The Experts below are selected from a list of 324 Experts worldwide ranked by ideXlab platform
Zongren Peng - One of the best experts on this subject based on the ideXlab platform.
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research on the deterioration process of electrical contact structure inside the 500 kv converter transformer rip Bushings and its prediction strategy
Iet Generation Transmission & Distribution, 2019Co-Authors: Huidong Tian, Qingyu Wang, Shiyi Zhou, Zehua Wu, Jinyin Zhang, Zongren PengAbstract:Extra high-voltage converter transformer resin impregnated paper (RIP) bushing is used as the outlet device of the converter transformer, its safe operation is directly related to the reliability of the power system. Under the long-term effects of high current, strong mechanical stress and abrasion, the contact resistance of connection structure inside the bushing is prone to deteriorate. When the local overheating increases to a certain level, the insulation performance of bushing will decline and may lead to penetrating discharge. Therefore, it is vital to develop strategies for predicting the overheating fault of RIP Bushings. In this study, firstly, one typical overheating fault of RIP bushing induced by the contact deterioration was diagnosed according to the fretting corrosive model and SF 6 decomposition process. Secondly, using the three-dimensional electromagnetic-thermal-fluid finite element method, the temperature distributions of RIP bushing under the different overheating degrees were simulated. Finally, based on the maintenance experience and simulation results, the diagnosis strategies were proposed. The diagnosis principle and prediction strategies were successfully helped to maintain the faulted RIP Bushings and wall Bushings before a destructive overheating accident could occur, which provide a basic reference for the fault prediction and improvements of relative standards.
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Research on the deterioration process of electrical contact structure inside the ±500 kV converter transformer RIP Bushings and its prediction strategy
IET Generation Transmission & Distribution, 2019Co-Authors: Huidong Tian, Qingyu Wang, Shiyi Zhou, Zehua Wu, Jinyin Zhang, Zongren PengAbstract:Extra high-voltage converter transformer resin impregnated paper (RIP) bushing is used as the outlet device of the converter transformer, its safe operation is directly related to the reliability of the power system. Under the long-term effects of high current, strong mechanical stress and abrasion, the contact resistance of connection structure inside the bushing is prone to deteriorate. When the local overheating increases to a certain level, the insulation performance of bushing will decline and may lead to penetrating discharge. Therefore, it is vital to develop strategies for predicting the overheating fault of RIP Bushings. In this study, firstly, one typical overheating fault of RIP bushing induced by the contact deterioration was diagnosed according to the fretting corrosive model and SF6 decomposition process. Secondly, using the three-dimensional electromagnetic-thermal-fluid finite element method, the temperature distributions of RIP bushing under the different overheating degrees were simulated. Finally, based on the maintenance experience and simulation results, the diagnosis strategies were proposed. The diagnosis principle and prediction strategies were successfully helped to maintain the faulted RIP Bushings and wall Bushings before a destructive overheating accident could occur, which provide a basic reference for the fault prediction and improvements of relative standards.
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Study on frequency domain dielectric spectroscopy of epoxy resin impregnated paper Bushings under damp conditions
The Journal of Engineering, 2019Co-Authors: Zuoming Xu, Wei Hu, Fuquan Yi, Guanpeng Hu, Xin Wang, Zongren PengAbstract:Epoxy resin impregnated paper (RIP) Bushings are widely used as transformer Bushings and wall Bushings, but this type of bushing is easy to be dampened. In order to study the effect of moisture on the Bushings' insulation performance, a test device was established to simulate the moisture absorption process in the air or N2 gas. Based on the frequency-domain dielectric spectroscopy (FDS) method, FDS curves that indicate the dielectric loss factor (tan δ) and capacitance (C) under different frequencies were tested and analysed. The results demonstrated that the FDS curve moves to the high frequency direction with the increase of the moisture content, and there exist minus tan δ and a negative peak in low-frequency band. Since the moisture content is much lower than in the air, tan δ and C under power frequency of the bushing almost unchanged in the N2 gas. However, the tan δ under 0.1 Hz increases sharply with the increase of trace moisture, and the higher moisture content, the greater increase rate. A damp diagnosis method for RIP Bushings is proposed based on the FDS curves' frequency translation characteristics and tan δ variation law. Also the results can give references for RIP Bushings' insulation diagnosis.
