The construction of the future energy structure of China under the 2050 carbon-neutral vision requires compact direct current(DC)gas-insulation equipment as important nodes and solutions to support electric power tran...The construction of the future energy structure of China under the 2050 carbon-neutral vision requires compact direct current(DC)gas-insulation equipment as important nodes and solutions to support electric power transmission and distribution of long-distance and large-capacity.This paper reviews China's 10-year progress in DC gas-insulated equipment.Important progresses in basic research and industry perspective are presented,with related scientific issues and technical bottlenecks being discussed.The progress in DC gas-insulated equipment worldwide(Europe,Japan,America)is also reported briefly.展开更多
The requirements for the construction of a new power system inevitably pose significant challenges and changes to the operation and maintenance of the power grid.To ensure the safe and stable operation of ultra-high v...The requirements for the construction of a new power system inevitably pose significant challenges and changes to the operation and maintenance of the power grid.To ensure the safe and stable operation of ultra-high voltage(UHV)transmission equipment,this work reports on the principles and preliminary results of using electroluminescence(EL)-based photon counting(PC)methods for early detection of micro-defects in GIS/GIL insulation spacer.In this study,the impact of voltage,gas pressure,and gas composition on the photon response of insulation is examined.Furthermore,the corresponding relationship between defect status and photon response characteristics is explored,along with the discussion of the EL mechanism and its evolution induced by defects.The research results demonstrate that PC measurement exhibits high sensitivity to variations in millimeter-scale defect size,position,and morphology at lower electric fields before partial discharge(PD)initiation.With this regard,this paper reveals promising prospects for the early detection of micro-defects in UHV transmission equipment using PC measurement-based methods.展开更多
Partial discharge(PD)detection is considered one of the most crucial and effective methods for identifying defects in electrical equipment.Consequently,investigating advanced and efficient PD monitoring techniques is ...Partial discharge(PD)detection is considered one of the most crucial and effective methods for identifying defects in electrical equipment.Consequently,investigating advanced and efficient PD monitoring techniques is essential for the development of gas-insulated equipment(GIE)and the construction of ultra-high-voltage(UHV)networks.This paper first explores the causes and impact characteristics of various defects in GIE based on experimental results and simulation analysis.It then reviews current research on advanced PD measurement techniques,integrating acoustic,chemical and optical methods.The findings preliminarily demonstrate the unique advantages and applicability of the advanced methods for complex detection environments.Finally,this paper ad-dresses the technical challenges and potential breakthroughs associated with these detection techniques.In this regard,this study aims to provide technical insights and research directions for defect detection techniques in UHV GIE.展开更多
Polypropylene(PP)emerges as a promising power cable insulation material,with its electrothermal performance fundamentally determining application potential and operational durability.Meanwhile,antioxidants,renowned fo...Polypropylene(PP)emerges as a promising power cable insulation material,with its electrothermal performance fundamentally determining application potential and operational durability.Meanwhile,antioxidants,renowned for their ability to enhancing thermal stability and insulating performance of polyolefins,offer a viable strategy for optimizing PP.Thus,this study establishes molecular dynamics models for PP/antioxidant systems with antioxidant type as a variable,to investigate the microstructural evolution and electrothermal properties of antioxidant-modified PP across different temperatures.The simulation results indicate that compared to PP neat system,PP/AO736 system shows a 26K increase in glass transition temperature,a 13.88%reduction in relative dielectric constant,and a 37.6%enhancement in breakdown strength at 400 K.Besides,PP/HP system demonstrates advantages in regulating heat transfer,with a 33.1%improvement in thermal conductivity at 300 K.These findings provide methodological guidance for improving the electrical and thermal properties of PP.展开更多
To suppress the charge accumulation on the spacer surface in direct current(DC)gas insulated transmission line(GIL)is an important and emergent issue for the development of a clean,safe and economic smart grid.A desig...To suppress the charge accumulation on the spacer surface in direct current(DC)gas insulated transmission line(GIL)is an important and emergent issue for the development of a clean,safe and economic smart grid.A design method of the DC spacer is proposed,and a spacer prototype is prepared and evaluated both by simulation and type test.The DC withstand voltage test and polarity reversal test are performed using the new DC spacer compared with a commercialised 220 kVAC spacer.The simulation results indicate that the surface electric field and surface charge of the DC spacer are lower than those of the alternating current(AC)spacer under DC voltage.The test results verify that the surface flashover voltage of this DC spacer is higher than that of the AC spacer.The potential feasibility of the spacer design for HVDC is discussed.It is hoped that the content of this paper can bring new ideas in the development of HVDC gas insulated equipment.展开更多
