Hu Tao

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.

Power connection technology for full-digital real-time simulation and analog simulator

The study of UHVAC/UHVDC hybrid power grid demands various means in every stage, such as in planning, designing, building and operating. Full-digital real-time simulator has the merits such as very large simulation scale and very easy modified model. And analog HVDC simulator has the merits such as reliable and precision simulation results. To bring the merits of these two simulators into play, a power connection technology for combining them is developed, which is developed by distributed parameters transmission line model. Using this power connection technology, a hybrid simulation model for a simple AC/DC hybrid power grid is set up. Results of load flow, start-up and fault test show that this power connection technology is precision, stable and practical, thus it suits to realtime simulation for parallel operation of AC/DC hybrid power grid.