Field-oriented controlled induction generator with loss minimization

In this paper, a strategy to control an induction generator (IG) working with variable speed and load is presented and discussed. An inverter and a field-oriented controller are used in order to excite the induction machine (IM) efficiently, minimizing copper and iron losses, and to regulate the generated voltage. The proposed IG system is a stand-alone (not grid connected) system. It is used to produce electrical dc energy, to charge a battery bank, and/or to supply dc loads with maximum efficiency. A laboratory setup, based on a conventional 4-kW squirrel-cage IM, has been implemented. Experimental results are presented in order to validate the proposed strategy.