Designing of wide-area damping controller for stability improvement in a large-scale power system in presence of wind farms and SMES compensator

摘要

The main aim of this paper is the stability improvement of a large-scale power system including wind farms and SMES (Superconducting Magnetic Energy Storage) compensator. For this purpose, at first, the mathematical model of the whole system is extracted in order to accurately investigate the role of wind farms and SMES in the stability studies. The stability analysis is based on the design of damping controllers which is provided through the global signals dependent on the time delay and local signals without the time delay. In modeling of the time delay, damping factor of inter-area oscillation mode is used to obtain larger delay margin, and then, the Lyapunov-Krasovskii function and inequality integral are employed to evaluate the stability condition related to the time delay. The controllability/observability index is used to choose the best candidate signals in the input of WADC (Wide-Area Damping Controller) in order to enhance the residual value of the weakest critical mode identified by modal analysis. The simulation results are investigated through different scenarios of wind turbine and power system in non-linear time domain as well as frequency domain using eigenvalues analysis. The results verify the effectiveness of the proposed controller under various time delays.