Numerical effects in stability simulations of power systems with Wind turbine generators

Based on experience with stability models for a variety of wind turbine generator (WTG) technologies, the paper describes numerical effects that are either a manifestation of modeling problems or may be inconsistent with real WTG behavior. Effects such as low-frequency and high-frequency oscillations, peaks in variables, noise, excessive sensitivity to numerical solution and questionable tripping are often observed in stability simulations of power systems with WTGs and can mislead system planners. The paper describes these effects, discusses their mechanisms and makes recommendations to model developers and power system planners on how to prevent or minimize the negative impact of numerical effects on stability simulations.