Nonlinear adaptive robust control for thyristor controlled series compensation

The backstepping design methodology of the nonlinear control theory is known to provide an efficient controller constructive tool for a wide range of systems engineering applications. Based on the nonlinear second-order model of single machine to infinite bus system employing thyristor controlled series compensation, a novel nonlinear adaptive robust controller is proposed by combining the backstepping method with Nussbaum gain function. The constant parameter uncertainty and the exogenous disturbances of the system are taken into consideration together in control design procedure, thus not only can the derived adaptive robust controller and parameter update law guarantee the closed-loop system globally uniformly ultimate bound, but also the desired performance can be achieved by an appropriate choice of design parameters. Simulation results demonstrate that the derived adaptive nonlinear controller owns superior robustness and adaptability.