The 2050 carbon-neutral vision spawns a novel energy structure revolution,and the construction of the future energy structure is based on equipment innovation.Insulating material,as the core of electrical power equipm...The 2050 carbon-neutral vision spawns a novel energy structure revolution,and the construction of the future energy structure is based on equipment innovation.Insulating material,as the core of electrical power equipment and electrified transportation asset,faces unprecedented challenges and opportunities.The goal of carbon neutral and the urgent need for innovation in electric power equipment and electrification assets are first discussed.The engineering challenges constrained by the insulation system in future electric power equipment/devices and electrified transportation assets are investigated.Insulating materials,including intelligent insulating material,high thermal conductivity insulating material,high energy storage density insulating material,extreme environment resistant insulating material,and environmental-friendly insulating material,are cat-egorised with their scientific issues,opportunities and challenges under the goal of carbon neutrality being discussed.In the context of carbon neutrality,not only improves the understanding of the insulation problems from a macro level,that is,electrical power equipment and electrified transportation asset,but also offers opportunities,remaining issues and challenges from the insulating material level.It is hoped that this paper en-visions the challenges regarding design and reliability of insulations in electrical equipment and electric vehicles in the context of policies towards carbon neutrality rules.The authors also hope that this paper can be helpful in future development and research of novel insulating materials,which promote the realisation of the carbon-neutral vision.展开更多
An insulator surface charge may be responsible for flashover along the insulator surface.In this study,experimental investigations of post insulator surface charge are performed using a variety of voltage,gas type,and...An insulator surface charge may be responsible for flashover along the insulator surface.In this study,experimental investigations of post insulator surface charge are performed using a variety of voltage,gas type,and gas pressure conditions.Combining the model of surface charge transport,the dominant charge transition is revealed considering gas partial discharge.The results show that hetero‐polar charge accumulates near the high voltage electrodes on the insulator at one atmospheric pressure with an applied DC voltage ranging from-10 to-60 kV.The area ratio of the hetero‐polar charge increases from 23%to 53%.It also generates a reversed polarity of surface charges.Under-20 kV,the surface charge near the grounded electrode gradually becomes homo‐polar charges with the decrease of SF6 in 0.5 MPa SF6/N2 gas mixtures.In this case,the most dominant pathway for charge accumulation is through the insulation gas rather than the insulator.For the 20%SF6/80%N2 gas mixtures,homo‐polar charge speckles appear near the grounded plate electrode when the pressure of SF6/N2 gas mixtures decreases to 0.1 MPa.This means that the partial discharge occurs in gas side under a lower gas pressure.Refer to the presenting findings,the dominant charge transition on post in-sulators is provided as an important reference.展开更多
基金supported by the State Key Laboratory of Power System and Generation Equipment,Dept.of Electrical Engineering,Tsinghua University(Grant No.SKLD22M03)Taikai Innovation Funding(Grant No.JTCB202209210002).
文摘The construction of the future energy structure of China under the 2050 carbon-neutral vision requires compact direct current(DC)gas-insulation equipment as important nodes and solutions to support electric power transmission and distribution of long-distance and large-capacity.This paper reviews China's 10-year progress in DC gas-insulated equipment.Important progresses in basic research and industry perspective are presented,with related scientific issues and technical bottlenecks being discussed.The progress in DC gas-insulated equipment worldwide(Europe,Japan,America)is also reported briefly.
基金supported by the National Natural Science Foundation of China under Grant No.52125703.
文摘The requirements for the construction of a new power system inevitably pose significant challenges and changes to the operation and maintenance of the power grid.To ensure the safe and stable operation of ultra-high voltage(UHV)transmission equipment,this work reports on the principles and preliminary results of using electroluminescence(EL)-based photon counting(PC)methods for early detection of micro-defects in GIS/GIL insulation spacer.In this study,the impact of voltage,gas pressure,and gas composition on the photon response of insulation is examined.Furthermore,the corresponding relationship between defect status and photon response characteristics is explored,along with the discussion of the EL mechanism and its evolution induced by defects.The research results demonstrate that PC measurement exhibits high sensitivity to variations in millimeter-scale defect size,position,and morphology at lower electric fields before partial discharge(PD)initiation.With this regard,this paper reveals promising prospects for the early detection of micro-defects in UHV transmission equipment using PC measurement-based methods.
基金Natural Science Foundation of Beijing,Grant/Award Number:3244048National Natural Science Foundation of China,Grant/Award Number:52407175‘Chen Guang’project supported by the Shanghai Municipal Education Commission and the Shanghai Education Development Foundation,Grant/Award Number:21CGA63。
文摘Partial discharge(PD)detection is considered one of the most crucial and effective methods for identifying defects in electrical equipment.Consequently,investigating advanced and efficient PD monitoring techniques is essential for the development of gas-insulated equipment(GIE)and the construction of ultra-high-voltage(UHV)networks.This paper first explores the causes and impact characteristics of various defects in GIE based on experimental results and simulation analysis.It then reviews current research on advanced PD measurement techniques,integrating acoustic,chemical and optical methods.The findings preliminarily demonstrate the unique advantages and applicability of the advanced methods for complex detection environments.Finally,this paper ad-dresses the technical challenges and potential breakthroughs associated with these detection techniques.In this regard,this study aims to provide technical insights and research directions for defect detection techniques in UHV GIE.
