| Since the series capacitor compensation is used in the extra-high voltage long distance transmission system,in a certain operation mode or compensation degree,subsynchronous resonance will occur.SSR is a very dangerous state which may occur in power system operation.When the electric resonance frequency adds one of the inherent surge frequency of synchronous generator axis.The coupling surge of electric-machine system will occur,the most serious accident is the synchronous generator axis will be twist break.Static var compensator is a member of FACTS family,which is widely used to compensate the load and transmission line of modern power system.As the fast and flexible adjustment ability of SVC, it becomes useful tools to damping SSR.This paper analyzed the basic principle of SSR,and according to the mathematic model of SVC,simulated SVC damping SSR.Based on the real project,the effects of the static var compensator on damping the subsynchronous resonance are simulated and analyzed in time domain by the RTDS.The simulation results show that the static var compensator can damp the subsynchronous resonance effectively with a simple proportional controller.The results are helpful to solving the subsynchronous resonance problems which exist in the series compensated transmission systems in China,and the conclusions also provide valuable references for better applications of the static var compensators. |
