A stand alone induction generator model producing a constant voltage constant frequency output

Mathematical modelling, design and development of ldquoa variable speed constant frequency self-excited induction generator (IG)rdquo using field-oriented techniques for its voltage and frequency control is described. A space-phasor model for the generator is developed to implement Indirect Field Oriented Control. To study the generator dynamic response the machine was driven by a separately-excited DC motor simulated as a variable speed turbine and a 2.2kW wound rotor IM as an IG. The excitation current for the wound rotor induction generator (variable frequency, 3-phase sinusoidal current) was provided by a current-controlled voltage-source inverter (CCVSI). The generator closed-loop control performance has been studied under varying load and wind speed conditions. Simulated results are compared with experimental data to validate the proposed control system.