基金supported by the National Natural Science Foundation of China(No.52307157)Project supported by the Natural Science Foundation of Hunan Province,China(No.2025JJ90178).
文摘Polypropylene(PP)emerges as a promising power cable insulation material,with its electrothermal performance fundamentally determining application potential and operational durability.Meanwhile,antioxidants,renowned for their ability to enhancing thermal stability and insulating performance of polyolefins,offer a viable strategy for optimizing PP.Thus,this study establishes molecular dynamics models for PP/antioxidant systems with antioxidant type as a variable,to investigate the microstructural evolution and electrothermal properties of antioxidant-modified PP across different temperatures.The simulation results indicate that compared to PP neat system,PP/AO736 system shows a 26K increase in glass transition temperature,a 13.88%reduction in relative dielectric constant,and a 37.6%enhancement in breakdown strength at 400 K.Besides,PP/HP system demonstrates advantages in regulating heat transfer,with a 33.1%improvement in thermal conductivity at 300 K.These findings provide methodological guidance for improving the electrical and thermal properties of PP.
基金The National Key R&D Program of China,Grant/Award Number:2018YFE0200100The National Natural Science Foundation of China,Grant/Award Number:51921005。
文摘To suppress the charge accumulation on the spacer surface in direct current(DC)gas insulated transmission line(GIL)is an important and emergent issue for the development of a clean,safe and economic smart grid.A design method of the DC spacer is proposed,and a spacer prototype is prepared and evaluated both by simulation and type test.The DC withstand voltage test and polarity reversal test are performed using the new DC spacer compared with a commercialised 220 kVAC spacer.The simulation results indicate that the surface electric field and surface charge of the DC spacer are lower than those of the alternating current(AC)spacer under DC voltage.The test results verify that the surface flashover voltage of this DC spacer is higher than that of the AC spacer.The potential feasibility of the spacer design for HVDC is discussed.It is hoped that the content of this paper can bring new ideas in the development of HVDC gas insulated equipment.
文摘The 2050 carbon-neutral vision spawns a novel energy structure revolution,and the construction of the future energy structure is based on equipment innovation.Insulating material,as the core of electrical power equipment and electrified transportation asset,faces unprecedented challenges and opportunities.The goal of carbon neutral and the urgent need for innovation in electric power equipment and electrification assets are first discussed.The engineering challenges constrained by the insulation system in future electric power equipment/devices and electrified transportation assets are investigated.Insulating materials,including intelligent insulating material,high thermal conductivity insulating material,high energy storage density insulating material,extreme environment resistant insulating material,and environmental-friendly insulating material,are cat-egorised with their scientific issues,opportunities and challenges under the goal of carbon neutrality being discussed.In the context of carbon neutrality,not only improves the understanding of the insulation problems from a macro level,that is,electrical power equipment and electrified transportation asset,but also offers opportunities,remaining issues and challenges from the insulating material level.It is hoped that this paper en-visions the challenges regarding design and reliability of insulations in electrical equipment and electric vehicles in the context of policies towards carbon neutrality rules.The authors also hope that this paper can be helpful in future development and research of novel insulating materials,which promote the realisation of the carbon-neutral vision.
基金supported by the National Natural Science Foundation of China,Grant Numbers:52237007 and 51977063Natural Science Foundation of Hunan Province,Grant Number:2022JJ20010.
文摘An insulator surface charge may be responsible for flashover along the insulator surface.In this study,experimental investigations of post insulator surface charge are performed using a variety of voltage,gas type,and gas pressure conditions.Combining the model of surface charge transport,the dominant charge transition is revealed considering gas partial discharge.The results show that hetero‐polar charge accumulates near the high voltage electrodes on the insulator at one atmospheric pressure with an applied DC voltage ranging from-10 to-60 kV.The area ratio of the hetero‐polar charge increases from 23%to 53%.It also generates a reversed polarity of surface charges.Under-20 kV,the surface charge near the grounded electrode gradually becomes homo‐polar charges with the decrease of SF6 in 0.5 MPa SF6/N2 gas mixtures.In this case,the most dominant pathway for charge accumulation is through the insulation gas rather than the insulator.For the 20%SF6/80%N2 gas mixtures,homo‐polar charge speckles appear near the grounded plate electrode when the pressure of SF6/N2 gas mixtures decreases to 0.1 MPa.This means that the partial discharge occurs in gas side under a lower gas pressure.Refer to the presenting findings,the dominant charge transition on post in-sulators is provided as an important reference.
