Ken Yatsuka

Nonlinear transient analysis of electric field coupled with temperature at the joint of a power cable

Distribution of temperature and electric field at the joint of a dc power cable is analyzed taking into account the nonlinearity of electric resistance which is a function of temperature and electric field strength. >

Development of failure prediction method for accessories of XLPE cable lines

Since dielectric breakdown failures have sometimes occurred in XLPE (cross-linked polyethylene) cable facilities, the development of a failure prediction method is strongly desirable so that such failures during power transmission can be prevented in advance. As a result of failure analysis of 77 kV class XLPE cables, it has been found that most of such dielectric breakdowns in power transmission lines have occurred in the accessories, caused by defective execution. The authors have succeeded in developing a method to detect partial discharge occurring before the accessories generate such dielectric breakdown. They describe this method, and report on a study to apply it to failure prediction technology. The authors constructed a line incorporating various types of accessories and evaluated the possibility of detecting such partial discharges to determine the practical feasibility of the proposed method. As a result, it was ascertained that one can detect a partial discharge in the case of every accessory investigated in the present study.<<ETX>>

Field Test of 3 phase, 22.9kV, 100m HTS Cable System in KEPCO

Starting from investigation of feasibility and basic studies, KEPCO/KEPRI has carried an enterprising project for HTS cable system since 2002. The objectives of this project are to demonstrate HTS cable system and evaluate the feasibility in electricity utilitys view. The installation of 100m/3phase/22.9kV/50MVA HTS cable system is undergoing in KEPCOs test yard, located in Gochang, Korea. The HTS cable system consists of 100m long cable, two terminations and a cooling system. To simulate the actual cable installation, the 55m section of the 100m long cable was installed into an underground tunnel. Commissioning test is scheduled at the end of September, 2005 and followed by long term operation test. In this paper, the installation of HTS cable system and initial results of system operation will be summarized