Simple Control for a Wind-Driven Induction Generator

Global environmental concerns and the ever-increasing need for energy spur the search for new opportunities to use renewable energy sources. Harnessing electrical energy from wind power is a cost-effective and cleaner option. The generated power can be fed directly into the grid or used to feed the local loads. The self-excited induction generators are becoming popular with the proliferation of such nonconventional energy sources as wind, small hydro projects, etc. The induction generators (particularly squirrel-cage induction generators) have robust construction, lower initial and run-time cost (due to brushless construction), and lower maintenance cost [1], The induction generators are suitable for grid-connected as well as standalone applications. In grid-connected mode, the excitation current to the induction generator is supplied through the grid. A mechanical arrangement is used to maintain the rotor speed above the synchronous speed. In self-excitation mode, the excitation current is supplied by a local source.