Sliding Mode Observer based Fault Tolerant Controller of UPFC for power flow tracking

This article presents a Sliding Mode Observer based Fault Tolerant Control (SMOFTC) applied to a Unified Power Flow Controller (UPFC) to achieve rapid and finite time reference signal tracking of power flow in presence of actuator faults. SMOFTC is a nonlinear control based on a Sliding Mode Observer (SMO), the Lyapunov stability and variable structure control theories to compensate for actuator faults. In this article, we first establish a state space complete dynamic model of UPFC based on Kirchhoff equations and (d-q) transformation, and then SMOFTC law is developed for the UPFC system. The proposed control is validated via a detailed simulation on a two bus system. Simulation results show power, effectiveness, robustness and accuracy of the proposed controller.