A reduced order model and control for a wind turbine induction generators

Self Excited squirrel cage Induction Generator (SEIG), is used widely to convert mechanical wind energy to electricity, due to their low cost, small size, no need of separate dc source and brushes. This paper proposes a new reduced order model for small wind energy system consisting of: Squirrel Cage Induction with excitation capacitors, D-Statcom, loads and mechanical parameters. Comparing with conventional high order model, the presented model gives a physical insight and clearly describes the dynamic behavior of frequency and voltage of a SIEG supplied system during isolating from a power system grid. Based on the proposed model, qualitative analysis and controller design method for voltage and frequency control has been presented. These proposed controllers are applied on a 33 kv wind energy system, and compared with high order model using MATLAB- Simulink. The simulation results verified the validity of the proposed models and control schemes.