Intelligent side expansion bus connector production process

Abstract

The invention relates to the technical field of side expansion bus connectors, in particular to an intelligent side expansion bus connector production process which comprises the following steps: S1, performing thermal management; s2, precisely arranging the sensors; s3, composite thermal field injection molding vulcanization; and S4, electric field gradient self-adaptive spraying is carried out. According to the invention, the periphery of the metal conductive core is coated with the phase change heat dissipation material in a mold pressing manner to form the inner core thermal buffering sleeve, so that active buffering of a temperature rise peak is realized; a distributed optical fiber sensor is spirally wound on the surface of an inner core thermal buffer sleeve to construct a state sensing layer, so that in-situ real-time monitoring of a temperature field and a stress field is realized. The insulation layer is synchronously vulcanized by adopting a microwave and infrared composite thermal field, so that the insulation uniformity is improved; through gradient spraying of the graphene shielding material, the electric field distribution is optimized. The problems that local overheat accumulation cannot be solved and the operation state cannot be known in the existing side expansion bus connector production process are solved.

Description

Technical Field

[0001] This invention relates to the field of side-expansion bus connector technology, and in particular to an intelligent side-expansion bus connector manufacturing process. Background Technology

[0002] In power transmission and distribution, rail transit, and industrial busbar systems, the reliability of side-expanded busbar connectors, as critical conductive connection devices, is paramount. With systems evolving towards higher voltage, higher current, and higher density, the Joule heat generated by side-expanded busbar connectors during operation is increasing dramatically. Overheating has become a major cause of accelerated insulation aging, increased contact resistance, and even failure.

[0003] Currently, common technical means in the industry to improve the heat dissipation capacity of side-expansion bus connectors mainly focus on external heat dissipation enhancement methods such as optimizing conductor cross-section, adding heat sink fins, or using high thermal conductivity potting compound. These methods improve heat dissipation conditions to some extent, but cannot fundamentally solve the problem of local overheating accumulation caused by instantaneous load fluctuations or abnormal local contact resistance. More importantly, side-expansion bus connectors manufactured by existing production processes are "passive components." Key state parameters such as the internal temperature field and stress field of side-expansion bus connectors cannot be sensed in real time, and their operating status is in a "black box" mode. They can only rely on periodic power outages for maintenance or simple surface temperature measurement for rough maintenance, which cannot predict latent faults or provide accurate data support for condition-based maintenance.

[0004] Therefore, designing an innovative manufacturing process that enables the construction of an efficient thermal buffer mechanism and embedded state sensing capabilities within the connector, thereby achieving in-situ monitoring and intelligent thermal management of key physical quantities, transforming "passive heat dissipation" into "active regulation," and "periodic maintenance" into "predictive maintenance," has become a pressing technical challenge to improve the intelligence level and operational reliability of high-end power equipment. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of existing technologies by providing an intelligent manufacturing process for side-expanding bus connectors. This process involves molding a phase-change heat dissipation material around the outer periphery of a metal conductive core to form an inner core thermal buffer sleeve, thus achieving active buffering of temperature rise spikes. Furthermore, a state-sensing layer is constructed by spirally winding distributed fiber optic sensors onto the surface of the inner core thermal buffer sleeve, enabling in-situ real-time monitoring of the temperature and stress fields. The process also employs microwave and infrared composite thermal fields to simultaneously vulcanize the insulation layer, improving insulation uniformity; and optimizes the electric field distribution through gradient spraying of graphene shielding material. This solves the problems of localized overheating accumulation and unknowable operating status inherent in existing side-expanding bus connector manufacturing processes.

[0006] To achieve the above objectives, the present invention provides an intelligent side-expansion bus connector manufacturing process, comprising the following steps:

[0007] Step S1: Thermal management preforming, using a molding process to coat the outer periphery of the metal conductive core with phase change heat dissipation material to form an inner core thermal buffer sleeve with heat storage function; Step S2: Precise sensor deployment. Distributed optical fiber sensors are spirally wound onto the surface of the inner core thermal buffer sleeve using an automated wrapping device and pre-fixed to construct a state sensing layer. Step S3: Composite thermal field injection molding and vulcanization. The pre-installed part with the sensor installed is placed into a microwave transparent mold. While the insulating material is being injected, a composite thermal field combining microwave heating and infrared radiation is used for synchronous vulcanization to form the main insulating layer. Step S4: Electric field gradient adaptive spraying. Graphene-modified shielding material is gradient-sprayed onto the outer surface of the vulcanized insulating main layer using plasma spraying equipment to form a non-uniformly distributed outer shielding layer.

[0008] Preferably, in step S1, The equivalent thermal diffusivity α of the phase change heat dissipation material within the phase change range satisfies the following condition: at the rated temperature rise rate, the ratio of the deviation between the phase change interface movement velocity of the phase change heat dissipation material and the radial thermal conduction velocity of the metal conductive core is less than 15%. The phase change heat dissipation material uses expanded graphite as a support skeleton. The expanded graphite support skeleton has an anisotropic three-dimensional network structure with a porosity of 85%-92% and a vacuum filling rate of more than 98% for the matrix material within the skeleton.

[0009] Preferably, in step S2, The tension F and the winding pitch P of the automated wrapping equipment satisfy the following relationship: ; Where F0 is the preset reference tension based on the minimum bending radius allowed by the distributed optical fiber sensor, and k is the compensation coefficient calculated in real time based on the curvature of the wrapping trajectory.

