Ramp-Rate Risk Characterization and Comparison using Survival Theory

The increasing penetration levels of wind energy predicates informed assessment of power system risk. There is potential to alleviate the required post-hoc rectification of the demand/generation imbalances in the planning phase. This may be accomplished through the development of planning tools which assess the potential relative wind farm risk for loss of generation events. This paper describes the application of survival analysis techniques to specified ramp-rate exceedances in pursuit of the quantification of relative risk. The methodology is demonstrated on the measured wind speeds of two meteorological masts. The wind speed measurements are subsequently upscaled to aggregated wind farm power using existing techniques. Events are extracted from the power series for specified ramp-rate exceedances. Finally, the Cox proportional hazards model is applied to estimate relative temporal risk of the occurrence of events. This method may be applied, with minor adjustments, to generate relative risk maps to inform effective wind farm siting.