加铜罩对XLPE电缆绕组外端口特性的影响

交联聚乙烯(XLPE)电缆绕组变压器[1-5]在运行时,由于铁心和外防护罩的影响,使得电缆绕组电感值发生变化和外半导电层对地电容比试验空心绕组的外半导电层对地电容增大许多.因此了解铁心和外防护罩对电缆绕组外端口特性的影响是很有必要的.本文用加铜罩的方法模拟防护罩的作用的方法,对试验绕组进行了对比试验,并在前期研究[6]的基础上建立了考虑外半导电层对地电容影响电缆绕组外端口等效电路模型.为该种新型变压器的设计、保护及试验技术提供了依据.

Influence of brass mantle on transient input characteristic of XLPE cable windings

For an XLPE insulation cable transformer, due to the influence of the iron core and the outer tank, the inductance of the cable winding and the capacitance of outer semiconducting layers to ground will change, so it is important to study its influence on the transient input characteristic of this kind of transformer. In this paper, a brass mantle is added on the testing model to simulate the outer tank. On the basis of research results in [1], a transient input characteristic circuit model of cable windings is presented, in which the influence of the capacitance of outer semiconducting layers to ground is taken into account. It provides a theoretical basis for the design, protection and testing of this new type of power transformer.