|Recent Technologies and Aging Phenomena of Accessories for HV and EHV XLPE Cables|
|Investigation Committee on Technologies of Accessories for HV and EHV XLPE Cables|
|In Japan, XLPE cables that began to be applied in 1960's are widely used for transmission lines, and the circuit length of XLPE cable has already exceeded that of oil filled cables.
The certain trends are observed, towards "Smaller size" and "Easier assembly". For example, the pre-molded one piece type joint has been adopted for 66 and 154 kV class increasingly. For 275kV class, the pre fabricated type joint has been adopted in recent years.
Moreover, new type accessories designed with recent technologies have been developed and practically used, such as a polymeric insulator that consists of silicone rubber and a FRP tube in place of porcelain bushing.
On the other hand, in the circumstance such that the large number of the aged accessories will be over the design lifetime in near the future, the users have to manage the replacement and maintenance of these facilities.
Then, in order to enhance and make clear the recent trend and aging data of the accessories for XLPE cable, this committee has investigated them in a comprehensive and systematic manner.
This report is useful as a guide not only for the development of a new accessory in the future but also for efficient replacement and operation of the aged facilities.
The main contents are as follow:
1. Number of accessories and fault statistics
2. Type, construction and application of accessories in Japan and abroad
3. Design methods and properties of accessories
4. Aging phenomena of accessories and the diagnostic method
©2007. The Institute of Electrical Engineers of Japan