail, the three-dimensional curvature of the equalizing ring, and the actual spatial orientation angle of the lead wire. The areas such as the lead wire outlet, bushing barrier, and oil-SF6 transition interface determined in this way will be given the judgment logic for establishing a full three-dimensional electric field simulation model in the subsequent evaluation due to the obvious edge aggregation effect. Therefore, in some scenarios, step-up transformers can be divided into nine insulation verification areas, from A to I: Area A is the main insulation area between the high-voltage winding and the core; Area B is the main insulation area between the high-voltage winding and the low-voltage winding; Area C is the main insulation area between the high-voltage winding and the oil tank; Area D is the insulation area between the low-voltage winding and the oil tank; Area E is the insulation area at the winding ends; Area F is the lead outlet area; Area G is the bushing barrier area; Area H is the oil-SF6 transition interface area; and Area I is the grounding shield edge area. For Areas A, B, C, D, and E, a two-dimensional axisymmetric model can be used for preliminary calculations. For Areas F, G, and H, since the lead, bushing, equalizing ring, and flange structures have significant three-dimensional characteristics, a three-dimensional electric field model is preferred for detailed local calculations.

[0117] In this embodiment, the above steps are used to divide the complex internal space of the transformer according to the structural symmetry and the degree of failure risk. This achieves the goal of avoiding overly complex modeling of regular areas in subsequent analysis, thus saving computing power, while ensuring that high-risk asymmetric edge areas are subject to three-dimensional fine verification to prevent omissions. This balances the efficiency of insulation assessment with overall accuracy.

[0118] In one embodiment, the insulation redundancy threshold includes a first insulation redundancy threshold and a second insulation redundancy threshold;

[0119] The insulation redundancy threshold corresponding to each insulation check area is determined through the following steps:

[0120] When the insulation verification area includes at least one of the lead outlet area, bushing barrier area, or oil-SF6 transition interface area, a corresponding first insulation redundancy threshold is determined based on the pre-acquired three-dimensional feature attributes of the insulation verification area; when the insulation verification area includes the winding insulation area, a corresponding second insulation redundancy threshold is determined based on the pre-acquired two-dimensional feature attributes of the insulation verification area; wherein, the first insulation redundancy threshold is higher than the second insulation redundancy threshold.

[0121] Among them, the first insulation redundancy threshold and the second insulation redundancy threshold are differentiated safety baseline indicators set for different spatial forms and electric field distortion degrees inside the transformer, which are used to provide customized judgment benchmarks that match the actual failure risk of different types of insulation blocks.

[0122] Three-dimensional characteristic attributes represent the physical properties of a region in space, such as multi-dimensional medium interfaces, sharp edges, or complex asymmetric geometric structures. They are mainly used to characterize the high-risk state in which the region is prone to three-dimensional electric field concentration and partial discharge.

[0123] Two-dimensional features are characterized by a relatively flat and symmetrical geometric shape of the region, and the electric field distribution mainly exhibits a regular planar or axisymmetric state. They are mainly used to characterize the relatively stable and controllable electromagnetic field constraint state of conventional main insulation regions.

[0124] Specifically, when assigning safety judgment criteria to each insulation verification area, the physical morphological characteristics and failure risks of each area are first identified. When the insulation verification area includes at least one of the lead outlet area, bushing barrier area, or oil-SF6 transition interface area, due to the strong three-dimensional electric field distortion in such areas, a corresponding first insulation redundancy threshold is determined based on the pre-acquired three-dimensional characteristic attributes of the insulation verification area. Conversely, when the insulation verification area includes the winding insulation area, due to its relatively flat and regular electric field distribution, a corresponding second insulation redundancy threshold is determined based on the pre-acquired two-dimensional characteristic attributes of the insulation verification area. Simultaneously, to mitigate the higher breakdown risk caused by complex edge effects, the first insulation redundancy threshold is set higher than the second insulation redundancy threshold. For example, after calculating the insulation redundancy coefficient based on the withstand field strength and calculated field strength of each area, differentiated threshold judgment conditions as shown in Table 2 can be matched.

