Multi‐DFIG aggregated model based SSR analysis considering wind spatial distribution

This study investigates the impact of wind spatial distribution on sub-synchronous resonance (SSR), considering wind speed difference and wind turbine division. For a doubly-fed induction generator (DFIG) wind farm, two equivalent aggregated models, i.e. a one-DFIG model and a multi-DFIG model, are established and both simplified to impedance model for investigation. In one-DFIG model, the SSR mechanism in DFIG wind farm, and the impact of wind speed on SSR are discussed. The concept of damping is introduced to explain how DFIG SSR current changes under the negative resistance of wind farm. Then, in multi-DFIG model, DFIGs are divided into different groups based on their wind speed, and the interaction between DFIG groups is investigated. Simulations are used to validate the proposed analysis, and the results show that, multi-DFIG model performances a higher accuracy when dealing with DFIG wind spatial distribution problems compared with one-DFIG model.