On the Dynamic Coupling of the Autocorrelation of Stochastic Processes and the Standard Deviation of the Trajectories of Power System Variables

The paper originates from the observation that, due to the nonlinearity of the power system model, the autocorrelation of noise impacts on the standard deviations of the trajectories of the variables of the system in an unpredictable way. A case study based on the well-known two-area system with inclusion of stochastic load models is presented. Simulation results show that an increase of the autocorrelation of load consumption causes a significant increase of the standard deviation of the active and reactive powers generated by the synchronous machines. In some scenarios, the increase of the autocorrelation gives rise to instability and drives the system to voltage collapse.