Real-time simulation and parameter optimization for SVC control tragedy of XiZang grid

Since Qingzang HVDC system put into operation in 2011, higher requirements for voltage stability in Xizang grid must be taken into account. It plans to install several SVC devices at three 220 kV stations which include Duodi, Naiqiong and QuGe, in order to improve the voltage quality of Xizang Grid and the transmission capacity of QingZang HVDC system. To optimize and validate the control tragedy of these SVCs before their installation, a real-time digital/analog hybrid simulation platform is setup by HYPERSIM. This platform is composed of a digital model which includes detail 220 kV and 110 kV network of XiZang grid, an analog HVDC controller for Qingzang HVDC system, and all the analog SVC controllers. It includes two types of SVC devices for the real project, one is TCR+SC, and another is TSC. Based on the simulation platform, the SVC control tragedies of these two types are validated respectively. The simulation results show: through adding SVC devices at the 220 kV stations, the Xizang grid has better voltage recover characteristic after short-circuit fault. It can draw a conclusion that the voltage control tragedy used in this real project has favorable control characteristic for the voltage stability of Xizang Grid.