Applications of pwm based static synchronous series compensator (SSSC) to enhance tranient stability of power system

The static synchronous series compensator (SSSC) is a FACTS device, which allows rapid and continuous changes in the transmission line impedance so that the active power flow along the compensated transmission line can be controlled within a specified range under a range of operating conditions and can help to improve the dynamic performance of power systems. This paper presents the analysis of the dynamic performance of a PWM based static synchronous series compensator (SSSC) and its interaction with a representative two-area EHV network. The detailed switching-level SSSC devices as well as the power systems models were developed in SimPowerSystems (MATLAB), which was used to evaluate the static and dynamic performances of the series compensated system. Various control strategies were evaluated and an adaptive PI controller was developed. Study results show a substantial improvement in the response of the network to system disturbances, with minimum harmonic distortion.