In Xinjiang,China,Oil-immersed paper bushings used in reactors are highly susceptible to discharge breakdown faults due to drastic fluctuations in environmental and oil temperatures.To mitigate this problem,oil-free a...In Xinjiang,China,Oil-immersed paper bushings used in reactors are highly susceptible to discharge breakdown faults due to drastic fluctuations in environmental and oil temperatures.To mitigate this problem,oil-free and explosion-proof epoxy resin-impregnated paper(ERIP)bushings are recommended as replacements.This study develops a multi-physics(electric-thermal-fluid)coupling model for 750 kV high voltage reactors ERIP bushings.The model aims to comprehensively assess their thermal and electrical performance under extreme ambient temperatures ranging from−40℃ to 90℃ and oil temperatures varying from−10℃ to 90℃.The results demonstrate that the bushing temperature rises consistently with increases in ambient temperature.Additionally,the location of the hottest point on the conductive rod exhibits an upward shift as the ambient temperature climbs.Significantly,when a temperature difference exists between the oil and the external environment,this upward movement remains relatively constrained.Even when the external temperature increases from−40℃ to 80℃,the hottest point shifts upward only 2457 mm.Conversely,in the absence of a temperature difference between the oil and external environment,a modest 10℃ increase in ambient temperature(from 80℃ to 90℃)triggers a substantial 11,356 mm upward displacement of the hottest point.Moreover,this study reveals that the electric field distribution within the bushings remains largely unaffected by environmental temperature changes.展开更多
The influences of power spinning process parameters on the mechanical properties of spinning parts were analyzed with an SXD100/3-CNC numerical control power spinning machine.The unidirectional tensile tests were carr...The influences of power spinning process parameters on the mechanical properties of spinning parts were analyzed with an SXD100/3-CNC numerical control power spinning machine.The unidirectional tensile tests were carried out.Based on the experimental data,a ternary quadratic regression equation was established by orthogonal experiment.The Ramberg-Osgood constitutive model of tin-bronze connecting rod bushing was obtained.Referred to the constitutive relation of macroscopic incremental,the incremental elastoplastic constitutive relation of spinning parts was deduced based on the Mises yield criterion and kinematic hardening model.The results can be applied to the elastoplastic analysis in finite element numerical simulation.展开更多
Design and optimization of bushing at present mainly use the traditional experience method.The relevant research that adopts computer simulation to carry on the operation behavior of the bushing has appeared in recent...Design and optimization of bushing at present mainly use the traditional experience method.The relevant research that adopts computer simulation to carry on the operation behavior of the bushing has appeared in recent years.How to use the finite element method to research bushing was introduced in the article.Physics fields and many relevant parameters of one real bushing were calculated.Through the results of calculation,it indicate that the finite element method is very useful in bushing research of designing and optimizing.展开更多
Cemented and mechanically clamped types of end fittings(fitting-C and fitting-M)are commonly used in transformer bushings.During the Luding Ms 6.8 earthquake that occurred in China on September 5,2022,all transformer ...Cemented and mechanically clamped types of end fittings(fitting-C and fitting-M)are commonly used in transformer bushings.During the Luding Ms 6.8 earthquake that occurred in China on September 5,2022,all transformer bushings with the two types of end fittings in a 500 kV substation were damaged.Post-earthquake field investigations were conducted,and the failures of the two types of bushings were compared.Two elementary simulation models of the transformer-bushing systems were developed to simulate the engineering failures,and further compute their seismic responses for comparison.The results indicate that the hitch lugs of the connection flange are structurally harmful to seismic resistance.Fitting-M can decrease the bending stiffness of the bushing due to the flexible sealing rubber gasket.Since it provides a more flexible connection that dissipates energy,the peak accelerations and relative displacements at the top of the bushing are significantly lower than those of the bushing with fitting-C.Compared with fitting-C,fitting-M transfers the high-stress areas from the connection flange to the root of the porcelain,so the latter becomes the most vulnerable component.Fitting-M increases the failure risk of the low-strength porcelain,indicating the unsuitability of applying it in high-intensity fortification regions.展开更多
