1. Modal analysis of a grid‐connected DFIG‐based WT considering multi‐timescale control interactions
- Author
-
Minhui Wan and Jiabing Hu
- Subjects
Wind power ,Computer science ,business.industry ,Rotor (electric) ,020209 energy ,Modal analysis ,020208 electrical & electronic engineering ,General Engineering ,Energy Engineering and Power Technology ,02 engineering and technology ,AC power ,Grid ,Turbine ,law.invention ,Phase-locked loop ,Control theory ,law ,0202 electrical engineering, electronic engineering, information engineering ,business ,Software ,Machine control - Abstract
In a grid-connected doubly fed induction generator (DFIG)-based wind turbine system, the multi-timescale control loops of DFIGs work together to keep the output active/reactive power tracking their references. In weak AC grid condition where the grid impedance cannot be neglected, interactions among those control loops are very strong. This study presents a modal analysis of the system containing a DFIG. The DFIG model for analysis considers multi-timescale control and its interactions. The effect of bandwidths of rotor speed control, phase-locked loop, DC-link voltage control and rotor current control on system stability is presented. Interactions among those control loops are explored. The analysis results indicate that the interactions among multi-timescale control are strong and will have an effect on the stability and the dynamics of the DFIG system under weak AC grid condition.
- Published
- 2017