The Three Gorges hydropower station, namely the Three Gorges water control project, is also called the Three Gorges project. The Xiling gorge section of the Yangtze River and the Gezhouba Dam hydropower station in the lower reaches of Yichang, Hubei, China constitute a cascade hydropower station. The Three Gorges hydropower station is the largest hydropower station in the world and the largest construction project ever built in china. The migration, the environment and many other problems caused by it make it from the beginning of the establishment of the moment, it has always been accompanied by huge controversy. There are more than 10 functions of the Three Gorges Hydropower Station: shipping, power generation, planting and so on. The Three Gorges Hydropower Station was approved by the National People's Congress of China in 1992 and started construction in 1994. The water power generation was completed in the afternoon of June 2003 and completed in 2009. The 1 unit mainly by the German company Voith (VOITH), General Electric (GE) company, SIEMENS (SIEMENS) Company VGS joint venture and Alston French (ALSTOM) ALSTOM joint venture company, Swiss company ABB which provides. In signing the supply agreement, they have promised to transfer the relevant technology free of charge to the motor manufacturing enterprises in china. The power transmission and transformation system of the Three Gorges hydropower station is under construction and management by the state Power Grid Corp of China. It is expected that a total of 15 500 thousand volt high voltage transmission lines will be installed and connected to all regional power grids. The dam of the Three Gorges dam is 185 meters high, the water storage level is 175 meters, and the reservoir is 2335 meters long. The total investment is 95 billion 460 million yuan RMB, and 32 hydropower units with a single capacity of 700 thousand KW are installed. The Three Gorges power station last one hydro unit, put into operation in July 4, 2012, which means that the Three Gorges hydropower station installed capacity reached 22 million 400 thousand kilowatts in July 4, 2012, has become the world's largest hydroelectric station and clean energy production base.