Robust decentralized control for multimachine power systems

Abstract

In this paper, a new robust linear decentralized controller is proposed to enhance the transient stability of nonlinear multimachine power systems. Only local measurements are required in the proposed controller. The feedback gain of each generator is obtained by solving an algebraic Riccati equation based on the bounds of the machine parameters. The stability analysis shows that the decentralized controller can guarantee the system stability over the whole operating region and regardless of fault locations or parameter uncertainties of the transmission network. Compared with nonlinear controllers, linear controllers are of simpler structure and easier to be implemented. A three-machine power system is considered as an application example. Simulation results show that despite the interconnections between different generators, nonlinearities in the system, different operating points, and different fault locations, the proposed robust decentralized controller can greatly enhance power system transient stability.