Just as composite insulators have already established major inroads as housings for equipment such as station class surge arresters and instrument transformers, they are now also increasingly being specified for HV cable sealing ends, especially for applications near populated areas. This shift in technology has already become apparent at voltages up to 230 kV and a similar transition at 345 kV now seems on the horizon.
INMR visits Taihan Electric Wire – a Korean based manufacturer of cables as well as cable accessories – where such a changeover is already in progress.
Taihan Electric Wire (Taihan) has been producing cable accessories since 1985 and, according to Kim Hyun Joo, Head of the company’s new Dangjin plant, has witnessed a shift in technologies in a number of areas. For example, EHV cables up to 500 kV have shifted decisively away from oil-filled in favor of XLPE, while cable accessories such as joints have moved increasingly toward pre-molded types.
Kim also reports that today nearly twothirds of all cable terminations being produced at Taihan are composite- housed. This, he explains, is due to new injection molding equipment that allows the company to make its own composite housings up to 550kV but is also a reflection of a growing customer preference.
“Composite terminations instead of porcelain,” explains Kim, “offer a number of advantages for users including lower price, increased safety, less environmental risk and faster installation. For example, depending on voltage class, the time needed to install silicone-housed terminations can be as much as 20 percent less than for traditional porcelain.”
Indeed, more rapid installation has also become a key factor driving development of pre-molded joints (PMJs). These are increasingly replacing pre-fabricated joints since they offer a built-in compressive force that eliminates the need for such apparatus on site. Says Kim, “technology has clearly shifted in this direction since there are fewer parts and no need for a compression ring. This makes them less costly to produce and quicker to install.” He notes that within two years Taihan plans to offer PMJs even up to 500 kV.
Kim Han Hwa, Head of the Engineering Team, takes INMR on a visit through the plant that specializes in supplying cable accessories for both oil and XLPE cables, including splices and terminations. It also produces a range of custom-made epoxy insulation components, such as GIS spacers.