American Superconductor and China’s IEE Demo HTS Transformer

March 08, 2006 by Jeff Shepard

American Superconductor Corp. and China's Institute of Electrical Engineering (IEE) jointly announced that IEE has successfully demonstrated a prototype superconductor-based power transformer for the first time in a power grid in China. The transformer was fabricated by IEE in collaboration with TBEA Industrial Transformer Group, the largest transformer manufacturer in China, utilizing high temperature superconductor (HTS) wire manufactured by AMSC.

The HTS transformer has operated since November 21, 2005 in a power grid in the city of Changji, Xinjiang Province serving a TBEA manufacturing plant. The superconductor transformer developed by IEE is a three-phase, 630kVA device that transforms voltages from 10kV to 400V. It utilizes an amorphous alloy core to further reduce electrical losses over that achieved by the superconductor wires alone. The total energy efficiency of this first device was 98.3%.

Replacing copper wire currently employed in conventional transformers with high efficiency HTS wire reduces the waste of energy inside the transformer due to copper wire's electrical resistance. Another major advantage is the substitution of cheap, environmentally-friendly liquid nitrogen (air is 79% nitrogen) in HTS transformers to provide cooling and electrical insulation for the more expensive electrical insulating oils utilized in conventional transformers. This reduces oil consumption and the risk of transformer fires associated with oil leaks.

According to Dr. Liye Xiao, Deputy Director of the IEE and Director of the Applied Superconductivity Laboratory at the Chinese Academy of Science, this project is an important step in demonstrating the value of superconductor transformers to improve the energy efficiency and reliability of power grids while reducing the amount of oil needed for use as the electrical insulation medium in large, conventional transformers. "Demand for electric power in China continues to grow dramatically year-over-year," said Dr. Xiao. "We need to utilize innovative technologies such as superconductor transformers, fault current limiters and other devices, to guarantee the reliability and stability of our power grids because electricity is an essential ingredient in achieving sustainable economic growth."

"This demonstration project is a critical step on the path to the development of practical, commercial superconductor transformers in China -- a market we believe will be very large," said Greg Yurek, chief executive of AMSC. "China represents one of the fastest growing markets for superconductor transformers. This is because the demand for electricity continues to rise very rapidly and because energy efficiency is becoming increasingly important in China."