ABB group is one of the top 500 companies in the world, with its headquarters in Zurich, Switzerland. ABB was formed in 1988 by the merger of two international companies with a history of more than 100 years, asea of Sweden and brown Boveri of Switzerland. The two companies were founded in 1883 and 1891 respectively. ABB (www.abb. Com) is a leading manufacturer in the field of power and automation technology. ABB's technology can help power, utility and industrial customers improve their performance while reducing the adverse impact on the environment. ABB Group operates in more than 100 countries with 124000 employees, with sales of US $32 billion in 2010. ABB invented and created many products and systems, including the world's first three-phase transmission system, the world's first self cooling transformer, HVDC technology and the first industrial robot, and took the lead in their commercial application. ABB has a wide range of product lines, including a full range of power transformers