XLPE and EPM are also the best in terms of electrical properties. PVC mesothelial loss is too high, not suitable for high voltage system, PVC thermal resistance is also high, affecting cable cooling.

As a cable insulation and heat shrink tube material, the current use of a relatively wide range of materials are cross-chain polyethylene and ethyl propylene glue, especially cross-chain polyethylene has the most promising development. PVC insulation, currently in use in 1~6 kV power cables and other low voltage wires. Due to the poor thermal and electrical performance of PVC, under the same load flow, compared with XLPE, the conductive core section of PVC insulated power cable must be increased. For example, in 1 kV power cable, the conductive core cross-section should be increased by 15%-20%, and for 6 kV to increase by 20% to 30%. It can be expected that, in addition to special occasions such as low-voltage flame retardant, PVC insulated power cables will always be replaced by XLPE insulated power cables in the future. XlPE power cables can save 20% to 30% more in manufacturing costs compared to several other commonpower cables when the same power is delivered. In the modern production of power cablein in our country, we must give it to be actively promoted.

At present, various other polymer insulation materials such as thermal elastic adhesive (TPE) are more expensive, while fluoroplastics (PTFE) and silicone rubber (MQ) can only be used when high temperature insulation is required. This article mainly introduces the design and production of XLPE power cable.

Ethylene-propylene insulated cable has been widely used in special action cables such as fire resistance, flame retardant and atomic radiation. Ethylene-propylene insulation is also often used for 35k V across the river, across the sea and other large-length underwater cables. It has better softness and water tree protection characteristics than XLPE cables.

PVC cable flame retardant is good, in 1kV below the low voltage cable, multi-core control cable and indoor wiring and other aspects are widely used.

At present, more than 500kV ultra-high voltage polymer insulation power cable is being developed, 275kV and below XLPE insulation power cable has been put into the market.

XLPE绝缘材料的物理性能

从电热特性看, XLPE及EPM也是最优越的。PVC介损太高，不宜用于高电压系统，PVC的热阻也高，影响电缆散热。

作为电缆绝缘和热缩管的材料，当前用得比较广的材料有交链聚乙烯和乙丙胶，尤其是交链聚乙烯最有发展前途。PVC绝缘，当前在1一6 kV电力电缆及其他低压电线中还在使用。由于PVC热电性能差，在相同载流量下，与XLPE相比，PVC绝缘电力电缆的导电芯截面必须增大。如用于1 kV电力电缆中，导电芯截面要增大15%-20%，用于6 kV时则要增大20%~30%。可以预料，除用于低压阻燃等特殊场合外，PVC绝缘电力电缆将来总要被XLPE绝缘电力电缆所代替。输送同样电能情况下，XLPE电力电缆的制造成本比其他几种常用电力电缆可节约20%-30%。在我国电力电缆现代化生产中，必须给以积极推广。

当前其他各种聚合物绝缘材料如热弹性胶(TPE)的价格较高，而氟塑料(PTFE)及硅橡胶(MQ)只有要求耐高温绝缘时才可以采用。本篇主要介绍XLPE电力电缆的设计及生产情况。

乙丙胶绝缘电缆在耐火、阻燃和耐原子能辐照等特殊作用电缆中得到了广泛应用。乙丙胶绝缘也经常用于35k V的过江、跨海等大长度水下电缆。它比XLPE电缆有较好的柔软性及水树防止特性。

PVC电缆阻燃性较好，在1kV以下的低压电缆、多芯控制电缆及室内布线等方面还被广泛采用。

当前500kV以上的超高压聚合物绝缘电力电缆正在研制之中，275kV及以下的XLPE绝缘电力电缆己投入市场。