Research On Restrain SSR Based On Facts Technology

The series capacitor compensation, which is an important measure as the improvement of the transimission line's transimission ability, has been more and more emphasized in power network planning in our country. But after the series capacitor compensation is used in the extra-high voltage long distance transimission system, sub-synchronous resonance(SSR) will occur. SSR is a very dangerous state which may occur in power system operation. When the electric resonance frequency approximatively adds one of the inherent surge frequency of synchronous generator axis. The coupling surge of electric-machine system will occur, the serious accident is the synchronous generator axis will be twist off and the grave economy loss will be result in. Therefore, the research on the SSR which is produced by the series capacitor compensation and countermeasures to prevent its electric-machine resonance is one of an impartment subjects in the safe and stable operation of power system.Flexible AC Transmission System (FACTS) will be widely used in power system, it is one of the burgeoning subjects of power system in recent years. As the fast and flexible adjustment ability of FACTS equipment, many application fields of power system have pay more attention to it, and it provides useful tools to restrain SSR.The basic principle of SSR of synchronous generator is analyzed in this paper firstly. And making Mathematical models of SSR, Using simulation software MATLAB/SIMULINK to make models which basis on analysis of Mathematical Modeling.In terms of hierarchical structure, the paper specified base the operating principle of STATCOM and SMES, and building their mathematical model. Using simulation software MATLAB/SIMULINK to make models which basis on analysis of Mathematical Modeling. It contains the circuit improve, building main circuit of large capacity STATCOM with multiple configuration. Using the controller of indirect current control test and verify that, using STATCOM can gain the ends of reactive compensation and the synchronous generator axis will never augmentation .In the end, the paper targeted the first IEEE SSR benchmark model, research a method of damping SSR of power system using STATCOM and SMES. This method base on the method of complex torque coefficient. Referring to the basic idea of the method of complex torque coefficient, the expression about the electric complex torque coefficient and mechanical one was derived, also the control strategy to damp the SSR was proposed as well as PI controller was designed. The simulation results showed the validity and correctness of this method.