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Influence of Aluminum Foil and External Conductor on the Temperature Distribution of RIP Condenser Converter Transformer Bushings
2018 IEEE Conference on Electrical Insulation and Dielectric Phenomena (CEIDP), 2018Co-Authors: Xi Yang, Qingyu Wang, Zongren PengAbstract:With the increase of capacity, it's imperative to research about the 3-D temperature distribution regularity of transformer converter Bushings. However, the influence of aluminum foil plates and heat generation power of external conductor on the temperature distribution of Bushings has usually been neglected. In this paper, using the computational fluid dynamics (CFD) and finite element method (FEM) analysis method, the 3-D temperature distribution of the converter transformer bushing will be simulated according to the actual operating environment by considering the effect of the aluminum foil plates and the heat generation of the external conductor. The research indicates that the aluminum foil plates have little influence to the temperature distribution of RIP Bushings. The thickness of external conductor should be reduced as much as possible, and try to choose materials with larger resistivity to reduce alternating eddy current loss of the external conductor and improve the bushing temperature distribution.
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Numerical Calculation of Static Temperature Distribution of Transformer Bushings and Analysis of Influential Factors
2018 IEEE International Conference on High Voltage Engineering and Application (ICHVE), 2018Co-Authors: Zehua Wu, Huidong Tian, Shiyi Zhou, Liu Peng, Haoran Wang, Zongren PengAbstract:Transformer resin impregnated paper(RIP) bushing has been widely applied in power transmission system as a vital part of power transformer. The performance of bushing is important to the reliability level and stability of power system. However, as the voltage level increases, the heating problem of resin impregnated paper bushing is increasingly serious. In this paper, a 3-D electromagnetic-fluid-thermal method was proposed by applying computational fluid dynamics(CFD) analysis. The influence of thermal conduction, thermal radiation and convection heat transfer were taken into account and take the resistivity varying with temperature in consideration. The distribution of temperature was obtained; influential factors of environmental temperature, oil temperature and thermal conductivity of resin impregnated paper and sheath were investigated. The highest temperature is located at the interface between the central conductor and resin impregnated paper core. The effect law of different factors to the temperature distribution could provide reference for the thermal design of Bushings.
Milad Akbari - One of the best experts on this subject based on the ideXlab platform.
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heat analysis of the power transformer Bushings in the transient and steady states considering the load variations
Applied Thermal Engineering, 2017Co-Authors: Milad Akbari, Mehdi Allahbakhshi, Rashid MahmoodianAbstract:Abstract Bushings are considered as one of the main components of the power transformers. This is due to the fact that the reliable and efficient performance of the Bushings significantly influences the reliability of the transformers which, in turn, are counted as the fundamental part of the power systems. The thermal behaviour of the Bushings, as a consequence of the power dissipation, significantly affects the bushing’s performance and design. In this paper, a novel algorithm is proposed for the heat analysis of the Bushings. This algorithm aims at specifying the hot spot temperature and the temperature distribution of the bushing. Therefore, the problem is formulated using the Joule Heating equations as the partial differential equations for both transient and steady states. Then, the finite element method is employed to solve the problem. The algorithm is implemented on an oil-impregnated paper bushing. In the steady state, the temperature distribution of the whole bushing is determined. In addition, the effects of different currents on the location and magnitude of the hot spot temperature have been investigated. In the transient state, three overload scenarios are simulated two of which are from the IEEE C57.19.100 and IEC 60076-7 standards. In addition, the effects of the wind speed and electric load on the bushing’s temperature distribution for 48 h have been investigated.
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heat analysis of the power transformer Bushings using the finite element method
Applied Thermal Engineering, 2016Co-Authors: Mehdi Allahbakhshi, Milad AkbariAbstract:Abstract Reliability of power transformers significantly depends on the performance of their Bushings and bushing lifetime is mainly dependent on its hottest spot temperature, which is caused by the power dissipation in the bushing's conductor. In this paper, the thermal analysis of the bushing is firstly performed in two-dimensional space using the differential equations. Then, the Finite Element Method (FEM) is employed to determine a bushing's temperature distribution and specify its hottest spot. The effects of increasing the temperature on the bushing's conductor are also investigated and the results are compared in different currents. The proposed method calculates the temperature distribution in all parts of bushing including conductor surface, paper, porcelain and oil. It is useful for manufacturer and utilities to evaluate the insulation design, temperature distribution and loss of insulation life.
Rashid Mahmoodian - One of the best experts on this subject based on the ideXlab platform.
