The effect of a static synchronous series compensator on transient properties of the system

Abstract

Developments in the power converter technology field create the prerequisites for the emergence of flexible alternating current transmission systems of the second-generation devices, namely the advent of transformerless static synchronous serial compensator (SSSC). These technologies enable to extend the application of the series connected FACTS devices to increase the transmission capacity of lines and to improve the system controllability. Thus, the integration of this appliance provides an opportunity to overcome many technological limitations. In this regard, the purpose of this master’s thesis is to study the impact of the SSSC on operation modes and transient processes in the electric power system, namely the effect of SSSC control gains on the steady-state and transient stability. Results of mathematical modeling have shown the detrimental influence of the SSSC negative current proportional gain on critical fault clearance time. Therefore, with these controller settings, the facility should be switched out of operation or into a mode with a positive sign, which favorably affects the stability by increasing fault clearance time. Steady-state stability analysis was performed for tuned regulator channels, which were optimized using two methods: D-decomposition and simultaneous coordination of controller settings. Where was obtained that the same damping degree can be achieved for different current control channel values with corresponding changes in the regulator channels on generator rotor slip or voltage frequency at the connection point.