[0010] Preferably, in step S3, The microwave transparent mold is surrounded by multiple microwave emitting units for microwave heating arranged in a ring symmetrical distribution. By controlling the phase difference of each microwave emitting unit, a coherent superimposed microwave resonance mode is generated in the mold cavity. The microwave transparent mold has multiple sets of infrared lamps arranged along the axial direction for infrared radiation. By independently adjusting the radiation power of each infrared lamp set, the thermal stress gradient of the inner and outer walls of the insulating main body layer tends to be consistent.

[0011] Preferably, step S3 further includes closed-loop control logic, the specific steps of which include: Based on the temperature data collected by the distributed optical fiber sensor, the second derivative d of temperature with respect to time is calculated in real time. 2 T / dt 2 ; When d 2 T / dt 2 When a positive abrupt peak occurs, it is determined that the insulating material has entered a violent vulcanization and exothermic stage, and the output power of the microwave transmitting unit is automatically reduced accordingly.

[0012] Preferably, the step between step S3 and step S4 further includes: Step S3a: Self-healing buffer layer coating, coating the surface of the insulating main layer with a self-healing buffer layer containing insulating repair fluid microcapsules; Step S3b: Interfacial interpenetrating network formation. Using the residual heat from demolding after step S3, the contact interface between the self-healing buffer layer and the insulating main layer forms an interfacial interpenetrating network through molecular chain diffusion.

[0013] Preferably, in step S4, before plasma spraying, the following steps are also included: The outer surface of the insulating main layer is subjected to plasma activation treatment so that the fractal dimension Df of the surface roughness of the outer surface of the insulating main layer reaches the range of 2.2-2.5.

[0014] Preferably, step S4 further includes a real-time correction step, which specifically includes: The surface potential distribution spectrum of the coated area of ​​the outer shielding layer is obtained online using a charge scanning probe; when a local potential gradient is detected to exceed a preset threshold, the plasma spraying equipment is controlled to perform local adaptive replenishment spraying on the corresponding area.

[0015] Preferably, after step S4 is completed, the method further includes: Step S5: Fiber optic coupling and encapsulation. The fiber optic lead-out end of the distributed optical fiber sensor is encapsulated with high-strength polyimide and integrated with a precision flange interface to resist electromagnetic interference. Step S6, Signal Multiplexing and Acquisition: The packaged distributed optical fiber sensor synchronously acquires the high-frequency acoustic emission signal and low-frequency temperature rise signal sensed by the state perception layer through a single optical fiber link.

[0016] Preferably, it also includes a lifetime prediction step based on monitoring data: Step S7: Initial state tensor construction, extracting the energy entropy feature E of the high-frequency acoustic emission signal. entropy In conjunction with key data from the vulcanization process, a three-field coupled initial state tensor S0 characterizing the initial quality of the finished product is constructed, wherein the key data includes at least temperature uniformity and pressure skewness. Step S8, Lifetime Prediction and Risk Warning: Input the initial state tensor S0 into the trained lifetime prediction model to calculate the expected residual lifetime value L. res Simultaneously, the phase lag angle between the dynamic strain signal and the active thermal pulse excitation signal during operation was analyzed. The drift trend can be used to predict the risk of interface failure.

[0017] The beneficial effects of this invention are as follows: By molding and coating a phase-change heat dissipation material around the outer periphery of the metal conductive core to form an inner core thermal buffer sleeve, active buffering of temperature rise peaks is achieved; by constructing a state sensing layer by spirally winding a distributed optical fiber sensor on the surface of the inner core thermal buffer sleeve, in-situ real-time monitoring of the temperature and stress fields is realized. This process also employs microwave and infrared composite thermal field simultaneous vulcanization of the insulation layer, improving insulation uniformity; and by gradient spraying of graphene shielding material, the electric field distribution is optimized. This solves the problem that existing side-expansion bus connector manufacturing processes cannot address the issues of localized overheating accumulation and unknowable operating status. Attached Figure Description

[0018] Figure 1 This is a flowchart illustrating the steps of the present invention. Detailed Implementation

[0019] The present invention will now be described in detail with reference to the accompanying drawings.

[0020] like Figure 1 As shown, the intelligent side-expansion bus connector manufacturing process of the present invention includes the following steps: Step S1: Thermal management preforming. A phase change heat dissipation material is coated around the metal conductive core using a molding process to form an inner core thermal buffer sleeve with heat storage function. The molding process provides high pressure, ensuring the phase change heat dissipation material uniformly and densely wraps the metal conductive core. When the phase change heat dissipation material reaches its phase change temperature, it undergoes a phase change by absorbing latent heat, slowing down the temperature rise of itself and the surrounding medium. This forms an inner core thermal buffer sleeve with heat storage function, solving the problem of localized overheating accumulation and providing the first thermal buffer for the metal conductive core, smoothing out temperature rise peaks caused by instantaneous overload.

[0021] Step S2: Precise sensor deployment. Distributed fiber optic sensors are spirally wound onto the surface of the inner core thermal buffer sleeve using automated wrapping equipment and pre-fixed to construct a state-sensing layer. The spiral winding geometry enables the distributed fiber optic sensors to sense physical fields (such as temperature and strain) distributed along the connector axis. The pre-fixing process ensures the sensor's stable position in subsequent processes. The state-sensing layer constructed inside the side-expansion bus connector overcomes the "black box" limitation of the operating state and provides a physical basis for real-time monitoring of temperature and stress fields.

[0022] Step S3: Composite thermal field injection vulcanization. The pre-installed sensor component is placed into a microwave transparent mold. While the insulating material is being injected, a composite thermal field combining microwave heating and infrared radiation is used for simultaneous vulcanization to form the main insulating layer. Microwave heating enables the polar molecules of the insulating material to heat up rapidly and uniformly (volume heating), while infrared radiation provides a precise and controllable surface heat source. The combination of the two achieves simultaneous internal and external heating and vulcanization. This rapidly forms a dense and uniform insulating main layer, reducing internal defects and residual stress caused by large internal and external temperature differences in traditional vulcanization processes, and improving the long-term reliability of the insulation layer.

