Adaptive Fault Tolerant Control Design for Multimachine Power Systems

This paper presents an adaptive Fault Tolerant Control (FTC) design for nonlinear power systems with unknown actuator failures. The method is based on the efficient multi input-multi-output linearization technique. Inexact cancellation of terms due to uncertainties may result in performance deterioration like inter-system oscillations. Adaptation in estimated parameters is utilized to achieve an asymptotically exact cancellation of terms. It is shown that the adaptive control results in bounded states and maintains the desired performance The power system considered here is comprised of two generators connected to a load and an infinite bus through a transmission network. First, the derivatives of the system’s output is calculated repeatedly, in order to find the relative degree of the system. Then the dynamics of the power system are linearized by using the feedback linearization technique. Subsequently, a nominal adaptive controller is designed to stabilize the system. In the proposed approach, if an actuator failure happens, the derived adaptive fault tolerant controller accommodates its effect. Simulation results demonstrate the effectiveness of the adopted fault tolerant control scheme.

Keywords:

Multimachine system , Adaptive feedback linearization control , Generator excitation control , Fault Tolerant Control