[0125] Table 2 Redundancy threshold settings for different insulation verification areas

[0126]

[0127] Specifically, for the main insulation areas such as high-voltage winding-core, high-voltage winding-low-voltage winding, and high-voltage winding-tank, which have two-dimensional characteristic attributes, their failure risk level is usually assessed as high. In this case, the second insulation redundancy threshold can be set to 1.20. That is, if the redundancy coefficient is not less than 1.20, the main insulation area of ​​the winding is judged to meet the safety requirements. Optionally, for the winding end insulation area and grounding shield edge area between large-area main insulation and extremely complex structure, it is recommended to set the redundancy threshold to not less than 1.25. Furthermore, for areas with obvious three-dimensional characteristic attributes, their failure risk level is usually assessed as very high, and the corresponding first insulation redundancy threshold needs to be adjusted upwards accordingly. For example, for lead outlet areas and bushing barrier areas, if the calculated redundancy coefficient is not less than 1.30, it is determined that the requirements are met; while for the oil-SF6 transition interface area that bears the worst three-dimensional electric field and multi-medium cross-border stress, the corresponding first insulation redundancy threshold can be further increased to 1.35, that is, if the redundancy coefficient is not less than 1.35, then the cross-border interface area is determined to meet the safety requirements.

[0128] In this embodiment, by introducing two-dimensional and three-dimensional feature attributes as evaluation criteria, and accordingly setting the first insulation redundancy threshold of high-risk complex edge areas to a higher level than the second insulation redundancy threshold of conventional main insulation areas, a precise dynamic matching between insulation safety judgment criteria and local physical failure risk is achieved.

[0129] In one embodiment, the preset operating conditions include DC withstand voltage condition, long pulse operation condition, and AC withstand voltage condition;

[0130] By applying various preset operating conditions corresponding to the boundary data to each insulation verification region, the electric field intensity of each insulation verification region under various preset operating conditions is obtained, including:

[0131] Obtain the dielectric constant model and conductivity model of the insulation material in each insulation verification area; under the preset operating conditions of DC withstand voltage condition or long pulse operation condition, obtain the oil temperature data and winding temperature data of the step-up transformer after operation; determine the corresponding temperature correction parameters based on the oil temperature data and winding temperature data; update the conductivity model based on the temperature correction parameters, and obtain the corresponding electric field intensity based on the updated conductivity model; under the preset operating condition of AC withstand voltage condition, obtain the corresponding electric field intensity based on the dielectric constant model.

[0132] Among them, the DC withstand voltage condition and the long pulse operation condition are constrained states in which the step-up transformer is subjected to long-term DC high potential stress or continuous large load output, resulting in significant internal thermal effects; while the AC withstand voltage condition is characterized by the equipment being subjected to transient boundary conditions of short-term or high-frequency alternating electromagnetic excitation.

[0133] Dielectric constant models and conductivity models can be mathematical expressions or sets of basic physical parameters that characterize the polarization and conductivity properties of various insulating media (such as insulating oil, insulating paperboard, pads, etc.) inside a step-up transformer under the action of an electric field. They are mainly used to dominate and analyze the spatial distribution of the potential gradient under alternating electromagnetic fields and constant or long-term DC electric fields, respectively.

[0134] Oil temperature data and winding temperature data represent the temperature field indicators formed on the internal insulating fluid and conductive copper busbars after a period of heat generation and heat dissipation equilibrium under specific load conditions.

[0135] Temperature correction parameters can be adjustment factors used to quantify the nonlinear variation of the electromagnetic properties of insulating materials with temperature, and to dynamically correct the dielectric or impedance characteristics of materials under long-term temperature rise conditions.

[0136] Specifically, when extracting the spatial potential distribution for different test or operating conditions, the dielectric constant model and conductivity model of the insulating material in each insulation verification area are first obtained to provide a material property basis for subsequent field strength calculation. Then, differentiated field strength analysis strategies are adopted according to different excitation types. Under the preset operating conditions of DC withstand voltage or long-pulse operation, considering the thermal accumulation effect accompanying long-term operation, the oil temperature and winding temperature data of the step-up transformer after operation are obtained. Then, based on the oil temperature and winding temperature data, the corresponding temperature correction parameters are determined. The conductivity model is updated based on the temperature correction parameters, and the numerical simulation engine is driven by the updated conductivity model to obtain the corresponding electric field strength. Conversely, under the preset operating condition of AC withstand voltage, since the potential distribution in the alternating field is mainly determined by capacitive impedance, the complex correction of conductivity by temperature rise is skipped, and the corresponding electric field strength is directly obtained based on the dielectric constant model characterizing polarization characteristics.

