Abstract
We numerically investigate the influences of Gaussian white noise on the dynamical behaviors of a power system. The studied model is described by the classical single-machine infinite-bus (SMIB) system with the values of parameters at which the system is stable. It is found that with increasing noise intensity σ, the power system becomes unstable and falls into chaos as σ is further increased. These phenomena imply that random noise can induce and enhance chaos in the power system. Furthermore, the possible mechanism behind the action of noise is addressed basing on the stochastic Melnikov method. Our results may provide a useful tip for understanding power system's security operations.