The numerical simulation for temperature distribution of Pt-Rh alloy bushing was carried out using a thermal-electric module in ANSYS Workbench finite element analysis software.The effects of side wall thickness,plug ...The numerical simulation for temperature distribution of Pt-Rh alloy bushing was carried out using a thermal-electric module in ANSYS Workbench finite element analysis software.The effects of side wall thickness,plug thickness,the angle of two side walls and electrode structure on the uniformity of temperature distribution were investigated.Meanwhile,the contrastive analysis results of bushing with and without glass melt were discussed.The simulation results show that,when the homogeneous glass melt flows through bushing,the temperature difference between the center and both ends of bushing is decreased significantly,but the temperature distribution at both ends of bushing is still affected by heating non-uniformity of bushing.Compared with side wall thickness,plug thickness and the angle of two side walls,electrode structure plays a greater role in adjusting heating uniformity of bushing.展开更多
In this paper,glass fibers were prepared by centrifugal-spinneret-blow(CSB) process.The molten glass got different flow rate from 390 kg/h to 270 kg/h by adjusting the electric current of platinum/10 rhodium alloy bus...In this paper,glass fibers were prepared by centrifugal-spinneret-blow(CSB) process.The molten glass got different flow rate from 390 kg/h to 270 kg/h by adjusting the electric current of platinum/10 rhodium alloy bushing.The diameter and microstructure of glass fibers have been investigated by scanning electron microscopy(SEM) and vertical optical microscope(VOM).The results indicated that the flow rate of molten glass was proportional to the diameter of glass fibers when the molten glass got main flow rate of 330 kg/h.The lower the flow rate was,the finer the average diameter was.展开更多
In recent years, the deficiencies of ceramic insulators along with their high maintenance costs have resulted in the replacement of ceramic insulators with silicon type in the pollution area. This idea has been employ...In recent years, the deficiencies of ceramic insulators along with their high maintenance costs have resulted in the replacement of ceramic insulators with silicon type in the pollution area. This idea has been employed for more than two decades in the polluted areas. Humidity of the weather in the south of Iran and the presence of pollutants in the air have made special conditions for construction and maintenance of some equipment including transformer bushings. Usual ceramic bushings, due to their ability in absorbing pollution and the rapid reduction of creepage distance (in a limited time period), have reduced transformer disconnection severely as a result of earth fault. Additionally, they are costly to be washed regularly. Therefore, using intelligent materials in designing bushing can increase the reliability of network and consequently reduction of costs. In this regard, this paper investigates the use of silicon bushings in the distribution systems and proposes operational ideas for the optimal operation of these devices in the polluted areas. The sample bushing was evaluated based on the IEC60137 standard test.展开更多
A design of a slot bushing with a volumetric field has been developed, which allows to produce continuous fibers from melts with difficult processing characteristics in order to produce fibers with better operating ch...A design of a slot bushing with a volumetric field has been developed, which allows to produce continuous fibers from melts with difficult processing characteristics in order to produce fibers with better operating characteristics. The operability of the design was confirmed when solving two problems of special technological complexity. 1. 400 and 800 orifice bushings for production of continuous fibers from the basalt melt have been developed and recommended for manufacture. 2. The process of production of continuous fibers from standard glass using 2400 orifice bushing with perforated plates instead of orifice tips without air cooling, has been realized for the first time.展开更多
Inspired by the safe landing of cats falling from high altitudes,a bionic flexible rubber bushing structure is proposed and its motion characteristics are systematically studied to explore its potential application in...Inspired by the safe landing of cats falling from high altitudes,a bionic flexible rubber bushing structure is proposed and its motion characteristics are systematically studied to explore its potential application in the suppression of vibration.The convex hull structure on the bushing surface is abstracted from the cat’s claw pad,and the hyper-viscoelastic model is selected as the constitutive model of the rubber material.In addition,the design with the best vibration damping effect is finally obtained by reasonably adjusting the amount of radial compression and distribution of bionic structures.Finally,under the same conditions,the test results of the dynamic characteristics of the bushing verify the accuracy of the simulation results.Research results show that the convex hull bionic structure designed in this paper can effectively change the motion characteristics of the rubber bushing under various working conditions,which provides new inspiration or potential possibility for the design of rubber bushing in the future.展开更多