[0137] For example, for long-pulse high-voltage transformers used in scenarios such as nuclear fusion, when running a constant long pulse for thousands of seconds, the conductivity of the internal insulating oil and oil-impregnated paperboard will change nonlinearly with the local temperature rise. At this time, based on the oil temperature and winding temperature after operation, the volume conductivity parameters of the materials are dynamically updated by temperature correction parameters, and the DC potential distribution at this time is recalculated to extract the verification field strength under thermal steady state.

[0138] For example, for preset operating conditions such as impact withstand voltage or conventional AC test, the material heating is not obvious because the duration is extremely short or the alternating effect is dominant. Therefore, it is only necessary to input the relative permittivity of each insulating component into the region model, and accurately calculate the local AC electric field intensity according to the transient voltage spatial capacitance coupling distribution law.

[0139] In this embodiment, by introducing a differentiated material parameter modeling mechanism for AC / DC multi-condition operation, especially under long pulse and DC withstand voltage conditions, the conductivity model of the insulating medium is dynamically updated based on actual thermodynamic temperature field data. This enables accurate tracking and simulation mapping of the actual insulation stress evolution process of the transformer under multi-physics field (electromagnetic-thermal) coupling, effectively eliminating the serious distortion caused by using a single room temperature parameter or a single alternating capacitor model for long-term DC electric field evaluation.

[0140] In one embodiment, obtaining the adjustment method for the insulation structure of the insulation verification area includes:

[0141] When the insulation verification area is the oil-SF6 transition interface area, the adjustment method shall be determined as at least one of the following: adjusting the position of the shielding electrode of the oil-SF6 bushing associated with the oil-SF6 transition interface area, modifying the size of the equalizing ring, changing the bushing barrier length, adjusting the fillet radius of the lead end, and changing the bending radius of the lead wire.

[0142] Specifically, after identifying the specific blocks with potential insulation failure risks, the adjustment method for the insulation structure of the target insulation verification area is obtained. Specifically, based on the electric field distortion characteristics of the specific area, a corresponding structural improvement strategy is matched and implemented; in the case where the target insulation verification area is an oil-SF6 transition interface area, such as... Figure 5 As shown, considering that the interface area is subjected to the most complex AC and DC superimposed stress and is prone to three-dimensional electric field distortion, the adjustment method is determined to be at least one of the following: adjusting the position of the shielding electrode of the oil-SF6 bushing associated with the oil-SF6 transition interface area, modifying the size of the equalizing ring, changing the bushing barrier length, adjusting the fillet radius of the lead end, and changing the bending radius of the lead wire, thereby reducing the local electric field intensity through the direct intervention of the above-mentioned spatial structure size and three-dimensional curvature.

[0143] For example, in addition to the interventions mentioned above for complex oil-gas transition interface areas, if the assessed target insulation verification area is another conventional or peripheral area, a corresponding adjustment strategy can be optionally matched according to the structural characteristics of that area. For instance, when the insulation redundancy coefficient of the main insulation area of ​​the high-voltage winding-low-voltage winding is lower than the threshold, the main insulation redundancy can be improved by adjusting one or more of the following methods: main oil channel width, number of cardboard shielding layers, grounding shield position, increasing grounding shield length, and increasing winding radial spacing. When the insulation redundancy coefficient of the winding end area is lower than the threshold, the end insulation redundancy can be improved by one or more combinations of the following methods: adjusting end cardboard thickness, optimizing end ring structure, increasing end oil gap distance, adjusting support bar arrangement, pad arrangement, and adding winding end shielding structure. Similarly, for the lead wire outlet area, when it faces a high insulation risk, targeted insulation structure reinforcement can be carried out by auxiliary means such as increasing the lead wire bending radius, increasing lead wire insulation thickness, setting lead wire shielding tubes, adjusting the distance between the lead wire and the grounding component, or optimizing the cardboard structure near the lead wire outlet.