[0023] Step S4: Adaptive electric field gradient spraying. Using plasma spraying equipment, graphene-modified shielding material is gradient-sprayed onto the outer surface of the vulcanized insulating substrate, forming a non-uniformly distributed outer shielding layer. Plasma spraying generates a high-temperature, high-speed jet that melts and rapidly sprays the graphene-modified shielding material. The spraying thickness is controlled gradient-wise based on theoretical or experimental results of the electric field distribution on the insulating layer surface. This forms a non-uniformly distributed outer shielding layer, achieving electric field homogenization with optimal material usage, effectively suppressing partial discharge. Simultaneously, the high thermal conductivity of graphene assists in surface heat diffusion.

[0024] In the production process, firstly, a phase-change heat dissipation material is coated onto the outer periphery of the metal conductive core using a molding process to form an inner core heat buffer sleeve. Then, a distributed fiber optic sensor is spirally wound onto the surface of the inner core heat buffer sleeve using automated wrapping equipment and pre-fixed to construct a state sensing layer. Next, the sensor-deployed pre-built component is placed into a microwave-transparent mold. While injecting insulating material into the mold, a composite thermal field combining microwave heating and infrared radiation is activated to simultaneously vulcanize the insulating material, forming the main insulating layer. Finally, graphene-modified shielding material is gradient-sprayed onto the outer surface of the vulcanized main insulating layer using plasma spraying equipment to form a non-uniformly distributed outer shielding layer.

[0025] Specifically, the intelligent side-expansion bus connector has a clearly defined multi-layer radial stacked structure.

[0026] From the inside out: Core layer, a conductive metal core (such as copper or aluminum alloy).

[0027] Thermal Management / Buffer Layer: A thermal buffer sleeve made of phase change thermal material (PCM) tightly encasing the conductive core. The inner thermal buffer sleeve is made of composite material and serves both heat storage and structural support functions.

[0028] The sensing layer consists of distributed optical fiber sensors (such as FBG arrays or OFDR sensing fibers) spirally wound around the surface of the inner core thermal buffer sleeve, forming a stable state sensing layer through pre-fixed adhesive.

[0029] The insulating layer, formed by composite hot field injection molding and vulcanization, is the main insulating layer that completely encapsulates all the aforementioned inner layers. It is usually made of ethylene propylene rubber (EPDM) or silicone rubber.

[0030] The outer functional layer is a graphene-modified conductive shielding layer that is gradient-attached to the outer surface of the insulating host layer.

[0031] In this process, the phase change thermal material (PCM) also plays a "thermal damping" protective role. Specifically, during the composite thermal field vulcanization process in step S3, the exothermic cross-linking of the insulating rubber and microwave heating may generate localized high temperatures. The PCM layer in the pre-formed inner core thermal buffer sleeve (the phase change temperature point of the PCM, such as 58±2℃, is set within the vulcanization temperature window) plays a crucial role at this stage. When the local temperature exceeds the phase change point of the PCM, the PCM absorbs a large amount of latent heat (≥180J / g) and undergoes a solid-liquid phase change, effectively buffering and homogenizing the thermal shock, thus significantly reducing the temperature fluctuation rate of the microenvironment where the fiber optic sensor is located, which is in close contact with the inner core thermal buffer sleeve. This avoids thermal aging of the fiber optic coating, grating chirping, or failure, ensuring the survival and accuracy of the state sensing layer after the stringent process, which is a prerequisite for achieving "intelligentization".

[0032] The graphene shielding layer also plays a synergistic role in heat dissipation. Specifically, the graphene-modified shielding layer formed in step S4 not only provides excellent electromagnetic shielding, but its inherent high thermal conductivity (planar thermal conductivity > 1500 W / (m·K)) creates a radially efficient heat diffusion channel. During product operation, the heat absorbed by the internal metal conductive core and inner core thermal buffer sleeve can be conducted to the outer shielding layer through the insulating main body layer and rapidly and evenly distributed along the surface of the outer shielding layer, effectively reducing the overall thermal resistance of the connector and assisting the internal phase change heat dissipation material in completing thermal cycling (condensation heat release), thereby improving the system's continuous current carrying capacity and thermal stability. The inner core thermal buffer sleeve and the graphene-modified shielding layer form a synergistic thermal management architecture of "internal heat storage and buffering, and external efficient heat dissipation".

[0033] In step S1 of this embodiment, The equivalent thermal diffusivity α of the phase change heat dissipation material within the phase change range satisfies: At the rated temperature rise rate, the ratio of the deviation between the phase change interface movement velocity of the phase change heat dissipation material and the radial heat conduction velocity of the metal conductive core is less than 15%; the phase change interface movement velocity is controlled to basically match the radial heat conduction velocity of the metal conductive core. This ensures that the phase change heat absorption process and the metal conductive core heat generation process are coordinated, maximizing the latent heat utilization efficiency and preventing heat accumulation inside the phase change heat dissipation material.

[0034] The phase change heat dissipation material uses expanded graphite as a supporting framework. This framework exhibits an anisotropic three-dimensional network structure with a porosity of 85%-92%, and the vacuum filling rate of the matrix material within the framework is greater than 98%. The anisotropic network structure of the expanded graphite supporting framework provides channels and space for heat conduction and the volume expansion of the phase change material. High vacuum filling ensures that the matrix material fully wets the framework. This improves the overall thermal conductivity, structural stability, and long-term reliability of the phase change heat dissipation material.

