Aluminum composite conductors installed in China

3M's conductors are designed to increase transmission capacity without construction of new transmission lines.

The 3M Co. (St. Paul, Minn.) announced on July 28 that Chongqing Electric Power Corp. (Chongqing, China) has become the second major utility in the People's Republic of China to install the 3M Aluminum Conductor Composite Reinforced (3M ACCR) to boost transmission capacity on a key line without the need to build larger transmission towers. The utility says it needed extra capacity to meet anticipated heavy power demand for the summer Olympics in Beijing and did not have time to construct new towers.

This installation will serve more than a half-million residents within two districts in Chongqing City, an ancient city with a population of approximately 4 million, located on the Yangtze River in southwest China, within Sichuan Province.

In late 2007, Shanghai Electric became the first utility outside of the United States to install the 3M ACCR. Since then, utilities in Canada and Brazil also have chosen 3M's conductor to enlarge capacity on lines where new construction would pose economic or environmental problems. Fourteen utilities in the U.S. so far have deployed 3M ACCR, which can carry more than twice the power of conventional steel conductors of the same diameter.

3M ACCR's core is composed of aluminum oxide (alumina) fibers embedded in high-purity aluminum. The constituent materials are chemically compatible with each other and reportedly can withstand high temperatures without adverse chemical reactions or any appreciable loss in strength. The conductor also is highly resistant to corrosion and has the durability typically associated with all-aluminum conductors.

3M ACCR was developed with the support of the U.S. Department of Energy, which tested the conductor at Oak Ridge National Laboratory (ORNL, Oak Ridge, Tenn.), and with early contributions by the Defense Advanced Research Projects Agency.