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
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 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
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
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
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
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
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
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
Ultra-high-voltage direct current wall bushings are critical components in direct current transmission systems.Temperature variations and abnormal distributions can signal potential equipment failures that threaten sy...Ultra-high-voltage direct current wall bushings are critical components in direct current transmission systems.Temperature variations and abnormal distributions can signal potential equipment failures that threaten system stability.Therefore,monitoring these critical multi-point temperature variations is essential.However,the unique design of the bushings,featuring insulation sheds of periodic shape,distorts infrared temperature measurements by introducing interference points.These interference points,dependent on the measurement's angle and distance,appear irregularly in infrared images,severely impacting the accuracy of multi-point temperature distribution assessments.To address this challenge,an anomaly detection method is proposed that adaptively identifies interference points.The method identifies interference points by comparing pixels and uses a voting mechanism to improve identification accuracy.Compared with traditional methods,this approach presents two main advantages:adaptive identification capability,which enables it to recognise interference points and adapt to changing conditions,and unsupervised learning,which enables it to work effectively without requiring manually labelled data.Experimental tests on 161 bushing infrared images demonstrate the effectiveness of the method,achieving a 100%success rate in identifying localised overheating issues.The method has been integrated into high-voltage direct current transmission anomaly systems and can be used to monitor critical equipment,enhancing system reliability and safety.展开更多
As an important component of oil-immersed transformers,the bushing's internal insu-lation ageing and dampness after the long-term operation can cause changes in the in-ternal electric and temperature fields,seriou...As an important component of oil-immersed transformers,the bushing's internal insu-lation ageing and dampness after the long-term operation can cause changes in the in-ternal electric and temperature fields,seriously threatening its safe operation.This paper tested the power frequency permittivity and direct current conductivity of aged and damp oil-paper insulation samples at different testing temperatures,and constructed a dynamic dielectric parameter calculation model.Meanwhile,a simulation model was established based on the actual structure of the 252 kV/1250 A bushing which is mainly used for the oil-immersed high-voltage bushings of 110 kV and above.The electric-magnetic-thermal multi-physical fields were used for simulation analysis.The influence of ageing/moisture(different degrees of dampness in the upper and lower regions)on the electric field distribution in the bushing was obtained.During the initial to steady-state process,the electric field distribution at the zero and end shield shows a reversal phenomenon.When the capacitor core has different degrees of dampness in the upper and lower regions,the impedance distribution of the capacitor core is non-uniform.This phenomenon will lead to an increase in the radial electric field gradient at the end shield of the capacitor core,which is prone to the risk of slip-flashing discharge.In summary,this paper adopts the field-induced dynamic parameters method to analyse the changes of multi-physical fields in the bushing.This can provide theoretical guidance for optimising the bushing structure and on-site maintenance.展开更多
Operation level and service life of oil-immersed bushings are related to the moisture inside theirs cellulose insulation. However, the parameters extracted by using existing frequency domain spectroscopy (FDS) based m...Operation level and service life of oil-immersed bushings are related to the moisture inside theirs cellulose insulation. However, the parameters extracted by using existing frequency domain spectroscopy (FDS) based methods strongly depends on the data within a certain range or several sampling points, which could decrease the accuracy of extraction results if the measured FDS data is unreliable in the above regions. Given this issue, a universal and accessible tool is proposed to stimulate the change rule of FDS curves versus entire frequency regions, by which a set of feature parameters can be readily obtained by using the Taylor series model. Then, the database characterizing the moisture is established. An alternative method for evaluating the moisture in bushing cellulose insulation is proposed based on FDS and grey relational analysis (GRA). The feasibility and applicability of the proposed methods were later proved by the moisture evaluation of transformer oil-immersed bushings, in which the G RA is applied as a tool for moisture classification. The results showed that the average relative (absolute error) is less than 14.6% (0.17%). Thus, the proposed method can be preliminarily utilized for evaluating the moisture inside the bushing cellulose insulation.展开更多
Elaeagnaceae Juss. belongs to the family Elaeagnus L. and Shepherdia Nutt. This study aims at the significance and vegetative reproduction of species of the family (Elaeagnus macrophylla Thunb. and Shepherdia canadens...Elaeagnaceae Juss. belongs to the family Elaeagnus L. and Shepherdia Nutt. This study aims at the significance and vegetative reproduction of species of the family (Elaeagnus macrophylla Thunb. and Shepherdia canadensis (L.) Nutt.) in the national economy. The trials were carried out in the experimental site of SamSU’s Botanic Garden, which is named after Sharof Rashidov. The study’s findings are based on the results obtained by planting cuttings of S. canadensis and E. macrophylla species of varying sizes and durations, as well as the cuttings’ roots and the impacts of growth chemicals.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.