[0035] To verify the thermal buffering effect of phase change thermal management material (PCM), a simulated operating temperature rise experiment was conducted. Two sets of conductor samples were prepared: one with an inner core thermal buffer sleeve and the other without. Temperature rise tests were performed under the same environmental conditions and current ratio (1.5 times the rated current). The experimental curves showed that the sample without the inner core thermal buffer sleeve reached a stable temperature of 105℃ within 15 minutes; while the sample with the inner core thermal buffer sleeve reached a stable temperature of 92℃ within 25 minutes, and the slope (heating rate) of the temperature rise curve was significantly flatter, with the maximum temperature reduced by approximately 12%. This indicates that the inner core thermal buffer sleeve effectively delayed the temperature rise process and reduced the steady-state temperature.

[0036] The vacuum filling rate is calculated using the mass comparison method. Specific steps include: First, accurately weigh the mass m of the porous expanded graphite support skeleton. s and volume V s The apparent density of the expanded graphite support skeleton was calculated and the porosity was estimated.

[0037] Then, after the prepared phase change heat dissipation material composite sample (paraffin / expanded graphite) was completely cured at low temperature, the total mass m was weighed. c Here, "low temperature" refers to a temperature below the melting point of the paraffin wax used, and the theoretical maximum filling mass of the base material (paraffin wax). .

[0038] Then the vacuum filling rate = (m c m s ) / m max ×100%. This method requires a dry testing environment to avoid the influence of moisture. A dry environment generally requires the relative humidity to be controlled below 40%RH.

[0039] The measured environment for the equivalent thermal diffusivity α is as follows: Measurements were performed using the laser flash method (LFA) in a standard laboratory environment (23±2℃, 50±10%RH). Samples were processed into circular discs with a diameter of 12.7 mm and a thickness of 1-3 mm, and the sample surface was graphitized to ensure light absorption.

[0040] During testing, record the temperature rise curve on the back of the sample and calculate the thermal diffusivity using the Cowan model or the method specified in ASTM E1461. For phase change heat dissipation materials, the change curves of the α value should be tested and recorded separately for the solid and liquid two-phase states and the phase transition range of the phase change heat dissipation material.

[0041] In step S2 of this embodiment The tension F and the winding pitch P of the automated wrapping equipment satisfy the following relationship: ; Where F0 is the preset reference tension based on the minimum allowable bending radius of the distributed optical fiber sensor, and k is the compensation coefficient calculated in real time based on the curvature of the winding trajectory. The tension is dynamically compensated based on the real-time curvature of the winding trajectory to ensure that the actual tension experienced by the distributed optical fiber sensor at the bend is not lower than the reference value for maintaining a good fit. This ensures that the distributed optical fiber sensor is in close contact with the surface of the inner core thermal buffer sleeve throughout the entire helical winding path, preventing damage caused by insufficient tension leading to sensor suspension or excessive tension.

[0042] F0 is the reference tension, determined based on the minimum permissible bending radius of the distributed fiber optic sensor (e.g., 30 mm) and the properties of the coating material. The purpose of F0 is to ensure that the distributed fiber optic sensor adheres tightly to the substrate without loosening during straight sections. A typical value for F0 ranges from 0.6 N to 0.8 N. The specific value is determined through preliminary experiments. Different tensions are applied around the sensor during straight sections, and after curing, the micro-bending loss of the distributed fiber optic sensor is measured. The tension with the lowest loss that does not cause coating damage is selected as F0.

[0043] k is the compensation coefficient, which is calculated dynamically in real time. Among them, R local R is the radius of curvature of the trajectory around the current position of the bun. avg Let η be the average radius of curvature of the entire wrapping path, and let η be an empirical constant related to the material friction coefficient and the stiffness of the distributed optical fiber sensor (η is usually on the order of 0.01 to 0.05).

[0044] When winding around to the connector's tapered section or bent interface, etc. local In smaller regions, the compensation coefficient k increases.

[0045] Traditional constant tension wrapping on complex curved surfaces (especially at abrupt curvature changes) can easily lead to microscopic slippage or local compression between the distributed fiber optic sensor and the substrate, generating "parasitic strain" that is not required for sensing. This results in initial zero-point drift and decreased long-term stability of the distributed fiber optic sensor. The tension compensation logic of this invention... By dynamically increasing the winding tension in high-curvature, small-pitch regions, the distributed fiber optic sensor is forced to fit more tightly to the curved surface profile, suppressing micro-slippage tendencies. This allows the distributed fiber optic sensor to be in a near-stress-free or "stress-known" baseline state immediately after the manufacturing process, greatly improving the accuracy and consistency of the initial signal and providing a reliable baseline for subsequent health monitoring.

[0046] In step S3 of this embodiment, multiple microwave emitting units for microwave heating are arranged symmetrically in a ring around the microwave transparent mold. By controlling the phase difference of each microwave emitting unit, coherent superimposed microwave resonant modes are generated within the mold cavity. By controlling the phase of the microwaves, specific standing wave or traveling wave modes with more uniform energy distribution are formed within the mold cavity. This achieves uniform heating of the insulating material, overcomes the inherent "hot spots" and "cold spots" problems of microwave heating, and improves the uniformity of vulcanization.

[0047] The microwave transparent mold has multiple sets of infrared lamps arranged axially for infrared radiation. By independently adjusting the radiation power of each infrared lamp set, the thermal stress gradient of the inner and outer walls of the insulating main body layer is made more uniform. By independently controlling the infrared radiation power at different axial positions, differences in axial heat dissipation caused by differences in mold shape or rubber thickness are compensated. This makes the thermal stress gradient of the inner and outer walls of the insulating main body layer more uniform during the vulcanization process, reducing axial warping deformation and internal stress.