[0144] In this embodiment, when the safety check fails, the target insulation check area is accurately identified, and a series of highly targeted physical structural correction methods are matched according to the specific characteristics of its location (whether it is the complex cross-border oil-SF6 transition interface area, or the conventional winding main insulation, end area, and lead outlet area). These methods include adjusting the curvature of the shielding component, adding cardboard screens, or widening the oil gap space. This transforms the abstract state of insufficient local redundancy into a physical geometric modification action that can be implemented. This effectively weakens the local three-dimensional or planar electric field concentration effect, comprehensively improves the insulation margin of each high-risk part of the step-up transformer, and thus protects the ultra-high DC potential equipment from damage under extreme operating conditions.

[0145] To enable those skilled in the art to better understand the above steps, the following example illustrates the embodiments of this application, but it should be understood that the embodiments of this application are not limited thereto.

[0146] Specifically, such as Figure 6As shown, specifically, at the beginning of the insulation redundancy design, step S1, determining operating and test parameters, is performed first to obtain boundary data of the step-up transformer, including rated capacity, primary voltage, secondary voltage, rated frequency, cooling method, secondary DC potential to ground, DC withstand voltage level, and partial discharge test requirements. For example, for multi-stage series systems, to achieve standardized insulation design, the obtained operating data can cover DC withstand voltage parameters for multiple potential levels. For instance, for the first to fifth stage step-up transformers, their rated DC potentials correspond to -200kV, -400kV, -600kV, -800kV, and the highest -1000kV, respectively; correspondingly, the test standards for each stage also increase in a stepwise manner, with the DC 1-hour withstand voltage for the first to fourth stages set at -240kV, -480kV, -720kV, and -960kV, respectively. Furthermore, taking the fifth-level (highest potential level) step-up transformer as an example, the extreme operating condition boundary data obtained in step S1 can be specifically as follows: the primary side voltage is AC 4.2kV, the secondary side voltage is AC 141.65kV, the secondary winding DC potential to ground is -1000kV, the DC withstand voltage test for 1 hour requires the application of -1200kV, and the DC withstand voltage test for 5 minutes requires the application of an extreme excitation as high as -1500kV.

[0147] Subsequently, step S2, insulation region division, is performed. Based on the complex physical structure of the step-up transformer, its insulation space is exhaustively divided into nine insulation verification regions, from A to I. Differentiated simulation dimensionality reduction strategies are matched according to the electric field distortion characteristics of each region. For example, conventional main insulation and end regions suitable for calculation using a two-dimensional axisymmetric model can be segmented, specifically including the high-voltage winding-core main insulation region in region A, the high-voltage winding-low-voltage winding main insulation region in region B, the high-voltage winding-tank main insulation region in region C, the low-voltage winding-tank insulation region in region D, and the winding end insulation region in region E. At the same time, complex edge and interface regions requiring detailed calculation using a three-dimensional electric field model are segmented, specifically including the lead outlet region in region F, the bushing barrier region in region G, and the oil-SF6 transition interface region in region H. Since the lead bending, equalizing ring, and flange structures in these regions have extremely strong irregular three-dimensional features, it is preferable to construct a full three-dimensional electric field model to capture partial discharge hazards. In addition, for the grounding shield edge region in region I, the corresponding dimensional model can be flexibly selected.

[0148] After completing the region segmentation and modeling strategy mapping, step S3, material parameter modeling, is executed, inputting the physical material parameters of various components such as insulating oil, insulating paperboard, copper windings, and bushing insulation into the calculation model. For example, for AC external or induced operating conditions, the relative permittivity of each insulating component is mainly input; for DC long-term operating conditions, the volume conductivity of each medium is mainly input. Optionally, in temperature rise correction conditions, the conductivity parameters of the materials can be dynamically updated based on the thermal steady-state oil temperature and winding temperature reached after long-term operation, and the deteriorated DC potential distribution can be recalculated. After material modeling is completed, step S4, multi-condition electric field calculation, is executed, applying AC external withstand voltage, AC induced withstand voltage, DC 1-hour withstand voltage, DC 5-minute withstand voltage, impulse withstand voltage, and rated long-pulse operating conditions to each insulation verification region, and extracting the maximum electric field strength under each condition as the final verification field strength.

