Study On Insulation Of 10kV Three-phase Concentric High-Temperature Superconducting Cable

High temperature superconducting cable has been widely researched among countries worldwide and is promising to be the power electricity transmission line for next generation with its advantages in large transmission current,compact structure and low losses.In order to require a superconducting cable which is long-term stable,safe and reliably operable,the research over the cable insulation is necessary.The project AmpaCity project established by Nexans,RWE Deutschland from France and the Karlsruhe Institute of Technology(KIT)from Germany was started since September,2011.The aim for the project is to produce a three-phase concentric CD high temperature superconducting cable.The superconducting layer of the cable under this structure is mainly applied with the low temperature insulation material of PPLP to conduct the insulation by sharing the same set of low temperature container without superconducting shielding layer,which can save the superconducting material.The high temperature superconducting cable under this structure can also be applied in the power transmission under middle and low voltage.This paper optimizes the insulation design for lOkV three-phase concentric high temperature superconducting cables,the main work is as follows:The experimental schemes of low temperature insulation characteristics of insulating materials PPLP and Kraft paper are presented,then the AC current puncturing test and the lighting impulse test of cable samples are conducted.Combination with the weibull distribution,the insulation strength of insulating paper is analyzed,and the breakdown field strength values corresponding to 0.1%breakdown probability are obtained.Aiming at the insulation characteristics of insulating materials,the main insulation thickness of lOkV three-phase concentric high temperature superconducting cable is developed and analyzed by numerical simulation.Based on the design principle of stress cone of conventional cable terminal,the dimension calculation of stress cone of insulating material is carried out,and the electric field distribution of stress cones with different shapes is analyzed by simulation software.Research on the conductor layer of 10kV three-phase concentric high temperature superconducting cable mainly focues on the number of layers of the conductor layer and the total root number of the tapes.According to the minimum voltage loss and current sharing,the design software of conductor layer is written,and the design results of 10kV three-phase concentric high temperature superconducting cable are given.