P-Laser: Breakthrough in power cable systems

Abstract

New thermoplastic insulating compounds, High Performance Thermoplastic Elastomer (HPTE), were developed in Prysmian and represent a breakthrough in the field of MV and HV power cables. These materials gather good electrical and thermomechanical properties, comparable or even superior to those of XLPE, and are flexible and soft even though polypropylene based. The physico-chemical properties of HPTE can be tuned by changing crystallinity and other physico-chemical properties, tailoring the material for specific applications. HPTE is a proprietary special compound designed and developed within Milan central R&D laboratories as a result of several years of investigations. In spite of numerous and unsuccessful attempts that were made in the past for using polypropylene as insulation for medium and high voltage cables, it was now possible to develop a material that gathers the advantages of thermoplasticity and thermomechanical performances of a crosslinked polyethylene. HPTE insulation is characterized by tensile strength of 30-35 MPa, elongation at break of 700-800%, modulus of elasticity of 200-300 MPa, thermopressure at 130°C of 95%. This compound is therefore flexible and, at the same time, its crystallinity guarantees thermomechanical properties at temperature useful for medium and high voltage cable applications. HPTE is an innovative insulating material that does not require degassing treatments, does not suffer of amber generation and can be filtered at high level without degradative phenomena. Besides that it is recyclable and it does not emit methane or other by-products during manufacturing. HPTE insulating compound, together with thermoplastic semiconductive materials that were specifically developed for this application, are the key point of P-Laser technology, the very innovative process for the production of medium voltage cables. Due to the lack of degassing treatments it is in fact possible to produce the complete cable in one step process, starting from the conductor and giving in one shot the finished cable. At present R&D efforts are going on with the aim of developing HV cables based on this innovative insulating material that will offer important advantages with respect to the current technology for both AC and DC applications.