[0048] Specifically, the core of the microwave transparent mold is made of microwave transparent material (such as quartz glass or special ceramics). Six to eight microwave emitting units (magnetrons) are evenly distributed around the outer circumference of the microwave transparent mold, forming a microwave phased array. By precisely adjusting the phase of the microwaves emitted by each microwave emitting unit through a central controller, a specific coherent superimposed standing wave field or rotating traveling wave field can be formed within the microwave transparent mold cavity, achieving three-dimensional volumetric uniform heating of the insulating material (microwave penetration heating).

[0049] For thick-walled or complex insulating substrates, single microwave heating may lead to internal overheating and insufficient external curing due to differences in dielectric loss or edge effects. This solution introduces multiple independently adjustable infrared lamp groups (peak wavelength of the infrared lamp groups ~2.0µm, matching the absorption peak of the insulating substrate) along the axial direction of the microwave transparent mold. Infrared radiation provides conductive heating from the surface inwards, effectively compensating for the lower temperatures at the ends and surfaces of the microwave transparent mold caused by heat dissipation. Through real-time temperature feedback, the control system dynamically adjusts the power of the infrared lamp groups in each axial segment, synchronizing the vulcanization reaction rate of the insulating substrate from the inside out and from the middle to the ends, minimizing the thermal stress gradient, and thus avoiding internal cracks, bubbles, or interface debonding caused by uneven curing.

[0050] This embodiment further includes closed-loop control logic in step S3, and the specific steps of the closed-loop control logic include: Based on the temperature data collected by the distributed optical fiber sensor, the second derivative d of temperature with respect to time is calculated in real time. 2 T / dt 2 ; When d 2 T / dt 2 When a positive abrupt peak occurs, it is determined that the insulating material has entered a violent vulcanization and exothermic stage, and the output power of the microwave transmitting unit is automatically reduced accordingly.

[0051] d 2 T / dt 2 The positive abrupt peak indicates that the insulating rubber compound has entered the intense exothermic vulcanization stage, at which point its own heat generation increases sharply. By actively reducing the energy input of external microwave heating through closed-loop control, local overheating caused by the superposition of the rubber compound's own exothermic heat and external heating is prevented, ensuring precise temperature control during the vulcanization process.

[0052] Traditional vulcanization control relies on external thermocouples on the mold, which suffers from thermal hysteresis (on the order of seconds) and low spatial resolution. This invention utilizes a built-in fiber Bragg grating (FBG) sensor network. The distributed fiber optic sensors have a temperature response time on the order of milliseconds and can provide the true temperature at multiple points along the conductor's axial and radial directions. Based on this high-speed, high-resolution temperature field data, d is calculated. 2 T / dt 2 It can accurately identify the inflection point of the vulcanization reaction several seconds to tens of seconds earlier than traditional methods, thereby enabling proactive adjustment of microwave power, avoiding overheating, ensuring vulcanization uniformity, and improving the uniformity and stability of the product's insulation performance.

[0053] This embodiment further includes the following step between step S3 and step S4: Step S3a: Self-healing buffer layer coating. A self-healing buffer layer containing microcapsules of insulating repair fluid is coated on the surface of the insulating main layer. When the insulating main layer develops microcracks due to external force, the crack propagation will puncture the microcapsules, releasing the repair fluid to fill the cracks. This endows the connector insulation layer with self-healing capabilities, improving its breakdown resistance and mechanical damage tolerance.

[0054] Step S3b: Interfacial Interpenetrating Network Formation. Utilizing the residual heat from demolding after step S3, an interfacial interpenetrating network is formed at the interface between the self-healing buffer layer and the insulating main layer through molecular chain diffusion. The residual heat from demolding provides sufficient kinetic energy to the molecular chains at the interface of the two materials, causing them to diffuse and entangle with each other. This significantly enhances the interfacial bonding strength between the self-healing buffer layer and the insulating main layer, prevents delamination, and improves the electrical properties at the interface.

[0055] Specifically, the self-healing buffer layer contains uniformly dispersed microcapsules. The shell material of the microcapsules is urea-formaldehyde resin or melamine resin, and the core material is a low-viscosity silicone-based insulating repair fluid. The particle size distribution of the microcapsules is 50~150µm, and the shell thickness is approximately 10% of the diameter. This specification ensures sufficient repair fluid storage while preventing premature rupture of the microcapsules during the encapsulation process.

[0056] To verify the strengthening effect of residual heat during demolding on the interface, a comparative experiment was conducted.

[0057] Group A: The self-healing buffer layer is coated under the residual heat of demolding (~90℃); Group B: Room temperature coating.

[0058] According to GB / T2791, a 180° peel test was conducted, and the peel strength of group A was on average more than 35% higher than that of group B. Simultaneously, according to GB / T1408.1, a power frequency withstand voltage test was conducted, and the interfacial breakdown voltage of group A samples was on average about 20% higher than that of group B. Analysis suggests that residual heat significantly promoted the interdiffusion and entanglement of molecular chain segments between the self-healing buffer layer polymer (such as silicone rubber) and the surface layer of the insulating host layer, forming a robust interpenetrating network (IPN). This not only enhanced the mechanical bonding force but also eliminated microscopic interfacial defects and improved the surface electrical strength.

[0059] In this embodiment, step S4, prior to plasma spraying, further includes: The outer surface of the insulating main layer is subjected to plasma activation treatment so that the fractal dimension Df of the surface roughness of the outer surface of the insulating main layer reaches the range of 2.2-2.5.

