Development of 20 MVA static synchronous compensator

Static synchronous compensator (STATCOM) has been proved to have a number of advantages over other techniques available at present in stabilizing power transmission systems. To improve the stability of the power transmission system of China´s Henan province, the Henan Electric Power Company and Tsinghua University have jointly investigated and developed a 20 MVA STATCOM employing GTO inverters. The STATCOM consists of four six-pulse voltage source inverters (VSIs) unit rated 5 MVA which use 48 GTOs rated 4500 V, 4000 A. The STATCOM has been installed in a 220 kV substation and has been put into operation successfully since April 1999. The field tests have been carried out to verify the performance and the long-term reliability of the installation. The outline, technical features and field test results of the 20 MVA STATCOM are given in this paper