Simulation and Experimental Studies on Double-fed Induction Generator Power Control at Subsynchronous Operating Speed

Two control schemes for active and reactive power of a double-fed induction generator with the stator connected direct to the constant frequency, three phase grid are described. First the direct and quadrature rotor current components are generated based on the mathematical model of the machine. The second scheme used a PI controller to generate the rotor current reference components. The principles of both schemes are described in detail in this paper with a strong experimental approach. A complete simulation model is developed and several studies are performed to test its under different conditions. A laboratory test setup consisting of a wound rotor induction machine and driven by a variable speed squirrel cage induction motor is used to validate the control schemes proposed and the simulation results.