[0149] After acquiring the potential gradient data for each region, step S5, insulation redundancy coefficient calculation and determination, is performed. Multiple withstand criteria and differentiated safety thresholds are introduced for regional safety verification. For example, if multiple failure possibilities exist in a certain insulation verification area, the smallest value among the oil gap breakdown field strength, the cardboard surface withstand field strength, and the partial discharge initiation field strength is extracted as the benchmark withstand field strength. Subsequently, the ratio of the benchmark withstand field strength to the maximum calculated field strength extracted in step S4 is calculated to determine the insulation redundancy coefficient, and a stepped determination threshold is matched: for main insulation areas such as areas A, B, and C, if the redundancy coefficient is not less than 1.20, the requirement is met; for areas E and I, the determination threshold is set to 1.25; for areas F and G, the determination threshold is increased to 1.30; and for area H, which has an extremely high risk of cross-medium failure, a redundancy coefficient of not less than 1.35 is required for the safety verification to pass.

[0150] If any region fails the aforementioned safety assessment, step S6, structural optimization of the insufficient redundancy region, is executed, entering a closed-loop structural optimization process for the insufficient redundancy region. For example, in addition to conventional main insulation intervention, for the bushing barrier region in area G, measures such as extending the bushing barrier length, adjusting the bushing shield electrode position, or setting an equalizing ring can be taken; for the oil-SF6 transition interface region in area H, the internal shielding structure of the bushing can be further adjusted, the flange radius can be optimized, or the cross-boundary insulation distance between the oil side and the gas side can be increased. After each structural adjustment is performed in step S6, the model will automatically return to step S4 to recalculate the multi-condition electric field and iteratively assess the situation until all blocks meet their respective set thresholds.

[0151] Finally, after the insulation redundancy design in the simulation space has met all standards and been finalized, the structural drawings have been output, and the physical manufacturing has been completed, step S7, experimental verification, is executed to conduct a complete set of physical tests to form the final technical closed loop. For example, the experimental verification includes not only conventional short-circuit impedance and no-load loss measurements, but more importantly, it involves sequentially performing AC external withstand voltage, AC induced withstand voltage, DC 1-hour withstand voltage (e.g., -1200kV), DC 5-minute withstand voltage (e.g., -1500kV), and partial discharge tests. If no breakdown, flashover, or abnormal growth of characteristic gases in the oil occurs during the entire test process, the insulation redundancy design of the step-up transformer is deemed effective. If an anomaly occurs, the source is traced back to the corresponding insulation verification area, and the simulation process is returned for targeted structural optimization.

[0152] This embodiment is applicable to the special operating conditions of nuclear fusion accelerator power supplies. It simultaneously considers low-voltage AC input, high-voltage AC output, high DC potential to ground on the secondary side, multi-stage negative high-voltage series connection, and long-pulse operation conditions, making it suitable for the insulation design of step-up transformers ranging from -200kV to -1000kV; achieving regional insulation redundancy design. The step-up transformer is divided into multiple insulation verification areas, and differentiated redundancy thresholds are set according to the electric field concentration risks in different areas, avoiding insufficient margin in local weak areas due to the use of a uniform safety factor; improving the insulation reliability of the oil-SF6 composite outgoing interface. The oil-SF6 transition interface, bushing barrier, and lead outlet are treated as high-risk areas for separate verification and optimization, which helps reduce the risks of partial discharge, surface discharge, and interface breakdown; it takes into account AC, DC, impulse, and long-pulse operating conditions. Integrating multiple operating and experimental conditions into the electric field calculation process can more realistically reflect the insulation stress of the step-up transformer in the nuclear fusion accelerator power supply; forming a closed loop of design, simulation, optimization, and experimental verification. Based on the redundancy coefficient, weak insulation areas are located, and reverse optimization is performed on the oil gap, cardboard, grounding shield, lead wire, shielding, and bushing structure. Finally, the results are verified through withstand voltage and partial discharge tests, improving the feasibility of the project. This approach is conducive to the standardized design of equipment at multiple voltage levels and can be used for the unified redundancy design of step-up transformers with different DC potential levels of 200kV, 400kV, 600kV, 800kV, and 1000kV, taking into account insulation margin, structural compactness, and manufacturing consistency.

