Alstom has delivered wall bushings of 800kV and 400kV to State Grid Corporation of China (SGCC).
The units have been designed for China Xiloudu-Zhexi 800 kV Ultra High Voltage Current (UHVDC) transmission line.
The project intends to meet the electricity demands of Eastern provinces in China.
A 1,671km long transmission line will be used to transport the power generated by Xiloudu Hydro Power Plant in Sichuan province to Jinhuan City in Zheijang.
Alstom Grid senior vice president for China and East Asia Pacific Region Michel Serra said: "This commercial success well positions Alstom for future challenges of the UHVDC in China.
"Despite the project’s high-voltage grade, Alstom’s bushing team in Milan (Italy) has successfully managed the challenge and completed the project ahead schedule.
"Today, we are a world leading supplier of bushings, able to manufacture equipment up to 1 100 kV AC and 800 kV DC."
Alstom Grid designs, manufactures and installs the power transmission and distribution products and systems globally for low carbon economy.
The company employs 17,000 people in 87 manufacturing and engineering sites worldwide.