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
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.
