The world’s first ±1100 kV UHV DC transmission project—Changji-Guquan ±1100 kV UHV project was approved by the state in December 2015 and started construction in January 2016. At Guquan Converter Station in Xuancheng City, Anhui, passing through Gansu, Ningxia, Shaanxi and Henan; the line has a total length of 3,293 kilometers, a rated voltage of ±1100 kV, and a transmission capacity of 12 million kilowatts. It is currently the world’s highest voltage level and largest transmission capacity. The power transmission project with the longest transmission distance and the most advanced technology.

±1100 kV UHV DC transmission is the latest innovation in my country's electric power field. It adopts advanced high-voltage, high-current, low-loss commutation technology and equipment manufacturing technology to successfully realize the comprehensive "DC voltage, AC voltage and transmission capacity" Upgrade, for the first time to have the ability to transmit tens of millions of kilowatts of power within a range of 3,000 to 5,000 kilometers, is a major technological leap and an important milestone in the field of international high-voltage power transmission. The transmission capacity of a ±1100 kV DC project can meet about half of the electricity demand of a medium-developed province in my country, and the economic transmission distance can meet the needs of transnational and intercontinental power transmission, which can greatly improve the power system's ability to optimize the allocation of resources .

The Changji-Guquan ±1100 kV UHV DC transmission project starts at the Zhundong Changji Converter Station in Xinjiang and ends at the Guquan Converter Station in South Anhui, Anhui Province. The DC line is about 3,324 kilometers and the transmission capacity reaches 12 million kilowatts, which is the highest voltage level in the world. UHV DC transmission project with the largest transmission capacity, the longest transmission distance, and the most advanced technology. The Changji-Guquan Project is a key project that promotes the adjustment of my country's energy structure, and has significant economic, social and environmental benefits. After being put into operation, 60-85 billion kilowatt-hours of electricity can be transmitted from Xinjiang to East China each year, reducing coal transportation by 38 million tons. It will promote the development of Xinjiang energy bases, ensure reliable power supply in East China, and promote the implementation of the air pollution prevention and control action plan.

The Changji-Guquan ±1100 kV UHV DC transmission project uses more than 14,000 pieces of ultra-high voltage DC composite insulators produced by Xiangyang Guowang Composite Insulator Co., Ltd. The product has successfully completed relevant routine tests, type tests, design tests, sampling tests and other tests, and the production and transportation of the products have also been completed within the delivery period specified in the contract. It can be said that the supply of composite insulators has been completed with quality and quantity. So far, the product with voltage of 1000KV and SML of 160KN-550KN has not been found any quality problems.