Effect of Wind Farm Spatial Correlation on Oscillation Damping in the WECC System

This paper studies the effect of spatial correlation between wind speed of geographically close wind farms on the damping of electromechanical oscillations in the Western Electricity Coordinating Council (WECC) system. Three correlation cases are analyzed based on the measured wind speed in the west coast. The damping of electromechanical oscillations is evaluated by studying all system modes expressed in the oscillation energy and total action. Monte Carlo simulations are performed to obtain different probability density functions (pdfs) of the total action for different correlations and dependence structures. The simulations show that, when wind farm correlations are disregarded, the probabilities for a critical dynamic performance are overestimated, which may lead to misguided planning and operation.