[0153] It should be understood that although the steps in the flowcharts of the above embodiments are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the above embodiments may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the steps or stages in other steps. It is understood that the steps in different embodiments can be freely combined as needed, and all non-contradictory solutions formed by such combinations are within the scope of protection of this application.

[0154] Based on the same inventive concept, this application also provides a step-up transformer insulation redundancy design device for implementing the above-mentioned step-up transformer insulation redundancy design method. The solution provided by this device is similar to the solution described in the above method; therefore, the specific limitations in one or more embodiments of the step-up transformer insulation redundancy design device provided below can be found in the limitations of the step-up transformer insulation redundancy design method described above, and will not be repeated here.

[0155] In one exemplary embodiment, such as Figure 7 As shown, a step-up transformer insulation redundancy design device is provided, including: an operating condition data acquisition module 710, a verification area determination module 720, an electric field strength calculation module 730, an insulation safety verification module 740, and an insulation structure adjustment module 750, wherein:

[0156] The operating condition data acquisition module 710 is used to acquire the operating condition boundary data of the step-up transformer to be designed.

[0157] The verification area determination module 720 is used to divide the step-up transformer into multiple insulation verification areas based on the insulation structure characteristics of the step-up transformer;

[0158] The electric field strength calculation module 730 is used to obtain the electric field strength of each insulation verification area under the various preset working conditions corresponding to the working condition boundary data when applying multiple preset working conditions to each of the insulation verification areas respectively.

[0159] The insulation safety verification module 740 is used to perform safety verification on each insulation verification area based on the electric field strength of each insulation verification area;

[0160] The insulation structure adjustment module 750 is used to obtain an adjustment method for the insulation structure of the insulation verification area when the safety verification of the insulation verification area fails, and after adjusting the insulation structure through the adjustment method, return to the step of obtaining the electric field strength of each insulation verification area under the various preset working conditions until the safety verification of each insulation verification area passes.

[0161] In one embodiment, the verification area determination module 720 is further configured to:

[0162] The two-dimensional and three-dimensional feature structures of the insulation structure of the step-up transformer are obtained; the two-dimensional feature structure includes the oil-paper composite insulation structure, winding arrangement and grounding structure, and the three-dimensional feature structure includes the lead wire outlet method and oil-SF6 bushing structure.

[0163] Based on the two-dimensional characteristic structure of the oil-paper composite insulation structure, the winding arrangement, and the grounding structure, the winding insulation area in the step-up transformer is determined.

[0164] Based on the lead-out method of the three-dimensional feature structure and the oil-SF6 bushing structure, the lead-out area, bushing barrier area and oil-SF6 transition interface area in the step-up transformer are determined.

[0165] The insulation verification area is determined based on the winding insulation area, the lead outlet area, the bushing barrier area, and the oil-SF6 transition interface area.

[0166] In one embodiment, the preset operating conditions include DC withstand voltage condition, long pulse operation condition, and AC withstand voltage condition; the electric field strength calculation module 730 is further used for:

[0167] Obtain the dielectric constant model and conductivity model of the insulating material in each of the insulation verification regions;

[0168] Under the preset operating conditions of DC withstand voltage condition or long pulse operation condition, the oil temperature data and winding temperature data of the step-up transformer after operation are obtained;

[0169] Based on the oil temperature data and the winding temperature data, determine the corresponding temperature correction parameters;

[0170] The conductivity model is updated based on the temperature correction parameters, and the corresponding electric field strength is obtained based on the updated conductivity model.

[0171] When the preset operating condition is AC withstand voltage condition, the corresponding electric field strength is obtained based on the dielectric constant model.

[0172] In one embodiment, the insulation safety verification module 740 is further configured to:

[0173] Obtain the withstand field strength of each insulation verification region;

[0174] Based on the withstand field strength and the corresponding electric field strength of each insulation verification region, the insulation redundancy coefficient of each insulation verification region is determined.