Taking the rubber torsion bushing of a certain type of all-terrain tracked vehicle as the research object,a theoretical model of torsional stiffness was proposed according to the non-linear characteristics of rubber c...Taking the rubber torsion bushing of a certain type of all-terrain tracked vehicle as the research object,a theoretical model of torsional stiffness was proposed according to the non-linear characteristics of rubber components and structural feature of the suspension. Simulations were carried out under different working conditions to obtain root mean square of vertical weighted acceleration as the evaluation index for ride performance of the all-terrain tracked vehicle,with a dynamics model of the whole vehicle based on the theoretical model of the torsional stiffness and standard road roughness as excitation input. Response surface method was used to establish the parametric optimization model of the torsional stiffness. The evaluation index showed that ride performance of the vehicle with optimized torsional stiffness model of suspension was improved compared with previous model fromexperiment. The torsional stiffness model of rubber bushing provided a theoretical basis for the design of the rubber torsion bushing in light tracked vehicles.展开更多
The press-fit connector is a typical plug-and-play solderless connection,and it is widely used in signal transmission in fields such as communication and automotive devices.This paper focuses on inverse designing and ...The press-fit connector is a typical plug-and-play solderless connection,and it is widely used in signal transmission in fields such as communication and automotive devices.This paper focuses on inverse designing and optimization of geometric structure,as well as insertion-withdrawal forces of press-fit connector using artificial neural network(ANN)-assisted optimization method.The ANN model is established to approximate the relationship between geometric parameters and insertion-withdrawal forces,of which hyper-parameters of neural network are optimized to improve model performance.Two numerical methods are proposed for inverse designing structural parameters(Model-I)and multi-objective optimization of insertion-withdrawal forces(Model-II)of press-fit connector.In Model-I,a method for inverse designing structure parameters is established,of which an ANN model is coupled with single-objective optimization algorithm.The objective function is established,the inverse problem is solved,and effectiveness is verified.In Model-II,a multi-objective optimization method is proposed,of which an ANN model is coupled with genetic algorithm.The Pareto solution sets of insertion-withdrawal forces are obtained,and results are analyzed.The established ANN-coupled numerical optimization methods are beneficial for improving the design efficiency,and enhancing the connection reliability of the press-fit connector.展开更多
Presents the study on the pressure and friction fields of the lubricant film on the surface of a large thrust elastic metal plastic bearing bush in a hydraulic turbine using the method of finite element analysis and t...Presents the study on the pressure and friction fields of the lubricant film on the surface of a large thrust elastic metal plastic bearing bush in a hydraulic turbine using the method of finite element analysis and the stress and displacement fields in the vertical direction of the bush surface obtained to provide a theoretical basis for the design of contour lines and investigation into the causes for destruction of bushes, and concludes with test results that 1) the stress on the surface of the bush is not uniform; 2) a tension stress tends to occur near the oil ingress and egress edges but it is minor; 3) the biggest displacement in the vertical direction appears where x=84 and Y=1 153 and has a value of 0.022 mm; 4) the deformation of the bearing bush is harmful to the maintenance of lubricant film.展开更多
The temperature of bush inner surface temperature is measured by using infrared thermometer and transparent bearing,and temperature rise is measured by using thermocouple. The influence of rotating speed and axial loc...The temperature of bush inner surface temperature is measured by using infrared thermometer and transparent bearing,and temperature rise is measured by using thermocouple. The influence of rotating speed and axial location on the bush inner surface temperature is studied,and the influence of supply pressure and rotating speed on the temperature rise is analyzed. The results show the bush inner surface temperature and temperature rise of spiral oil wedge hydrodynamic bearing increase with the increase of rotation speed. In axial direction,the temperature is higher around the oil return hole. The temperature rise decreases with the increase of supply pressure. The highest temperature of bush inner surface and temperature rise are higher at higher speed,so the temperature rise is the fundamental reason which restricts the increase of rotation speed for high speed sleeve bearing.展开更多
基金supported by the Reliability Improvement Technology and Application of Epoxy Impregnated Paper Bushing in Extreme Environments under granted DQ30DK24001P.
