4.3. Validation bench
As mentioned earlier, underperformances were simulated in order to validate the proposed methodology as a function of variation level. It was assumed that all bins of the power curve between the cut-in and the nominal wind speed would undergo suffer the same relative shift. Two types of variations were considered: a step change and a ramp change. The step reached its nominal value immediately (e.g. a one-shot 5% step reducing the entire power curve) while the ramp was denominated on an annual basis (e.g. a 5% variation over one year, meaning that after one year the power curve would be reduce by 5%). A ramp shift is the best way to represent of consequence of problems such as blade erosion, while step shift give the best representation of sudden changes in components.