| Title |
A Evaluation Technique for Reliability of Extra-High Voltage Cable Accessories using High Frequency Partial Discharge Measurement |
| Authors |
신두성(Sin, Du-Seong) ; 이창영(Lee, Chang-Yeong) ; 김충식(Kim, Chung-Sik) ; 전승익(Jeon, Seung-Ik) ; 김동욱(Kim, Dong-Uk) ; 박완기(Park, Wan-Gi) |
| Keywords |
EHV cable accessory ; High frequency partial discharge (HFPD) ; Interface |
| Abstract |
In this paper, partial discharge (PD) measurement was performed to evaluate the quality of the cable joint and termination constructions. The resistive coupling technique for PD detection using resistivity of semiconducting layer of the cable in the accessories, such as joints and terminations. With high frequency PD (HEPD) measurement, an excellent sensitivity below 20pC could be achieved under unshielded condition. The localization of the defects in the accessories could be identified. During heating cycle, PDs were monitored and analyzed. At that time, the PDs were dependent on the temperature of the heating cycle and showed cyclic behaviors, which were attributed to local delamination of the interfaces, between epoxy unit and stress relief cone(SRC) and between SRC and cable, due to the difference of thermal expansion. As a conclusion, HFPD measurement technique was proven to be an effective diagnostic method for qualification of extra high voltage (EHV) cable accessories. With this technique, the optimal design of the components of the accessories could be verified not only in an early stage but also under operating condition. This technique would result in the improvement of the reliability of the EHV cable accessories. |