文摘In Xinjiang,China,Oil-immersed paper bushings used in reactors are highly susceptible to discharge breakdown faults due to drastic fluctuations in environmental and oil temperatures.To mitigate this problem,oil-free and explosion-proof epoxy resin-impregnated paper(ERIP)bushings are recommended as replacements.This study develops a multi-physics(electric-thermal-fluid)coupling model for 750 kV high voltage reactors ERIP bushings.The model aims to comprehensively assess their thermal and electrical performance under extreme ambient temperatures ranging from−40℃ to 90℃ and oil temperatures varying from−10℃ to 90℃.The results demonstrate that the bushing temperature rises consistently with increases in ambient temperature.Additionally,the location of the hottest point on the conductive rod exhibits an upward shift as the ambient temperature climbs.Significantly,when a temperature difference exists between the oil and the external environment,this upward movement remains relatively constrained.Even when the external temperature increases from−40℃ to 80℃,the hottest point shifts upward only 2457 mm.Conversely,in the absence of a temperature difference between the oil and external environment,a modest 10℃ increase in ambient temperature(from 80℃ to 90℃)triggers a substantial 11,356 mm upward displacement of the hottest point.Moreover,this study reveals that the electric field distribution within the bushings remains largely unaffected by environmental temperature changes.
基金Project(2012011023-2)supported by the Natural Science Foundation of Shanxi Province,China
文摘The influences of power spinning process parameters on the mechanical properties of spinning parts were analyzed with an SXD100/3-CNC numerical control power spinning machine.The unidirectional tensile tests were carried out.Based on the experimental data,a ternary quadratic regression equation was established by orthogonal experiment.The Ramberg-Osgood constitutive model of tin-bronze connecting rod bushing was obtained.Referred to the constitutive relation of macroscopic incremental,the incremental elastoplastic constitutive relation of spinning parts was deduced based on the Mises yield criterion and kinematic hardening model.The results can be applied to the elastoplastic analysis in finite element numerical simulation.
基金National Science Foundation of China Yunnan United Foundation.(U0837601)the Natural Science Foundation of Yunnan Province,China(2010CF126)
文摘Design and optimization of bushing at present mainly use the traditional experience method.The relevant research that adopts computer simulation to carry on the operation behavior of the bushing has appeared in recent years.How to use the finite element method to research bushing was introduced in the article.Physics fields and many relevant parameters of one real bushing were calculated.Through the results of calculation,it indicate that the finite element method is very useful in bushing research of designing and optimizing.
基金National Natural Science Foundation of China under Grant No.51878508。
文摘Cemented and mechanically clamped types of end fittings(fitting-C and fitting-M)are commonly used in transformer bushings.During the Luding Ms 6.8 earthquake that occurred in China on September 5,2022,all transformer bushings with the two types of end fittings in a 500 kV substation were damaged.Post-earthquake field investigations were conducted,and the failures of the two types of bushings were compared.Two elementary simulation models of the transformer-bushing systems were developed to simulate the engineering failures,and further compute their seismic responses for comparison.The results indicate that the hitch lugs of the connection flange are structurally harmful to seismic resistance.Fitting-M can decrease the bending stiffness of the bushing due to the flexible sealing rubber gasket.Since it provides a more flexible connection that dissipates energy,the peak accelerations and relative displacements at the top of the bushing are significantly lower than those of the bushing with fitting-C.Compared with fitting-C,fitting-M transfers the high-stress areas from the connection flange to the root of the porcelain,so the latter becomes the most vulnerable component.Fitting-M increases the failure risk of the low-strength porcelain,indicating the unsuitability of applying it in high-intensity fortification regions.
