Lyapunov Exponent based Stability Assessment of Power Systems

Lyapunov exponent (LE) is a mathematical-based analysis tool to assess the stability of dynamical systems and this can be done by two approaches: model-free approach and model-based approach. In this paper, the model-based approach is employed as an indicator of stability for the stability analysis of power systems. The maximum Lyapunov exponent (MLE) is used to investigate the effects of increasing load on the stability and stability region of the power system where the positive (negative) value of MLE means instability (stability). Also, LEs are used to assess the effect of the presence of renewable energy on the stability of power systems. Simulation results are presented on the single-machine system and fixed-speed induction generator (FSIG) wind turbine system which show the disadvantages of increasing load or adding renewable energy sources on the system stability.