Series compensation device can improve significantly the transmission capability of the system and enhance system stability.The localization upgrading of series capacitor compensation is important to the development of power industry in China.In this paper

the scheme of localization upgrading of the Dongsan Ⅰ、Ⅱ lines Siemens’s series capacitor compensation secondary system in Sanbu substation is technically introduced and the upgrading performance of different module is evaluated.It is shown by the practice that the localization upgrading of Siemens’s series capacitor compensation secondary system in Sanbu substation possesses high application value.