基金Funded by the State Key Laboratory of Silicate Materials for Architectures(Wuhan University of Technology)(No.SYSJJ2019-21)the National Key Research and Development Program of China(No.2016YFB0303700)。
文摘The numerical simulation for temperature distribution of Pt-Rh alloy bushing was carried out using a thermal-electric module in ANSYS Workbench finite element analysis software.The effects of side wall thickness,plug thickness,the angle of two side walls and electrode structure on the uniformity of temperature distribution were investigated.Meanwhile,the contrastive analysis results of bushing with and without glass melt were discussed.The simulation results show that,when the homogeneous glass melt flows through bushing,the temperature difference between the center and both ends of bushing is decreased significantly,but the temperature distribution at both ends of bushing is still affected by heating non-uniformity of bushing.Compared with side wall thickness,plug thickness and the angle of two side walls,electrode structure plays a greater role in adjusting heating uniformity of bushing.
文摘In this paper,glass fibers were prepared by centrifugal-spinneret-blow(CSB) process.The molten glass got different flow rate from 390 kg/h to 270 kg/h by adjusting the electric current of platinum/10 rhodium alloy bushing.The diameter and microstructure of glass fibers have been investigated by scanning electron microscopy(SEM) and vertical optical microscope(VOM).The results indicated that the flow rate of molten glass was proportional to the diameter of glass fibers when the molten glass got main flow rate of 330 kg/h.The lower the flow rate was,the finer the average diameter was.
文摘In recent years, the deficiencies of ceramic insulators along with their high maintenance costs have resulted in the replacement of ceramic insulators with silicon type in the pollution area. This idea has been employed for more than two decades in the polluted areas. Humidity of the weather in the south of Iran and the presence of pollutants in the air have made special conditions for construction and maintenance of some equipment including transformer bushings. Usual ceramic bushings, due to their ability in absorbing pollution and the rapid reduction of creepage distance (in a limited time period), have reduced transformer disconnection severely as a result of earth fault. Additionally, they are costly to be washed regularly. Therefore, using intelligent materials in designing bushing can increase the reliability of network and consequently reduction of costs. In this regard, this paper investigates the use of silicon bushings in the distribution systems and proposes operational ideas for the optimal operation of these devices in the polluted areas. The sample bushing was evaluated based on the IEC60137 standard test.
文摘A design of a slot bushing with a volumetric field has been developed, which allows to produce continuous fibers from melts with difficult processing characteristics in order to produce fibers with better operating characteristics. The operability of the design was confirmed when solving two problems of special technological complexity. 1. 400 and 800 orifice bushings for production of continuous fibers from the basalt melt have been developed and recommended for manufacture. 2. The process of production of continuous fibers from standard glass using 2400 orifice bushing with perforated plates instead of orifice tips without air cooling, has been realized for the first time.
基金The authors gratefully acknowledge the financial supports from the Jilin Provincial Scientific and Technological Department(20220201123GX).
文摘Inspired by the safe landing of cats falling from high altitudes,a bionic flexible rubber bushing structure is proposed and its motion characteristics are systematically studied to explore its potential application in the suppression of vibration.The convex hull structure on the bushing surface is abstracted from the cat’s claw pad,and the hyper-viscoelastic model is selected as the constitutive model of the rubber material.In addition,the design with the best vibration damping effect is finally obtained by reasonably adjusting the amount of radial compression and distribution of bionic structures.Finally,under the same conditions,the test results of the dynamic characteristics of the bushing verify the accuracy of the simulation results.Research results show that the convex hull bionic structure designed in this paper can effectively change the motion characteristics of the rubber bushing under various working conditions,which provides new inspiration or potential possibility for the design of rubber bushing in the future.
