Power system transient stability enhancement with an adaptive control scheme using backstepping design

In this paper, a nonlinear feedback excitation control is presented for power systems with uncertainties. In order to achieve the transient stability enhancement, the control law can be designed based on the adaptive backstepping method by a recursive way without linearization. Lyapunov function method is applied to analysis the convergence of the power angle and relative speed of the generator and the active electrical power delivered by the generator with the designed controller when a large fault occurs. Compared with the adaptive control approach based on direct feedback linearization (DFL) technique and the robust nonlinear DFL controller, the proposed controller has two prominent advantages: firstly, it can greatly improve transient stability as compared to the DFL technique based on adaptive control approach; secondly, it doesn't require that the solution of a designed algebraic Riccati equation exists in contrast to the robust nonlinear DFL controller. Simulation results show that transient stability enhancement and voltage regulation of a power system can be achieved under a large sudden fault. Furthermore, the robustness property of this new controller is analyzed for both uncertainties in model parameters and the presence of unmodeled inter-area disturbances.