[0175] If the insulation redundancy coefficient is less than the insulation redundancy threshold corresponding to the insulation verification area, the safety verification of the corresponding insulation verification area is determined to have failed.

[0176] In one embodiment, the insulation redundancy threshold includes a first insulation redundancy threshold and a second insulation redundancy threshold; the insulation safety verification module 740 is further configured to:

[0177] When the insulation verification area includes at least one of the lead outlet area, the bushing barrier area, or the oil-SF6 transition interface area, the corresponding first insulation redundancy threshold is determined based on the three-dimensional feature attributes of the insulation verification area obtained in advance.

[0178] When the insulation verification area includes the winding insulation area, a corresponding second insulation redundancy threshold is determined based on the pre-acquired two-dimensional feature attributes of the insulation verification area; wherein, the first insulation redundancy threshold is higher than the second insulation redundancy threshold.

[0179] In one embodiment, the insulation structure adjustment module 750 is further configured to:

[0180] When the insulation verification area is an oil-SF6 transition interface area, the adjustment method is determined to be at least one of the following processes: adjusting the position of the shielding electrode of the oil-SF6 bushing associated with the oil-SF6 transition interface area, modifying the size of the equalizing ring, changing the bushing barrier length, adjusting the radius of the lead end fillet, and changing the lead bending radius.

[0181] Each module in the aforementioned step-up transformer insulation redundancy design device can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in the processor of a computer device in hardware form or independent of it, or stored in the memory of a computer device in software form, so that the processor can call and execute the corresponding operations of each module.

[0182] In one exemplary embodiment, a computer device is provided, which may be a terminal, and its internal structure diagram may be as follows: Figure 8As shown, the computer device includes a processor, memory, input / output interface, communication interface, display unit, and input device. The processor, memory, and input / output interface are connected via a system bus, and the communication interface, display unit, and input device are also connected to the system bus via the input / output interface. The processor provides computing and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system and computer programs. The internal memory provides an environment for the operation of the operating system and computer programs stored in the non-volatile storage media. The input / output interface is used for exchanging information between the processor and external devices. The communication interface is used for wired or wireless communication with external terminals; wireless communication can be achieved through Wi-Fi, mobile cellular networks, Near Field Communication (NFC), or other technologies. When the computer program is executed by the processor, it implements a method for designing insulation redundancy for a step-up transformer.

[0183] Those skilled in the art will understand that Figure 8 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0184] In one embodiment, a computer device is provided, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps in the above-described method embodiments.

[0185] In one embodiment, a computer-readable storage medium is provided having a computer program stored thereon, which, when executed by a processor, implements the steps in the above method embodiments.

[0186] In one embodiment, a computer program product is provided, including a computer program that, when executed by a processor, implements the steps in the above method embodiments.

[0187] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, data stored, data displayed, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of the relevant data must comply with relevant regulations.

[0188] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile memory and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM). The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, artificial intelligence (AI) processors, etc., and are not limited to these.

[0189] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this application.

[0190] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A method for designing insulation redundancy in a step-up transformer, characterized in that, The method includes: Obtain the operating boundary data of the step-up transformer to be designed; Based on the insulation structure characteristics of the step-up transformer, the step-up transformer is divided into multiple insulation verification areas; By applying multiple preset working conditions corresponding to the working condition boundary data to each of the insulation verification regions, the electric field strength of each of the insulation verification regions under the multiple preset working conditions is obtained. Based on the electric field strength of each insulation verification region, a safety verification is performed on each insulation verification region. If the safety check of the insulation check area fails, obtain the adjustment method for the insulation structure of the insulation check area, and after adjusting the insulation structure according to the adjustment method, return to the step of obtaining the electric field strength of each insulation check area under the various preset working conditions, until the safety check of each insulation check area passes.

2. The method according to claim 1, characterized in that, The safety verification of each insulation verification region based on the electric field strength of each insulation verification region includes: Obtain the withstand field strength of each insulation verification region; Based on the withstand field strength and the corresponding electric field strength of each insulation verification region, the insulation redundancy coefficient of each insulation verification region is determined. If the insulation redundancy coefficient is less than the insulation redundancy threshold corresponding to the insulation verification area, the safety verification of the corresponding insulation verification area is determined to have failed.

