Cable Accessory Technologies – Current Situation and Developments to Watch by Klaus-Dieter Haim
Along with the expected future energy transition toward increased importance of electricity will be a significant change in the contribution of low and medium voltage networks to smart grids. With this, the ratio of cables compared to overhead lines at these voltage levels will increase and, in fact, in some countries has already reached 100 percent. In the case of high and extra high voltages, although overhead lines will remain the dominant means of power transmission, the relative important of cables will increase as well. In terms of technology, polymeric cables have now become a cost effective and extremely reliable solution for all AC applications and voltages as well as for most DC cable applications. With this, the main cause of cable system failures these days is either mechanical damage by third parties or poor workmanship during installation of accessories. In this regard, responsibility for errors during installation is not due only to workers installing joints. Rather, manufacturers of accessories can also influence failure rates through use of quality materials as well as application of fault tolerant installation methods. This presentation reviews alternative installation technologies and different insulation materials, from the low to the extra high voltages. The focus is on accessory insulation and also on connection of conductor and cable screen as well as on outer protection against both moisture and mechanical damage.