Impacts of Correlated Input Variables on Small Signal Stability of Wind Generator-Connected Power Systems

In this paper the impacts of correlated input variables on small signal stability of a power system consisting of intermittent wind generation is presented. The input variables consist of the wind power, the nodal loads and the generation dispatch. The analysis is conducted using Monte Carlo Simulation via modal analysis on three area network system interconnected by tie lines. The probabilistic models of the input variables are first derived. The damping ratio of the power system with the input variables correlated are calculated and then compared with the uncorrelated one. The coefficient of variation is used as an index to determine the fluctuation in the damping ratio as a result of fluctuation in the input variables for both cases. The results show that the coefficient of variation is higher when the input variables are correlated. This indicates that correlated input variable gives the worst case scenario compared to the uncorrelated input variables. Index Terms —Small signal stability, Power system, Monte Carlo simulation, Latin hypercube sampling

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