Optimization of the Performance of a Grid-Connected Induction Generator

Wind-turbine driven Induction generators find nowadays increasing applications for utilizing the renewable wind energy. In the present paper, the performance of the grid-connected induction generators has been optimized under different driving torques. Closed formulas for the optimizing slips based on a circuit model having linear parameters have been derived. The optimizing slip is obtained such that the optimized performance criteria are either minimizing the output current, maximizing the output power, minimizing the total losses, minimizing the input reactive power, maximizing the motor efficiency, or maximizing the power factor. Also, a computer-implemented algorithm, which scans the performance characteristics of the generator, and determines the optimizing slips, has been developed. The algorithm takes into consideration the electromagnetic nonlinear effects upon the generator parameters. Experimental tests have been carried out on a laboratory setup, and the computed results have been compared with the measured ones. The comparison confirmed the validity of the presented optimization theoretical techniques.