文摘Taking the rubber torsion bushing of a certain type of all-terrain tracked vehicle as the research object,a theoretical model of torsional stiffness was proposed according to the non-linear characteristics of rubber components and structural feature of the suspension. Simulations were carried out under different working conditions to obtain root mean square of vertical weighted acceleration as the evaluation index for ride performance of the all-terrain tracked vehicle,with a dynamics model of the whole vehicle based on the theoretical model of the torsional stiffness and standard road roughness as excitation input. Response surface method was used to establish the parametric optimization model of the torsional stiffness. The evaluation index showed that ride performance of the vehicle with optimized torsional stiffness model of suspension was improved compared with previous model fromexperiment. The torsional stiffness model of rubber bushing provided a theoretical basis for the design of the rubber torsion bushing in light tracked vehicles.
基金supported by the National Natural Science Foundation of China(No.52005378)the opening project fund of Materials Service Safety Assessment Facilities(No.MSAF-2021-107).
文摘The press-fit connector is a typical plug-and-play solderless connection,and it is widely used in signal transmission in fields such as communication and automotive devices.This paper focuses on inverse designing and optimization of geometric structure,as well as insertion-withdrawal forces of press-fit connector using artificial neural network(ANN)-assisted optimization method.The ANN model is established to approximate the relationship between geometric parameters and insertion-withdrawal forces,of which hyper-parameters of neural network are optimized to improve model performance.Two numerical methods are proposed for inverse designing structural parameters(Model-I)and multi-objective optimization of insertion-withdrawal forces(Model-II)of press-fit connector.In Model-I,a method for inverse designing structure parameters is established,of which an ANN model is coupled with single-objective optimization algorithm.The objective function is established,the inverse problem is solved,and effectiveness is verified.In Model-II,a multi-objective optimization method is proposed,of which an ANN model is coupled with genetic algorithm.The Pareto solution sets of insertion-withdrawal forces are obtained,and results are analyzed.The established ANN-coupled numerical optimization methods are beneficial for improving the design efficiency,and enhancing the connection reliability of the press-fit connector.
文摘Presents the study on the pressure and friction fields of the lubricant film on the surface of a large thrust elastic metal plastic bearing bush in a hydraulic turbine using the method of finite element analysis and the stress and displacement fields in the vertical direction of the bush surface obtained to provide a theoretical basis for the design of contour lines and investigation into the causes for destruction of bushes, and concludes with test results that 1) the stress on the surface of the bush is not uniform; 2) a tension stress tends to occur near the oil ingress and egress edges but it is minor; 3) the biggest displacement in the vertical direction appears where x=84 and Y=1 153 and has a value of 0.022 mm; 4) the deformation of the bearing bush is harmful to the maintenance of lubricant film.
基金Sponsored by the National Natural Science Foundation of China(Grant No.51305242)the Scientific Research Foundation of Shandong University of Science and Technology for Recruited Talents(Grant No.2013RCJJ014)
文摘The temperature of bush inner surface temperature is measured by using infrared thermometer and transparent bearing,and temperature rise is measured by using thermocouple. The influence of rotating speed and axial location on the bush inner surface temperature is studied,and the influence of supply pressure and rotating speed on the temperature rise is analyzed. The results show the bush inner surface temperature and temperature rise of spiral oil wedge hydrodynamic bearing increase with the increase of rotation speed. In axial direction,the temperature is higher around the oil return hole. The temperature rise decreases with the increase of supply pressure. The highest temperature of bush inner surface and temperature rise are higher at higher speed,so the temperature rise is the fundamental reason which restricts the increase of rotation speed for high speed sleeve bearing.
