Investigation on characteristics of 275 kV XLPE cable removed from actual service line

Abstract

Construction o f the Removed Cable XLPE cables have been increasingly employed for the actual lines, replacing oil-filled cables. In the extra high voltage field, more than ten years have passed since the first installed 275kV XLPE cable in Japan. Recently, technical requirements for a diagnostic method t o actual service lines have been increasing. A lot of available informations on the method were expected to be gathered by the investigation about actually used 275kV XLPE cables. The Tokyo Electric Power Co., Inc. and Fujikura Ltd. conducted various electrical tests and physical tests on the first 275kV XLPE cable by removing from the actual service line t o check its insulation performance and the state of deterioration in physical properties of the cable materials. The cable investigated was manufactured by dry curing method and constructed with a corrugated aluminium sheath, which means no water will penetrate into cable. No serious deterioration was observed for the removed 275kV XLPE cable.