A robust nonlinear excitation and SMES controller for transient stabilization

Abstract

The transient stability control of a power system is a typical nonlinear control problem. Although many controller design approaches have been developed, most of the existing controllers are designed by using linear control theory. In this paper, a robust nonlinear controller for the generator field excitation and thyristor-controlled superconducting magnetic energy storage (SMES) unit is proposed to enhance the transient stability of a power system with unknown or varying parameters like equivalent reactance of the transmission lines. The SMES unit is located near the generator bus terminal in a power system. Our computer simulation results demonstrate that the proposed controller is robust and it can ensure transient stability of a single-machine, infinite-bus system under a large sudden fault that may occur near the generator bus terminal.