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heat analysis of the power transformer Bushings in the transient and steady states considering the load variations
Applied Thermal Engineering, 2017Co-Authors: Milad Akbari, Mehdi Allahbakhshi, Rashid MahmoodianAbstract:Abstract Bushings are considered as one of the main components of the power transformers. This is due to the fact that the reliable and efficient performance of the Bushings significantly influences the reliability of the transformers which, in turn, are counted as the fundamental part of the power systems. The thermal behaviour of the Bushings, as a consequence of the power dissipation, significantly affects the bushing’s performance and design. In this paper, a novel algorithm is proposed for the heat analysis of the Bushings. This algorithm aims at specifying the hot spot temperature and the temperature distribution of the bushing. Therefore, the problem is formulated using the Joule Heating equations as the partial differential equations for both transient and steady states. Then, the finite element method is employed to solve the problem. The algorithm is implemented on an oil-impregnated paper bushing. In the steady state, the temperature distribution of the whole bushing is determined. In addition, the effects of different currents on the location and magnitude of the hot spot temperature have been investigated. In the transient state, three overload scenarios are simulated two of which are from the IEEE C57.19.100 and IEC 60076-7 standards. In addition, the effects of the wind speed and electric load on the bushing’s temperature distribution for 48 h have been investigated.
Mehdi Allahbakhshi - One of the best experts on this subject based on the ideXlab platform.
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heat analysis of the power transformer Bushings in the transient and steady states considering the load variations
Applied Thermal Engineering, 2017Co-Authors: Milad Akbari, Mehdi Allahbakhshi, Rashid MahmoodianAbstract:Abstract Bushings are considered as one of the main components of the power transformers. This is due to the fact that the reliable and efficient performance of the Bushings significantly influences the reliability of the transformers which, in turn, are counted as the fundamental part of the power systems. The thermal behaviour of the Bushings, as a consequence of the power dissipation, significantly affects the bushing’s performance and design. In this paper, a novel algorithm is proposed for the heat analysis of the Bushings. This algorithm aims at specifying the hot spot temperature and the temperature distribution of the bushing. Therefore, the problem is formulated using the Joule Heating equations as the partial differential equations for both transient and steady states. Then, the finite element method is employed to solve the problem. The algorithm is implemented on an oil-impregnated paper bushing. In the steady state, the temperature distribution of the whole bushing is determined. In addition, the effects of different currents on the location and magnitude of the hot spot temperature have been investigated. In the transient state, three overload scenarios are simulated two of which are from the IEEE C57.19.100 and IEC 60076-7 standards. In addition, the effects of the wind speed and electric load on the bushing’s temperature distribution for 48 h have been investigated.
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heat analysis of the power transformer Bushings using the finite element method
Applied Thermal Engineering, 2016Co-Authors: Mehdi Allahbakhshi, Milad AkbariAbstract:Abstract Reliability of power transformers significantly depends on the performance of their Bushings and bushing lifetime is mainly dependent on its hottest spot temperature, which is caused by the power dissipation in the bushing's conductor. In this paper, the thermal analysis of the bushing is firstly performed in two-dimensional space using the differential equations. Then, the Finite Element Method (FEM) is employed to determine a bushing's temperature distribution and specify its hottest spot. The effects of increasing the temperature on the bushing's conductor are also investigated and the results are compared in different currents. The proposed method calculates the temperature distribution in all parts of bushing including conductor surface, paper, porcelain and oil. It is useful for manufacturer and utilities to evaluate the insulation design, temperature distribution and loss of insulation life.
Denis Aubry - One of the best experts on this subject based on the ideXlab platform.
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parameter identification of nonlinear time dependent rubber Bushings models towards their integration in multibody simulations of a vehicle chassis
Mechanical Systems and Signal Processing, 2013Co-Authors: Guillaume Puel, Beatrice Bourgeteau, Denis AubryAbstract:Abstract Rubber Bushings are extensively used linking parts in a vehicle chassis that allow to filter noise and vibration. They influence much, however, the transient behavior of the vehicle, such as its steering performance. Therefore, building a multibody simulation with a relevant description of the rubber Bushings is useful to describe the significant characteristics of the vehicle's steering behavior. First, a nonlinear time-dependent model describing a rubber bushing's mechanical behavior is presented. In order to be relevant, the parameters associated with this model are then identified from experimental tests using an adjoint state formulation of the identification problem. The identified values are eventually validated using additional experimental data.
