Losses minimization in a variable speed field-oriented controlled induction generator

A strategy to control an induction generator (IG), working with variable speed and load, is presented and discussed in this work. The objective of the proposed system is to make it work as a stand alone (not grid connected) generator to produce electrical DC energy, charging a battery bank and/or feeding DC loads with maximum efficiency. An inverter and a field-oriented controller are used to excite efficiently (minimizing system losses) the IM, regulating the generated voltage and rectifying the AC current. A laboratory set up was mounted to experimentally validate the proposal. This prototype is based on a conventional 4 kW squirrel cage IM. Simulation and experimental results were carried out to validate this proposal