On December 31, 2018, China's design and construction of the world's first ±1100 kV UHV DC transmission project - Changji - Guquan ± 1100 kV UHV project successfully started full-voltage power transmission.

The project was approved by the state in December 2015 and started construction in January 2016. It started at Changji Converter Station in Changji Hui Autonomous Prefecture of Xinjiang, and stopped at Guquan Converter Station in Xuancheng City, Anhui Province, passing through Gansu, Ningxia, Shanxi and Henan. It has a 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 transmission line with the highest voltage level, the largest transmission capacity, the longest transmission distance and the most advanced technology.

 ±1100 kV UHV DC transmission is the latest innovation in China's electric power field. It adopts advanced high voltage, high current, low loss commutation technology and equipment manufacturing technology to successfully realize the full range of "DC voltage, AC voltage and transmission capacity". For the first time, it has the ability to transport tens of thousands of kilowatts of power in the range of 3,000 to 5,000 kilometers. It is a major technological leap and important milestone in the international high-voltage transmission field. The transmission capacity of a ±1100 kV DC project can meet about half of the electricity demand in a medium-developed province in China. The economic transmission distance can meet the needs of cross-border power transmission and inter-continental power transmission, it can greatly improve the resource optimization and allocation capability of the power system.

Xinjiang is one of China's five major comprehensive energy bases, with conditions for large-scale development of coal, wind and solar power. The quality of coal resources in the Zhundong area is excellent and the development conditions are good. It is suitable for local power generation. The proven coal reserves are 213.6 billion tons. The planned production capacity in the near future can support 40 million kilowatts of coal-fired power installed capacity. Xinjiang is one of the nine large wind power bases planned and built by the state, with a development capacity of more than 200 million kilowatts. The use of advanced UHV transmission technology to implement large-scale "transportation of Xinjiang Power" can effectively promote the intensive development of Xinjiang energy bases and turn resource advantages into economic advantages. Changji-Guquan ±1100 kV UHV DC project is a landmark project of “Gangzhou Power Transmission”, which is of great strategic significance for promoting the development of Xinjiang energy base, stimulating economic growth, achieving healthy and rapid development and long-term stability.

The economy in East China is developed, the contradiction between power supply and demand is tight, the land resources are in short supply, and the atmospheric environment is under great pressure. It is no longer necessary to further expand the conditions for coal-fired power installations. It is urgent to accelerate the development of calls outside the region. Changji-Guquan ±1100 kV UHV DC project is the “Electric power Silk Road” connecting Xinjiang and East China. It can send 66 billion kWh of electricity to East China every year to meet the electricity demand of 50 million households. It can reduce coal transportation by 30.24 million tons per year; if it is calculated by train capacity, it needs 25,000 to 20 trains of trains, which is of great significance for winning the blue sky.

It is understood that Changji-Guquan's investment of ±1100 kV UHV DC project reached 40.7 billion yuan, increasing the output value of power transmission and transformation equipment manufacturing industry by 28.5 billion yuan, directly driving related industries such as power supply and investment of 101.8 billion yuan, and increasing employment of 28,000 jobs. Every year, the GDP growth rate is 13 billion yuan, and the tax revenue is 2.4 billion yuan.

By JUCRO Electric(Focus on Vacuum interrupter, Vacuum circuit breaker, Vacuum contactor and Switchgear)