Design aspects of the Chinese 500 kV thyristor controlled series compensation scheme TCSC Tian Guang

In the late summer of 2002 the Tian Guang series compensation scheme located in the Tianshengqiao-Guangdong 550 kV ac-network has been ordered by State Power South Company and was designed by SIEMENS company for delivery, supervision of erection and commissioning. The power demand of the growing Chinese industries requires an economical solution for an increase of power transfer capability and stability with the existing lines. A combination of fixed and controlled series compensation has been found as the appropriate choice not only to enable the desired power increase, but also to stabilize the two interconnected strong networks by reducing the connecting line impedance. Both capacitors, located in the two parallel lines, are operating since mid of November 2003. This paper will give an overview of the design philosophy of the compensation system and for the choice of the component rating for the fixed as well as the controllable segment of the series capacitor scheme.