[0060] Plasma bombardment generates active groups on the surface of the insulating substrate and forms a micro-rough structure with specific fractal characteristics. This significantly increases the effective contact area and mechanical interlocking between the outer shielding layer and the insulating substrate, while providing more chemical bonding sites, thereby greatly enhancing the adhesion of the outer shielding layer.

[0061] Specifically, the fractal dimension Df is calculated using the box-counting dimension method. The specific steps are as follows: 1. Use laser confocal microscopy (LSCM) to obtain three-dimensional morphology data of the surface of the insulating substrate after plasma activation treatment (the surface area of ​​the insulating substrate is at least 100µm×100µm). 2. Binarize the topographic data into a height matrix. Select a series of square grids with different side lengths s to cover the surface contour projection of the insulating main layer; 3. Calculate the minimum number of boxes N(s) required to cover the outline of the main insulating layer; 4. In a double logarithmic coordinate system, plot the data points with log(1 / s) as the x-axis and logN(s) as the y-axis; 5. Perform linear fitting on the data points, and the slope of the resulting line is the fractal dimension Df.

[0062] Comparing plasma-activated (Df=2.35) and untreated (Df≈2.05) samples, cross-cut adhesion tests (1mm spacing) were conducted according to GB / T9286. The untreated sample showed an outer shielding layer peeling area greater than 5% (grade ≤2), while the plasma-activated sample showed a peeling area less than 1% (grade ≥4), indicating significantly improved adhesion. The high Df value surface possesses a more complex microstructure, providing better mechanical interlocking (anchoring) for the graphene-modified shielding material particles.

[0063] The plasma activation treatment performed on the outer surface of the insulating substrate layer before plasma spraying in step S4 specifically includes the following steps: For surface pretreatment, the vulcanized insulating base layer (such as EPDM material) is ultrasonically cleaned with anhydrous ethanol to remove surface oil and dust, and then dried at 60°C.

[0064] The processing apparatus and parameters are as follows: A clean and dry insulating substrate is placed in the vacuum chamber of the radio frequency (RF) plasma processing equipment. After the chamber pressure is evacuated to below 10 Pa, a mixture of argon and oxygen is introduced as the working gas, with a volume ratio of argon to oxygen of (4:1) to (9:1). The RF power is set to 100-300 W, the processing time to 30-180 seconds, and the electrode spacing is maintained within the range of 20-50 mm.

[0065] The processing mechanism involves the plasma (including high-energy electrons, ions, and reactive free radicals) generated under these parameters bombarding and acting on the surface of the insulating substrate, producing a dual effect: Physical etching involves high-energy particle bombardment that breaks down the polymer molecular chains on the surface, creating a microscopic uneven structure that increases surface roughness.

[0066] Chemical modification introduces polar functional groups such as hydroxyl (-OH) and carboxyl (-COOH) groups onto the surface through reactive oxygen free radicals, significantly improving the surface energy.

[0067] The combined effect of the aforementioned physical and chemical processes results in the formation of an active layer with a specific and complex microstructure on the surface of the insulating substrate. Through this treatment, the fractal dimension (Df) of its surface roughness can be controlled within the target range of 2.2-2.5. This surface, with its high Df value and polar functional groups, provides extremely strong mechanical anchoring points and excellent chemical wetting properties for the subsequent spraying of graphene-modified shielding material, making it a crucial pretreatment step to ensure high adhesion of the outer shielding layer.

[0068] Step S4 in this embodiment further includes a real-time correction step, which specifically includes: The surface potential distribution spectrum of the coated area of ​​the outer shielding layer is obtained online using a charge scanning probe; when a local potential gradient is detected to exceed a preset threshold, the plasma spraying equipment is controlled to perform local adaptive replenishment spraying on the corresponding area.

[0069] An abnormal surface potential gradient directly reflects insufficient shielding layer thickness or defects in that region, leading to uneven electric field distribution. Online quality monitoring and real-time process compensation during the outer shielding layer fabrication process were achieved, ensuring that the final shielding layer possesses a highly uniform electric field homogenization capability.

[0070] Specifically, the control system compares the surface potential distribution map of the coated area of ​​the outer shielding layer with an ideal uniform distribution model, and identifies local potential gradients that exceed a preset threshold V. th The "hot zone" (i.e., the weak shielding area) is 80V / mm. The supplementary spraying algorithm performs the following steps: Regional localization and rasterization: The "hot zone" is rasterized in the robot's working coordinate system and divided into multiple spray unit grids.

[0071] The trajectory planning is based on the original spraying trajectory, and a slow reciprocating scanning subroutine is inserted on the path segment corresponding to the "hot zone". In the slow reciprocating scanning subroutine, the robot nozzle will perform an additional 1-3 round trips of spraying on the hot zone at 50%-70% of the original moving speed.

[0072] Dynamic adjustments are made, and after completing one round of touch-up spraying, the potential is scanned again. If the "hot zone" is not eliminated, the number of reciprocating scans in the slow reciprocating scan subroutine is increased proportionally or the moving speed is decreased, depending on the magnitude of the residual potential deviation. This iterative process continues until the potential gradient meets the target, achieving closed-loop spraying quality control based on surface electrical performance feedback.

[0073] This embodiment further includes the following after step S4 is completed: Step S5: Fiber optic coupling and encapsulation. The fiber optic pigtail of the distributed fiber optic sensor is encapsulated with high-strength polyimide and integrated with a precision flange interface to resist electromagnetic interference. The polyimide encapsulation provides high-strength protection, and the precision flange interface ensures stable connection and shields against external electromagnetic interference. This protects the fragile fiber optic pigtail interface and ensures the long-term reliability and signal integrity of the signal output channel in harsh industrial environments.

