Abstract:

Yunnan-Guangdong UHVDC project is the first ultra high voltage DC transmission project with ±800 kV in the world. In this paper, the voltage calculation formulas are presented of single valve group and double valve groups with and without DC line in the open line test (OLT). Taking the open line test of single valve group and double valve groups in Suidong converter station as an example, the relationship and the error between the measured and the calculated results of open circuit voltage are analyzed. It is concluded that the voltage protection should not be applied in open line test.