With the development of deep-sea wind power and large-scale onshore clean energy,the global demand for higher voltage level DC cable power transmission technology has become increasingly urgent.This paper systematical...With the development of deep-sea wind power and large-scale onshore clean energy,the global demand for higher voltage level DC cable power transmission technology has become increasingly urgent.This paper systematically reviews the technical advancements in high voltage direct current(HVDC)cable accessories,addressing design challenges of terminations and joints,insulation material performance,manufacturing processes for large-scale components,standard frameworks and long-term reliability.The core challenges in HVDC accessories are identified as conductivity matching of insulating materials,interface electric field regulation and multi-field coupling reliability,requiring synergistic optimisation of electrical,thermal and mechanical behaviours through the modification of rubber materials,interfacial compatibility and multi-physics field modelling.Silicon rubber and ethylene propylene diene monomer made in China have achieved electrical properties comparable to international standards,yet breakthroughs in tear resistance,process consistency and environmental sustainability remain critical.The injection moulding defect control and uniform moulding process of large rubber and epoxy parts demand further improvement.The standard system in China needs to be strengthened in terms of systematic certification and long-term reliability evaluation.Future research should prioritise eco-friendly material development,intelligent monitoring technologies and multi-field coupling ageing life prediction to enhance the reliability of HVDC cable systems under extreme voltages and complex operational scenarios.展开更多
Silicone rubber(SR)is extensively used as insulation for cable accessories,directly affecting their design and operation.The distinctive feature of cable accessory insulation,operating under mechanical stretching,has ...Silicone rubber(SR)is extensively used as insulation for cable accessories,directly affecting their design and operation.The distinctive feature of cable accessory insulation,operating under mechanical stretching,has not received sufficient attention in relevant standards and research.This study investigates two essential electrical parameters of SR insulation:relative permittivity and AC breakdown strength,analysing and summarising their variations during mechanical stretching.By comparing the parameter variations of SR samples with different filler contents and matrix compositions,the microscopic stretching behaviour and performance change mechanisms under mechanical stretching are explored.The results reveal the tensile effect on SR insulation,demonstrating that as the stretching ratio increases,the relative permittivity decreases,whereas the AC breakdown strength shows an increasing trend.Increasing filler content and incorporating low molecular weight components suppress the tensile effect,whereas decreasing filler content has the opposite effect.Given the significant correlation between these two parameters,the orientation and elongation of molecular chains are considered the primary factors influencing the tensile effect on SR insulation.This insight proposes a novel approach to control and optimise the performance of cable accessory insulation.展开更多
The worldwide increasing demand for electricity,coupled with the need for more reliable infrastructures and more interconnected networks,has put forward high voltage direct current(HVDC)technologies for energy transmi...The worldwide increasing demand for electricity,coupled with the need for more reliable infrastructures and more interconnected networks,has put forward high voltage direct current(HVDC)technologies for energy transmissions.Questions still arise as regards synthetic insulation for cable systems and accessories,as it remains one of the weak points in energy transmission lines.The field distribution in such systems intimately depends upon the electrical conductivity,being temperature and field dependent,and upon the cable/accessory geometry,that is its design.Optimising the design equates to homogenising as much as possible the electric field,particularly the tangential field at the interface between dielectrics,and avoiding field hot spots.Different designs for cable accessory are conceivable that do not necessarily involve the interposition of a field grading layer between the cable insulation and the joint body.In this work,we explore different evolutions of the design,spanning from geometry refinement to setting a two-layers joint body.The idea of keeping the same polymer and using fillers to impart nonlinearity to the conductivity is put forward.Results show that significant reduction of field maxima can be reached with this design.The so-constructed fictive material appears feasible considering literature data.Whether full objects can be produced is an open question.展开更多
基金supported by the Science and Technology Project of SGCC(521001250033-246-YYGG).
文摘With the development of deep-sea wind power and large-scale onshore clean energy,the global demand for higher voltage level DC cable power transmission technology has become increasingly urgent.This paper systematically reviews the technical advancements in high voltage direct current(HVDC)cable accessories,addressing design challenges of terminations and joints,insulation material performance,manufacturing processes for large-scale components,standard frameworks and long-term reliability.The core challenges in HVDC accessories are identified as conductivity matching of insulating materials,interface electric field regulation and multi-field coupling reliability,requiring synergistic optimisation of electrical,thermal and mechanical behaviours through the modification of rubber materials,interfacial compatibility and multi-physics field modelling.Silicon rubber and ethylene propylene diene monomer made in China have achieved electrical properties comparable to international standards,yet breakthroughs in tear resistance,process consistency and environmental sustainability remain critical.The injection moulding defect control and uniform moulding process of large rubber and epoxy parts demand further improvement.The standard system in China needs to be strengthened in terms of systematic certification and long-term reliability evaluation.Future research should prioritise eco-friendly material development,intelligent monitoring technologies and multi-field coupling ageing life prediction to enhance the reliability of HVDC cable systems under extreme voltages and complex operational scenarios.
基金National Natural Science Foundation of China,Grant/Award Numbers:52177021,92266110Research Initiation Project at Fuzhou University,Grant/Award Number:511507.
文摘Silicone rubber(SR)is extensively used as insulation for cable accessories,directly affecting their design and operation.The distinctive feature of cable accessory insulation,operating under mechanical stretching,has not received sufficient attention in relevant standards and research.This study investigates two essential electrical parameters of SR insulation:relative permittivity and AC breakdown strength,analysing and summarising their variations during mechanical stretching.By comparing the parameter variations of SR samples with different filler contents and matrix compositions,the microscopic stretching behaviour and performance change mechanisms under mechanical stretching are explored.The results reveal the tensile effect on SR insulation,demonstrating that as the stretching ratio increases,the relative permittivity decreases,whereas the AC breakdown strength shows an increasing trend.Increasing filler content and incorporating low molecular weight components suppress the tensile effect,whereas decreasing filler content has the opposite effect.Given the significant correlation between these two parameters,the orientation and elongation of molecular chains are considered the primary factors influencing the tensile effect on SR insulation.This insight proposes a novel approach to control and optimise the performance of cable accessory insulation.
文摘The worldwide increasing demand for electricity,coupled with the need for more reliable infrastructures and more interconnected networks,has put forward high voltage direct current(HVDC)technologies for energy transmissions.Questions still arise as regards synthetic insulation for cable systems and accessories,as it remains one of the weak points in energy transmission lines.The field distribution in such systems intimately depends upon the electrical conductivity,being temperature and field dependent,and upon the cable/accessory geometry,that is its design.Optimising the design equates to homogenising as much as possible the electric field,particularly the tangential field at the interface between dielectrics,and avoiding field hot spots.Different designs for cable accessory are conceivable that do not necessarily involve the interposition of a field grading layer between the cable insulation and the joint body.In this work,we explore different evolutions of the design,spanning from geometry refinement to setting a two-layers joint body.The idea of keeping the same polymer and using fillers to impart nonlinearity to the conductivity is put forward.Results show that significant reduction of field maxima can be reached with this design.The so-constructed fictive material appears feasible considering literature data.Whether full objects can be produced is an open question.