[0074] Step S6, Signal Multiplexing and Acquisition: The encapsulated distributed optical fiber sensor synchronously acquires the high-frequency acoustic emission signal and low-frequency temperature rise signal sensed by the state sensing layer through a single optical fiber link. Utilizing the different modulation mechanisms of optical fibers for physical signals of different frequencies, multiplexed transmission of multi-parameter signals is achieved within the same optical fiber. This simplifies the system structure and enables synchronous, in-situ monitoring of two key fault symptoms: partial discharge (high-frequency acoustic emission) and overheating (low-frequency temperature rise) inside the side expansion bus connector.

[0075] Specifically, the point where the pigtail of the distributed fiber optic sensor exits from the graphene-modified shielding layer is a point of electric field concentration and creepage risk. The packaging process is as follows: First, a stepped buffer groove is machined on the insulating main layer of the outlet.

[0076] Then, the pigtail segment is encapsulated with a high-strength, high-thermal-conductivity insulating adhesive (such as epoxy resin filled with alumina) to form a polyimide outer coating.

[0077] Finally, a metal braided mesh sleeve with the same potential as the outer shielding layer is tightly fitted onto the outer layer of the package, and connected to the external monitoring equipment through a precision flange interface.

[0078] This design achieves a smooth potential transition, with the metal braided mesh sleeve dissipating surface leakage current and the stepped buffer groove extending the creepage path, effectively preventing partial discharge.

[0079] Preferably, the demodulation module employs a combination of wavelength division multiplexing (WDM) and time division multiplexing (TDM) techniques. For temperature rise signals (low frequency, 0-10Hz), this is achieved by monitoring the slow drift of the FBG center wavelength. For partial discharge acoustic emission signals (high frequency, 20k-200kHz), the dynamic strain generated by the partial discharge acoustic emission signal causes instantaneous broadening of the FBG reflection spectrum and power fluctuations.

[0080] The demodulation module incorporates a high-speed photoelectric converter and a digital signal processor (DSP) to perform Fast Fourier Transform (FFT) and filtering on the received optical signal. By setting high-pass and low-pass digital filters, the optical power fluctuation component reflecting high-frequency vibration and the center wavelength component reflecting low-frequency temperature change are separated in the frequency domain, and then demodulated and analyzed separately, thereby decoupling the two types of physical signals, temperature and acoustic emission, from a single optical fiber link.

[0081] This embodiment also includes a lifetime prediction step based on monitoring data: Step S7: Initial state tensor construction, extracting the energy entropy feature E of the high-frequency acoustic emission signal. entropyBy combining key data from the vulcanization process, a three-field coupled initial state tensor S0 characterizing the initial quality of the finished product is constructed. The key data includes at least temperature uniformity and pressure skewness. The initial performance indicators of the finished product under the three physical fields of "electricity, heat, and force" are coupled and quantified to form a comprehensive, multi-dimensional initial health state benchmark. This provides a precise data foundation for differentiated lifetime prediction based on initial quality.

[0082] Step S8, Lifetime Prediction and Risk Warning: Input the initial state tensor S0 into the trained lifetime prediction model to calculate the expected residual lifetime value L. res Simultaneously, the phase lag angle between the dynamic strain signal and the active thermal pulse excitation signal during operation was analyzed. The drift trend is used to predict the risk of interface failure. The lifetime prediction model learns the correlation between the initial state and the final lifetime from historical data; phase hysteresis angle. The drift reflects the degradation of the bonding state at the material interface. This represents a leap from "periodic maintenance" to "predictive maintenance," enabling early prediction of interface failure risks and providing a basis for precise maintenance decisions.

[0083] Specifically, the tensor S0 is a feature vector that integrates information from the electrical, thermal, and mechanical fields. It includes: Electrical / thermal field characteristics, temperature uniformity index and peak vulcanization temperature monitored by FBG during the vulcanization process.

[0084] Force / sound field characteristics: After wavelet packet decomposition, the energy entropy E of the lower-line acoustic emission signal in the 100-200kHz frequency band. entropy And the skewness of the sulfidation pressure curve (reflecting the asymmetry of pressure fluctuations).

[0085] In practice, other key parameters may also be included, such as the uniformity of potential distribution after the shielding layer is sprayed and / or the test value of the interface peel strength (sampling).

[0086] Collect a large amount of historical production data (S0) and the corresponding product failure times in accelerated aging tests. Use random forest regression or support vector regression (SVR) algorithms to train and establish a mapping model from S0 to accelerated life. The training process automatically learns the weighted weights of each parameter, such as energy entropy E. entropy Samples with low (more defects) and poor temperature uniformity will have higher weights, indicating a shorter lifespan. Finally, the trained model is combined with the classical Arrhenius equation to calculate L under rated operating conditions. res .

[0087] A standard thermal pulse is applied to the connectors operating online periodically (e.g., quarterly), and the dynamic strain response phase hysteresis angle is measured. (benchmark value) 0 (Measured during initial installation). Two-level early warning system is set: Primary warning: When detected three times consecutively >1.1 When the deviation is 0 (i.e., the deviation exceeds 10%), the system marks the connector as an "object of concern" and recommends shortening the inspection cycle in the next inspection.

[0088] Advanced warning / inspection command triggered: When detected >1.25 0 or If the value experiences a rapid, non-linear increase (e.g., an increase of more than 5% within a week), the system automatically generates and issues an "emergency inspection command." The emergency inspection command alerts maintenance personnel that the connector interface may have experienced initial debonding or aging and hardening, requiring a detailed inspection after a power outage, thus achieving a closed loop from condition monitoring to preventative maintenance.

[0089] The above description is only a preferred embodiment of the present invention. For those skilled in the art, there will be changes in the specific implementation and application scope based on the ideas of the present invention. The content of this specification should not be construed as a limitation of the present invention.