3. The method according to claim 2, characterized in that, Based on the insulation structure characteristics of the step-up transformer, the transformer is divided into multiple insulation verification areas, including: The two-dimensional and three-dimensional feature structures of the insulation structure of the step-up transformer are obtained; the two-dimensional feature structure includes the oil-paper composite insulation structure, winding arrangement and grounding structure, and the three-dimensional feature structure includes the lead wire outlet method and oil-SF6 bushing structure. Based on the two-dimensional characteristic structure of the oil-paper composite insulation structure, the winding arrangement, and the grounding structure, the winding insulation area in the step-up transformer is determined. Based on the lead-out method of the three-dimensional feature structure and the oil-SF6 bushing structure, the lead-out area, bushing barrier area and oil-SF6 transition interface area in the step-up transformer are determined. The insulation verification area is determined based on the winding insulation area, the lead outlet area, the bushing barrier area, and the oil-SF6 transition interface area.

4. The method according to claim 3, characterized in that, The insulation redundancy threshold includes a first insulation redundancy threshold and a second insulation redundancy threshold; The insulation redundancy threshold corresponding to each of the insulation verification areas is determined through the following steps: When the insulation verification area includes at least one of the lead outlet area, the bushing barrier area, or the oil-SF6 transition interface area, the corresponding first insulation redundancy threshold is determined based on the three-dimensional feature attributes of the insulation verification area obtained in advance. When the insulation verification area includes the winding insulation area, a corresponding second insulation redundancy threshold is determined based on the pre-acquired two-dimensional feature attributes of the insulation verification area; wherein, the first insulation redundancy threshold is higher than the second insulation redundancy threshold.

5. The method according to claim 1, characterized in that, The preset operating conditions include DC withstand voltage condition, long pulse operation condition, and AC withstand voltage condition; The step of obtaining the electric field strength of each insulation verification region under the various preset operating conditions corresponding to the operating condition boundary data when applying multiple preset operating conditions to each of the insulation verification regions includes: Obtain the dielectric constant model and conductivity model of the insulating material in each of the insulation verification regions; Under the preset operating conditions of DC withstand voltage condition or long pulse operation condition, the oil temperature data and winding temperature data of the step-up transformer after operation are obtained; Based on the oil temperature data and the winding temperature data, determine the corresponding temperature correction parameters; The conductivity model is updated based on the temperature correction parameters, and the corresponding electric field strength is obtained based on the updated conductivity model. When the preset operating condition is AC withstand voltage condition, the corresponding electric field strength is obtained based on the dielectric constant model.

6. The method according to any one of claims 1 to 5, characterized in that, The method for obtaining the adjustment of the insulation structure of the insulation verification area includes: When the insulation verification area is an oil-SF6 transition interface area, the adjustment method is determined to be at least one of the following processes: adjusting the position of the shielding electrode of the oil-SF6 bushing associated with the oil-SF6 transition interface area, modifying the size of the equalizing ring, changing the bushing barrier length, adjusting the radius of the lead end fillet, and changing the lead bending radius.

7. A step-up transformer insulation redundancy design device, characterized in that, The device includes: The operating condition data acquisition module is used to acquire the operating condition boundary data of the step-up transformer to be designed. The verification area determination module is used to divide the step-up transformer into multiple insulation verification areas based on the insulation structure characteristics of the step-up transformer; The electric field strength calculation module is used to obtain the electric field strength of each insulation verification area under the various preset working conditions corresponding to the working condition boundary data when applying multiple preset working conditions to each of the insulation verification areas respectively. An insulation safety verification module is used to perform safety verification on each insulation verification area based on the electric field strength of each insulation verification area; An insulation structure adjustment module is used to obtain an adjustment method for the insulation structure of the insulation verification area when the safety verification of the insulation verification area fails, and after adjusting the insulation structure according to the adjustment method, return to the step of obtaining the electric field strength of each insulation verification area under the various preset working conditions until the safety verification of each insulation verification area passes.

8. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the method according to any one of claims 1 to 6.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 6.

10. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 6.

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