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.
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National Natural Science Foundation of China,Grant/Award Numbers:62106033,42367066。
文摘Ultra-high-voltage direct current wall bushings are critical components in direct current transmission systems.Temperature variations and abnormal distributions can signal potential equipment failures that threaten system stability.Therefore,monitoring these critical multi-point temperature variations is essential.However,the unique design of the bushings,featuring insulation sheds of periodic shape,distorts infrared temperature measurements by introducing interference points.These interference points,dependent on the measurement's angle and distance,appear irregularly in infrared images,severely impacting the accuracy of multi-point temperature distribution assessments.To address this challenge,an anomaly detection method is proposed that adaptively identifies interference points.The method identifies interference points by comparing pixels and uses a voting mechanism to improve identification accuracy.Compared with traditional methods,this approach presents two main advantages:adaptive identification capability,which enables it to recognise interference points and adapt to changing conditions,and unsupervised learning,which enables it to work effectively without requiring manually labelled data.Experimental tests on 161 bushing infrared images demonstrate the effectiveness of the method,achieving a 100%success rate in identifying localised overheating issues.The method has been integrated into high-voltage direct current transmission anomaly systems and can be used to monitor critical equipment,enhancing system reliability and safety.
基金National Natural Science Foundation of China,Grant/Award Number:52307164Heilongjiang Provincial Natural Science Foundation of China,Grant/Award Number:YQ2024E044。
文摘As an important component of oil-immersed transformers,the bushing's internal insu-lation ageing and dampness after the long-term operation can cause changes in the in-ternal electric and temperature fields,seriously threatening its safe operation.This paper tested the power frequency permittivity and direct current conductivity of aged and damp oil-paper insulation samples at different testing temperatures,and constructed a dynamic dielectric parameter calculation model.Meanwhile,a simulation model was established based on the actual structure of the 252 kV/1250 A bushing which is mainly used for the oil-immersed high-voltage bushings of 110 kV and above.The electric-magnetic-thermal multi-physical fields were used for simulation analysis.The influence of ageing/moisture(different degrees of dampness in the upper and lower regions)on the electric field distribution in the bushing was obtained.During the initial to steady-state process,the electric field distribution at the zero and end shield shows a reversal phenomenon.When the capacitor core has different degrees of dampness in the upper and lower regions,the impedance distribution of the capacitor core is non-uniform.This phenomenon will lead to an increase in the radial electric field gradient at the end shield of the capacitor core,which is prone to the risk of slip-flashing discharge.In summary,this paper adopts the field-induced dynamic parameters method to analyse the changes of multi-physical fields in the bushing.This can provide theoretical guidance for optimising the bushing structure and on-site maintenance.
基金supported in part by the National Natural Science Foundation of China under Grant 51867003in part by the Natural Science Foundation of Guangxi under Grant 2018JJB160064 and 2018JJA160176in part by Guangxi Key Laboratory of Power System Optimization and Energy Technology Project under Grant AE3020001829。
文摘Operation level and service life of oil-immersed bushings are related to the moisture inside theirs cellulose insulation. However, the parameters extracted by using existing frequency domain spectroscopy (FDS) based methods strongly depends on the data within a certain range or several sampling points, which could decrease the accuracy of extraction results if the measured FDS data is unreliable in the above regions. Given this issue, a universal and accessible tool is proposed to stimulate the change rule of FDS curves versus entire frequency regions, by which a set of feature parameters can be readily obtained by using the Taylor series model. Then, the database characterizing the moisture is established. An alternative method for evaluating the moisture in bushing cellulose insulation is proposed based on FDS and grey relational analysis (GRA). The feasibility and applicability of the proposed methods were later proved by the moisture evaluation of transformer oil-immersed bushings, in which the G RA is applied as a tool for moisture classification. The results showed that the average relative (absolute error) is less than 14.6% (0.17%). Thus, the proposed method can be preliminarily utilized for evaluating the moisture inside the bushing cellulose insulation.
文摘Elaeagnaceae Juss. belongs to the family Elaeagnus L. and Shepherdia Nutt. This study aims at the significance and vegetative reproduction of species of the family (Elaeagnus macrophylla Thunb. and Shepherdia canadensis (L.) Nutt.) in the national economy. The trials were carried out in the experimental site of SamSU’s Botanic Garden, which is named after Sharof Rashidov. The study’s findings are based on the results obtained by planting cuttings of S. canadensis and E. macrophylla species of varying sizes and durations, as well as the cuttings’ roots and the impacts of growth chemicals.