Claims

1. An intelligent manufacturing process for side-expanding busbar connectors, characterized in that, Includes the following steps: Step S1: Thermal management preforming, using a molding process to coat the outer periphery of the metal conductive core with phase change heat dissipation material to form an inner core thermal buffer sleeve with heat storage function; Step S2: Precise sensor deployment. Distributed optical fiber sensors are spirally wound onto the surface of the inner core thermal buffer sleeve using an automated wrapping device and pre-fixed to construct a state sensing layer. Step S3: Composite thermal field injection molding and vulcanization. The pre-installed part with the sensor installed is placed into a microwave transparent mold. While the insulating material is being injected, a composite thermal field combining microwave heating and infrared radiation is used for synchronous vulcanization to form the main insulating layer. Step S4: Electric field gradient adaptive spraying. Graphene-modified shielding material is gradient-sprayed onto the outer surface of the vulcanized insulating main layer using plasma spraying equipment to form a non-uniformly distributed outer shielding layer.

2. The intelligent side-expansion bus connector manufacturing process according to claim 1, characterized in that, In step S1, The equivalent thermal diffusivity α of the phase change heat dissipation material within the phase change range satisfies the following condition: at the rated temperature rise rate, the ratio of the deviation between the phase change interface movement velocity of the phase change heat dissipation material and the radial thermal conduction velocity of the metal conductive core is less than 15%. The phase change heat dissipation material uses expanded graphite as a support skeleton. The expanded graphite support skeleton has an anisotropic three-dimensional network structure with a porosity of 85%-92% and a vacuum filling rate of more than 98% for the matrix material within the skeleton.

3. The intelligent side-expansion bus connector manufacturing process according to claim 1, characterized in that, In step S2, The tension F and the winding pitch P of the automated wrapping equipment satisfy the following relationship: ； Where F0 is the preset reference tension based on the minimum bending radius allowed by the distributed optical fiber sensor, and k is the compensation coefficient calculated in real time based on the curvature of the wrapping trajectory.

4. The intelligent side-expansion bus connector manufacturing process according to claim 1, characterized in that, In step S3, The microwave transparent mold is surrounded by multiple microwave emitting units for microwave heating arranged in a ring symmetrical distribution. By controlling the phase difference of each microwave emitting unit, a coherent superimposed microwave resonance mode is generated in the mold cavity. The microwave transparent mold has multiple sets of infrared lamps arranged along the axial direction for infrared radiation. By independently adjusting the radiation power of each infrared lamp set, the thermal stress gradient of the inner and outer walls of the insulating main body layer tends to be consistent.

5. The intelligent side-expansion bus connector manufacturing process according to claim 4, characterized in that, Step S3 also includes closed-loop control logic, the specific steps of which include: Based on the temperature data collected by the distributed optical fiber sensor, the second derivative d of temperature with respect to time is calculated in real time. 2 T / dt 2 ; When d 2 T / dt 2 When a positive abrupt peak occurs, it is determined that the insulating material has entered a violent vulcanization and exothermic stage, and the output power of the microwave transmitting unit is automatically reduced accordingly.

6. The intelligent side-expansion bus connector manufacturing process according to claim 1, characterized in that, Between step S3 and step S4, the following is also included: Step S3a: Self-healing buffer layer coating, coating the surface of the insulating main layer with a self-healing buffer layer containing insulating repair fluid microcapsules; Step S3b: Interfacial interpenetrating network formation. Using the residual heat from demolding after step S3, the contact interface between the self-healing buffer layer and the insulating main layer forms an interfacial interpenetrating network through molecular chain diffusion.

7. The intelligent side-expansion bus connector manufacturing process according to claim 1, characterized in that, In step S4, the process before plasma spraying also includes: The outer surface of the insulating main layer is subjected to plasma activation treatment so that the fractal dimension Df of the surface roughness of the outer surface of the insulating main layer reaches the range of 2.2-2.

5.

8. The intelligent side-expansion bus connector manufacturing process according to claim 1 or 7, characterized in that, Step S4 further includes a real-time correction step, which specifically includes: The surface potential distribution spectrum of the coated area of ​​the outer shielding layer is obtained online using a charge scanning probe; when a local potential gradient is detected to exceed a preset threshold, the plasma spraying equipment is controlled to perform local adaptive replenishment spraying on the corresponding area.

9. The intelligent side-expansion bus connector manufacturing process according to claim 1, characterized in that, After step S4 is completed, the following is also included: Step S5: Fiber optic coupling and encapsulation. The fiber optic lead-out end of the distributed optical fiber sensor is encapsulated with high-strength polyimide and integrated with a precision flange interface to resist electromagnetic interference. Step S6, Signal Multiplexing and Acquisition: The packaged distributed optical fiber sensor synchronously acquires the high-frequency acoustic emission signal and low-frequency temperature rise signal sensed by the state perception layer through a single optical fiber link.

10. The intelligent side-expansion bus connector manufacturing process according to claim 9, characterized in that, It also includes a lifetime prediction step based on monitoring data: Step S7: Initial state tensor construction, extracting the energy entropy feature E of the high-frequency acoustic emission signal. entropy In conjunction with key data from the vulcanization process, a three-field coupled initial state tensor S0 characterizing the initial quality of the finished product is constructed, wherein the key data includes at least temperature uniformity and pressure skewness. Step S8, Lifetime Prediction and Risk Warning: Input the initial state tensor S0 into the trained lifetime prediction model to calculate the expected residual lifetime value L. res Simultaneously, the phase lag angle between the dynamic strain signal and the active thermal pulse excitation signal during operation was analyzed. The drift trend can be used to predict the risk of interface failure.

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