Nonlinear backstepping design of robust adaptive modulation controller for TCSC

In this paper, a nonlinear robust adaptive modulation controller (RAMC) for thyristor controlled series capacitor (TCSC) in interconnected power systems is developed. The controller drives centers of inertial of different areas (COIs) to maintain synchronous operation based on the dynamic COI signals obtained from the wide area measurement system (WAMS). The overall system model is established using COI coordinates. The control law of the RAMC is then derived using the backstepping method, and not only is it adaptive to unknown parameters such as damping coefficients of generators, but also robust to uncertain disturbances and model errors. Computer simulation results illustrate that the proposed controllers can improve system dynamic more effectively when compared with conventional linear controllers