Supporting Scripts for Stability Analysis on Type-III Wind Generators

Impedance-based models of wind generators are widely used to analyze unstable oscillations between the grid and the control system of wind park generators. However, it is unclear what are the key control parameters that must be considered in the models at different frequency ranges (subsynchronous, near synchronous and high frequencies). The models can be either highly detailed, at the expense of complex algebraic derivations, or oversimplified, but unable to reliably predict control-to-grid instabilities. In this context, the companion paper proposes three simplified impedance models of Type-III generators for these stability studies. Initially, a systematic method based on a descriptor state-space formulation is developed to obtain the impedance model with all control components considered independently so that they can be added/removed without extensive manipulations. Then, a detailed investigation is conducted to identify the critical control components at three different frequency ranges and delimit a minimum set of key components that must be considered in the impedance model. Between 35% and 80% of the control variables are eliminated with these simplifications. The “minimum” impedance models enable a better understanding of the likeliest root causes of different types of control-to-grid instabilities and can facilitate fine-tuning the controllers to prevent these events. This dataset consists of the scripts to build the fully detailed model and the simplified models proposed in this work. The stability studies with the proposed impedance models are also presented. The script also contains validation studies with detailed electromagnetic transient simulations.