Transformer appeared as early as the end of the 19th century. With the development of electric power industry, the voltage level and accuracy level of transformers have been greatly improved, and many special transformers have also been developed, such as voltage and current composite transformers, DC current transformers, high accuracy current ratios and voltage ratios, high current laser current transformers, electronic circuit compensation transformers, photoelectric transformers in high voltage systems, and voltage Current transformer. In the power industry, in order to develop a power system of what voltage level and scale, it is necessary to develop transformers of corresponding voltage level and accuracy for the needs of power system measurement, protection and control.
According to the planning of the State Grid and China Southern Power Grid, during the "12th Five Year Plan" period, China's ultra-high voltage AC and DC investment was about 540 billion yuan, including 280 billion yuan of high-voltage AC and 220 billion yuan of DC. The national high-voltage AC power system will be built into a "three horizontal, three vertical and one ring network" pattern, and the construction goal of transmitting coal power, wind power and solar power from the north, northwest and northeast to the Bohai Rim and southeast regions, as well as hydropower from southwest to southeast regions, will be jointly completed through ultra-high voltage AC and DC.
The main equipment of UHV AC includes UHV transformer, reactor, GIS combined switch, transformer and other equipment. Zhu Qian, an analyst from the Prospective Industry Research Institute, pointed out that the equipment investment accounted for about 45% of the UHV investment, including transformer (including reactor) accounting for about 30% of the equipment investment, GIS accounting for about 25%, and mutual inductor accounting for about 10%. According to the estimation of UHV AC investment, the investment in transformers during the "Twelfth Five Year Plan" period is about 13 billion yuan.
