Stability analysis and control of a SMDL system with TCSC

This paper presents the stability analysis and control of a single-machine dynamic load (SMDL) system with a thyristor-controlled series capacitor (TCSC). Firstly, the aim of this study is achieved by analyzing the stability of the SMDL system with and without the TCSC. The simulations obtained with the aid of MATLAB/Simulink software showed that without the TCSC, the system presents a saddle-node bifurcation (SNB) which is a type of local bifurcation that is associated with voltage collapse and dynamic instability in power systems. However, with the connection of TCSC, the loadability of the system increased. In addition, it is observed that although SNB is avoided, the system becomes unstable due to the presence of a real and positive eigenvalue. As a result, a linear quadratic regulator optimal control technique was employed to stabilize the SMDL system with TCSC.